tretinoin and Disease-Models--Animal

As one of the most important metabolites of vitamin A, all-trans retinoic acid (RA) plays a crucial role in regulating immune responses. RA has been shown to promote the differentiation of naïve T and B cells and perform diverse functions in the presence of different cytokines. RA also induces gut tropic lymphocytes through upregulating the expression of chemokine (C-C motif) receptor 9 (CCR9) and α4β7 integrin. In addition, RA promotes the expression of the enzyme retinal dehydrogenase (RALDH) on dendritic cells, which in turn strengthens the ability to synthesize RA. Due to the insolubility of RA, proper formulation design can maximize its ability to improve immune responses for vaccines. Recent studies have developed some formulations co-loading RA and antigen, which can effectively imprint lymphocytes gut homing properties and induce intestine immune responses as well as systemic responses through parenteral administration, providing a promising direction for the protection against mucosal infections. Here, we review the mechanism and effects of RA on lymphocyte differentiation and gut homing, and recent progress of RA delivery systems to improve mucosal immune responses.

Topics: Adjuvants, Immunologic; Animals; B-Lymphocytes; Cell Differentiation; Dendritic Cells; Disease Models, Animal; Drug Carriers; Drug Compounding; Humans; Immunity, Mucosal; Immunogenicity, Vaccine; Intestinal Diseases; Intestinal Mucosa; Mice; Solubility; T-Lymphocytes; Tretinoin; Vaccine Excipients; Vaccines

Regulatory T (Treg) cells are a subtype of CD4

Topics: Animals; Disease Models, Animal; DNA (Cytosine-5-)-Methyltransferases; DNA Demethylation; DNA Methylation; Epigenesis, Genetic; Humans; Immune Tolerance; Promoter Regions, Genetic; Respiratory Hypersensitivity; Severity of Illness Index; T-Lymphocytes, Regulatory; Tretinoin

Dendritic cells (DCs) mediate tolerance to food antigens, limit reactivity to the gut microbiota and are required for optimal response to intestinal pathogens. Intestinal DCs are heterogeneous but collectively generate both regulatory and effector T cell responses. The balance of outcomes is determined by the activity of functionally distinct DC subsets and their modulation by environmental cues. DCs constantly sample luminal content to monitor for pathogens; the significance of the various pathways by which this occurs is incompletely understood. Intestinal DC have distinctive properties shaped by local host, dietary and microbial signals. These properties include the ability to produce all-trans retinoic acid (RA) and imprint gut tropism on T cells they activate. In the steady-state, subsets of intestinal DC are potent generators of inducible Treg, aided by their ability to activate TGFβ and produce RA. However, responses induced by steady-state intestinal DCs are not exclusively regulatory in nature; effector T cells with specificity for commensal bacterial can be found in the healthy mucosa and these can be locally controlled to prevent inflammation. The ability of intestinal DCs to enhance effector responses in infection or sustain inflammation in disease is likely to involve both modulation of the local DC population and recruitment of additional populations. Immune pathways in the pathogenesis of inflammatory bowel disease can be mapped to DCs and in inflamed intestinal tissue, DCs show increased expression of microbial recognition machinery, activation, and production of key immunological mediators. Intestinal DCs may be targeted for disease therapy or to improve vaccine responses.

Topics: Allergens; Animals; Cell Communication; Colitis; Dendritic Cells; Disease Models, Animal; Food Hypersensitivity; Gastrointestinal Microbiome; Humans; Immunity, Mucosal; Immunologic Factors; Intestinal Mucosa; Intraepithelial Lymphocytes; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Tretinoin

Vitamin A (VA) is amongst the most well characterized food-derived nutrients with diverse immune modulatory roles. Deficiency in dietary VA has not only been associated with immune dysfunctions in the gut, but also with several systemic immune disorders. In particular, VA metabolite

Topics: Animals; Cell Differentiation; Dendritic Cells; Disease Models, Animal; Homeostasis; Humans; Immunity, Innate; Intestines; Lymphocytes; T-Lymphocytes, Helper-Inducer; Tretinoin

Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA), acting through nuclear retinoic acid receptors (RARs), is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system.

Topics: Anemia, Iron-Deficiency; Animals; Cell Differentiation; Disease Models, Animal; Embryonic Development; Epigenesis, Genetic; Erythropoiesis; Erythropoietin; Female; Granulocytes; Hematopoiesis; Humans; Leukemia, Promyelocytic, Acute; Pregnancy; Receptors, Retinoic Acid; Signal Transduction; Tretinoin; Vitamin A; Vitamin A Deficiency

Middle East Respiratory Syndrome (MERS) is a novel respiratory illness firstly reported in Saudi Arabia in 2012. It is caused by a new corona virus, called MERS corona virus (MERS-CoV). Most people who have MERS-CoV infection developed severe acute respiratory illness.. This work is done to determine the clinical characteristics and the outcome of intensive care unit (ICU) admitted patients with confirmed MERS-CoV infection.. This study included 32 laboratory confirmed MERS corona virus infected patients who were admitted into ICU. It included 20 (62.50%) males and 12 (37.50%) females. The mean age was 43.99 ± 13.03 years. Diagnosis was done by real-time reverse transcription polymerase chain reaction (rRT-PCR) test for corona virus on throat swab, sputum, tracheal aspirate, or bronchoalveolar lavage specimens. Clinical characteristics, co-morbidities and outcome were reported for all subjects.. Most MERS corona patients present with fever, cough, dyspnea, sore throat, runny nose and sputum. The presence of abdominal symptoms may indicate bad prognosis. Prolonged duration of symptoms before patients' hospitalization, prolonged duration of mechanical ventilation and hospital stay, bilateral radiological pulmonary infiltrates, and hypoxemic respiratory failure were found to be strong predictors of mortality in such patients. Also, old age, current smoking, smoking severity, presence of associated co-morbidities like obesity, diabetes mellitus, chronic heart diseases, COPD, malignancy, renal failure, renal transplantation and liver cirrhosis are associated with a poor outcome of ICU admitted MERS corona virus infected patients.. Plasma HO-1, ferritin, p21, and NQO1 were all elevated at baseline in CKD participants. Plasma HO-1 and urine NQO1 levels each inversely correlated with eGFR (. SnPP can be safely administered and, after its injection, the resulting changes in plasma HO-1, NQO1, ferritin, and p21 concentrations can provide information as to antioxidant gene responsiveness/reserves in subjects with and without kidney disease.. A Study with RBT-1, in Healthy Volunteers and Subjects with Stage 3-4 Chronic Kidney Disease, NCT0363002 and NCT03893799.. HFNC did not significantly modify work of breathing in healthy subjects. However, a significant reduction in the minute volume was achieved, capillary [Formula: see text] remaining constant, which suggests a reduction in dead-space ventilation with flows > 20 L/min. (ClinicalTrials.gov registration NCT02495675).. 3 组患者手术时间、术中显性失血量及术后 1 周血红蛋白下降量比较差异均无统计学意义（. 对于肥胖和超重的膝关节单间室骨关节炎患者，采用 UKA 术后可获满意短中期疗效，远期疗效尚需进一步随访观察。.. Decreased muscle strength was identified at both time points in patients with hEDS/HSD. The evolution of most muscle strength parameters over time did not significantly differ between groups. Future studies should focus on the effectiveness of different types of muscle training strategies in hEDS/HSD patients.. These findings support previous adverse findings of e-cigarette exposure on neurodevelopment in a mouse model and provide substantial evidence of persistent adverse behavioral and neuroimmunological consequences to adult offspring following maternal e-cigarette exposure during pregnancy. https://doi.org/10.1289/EHP6067.. This RCT directly compares a neoadjuvant chemotherapy regimen with a standard CROSS regimen in terms of overall survival for patients with locally advanced ESCC. The results of this RCT will provide an answer for the controversy regarding the survival benefits between the two treatment strategies.. NCT04138212, date of registration: October 24, 2019.. Results of current investigation indicated that milk type and post fermentation cooling patterns had a pronounced effect on antioxidant characteristics, fatty acid profile, lipid oxidation and textural characteristics of yoghurt. Buffalo milk based yoghurt had more fat, protein, higher antioxidant capacity and vitamin content. Antioxidant and sensory characteristics of T. If milk is exposed to excessive amounts of light, Vitamins B. The two concentration of ZnO nanoparticles in the ambient air produced two different outcomes. The lower concentration resulted in significant increases in Zn content of the liver while the higher concentration significantly increased Zn in the lungs (p < 0.05). Additionally, at the lower concentration, Zn content was found to be lower in brain tissue (p < 0.05). Using TEM/EDX we detected ZnO nanoparticles inside the cells in the lungs, kidney and liver. Inhaling ZnO NP at the higher concentration increased the levels of mRNA of the following genes in the lungs: Mt2 (2.56 fold), Slc30a1 (1.52 fold) and Slc30a5 (2.34 fold). At the lower ZnO nanoparticle concentration, only Slc30a7 mRNA levels in the lungs were up (1.74 fold). Thus the two air concentrations of ZnO nanoparticles produced distinct effects on the expression of the Zn-homeostasis related genes.. Until adverse health effects of ZnO nanoparticles deposited in organs such as lungs are further investigated and/or ruled out, the exposure to ZnO nanoparticles in aerosols should be avoided or minimised.

Topics: A549 Cells; Acetylmuramyl-Alanyl-Isoglutamine; Acinetobacter baumannii; Acute Lung Injury; Adaptor Proteins, Signal Transducing; Adenine; Adenocarcinoma; Adipogenesis; Administration, Cutaneous; Administration, Ophthalmic; Adolescent; Adsorption; Adult; Aeromonas hydrophila; Aerosols; Aged; Aged, 80 and over; Aging; Agriculture; Air Pollutants; Air Pollution; Airway Remodeling; Alanine Transaminase; Albuminuria; Aldehyde Dehydrogenase 1 Family; Algorithms; AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; Alzheimer Disease; Amino Acid Sequence; Ammonia; Ammonium Compounds; Anaerobiosis; Anesthetics, Dissociative; Anesthetics, Inhalation; Animals; Anti-Bacterial Agents; Anti-HIV Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal, Humanized; Antifungal Agents; Antigens, Bacterial; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Antitubercular Agents; Antiviral Agents; Apolipoproteins E; Apoptosis; Arabidopsis; Arabidopsis Proteins; Arsenic; Arthritis, Rheumatoid; Asthma; Atherosclerosis; ATP-Dependent Proteases; Attitude of Health Personnel; Australia; Austria; Autophagy; Axitinib; Bacteria; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacterial Toxins; Bacterial Typing Techniques; Bariatric Surgery; Base Composition; Bayes Theorem; Benzoxazoles; Benzylamines; beta Catenin; Betacoronavirus; Betula; Binding Sites; Biological Availability; Biological Oxygen Demand Analysis; Biomarkers; Biomarkers, Tumor; Biopsy; Bioreactors; Biosensing Techniques; Birth Weight; Blindness; Blood Chemical Analysis; Blood Gas Analysis; Blood Glucose; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Blood-Brain Barrier; Blotting, Western; Body Mass Index; Body Weight; Bone and Bones; Bone Density; Bone Resorption; Borates; Brain; Brain Infarction; Brain Injuries, Traumatic; Brain Neoplasms; Breakfast; Breast Milk Expression; Breast Neoplasms; Bronchi; Bronchoalveolar Lavage Fluid; Buffaloes; Cadherins; Calcification, Physiologic; Calcium Compounds; Calcium, Dietary; Cannula; Caprolactam; Carbon; Carbon Dioxide; Carboplatin; Carcinogenesis; Carcinoma, Ductal; Carcinoma, Ehrlich Tumor; Carcinoma, Hepatocellular; Carcinoma, Non-Small-Cell Lung; Carcinoma, Pancreatic Ductal; Carcinoma, Renal Cell; Cardiovascular Diseases; Carps; Carrageenan; Case-Control Studies; Catalysis; Catalytic Domain; Cattle; CD8-Positive T-Lymphocytes; Cell Adhesion; Cell Cycle Proteins; Cell Death; Cell Differentiation; Cell Line; Cell Line, Tumor; Cell Movement; Cell Nucleus; Cell Phone Use; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Cell Transformation, Viral; Cells, Cultured; Cellulose; Chemical Phenomena; Chemoradiotherapy; Child; Child Development; Child, Preschool; China; Chitosan; Chlorocebus aethiops; Cholecalciferol; Chromatography, Liquid; Circadian Clocks; Circadian Rhythm; Circular Dichroism; Cisplatin; Citric Acid; Clinical Competence; Clinical Laboratory Techniques; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clostridioides difficile; Clostridium Infections; Coculture Techniques; Cohort Studies; Cold Temperature; Colitis; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type XI; Color; Connective Tissue Diseases; Copper; Coronary Angiography; Coronavirus 3C Proteases; Coronavirus Infections; Cost of Illness; Counselors; COVID-19; COVID-19 Testing; Creatine Kinase; Creatinine; Cross-Over Studies; Cross-Sectional Studies; Cryoelectron Microscopy; Cryosurgery; Crystallography, X-Ray; Cues; Cultural Competency; Cultural Diversity; Curriculum; Cyclic AMP Response Element-Binding Protein; Cyclin-Dependent Kinase Inhibitor p21; Cycloparaffins; Cysteine Endopeptidases; Cytokines; Cytoplasm; Cytoprotection; Databases, Factual; Denitrification; Deoxycytidine; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; 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Emergency Service, Hospital; Empathy; Emulsions; Endothelial Cells; Endurance Training; Energy Intake; Enterovirus A, Human; Environment; Environmental Monitoring; Enzyme Assays; Enzyme Inhibitors; Epithelial Cells; Epithelial-Mesenchymal Transition; Epoxide Hydrolases; Epoxy Compounds; Erythrocyte Count; Erythrocytes; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Esophagectomy; Estrogens; Etanercept; Ethiopia; Ethnicity; Ethylenes; Exanthema; Exercise; Exercise Test; Exercise Tolerance; Extracellular Matrix; Extracorporeal Membrane Oxygenation; Eye Infections, Fungal; False Negative Reactions; Fatty Acids; Fecal Microbiota Transplantation; Feces; Female; Femur Neck; Fermentation; Ferritins; Fetal Development; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fibroblasts; Fibroins; Fish Proteins; Flavanones; Flavonoids; Focus Groups; Follow-Up Studies; Food Handling; Food Supply; Food, Formulated; Forced Expiratory Volume; Forests; Fractures, Bone; Fruit and Vegetable Juices; Fusobacteria; G1 Phase Cell Cycle Checkpoints; G2 Phase Cell Cycle Checkpoints; Gamma Rays; Gastrectomy; Gastrointestinal Microbiome; Gastrointestinal Stromal Tumors; Gefitinib; Gels; Gemcitabine; Gene Amplification; Gene Expression; Gene Expression Regulation; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Neoplastic; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Gene-Environment Interaction; Genotype; Germany; Glioma; Glomerular Filtration Rate; Glucagon; Glucocorticoids; Glycemic Control; Glycerol; Glycogen Synthase Kinase 3 beta; Glycolipids; Glycolysis; Goblet Cells; Gram-Negative Bacterial Infections; Granulocyte Colony-Stimulating Factor; Graphite; Greenhouse Effect; Guanidines; Haemophilus influenzae; HCT116 Cells; Health Knowledge, Attitudes, Practice; Health Personnel; Health Services Accessibility; Health Services Needs and Demand; Health Status Disparities; Healthy Volunteers; Heart Failure; Heart Rate; Heart Transplantation; Heart-Assist Devices; HEK293 Cells; Heme; Heme Oxygenase-1; Hemolysis; Hemorrhage; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Hepatocytes; Hexoses; High-Throughput Nucleotide Sequencing; Hippo Signaling Pathway; Histamine; Histamine Agonists; Histidine; Histone Deacetylase 2; HIV Infections; HIV Reverse Transcriptase; HIV-1; Homebound Persons; Homeodomain Proteins; Homosexuality, Male; Hospice and Palliative Care Nursing; HSP70 Heat-Shock Proteins; Humans; Hyaluronan Receptors; Hydrogen; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hydrolysis; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemia; Hypoglycemic Agents; Hypoxia; Idiopathic Interstitial Pneumonias; Imaging, Three-Dimensional; Imatinib Mesylate; Immunotherapy; Implementation Science; Incidence; INDEL Mutation; Induced Pluripotent Stem Cells; Industrial Waste; Infant; Infant, Newborn; Inflammation; Inflammation Mediators; Infliximab; Infusions, Intravenous; Inhibitory Concentration 50; Injections; Insecticides; Insulin-Like Growth Factor Binding Protein 5; Insulin-Secreting Cells; Interleukin-1; Interleukin-17; Interleukin-8; Internship and Residency; Intestines; Intracellular Signaling Peptides and Proteins; Ion Transport; Iridaceae; Iridoid Glucosides; Islets of Langerhans Transplantation; Isodon; Isoflurane; Isotopes; Italy; Joint Instability; Ketamine; Kidney; Kidney Failure, Chronic; Kidney Function Tests; Kidney Neoplasms; Kinetics; Klebsiella pneumoniae; Knee Joint; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Lactate Dehydrogenase 5; Laparoscopy; Laser Therapy; Lasers, Semiconductor; Lasers, Solid-State; Laurates; Lead; Leukocyte L1 Antigen Complex; Leukocytes, Mononuclear; Light; Lipid Peroxidation; Lipopolysaccharides; Liposomes; Liver; Liver Cirrhosis; Liver Neoplasms; Liver Transplantation; Locomotion; Longitudinal Studies; Lopinavir; Lower Urinary Tract Symptoms; Lubricants; Lung; Lung Diseases, Interstitial; Lung Neoplasms; Lymphocyte Activation; Lymphocytes, Tumor-Infiltrating; Lymphoma, Mantle-Cell; Lysosomes; Macrophages; Male; Manganese Compounds; MAP Kinase Kinase 4; Mass Screening; Maternal Health; Medicine, Chinese Traditional; Melanoma, Experimental; Memantine; Membrane Glycoproteins; Membrane Proteins; Mesenchymal Stem Cell Transplantation; Metal Nanoparticles; Metalloendopeptidases; Metalloporphyrins; Methadone; Methane; Methicillin-Resistant Staphylococcus aureus; Mexico; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Mice, Nude; Mice, SCID; Mice, Transgenic; Microarray Analysis; Microbial Sensitivity Tests; Microbiota; Micronutrients; MicroRNAs; Microscopy, Confocal; Microsomes, Liver; Middle Aged; Milk; Milk, Human; Minority Groups; Mitochondria; Mitochondrial Membranes; Mitochondrial Proteins; Models, Animal; Models, Molecular; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Epidemiology; Molecular Structure; Molecular Weight; Multilocus Sequence Typing; Multimodal Imaging; Muscle Strength; Muscle, Skeletal; Muscular Diseases; Mutation; Mycobacterium tuberculosis; Myocardial Stunning; Myristates; NAD(P)H Dehydrogenase (Quinone); Nanocomposites; Nanogels; Nanoparticles; Nanotechnology; Naphthalenes; Nasal Cavity; National Health Programs; Necrosis; Needs Assessment; Neoadjuvant Therapy; Neonicotinoids; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Recurrence, Local; Neoplasm Staging; Neoplasm Transplantation; Neoplasms; Neoplastic Stem Cells; Netherlands; Neuroblastoma; Neuroprotective Agents; Neutrophils; NF-kappa B; NFATC Transcription Factors; Nicotiana; Nicotine; Nitrates; Nitrification; Nitrites; Nitro Compounds; Nitrogen; Nitrogen Dioxide; North Carolina; Nuclear Magnetic Resonance, Biomolecular; Nuclear Proteins; Nucleic Acid Hybridization; Nucleosomes; Nutrients; Obesity; Obesity, Morbid; Oceans and Seas; Oncogene Protein v-akt; Oncogenes; Oocytes; Open Reading Frames; Osteoclasts; Osteogenesis; Osteoporosis; Osteoporosis, Postmenopausal; Outpatients; Ovarian Neoplasms; Ovariectomy; Overweight; Oxazines; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxides; Oxidoreductases; Oxygen; Oxygen Inhalation Therapy; Oxygenators, Membrane; Ozone; Paclitaxel; Paenibacillus; Pain Measurement; Palliative Care; Pancreatic Neoplasms; Pandemics; Parasympathetic Nervous System; Particulate Matter; Pasteurization; Patient Preference; Patient Satisfaction; Pediatric Obesity; Permeability; Peroxiredoxins; Peroxynitrous Acid; Pharmaceutical Services; Pharmacists; Pharmacy; Phaseolus; Phenotype; Phoeniceae; Phosphates; Phosphatidylinositol 3-Kinases; Phospholipid Transfer Proteins; Phospholipids; Phosphorus; Phosphorylation; Photoperiod; Photosynthesis; Phylogeny; Physical Endurance; Physicians; Pilot Projects; Piperidines; Pituitary Adenylate Cyclase-Activating Polypeptide; Plant Extracts; Plant Leaves; Plant Proteins; Plant Roots; Plaque, Atherosclerotic; Pneumonia; Pneumonia, Viral; Point-of-Care Testing; Polyethylene Glycols; Polymers; Polysorbates; Pore Forming Cytotoxic Proteins; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Postprandial Period; Poverty; Pre-Exposure Prophylaxis; Prediabetic State; Predictive Value of Tests; Pregnancy; Pregnancy Trimester, First; Pregnancy, High-Risk; Prenatal Exposure Delayed Effects; Pressure; Prevalence; Primary Graft Dysfunction; Primary Health Care; Professional Role; Professionalism; Prognosis; Progression-Free Survival; Prolactin; Promoter Regions, Genetic; Proof of Concept Study; Proportional Hazards Models; Propylene Glycol; Prospective Studies; Prostate; Protein Binding; Protein Biosynthesis; Protein Isoforms; Protein Kinase Inhibitors; Protein Phosphatase 2; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Protein Transport; Proteoglycans; Proteome; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Proto-Oncogene Proteins c-ret; Proto-Oncogene Proteins p21(ras); Proton Pumps; Protons; Protoporphyrins; Pseudomonas aeruginosa; Pseudomonas fluorescens; Pulmonary Artery; Pulmonary Disease, Chronic Obstructive; Pulmonary Gas Exchange; Pulmonary Veins; Pyrazoles; Pyridines; Pyrimidines; Qualitative Research; Quinoxalines; Rabbits; Random Allocation; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, Histamine H3; Receptors, Immunologic; Receptors, Transferrin; Recombinant Proteins; Recurrence; Reference Values; Referral and Consultation; Regional Blood Flow; Registries; Regulon; Renal Insufficiency, Chronic; Reperfusion Injury; Repressor Proteins; Reproducibility of Results; Republic of Korea; Research Design; Resistance Training; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency; Resuscitation; Retinal Dehydrogenase; Retreatment; Retrospective Studies; Reverse Transcriptase Inhibitors; Rhinitis, Allergic; Ribosomal Proteins; Ribosomes; Risk Assessment; Risk Factors; Ritonavir; Rivers; RNA Interference; RNA-Seq; RNA, Messenger; RNA, Ribosomal, 16S; RNA, Small Interfering; Rosuvastatin Calcium; Rural Population; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Salivary Ducts; Salivary Gland Neoplasms; San Francisco; SARS-CoV-2; Satiation; Satiety Response; Schools; Schools, Pharmacy; Seasons; Seawater; Selection, Genetic; Sequence Analysis, DNA; Serine-Threonine Kinase 3; Sewage; Sheep; Sheep, Domestic; Shock, Hemorrhagic; Signal Transduction; Silver; Silymarin; Single Photon Emission Computed Tomography Computed Tomography; Sirolimus; Sirtuin 1; Skin; Skin Neoplasms; Skin Physiological Phenomena; Sleep Initiation and Maintenance Disorders; Social Class; Social Participation; Social Support; Soil; Soil Microbiology; Solutions; Somatomedins; Soot; Specimen Handling; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Spinal Fractures; Spirometry; Staphylococcus aureus; STAT1 Transcription Factor; STAT3 Transcription Factor; Streptomyces coelicolor; Stress, Psychological; Stroke; Stroke Volume; Structure-Activity Relationship; Students, Medical; Students, Pharmacy; Substance Abuse Treatment Centers; Sulfur Dioxide; Surface Properties; Surface-Active Agents; Surveys and Questionnaires; Survival Analysis; Survival Rate; Survivin; Sweden; Swine; Swine, Miniature; Sympathetic Nervous System; T-Lymphocytes, Regulatory; Talaromyces; Tandem Mass Spectrometry; tau Proteins; Telemedicine; Telomerase; Telomere; Telomere Homeostasis; Temperature; Terminally Ill; Th1 Cells; Thiamethoxam; Thiazoles; Thiophenes; Thioredoxin Reductase 1; Thrombosis; Thulium; Thyroid Cancer, Papillary; Thyroid Carcinoma, Anaplastic; Thyroid Neoplasms; Time Factors; Titanium; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; TOR Serine-Threonine Kinases; Transcription Factor AP-1; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Transcriptome; Transforming Growth Factor beta1; Transistors, Electronic; Translational Research, Biomedical; Transplantation Tolerance; Transplantation, Homologous; Transportation; Treatment Outcome; Tretinoin; Tuberculosis, Multidrug-Resistant; Tuberculosis, Pulmonary; Tubulin Modulators; Tumor Microenvironment; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha; Twins; Ultrasonic Therapy; Ultrasonography; Ultraviolet Rays; United States; Up-Regulation; Uranium; Urethra; Urinary Bladder; Urodynamics; Uromodulin; Uveitis; Vasoconstrictor Agents; Ventricular Function, Left; Vero Cells; Vesicular Transport Proteins; Viral Nonstructural Proteins; Visual Acuity; Vital Capacity; Vitamin D; Vitamin D Deficiency; Vitamin K 2; Vitamins; Volatilization; Voriconazole; Waiting Lists; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical; Whole Genome Sequencing; Wine; Wnt Signaling Pathway; Wound Healing; Wounds and Injuries; WW Domains; X-linked Nuclear Protein; X-Ray Diffraction; Xanthines; Xenograft Model Antitumor Assays; YAP-Signaling Proteins; Yogurt; Young Adult; Zebrafish; Zebrafish Proteins; Ziziphus

Prenatal exposure to ethanol results in fetal alcohol spectrum disorder (FASD), a syndrome characterised by a broad range of clinical manifestations including craniofacial dysmorphologies and neurological defects. The characterisation of the mechanisms by which ethanol exerts its teratogenic effects is difficult due to the pleiotropic nature of its actions. Different experimental model systems have been employed to investigate the aetiology of FASD. Here, I will review studies using these different model organisms that have helped to elucidate how ethanol causes the craniofacial abnormalities characteristic of FASD. In these studies, ethanol was found to impair the prechordal plate-an important embryonic signalling centre-during gastrulation and to negatively affect the induction, migration and survival of the neural crest, a cell population that generates the cartilage and most of the bones of the skull. At the cellular level, ethanol appears to inhibit Sonic hedgehog signalling, alter levels of retionoic acid activity, trigger a Ca(2+)-CamKII-dependent pathway that antagonises WNT signalling, affect cytoskeletal dynamics and increase oxidative stress. Embryos of the domestic chick Gallus gallus domesticus have played a central role in developing a working model for the effects of ethanol on craniofacial development because they are easily accessible and because key steps in craniofacial development are particularly well established in the avian embryo. I will finish this review by highlighting some potential future avenues of fetal alcohol research.

Topics: Abnormalities, Drug-Induced; Animals; Calcium Signaling; Chick Embryo; Craniofacial Abnormalities; Disease Models, Animal; Embryo, Mammalian; Embryo, Nonmammalian; Endoderm; Ethanol; Face; Fetal Alcohol Spectrum Disorders; Gastrula; Genetic Predisposition to Disease; Hedgehog Proteins; Holoprosencephaly; Humans; Maxillofacial Development; Neural Crest; Signal Transduction; Skull; Species Specificity; Tretinoin; Wnt Signaling Pathway

Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity.

Topics: Adaptive Immunity; Animals; Cell Differentiation; Clinical Trials as Topic; Dietary Supplements; Disease Models, Animal; Epithelial Cells; Humans; Immune Tolerance; Immunity, Cellular; Lymphocytes; Organogenesis; T-Lymphocytes; Th1 Cells; Th17 Cells; Th2 Cells; Thymus Gland; Tretinoin; Vitamin A Deficiency

Acute promyelocytic leukemia (APL) is one of the well-characterized subtypes of acute myeloid leukemia (AML). The essential drugs used in the treatment strategy for APL include all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), which are both pioneer molecular-targeting agents. They were initially administered to patients based on the therapeutic experience of traditional Chinese medicine, and their marked effectiveness has been demonstrated. Subsequently, the molecular mechanisms of these drugs, as well as the molecular pathogenesis of APL, have been elucidated, whereby the chimeric gene product PML-RARα induces epigenetic changes and transcription repression. This review summarizes the findings of previous studies related to the in vitro and in vivo function of PML-RARα and the effects of ATRA and ATO on PML-RARα and APL cells. These findings are very important, because the concept of epigenetic modulation in oncogenesis and their application as molecular targets in APL therapy have now been accepted in other types of leukemia, as well as for other malignancies.

Topics: Animals; Antineoplastic Agents; Arsenic Trioxide; Arsenicals; Disease Models, Animal; Epigenomics; Humans; Leukemia, Promyelocytic, Acute; Medicine, Chinese Traditional; Mice; Molecular Targeted Therapy; Oncogene Proteins, Fusion; Oxides; Transcription, Genetic; Tretinoin

In this review, we summarize recent advances in understanding vitamin A-dependent regulation of sex-specific differences in metabolic diseases, inflammation, and certain cancers. We focus on the characterization of the aldehyde dehydrogenase-1 family of enzymes (ALDH1A1, ALDH1A2, ALDH1A3) that catalyze conversion of retinaldehyde to retinoic acid. Additionally, we propose a "horizontal transfer of signaling" from estrogen to retinoids through the action of ALDH1A1. Although estrogen does not directly influence expression of Aldh1a1, it has the ability to suppress Aldh1a2 and Aldh1a3, thereby establishing a female-specific mechanism for retinoic acid generation in target tissues. ALDH1A1 regulates adipogenesis, abdominal fat formation, glucose tolerance, and suppression of thermogenesis in adipocytes; in B cells, ALDH1A1 plays a protective role by inducing oncogene suppressors Rara and Pparg. Considering the conflicting responses of Aldh1a1 in a multitude of physiological processes, only tissue-specific regulation of Aldh1a1 can result in therapeutic effects. We have shown through successful implantation of tissue-specific Aldh1a1-/- preadipocytes that thermogenesis can be induced in wild-type adipose tissues to resolve diet-induced visceral obesity in females. We will briefly discuss the emerging role of ALDH1A1 in multiple myeloma, the regulation of reproduction, and immune responses, and conclude by discussing the role of ALDH1A1 in future therapeutic applications.

Topics: Adipocytes; Adipogenesis; Adipose Tissue, White; Aldehyde Dehydrogenase; Aldehyde Dehydrogenase 1 Family; Animals; Body Fat Distribution; Chronic Disease; Cytokines; Diet; Disease Models, Animal; Estradiol; Female; Humans; Obesity; Polycystic Ovary Syndrome; Retinal Dehydrogenase; Retinaldehyde; Risk Factors; Sex Factors; Thermogenesis; Tretinoin

Acute promyelocytic leukemia (APL) is a distinct subset of acute myeloid leukemia (AML) associated with peculiar biologic and clinical features and requiring specific management. At the genetic level, APL is featured by a unique chromosome translocation t(15;17) which results in the PML-RARα gene fusion and chimeric protein. APL is the first example of differentiation therapy targeted to a defined genetic target i.e. PML-RARα. PML-RARα behaves as an altered retinoic acid receptor with an ability of transmitting oncogenic signaling leading to accumulation of undifferentiated promyelocytes. All-trans-retinoic acid (ATRA) induces disease remission in APL patients by triggering terminal differentiation of leukemic promyelocytes. More recently, arsenic trioxide (ATO) has been shown to contribute degradation of the PML-RARα oncoprotein through bonding the PML moiety and has shown excellent synergism with ATRA in clinical trials. Elucidating the oncogenic signaling of PML-RARα through various transcription factors and the study of APL mouse models have greatly helped to understand the molecular pathogenesis of APL. However, the precise molecular mechanism by which t(15;17) is formed and initiates leukemia remains unknown. While transforming oncogenic potential of PML-RARα has been described extensively, the mechanistic events important for the formation of t(15;17) have been taken from the model of Therapy-related APL (t-APL).

Topics: Animals; Antineoplastic Agents; Arsenic Trioxide; Arsenicals; Cell Differentiation; Cell Transformation, Neoplastic; Chromosomes, Human, Pair 15; Chromosomes, Human, Pair 17; Clinical Trials as Topic; Disease Models, Animal; DNA End-Joining Repair; Drug Synergism; Granulocyte Precursor Cells; Humans; Leukemia, Promyelocytic, Acute; Mice; Molecular Targeted Therapy; Neoplasm Proteins; Neoplasms, Second Primary; Neoplastic Stem Cells; Oncogene Proteins, Fusion; Oxides; Signal Transduction; Topoisomerase II Inhibitors; Translocation, Genetic; Tretinoin

Alopecia areata (AA) is a cell-mediated autoimmune disease that targets actively growing hair follicles in mammals, including humans and mice. Development of the C3H/HeJ spontaneous mouse model AA nearly 20 years ago provided a much needed tool to test the hypotheses and ultimately serve as a preclinical model for drug testing. Discoveries in both human AA patients and the mouse model supported each other and lead to discoveries on the incredibly complex genetic basis of this disease. The discovery that A/J, MRL/MpJ, SJL/J, and SWR/J strains also develop AA now allows genome-wide association mapping studies to expand the list of genes underlying this disease. Potential new targets for unraveling the pathogenesis of AA include the role of retinoic acid metabolism in the severity of disease and hair shaft proteins that may be either the inciting antigen or ultimate target of the immune reaction leading to breakage of the shaft causing clinical alopecia. Comparing these model systems with human and mouse clinical disease, for both discovery and validation of the discoveries, continues to resolve the complex questions surrounding AA.

Topics: Alopecia Areata; Animals; Disease Models, Animal; Genetic Predisposition to Disease; Genome-Wide Association Study; Mice; Mice, Inbred C3H; Tretinoin

Retinoic acid or vitamin A is important for an extensive range of biological processes, including immunomodulatory functions, however, its role in gastrointestinal parasite infections is not yet clear. Despite this, parasite infected individuals are often supplemented with vitamin A, given the co-localised prevalence of parasitic infections and vitamin deficiencies. Therefore, it is important to understand the impact of this vitamin on the immune responses to gastrointestinal parasites. Here, we review data regarding the role of retinoic acid signalling in mouse models of intestinal nematode infection, with a view to understanding better the practice of giving vitamin A supplements to worm-infected people.

Topics: Animals; Disease Models, Animal; Helminthiasis; Intestinal Diseases; Intestinal Diseases, Parasitic; Mice; Nematode Infections; Signal Transduction; Tretinoin

During cardiac looping the heart tube elongates by addition of progenitor cells from adjacent pharyngeal mesoderm to the arterial and venous poles. This cell population, termed the second heart field, was first identified ten years ago and many studies in the intervening decade have refined our understanding of how heart tube elongation takes place and identified signaling pathways that regulate proliferation and differentiation during progressive contribution of second heart field cells to the embryonic heart. It has also become apparent that defective second heart field development results in common congenital heart anomalies affecting both the conotruncal region and venous pole of the heart, including atrial and atrioventricular septal defects. In this review we focus on a series of recent papers that have identified new regulators of second heart field development, in particular the retinoic acid signaling pathway and HOX, SIX and EYA transcription factors. We also discuss new findings concerning the regulation of fibroblast growth factor signaling during second heart field deployment and studies that have implicated FGF10 and FGF3 in outflow tract development in addition to FGF8. Second heart field derived parts of the heart share common progenitor cells in pharyngeal mesoderm with craniofacial skeletal muscles and recent findings from xenopus, zebrafish and the protochordate Ciona intestinalis provide insights into the evolution of the second heart field during vertebrate radiation.

Topics: Animals; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Fibroblast Growth Factors; Fibroblasts; Heart; Heart Defects, Congenital; Mesoderm; Mice; Myocytes, Cardiac; Organogenesis; Signal Transduction; Transcription Factors; Tretinoin

Topics: Animals; Antineoplastic Agents; Benzamides; Dasatinib; Disease Models, Animal; History, 19th Century; Humans; Imatinib Mesylate; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Philadelphia Chromosome; Piperazines; Pyrimidines; Thiazoles; Tretinoin

Congenital diaphragmatic hernia (CDH) is a common cause of severe neonatal respiratory distress. Mortality and morbidity are determined by the amount of pulmonary hypoplasia (PH) that occurs and by the development of therapy-resistant pulmonary hypertension. The pathogenesis and aetiology of CDH and its associated anomalies are still largely unknown despite all research efforts. The pathogenesis of CDH is based on an assumption linking herniation of abdominal viscera into the thorax with compression of the developing lung. PH, however, can also result from reduced distension of the developing lung secondary to impaired fetal breathing movements. Our understanding of CDH has also been aided by basic research with the use of dietary, teratogen-induced, and knockout models of CDH. These studies indicate that lung hypoplasia may involve disturbances of mitogenic signalling pathways fundamental to embryonic lung development. Recent data reveal the role of disruption of a retinoid-signalling pathway in the pathogenesis of CDH. Although multifactorial inheritance may best explain most cases of CDH in humans, much has been learned about the genetic factors that play a role in the development of CDH by studies of patients with CDH caused by specific genetic syndromes and chromosome anomalies. More research is warranted to improve our understanding of normal and abnormal lung development in relation to CDH. Such investigations will help in the design of new treatment strategies to improve the natural course or even to prevent this anomaly.

Topics: Abnormalities, Multiple; Animals; Disease Models, Animal; Female; Genetic Association Studies; Gestational Age; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Humans; Infant, Newborn; Lung; Mice; Mice, Knockout; Persistent Fetal Circulation Syndrome; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Distress Syndrome, Newborn; Risk Factors; Tretinoin; Vitamin A

Carotenoids play a pivotal role in prevention of many degenerative diseases mediated by oxidative stress including neurodegenerative diseases like Alzheimer's Disease (AD). The involvement of retinoids in physiology, AD pathology and their therapeutic role in vitro and in vivo has been extensively studied. This review focuses on the role of carotenoids like retinoic acid (RA), all trans retinoic acid (ATRA), lycopene and β-carotene in prevention of AD symptoms primarily through inhibition of amyloid beta (Aβ) formation, deposition and fibril formation either by reducing the levels of p35 or inhibiting corresponding enzymes. The role of antioxidant micronutrients in prevention or delaying of AD symptoms has been included. This study emphasizes the dietary supplementation of carotenoids to combat AD and warrants further studies on animal models to unravel their mechanism of neuroprotection.

Topics: Alzheimer Disease; Animals; Antioxidants; Carotenoids; Disease Models, Animal; Excitatory Amino Acid Transporter 2; Humans; Lycopene; Micronutrients; Neuroprotective Agents; Retinoids; Tretinoin; Vitamin A

Tbx1 is a member of the Tbox family of binding domain transcription factors. TBX1 maps within the region of 22q11 deleted in humans with DiGeorge or velocardiofacial syndrome. Mice haploinsufficient for Tbx1 have phenotypes that recapitulate major features of the syndrome, notably abnormal growth and remodelling of the pharyngeal arch arteries. The Tbx1 haploinsufficiency phenotype is modified by genetic background and by mutations in putative downstream targets. Homozygous null mutations of Tbx1 have more severe defects including failure of outflow tract septation, and absence of the caudal pharyngeal arches. Tbx1 is a transcriptional activator, and loss of this activity has been linked to alterations in the expression of various genes involved in cardiovascular morphogenesis. In particular, Fgf and retinoic acid signalling are dysregulated in Tbx1 mutants. This article summarises the tissue specific and temporal requirements for Tbx1, and attempts to synthesis what is know about the developmental pathways under its control.

Topics: Animals; Branchial Region; DiGeorge Syndrome; Disease Models, Animal; Gene Deletion; Heart; Heart Defects, Congenital; Mice; Mutation; Phenotype; Signal Transduction; Syndrome; T-Box Domain Proteins; Tretinoin

Reduction of posterior capsule opacification (PCO) after cataract surgery has been achieved since the general acceptance of posterior chamber intraocular lens implantation 30 years ago. Attention to surgical technique on the one hand and changes in lens design and materials on the other have synergistically reduced the incidence of PCO to less than 5% at 5 years. But lens epithelial cells still proliferate and pharmacological prevention has been largely unsuccessful so far. Any agent must be toxic to these lens epithelial cells without being toxic to the corneal endothelium. This review looks at many substances that have been tried and a few that have been partly successful without yet entering clinical practice. Possibilities for future clinical research are canvassed.

Topics: Animals; Cataract Extraction; Corneal Opacity; Dexamethasone; Diclofenac; Disease Models, Animal; Humans; Lens Capsule, Crystalline; Lens Implantation, Intraocular; Postoperative Complications; Tretinoin

Current models of affective disorders implicate alterations in norepinephrine, serotonin, dopamine, and CRF/cortisol; however treatments targeted at these neurotransmitters or hormones have led to imperfect resolution of symptoms, suggesting that the neurobiology of affective disorders is incompletely understood. Until now retinoids have not been considered as possible contributors to affective disorders. Retinoids represent a family of compounds derived from vitamin A that perform a large number of functions, many via the vitamin A product, retinoic acid. This signaling molecule binds to specific retinoic acid receptors in the brain which, like the glucocorticoid and thyroid hormone receptors, are part of the nuclear receptor superfamily and regulate gene transcription. Research in the field of retinoic acid in the CNS has focused on the developing brain, in part stimulated by the observation that isotretinoin (13-cis retinoic acid), an isomer of retinoic acid used in the treatment of acne, is highly teratogenic for the CNS. More recent work has suggested that retinoic acid may influence the adult brain; animal studies indicated that the administration of isotretinoin is associated with alterations in behavior as well as inhibition of neurogenesis in the hippocampus. Clinical evidence for an association between retinoids and depression includes case reports in the literature, studies of health care databases, and other sources. A preliminary PET study in human subjects showed that isotretinoin was associated with a decrease in orbitofrontal metabolism. Several studies have shown that the molecular components required for retinoic acid signaling are expressed in the adult brain; the overlap of brain areas implicated in retinoic acid function and stress and depression suggest that retinoids could play a role in affective disorders. This report reviews the evidence in this area and describes several systems that may be targets of retinoic acid and which contribute to the pathophysiology of depression.

Topics: Adult; Animals; Brain; Corpus Striatum; Depressive Disorder, Major; Disease Models, Animal; Hippocampus; Humans; Isotretinoin; Mice; Mood Disorders; Neurotransmitter Agents; Prefrontal Cortex; Retrospective Studies; Signal Transduction; Suicide; Tretinoin

Leukemia is a group of heterozygous diseases of hematopoietic stem/progenitor cells that involves dynamic change in the genome. Dissection of genetic abnormalities critical to leukemia initiation provides insights into the elusive leukemogenesis, identifies distinct subsets of leukemia and predicts prognosis individually, and can also provide rational therapeutic targets for curative approaches. The past three decades have seen tremendous advances in the analysis of genotype-phenotype connection of leukemia, and in the identification of molecular biomarkers for leukemia subtypes. Intriguingly, differentiation therapy, targeted therapy and chemotherapy have turned several subtypes of leukemia from highly fatal to highly curable. The use of all-trans retinoic acid and arsenic trioxide, which trigger degradation of PML-RARalpha, the causative fusion protein generated by t (15;17) translocation in acute promyelocytic leukemia (APL), has led to a dramatic improvement of APL clinical outcome. Imatinib mesylate/ Gleevec/STI571, which inhibits the tyrosine kinase activity of BCR-ABL oncoprotein, has now become the new gold standard for the treatment of chronic myeloid leukemia. Optimal use of chemotherapeutic agents together with a stringent application of prognostic factors for risk-directed therapy in clinical trials has resulted in a steady improvement in the treatment outcome of acute lymphoblastic leukemia. Hence, the pace of progress extrapolates to a prediction of leukemia control in the twenty-first century.

Topics: Animals; Antineoplastic Agents; Arsenic Trioxide; Arsenicals; Benzamides; Disease Models, Animal; Humans; Imatinib Mesylate; Leukemia; Oxides; Piperazines; Pyrimidines; Tretinoin

To explore the role of retinoic acid (RA) in the liver, we developed transgenic mice expressing RA receptor a-dominant negative form (RARE) in hepatocytes using albumin promoter and enhancer. The RARE m ice developed microvesicular steatosis andspotty focal necrosis. Mitochondrial beta-oxidation activity of fatty acids and related enzymes were down-regulated, while peroxisomal beta-oxidation and related enzymes were up-regulated. Expression of cytochrome p4504a10, cytochrome p4504a12, and cytochrome p4504a14 was increased. Formation of H2O2 and 8-OHdG was increased. With age, these mice developed liver tumor. Feeding on a high-RA diet reversed histological and biochemical abnormalities and inhibited the occurrence of liver tumors. These results suggest that hepatic loss of RA function leads to the development of steatohepatitis and liver tumors.

Topics: Animals; Cytochrome P-450 Enzyme System; Disease Models, Animal; Fatty Acids; Fatty Liver; Hepatocytes; Lipid Metabolism; Liver Neoplasms; Mice; Mice, Transgenic; Oxidative Stress; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Tretinoin

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of proteins. The role of PPARs in regulating the transcription of genes involved in glucose and lipid metabolism has been extensively characterized. Interestingly, PPARs have also been demonstrated to mediate inflammatory responses. Microglia participate in pathology associated with multiple sclerosis (MS). Upon activation, microglia produce molecules including NO and TNF-alpha that can be toxic to CNS cells including myelin-producing oligodendrocytes and neurons, which are compromised in the course of MS. Previously, we and others demonstrated that PPAR-gamma agonists including 15d-PGJ(2) are effective in the treatment of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. PPAR-gamma modulation of EAE may occur, at least in part, by inhibition of microglial cell activation. Here, we indicate that 15d-PGJ(2) is a more potent inhibitor of microglial activation than thiazolidinediones, which are currently used to treat diabetes. Furthermore, 15d-PGJ(2) acts cooperatively with 9-cis retinoic acid, the ligand for the retinoid X receptor (RXR), in inhibiting microglial cell activation. This suggests that 15d-PGJ(2) and 9-cis RA inhibit cell activation through the formation of PPAR-gamma/RXR heterodimers. Interestingly, PGA(2), which like 15d-PGJ(2) is a cyclopentenone prostaglandin, but which unlike 15d-PGJ(2) does not bind PPAR-gamma, is a potent inhibitor of microglial cell activation. Collectively, these studies suggest that 15d-PGJ(2) inhibits microglial cell activation by PPAR-gamma-dependent as well as PPAR-gamma-independent mechanisms. The studies further suggest that the PPAR-gamma agonist 15d-PGJ(2) in combination with retinoids may be effective in the treatment of MS.

Topics: Animals; Disease Models, Animal; Humans; Microglia; Models, Biological; Multiple Sclerosis; Neurons; PPAR gamma; Prostaglandin D2; Tretinoin

Recent data suggest that exogenous retinoic acid (RA), the biologically active derivative of vitamin A, can induce alveolar regeneration in a rat model of experimental emphysema. Here, we describe a mouse model of disrupted alveolar development using dexamethasone administered postnatally. We show that the effects of dexamethasone are concentration dependent, dose dependent, long lasting and result in a severe loss of alveolar surface area. When RA is administered to these animals as adults, lung architecture and the surface area per unit of body weight are completely restored to normal. This remarkable effect may be because RA is required during normal alveolar development and administering RA re-awakens gene cascades used during development. We provide evidence that RA is required during alveologenesis in the mouse by showing that the levels of the retinoid binding proteins, the RA receptors and two RA synthesizing enzymes peak postnatally. Furthermore, an inhibitor of RA synthesis, disulphiram, disrupts alveologenesis. We also show that RA is required throughout life for the maintenance of lung alveoli because when rats are deprived of dietary retinol they lose alveoli and show the features of emphysema. Alveolar regeneration with RA may therefore be an important novel therapeutic approach to the treatment of respiratory diseases characterized by a reduced gas-exchanging surface area such as bronchopulmonary dysplasia and emphysema for which there are currently no treatments.

Topics: Animals; Dexamethasone; Disease Models, Animal; Dose-Response Relationship, Drug; Emphysema; Humans; Mice; Morphogenesis; Pulmonary Alveoli; Receptors, Retinoic Acid; Regeneration; Signal Transduction; Tretinoin

Translocations involving a variety of fusion partners, such as promyelocytic leukemia gene, promyelocytic leukemia zinc finger, nucleophosmin, nuclear matrix protein, and signal transducer and activator of transcription protein 5B, with the retinoic acid receptor alpha gene are commonly associated with development of acute promyelocytic leukemia. Through the development of transgenic mouse models, some retinoic acid receptor alpha translocation fusion proteins have been shown to be capable of initiating acute promyelocytic leukemia development, and dictate the leukemias' responsiveness to retinoic acid. Transgenic mouse models also have identified the influence of reciprocal translocation fusion proteins on acute promyelocytic leukemia development, and have demonstrated that additional mutations can contribute to the development of acute promyelocytic leukemia. In this review, the authors summarize current mouse models of acute promyelocytic leukemia and describe current knowledge about additional genetic alterations that occur during development of acute promyelocytic leukemia in the mouse.

Topics: Animals; Antineoplastic Agents; Arsenic; Chromosome Deletion; Disease Models, Animal; Leukemia, Promyelocytic, Acute; Mice; Models, Biological; Mutation; Neoplasm Proteins; Oncogene Proteins, Fusion; Tretinoin

Acute promyelocytic leukemia (APL) is an interesting model in cancer research, because it can respond to the differentiation/apoptosis induction therapy using all-trans retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)). Over the past 5 years, it has been well demonstrated that As(2)O(3) induces a high complete remission (CR) rate in both primary and relapsed APL patients (around 85 to 90%). The side effects are mild to moderate in relapsed patients, while severe hepatic lesions have been found in some primary cases. After CR obtained in relapsed patients, chemotherapy in combination with As(2)O(3) as post-remission therapy has given better survival than those treated with As(2)O(3) alone. The effect of As(2)O(3) has been shown to be related to the expression of APL-specific PML-RARalpha oncoprotein, and there is a synergistic effect between As(2)O(3) and ATRA in an APL mouse model. Cell biology studies have revealed that As(2)O(3) exerts dose-dependent dual effects on APL cells. Apoptosis is evident when cells are treated with 0.5 approximately 2.0 microM of As(2)O(3) while partial differentiation is observed using low concentrations (0.1 approximately 0.5 microM) of the drug. The apoptosis-inducing effect is associated with the collapse of mitochondrial transmembrane potentials in a thiol-dependent manner, whereas the mechanisms underlying APL cell differentiation induced by low dose arsenic remain to be explored. Interestingly, As(2)O(3) over a wide range of concentration (0.1 approximately 2.0 microM) induces degradation of a key leukemogenic protein, PML-RARalpha, as well as the wild-type PML, thus setting up a good example of targeting therapy for human cancers.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Arsenic Trioxide; Arsenicals; Cell Differentiation; Disease Models, Animal; Drug Synergism; Humans; Leukemia, Promyelocytic, Acute; Mice; Mitochondria; Neoplasm Proteins; Nuclear Proteins; Oncogene Proteins, Fusion; Oxides; Promyelocytic Leukemia Protein; Remission Induction; Survival Rate; Transcription Factors; Tretinoin; Tumor Suppressor Proteins

Topics: Animals; Disease Models, Animal; Humans; Keratolytic Agents; Molecular Structure; Pancreatic Elastase; Pulmonary Alveoli; Pulmonary Emphysema; Respiratory Function Tests; Tretinoin; Vitamin A

Topics: Airway Obstruction; Animals; Bronchiolitis; Collagen; Collagenases; Disease Models, Animal; Elastin; Humans; Prognosis; Pulmonary Alveoli; Pulmonary Emphysema; Tretinoin

Acute promyelocytic leukemia (APL) is the most potentially curable type of acute myeloid leukemia. It is characterized by the chromosomal translocation t(15;17), which results in the fusion gene PML-RAR-alpha. The introduction of all-trans- retinoic acid (ATRA) was a major advance in treatment of this disease. This agent induces terminal differentiation of malignant myeloid cells to mature neutrophils, and its side effects are usually well tolerated in children. ATRA does not eradicate the malignant myeloid clone in APL and, eventually, resistance develops. Arsenic trioxide induces nonterminal differentiation of malignant promyelocytes and promotes apoptosis. APL patients treated with ATRA or arsenic trioxide have rapid resolution of their coagulopathy. Because both of these drugs are well tolerated in children and their synergy has been shown in animal models, the possibility of combining ATRA and arsenic trioxide in front-line therapy for children with APL is being considered.

Topics: Animals; Antineoplastic Agents; Arsenic Trioxide; Arsenicals; Cell Differentiation; Child; Disease Models, Animal; Drug Therapy, Combination; Humans; Leukemia, Promyelocytic, Acute; Oxides; Tretinoin

Schizophrenia is thought to be a disease of early development that ultimately affects forebrain neurons and circuits. There may be a relationship between disrupted forebrain development; malformations of the limb, face, and heart; and signaling via the steroid-like hormone retinoic acid (RA) in some schizophrenic patients. The limbs, face, heart, and forebrain all develop from sites where neural crest-derived, RA-producing mesenchyme contributes to induction and differentiation of adjacent epithelia. Induction between neural crest-derived, RA-producing mesenchyme, the anterior neural tube, and the anterior surface epithelium of the embryo guides regional differentiation and pathway formation during forebrain development. Furthermore, there are at least two mouse mutations--in the Pax-6 and Gli-3 genes--that cause peripheral malformations and specifically disrupt neural crest mediated, RA-dependent induction and differentiation in the forebrain. These observations suggest that induction might provide a common target for genes that alter morphogenesis of peripheral structures, disrupt RA-signaling, and compromise forebrain development. In the forebrain, some of these disruptions might influence the numbers or cellular properties of neurons and circuits. Such changes might be reflected in the aberrant forebrain function that characterizes schizophrenia.

Topics: Animals; Disease Models, Animal; Gene Expression Regulation; Genetic Predisposition to Disease; Mice; Mice, Inbred Strains; Phenotype; Point Mutation; Prosencephalon; Schizophrenia; Tretinoin

Differentiation-inducing therapy by all-trans retinoic acid (RA) is now a standard therapy in patients with acute promyelocytic leukemia (APL). Nearly all patients achieve complete remission by the treatment of all-trans RA, however, clinical remissions are usually of brief duration, and these patients often develop RA-resistant disease. The mechanisms of RA-resistance in APL cells are poorly understood and most clinical approaches have not been successful in overcoming RA-resistance. We have recently established a novel APL cell line (UF-1) with RA-resistant features. In addition, we have established human GM-CSF-producing transgenic (hGMTg) SCID mice system. UF-1 cells were inoculated either intraperitoneally or subcutaneously into hGMTg SCID mice and made the first RA-resistant murine APL model. These RA-resistant APL model systems in vitro and in vivo may be useful for investigating the molecular studies on the block of leukemic cell differentiation and as means to investigate the mechanisms of RA-resistance. Moreover, this murine model system will be important for developing novel therapeutic strategies in RA-resistant APL.

Topics: Animals; Antineoplastic Agents; Disease Models, Animal; Drug Resistance, Neoplasm; Humans; Leukemia, Promyelocytic, Acute; Mice; Mice, SCID; Tretinoin

Topics: Animals; Antineoplastic Agents; Disease Models, Animal; Humans; Leukemia, Promyelocytic, Acute; Tretinoin

Acute promyelocytic leukemia (APL) is characterized by the expansion of malignant myeloid cells blocked at the promyelocytic stage of hemopoietic development, and is associated with reciprocal chromosomal translocations always involving the retinoic acid receptor alpha (RARalpha) gene on chromosome 17. As a consequence of the translocation RARalpha variably fuses to the PML, PLZF, NPM and NUMA genes (X genes), leading to the generation of RARalpha-X and X-RARalpha fusion genes. The aberrant chimeric proteins encoded by these genes may exert a crucial role in leukemogenesis. Retinoic acid (RA), a metabolite of vitamin A, can overcome the block of maturation at the promyelocytic stage and induce the malignant cells to terminally mature into granulocytes resulting in complete albeit transient disease remission. APL has become, for this reason, the paradigm for 'cancer differentiation therapy'. Furthermore, APL associated with translocation between the RARalpha and the PLZF genes (PLZF-RARalpha) shows a distinctly worse prognosis with poor response to chemotherapy and little or no response to treatment with RA, thus defining a new APL syndrome. Here we will focus our attention on the recent progresses made in defining the molecular mechanisms underlying the pathogenesis of this paradigmatic disease in vivo in the mouse. We will review the critical contribution of mouse modeling in unraveling the transcriptional basis for the differential response to RA in APL. We will also discuss how this new understanding has allowed to propose, develop and test in these murine leukemia models as well as in human APL patients novel therapeutic strategies.

Topics: Animals; Antineoplastic Agents; Disease Models, Animal; Humans; Leukemia, Promyelocytic, Acute; Mice; Neoplasm Proteins; Oncogene Proteins, Fusion; Tretinoin

Neural tube defects (NTDs) are some of the most common human malformations. The vast majority of NTDs can be prevented by the administration of folic acid; however, to date there has been no effective treatment of folic acid-resistant NTDs. A recent paper has confirmed an earlier report that the administration of inositol to the curly tail mutant mouse, which is a model of folate-resistant NTDs, can cure such defects. The molecular pathway by which this is achieved is thought to occur by the up-regulation of the retinoic acid receptor beta in the underlying hindgut endoderm, correcting a proliferation defect. However, alternative explanations also may account for NTDs.

Topics: Animals; Disease Models, Animal; Drug Resistance; Female; Folic Acid; Humans; Inositol; Mice; Mice, Mutant Strains; Neural Tube Defects; Pregnancy; Receptors, Retinoic Acid; Tretinoin

Normal anterior segment embryogenesis is summarized followed by a review of syndromes of spontaneous and inherited conditions of abnormal development in humans and animals. The study of teratogen-induced malformations in animal models has provided valuable information about critical periods during gestation for the initiation of anterior segment dysgenesis. Although the major developmental events leading to iridocorneal angle formation occur during the third trimester, it appears that embryonic insult much earlier in human gestation (during the first three to five weeks post fertilization) can induce an abnormal sequence of events leading to anterior segment dysgenesis.

Topics: Abnormalities, Drug-Induced; Animals; Anterior Eye Segment; Cataract; Disease Models, Animal; Ethanol; Female; Glaucoma; Humans; Mice; Mice, Inbred C57BL; Microscopy, Electron, Scanning; Ochratoxins; Pregnancy; Syndrome; Teratogens; Trabecular Meshwork; Tretinoin

Middle East Respiratory Syndrome (MERS) is a novel respiratory illness firstly reported in Saudi Arabia in 2012. It is caused by a new corona virus, called MERS corona virus (MERS-CoV). Most people who have MERS-CoV infection developed severe acute respiratory illness.. This work is done to determine the clinical characteristics and the outcome of intensive care unit (ICU) admitted patients with confirmed MERS-CoV infection.. This study included 32 laboratory confirmed MERS corona virus infected patients who were admitted into ICU. It included 20 (62.50%) males and 12 (37.50%) females. The mean age was 43.99 ± 13.03 years. Diagnosis was done by real-time reverse transcription polymerase chain reaction (rRT-PCR) test for corona virus on throat swab, sputum, tracheal aspirate, or bronchoalveolar lavage specimens. Clinical characteristics, co-morbidities and outcome were reported for all subjects.. Most MERS corona patients present with fever, cough, dyspnea, sore throat, runny nose and sputum. The presence of abdominal symptoms may indicate bad prognosis. Prolonged duration of symptoms before patients' hospitalization, prolonged duration of mechanical ventilation and hospital stay, bilateral radiological pulmonary infiltrates, and hypoxemic respiratory failure were found to be strong predictors of mortality in such patients. Also, old age, current smoking, smoking severity, presence of associated co-morbidities like obesity, diabetes mellitus, chronic heart diseases, COPD, malignancy, renal failure, renal transplantation and liver cirrhosis are associated with a poor outcome of ICU admitted MERS corona virus infected patients.. Plasma HO-1, ferritin, p21, and NQO1 were all elevated at baseline in CKD participants. Plasma HO-1 and urine NQO1 levels each inversely correlated with eGFR (. SnPP can be safely administered and, after its injection, the resulting changes in plasma HO-1, NQO1, ferritin, and p21 concentrations can provide information as to antioxidant gene responsiveness/reserves in subjects with and without kidney disease.. A Study with RBT-1, in Healthy Volunteers and Subjects with Stage 3-4 Chronic Kidney Disease, NCT0363002 and NCT03893799.. HFNC did not significantly modify work of breathing in healthy subjects. However, a significant reduction in the minute volume was achieved, capillary [Formula: see text] remaining constant, which suggests a reduction in dead-space ventilation with flows > 20 L/min. (ClinicalTrials.gov registration NCT02495675).. 3 组患者手术时间、术中显性失血量及术后 1 周血红蛋白下降量比较差异均无统计学意义（. 对于肥胖和超重的膝关节单间室骨关节炎患者，采用 UKA 术后可获满意短中期疗效，远期疗效尚需进一步随访观察。.. Decreased muscle strength was identified at both time points in patients with hEDS/HSD. The evolution of most muscle strength parameters over time did not significantly differ between groups. Future studies should focus on the effectiveness of different types of muscle training strategies in hEDS/HSD patients.. These findings support previous adverse findings of e-cigarette exposure on neurodevelopment in a mouse model and provide substantial evidence of persistent adverse behavioral and neuroimmunological consequences to adult offspring following maternal e-cigarette exposure during pregnancy. https://doi.org/10.1289/EHP6067.. This RCT directly compares a neoadjuvant chemotherapy regimen with a standard CROSS regimen in terms of overall survival for patients with locally advanced ESCC. The results of this RCT will provide an answer for the controversy regarding the survival benefits between the two treatment strategies.. NCT04138212, date of registration: October 24, 2019.. Results of current investigation indicated that milk type and post fermentation cooling patterns had a pronounced effect on antioxidant characteristics, fatty acid profile, lipid oxidation and textural characteristics of yoghurt. Buffalo milk based yoghurt had more fat, protein, higher antioxidant capacity and vitamin content. Antioxidant and sensory characteristics of T. If milk is exposed to excessive amounts of light, Vitamins B. The two concentration of ZnO nanoparticles in the ambient air produced two different outcomes. The lower concentration resulted in significant increases in Zn content of the liver while the higher concentration significantly increased Zn in the lungs (p < 0.05). Additionally, at the lower concentration, Zn content was found to be lower in brain tissue (p < 0.05). Using TEM/EDX we detected ZnO nanoparticles inside the cells in the lungs, kidney and liver. Inhaling ZnO NP at the higher concentration increased the levels of mRNA of the following genes in the lungs: Mt2 (2.56 fold), Slc30a1 (1.52 fold) and Slc30a5 (2.34 fold). At the lower ZnO nanoparticle concentration, only Slc30a7 mRNA levels in the lungs were up (1.74 fold). Thus the two air concentrations of ZnO nanoparticles produced distinct effects on the expression of the Zn-homeostasis related genes.. Until adverse health effects of ZnO nanoparticles deposited in organs such as lungs are further investigated and/or ruled out, the exposure to ZnO nanoparticles in aerosols should be avoided or minimised.

Topics: A549 Cells; Acetylmuramyl-Alanyl-Isoglutamine; Acinetobacter baumannii; Acute Lung Injury; Adaptor Proteins, Signal Transducing; Adenine; Adenocarcinoma; Adipogenesis; Administration, Cutaneous; Administration, Ophthalmic; Adolescent; Adsorption; Adult; Aeromonas hydrophila; Aerosols; Aged; Aged, 80 and over; Aging; Agriculture; Air Pollutants; Air Pollution; Airway Remodeling; Alanine Transaminase; Albuminuria; Aldehyde Dehydrogenase 1 Family; Algorithms; AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; Alzheimer Disease; Amino Acid Sequence; Ammonia; Ammonium Compounds; Anaerobiosis; Anesthetics, Dissociative; Anesthetics, Inhalation; Animals; Anti-Bacterial Agents; Anti-HIV Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal, Humanized; Antifungal Agents; Antigens, Bacterial; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Antitubercular Agents; Antiviral Agents; Apolipoproteins E; Apoptosis; Arabidopsis; Arabidopsis Proteins; Arsenic; Arthritis, Rheumatoid; Asthma; Atherosclerosis; ATP-Dependent Proteases; Attitude of Health Personnel; Australia; Austria; Autophagy; Axitinib; Bacteria; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacterial Toxins; Bacterial Typing Techniques; Bariatric Surgery; Base Composition; Bayes Theorem; Benzoxazoles; Benzylamines; beta Catenin; Betacoronavirus; Betula; Binding Sites; Biological Availability; Biological Oxygen Demand Analysis; Biomarkers; Biomarkers, Tumor; Biopsy; Bioreactors; Biosensing Techniques; Birth Weight; Blindness; Blood Chemical Analysis; Blood Gas Analysis; Blood Glucose; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Blood-Brain Barrier; Blotting, Western; Body Mass Index; Body Weight; Bone and Bones; Bone Density; Bone Resorption; Borates; Brain; Brain Infarction; Brain Injuries, Traumatic; Brain Neoplasms; Breakfast; Breast Milk Expression; Breast Neoplasms; Bronchi; Bronchoalveolar Lavage Fluid; Buffaloes; Cadherins; Calcification, Physiologic; Calcium Compounds; Calcium, Dietary; Cannula; Caprolactam; Carbon; Carbon Dioxide; Carboplatin; Carcinogenesis; Carcinoma, Ductal; Carcinoma, Ehrlich Tumor; Carcinoma, Hepatocellular; Carcinoma, Non-Small-Cell Lung; Carcinoma, Pancreatic Ductal; Carcinoma, Renal Cell; Cardiovascular Diseases; Carps; Carrageenan; Case-Control Studies; Catalysis; Catalytic Domain; Cattle; CD8-Positive T-Lymphocytes; Cell Adhesion; Cell Cycle Proteins; Cell Death; Cell Differentiation; Cell Line; Cell Line, Tumor; Cell Movement; Cell Nucleus; Cell Phone Use; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Cell Transformation, Viral; Cells, Cultured; Cellulose; Chemical Phenomena; Chemoradiotherapy; Child; Child Development; Child, Preschool; China; Chitosan; Chlorocebus aethiops; Cholecalciferol; Chromatography, Liquid; Circadian Clocks; Circadian Rhythm; Circular Dichroism; Cisplatin; Citric Acid; Clinical Competence; Clinical Laboratory Techniques; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clostridioides difficile; Clostridium Infections; Coculture Techniques; Cohort Studies; Cold Temperature; Colitis; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type XI; Color; Connective Tissue Diseases; Copper; Coronary Angiography; Coronavirus 3C Proteases; Coronavirus Infections; Cost of Illness; Counselors; COVID-19; COVID-19 Testing; Creatine Kinase; Creatinine; Cross-Over Studies; Cross-Sectional Studies; Cryoelectron Microscopy; Cryosurgery; Crystallography, X-Ray; Cues; Cultural Competency; Cultural Diversity; Curriculum; Cyclic AMP Response Element-Binding Protein; Cyclin-Dependent Kinase Inhibitor p21; Cycloparaffins; Cysteine Endopeptidases; Cytokines; Cytoplasm; Cytoprotection; Databases, Factual; Denitrification; Deoxycytidine; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diagnosis, Differential; Diatoms; Diet; Diet, High-Fat; Dietary Exposure; Diffusion Magnetic Resonance Imaging; Diketopiperazines; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Disease Progression; Disease-Free Survival; DNA; DNA Damage; DNA Glycosylases; DNA Repair; DNA-Binding Proteins; DNA, Bacterial; DNA, Viral; Docetaxel; Dose Fractionation, Radiation; Dose-Response Relationship, Drug; Down-Regulation; Doxorubicin; Drosophila; Drosophila melanogaster; Drug Carriers; Drug Delivery Systems; Drug Liberation; Drug Repositioning; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Drug Therapy, Combination; Edema; Edible Grain; Education, Graduate; Education, Medical, Graduate; Education, Pharmacy; Ehlers-Danlos Syndrome; Electron Transport Complex III; Electron Transport Complex IV; Electronic Nicotine Delivery Systems; Emergency Service, Hospital; Empathy; Emulsions; Endothelial Cells; Endurance Training; Energy Intake; Enterovirus A, Human; Environment; Environmental Monitoring; Enzyme Assays; Enzyme Inhibitors; Epithelial Cells; Epithelial-Mesenchymal Transition; Epoxide Hydrolases; Epoxy Compounds; Erythrocyte Count; Erythrocytes; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Esophagectomy; Estrogens; Etanercept; Ethiopia; Ethnicity; Ethylenes; Exanthema; Exercise; Exercise Test; Exercise Tolerance; Extracellular Matrix; Extracorporeal Membrane Oxygenation; Eye Infections, Fungal; False Negative Reactions; Fatty Acids; Fecal Microbiota Transplantation; Feces; Female; Femur Neck; Fermentation; Ferritins; Fetal Development; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fibroblasts; Fibroins; Fish Proteins; Flavanones; Flavonoids; Focus Groups; Follow-Up Studies; Food Handling; Food Supply; Food, Formulated; Forced Expiratory Volume; Forests; Fractures, Bone; Fruit and Vegetable Juices; Fusobacteria; G1 Phase Cell Cycle Checkpoints; G2 Phase Cell Cycle Checkpoints; Gamma Rays; Gastrectomy; Gastrointestinal Microbiome; Gastrointestinal Stromal Tumors; Gefitinib; Gels; Gemcitabine; Gene Amplification; Gene Expression; Gene Expression Regulation; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Neoplastic; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Gene-Environment Interaction; Genotype; Germany; Glioma; Glomerular Filtration Rate; Glucagon; Glucocorticoids; Glycemic Control; Glycerol; Glycogen Synthase Kinase 3 beta; Glycolipids; Glycolysis; Goblet Cells; Gram-Negative Bacterial Infections; Granulocyte Colony-Stimulating Factor; Graphite; Greenhouse Effect; Guanidines; Haemophilus influenzae; HCT116 Cells; Health Knowledge, Attitudes, Practice; Health Personnel; Health Services Accessibility; Health Services Needs and Demand; Health Status Disparities; Healthy Volunteers; Heart Failure; Heart Rate; Heart Transplantation; Heart-Assist Devices; HEK293 Cells; Heme; Heme Oxygenase-1; Hemolysis; Hemorrhage; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Hepatocytes; Hexoses; High-Throughput Nucleotide Sequencing; Hippo Signaling Pathway; Histamine; Histamine Agonists; Histidine; Histone Deacetylase 2; HIV Infections; HIV Reverse Transcriptase; HIV-1; Homebound Persons; Homeodomain Proteins; Homosexuality, Male; Hospice and Palliative Care Nursing; HSP70 Heat-Shock Proteins; Humans; Hyaluronan Receptors; Hydrogen; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hydrolysis; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemia; Hypoglycemic Agents; Hypoxia; Idiopathic Interstitial Pneumonias; Imaging, Three-Dimensional; Imatinib Mesylate; Immunotherapy; Implementation Science; Incidence; INDEL Mutation; Induced Pluripotent Stem Cells; Industrial Waste; Infant; Infant, Newborn; Inflammation; Inflammation Mediators; Infliximab; Infusions, Intravenous; Inhibitory Concentration 50; Injections; Insecticides; Insulin-Like Growth Factor Binding Protein 5; Insulin-Secreting Cells; Interleukin-1; Interleukin-17; Interleukin-8; Internship and Residency; Intestines; Intracellular Signaling Peptides and Proteins; Ion Transport; Iridaceae; Iridoid Glucosides; Islets of Langerhans Transplantation; Isodon; Isoflurane; Isotopes; Italy; Joint Instability; Ketamine; Kidney; Kidney Failure, Chronic; Kidney Function Tests; Kidney Neoplasms; Kinetics; Klebsiella pneumoniae; Knee Joint; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Lactate Dehydrogenase 5; Laparoscopy; Laser Therapy; Lasers, Semiconductor; Lasers, Solid-State; Laurates; Lead; Leukocyte L1 Antigen Complex; Leukocytes, Mononuclear; Light; Lipid Peroxidation; Lipopolysaccharides; Liposomes; Liver; Liver Cirrhosis; Liver Neoplasms; Liver Transplantation; Locomotion; Longitudinal Studies; Lopinavir; Lower Urinary Tract Symptoms; Lubricants; Lung; Lung Diseases, Interstitial; Lung Neoplasms; Lymphocyte Activation; Lymphocytes, Tumor-Infiltrating; Lymphoma, Mantle-Cell; Lysosomes; Macrophages; Male; Manganese Compounds; MAP Kinase Kinase 4; Mass Screening; Maternal Health; Medicine, Chinese Traditional; Melanoma, Experimental; Memantine; Membrane Glycoproteins; Membrane Proteins; Mesenchymal Stem Cell Transplantation; Metal Nanoparticles; Metalloendopeptidases; Metalloporphyrins; Methadone; Methane; Methicillin-Resistant Staphylococcus aureus; Mexico; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Mice, Nude; Mice, SCID; Mice, Transgenic; Microarray Analysis; Microbial Sensitivity Tests; Microbiota; Micronutrients; MicroRNAs; Microscopy, Confocal; Microsomes, Liver; Middle Aged; Milk; Milk, Human; Minority Groups; Mitochondria; Mitochondrial Membranes; Mitochondrial Proteins; Models, Animal; Models, Molecular; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Epidemiology; Molecular Structure; Molecular Weight; Multilocus Sequence Typing; Multimodal Imaging; Muscle Strength; Muscle, Skeletal; Muscular Diseases; Mutation; Mycobacterium tuberculosis; Myocardial Stunning; Myristates; NAD(P)H Dehydrogenase (Quinone); Nanocomposites; Nanogels; Nanoparticles; Nanotechnology; Naphthalenes; Nasal Cavity; National Health Programs; Necrosis; Needs Assessment; Neoadjuvant Therapy; Neonicotinoids; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Recurrence, Local; Neoplasm Staging; Neoplasm Transplantation; Neoplasms; Neoplastic Stem Cells; Netherlands; Neuroblastoma; Neuroprotective Agents; Neutrophils; NF-kappa B; NFATC Transcription Factors; Nicotiana; Nicotine; Nitrates; Nitrification; Nitrites; Nitro Compounds; Nitrogen; Nitrogen Dioxide; North Carolina; Nuclear Magnetic Resonance, Biomolecular; Nuclear Proteins; Nucleic Acid Hybridization; Nucleosomes; Nutrients; Obesity; Obesity, Morbid; Oceans and Seas; Oncogene Protein v-akt; Oncogenes; Oocytes; Open Reading Frames; Osteoclasts; Osteogenesis; Osteoporosis; Osteoporosis, Postmenopausal; Outpatients; Ovarian Neoplasms; Ovariectomy; Overweight; Oxazines; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxides; Oxidoreductases; Oxygen; Oxygen Inhalation Therapy; Oxygenators, Membrane; Ozone; Paclitaxel; Paenibacillus; Pain Measurement; Palliative Care; Pancreatic Neoplasms; Pandemics; Parasympathetic Nervous System; Particulate Matter; Pasteurization; Patient Preference; Patient Satisfaction; Pediatric Obesity; Permeability; Peroxiredoxins; Peroxynitrous Acid; Pharmaceutical Services; Pharmacists; Pharmacy; Phaseolus; Phenotype; Phoeniceae; Phosphates; Phosphatidylinositol 3-Kinases; Phospholipid Transfer Proteins; Phospholipids; Phosphorus; Phosphorylation; Photoperiod; Photosynthesis; Phylogeny; Physical Endurance; Physicians; Pilot Projects; Piperidines; Pituitary Adenylate Cyclase-Activating Polypeptide; Plant Extracts; Plant Leaves; Plant Proteins; Plant Roots; Plaque, Atherosclerotic; Pneumonia; Pneumonia, Viral; Point-of-Care Testing; Polyethylene Glycols; Polymers; Polysorbates; Pore Forming Cytotoxic Proteins; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Postprandial Period; Poverty; Pre-Exposure Prophylaxis; Prediabetic State; Predictive Value of Tests; Pregnancy; Pregnancy Trimester, First; Pregnancy, High-Risk; Prenatal Exposure Delayed Effects; Pressure; Prevalence; Primary Graft Dysfunction; Primary Health Care; Professional Role; Professionalism; Prognosis; Progression-Free Survival; Prolactin; Promoter Regions, Genetic; Proof of Concept Study; Proportional Hazards Models; Propylene Glycol; Prospective Studies; Prostate; Protein Binding; Protein Biosynthesis; Protein Isoforms; Protein Kinase Inhibitors; Protein Phosphatase 2; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Protein Transport; Proteoglycans; Proteome; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Proto-Oncogene Proteins c-ret; Proto-Oncogene Proteins p21(ras); Proton Pumps; Protons; Protoporphyrins; Pseudomonas aeruginosa; Pseudomonas fluorescens; Pulmonary Artery; Pulmonary Disease, Chronic Obstructive; Pulmonary Gas Exchange; Pulmonary Veins; Pyrazoles; Pyridines; Pyrimidines; Qualitative Research; Quinoxalines; Rabbits; Random Allocation; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, Histamine H3; Receptors, Immunologic; Receptors, Transferrin; Recombinant Proteins; Recurrence; Reference Values; Referral and Consultation; Regional Blood Flow; Registries; Regulon; Renal Insufficiency, Chronic; Reperfusion Injury; Repressor Proteins; Reproducibility of Results; Republic of Korea; Research Design; Resistance Training; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency; Resuscitation; Retinal Dehydrogenase; Retreatment; Retrospective Studies; Reverse Transcriptase Inhibitors; Rhinitis, Allergic; Ribosomal Proteins; Ribosomes; Risk Assessment; Risk Factors; Ritonavir; Rivers; RNA Interference; RNA-Seq; RNA, Messenger; RNA, Ribosomal, 16S; RNA, Small Interfering; Rosuvastatin Calcium; Rural Population; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Salivary Ducts; Salivary Gland Neoplasms; San Francisco; SARS-CoV-2; Satiation; Satiety Response; Schools; Schools, Pharmacy; Seasons; Seawater; Selection, Genetic; Sequence Analysis, DNA; Serine-Threonine Kinase 3; Sewage; Sheep; Sheep, Domestic; Shock, Hemorrhagic; Signal Transduction; Silver; Silymarin; Single Photon Emission Computed Tomography Computed Tomography; Sirolimus; Sirtuin 1; Skin; Skin Neoplasms; Skin Physiological Phenomena; Sleep Initiation and Maintenance Disorders; Social Class; Social Participation; Social Support; Soil; Soil Microbiology; Solutions; Somatomedins; Soot; Specimen Handling; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Spinal Fractures; Spirometry; Staphylococcus aureus; STAT1 Transcription Factor; STAT3 Transcription Factor; Streptomyces coelicolor; Stress, Psychological; Stroke; Stroke Volume; Structure-Activity Relationship; Students, Medical; Students, Pharmacy; Substance Abuse Treatment Centers; Sulfur Dioxide; Surface Properties; Surface-Active Agents; Surveys and Questionnaires; Survival Analysis; Survival Rate; Survivin; Sweden; Swine; Swine, Miniature; Sympathetic Nervous System; T-Lymphocytes, Regulatory; Talaromyces; Tandem Mass Spectrometry; tau Proteins; Telemedicine; Telomerase; Telomere; Telomere Homeostasis; Temperature; Terminally Ill; Th1 Cells; Thiamethoxam; Thiazoles; Thiophenes; Thioredoxin Reductase 1; Thrombosis; Thulium; Thyroid Cancer, Papillary; Thyroid Carcinoma, Anaplastic; Thyroid Neoplasms; Time Factors; Titanium; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; TOR Serine-Threonine Kinases; Transcription Factor AP-1; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Transcriptome; Transforming Growth Factor beta1; Transistors, Electronic; Translational Research, Biomedical; Transplantation Tolerance; Transplantation, Homologous; Transportation; Treatment Outcome; Tretinoin; Tuberculosis, Multidrug-Resistant; Tuberculosis, Pulmonary; Tubulin Modulators; Tumor Microenvironment; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha; Twins; Ultrasonic Therapy; Ultrasonography; Ultraviolet Rays; United States; Up-Regulation; Uranium; Urethra; Urinary Bladder; Urodynamics; Uromodulin; Uveitis; Vasoconstrictor Agents; Ventricular Function, Left; Vero Cells; Vesicular Transport Proteins; Viral Nonstructural Proteins; Visual Acuity; Vital Capacity; Vitamin D; Vitamin D Deficiency; Vitamin K 2; Vitamins; Volatilization; Voriconazole; Waiting Lists; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical; Whole Genome Sequencing; Wine; Wnt Signaling Pathway; Wound Healing; Wounds and Injuries; WW Domains; X-linked Nuclear Protein; X-Ray Diffraction; Xanthines; Xenograft Model Antitumor Assays; YAP-Signaling Proteins; Yogurt; Young Adult; Zebrafish; Zebrafish Proteins; Ziziphus

To evaluate the effect of all-trans retinoic acid (ATRA) as treatment for chemotherapy-induced peripheral neuropathy in an experimental animal model and in a randomized, double-blinded, controlled trial in patients with non-small-cell lung cancer (NSCLC).. Forty male Wistar rats were randomized in 5 groups: group A, control; groups B and C, treated with cisplatin; and groups D and E, treated with paclitaxel. ATRA (20 mg/kg PO) was administered for 15 days in groups C and E. We evaluated neuropathy and nerve regeneration-related morphologic changes in sciatic nerve, the concentration of nerve growth factor (NGF), and retinoic acid receptor (RAR)-α and RAR-β expression. In addition, 95 patients with NSCLC under chemotherapy treatment were randomized to either ATRA (20 mg/m(2)/d) or placebo. Serum NGF, neurophysiologic tests, and clinical neurotoxicity were assessed.. The experimental animals developed neuropathy and axonal degeneration, associated with decreased NGF levels in peripheral nerves. Treatment with ATRA reversed sensorial changes and nerve morphology; this was associated with increased NGF levels and RAR-β expression. Patients treated with chemotherapy had clinical neuropathy and axonal loss assessed by neurophysiology, which was related to decreased NGF levels. ATRA reduced axonal degeneration demonstrated by nerve conduction velocity and clinical manifestations of neuropathy grades ≥2.. ATRA reduced chemotherapy-induced experimental neuropathy, increased NGF levels, and induced RAR-β expression in nerve. In patients, reduction of NGF in serum was associated with the severity of neuropathy; ATRA treatment reduced the electrophysiologic alterations.. This study provides Class II evidence that ATRA improves nerve conduction in patients with chemotherapy-induced peripheral neuropathy.

Topics: Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Disease Models, Animal; Double-Blind Method; Female; Humans; Hyperalgesia; Lung Neoplasms; Male; Middle Aged; Polyneuropathies; Rats; Rats, Wistar; Tretinoin

9-cis-Retinoic acid (9-cis-RA) is as active as 13-cis-retinoic acid (13-cis-RA) in inhibiting the proliferation of cultured human sebocytes and in reducing the size of sebaceous glands of hamsters.. Evaluate the anti-acne effect of 9-cis-RA compared to that of 13-cis-RA in a pilot study.. Four young male patients with acne were treated in an open study consecutively with 9-cis-RA and 13-cis-RA given at similar doses.. No beneficial effects were observed with 9-cis-RA in any of the patients whereas all responded favorably to 13-cis-RA.. For the two retinoids tested, the anti-acne effect correlates with the sebosuppressive effect in humans.

Topics: Acne Vulgaris; Administration, Oral; Adolescent; Adult; Alitretinoin; Animals; Cells, Cultured; Cricetinae; Disease Models, Animal; Humans; Isotretinoin; Keratolytic Agents; Male; Pilot Projects; Retinoids; Sebaceous Glands; Sebum; Treatment Outcome; Tretinoin

Liver fibrosis is one of the most common liver diseases with substantial morbidity and mortality. However, effective therapy for liver fibrosis is still lacking. Considering the key fibrogenic role of activated hepatic stellate cells (aHSCs), here we reported a strategy to deplete aHSCs by inducing apoptosis as well as quiescence. Therefore, we engineered biomimetic all-trans retinoic acid (ATRA) loaded PLGA nanoparticles (NPs). HSC (LX2 cells) membranes, presenting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were coated on the surface of the nanoparticles, while the clinically approved agent ATRA with anti-fibrosis ability was encapsulated in the inner core. The biomimetic coating of TRAIL-expressing HSC membranes does not only provide homologous targeting to HSCs, but also effectively triggers apoptosis of aHSCs. ATRA could induce quiescence of activated fibroblasts. While TM-NPs (i.e. membrane coated NPs without ATRA) and ATRA/NPs (i.e. non-coated NPs loaded with ATRA) only showed the ability to induce apoptosis and decrease the α-SMA expression in aHSCs, respectively, TM-ATRA/NPs induced both apoptosis and quiescence in aHSCs, ultimately leading to improved fibrosis amelioration in both carbon tetrachloride-induced and methionine and choline deficient L-amino acid diet induced liver fibrosis mouse models. We conclude that biomimetic TM-ATRA/NPs may provide a novel strategy for effective antifibrosis therapy.

Topics: Animals; Apoptosis; Biomimetics; Disease Models, Animal; Hepatic Stellate Cells; Liver; Liver Cirrhosis; Mice; Nanoparticles; Tretinoin

CD8

Topics: Animals; CD8-Positive T-Lymphocytes; Cytokines; Disease Models, Animal; Forkhead Transcription Factors; Graft vs Host Disease; Humans; Mammals; Mice; Sirolimus; T-Lymphocytes, Regulatory; Tretinoin

In addition to their core symptoms, most individuals with autism spectrum disorder (ASD) also experience motor impairments. These impairments are often linked to the cerebellum, which is the focus of the current study. Herein, we utilized a prenatal valproic acid (VPA)-induced rat model of autism and performed RNA sequencing in the cerebellum. Relative to control animals, the VPA-treated offspring demonstrated both abnormal motor coordination and impaired dendritic arborization of Purkinje cells (PCs). Concurrently, we observed a decrease in the cerebellar expression of retinoic acid (RA) synthesis enzymes (RDH10, ALDH1A1), metabolic enzyme (CYP26A2), and lower levels of RA, retinoic acid receptor α (RARα), and Cerebellin2 (CBLN2) in the VPA-treated offspring. However, RA supplementation ameliorated these deficits, restoring motor coordination, normalizing PCs dendritic arborization, and increasing the expression of RA, RARα, and CBLN2. Further, ChIP assays confirmed that RA supplementation enhanced RARα's binding capacity to CBLN2 promoters. Collectively, these findings highlight the therapeutic potential of RA for treating motor incoordination in VPA-induced autism, acting through the RARα-CBLN2 pathway.

Topics: Animals; Ataxia; Autism Spectrum Disorder; Autistic Disorder; Cerebellum; Dietary Supplements; Disease Models, Animal; Female; Humans; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Tretinoin; Valproic Acid

Systemic sclerosis (SSc) is an autoimmune connective tissue disease that leads to irreversible fibrosis of the skin and the internal organs. The etiology of SSc is complex, its pathophysiology is poorly understood, and clinical therapeutic options are restricted. Thus, research into medications and targets for treating fibrosis is essential and urgent. Fos-related antigen 2 (Fra2) is a transcription factor that is a member of the activator protein-1 family. Fra2 transgenic mice were shown to have spontaneous fibrosis. All-trans retinoic acid (ATRA) is a vitamin A intermediate metabolite and ligand for the retinoic acid receptor (RAR), which possesses anti-inflammatory and anti-proliferative properties. Recent research has demonstrated that ATRA also has an anti-fibrotic effect. However, the exact mechanism is not fully understood. Interestingly, we identified potential binding sites for the transcription factor RARα to the promoter region of the FRA2 gene through JASPAR and PROMO databases. In this study, the pro-fibrotic effect of Fra2 in SSc is confirmed. SSc dermal fibroblasts and bleomycin-induced fibrotic tissues of SSc animals exhibit increased levels of Fra2. Inhibition of Fra2 expression in SSc dermal fibroblasts with Fra2 siRNA markedly decreased collagen I expression. ATRA reduced the expressions of Fra2, collagen I, and α-smooth muscle actin(α-SMA) in SSc dermal fibroblasts and bleomycin-induced fibrotic tissues of SSc mice. In addition, chromatin immunoprecipitation and dual-luciferase assays demonstrated that retinoic acid receptor RARα binds to the FRA2 promoter and modulates its transcriptional activity. ATRA decreases collagen I expression both in vivo and in vitro via the reduction of Fra2 expression. This work establishes the rationale for expanding the use of ATRA in the treatment of SSc and indicates that Fra2 can be used as an anti-fibrotic target.

Topics: Animals; Bleomycin; Collagen Type I; Disease Models, Animal; Fibroblasts; Fibrosis; Mice; Mice, Transgenic; Receptors, Retinoic Acid; Scleroderma, Systemic; Skin; Transcription Factor AP-1; Tretinoin

Acute myeloid leukemia (AML) patients bearing the ITD mutation in the tyrosine kinase receptor FLT3 (FLT3-ITD) present a poor prognosis and a high risk of relapse. FLT3-ITD is retained in the endoplasmic reticulum (ER) and generates intrinsic proteotoxic stress. We devised a strategy based on proteotoxic stress, generated by the combination of low doses of the differentiating agent retinoic acid (R), the proteasome inhibitor bortezomib (B), and the oxidative stress inducer arsenic trioxide (A).. We treated FLT3-ITD. The combination RBA exerts strong cytotoxic activity on FLT3-ITD. Our findings strengthen our previous work indicating induction of proteotoxic stress as a possible strategy in FLT3-ITD

Topics: Animals; Ascorbic Acid; Cell Death; Cytoprotection; Disease Models, Animal; Humans; Mechanotransduction, Cellular; Mice; Proteotoxic Stress; Tretinoin

Optimal tissue recovery and organismal survival are achieved by spatiotemporal tuning of tissue inflammation, contraction and scar formation

Topics: Animals; Cell Differentiation; Cell Hypoxia; Cell Lineage; Disease Models, Animal; Endothelial Protein C Receptor; Fascia; Fibroblasts; Gene Expression Profiling; Inflammation; Mice; Myofibroblasts; Signal Transduction; Single-Cell Gene Expression Analysis; Skin; Tretinoin; Wound Healing

Rod and cone photoreceptors degenerate in retinitis pigmentosa (RP). While downstream neurons survive, they undergo physiological changes, including accelerated spontaneous firing in retinal ganglion cells (RGCs). Retinoic acid (RA) is the molecular trigger of RGC hyperactivity, but whether this interferes with visual perception is unknown. Here, we show that inhibiting RA synthesis with disulfiram, a deterrent of human alcohol abuse, improves behavioral image detection in vision-impaired mice. In vivo Ca

Topics: Animals; Disease Models, Animal; Mice; Retinal Degeneration; Retinal Ganglion Cells; Retinitis Pigmentosa; Tretinoin

Retinitis Pigmentosa (RP) is a progressive, debilitating visual disorder caused by mutations in a diverse set of genes. In both humans with RP and mouse models of RP, rod photoreceptor dysfunction leads to loss of night vision, and is followed by secondary cone photoreceptor dysfunction and degeneration, leading to loss of daylight color vision. A strategy to prevent secondary cone death could provide a general RP therapy to preserve daylight color vision regardless of the underlying mutation. In mouse models of RP, cones in the peripheral retina survive long-term, despite complete rod loss. The mechanism for such peripheral cone survival had not been explored. Here, we found that active retinoic acid (RA) signaling in peripheral Muller glia is necessary for the abnormally long survival of these peripheral cones. RA depletion by conditional knockout of RA synthesis enzymes, or overexpression of an RA degradation enzyme, abrogated the extended survival of peripheral cones. Conversely, constitutive activation of RA signaling in the central retina promoted long-term cone survival. These results indicate that RA signaling mediates the prolonged peripheral cone survival in the rd1 mouse model of retinal degeneration, and provide a basis for a generic strategy for cone survival in the many diseases that lead to loss of cone-mediated vision.

Topics: Animals; Color Vision; Disease Models, Animal; Mice; Retina; Retinal Cone Photoreceptor Cells; Retinal Degeneration; Retinitis Pigmentosa; Tretinoin

Dendritic spines are the central postsynaptic machinery that determines synaptic function. The F-actin within dendritic spines regulates their dynamic formation and elimination. Rai14 is an F-actin-regulating protein with a membrane-shaping function. Here, we identified the roles of Rai14 for the regulation of dendritic spine dynamics associated with stress-induced depressive-like behaviors. Rai14-deficient neurons exhibit reduced dendritic spine density in the

Topics: Actin Cytoskeleton; Actins; Animals; Dendritic Spines; Disease Models, Animal; Mice; Neurons; Tretinoin

Obesity and malnutrition both cause dysbiosis and dampen retinoic acid (RA) signaling pathways, which play pivotal roles in biological processes. The current study evaluates a hypothesis that colitis-associated dysbiosis also has systemic negative impacts on RA signaling. Thus, we studied the effects of inflammation, under a vitamin A-sufficient condition, on RA signaling using mouse colitis models induced by dextran sulfate sodium. That data showed that intestinal inflammation resulted in reduced RA signaling in the liver, brain, gut, and adipose tissues measured by analyzing the expression of genes encoding for the synthesis, oxidation, transport, and receptor of RA. The expression of RA-regulated gut homing molecules including α4β7 integrin, and CCR9, along with MADCAM1 were all reduced in colitis mice revealing compromised immunity due to reduced RA signaling. The data also showed that the development of colitis was accompanied by dysbiosis featured with reduced Lactobacillaceae and Verrucomicrobiaceae but an expansion of Erysipelotrichaceae and others. Colitis resulted in reduced butyrate-producing bacteria and increased methane-generating bacteria. Additionally, dysbiosis was associated with induced Il-1β, Ifn-γ, and Tnf-α mRNA but reduced Il-22, Il-17f, and Rorγt transcripts in the colon. Together, intestinal inflammation inhibits RA signaling in multiple organs. RA is essential in regulating various biological processes, it is critical to detect RA signaling reduction in tissues even when vitamin A deficiency is absent. Moreover, probiotics can potentially prevent dysbiosis and reverse compromised RA signaling, having systemic health benefits.

Topics: Animals; Colitis; Colon; Dextran Sulfate; Disease Models, Animal; Dysbiosis; Gastrointestinal Microbiome; Inflammation; Mice; Mice, Inbred C57BL; Tretinoin

Whey acidic protein four-disulfide core domain protein 12 (WFDC12) has been implicated in the pathogenesis of psoriasis but the specific molecular mechanism is not clearly defined. In this study, we found the expression of WFDC12 protein closely correlated with psoriasis. WFDC12 in keratinocyte might increase infiltration of Langerhans cells (LCs) and monocyte-derived dendritic cells (moDDCs), up-regulating the co-stimulation molecular CD40/CD86. Th1 cells in lymph nodes were higher in K14-WFDC12 transgenic psoiasis-like mice. Meanwhile, the mRNA of IL-12 and IFN-γ in the lesion skin was significantly increased in transgenic mice. Moreover, we found that the expression of the proteins that participated in the retinoic acid-related pathway and immune signaling pathway was more changed in the lesion skin of K14-WFDC12 transgenic psoriasis-like mice. Collectively, the results implied that WFDC12 might affect the activation of the retinoic acid signaling pathway and regulate the infiltration of DC cells in the skin lesions and lymph nodes, thereby inducing Th1 cells differentiation and increasing the secretion of IFN-γ to exacerbate psoriasis in mice.

Topics: Animals; Disease Models, Animal; Interleukin-12; Mice; Mice, Transgenic; Milk Proteins; Psoriasis; RNA, Messenger; Tretinoin

Hyperexcitability of brain circuits is a common feature of autism spectrum disorders (ASDs). Genetic deletion of a chromatin-binding protein,

Topics: Animals; Chromatin; Disease Models, Animal; Hippocampus; Mice; Phenotype; Seizures; Smith-Magenis Syndrome; Trans-Activators; Tretinoin

The incidence of inflammatory bowel disease (IBD) is increasing; hence, effective treatments are warranted. The therapeutic effect of human carbonic anhydrase I (hCA I) in IBD remains unknown. Therefore, we investigated whether oral tolerization to hCA I would induce antigen-specific protection from intestinal inflammation in vivo. Severe combined immunodeficient mice received hCA I, keyhole limpet hemocyanin (KLH), or phosphate-buffered saline (PBS) orally for 7 days. Colons and mesenteric lymph nodes (MLNs) were collected 4 weeks after cell transfer. Additionally, the mechanisms underlying the therapeutic effects were investigated. The comparison between the effects of well-established drugs and hCA I oral administration was investigated. Oral administration of hCA I ameliorated colitis remarkably. hCA I reached the cecum and ameliorated colitis more effectively than mesalazine and similarly to prednisolone. Compared with PBS treatment, hCA I treatment reduced interleukin (IL)-17a, IL-6, and retinoic acid-related orphan receptor gamma t (RORγt) expression in the colon or MLNs; moreover, hCA I markedly reduced IL-6, IL-17, and interferon-gamma (IFN-γ) levels in the MLN. Oral administration of hCA I induced immune tolerance and suppressed colitis in vivo. Thus, hCA I administration could be proposed as a new treatment option for IBD.

Topics: Administration, Oral; Animals; Carbonic Anhydrase I; Colitis; Disease Models, Animal; Humans; Inflammatory Bowel Diseases; Interferon-gamma; Interleukin-17; Interleukin-6; Mesalamine; Mice; Mice, SCID; Nuclear Receptor Subfamily 1, Group F, Member 3; Phosphates; Prednisolone; Tretinoin

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Breast Neoplasms; Cell Line, Tumor; Chitosan; Disease Models, Animal; Doxorubicin; Drug Liberation; Drug Synergism; Female; Folic Acid; Gene Knockdown Techniques; Humans; Mice; Micelles; Nanoparticle Drug Delivery System; Neoplastic Stem Cells; NIMA-Interacting Peptidylprolyl Isomerase; Tissue Distribution; Tretinoin

Gut-microbiota dysbiosis links to allergic diseases. The mechanism of the exacerbation of food allergy caused by gut-microbiota dysbiosis remains unknown. Regulation of retinoic acid receptor alpha (RARα) signaling is critical for gut immune homeostasis. Here we clarified that RARα in dendritic cells (DCs) promotes Th2 cell differentiation. Antibiotics treatment stimulates retinoic acid signaling in mucosal DCs. We found microbiota metabolites short-chain fatty acids (SCFAs) maintain IGF-1 levels in serum and mesenteric lymph nodes. The IGF-1/Akt pathway is essential for regulating the transcription of genes targeted by RARα. And RARα in DCs affects type I interferon (IFN-I) responses through regulating transcription of IFN-α. Our study identifies SCFAs crosstalk with RARα in dendritic cells as a critical modulator that plays a core role in promoting Th2 cells differentiation at a state of modified/disturbed microbiome.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Cells, Cultured; Dendritic Cells; Disease Models, Animal; Dysbiosis; Fatty Acids, Volatile; Food Hypersensitivity; Gastrointestinal Microbiome; Insulin-Like Growth Factor I; Interferon Type I; Mice, Inbred C57BL; Mice, Knockout; Proto-Oncogene Proteins c-akt; Retinoic Acid Receptor alpha; Signal Transduction; Th2 Cells; Tretinoin

Radiotherapy (RT) is an important anti-cancer treatment modality that activates innate and adaptive immune responses. When all-trans retinoic acid (RA) was administered with radiation, we observed superior antitumor responses compared to ionizing radiation (IR) alone or RA alone. The superior antitumor effects of combination treatment were accompanied by a dramatic increase of TNF-α- and inducible nitric oxide synthase (iNOS)-producing inflammatory macrophages in local and distal non-irradiated (distal) tumors. Inflammatory macrophages are essential for the therapeutic efficacy of combination treatment by inducing effector T cell infiltration and enhancing the effector T cell to regulatory T cell ratio in local and distal tumors. T cells and T cell-derived IFN-γ are crucial for increasing inflammatory macrophage levels in IR and RA treated tumors. Notably, whereas CD8

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Chemoradiotherapy; Disease Models, Animal; Humans; Interferon-gamma; Macrophages; Mice; Mice, Knockout; Neoplasms; Radiation Tolerance; Receptors, CCR2; Tretinoin; Tumor Microenvironment

Myeloid-derived suppressor cells (MDSC) are known to inhibit functions of T and NK cells. MDSC have been shown to be generated and to accumulate under chronic inflammatory conditions that are typical for cancer. Therefore, it would be highly beneficial to find ways to diminish the number and immunosuppressive functions of these cells in tumor-bearing hosts. Here we describe current protocols to deplete MDSC or induce their maturation in preclinical tumor models that could lead to the attenuation of their immunosuppressive functions.

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Cell Differentiation; Disease Models, Animal; Mice, Inbred C57BL; Mice, Transgenic; Myeloid-Derived Suppressor Cells; Neoplasms; Paclitaxel; Tretinoin

Thrombosis is a leading cause of morbidity and mortality. Fibrinogen, the soluble substrate for fibrin-based clotting, has a central role in haemostasis and thrombosis and its plasma concentration correlates with cardiovascular disease event risk and a prothrombotic state in experimental models. We aimed to identify chemical entities capable of changing fibrinogen production and test their impact on experimental thrombosis. A total of 1,280 bioactive compounds were screened for their ability to alter fibrinogen production by hepatocyte-derived cancer cells and a selected panel was tested in zebrafish larvae. Anthralin and all-

Topics: Animals; Animals, Genetically Modified; Anthralin; Blood Coagulation; Disease Models, Animal; Fibrinogen; Fibrinolytic Agents; Hep G2 Cells; Hepatocytes; Humans; Integrin alpha2; Morpholinos; Mutation; Oligonucleotides, Antisense; Proteomics; Small Molecule Libraries; Tretinoin; Venous Thrombosis; Zebrafish; Zebrafish Proteins

To investigate the effect of short-wavelength light (SL) on guinea pigs with lens-induced myopia (LIM) and the possible retinoic acid (RA)-related mechanisms.. Two-week-old guinea pigs (n = 60) with monocular -5D lenses were reared under white light (WL, 580 lux) or SL (440 nm, 500 lux). The left eyes were uncovered as control. Refractive error (RE) and axial length (AL) were measured at baseline, one week, two weeks, and four weeks after intervention. Retinal RA was measured from four guinea pigs after two and four weeks of treatment with HPLC. Two-week-old guinea pigs (n = 52) with monocular -5D lens were fed with either RA or its synthesis inhibitor citral every third day in the morning, and half from each group were reared under WL or SL conditions. RE and AL were recorded at baseline and two and four weeks after intervention. Retinal RA was measured after four weeks of intervention.. At the end of treatment, guinea pigs exposed to SL were less myopic than to WL (2.06 ± 1.69D vs. -1.00 ± 1.88D), accompanied with shorter AL (P = 0.01) and less retinal RA (P = 0.02). SL reduced retinal RA even after exogenous RA supplementation (P = 0.02) and decelerated LIM compared to WL (1.66 ± 1.03D vs. -3.53 ± 0.90D). Citral slowed ocular growth, leading to similar RE in W+CI and S+CI groups (3.39 ± 1.65D vs. 5.25 ± 0.80D).. Overall, SL reduced LIM in guinea pigs, even in those supplemented with oral RA, accompanied by reduced retinal RA levels. Oral RA accelerated eye elongation, but citral equally decelerated eye elongation under SL and WL with no significant retinal RA reduction.

Topics: Animals; Axial Length, Eye; Biometry; Chromatography, High Pressure Liquid; Contact Lenses; Disease Models, Animal; Guinea Pigs; Light; Myopia; Refraction, Ocular; Retina; Retinoscopy; Tretinoin

Idiopathic pulmonary fibrosis (IPF) primarily affects the aged population and is characterised by failure of alveolar regeneration, leading to loss of alveolar type 1 (AT1) cells. Aged mouse models of lung repair have demonstrated that regeneration fails with increased age. Mouse and rat lung repair models have shown retinoic acid (RA) treatment can restore alveolar regeneration. Herein, we seek to determine the signalling mechanisms that become activated on RA treatment prior to injury, which support alveolar differentiation.. Partial pneumonectomy lung injury model and next-generation sequencing of sorted cell populations were used to uncover molecular targets regulating alveolar repair. In vitro organoids generated from epithelial cells of mouse or patient with IPF co-cultured with young, aged or RA-pretreated murine fibroblasts were used to test potential targets.. Known alveolar epithelial cell differentiation markers, including HOPX and AGER for AT1 cells, were used to assess outcome of treatments.. Gene expression analysis of sorted fibroblasts and epithelial cells isolated from lungs of young, aged and RA-pretreated aged mice predicted increased platelet-derived growth factor subunit A (PDGFA) signalling that coincided with regeneration and alveolar epithelial differentiation. Addition of PDGFA induced AT1 and AT2 differentiation in both mouse and human IPF lung organoids generated with aged fibroblasts, and PDGFA monoclonal antibody blocked AT1 cell differentiation in organoids generated with young murine fibroblasts.. Our data support the concept that RA indirectly induces reciprocal PDGFA signalling, which activates regenerative fibroblasts that support alveolar epithelial cell differentiation and repair, providing a potential therapeutic strategy to influence the pathogenesis of IPF.

Topics: Age Factors; Alveolar Epithelial Cells; Animals; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Idiopathic Pulmonary Fibrosis; Mice; Platelet-Derived Growth Factor; Signal Transduction; Tretinoin; Up-Regulation

All-trans retinoic acid (ATRA) is one of essentially active metabolite of vitamin A, and plays an important role in diverse physiological processes, such as cellular growth and function. Renal interstitial fibrosis (RIF) is a common pathological characteristic of chronic renal disease causing end-stage renal disease currently lacking effective treatment. Low level of Angiopoietins-1 (Angpt-1) is associated with extracellular matrix accumulation and fibrosis diseases. This study was performed to assess the association of ATRA with Angpt-1 in RIF disease. Rats were divided into three groups: group of sham (SHO group), group of unilateral ureteral obstruction group (UUO group), UUO mice administrated daily at the dose of ATRA (ATRA group). Masson-staining was used to detect the histologic lesion. Immunohistochemistry and Western-blot were applied to determine the targeted proteins. RIF score was significantly increased in UUO rats when compared with that of SHO group, and the fibrosis score was notably reduced in ATRA group. Transforming growth factor-β1 (TGF-β1), collagen IV (Col-IV) and fibronectin (FN) expressions in UUO group were significantly up-regulated, whereas Angpt-1 expression was significantly down-regulated compared with the SHO group. ATRA treatment reduced TGF-β1, Col-IV and FN expressions and improved Angpt-1 expression compared with the UUO group. The protein expression of Angpt-1 in kidney tissue of UUO group was negatively correlated with RIF index and protein expressions of Col-IV, FN and TGF-β1. In conclusion, low expression of Angpt-1 was associated with the RIF disease and ATRA treatment can increase the Angpt-1 and alleviate the RIF lesion in UUO rats.

Topics: Angiopoietin-1; Animals; Collagen Type IV; Disease Models, Animal; Disease Progression; Down-Regulation; Extracellular Matrix; Fibronectins; Fibrosis; Male; Nephritis, Interstitial; Rats; Transforming Growth Factor beta1; Tretinoin

Cerebral ischemia is a neurological disorder that leads to cognitive decline and high mortality. Retinoic acid is a metabolite of vitamin A that has anti-inflammatory and anti-apoptotic effects. This study investigated whether retinoic acid prevents neuronal cell damage on focal cerebral ischemia through modulating apoptosis signaling pathway. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia in adult male rats. Retinoic acid (5 mg/kg) or vehicle was injected intraperitoneally for 4 days prior to MCAO. Neurological behavior deficit tests were performed 24 h after MCAO. Brain edema and infarct volume were measured, and TUNEL histochemistry was carried out. We also investigated the changes in apoptosis-related proteins including bcl-2 family proteins and caspases. MCAO injury induced severe neurological behavior deficits and brain edema. It also increased infarct volume, histopathological damages, and the number of TUNEL-positive cells in cerebral cortex. However, retinoic acid pretreatment attenuated MCAO-induced neurological behavior deficits, brain edema, and infarction. It also alleviated histopathological lesion and decreased the number of TUNEL-positive cells. Bcl-2 and bax proteins are representative bcl-2 family proteins. MCAO injury induced a decrease in bcl-2 expression and an increase in bax expression, and retinoic acid pretreatment alleviated these changes. MCAO injury caused a decrease in bcl-2/bax expression ratio in cerebral cortex, while retinoic acid restored this decrease by MCAO. Moreover, our result showed increases in caspase-9, caspase-3, PARP protein levels in MCAO-operated animals. Retinoic acid pretreatment prevented these increases. We identified the changes in cleaved forms of these proteins, similar to the changes in full-length protein. Activation of caspases and PARP proteins are considered to be representative apoptosis indicators. This study showed that retinoic acid regulates bcl-2 family proteins and caspase proteins in focal cerebral ischemia. Thus, our findings demonstrate that retinoic acid exhibits a neuroprotective effect against ischemic damage by modulating apoptosis signaling pathway.

Topics: Animals; Apoptosis; Caspase 3; Disease Models, Animal; Humans; Infarction, Middle Cerebral Artery; Male; Neurons; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Tretinoin

Disorders of the transparent cornea affect millions of people worldwide. However, how to maintain and/or regenerate this organ remains unclear. Here, we show that

Topics: Age Factors; Aldehyde Dehydrogenase 1 Family; Animals; Burns, Chemical; Cell Differentiation; Cell Proliferation; Cells, Cultured; Cellular Senescence; Corneal Neovascularization; Corneal Stroma; Disease Models, Animal; Epithelium, Corneal; Eye Burns; Mice, Knockout; Regeneration; Retinal Dehydrogenase; Signal Transduction; Stem Cells; Transcription Factor RelA; Tretinoin

Neural tube defects are a common congenital anomaly involving incomplete closure of the spinal cord. Myelomeningocele (MMC) is a severe form in which there is complete exposure of neural tissue with a lack of skin, soft tissue, or bony covering to protect the spinal cord. The all-trans retinoic acid (ATRA) induced rat model of (MMC) is a reproducible, cost-effective means of studying this disease; however, there are limited modalities to objectively quantify disease severity, or potential benefits from experimental therapies. We sought to determine the feasibility of detecting differences between MMC and wild type (WT) rat fetuses using diffusion magnetic resonance imaging techniques (MRI). Rat dams were gavage-fed ATRA to produce MMC defects in fetuses, which were surgically delivered prior to term. Average diffusion coefficient (ADC) and fractional anisotropy (FA) maps were obtained for each fetus. Brain volumes and two anatomically defined brain length measurements (D1 and D2) were significantly decreased in MMC compared to WT. Mean ADC signal was significantly increased in MMC compared to WT, but no difference was found for FA signal. In summary, ADC and brain measurements were significantly different between WT and MMC rat fetuses. ADC could be a useful complementary imaging biomarker to current histopathologic analysis of MMC models, and potentially expedite therapeutic research for this disease.

Topics: Animals; Brain; Diffusion Magnetic Resonance Imaging; Disease Models, Animal; Feasibility Studies; Female; Fetus; Humans; Meningomyelocele; Pregnancy; Rats; Spinal Cord; Tretinoin

Intercellular communications are important for maintaining normal physiological processes. An important intercellular communication is mediated by the exchange of membrane-enclosed extracellular vesicles. Among various vesicles, exosomes can be detected in a wide variety of biological systems, but the regulation and biological implication of exosome secretion/uptake remains largely unclear.. Cellular retinoic acid (RA) binding protein 1 (Crabp1) knockout (CKO) mice were used for in vivo studies. Extracellular exosomes were monitored in CKO mice and relevant cell cultures including embryonic stem cell (CJ7), macrophage (Raw 264.7) and hippocampal cell (HT22) using Western blot and flow cytometry. Receptor Interacting Protein 140 (RIP140) was depleted by Crispr/Cas9-mediated gene editing. Anti-inflammatory maker was analyzed using qRT-PCR. Clinical relevance was accessed by mining multiple clinical datasets.. This study uncovers Crabp1 as a negative regulator of exosome secretion from neurons. Specifically, RIP140, a pro-inflammatory regulator, can be transferred from neurons, via Crabp1-regulated exosome secretion, into macrophages to promote their inflammatory polarization. Consistently, CKO mice, defected in the negative control of exosome secretion, have significantly elevated RIP140-containing exosomes in their blood and cerebrospinal fluid, and exhibit an increased vulnerability to systemic inflammation. Clinical relevance of this pathway is supported by patients' data of multiple inflammatory diseases. Further, the action of Crabp1 in regulating exosome secretion involves its ligand and is mediated by its downstream target, the MAPK signaling pathway.. This study presents the first evidence for the regulation of exosome secretion, which mediates intercellular communication, by RA-Crabp1 signaling. This novel mechanism can contribute to the control of systemic inflammation by transferring an inflammatory regulator, RIP140, between cells. This represents a new mechanism of vitamin A action that can modulate the homeostasis of system-wide innate immunity without involving gene regulation. Video Abstract.

Topics: Animals; Cell Communication; CRISPR-Cas Systems; Disease Models, Animal; Exosomes; Extracellular Vesicles; Homeostasis; Humans; Inflammation; Mice; Mice, Knockout; Neurons; Nuclear Receptor Interacting Protein 1; RAW 264.7 Cells; Receptors, Retinoic Acid; Signal Transduction; Tretinoin

Coronary artery (CA) stenosis is a detrimental and often life-threatening sequela in Kawasaki disease (KD) patients with coronary artery aneurysm (CAA). Therapeutic strategies for these patients have not yet been established. All-trans-retinoic acid (atRA) is a modulator of smooth muscle cell functions. The purpose of this study was to investigate the effect of atRA on CA stenosis in a mouse model of KD. Lactobacillus casei cell wall extract (LCWE) was intraperitoneally injected into 5-week-old male C57BL/6 J mice to induce CA stenosis. Two weeks later, the mice were orally administered atRA (30 mg/kg) 5 days per week for 14 weeks (LCWE + atRA group, n = 7). Mice in the untreated group (LCWE group, n = 6) received corn oil alone. Control mice were injected with phosphate-buffered saline (PBS, n = 5). Treatment with atRA significantly suppressed CA inflammation (19.3 ± 2.8 vs 4.4 ± 2.8, p < 0.0001) and reduced the incidence of CA stenosis (100% vs 18.5%, p < 0.05). In addition, atRA suppressed the migration of human coronary artery smooth muscle cells (HCASMCs) induced by platelet-derived growth factor subunit B homodimer (PDGF-BB). In conclusion, atRA dramatically alleviated CA stenosis by suppressing SMC migration. Therefore, it is expected to have clinical applications preventing CA stenosis in KD patients with CAA.

Topics: Aneurysm; Animals; Cell Movement; Cell Wall; Coronary Stenosis; Coronary Vessels; Disease Models, Animal; Humans; Lacticaseibacillus casei; Lipopolysaccharides; Mice; Mucocutaneous Lymph Node Syndrome; Myocytes, Smooth Muscle; Tretinoin

Translational models of myelomeningocele (MMC) are needed to test novel. Time-mated Dunkin Hartley guinea pig dams were dosed with 60 mg/kg of RA between gestation age (GA) 12 and 15 days in the development of an RA model. Fetuses were grossly evaluated for MMC lesions at Cesarean section after GA 31 days. Evaluation of the ability of pregnant guinea pig dams to tolerate uterine surgical intervention was performed by hysterotomy of a separated group of time-mated guinea pigs at GA 45, 50, and 55.. Forty-two pregnant guinea pigs were dosed with RA, with a total of 189 fetuses. The fetal demise rate was 38% (. RA dosed at 60 mg/kg in guinea pigs between GA 12 and 15 did not result in MMC. Dunkin Hartley guinea pigs did not tolerate a hysterotomy near term in our surgical model. Further work is needed to determine if MMC can be induced in guinea pigs with alternate RA dosing.

Topics: Animals; Cesarean Section; Disease Models, Animal; Female; Fetal Diseases; Gestational Age; Guinea Pigs; Humans; Hysterotomy; Meningomyelocele; Pregnancy; Tretinoin

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

The aim of the present study is to explore the effect of retinoic acid (RA) on cardiac injury induced by gestational diabetes mellitus (GDM). GDM mice were given 3 mg/kg RA once daily until the 19th day of pregnancy or the 7th day of post-partum. Compared to normal control and normal pregnant control mice, GDM mice before and after delivery showed significantly cardiac injury. RA treatment attenuated cardiac injury as evidenced by decreased heart mass and left ventricular mass, mRNA expressions of ANP and BNP, and cardiac fibrosis compared with that in GDM mice. The protective effect of RA on GDM cardiomyopathy was related to the decreased MDA content and ROS generation, the increased GSH-Px and SOD content as well as the reduced TNF-α and IL-1β content and inhibition of NF-κB signaling. In addition, RA treatment delayed the continuous rise of blood glucose before delivery and decreased the higher level of glucose after delivery. In conclusion, RA treatment could increase the activity of the antioxidant enzyme and suppress the oxidative stress, inflammation response, and activation of NF-κB signaling, thereby improving blood glucose level and cardiac injury of GDM mice before and after delivery.

Topics: Animals; Antioxidants; Diabetes, Gestational; Disease Models, Animal; Female; Heart Injuries; Heart Ventricles; Hyperglycemia; Inflammation; Interleukin-1beta; Male; Mice; NF-kappa B; Oxidative Stress; Pregnancy; Reactive Oxygen Species; Signal Transduction; Tretinoin; Tumor Necrosis Factor-alpha

Intestinal epithelial apical membrane Cl-/HCO3- exchanger DRA (downregulated in adenoma, SLC26A3) has emerged as an important therapeutic target for diarrhea, emphasizing the potential therapeutic role of agents that upregulate DRA. All-trans retinoic acid (ATRA), a key vitamin A metabolite, was earlier shown by us to stimulate DRA expression in intestinal epithelial cells. However, its role in modulating DRA in gut inflammation has not been investigated.. Our aim was to analyze the efficacy of ATRA in counteracting inflammation-induced decrease in DRA in vitro and in vivo.. Interferon-γ (IFN-γ)-treated Caco-2 cells and dextran sulfate sodium (DSS)-treated C57BL/6J mice served as in vitro and in vivo models of gut inflammation, respectively. The effect of ATRA on IFN-γ-mediated inhibition of DRA function, expression, and promoter activity were elucidated. In the DSS colitis model, diarrheal phenotype, cytokine response, in vivo imaging, myeloperoxidase activity, and DRA expression were measured in the distal colon.. All-trans retinoic acid (10 μM, 24 h) abrogated IFN-γ (30 ng/mL, 24 h)-induced decrease in DRA function, expression, and promoter activity in Caco-2 cells. All-trans retinoic acid altered IFN-γ signaling via blocking IFN-γ-induced tyrosine phosphorylation of STAT-1. All-trans retinoic acid cotreatment (1 mg/kg BW, i.p. daily) of DSS-treated mice (3% in drinking water for 7 days) alleviated colitis-associated weight loss, diarrheal phenotype, and induction of IL-1β and CXCL1 and a decrease in DRA mRNA and protein levels in the colon.. Our data showing upregulation of DRA under normal and inflammatory conditions by ATRA demonstrate a novel role of this micronutrient in alleviating IBD-associated diarrhea.

Topics: Animals; Antiporters; Caco-2 Cells; Chloride-Bicarbonate Antiporters; Colitis; Colon; Dextran Sulfate; Diarrhea; Disease Models, Animal; Epithelial Cells; Humans; Inflammation; Interferon-gamma; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; RNA, Messenger; Sulfate Transporters; Tretinoin; Up-Regulation; Weight Loss

The molecular mechanisms of abnormal palatogenesis were investigated in this study. A key regulator, miR-106a-5p, and its target pathway were analyzed.. This research is trying to clarify the underlying mechanism of the modulation of miRNA transcription during the formation of cleft palate by 7T and 9.4T NMR metabolomic platforms.. Differentially expressed miRNAs and mRNAs were analyzed by microarray analysis and verified by qRT-PCR. The protein expression in TGFβ signaling pathways were analyzed by Western Blotting. The relationship between miR-106a-5p and TGFβ were analyzed by luciferase reporter assay. Cell apoptosis were analyzed by flow cytometer. And finally, the metabonomics were analyzed by NMR and multivariate data analysis models (MVDA).. The expression of miR-106a-5p increased in cleft palatal tissue and negatively correlated with the protein level of Tgfbr2. The luciferase assay further proved that the tgfbr2 was a direct target of miR-106a-5p. In another aspect, miR-106a-5p increased apoptosis level in palatal mesenchymal cells, possibly because its inhibition of TGFβ signaling pathway. Moreover, low cholesterol and choline levels with high citric acid and lipid levels were observed by 7T and 9.4T NMR metabonomic analysis, which inferred the disorder of cell membrane synthesis in cleft palate formation. Furthermore, transformation from choline to phosphatidylcholine regulated by miR-106a-5p was also disrupted, resulting in phosphatidic choline synthesis disorder and reduced cell membrane synthesis.. The regulatory mechanism of cleft palate was studied at transcriptional and metabolomics levels, which may provide important information in understanding the primary cause of this abnormality.

Topics: Animals; Apoptosis; Cell Membrane; Citric Acid; Cleft Palate; Disease Models, Animal; Embryo, Mammalian; Female; Gene Expression Regulation, Developmental; Humans; Male; Membrane Lipids; Mesenchymal Stem Cells; Metabolome; Mice; MicroRNAs; Palate; Receptor, Transforming Growth Factor-beta Type II; Signal Transduction; Smad2 Protein; Smad3 Protein; Transcriptome; Transforming Growth Factor beta; Tretinoin

Retinoic acid has been previously proposed in the treatment of Alzheimer's disease (AD). Here, five transgenic mouse models expressing AD and frontotemporal dementia risk genes (i.e., PLB2APP, PLB2TAU, PLB1Double, PLB1Triple, and PLB4) were used to investigate if consistent alterations exist in multiple elements of the retinoic acid signaling pathway in these models. Many steps of the retinoic acid signaling pathway including binding proteins and metabolic enzymes decline, while the previously reported increase in RBP4 was only consistent at late (6 months) but not early (3 month) ages. The retinoic acid receptors were exceptional in their consistent decline in mRNA and protein with transcript decline of retinoic acid receptors β and γ by 3 months, before significant pathology, suggesting involvement in early stages of disease. Decline in RBP1 transcript may also be an early but not late marker of disease. The decline in the retinoic acid signaling system may therefore be a therapeutic target for AD and frontotemporal dementia. Thus, novel stable retinoic acid receptor modulators (RAR-Ms) activating multiple genomic and non-genomic pathways were probed for therapeutic control of gene expression in rat primary hippocampal and cortical cultures. RAR-Ms promoted the non-amyloidogenic pathway, repressed lipopolysaccharide induced inflammatory genes and induced genes with neurotrophic action. RAR-Ms had diverse effects on gene expression allowing particular RAR-Ms to be selected for maximal therapeutic effect. Overall the results demonstrated the early decline of retinoic acid signaling in AD and frontotemporal dementia models and the activity of stable and potent alternatives to retinoic acid as potential therapeutics.

Topics: Alzheimer Disease; Animals; Cerebral Cortex; Disease Models, Animal; Gene Expression; Gene Expression Regulation; Hippocampus; Mice; Mice, Transgenic; Neurons; Rats; Rats, Sprague-Dawley; Receptors, Retinoic Acid; Signal Transduction; Tretinoin

Repair of tissue damaged in diabetic wounds is essential to minimize the cases of amputation of the limbs in millions of diabetic people around the world. Although the all-trans retinoic acid (ATRA) is described as a potential wound healing agent, however its effects are controversial due to adverse reactions that may impair the wound healing during the treatment schedules. Our aim was to design and characterize an ATRA-loaded solid lipid nanoparticles surrounded by chitosan film to promote an ATRA controlled release and to evaluate its effectiveness in promoting wound healing in a diabetic mouse model. The SLN-ATRA were developed using biocompatible lipids without using organic solvent. The SLN-ATRA had high drug entrapment efficiency (98.0 %) and low polydispersity index (PDI) and average diameter, respectively, 0.24 ± 0.02 and 83.0 ± 6 nm. The transmission electron microscope (TEM) image presented that the SLN-ATRA were homogeneous in size and had spherical structures. The incorporation of SLN-ATRA in the chitosan films propitiated a homogeneous distribution of the drug and a controlled drug release. Furthermore, in vivo assay proved that chitosan films containing SLN-ATRA accelerated the closure of wounds of diabetic mice when compared to the control chitosan films without ATRA. SLN-ATRA chitosan films also reduced leukocyte infiltrate in the wound bed, improved collagen deposition, and reduced scar tissue. No sign of skin irritation was observed. These results indicated that SLN-ATRA surrounded in chitosan films are a promising candidate to treat diabetic wounds, improving tissue healing.

Topics: Animals; Chitosan; Diabetes Mellitus, Experimental; Disease Models, Animal; Drug Carriers; Lipids; Male; Mice; Mice, Inbred C57BL; Nanoparticles; Particle Size; Surface Properties; Tretinoin; Wound Healing

Topics: Animals; Antineoplastic Agents; Cancer-Associated Fibroblasts; Cytochrome P450 Family 26; Disease Models, Animal; Drug Resistance, Neoplasm; Humans; Mice; Receptors, Retinoic Acid; Retinoids; Tretinoin; Tumor Microenvironment; Xenograft Model Antitumor Assays

The present study aimed to explore the molecular mechanisms underlying the increase of nicotinamide adenine dinucleotide phosphate:quinine oxidoreductase 1 (NQO1) and γ-glutamylcysteine synthetase (γ-GCS) in brain tissues after intracerebral hemorrhage (ICH). The microglial cells obtained from newborn rats were cultured and then randomly divided into the normal control group (NC group), model control group (MC group), rosiglitazone (RSG) intervention group (RSG group), retinoic-acid intervention group (RSG+RA group), and sulforaphane group (RSG+SF group). The expression levels of NQO1, γ-GCS, and nuclear factor E2-related factor 2 (Nrf2) were measured by real-time polymerase chain reaction (RT-PCR) and Western blotting, respectively. The results showed that the levels of NQO1, γ-GCS and Nrf2 were significantly increased in the MC group and the RSG group as compared with those in the NC group (P<0.01). They were found to be markedly decreased in the RSG+RA group and increased in the RSG+SF group when compared with those in the MC group or the RSG group (P<0.01). The RSG+SF group displayed the highest levels of NQO1, γ-GCS, and Nrf2 among the five groups. In conclusion, a medium dose of RSG increased the anti-oxidative ability of thrombin-activated microglia by increasing the expression of NQO1 and γ-GCS. The molecular mechanisms underlying the increase of NQO1 and γ-GCS in thrombin-activated microglia may be associated with the activation of Nrf2.

Topics: Animals; Animals, Newborn; Cells, Cultured; Cerebral Hemorrhage; Disease Models, Animal; Female; Glutamate-Cysteine Ligase; Isothiocyanates; Male; Microglia; NAD(P)H Dehydrogenase (Quinone); NF-E2-Related Factor 2; PPAR gamma; Primary Cell Culture; Rats; Rats, Sprague-Dawley; Rosiglitazone; Sulfoxides; Thrombin; Tretinoin

Previous studies have shown that rambutan peel phenolic (RPP) extract has excellent biological activities due to its abundant phenolic content and profile. In this study, the potential anti-osteoporosis (OP) effects of RPP were evaluated by suppressing receptor activator nuclear factor-kappa B ligand (RANKL)-induced differentiation of RAW264.7 cells into osteoclasts and amelioratingretinoic acid-induced OP in rats. Our results showed that RPP efficiently decreased the formation of tartrate-resistant acid phosphatase (TRAP)-positive cells and reduced total TRAP activity in RAW264.7 cells under RANKL stimulation. RPP treatment significantlyameliorated retinoid acid-induced calcium loss in rats (

Topics: Animals; Biomarkers; Biopsy; Body Weight; Bone Density; Cell Differentiation; Cell Survival; Disease Models, Animal; Immunohistochemistry; Mice; Osteoclasts; Osteogenesis; Osteoporosis; Phenols; Plant Extracts; RANK Ligand; Rats; RAW 264.7 Cells; Sapindaceae; Tretinoin

To explore the role of all-trans retinoic acid (ATRA) in renal ischemia/reperfusion injury of diabetic rats.. Sixty adult male rats were randomly divided into 6 groups, including sham group (S group), ischemia-reperfusion group (I/R group), ischemia-reperfusion+ATRA group (A group), diabetic group (D group), diabetic ischemia-reperfusion group (DI/R group), diabetic ischemia-reperfusion +ATRA group (DA group). The levels of creatinine (Cr), cystatin C (Cys-C) and β2-microglobulin (β2-MG) were measured. Morphology of renal tissue was observed under light microscope.. DJ-1, Nrf2, HO-1 and caspase-3 were detected by western blot. DJ-1, Nrf2, HO-1 and caspase-3 in I/R group, D group and DI/R group was higher than that in S group. Compared with I/R group, Nrf2 and HO-1 in A group was decreased, but caspase-3 was increased. However, Nrf2 in DA group was higher than that in DI/R group, HO-1 and caspase-3 in DA group were lower than that in DI/R group. Compared with group S, Cr, Cys-C and β2-MG in I/R group, A group, D group, and DI/R group were higher. Whereas the levels of Cr, Cys-C, β2-MG and renal injury score in DA group were lower than those in DI/R group.. ATRA has a protective effect on renal ischemia-reperfusion injury in diabetic rats, maybe relating to DJ/Nrf2 pathway.

Topics: Animals; Diabetes Mellitus, Experimental; Disease Models, Animal; Drug Evaluation, Preclinical; Kidney; Male; NF-E2-Related Factor 2; Rats; Reperfusion Injury; Streptozocin; Tretinoin

Pt-ATRA, a carboplatin analogue containing an all-trans retinoic acid (ATRA) derivative ligand, was synthesized via a click reaction. Upon cellular internalization, Pt-ATRA exhibits a dual function, releasing an active Pt(ii) moiety to induce cell apoptosis and ATRA to inhibit tumor metastasis.

Topics: Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Carboplatin; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Ligands; Mice; Molecular Structure; Neoplastic Stem Cells; Structure-Activity Relationship; Tretinoin

Growing evidence suggests an adverse impact of gut microbiota dysbiosis on human health. However, it remains unclear whether embryonic osteogenesis is affected by maternal gut dysbacteriosis. In this study, we observed that elevated lipopolysaccharide (LPS) levels led to skeletal developmental retardation in an established mouse model of gut microbiota dysbiosis. Using chick embryos exposed to dysbacteriosis-derived LPS, we found restriction in the development of long bones as demonstrated by Alcian blue and alizarin red staining. Micro-CT and histological analysis exhibited decreased trabecular volume, bone mineral density, and collagen production, as well as suppressed osteoblastic gene expression (

Topics: Animals; Bone Diseases, Metabolic; Cell Line; Chick Embryo; Disease Models, Animal; Dysbiosis; Ectoderm; Female; Homeodomain Proteins; Lipopolysaccharides; Mice; Sequence Analysis, RNA; Tretinoin

We previously showed that all-

Topics: Animals; Bacterial Translocation; Contraindications, Drug; Dendritic Cells; Disease Models, Animal; Disease Progression; Drug Administration Schedule; Drug Synergism; Dysbiosis; Female; Gastrointestinal Microbiome; Gene Expression Regulation; Glomerulonephritis; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Lupus Nephritis; Mice; Mice, Inbred BALB C; Real-Time Polymerase Chain Reaction; RNA; RNA-Seq; Specific Pathogen-Free Organisms; Spleen; Terpenes; Tretinoin; Vitamin A

Psoriasis is a chronic immune-mediated inflammatory skin disease without effective treatment. The utilization of all trans-retinoic acid (TRA) and betamethasone (BT) for the treatment of psoriasis is still facing difficulties, due to their relatively poor stability, limited skin permeation, and systemic side effects. Flexible liposomes are excellent in deeper skin permeation and reducing the side effects of drugs, which is promising for effective treatment of skin disorders. This work aimed to establish dual-loaded flexible liposomal gel for enhanced therapeutic efficiency of psoriasis based on TRA and BT.. Flexible liposomes co-loaded with TRA and BT were successfully prepared in our study. The characterization examination revealed that flexible liposomes featured nano-sized particles (around 70 nm), high drug encapsulation efficiency (> 98%) and sustained drug release behaviors. Flexible liposomes remarkably increased the drug skin permeation and retention as compared with free drugs. Results on HaCaT cells suggested that flexible liposomes were nontoxic, and its cellular uptake has a time-dependent manner. In vivo studies suggested the topical application of TRA and BT dual-loaded liposomal gel had the best ability to reduce the thickness of epidermal and the level of cytokines (TNF-α and IL-6), largely alleviating the symptoms of psoriasis.. Flexible liposomal gel dual-loaded with TRA and BT exerted a synergistic effect, which is a promising topical therapeutic for the treatment of psoriasis.

Topics: Animals; Betamethasone; Cell Survival; Cytokines; Dermatologic Agents; Disease Models, Animal; Gels; HaCaT Cells; Humans; Liposomes; Mice, Inbred BALB C; Particle Size; Pliability; Psoriasis; Rats; Rats, Sprague-Dawley; Tretinoin

All-trans retinoic acid (ATRA), a ligand of retinoic acid receptors, could regulate various biological processes by activating retinoic acid signals. Recent studies suggested that ATRA displays multiple neuroprotective effects and thereby alleviates the disease progression in a variety of neurological diseases. Our previous studies found that the impaired retinoic acid signal decreased ALDH1A2, an essential synthetase of ATRA, in the spinal cord of ALS mice. Here, we evaluated the neuroprotective and neurorestorative effects of ATRA in a SOD1-G93A transgenic mice model of ALS. We administrated ATRA(3 mg/kg) daily from the onset stage to the progression stage for 5 weeks. Behavioral tests showed that ATRA improved the forelimb grip strength in ALS mice and may slow the disease progression, but not the body weight. ATRA could completely reverse the impaired retinoic acid receptor alpha (RARα) signal in the spinal cord of ALS mice. This effect was accompanied by enhancing the degradation of misfolded proteins via the ubiquitin-proteasome system, regulating the oxidative stress, inhibiting the astrocyte activation, and promoting the neurotrophic signal recovery. Our findings are the first to indicate that the damaged retinoic acid signal is involved in the pathogenesis of ALS, and ATRA could induce the functional neuroprotection via repairing the damaged retinoic acid signal.

Topics: Amyotrophic Lateral Sclerosis; Animals; Astrocytes; Disease Models, Animal; Disease Progression; Mice; Mice, Transgenic; Motor Neurons; Neuroprotective Agents; Superoxide Dismutase; Tretinoin

To determine whether all-trans retinoic acid (ATRA) can influence the development of Angiotensin II (Ang II) induced experimental abdominal aortic aneurysms (AAAs).. Apolipoprotein E knock-out (ApoE. The abdominal aortic diameter was significantly reduced in the ATRA group compared with the AAA group (3 of 12 (25%) vs 9 of 12 (75%), P < 0.05), and the ATRA group exhibited reduced blood pressure on days 7, 14, and 28. Low expression of angiotensin II receptor type 1 (AT1), matrix metalloproteinase 2 (MMP2), and matrix metalloproteinase 9 (MMP9) and EVG staining revealed a significant reduction in the disruption of elastic fibers in the abdominal aortic tissue of the ATRA group compared to the AAA group. Western blot analysis indicated that protein levels of retinoic acid receptor α (RARα), MMP2, MMP9, and AT1 were dramatically affected by ATRA treatment.. In conclusion, ATRA attenuates the progression of Ang II-induced AAAs, possibly by downregulating MMP2, MMP9, and AT-1 expression.

Topics: Angiotensin II; Animals; Aortic Aneurysm, Abdominal; Disease Models, Animal; Disease Progression; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Mice, Knockout, ApoE; Tretinoin

More and more people are suffering from depression in modern society. It is believed that the development of depression results from alterations in synaptic transmission, especially in the hippocampus. Animal experiments and clinical studies have demonstrated that retinoids are essential components in hippocampal synaptic plasticity, and they have a close relationship with depression. However, it is still unclear how excessive retinoic acid (RA) causes depression and what synaptic and molecular mechanisms underlie it.. Behavioral, electrophysiological, and molecular approaches were employed to characterize the effects of RA on depression and synaptic plasticity. RA was continuously administered intracerebroventricularly through an osmotic pump.. RA treatment induced depression-like behaviors, as evidenced by decreased sucrose preference and increased immobile duration in both the forced swim test and the tail suspension test. RA administration also induced anxiety-like behaviors, indicated by decreased duration in the open arms of the elevated plus maze and the central of the open field. RA treatment decreased the neuronal excitability of the hippocampus either by changing the excitatory/inhibitory receptor balance or by promoting the synthesis of inhibitory neurotransmitters. Moreover, long-term potentiation was decreased in both the excitatory postsynaptic potential and the population spike in RA-treated rats, presumably a consequence of the reduced glur1 transcript level.. The mechanism of how excess RA affects the hippocampal gene expression and synaptic plasticity requires further study.. RA treatment can induce depression-like behavior in rats and impair hippocampal plasticity. Thus, improving synaptic plasticity in the hippocampus may ameliorate the affective disorders caused by excessive RA.

Topics: Animals; Depression; Disease Models, Animal; Hippocampus; Neuronal Plasticity; Rats; Synaptic Transmission; Tretinoin

Osteoporosis (OP) is a metabolic bone disease in which that volume of bone tissue per unit volume decrease, which is a common disease disturbing the elderly or postmenopausal women. Rhizoma Drynariae (RD) is a kind of herb widely used in thousands of years of clinical practice in China to tonify kidney and prevent osteoporosis, with reliable curative effect. However, the mechanism of its anti-osteoporosis action is still unclear. This study is dedicated to exploration the therapeutic effect of RD on retinoic acid solution-induced OP model rats based on high-throughput metabolomics technology platform, and reveal its influence on metabolomics level, so as to find effective potential biomarkers and therapeutic targets for diagnosing OP. OP model was established by intragastric administration of retinoic acid solution for 21 days, and then the treatment group was treated by intragastric administration of RD solution for 60 days. Blood samples of all groups were collected and analyzed based on UPLC-MS metabolomics and combined with EZinfo 3.0 data analysis, 32 potential biomarkers were identified, including 22 in ESI+ and 10 in ESI-, these biomarkers are related to 9 metabolic pathways. After treatment with RD solution, 21 biomarkers were obviously regulated, these mainly affected linoleic acid metabolic, glycerophospholipid metabolism and arachidonic acid metabolism pathway. The results show that RD can reduce the risk of OP disease, which may be related to the metabolic pathway mentioned above, and provides the foundation for the administer prophylaxis and treatment of OP with natural products.

Topics: Animals; Biomarkers; Chromatography, High Pressure Liquid; Disease Models, Animal; Drugs, Chinese Herbal; Female; Mass Spectrometry; Metabolome; Metabolomics; Osteoporosis; Polypodiaceae; Protective Agents; Rats, Sprague-Dawley; Rhizome; Tretinoin

BACKGROUND Rheumatoid arthritis (RA) is an inflammatory disorder that is present in approximately 1% of the world's population. This study was aimed to investigate the effect of retinoic acid-platinum (II) complex [RT-Pt(II)] on rheumatoid arthritis (RA) and to explore the mechanism involved. MATERIAL AND METHODS MH7A cell viability was determined by MTT assay and apoptosis was assessed using FACSCalibur flow cytometry. RT-PCR and Western blot assays were used for assessment of mRNA and proteins levels. RESULTS Treatment of rheumatoid arthritis with RT-Pt(II) significantly reduced the levels of IL‑1ß, IL-6, IL-8, MMP-1, and MMP-13 in synovial fluid of mice in a dose-dependent manner. The expression of iNOS and COX-2 mRNA and protein in rheumatoid arthritis rats was also significantly inhibited by treatment with RT-Pt(II). The TNF-alpha-induced proliferation of MH7A cells was alleviated by RT-Pt(II) treatment in a concentration-dependent manner. Moreover, RT-Pt(II) treatment induced apoptosis and caused arrest of cell cycle in MH7A cells. The activation of MEK/NF-kappaB pathway was downregulated by RT-Pt(II) treatment in MH7A cells. CONCLUSIONS In summary, the present study demonstrated that RT-Pt(II) inhibits TNF-alpha-induced inflammatory response, suppresses cell viability, and induces apoptosis in rheumatoid arthritis synovial cells. Moreover, RT-Pt(II) exhibited its effect through targeting the MEK/NF-kappaB pathway. Therefore, RT-Pt(II) can be used for the development of treatments for rheumatoid arthritis.

Topics: Animals; Antirheumatic Agents; Apoptosis; Arthritis, Rheumatoid; Cell Line; Coordination Complexes; Cyclooxygenase 2; Disease Models, Animal; Gene Expression Regulation; Humans; Interleukin-1beta; Interleukin-6; Interleukin-8; Male; Matrix Metalloproteinase 13; Mice; Mitogen-Activated Protein Kinase Kinases; NF-kappa B; Nitric Oxide Synthase Type II; Platinum Compounds; Rats; Rats, Sprague-Dawley; Signal Transduction; Synovial Fluid; Synoviocytes; Tretinoin; Tumor Necrosis Factor-alpha

Effectiveness of retinoic acid (RA) in treating food allergy is not yet clear. Using an allergic mouse model, we examined the amelioration of the severity of food allergy by daily RA intake with allergen or without. Female Balb/c mice were systemically sensitized to egg white (EW) and alum by intraperitoneal injection. Sensitized mice were provided diets supplemented with 0% (non-treated group), 0.1% EW (allergen group), 0.0017% RA (RA group), or 0.1% EW plus 0.0017% RA (RA+allergen group) with 20% casein for 4 wk. Oral food challenge (OFC) and allergic biomarkers were quantified. The decrease in rectal temperature post-OFC was significantly suppressed in the RA and RA+allergen groups compared to those in the non-treated and allergen groups, respectivety. The plasma levels of ovalbumin-specific IgE, IgA and IgG1 at the study endpoint were higher in the allergen and RA+allergen groups than those in the non-treated and RA+allergen groups, respectivety. Plasma ovalbumin-specific IgG2a levels at the study endpoint were significantly higher in the RA+allergen group than those in the RA groups. The supernatant concentrations of interleukin-10 and interferon-γ in the cultured spleen lymphocytes were highest in the RA+allergen group compared to those in the other groups. Thus, continuous intake of RA under allergen exposure ameliorated the severity of food allergy in a mouse model with food allergy.

Topics: Allergens; Animals; Body Temperature; Dietary Supplements; Disease Models, Animal; Egg Hypersensitivity; Egg White; Female; Food Hypersensitivity; Immunoglobulin A; Immunoglobulin E; Immunoglobulin G; Interferon-gamma; Interleukin-10; Lymphocytes; Mice; Mice, Inbred BALB C; Ovalbumin; Tretinoin

Genetic hearing loss is a common health problem with no effective therapy currently available. DFNA15, caused by mutations of the transcription factor POU4F3, is one of the most common forms of autosomal dominant non-syndromic deafness. In this study, we established a novel mouse model of the human DFNA15 deafness, with a Pou4f3 gene mutation (Pou4f3Δ) identical to that found in a familial case of DFNA15. The Pou4f3(Δ/+) mice suffered progressive deafness in a similar manner to the DFNA15 patients. Hair cells in the Pou4f3(Δ/+) cochlea displayed significant stereociliary and mitochondrial pathologies, with apparent loss of outer hair cells. Progression of hearing and outer hair cell loss of the Pou4f3(Δ/+) mice was significantly modified by other genetic and environmental factors. Using Pou4f3(-/+) heterozygous knockout mice, we also showed that DFNA15 is likely caused by haploinsufficiency of the Pou4f3 gene. Importantly, inhibition of retinoic acid signaling by the aldehyde dehydrogenase (Aldh) and retinoic acid receptor inhibitors promoted Pou4f3 expression in the cochlear tissue and suppressed the progression of hearing loss in the mutant mice. These data demonstrate Pou4f3 haploinsufficiency as the main underlying cause of human DFNA15 deafness and highlight the therapeutic potential of Aldh inhibitors for treatment of progressive hearing loss.

Topics: Aldehyde Dehydrogenase; Animals; Benzaldehydes; Disease Models, Animal; Enzyme Inhibitors; Hair Cells, Auditory; Haploinsufficiency; Hearing Loss; Homeodomain Proteins; Humans; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Knockout; Noise; para-Aminobenzoates; Quinolines; Transcription Factor Brn-3C; Tretinoin

Dietary obesity is regarded as a problem worldwide, and it has been revealed the strong linkage between obesity and allergic inflammation. Fatty acid-binding protein 5 (FABP5) is expressed in lung cells, such as alveolar epithelial cells (ECs) and alveolar macrophages, and plays an important role in infectious lung inflammation. However, we do not know precise mechanisms on how lipid metabolic change in the lung affects allergic lung inflammation. In this study, we showed that Fabp5

Topics: Alveolar Epithelial Cells; Animals; Asthma; Diet, High-Fat; Disease Models, Animal; Fatty Acid-Binding Proteins; Gene Expression; Inflammation; Interleukin-1 Receptor-Like 1 Protein; Lipid Metabolism; Lung; Lymphocytes; Mice, Inbred C57BL; Molecular Targeted Therapy; Neoplasm Proteins; Obesity; Tretinoin

The main goal of the present study is to investigate the effects of retinoic acid and fibroblast growth factor-2 on serum levels of FSH and LH, histology, and apoptosis in the mouse model of Poly Cystic Ovary Syndrome (PCOS).. 80 female NMRI mice have been randomly divided into eight groups. Group 1 received normal saline as a control, and Group 2 received estradiol valerate (EV) at 4 mg/100 g of body weight. Moreover, Groups 3-4 were administered with RA (a dose of 0.05 μg/μl) and FGF2 (a dose of 0.01 μg/kg), respectively. Groups 5 and 6 respectively received the EV plus the RA (0.05 μg/μl) and FGF2 (0.01 μg/kg). Group 7 received the RA and FGF2 at doses corresponding to healthy mice, and Group 8 received the EV plus the RA + FGF2 (similar to previous doses). RA and FGF2 were injected three times per week for four weeks. Finally, histological and immunohistological parameters of the ovary were evaluated.. The study revealed that both single and combined injection of fibroblast growth factor-2 (FGF2) and retinoic acid (RA) in groups 5, 6, and 8 significantly reduced follicular diameters compared to group 2. Measurements confirmed that simultaneous injection of RA and FGF2 into polycystic mice significantly increased antral follicles, corpus luteum (CL), epithelial thickness, and oocyte diameter as well as decreased cystic follicles. Positive TUNEL cells that were considerably increased in the antral follicle of group 2 significantly decreased in the RA and FGF2 recipient groups, either alone or in combination. Besides, the injection of FGF2 increased preantral follicles and CL.. The findings of the present investigation reveal that injection of RA and FGF2 has both protective and ameliorative effects that can promise new therapies for women with PCOS.

Topics: Animals; Apoptosis; Corpus Luteum; Disease Models, Animal; Estradiol; Female; Fibroblast Growth Factor 2; Follicle Stimulating Hormone; Injections, Intraperitoneal; Luteinizing Hormone; Mice; Oocytes; Ovarian Follicle; Polycystic Ovary Syndrome; Protective Agents; Tretinoin

There is a major clinical need for new therapies for the treatment of chronic itch. Many of the molecular components involved in itch neurotransmission are known, including the neuropeptide NPPB, a transmitter required for normal itch responses to multiple pruritogens in mice. Here, we investigated the potential for a novel strategy for the treatment of itch that involves the inhibition of the NPPB receptor NPR1 (natriuretic peptide receptor 1). Because there are no available effective human NPR1 (hNPR1) antagonists, we performed a high-throughput cell-based screen and identified 15 small-molecule hNPR1 inhibitors. Using in vitro assays, we demonstrated that these compounds specifically inhibit hNPR1 and murine NPR1 (mNPR1). In vivo, NPR1 antagonism attenuated behavioral responses to both acute itch- and chronic itch-challenged mice. Together, our results suggest that inhibiting NPR1 might be an effective strategy for treating acute and chronic itch.

Topics: Animals; Behavior, Animal; Cell-Free System; Dermatitis, Contact; Disease Models, Animal; Ganglia, Spinal; Humans; Mice, Inbred C57BL; Mice, Knockout; Neurons; Pruritus; Receptors, Atrial Natriuretic Factor; Reproducibility of Results; Signal Transduction; Small Molecule Libraries

Human adipose-derived stem cells (hADSCs) are increasingly presumed to be a prospective stem cell source for cell replacement therapy in various degenerative and/or traumatic diseases. The potential of trans-differentiating hADSCs into motor neuron cells indisputably provides an alternative way for spinal cord injury (SCI) treatment. In the present study, a stepwise and efficient hADSC trans-differentiation protocol with retinoic acid (RA), sonic hedgehog (SHH), and neurotrophic factors were developed. With this protocol hADSCs could be converted into electrophysiologically active motoneuron-like cells (hADSC-MNs), which expressed both a cohort of pan neuronal markers and motor neuron specific markers. Moreover, after being primed for neuronal differentiation with RA/SHH, hADSCs were transplanted into SCI mouse model and they survived, migrated, and integrated into injured site and led to partial functional recovery of SCI mice. When ablating the transplanted hADSC-MNs harboring HSV-TK-mCherry overexpression system with antivirial Ganciclovir (GCV), functional relapse was detected by motor-evoked potential (MEP) and BMS assays, implying that transplanted hADSC-MNs participated in rebuilding the neural circuits, which was further confirmed by retrograde neuronal tracing system (WGA). GFP-labeled hADSC-MNs were subjected to whole-cell patch-clamp recording in acute spinal cord slice preparation and both action potentials and synaptic activities were recorded, which further confirmed that those pre-conditioned hADSCs indeed became functionally active neurons in vivo. As well, transplanted hADSC-MNs largely prevented the formation of injury-induced cavities and exerted obvious immune-suppression effect as revealed by preventing astrocyte reactivation and favoring the secretion of a spectrum of anti-inflammatory cytokines and chemokines. Our work suggests that hADSCs can be readily transformed into MNs in vitro, and stay viable in spinal cord of the SCI mouse and exert multi-therapeutic effects by rebuilding the broken circuitry and optimizing the microenvironment through immunosuppression.

Topics: Animals; Cell Differentiation; Cell Transdifferentiation; Disease Models, Animal; Hedgehog Proteins; Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Motor Neurons; Nerve Growth Factors; Spinal Cord Injuries; Tretinoin

Cleft palate(CP) is a widely studied congenital malformation. However, its etiology and pathogenesis still remain unclear. Proteins are fundamental molecules that participate in every biological process within cells. In this study, we established CP mouse models induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and retinoic acid (RA), using proteomics technology isobaric tags for relative and absolute quantitation (iTRAQ) to investigate the key proteins in the formation of CP. Pregnant mice were given a gavage of TCDD 28μg/kg or retinoic acid 80mg/kg of body weight or equivalent corn oil at gestational day 10.5(GD10.5) and sacrificed at GD 17.5. Foetal mice were recorded and collected for further detection. Western blot was performed to verify the iTRAQ results. Eventually, we obtained 18 common differentially expressed proteins in TCDD group and RA group compared with normal control, 17 up-regulated and 1 down-regulated. 14-3-3sigma and Annexin A1 were up-regulated in experimental groups at GD17.5, which was consistent with Western blot. We speculated that the common differentially expressed proteins might be one of the molecular mechanisms in the formation of cleft palate.

Topics: 14-3-3 Proteins; Animals; Annexin A1; Cleft Palate; Disease Models, Animal; Female; Male; Mice, Inbred C57BL; Polychlorinated Dibenzodioxins; Proteomics; Tretinoin

Ecotropic virus integration site 1 (EVI1), whose overexpression characterizes a particularly aggressive subtype of acute myeloid leukemia (AML), enhanced anti-leukemic activities of all-trans retinoic acid (atRA) in cell lines and patient samples. However, the drivers of leukemia formation, therapy resistance, and relapse are leukemic stem cells (LSCs), whose properties were hardly reflected in these experimental setups. The present study was designed to address the effects of, and interactions between, EVI1 and retinoids in AML LSCs. We report that Evi1 reduced the maturation of leukemic cells and promoted the abundance, quiescence, and activity of LSCs in an MLL-AF9-driven mouse model of AML. atRA further augmented these effects in an Evi1 dependent manner. EVI1 also strongly enhanced atRA regulated gene transcription in LSC enriched cells. One of their jointly regulated targets, Notch4, was an important mediator of their effects on leukemic stemness. In vitro exposure of leukemic cells to a pan-RAR antagonist caused effects opposite to those of atRA. In vivo antagonist treatment delayed leukemogenesis and reduced LSC abundance, quiescence, and activity in Evi1

Topics: Animals; Apoptosis; Carcinogenesis; Cell Proliferation; Disease Models, Animal; Gene Expression Regulation, Leukemic; Humans; Leukemia, Myeloid, Acute; MDS1 and EVI1 Complex Locus Protein; Mice; Myeloid Cells; Neoplastic Stem Cells; Receptor, Notch4; Tretinoin

Neural tube defects (NTDs) are severe, common birth defects that result from failure of normal neural tube closure during early embryogenesis. Accumulating strong evidence indicates that genetic factors contribute to NTDs etiology, among them, HOX genes play a key role in neural tube closure. Although abnormal HOX gene expression can lead to NTDs, the underlying pathological mechanisms have not fully been understood.. We detected that H3K27me3 and expression of the Hox genes in a retinoic acid (RA) induced mouse NTDs model on E8.5, E9.5 and E10.5 using RNA-sequencing and chromatin immunoprecipitation sequencing assays. Furthermore, we quantified 10 Hox genes using NanoString nCounter in brain tissue of fetuses with 39 NTDs patients including anencephaly, spina bifida, hydrocephaly and encephalocele.. Here, our results showed differential expression in 26 genes with a > 20-fold change in the level of expression, including 10 upregulated Hox genes. RT-qPCR revealed that these 10 Hox genes were all upregulated in RA-induced mouse NTDs as well as RA-treated embryonic stem cells (ESCs). Using ChIP-seq assays, we demonstrate that a decrease in H3K27me3 level upregulates the expression of Hox cluster A-D in RA-induced mouse NTDs model on E10.5. Interestingly, RA treatment led to attenuation of H3K27me3 due to cooperate between UTX and Suz12, affecting Hox gene regulation. Further analysis, in human anencephaly cases, upregulation of 10 HOX genes was observed, along with aberrant levels of H3K27me3. Notably, HOXB4, HOXC4 and HOXD1 expression was negatively correlated with H3K27me3 levels.. Our results indicate that abnormal HOX gene expression induced by aberrant H3K27me3 levels may be a risk factor for NTDs and highlight the need for further analysis of genome-wide epigenetic modification in NTDs.

Topics: Anencephaly; Animals; Disease Models, Animal; Embryonic Stem Cells; Histone Demethylases; Histones; Homeodomain Proteins; Humans; Mice; Mice, Inbred C57BL; Neural Tube Defects; Polycomb Repressive Complex 2; RNA Interference; RNA, Small Interfering; Tretinoin; Up-Regulation

The accumulation of prostaglandin E2 (PGE

Topics: Adenocarcinoma; Aldehyde Dehydrogenase 1 Family; Animals; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Proliferation; Dinoprostone; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Humans; Hydroxyprostaglandin Dehydrogenases; Inflammation; Isoenzymes; Mice; Neoplastic Stem Cells; Pancreas; Proto-Oncogene Proteins p21(ras); Retinal Dehydrogenase; Retinoic Acid 4-Hydroxylase; Tretinoin

Myelomeningocele (MMC) is a devastating congenital neural tube defect that results in the exposure of spinal cord to the intrauterine environment, leading to secondary spinal cord injury and severe impairment. Although the mechanisms underlying the secondary pathogenesis are clinically relevant, the exact cause of

Topics: Amniotic Fluid; Animals; Disease Models, Animal; Hyaluronic Acid; Meningomyelocele; Rats; Tretinoin

Ending the tuberculosis (TB) epidemic by 2030 was recently listed in the United Nations (UN) Sustainable Development Goals alongside HIV/AIDS and malaria as it continues to be a major cause of death worldwide. With a significant proportion of TB cases caused by resistant strains of Mycobacterium tuberculosis (Mtb), there is an urgent need to develop new and innovative approaches to treatment. Since 1989, researchers have been assessing the anti-bacterial effects of the active metabolite of vitamin A, all trans-Retinoic acid (ATRA) solution, in Mtb models. More recently the antibacterial effect of ATRA has been shown to regulate the immune response to infection via critical gene expression, monocyte activation and the induction of autophagy leading to its application as a host-directed therapy (HDT). Inhalation is an attractive route for targeted treatment of TB, and therefore we have developed ATRA-loaded microparticles (ATRA-MP) within the inhalable size range (2.07 ± 0.5 µm) offering targeted delivery of the encapsulated cargo (70.5 ± 2.3%) to the site of action within the alveolar macrophage, which was confirmed by confocal microscopy. Efficient cellular delivery of ATRA was followed by a reduction in Mtb growth (H37Ra) in THP-1 derived macrophages evaluated by both the BACT/ALERT® system and enumeration of colony forming units (CFU). The antibacterial effect of ATRA-MP treatment was further assessed in BALB/c mice infected with the virulent strain of Mtb (H37Rv). ATRA-MP treatments significantly decreased the bacterial burden in the lungs alongside a reduction in pulmonary pathology following just three doses administered intratracheally. The immunomodulatory effects of targeted ATRA treatment in the lungs indicate a distinct yet effective mechanism of action amongst the formulations. This is the first study to-date of a controlled release ATRA treatment for TB suitable for inhalation that offers improved targeting of a HDT, retains antibacterial efficacy and improves pulmonary pathology compared to ATRA solution.

Topics: Administration, Inhalation; Animals; Antitubercular Agents; Delayed-Action Preparations; Disease Models, Animal; Drug Carriers; Drug Compounding; Drug Liberation; Female; Humans; Macrophages, Alveolar; Mice; Mice, Inbred BALB C; Mycobacterium tuberculosis; Particle Size; Polylactic Acid-Polyglycolic Acid Copolymer; Pulmonary Alveoli; THP-1 Cells; Treatment Outcome; Tretinoin; Tuberculosis, Pulmonary

Craniosynostosis (CS), the premature and pathological fusion of cranial sutures, is a relatively common developmental disorder. Elucidation of the pathways involved and thus therapeutically targeting it would be promising for the prevention of CS. In the present study, we examined the role of BMP pathway in the all-trans retinoic acid (atRA)-induced CS model and tried to target the pathway in vivo via PLGA-based control release. As expected, the posterior frontal suture was found to fuse prematurely in the atRA subcutaneous injection mouse model. Further mechanism study revealed that atRA could repress the proliferation while promote the osteogenic differentiation of suture-derived mesenchymal cells (SMCs). Moreover, BMP signal pathway was found to be activated by atRA, as seen from increased expression of BMPR-2 and pSMAD1/5/9. Recombinant mouse Noggin blocked the atRA-induced enhancement of osteogenesis of SMCs in vitro. In vivo, PLGA microsphere encapsulated with Noggin significantly prevented the atRA-induced suture fusion. Collectively, these data support the hypothesis that BMP signaling is involved in retinoic acid-induced premature fusion of cranial sutures, while PLGA microsphere-based control release of Noggin emerges as a promising strategy for prevention of atRA-induced suture fusion.

Topics: Animals; Animals, Newborn; Biocompatible Materials; Bone Morphogenetic Proteins; Carrier Proteins; Cell Proliferation; Cranial Sutures; Craniosynostoses; Disease Models, Animal; Drug Carriers; Drug Liberation; Injections, Subcutaneous; Mesenchymal Stem Cells; Mice, Inbred C57BL; Osteogenesis; Polylactic Acid-Polyglycolic Acid Copolymer; Tretinoin

Fluconazole-induced alopecia is a significant problem for patients receiving long-term therapy. We evaluated the hair cycle changes of fluconazole in a rat model and investigated potential molecular mechanisms. Plasma and tissue levels of retinoic acid were not found to be causal. Human patients with alopecia attributed to fluconazole also underwent detailed assessment and in both our murine model and human cohort fluconazole induced telogen effluvium. Future work further examining the mechanism of fluconazole-induced alopecia should be undertaken.

Topics: Alopecia Areata; Animals; Antifungal Agents; Disease Models, Animal; Fluconazole; Humans; Male; Mice; Rats; Rats, Wistar; Tretinoin

Targeting the specific molecular proteins or genes which are responsible for the suppression of cancer growth is currently an emerging molecular method to treat cancer. ATRA treatment is now considered as a molecular targeted therapy for many cancers. As ATRA exhibits its therapeutic effect through its receptors, this study was focused to investigate the effect and action of liposomal-ATRA treatment on the expression of RAR-β protein which is also a tumor suppressor. The liposomal-ATRA was developed with cationic DOTAP and cholesterol by thin-film formation method. The benzo(a)pyrene(50 mg/kg b.wt)-induced mice were treated with free and liposomal-ATRA(0.60 mg/kg b.wt). The RAR-β protein expression in lung and liver tissue samples were analyzed by immunohistochemistry (IHC) and western blotting (WB) on the 30th and 120th days. Almost nil expression of RAR-β protein was observed in B(a)P cancer control and liposome alone-treated groups. A comparatively elevated expression was seen in the free ATRA-treated group (IHC score-2+ in lung on the 120th day with band density of 14.46 ± 1.24% in WB). Interestingly, the liposomal-ATRA treatment demonstrated a significantly (p ≤ 0.01) higher RAR-β expression in lung (35.20 ± 3.398% band intensity and score 4+ in the 120th day) than that of in ATRA alone treatment. This study results indicate that the RAR-β protein expression was suppressed by B(a)P during cancer induction even on the 30th day itself. The treatment could reactivate the suppression and the lipo-ATRA treatment could show significantly higher RAR-β expression on the 120th day, which implies that it accumulated more ATRA in target site and sustained it for enhanced action.

Topics: Animals; Antineoplastic Agents; Benzo(a)pyrene; Cholesterol; Disease Models, Animal; Fatty Acids, Monounsaturated; Liposomes; Liver; Lung; Lung Neoplasms; Male; Mice; Quaternary Ammonium Compounds; Receptors, Retinoic Acid; Tretinoin

Cardiac malformations (CVMs) are a leading cause of infant morbidity and mortality. CVMs are particularly prevalent when the developing fetus is exposed to high levels of phenylalanine in-utero in mothers with Phenylketonuria. Yet, elucidating the underlying molecular mechanism leading to CVMs has proven difficult. In this study we used RNA-Seq to investigate an avian model of MPKU and establish differential gene expression (DEG) characteristics of the early developmental stages HH10, 12, and 14. In total, we identified 633 significantly differentially expressed genes across stages HH10, 12, and 14. As expected, functional annotation of significant DEGs identified associations seen in clinical phenotypes of MPKU including CVMs, congenital heart defects, craniofacial anomalies, central nervous system defects, and growth anomalies. Additionally, there was an overrepresentation of genes involved in cardiac muscle contraction, adrenergic signaling in cardiomyocytes, migration, proliferation, metabolism, and cell survival. Strikingly, we identified significant changes in expression with multiple genes involved in Retinoic Acid (RA) metabolism and downstream targets. Using qRTPCR, we validated these findings and identified a total of 42 genes within the RA pathway that are differentially expressed. Here, we report the first elucidation of the molecular mechanisms of cardiovascular malformations in MPKU conducted at early developmental timepoints. We provide evidence suggesting a link between PHE exposure and the alteration of RA pathway. These results are promising and offer novel findings associated with congenital heart defects in MPKU.

Topics: Animals; Chickens; Disease Models, Animal; Female; Heart Defects, Congenital; Metabolic Networks and Pathways; Phenotype; Phenylalanine; Phenylketonuria, Maternal; Pregnancy; Sequence Analysis, RNA; Transcriptome; Tretinoin; Zygote

Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end-stage renal disease in children. Our group has discovered that Holliday Junction resolvase gene Gen1 is a potential candidate gene for CAKUT. Gen1 mutant mice showed CAKUT phenotypes similar to those observed in retinoic acid (RA)-deficient models. The expression of Raldh2, which encodes the key enzyme in RA synthesis, was reduced in Gen1 mutant metanephros through RNA sequencing. By real-time reverse transcription-PCR, the expression of both Raldh2 and downstream Ret was reduced in embryonic day (E) 11.5 Gen1 mutant ureters and E13.5 kidneys, and expression of RA receptor alpha was decreased in E13.5 Gen1 mutant ureters and kidneys. Further studies showed that all-trans retinoic acid (ATRA) rescued solitary kidney phenotype and improved ureteric branching; ATRA should be administered after ureteric budding to avoid increasing the incidence of ectopic budding in Gen1 mutants. Luciferase intensity of RA response element was lower in CHO-K1 cells transfected with Gen1 siRNA than in those transfected with scrambled RNA, and this inhibitory effect could be reversed by ATRA. These findings indicate that Gen1 mutation can result in renal malformation through RA signaling and Gen1-loss-induced CAKUT can be partly rescued by ATRA.

Topics: Animals; CHO Cells; Cricetulus; Disease Models, Animal; Holliday Junction Resolvases; Kidney; Mice; Mutation; Signal Transduction; Tretinoin; Urinary Tract; Urogenital Abnormalities; Vesico-Ureteral Reflux

Distraction osteogenesis (DO) is used to treat specific disorders associated with growth abnormalities and/or loss of bone stock secondary to trauma or disease. However, a high rate of complications and discomfort hamper its further application in clinical practice. Here, we investigated the effects of all-trans retinoic acid (ATRA) on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs) and bone consolidation in a rat DO model. Different doses of ATRA were used to treat rBMSCs. Cell viability and osteogenic differentiation were assessed using CCK-8 and alkaline phosphatase staining, respectively. The mRNA expression of osteogenic differentiation-genes (including ALP, Runx2, OCN, OPN, OSX, and BMP2) and angiogenic genes (including VEGF, HIF-1, FLK-2, ANG-2, and ANG-4) were determined by quantitative real-time PCR analysis. Further, we locally injected ATRA or PBS into the gap in the rat DO model every 3 days until termination. X-rays, micro-computed tomography (Micro-CT), mechanical testing, and immunohistochemistry stains were used to evaluate the quality of the regenerates. ATRA promoted osteogenic differentiation of rBMSCs. Moreover, ATRA elevated the mRNA expression levels of osteogenic differentiation-genes and angiogenic genes. In the rat model, new bone properties of bone volume/total tissue volume and mechanical strength were significantly higher in the ATRA-treatment group. Micro-CT examination showed more mineralized bone after the ATRA-treatment, and immunohistochemistry demonstrated more new bone formation after ATRA-treatment than that in the PBS group. In conclusion, as a readily available and very cost effective bio-source, ATRA may be a novel therapeutic method to enhance bone consolidation in the clinical setting.

Topics: Animals; Bone and Bones; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Male; Mesenchymal Stem Cells; Osteoblasts; Osteogenesis; Osteogenesis, Distraction; Rats; Rats, Sprague-Dawley; Tretinoin

Direct conversion is considered a promising approach to obtain tissue-specific cells for cell therapies; however, this strategy depends on exogenous gene expression that may cause undesired adverse effects such as tumorigenesis. By optimizing the Schwann cell induction system, which was originally developed for trans-differentiation of bone marrow mesenchymal stem cells into Schwann cells, we established a system to directly convert adult human skin fibroblasts into cells comparable to authentic human Schwann cells without gene introduction. Serial treatments with beta-mercaptoethanol, retinoic acid, and finally a cocktail of basic fibroblast growth factor, forskolin, platelet-derived growth factor-AA, and heregulin-β1 (EGF domain) converted fibroblasts into cells expressing authentic Schwann cell markers at an efficiency of approximately 75%. Genome-wide gene expression analysis suggested the conversion of fibroblasts into the Schwann cell-lineage. Transplantation of induced Schwann cells into severed peripheral nerve of rats facilitated axonal regeneration and robust functional recovery in sciatic function index comparable to those of authentic human Schwann cells. The contributions of induced Schwann cells to myelination of regenerated axons and re-formation of neuromuscular junctions were also demonstrated. Our data clearly demonstrated that cells comparable to functional Schwann cells feasible for the treatment of neural disease can be induced from adult human skin fibroblasts without gene introduction. This direct conversion system will be beneficial for clinical applications to peripheral and central nervous system injuries and demyelinating diseases.

Topics: Animals; Antineoplastic Agents; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Fibroblasts; Green Fluorescent Proteins; Humans; Locomotion; Male; Microscopy, Electron; Myelin P0 Protein; Peripheral Nerve Injuries; Rats; Rats, Wistar; Recovery of Function; RNA, Messenger; Schwann Cells; Serum; Skin; SOXE Transcription Factors; Time Factors; Tretinoin

Tubular injury and interstitial fibrosis are the hallmarks of chronic kidney disease. While recent studies have verified that proximal tubular injury triggers interstitial fibrosis, the impact of fibrosis on tubular injury and regeneration remains poorly understood. We generated a novel mouse model expressing diphtheria toxin receptor on renal fibroblasts to allow for the selective disruption of renal fibroblast function. Administration of diphtheria toxin induced upregulation of the tubular injury marker Ngal and caused tubular proliferation in healthy kidneys, whereas administration of diphtheria toxin attenuated tubular regeneration in fibrotic kidneys. Microarray analysis revealed down-regulation of the retinol biosynthesis pathway in diphtheria toxin-treated kidneys. Healthy proximal tubules expressed retinaldehyde dehydrogenase 2 (RALDH2), a rate-limiting enzyme in retinoic acid biosynthesis. After injury, proximal tubules lost RALDH2 expression, whereas renal fibroblasts acquired strong expression of RALDH2 during the transition to myofibroblasts in several models of kidney injury. The retinoic acid receptor (RAR) RARγ was expressed in proximal tubules both with and without injury, and αB-crystallin, the product of an RAR target gene, was strongly expressed in proximal tubules after injury. Furthermore, BMS493, an inverse agonist of RARs, significantly attenuated tubular proliferation in vitro. In human biopsy tissue from patients with IgA nephropathy, detection of RALDH2 in the interstitium correlated with older age and lower kidney function. These results suggest a role of retinoic acid signaling and cross-talk between fibroblasts and tubular epithelial cells during tubular injury and regeneration, and may suggest a beneficial effect of fibrosis in the early response to injury.

Topics: Aldehyde Dehydrogenase 1 Family; Aldehyde Oxidoreductases; Animals; Benzoates; Biomarkers; Biopsy; Cell Line; Cell Proliferation; Diphtheria Toxin; Disease Models, Animal; Epithelial Cells; Fibrosis; Glomerulonephritis, IGA; Humans; Kidney Tubules, Proximal; Lipocalin-2; Mice; Myofibroblasts; Receptors, Retinoic Acid; Regeneration; Renal Insufficiency, Chronic; Retinal Dehydrogenase; Retinoic Acid Receptor gamma; Stilbenes; Tretinoin; Up-Regulation

Enhanced peripheral complement activation has long been considered as one of the major pathogenic elements of immune thrombocytopenia. A dysfunctional bone marrow microenvironment, especially with regards to mesenchymal stem cells, has been observed in patients with immune thrombocytopenia. However, the potential role of the complement system in the dysfunctional bone marrow microenvironment remains poorly understood. In this study, bone marrow samples from patients with immune thrombocytopenia were divided into two groups based on whether or not complement components were deposited on the surfaces of their mesenchymal stem cells. The mesenchymal cells from the group with complement deposition were less numerous, dysfunctional, had a reduced capacity to proliferate, and showed increased apoptosis as well as abnormal secretion of interleukin-1β and C-X-C motif chemokine ligand 12.

Topics: Animals; Apoptosis; Bone Marrow; Cell Differentiation; Complement Activation; Complement System Proteins; Disease Models, Animal; Gene Expression Profiling; Humans; Interleukin-1beta; Mesenchymal Stem Cells; Mice; Models, Biological; Protective Agents; Purpura, Thrombocytopenic, Idiopathic; Transcriptome; Tretinoin

The Wilms' tumor suppressor gene (Wt1) encodes a zinc finger transcription factor that plays an essential role in the development of kidneys, gonads, spleen, adrenals and heart. Recent findings suggest that WT1 could also be playing physiological roles in adults. Systemic deletion of WT1 in mice provokes a severe deterioration of the exocrine pancreas, with mesothelial disruption, E-cadherin downregulation, disorganization of acinar architecture and accumulation of ascitic transudate. Despite this extensive damage, pancreatic stellate cells do not become activated and lose their canonical markers. We observed that pharmacological induction of pancreatitis in normal mice provokes de novo expression of WT1 in pancreatic stellate cells, concomitant with their activation. When pancreatitis was induced in mice after WT1 ablation, pancreatic stellate cells expressed WT1 and became activated, leading to a partial rescue of the acinar structure and the quiescent pancreatic stellate cell population after recovery from pancreatitis. We propose that WT1 modulates through the RALDH2/retinoic acid axis the restabilization of a part of the pancreatic stellate cell population and, indirectly, the repair of the pancreatic architecture, since quiescent pancreatic stellate cells are required for pancreas stability and repair. Thus, we suggest that WT1 plays novel and essential roles for the homeostasis of the adult pancreas and, through its upregulation in pancreatic stellate cells after a damage, for pancreatic regeneration. Due to the growing importance of the pancreatic stellate cells in physiological and pathophysiological conditions, these novel roles can be of translational relevance.

Topics: Aldehyde Oxidoreductases; Animals; Cell Lineage; Ceruletide; Disease Models, Animal; Epithelium; Gene Expression; Genes, Wilms Tumor; Homeostasis; Humans; Mice; Mice, Knockout; Mice, Transgenic; Pancreas; Pancreatic Stellate Cells; Pancreatitis; Regeneration; Repressor Proteins; Tissue Distribution; Translational Research, Biomedical; Tretinoin; WT1 Proteins

The present study was conducted to assess the effect of all-trans retinoic acid (ATRA) on synovial explants from rats with rheumatoid arthritis (RA) induced by lipopolysaccharides (LPS). In our study, synovial membranes were excised from the knees of healthy adult Wistar female rats under sterile conditions. We first investigated the synoviums incubated in a control medium or in a medium containing 10 μg/mL LPS, each for 24, 48, and 72 h (LPS-experiment). The changes in inflammatory response from the synoviums were observed at different culture times. Then, we assessed the synoviums exposed to different ATRA concentrations for 24 h (ATRA-experiment). The controls (blank, model group, and solvent groups) were set up. The effects of ATRA on synovitis were evaluated by measuring the production of cytokines, and nitric oxide (NO) and the expression of cartilage damage related proteases. In the LPS-experiment, LPS contributed to the release of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and matrix metalloproteinase-9 (MMP-9) in synovial explants. Importantly, LPS did not cause a significant pathological damage. The inflammatory response observed in this model was significant for 24 h, suggesting that LPS-induced synovial explants were successfully established. In the ATRA-experiment, ATRA suppressed the expression of IL-6, TNF-α, NO, a disintegrin and metalloprotease with thrombospondin motifs-4 (ADAMTS-4), MMP-3, and MMP-9. Taken together, ATRA exhibited inhibitory effects on LPS-induced synovial immune inflammatory response stimulated by the regulation of inflammatory mediators and cartilage damage related proteases in synovial explants, demonstrating a potential protective effect on synovitis and joint destruction in the patients with RA.

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Cytokines; Disease Models, Animal; Female; Knee Joint; Lipopolysaccharides; Nitric Oxide; Rats; Rats, Wistar; Synovial Membrane; Synovitis; Tretinoin

Light responses are initiated in photoreceptors, processed by interneurons, and synaptically transmitted to retinal ganglion cells (RGCs), which send information to the brain. Retinitis pigmentosa (RP) is a blinding disease caused by photoreceptor degeneration, depriving downstream neurons of light-sensitive input. Photoreceptor degeneration also triggers hyperactive firing of RGCs, obscuring light responses initiated by surviving photoreceptors. Here we show that retinoic acid (RA), signaling through its receptor (RAR), is the trigger for hyperactivity. A genetically encoded reporter shows elevated RAR signaling in degenerated retinas from murine RP models. Enhancing RAR signaling in healthy retinas mimics the pathophysiology of degenerating retinas. Drug inhibition of RAR reduces hyperactivity in degenerating retinas and unmasks light responses in RGCs. Gene therapy inhibition of RAR increases innate and learned light-elicited behaviors in vision-impaired mice. Identification of RAR as the trigger for hyperactivity presents a degeneration-dependent therapeutic target for enhancing low vision in RP and other blinding disorders.

Topics: Animals; Cell Membrane Permeability; Disease Models, Animal; Electroencephalography; Genetic Therapy; HEK293 Cells; Humans; Mice; Patch-Clamp Techniques; Photosensitivity Disorders; Rats; Receptors, Retinoic Acid; Retinal Degeneration; Retinal Ganglion Cells; Retinitis Pigmentosa; Tretinoin; Vision, Ocular

Contrast-induced acute kidney injury (CI-AKI) has been the third leading cause of hospital-acquired AKI. Retinoic acid (RA), the main derivative of vitamin A, has preventative and therapeutic effects in ischemia-reperfusion-AKI and UUO models, but little is known about its effects on CI-AKI. This study aimed to explore the effects of RA on CI-AKI as well as the underlying mechanisms.. We established a new miniature pig model of CI-AKI by catheterizing the external jugular vein and injecting a single dose of iohexol after dehydration. Bun, Scr, serum and urinary RBP and β-MG levels were measured. Renal histological, TEM examination, LDH assays, TUNEL assays, GFP-LC3 plasmid transfection and western blotting were performed.. The levels of Bun, Scr, serum and urinary RBP and β-MG were increased after CI-AKI and decreased by RA pretreatment. The renal histology showed foamy degeneration and dilated tubules after CI-AKI, and the tissue damage was alleviated significantly by RA pretreatment. RA mitigated renal fibrosis after CI-AKI. In vitro, RA protected proximal TECs against iohexol-induced injury. RA inhibited TECs apoptosis and activated autophagy in vivo and in vitro.. RA alleviates CI-AKI and mitigates renal fibrosis after CI-AKI. Autophagy activation and apoptosis inhibition are involved in the protective effect of RA on CI-AKI. RA may be a new agent for the prevention and therapeutic treatment of CI-AKI in the future.

Topics: Acute Kidney Injury; Animals; Apoptosis; Contrast Media; Disease Models, Animal; Humans; Protective Agents; Swine; Swine, Miniature; Tretinoin

Although targeted therapies have proven effective and even curative in human leukaemia, resistance often ensues. IDH enzymes are mutated in ~20% of human AML, with targeted therapies under clinical evaluation. We here characterize leukaemia evolution from mutant IDH2 (mIDH2)-dependence to independence identifying key targetable vulnerabilities of mIDH2 leukaemia that are retained during evolution and progression from early to late stages. Mechanistically, we find that mIDH2 leukaemia are metastable and vulnerable at two distinct levels. On the one hand, they are characterized by oxidative and genotoxic stress, in spite of increased 1-carbon metabolism and glutathione levels. On the other hand, mIDH2 leukaemia display inhibition of LSD1 and a resulting transcriptional signature of all-trans retinoic acid (ATRA) sensitization, in spite of a state of suppressed ATRA signalling due to increased levels of PIN1. We further identify GSH/ROS and PIN1/LSD1 as critical nodes for leukaemia maintenance and the combination of ATRA and arsenic trioxide (ATO) as a key therapeutic modality to target these vulnerabilities. Strikingly, we demonstrate that the combination of ATRA and ATO proves to be a powerfully synergistic and effective therapy in a number of mouse and human mIDH1/2 leukemic models. Thus, our findings pave the way towards the treatment of a sizable fraction of human AMLs through targeted APL-like combinatorial therapies.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Arsenic Trioxide; Disease Models, Animal; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Leukemia, Promyelocytic, Acute; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Neoplasms, Experimental; Tretinoin; Tumor Cells, Cultured; U937 Cells

Current therapies for gut inflammation have not reached the desired specificity and are attended by unintended immune suppression. This study aimed to provide evidence for supporting a hypothesis that direct in vivo augmentation of the induction of gut-homing regulatory T (Treg) cells is a strategy of expected specificity for the treatment of chronic intestinal inflammation (e.g., inflammatory bowel disease). We showed that dendritic cells (DCs), engineered to de novo produce high concentrations of both 1,25-dihydroxyvitamin D, the active vitamin D metabolite, and retinoic acid, an active vitamin A metabolite, augmented the induction of T cells that express both the regulatory molecule Foxp3 and the gut-homing receptor CCR9 in vitro and in vivo. In vivo, the newly generated Ag-specific Foxp3

Topics: Adoptive Transfer; Animals; Cells, Cultured; Colitis; Dendritic Cells; Disease Models, Animal; Forkhead Transcription Factors; Humans; Immunosuppression Therapy; Inflammatory Bowel Diseases; Intestines; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Receptors, CCR; Receptors, Lymphocyte Homing; T-Lymphocytes, Regulatory; Tretinoin; Vitamin D

To develop a fetal mouse model of non-compaction of ventricular myocardium (NVM) using All-trans retinoic acid (ATRA).. Pregnant mice were divided into blank control group, dimethyl sulfoxide (DMSO) control group and ATRA group. The pregnant mice at 8.5 days after pregnancy were given 70 mg/kg ATRA in DMSO to induce fetal mouse model of NVM in ATRA group. All the hearts were acquired and sliced in short axis from the neonatal mice sacrificed after delivery. Pathological changes were visualized under 40- and 100-fold magnification with Hematoxylin-eosin (HE) staining at different ventricular levels. The criteria for pathological diagnosis of classical NVM were: prominent trabeculations on the endocardial surface and deep intertrabecular recesses communicating with the ventricular cavity and the thickness ratio of non-compacted layer (N) to compact myocardium layer (C) N/C > 1.4. Analysis of variance (ANOVA) and least significant difference (LSD) were used to analyze the differences of three groups, with P < 0.05 considered as significant.. The typical characteristics of NVM histopathological findings of ATRA fetal mouse were confirmed: compared to the hearts of blank control group (n = 20) and DMSO control group (n = 15), all the hearts of ATRA group (n = 17) showed the obviously thinner compacted layer and the much thicker non-compacted layer. The N/C ratio of left ventricles (LVs) in ATRA group was 2.735 ± 1.634, higher than those in DMSO control group 0.178 ± 0.119 and blank control group 0.195 ± 0.118 with significant difference (F = 32.550, P <0. 0001); N/C ratios of right ventricles (RVs) in the ATRA group were (6.068 ± 4.394), higher than those in the DMSO control group 0.459 ± 0.24 and in the blank control group 0.248 ± 0.182 with significant difference (F = 20.069, P <0.0001). LSD of LVs and RVs showed a significant difference between ATRA and blank control group (P < 0.0001), and between ATRA and DMSO control group (P < 0.0001). LSD showed no significant difference in two control groups of LVs (P = 0.963) and of RVs (P = 0.848) .. Excess ATRA could be used to induce NVM of fetal mice heart. This animal model might provide a platform for fundamental research of NVM pathogenesis and potential targeting treatment.

Topics: Animals; Disease Models, Animal; Fetus; Heart; Heart Ventricles; Mice; Myocardium; Tretinoin

The disruption of intestinal mucosal immune tolerance can lead to the development of intestinal immune diseases such as food allergy (FA). Regulatory T cells (Tregs) in the mucosa play a critical role in maintaining peripheral immune tolerance in the intestine, and retinoic acid (RA) is absolutely required for the induction of Tregs. We have previously reported that kakkonto, a traditional Japanese herbal medicine, suppresses FA in a murine FA model due to the induction of Tregs in the colonic mucosa. However, the precise molecular mechanisms underlying the induction of Tregs remain unclear. Puerarin, an isoflavone derivative, is a major constituent of kakkonto. Thus, we investigated the effect of puerarin on the induction of Tregs. BALB/c mice were systemically sensitized and then orally challenged with ovalbumin (OVA) as an FA model. Puerarin treatment suppressed the development of allergic diarrhea in FA mice. The gene expression levels of IL-4 and mast cell protease I (mMCP-1) were significantly upregulated in the proximal colon of FA mice but were reduced by puerarin. The proportions of Foxp3

Topics: Animals; Cells, Cultured; Dendritic Cells; Disease Models, Animal; Food Hypersensitivity; Forkhead Transcription Factors; Immune Tolerance; Intestinal Mucosa; Isoflavones; Mice, Inbred BALB C; Mice, Knockout; Mice, Transgenic; T-Lymphocytes, Regulatory; Tretinoin; Vasodilator Agents

The mortality and morbidity of patients with congenital diaphragmatic hernia (CDH) is primarily caused by treatment-resistant, persistent pulmonary hypertension. Structural vascular changes, exemplified by extensive muscularization, are already present early in gestation, but the origin of these abnormalities is unknown. Understanding the origin of the vascular defects is important to improve treatment modalities. Here, we show that the distribution of pericytes is different and may thereby potentially initiate the vascular pathology in CDH. Transient inhibition of retinoic acid (RA) signaling early during pregnancy, the basis of the CDH mouse model, led to an increase in the number of pericytes, thereby affecting the angiogenic potential of pericytes in the fetuses. Pericytes of CDH lungs showed reduced proliferation and an increased ACTA2 expression, which indicates that these pericytes are more contractile than in control lung pericytes. This resulted in increased pericyte coverage of pulmonary vessels and reduced expansion of the capillary bed, the earliest pathological sign of the structural changes in CDH. Furthermore, the pericytes had reduced and altered collagen IV deposition in CDH, pointing to a loss of basal membrane integrity between pericytes and endothelial cells. Inhibition of RA signaling in vitro resulted in reduced migration of pericytes, reduced angiogenesis, and loss of collagen IV expression. Importantly, we confirmed our findings in lungs of human CDH patient samples. In summary, inhibition of RA signaling affects the lung pericyte population, leading to increased contractility, reduced pulmonary angiogenesis, and aberrant lung development, as observed in CDH.

Topics: Animals; Cell Differentiation; Disease Models, Animal; Endothelial Cells; Hernias, Diaphragmatic, Congenital; Humans; Hypertension, Pulmonary; Lung; Mice; Pericytes; Signal Transduction; Tretinoin

This study aimed to find out the molecular therapeutic effect of lipo-ATRA on tumour suppressor TIG3 and cell proliferative biomarker PPARγ in B (a) P-induced lung cancer model. In RT-PCR study, ATRA- and lipo-ATRA-treated mice samples showed relatively higher TIG3 expression and decreased PPARγ expression (Band density) than cancer control. Among treatments, lipo-ATRA showed vital effect than free ATRA by enhancing TIG3 and decreasing PPARγ. The qPCR results also showed significant (p ≤ 0.05) difference in both TIG3 and PPAR (RQ values of TIG3, lipo-ATRA 23.85 ± 1.29; free ATRA 10.43 ± 1.81 and for PPARγ, lipo-ATRA 4.707 ± 1.21; free ATRA 15.78 ± 2.34). From this, we conclude that liposomal ATRA formulation is most preferable for prolonged delivery of ATRA at targeted site to favour molecular action. It implies that the therapeutic effect of lipo-ATRA in lung cancer was exhibited by ameliorating the TIG3 expression and by suppressing the expression of PPARγ.

Topics: Animals; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Liposomes; Lung Neoplasms; Male; Mice; PPAR gamma; Receptors, Retinoic Acid; Tretinoin; Tumor Suppressor Proteins

Retinoic acid (RA), an active derivative of vitamin A, is critical for the neural system development. During the neural development, the RA/RA receptor (RAR) pathway suppresses BMP signaling-mediated proliferation and differentiation of neural progenitor cells. However, how the stability of RAR is regulated during neural system development and how BMP pathway genes expression in neural tissue from human fetuses affected with neural tube defects (NTDs) remain elusive. Here, we report that FBXO30 acts as an E3 ubiquitin ligase and targets RARγ for ubiquitination and proteasomal degradation. In this way, FBXO30 positively regulates BMP signaling in mammalian cells. Moreover, RA treatment leads to suppression of BMP signaling by reducing the level of FBXO30 in mammalian cells and in mouse embryos with NTDs. In samples from human NTDs with high levels of retinol, downregulation of BMP target genes was observed, along with aberrant FBXO30 levels. Collectively, our results demonstrate that RARγ levels are controlled by FBXO30-mediated ubiquitination and that FBXO30 is a key regulator of BMP signaling. Furthermore, we suggest a novel mechanism by which high-retinol levels affect the level of FBXO30, which antagonizes BMP signaling during early stage development.

Topics: Animals; Bone Morphogenetic Protein 2; Disease Models, Animal; Embryo, Mammalian; F-Box Proteins; Female; Fetus; Gene Expression Regulation, Developmental; HEK293 Cells; Humans; Male; Mass Spectrometry; Mice; Mice, Inbred C57BL; Neural Tube Defects; Protein Binding; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; Signal Transduction; Tretinoin; Ubiquitination

Activation of hepatic stellate cells (HSCs) is the effector factor of hepatic fibrosis and hepatocellular carcinoma (HCC) development. Accumulating evidence suggests that retinoic acids (RAs), derivatives of vitamin A, contribute to prevention of liver fibrosis and carcinogenesis, however, regulatory mechanisms of RAs still remain exclusive. To elucidate RA signaling pathway, we previously performed a genome-wide screening of RA-responsive genes by in silico analysis of RA-response elements, and identified 26 RA-responsive genes. We found that thioredoxin interacting protein (TXNIP), which inhibits antioxidant activity of thioredoxin (TRX), was downregulated by all-trans retinoic acid (ATRA). In the present study, we demonstrate that ATRA ameliorates activation of HSCs through TXNIP suppression. HSC activation was attenuated by TXNIP downregulation, whereas potentiated by TXNIP upregulation, indicating that TXNIP plays a crucial role in activation of HSCs. Notably, we showed that TXNIP-mediated HSC activation was suppressed by antioxidant N-acetylcysteine. In addition, ATRA treatment or downregulation of TXNIP clearly declined oxidative stress levels in activated HSCs. These data suggest that ATRA plays a key role in inhibition of HSC activation via suppressing TXNIP expression, which reduces oxidative stress levels.

Topics: Animals; Antioxidants; Carrier Proteins; Cell Line; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Hepatic Stellate Cells; Humans; Mice, Inbred C57BL; Oxidative Stress; RNA Interference; Signal Transduction; Thioredoxins; Transfection; Tretinoin; Vitamin A Deficiency

The precise molecular basis of retinoid embryopathy is yet unknown. This hypothesis predicts that isotretinoin (13-cis retinoic acid), the prodrug of all-trans retinoic acid (ATRA), exaggerates neural crest cell (NCC) apoptosis via upregulation of the pro-apoptotic transcription factor p53, the guardian of the genome. Increased p53 signalling is associated with Treacher Collins-, CHARGE- and fetal alcohol syndrome, which exhibit dysmorphic craniofacial features resembling retinoid embryopathy. In addition, developmental studies of NCC homeostasis in the zebrafish support the pivotal role of p53. Translational evidence implies that isotretinoin-stimulated overactivation of p53 during embryogenesis represents the molecular basis of isotretinoin's teratogenicity.

Topics: Animals; Apoptosis; CHARGE Syndrome; Disease Models, Animal; Embryonic Development; Fetal Alcohol Spectrum Disorders; Homeostasis; Humans; Isotretinoin; Mandibulofacial Dysostosis; Neural Crest; Signal Transduction; Teratogens; Translational Research, Biomedical; Tretinoin; Tumor Suppressor Protein p53; Up-Regulation; Zebrafish

Stimulation of retinoic acid (RA) mediated signalling pathways following neural injury leads to regeneration in the adult nervous system and numerous studies have shown that the specific activation of the retinoic acid receptor β (RARβ) is required for this process. Here we identify a novel mechanism by which neuronal RARβ activation results in the endogenous synthesis of RA which is released in association with exosomes and acts as a positive cue to axonal/neurite outgrowth. Using an established rodent model of RARβ induced axonal regeneration, we show that neuronal RARβ activation upregulates the enzymes involved in RA synthesis in a cell specific manner; alcohol dehydrogenase7 (ADH7) in neurons and aldehyde dehydrogenase 2 (Raldh2) in NG2 expressing cells (NG2+ cells). These release RA in association with exosomes providing a permissive substrate to neurite outgrowth. Conversely, deletion of Raldh2 in the NG2+ cells in our in vivo regeneration model is sufficient to compromise axonal outgrowth. This hitherto unidentified RA paracrine signalling is required for axonal/neurite outgrowth and is initiated by the activation of neuronal RARβ signalling.

Topics: Aldehyde Oxidoreductases; Animals; Antigens; Biological Transport; Cells, Cultured; Cervical Cord; Coculture Techniques; Disease Models, Animal; Exosomes; Male; Mice; Nerve Regeneration; Neuroglia; Neuronal Outgrowth; Neurons; Proteoglycans; Rats, Sprague-Dawley; Receptors, Retinoic Acid; Retinal Dehydrogenase; Spinal Nerve Roots; Tretinoin

Cholestatic liver injury is mediated by bile acid-induced inflammatory responses. We hypothesized that superior therapeutic effects might be achieved by combining treatments that reduce the bile acid pool size with one that blocks inflammation.. All-trans retinoic acid alone reduced bile acid pool size and liver necrosis in BDL rats. However, the combination with CVC further reduced liver to body weight ratio, bile acid pool size, plasma liver enzyme, bilirubin, liver necrosis and fibrosis when compared to the atRA treatment. The assessment of hepatic hydroxyproline content further confirmed the reduced liver injury concurrent with reduction of pro-inflammatory cytokines emphasizing the synergistic effects of these two agents. Profiling of hepatic inflammatory cells revealed that combination therapy reduced neutrophils and T cells but not macrophages. The superior therapeutic effects of combination treatment were also confirmed in Mdr2. Multitargeted therapy is an important paradigm for treating cholestatic liver injury. The combination of CVC with atRA or other FXR activators may warrant a clinical trial in patients with cholestatic liver disease.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Bile Acids and Salts; Cholestasis; Disease Models, Animal; Drug Therapy, Combination; Imidazoles; Ligation; Liver; Liver Diseases; Male; Mice; Mice, Knockout; Rats; Rats, Sprague-Dawley; Receptors, Cytokine; Sulfoxides; Tretinoin

CHD7, an ATP-dependent chromatin remodeler, is disrupted in CHARGE syndrome, an autosomal dominant disorder characterized by variably penetrant abnormalities in craniofacial, cardiac, and nervous system tissues. The inner ear is uniquely sensitive to CHD7 levels and is the most commonly affected organ in individuals with CHARGE. Interestingly, upregulation or downregulation of retinoic acid (RA) signaling during embryogenesis also leads to developmental defects similar to those in CHARGE syndrome, suggesting that CHD7 and RA may have common target genes or signaling pathways. Here, we tested three separate potential mechanisms for CHD7 and RA interaction: (a) direct binding of CHD7 with RA receptors, (b) regulation of CHD7 levels by RA, and (c) CHD7 binding and regulation of RA-related genes. We show that CHD7 directly regulates expression of Aldh1a3, the gene encoding the RA synthetic enzyme ALDH1A3 and that loss of Aldh1a3 partially rescues Chd7 mutant mouse inner ear defects. Together, these studies indicate that ALDH1A3 acts with CHD7 in a common genetic pathway to regulate inner ear development, providing insights into how CHD7 and RA regulate gene expression and morphogenesis in the developing embryo.

Topics: Aldehyde Oxidoreductases; Animals; Cell Line, Tumor; CHARGE Syndrome; Disease Models, Animal; DNA Helicases; DNA-Binding Proteins; Ear, Inner; Embryo, Mammalian; Female; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Knockdown Techniques; HEK293 Cells; Humans; Male; Mice; Mice, Transgenic; Organogenesis; Retinal Dehydrogenase; RNA, Small Interfering; Tretinoin

In this research, we explored the molecular mechanism of proteinuria in glomerulosclerosis rats and the protective effects of ATRA.. This research set up three groups: SHO group, GS group, and ATRA group (15 mg/(kg d), Sigma, St. Louis, MO). The serum creatinine (Scr), urea nitrogen (BUN), and 24-h proteinuria were detected 12 weeks after administration of ATRA. The pathological and ultrastructure changes were observed under light microscope and transmission electron microscope. The protein expression of TGF-β. In the rat model of GS, the expressions of TRPC6 were significantly elevated compared with the normal rat group; however, the use of ATRA down-regulated the expression of TRPC6 in the glomeruli and attenuated glomerulosclerosis and proteinuria. Scr and BUN were also improved by the treatment of ATRA.. Our results demonstrated that ATRA could ameliorate glomerulosclerosis and proteinuria in GS, which may be related to suppressed expression of TRPC6.

Topics: Animals; Collagen Type IV; Disease Models, Animal; Down-Regulation; Doxorubicin; Glomerulosclerosis, Focal Segmental; Kidney Glomerulus; Male; Microscopy, Electron, Transmission; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta1; Tretinoin; TRPC Cation Channels

Exaggerated inflammation that characterizes necrotizing enterocolitis (NEC) is caused by the invasion of pathogens through an immature intestinal barrier. Vitamin A (VA) and retinoic acid (RA) play important roles in the growth of epithelial tissue and in modulating immune function.. To investigate the roles of VA and RA in the development of NEC.. Levels of serum retinol in patients and in a NEC mouse model were detected with high-performance liquid chromatography. Bacterial communities of NEC mice treated with VA or PBS were detected by high-throughput sequencing. In vitro and in vivo, levels of inflammatory factors were measured by ELISA and RT-PCR, and expression levels of claudin-1, occludin, and ZO-1 were detected by Western blotting. Transepithelial electrical resistance (TEER) was measured in Caco-2 cell monolayers.. The level of VA in the NEC patients was lower than in the control patients. In the NEC mice that were treated with VA versus PBS, the proportion of Escherichia-Shigella was lower, while the abundance of Bacteroides was markedly higher. Both in vivo and in vitro, the levels of inflammatory factors were significantly reduced, while the expression levels of claudin-1, occludin, and ZO-1 were increased, after the VA and RA treatments. Meanwhile, TEER was increased and lipopolysaccharide-induced damage was reduced in Caco-2 cell monolayers after RA treatment.. These results suggest that VA may regulate intestinal flora, alleviate inflammatory reactions, and enhance the intestinal epithelial barrier in NEC. Thus, VA may be an effective drug for providing protection against NEC in newborns.

Topics: Animals; Caco-2 Cells; Cell Line, Tumor; Claudin-1; Disease Models, Animal; Enterocolitis, Necrotizing; Gastrointestinal Microbiome; Humans; Infant, Newborn; Intestinal Mucosa; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Occludin; Tight Junctions; Tretinoin; Zonula Occludens-1 Protein

All-trans retinoic acid (ATRA) or mesenchymal stem cells (MSCs) have been shown to promote lung tissue regeneration in animal models of emphysema. However, the reparative effects of the combination of the two and the role of p70S6 kinase-1 (p70S6k1) activation in the repair process have not been defined. Twenty-one days after intratracheal instillation of porcine pancreatic elastase (PPE), MSC and/or 10 days of ATRA treatment was initiated. Thirty-two days later, static lung compliance (Cst), mean linear intercepts (MLIs), and alveolar surface area (S) were measured. After PPE, mice demonstrated increased values of Cst and MLI, and decreased S values. Both ATRA and MSC transfer were individually effective in improving these outcomes while the combination of ATRA and MSCs was even more effective. The combination of p70S6k1

Topics: Animals; Bone Marrow Cells; Disease Models, Animal; Female; Lung; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Pancreatic Elastase; Phosphorylation; Pulmonary Emphysema; Regeneration; Ribosomal Protein S6 Kinases, 70-kDa; Tissue Engineering; Tretinoin

Endothelial progenitor cells (EPCs) play a critical role in neovascularization, which enhances proliferation under all-trans retinoic acid (ATRA) treatment. However, the effects of ATRA on the skin flap survival in diabetic flap ischemia remains unknown.. Ischemic random skin flaps were made in 40 diabetic Sprague-Dawley rats with 20 normal rats used as control in this study. At 7 days postoperatively, the surviving area of each skin flap was measured. Immunofluorescence staining was used to analyze capillary density and EPCs recruited to the flaps. The expression of ANG2 and VEGF was determined by Western blotting. Circulating EPC number was determined by flow cytometry. In vitro tube formation experiment was used to analyze the function of EPCs.. The flap survival rate and capillary density of ATRA-treated flap were significantly increased. Fluorescence-activated cell sorting (FACS) analysis demonstrated a marked increase in systemic CD34+/Flk-1+ EPCs in ATRA-treated rat. The expression of ANG2 and VEGF was increased in diabetic flap tissues under ATRA administration. Furthermore, ATRA administration restored the impaired function of diabetic EPCs in tube formation.. ATRA could notably exert preventive effects against skin flap necrosis and promote neovascularization in diabetic rats, which may partially through elevating the expression of ANG2 and VEGF, and augmenting EPC mobilization.

Topics: Animals; Diabetes Mellitus, Experimental; Disease Models, Animal; Ischemia; Male; Mice; Neovascularization, Physiologic; Postoperative Complications; Rats; Rats, Sprague-Dawley; Surgical Flaps; Tretinoin

Spina bifida aperta is a congenital malformation characterized by the failure of neural tube closure resulting in an unprotected fetal spinal cord. The spinal cord then undergoes progressive damage, likely due to chemical and mechanical factors related to exposure to the intrauterine environment. Astrogliosis in exposed spinal cords has been described in animal models of spina bifida during embryonic life but its relationship with neuroinflammatory processes are completely unknown. Using a retinoic acid-induced rat model of spina bifida we demonstrated that, when exposed to amniotic fluid, fetal spinal cords showed progressive astrogliosis with neuronal loss at mid-gestation (E15) compared to unexposed spinal cords. The number of microglial cells with a reactive phenotype and activation marker expression increased during gestation and exhibited progressive disruption in the inhibitory immune ligand-receptor system. Specifically we demonstrate down-regulation of CD200 expression and up-regulation of CD200R. Exposed spinal cords demonstrated neuroinflammation with increased tissue water content and cytokine production by the end of gestation (E20), which correlated with active Caspase3 expression in the exposed layers. Our findings provide new evidence that microglia activation, including the disruption of the endogenous inhibitory system (CD200-CD200R), may participate in the pathogenesis of spina bifida through late gestation.

Topics: Amniotic Fluid; Animals; Antigens, CD; Caspase 3; Disease Models, Animal; Down-Regulation; Embryo, Mammalian; Female; Humans; Microglia; Pregnancy; Rats; Rats, Sprague-Dawley; Receptors, Immunologic; Spina Bifida Cystica; Spinal Cord; Tretinoin; Up-Regulation

Alcohol abuse affects several neurological pathways and causes significant alterations in the brain. Abstention from alcohol causes only a marginal decrease in oxidative stress and neuro inflammation. Our previous studies had shown that an active metabolite of vitamin A, all trans retinoic acid (ATRA), ameliorates alcohol induced toxicity. Hence in the present study we investigated whether ATRA regressed alcohol induced neuroinflammation. We focused on the role of silent mating type information regulation 2 homolog 1(SIRT1) and nuclear factor kappa-B (NFκB). Animals were administered with ethanol at a daily dose of (4 g/kg body weight) for 90 days. On the 91st day ethanol administration was stopped and animals were divided into ethanol abstention (A) and ATRA supplementation group (ATRA + A) (100 µg/kg body weight) and maintained for 30 days. Ethanol exposure increased markers of oxidative stress, inflammation and the activities of alcohol and acetaldehyde dehydrogenases and reduced the expression of SIRT1 in the whole brain.The ethanol induced altered expressions of NFκB and SIRT1 were modulated by supplementation of ATRA. Abstention also reduced toxicity, but to a lower extent in comparison with supplementation of ATRA. Our results seemed to suggest that ATRA regressed the mediators of ethanol induced neuroinflammation by reducing oxidative stress and by regulating the expression of NFκB and SIRT1. The ameliorative potential of ATRA was much higher than abstention.

Topics: Animals; Brain; Disease Models, Animal; Inflammation; NF-kappa B; Oxidative Stress; Rats, Sprague-Dawley; Sirtuin 1; Tretinoin

Fetal alcohol spectrum disorder caused by prenatal alcohol exposure includes ocular abnormalities (microphthalmia, photoreceptor dysfunction, cataracts). Zebrafish embryos exposed to ethanol from gastrulation through somitogenesis show severe ocular defects, including microphthalmia and photoreceptor differentiation defects. Ethanol-treated zebrafish had an enlarged ciliary marginal zone (CMZ) relative to the retina size and reduced Müller glial cells (MGCs). Ethanol exposure produced immature photoreceptors with increased proliferation, indicating cell cycle exit failure. Signaling mechanisms in the CMZ were affected by embryonic ethanol exposure, including Wnt signaling in the CMZ, Notch signaling and neurod gene expression. Retinoic acid or folic acid co-supplementation with ethanol rescued Wnt signaling and retinal differentiation. Activating Wnt signaling using GSK3 inhibitor (LSN 2105786; Eli Lilly and Co.) restored retinal cell differentiation pathways. Ethanol exposed embryos were treated with Wnt agonist, which rescued Wnt-active cells in the CMZ, Notch-active cells in the retina, proliferation, and photoreceptor terminal differentiation. Our results illustrate the critical role of Wnt signaling in ethanol-induced retinal defects.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Embryo, Nonmammalian; Ethanol; Female; Fetal Alcohol Spectrum Disorders; Folic Acid; Nerve Tissue Proteins; Photoreceptor Cells, Vertebrate; Pregnancy; Receptors, Notch; Retina; Retinal Diseases; Tretinoin; Wnt Signaling Pathway; Zebrafish

Airway smooth muscle (ASM) is a dynamic and complex tissue involved in regulation of bronchomotor tone, but the molecular events essential for the maintenance of ASM homeostasis are not well understood. Observational and genome-wide association studies in humans have linked airway function to the nutritional status of vitamin A and its bioactive metabolite retinoic acid (RA). Here, we provide evidence that ongoing RA signaling is critical for the regulation of adult ASM phenotype. By using dietary, pharmacologic, and genetic models in mice and humans, we show that (a) RA signaling is active in adult ASM in the normal lung, (b) RA-deficient ASM cells are hypertrophic, hypercontractile, profibrotic, but not hyperproliferative, (c) TGF-β signaling, known to cause ASM hypertrophy and airway fibrosis in human obstructive lung diseases, is hyperactivated in RA-deficient ASM, (d) pharmacologic and genetic inhibition of the TGF-β activity in ASM prevents the development of the aberrant phenotype induced by RA deficiency, and (e) the consequences of transient RA deficiency in ASM are long-lasting. These results indicate that RA signaling actively maintains adult ASM homeostasis, and disruption of RA signaling leads to aberrant ASM phenotypes similar to those seen in human chronic airway diseases such as asthma.

Topics: Adult; Animals; Benzoates; Cells, Cultured; Disease Models, Animal; Female; Fibrosis; Humans; Hypertrophy; Lung; Lung Diseases, Obstructive; Male; Mice; Mice, Transgenic; Muscle, Smooth; Myocytes, Smooth Muscle; Primary Cell Culture; Receptors, Retinoic Acid; Signal Transduction; Stilbenes; Tretinoin

Epithelial-mesenchymal transformation of the medial edge epithelium is the most crucial process in embryonic palatal fusion. This study aimed to explore the relationship and potential mechanism between enhancer DNA methylation and mRNA expression of histone deacetylase 4 (HDAC4) during palatal fusion induced by maternal exposure to all-trans retinoic acid (ATRA). Pregnant mice were administered ATRA (70 mg/kg) by gavage at embryonic gestation day 10.5 (E10.5) to establish a cleft palate (CP) model in C57BL/6J mice. Control groups were given an equivalent volume of corn oil. Pregnant mice were dissected at E14.5 (n = 6) to obtain embryonic palates. HDAC4 enhancer DNA methylation data were obtained from a previous MethylRAD-seq. Methylation-specific polymerase chain reaction (MSP) and real-time quantitative PCR were used to quantify enhancer methylation and the mRNA expression level of HDAC4. Enhancer DNA methylation at a non-CpG site within the HDAC4 gene was hyper-methylated at E14.5 (P: 0.011, log

Topics: Animals; Cleft Palate; Disease Models, Animal; DNA Methylation; Enhancer Elements, Genetic; Epigenesis, Genetic; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Developmental; Histone Deacetylases; Maternal Exposure; Mice; Mice, Inbred C57BL; Palate; Pregnancy; RNA, Messenger; Tretinoin

Insulin resistance (IR) is closely associated with the progression of hepatocellular carcinoma (HCC). Acyclic retinoid (ACR) targets retinoid X receptor α and reportedly prevents HCC recurrence in clinical practice. Angiotensin-II receptor blocker (ARB) can also inhibit experimental hepatocarcinogenesis and HCC development. These are reported to suppress IR-based hepatocarcinogenesis; however, limited data are available regarding the combined effects of both these agents. This study aimed to investigate the combined chemopreventive effect of ACR and ARB on liver tumorigenesis on rats with congenital diabetes.. Male diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) and non-diabetic Long-Evans Tokushima Otsuka (LETO) rats underwent 70% partial hepatectomy following a single intraperitoneal injection of diethylnitrosamine to induce hepatocarcinogenesis and the administration of ACR (peretinoin, 40 mg/kg/day), ARB (losartan, 30 mg/kg/day), and a combination of ACR and ARB. Six weeks thereafter, we assessed the size and number of the pre-neoplastic lesions (PNL) as well as the altered angiogenesis, oxidative stress, and chronic inflammation in the liver. Moreover, we assessed the effects exerted by ACR and ARB on in vitro cell growth in human HCC cell lines and human umbilical vascular endothelial cells (HUVECs).. OLETF rats showed increase in the size and number of PNLs compared to LETO rats. ACR suppressed the augmentation in size and number of PNLs in the OLETF rats with suppression of cell growth, intrahepatic angiogenesis, lipid peroxidation, oxidative DNA damage, and proinflammatory cytokine production. Combining ACR with ARB enhanced the tumor-suppressive effect and ameliorated intrahepatic angiogenesis, lipid peroxidation, and proinflammatory status; however, cell growth and oxidative DNA damage remained unchanged. IR-mimetic condition accelerated in vitro proliferative activity in human HCC cells, while ACR inhibited this proliferation with G0/G1 arrest and apoptosis. Furthermore, ACR and ARB significantly attenuated the HUVECs proliferation and tubular formation under the IR-mimetic condition, and a combination of both agents demonstrated greater inhibitory effects on HUVEC growth than each single treatment.. ACR and ARB exert a combined inhibitory effect against IR-based hepatocarcinogenesis by the inhibition of cell growth, intrahepatic angiogenesis, and oxidative stress. Thus, this combination therapy appears to hold potential as a chemopreventive treatment therapy against HCC.

Topics: Angiotensin Receptor Antagonists; Animals; Biomarkers; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Diethylnitrosamine; Disease Models, Animal; DNA Damage; Drug Synergism; Humans; Lipid Peroxidation; Liver Neoplasms; Liver Neoplasms, Experimental; Male; Oxidative Stress; Protective Agents; Rats; Rats, Inbred OLETF; Tretinoin

The resistance mechanisms that limit the efficacy of retinoid therapy in cancer are poorly understood. Sphingosine kinase 2 (SphK2) is a highly conserved enzyme that is mainly located in the nucleus and endoplasmic reticulum. Unlike well-studied sphingosine kinase 1 (SphK1) located in the cytosol, little has yet understood the functions of SphK2. Here we show that SphK2 overexpression contributes to the resistance of all-trans retinoic acid (ATRA) therapy in colon cancer through rapid degradation of cytoplasmic retinoid X receptor α (RXRα) by lysine 48 (K48)- and lysine 63 (K63)-based polyubiquitination. Human colonic adenocarcinoma HCT-116 cells transfected with SphK2 (HCT-116Sphk2 cells) demonstrate resistance to ATRA therapy as determined by in vitro and in vivo assays. Sphk2 overexpression increases the ATRA-induced nuclear RXRα export to cytoplasm and then rapidly degrades RXRα through the polyubiquitination pathway. We further show that Sphk2 activates the ubiquitin-proteasome system through the signal mechanisms of (1) K48-linked proteosomal degradation and (2) K63-linked ubiquitin-dependent autophagic degradation. These results provide new insights into the biological functions of Sphk2 and the molecular mechanisms that underlie the Sphk2-mediated resistance to retinoid therapy.

Topics: Animals; Autophagy; Colonic Neoplasms; Disease Models, Animal; Drug Resistance, Neoplasm; Gene Expression; HCT116 Cells; Humans; Ligands; Mice; Phosphotransferases (Alcohol Group Acceptor); Protein Binding; Protein Transport; Proteolysis; Retinoid X Receptor alpha; Tretinoin; Tumor Burden; Ubiquitination; Ubiquitins; Xenograft Model Antitumor Assays

Desalted duck egg white peptides (DPs) have been proven to promote calcium uptake in Caco-2 cells and rats treated with a calcium-deficient diet. The retinoic acid-induced bone loss model was used to evaluate the effect of DPs on calcium absorption and bone formation. Three-month-old Wistar female rats were treated with 0.9% saline, DPs (800 mg/kg), or alendronate (5 mg/kg) for three weeks immediately after retinoic acid treatment (80 mg/kg) once daily for two weeks. The model group was significantly higher in serum bone alkaline phosphatase than the other three groups (

Topics: Alendronate; Alkaline Phosphatase; Animals; Bone and Bones; Bone Density; Bone Diseases, Metabolic; Caco-2 Cells; Calcium; Calcium Channels; Disease Models, Animal; Ducks; Egg White; Female; Humans; Osteocalcin; Osteoclasts; Osteogenesis; Peptides; Rats; Rats, Wistar; Tretinoin; TRPV Cation Channels

Bacterial outer membrane vesicles have been extensively investigated and considered as a next generation vaccine. Recently, we have demonstrated that the cholera pentavalent outer membrane vesicles (CPMVs) immunogen induced adaptive immunity and had a strong protective efficacy against the circulating V. cholerae strains in a mouse model. In this present study, we are mainly focusing on reducing outer membrane vesicle (OMV) -mediated toxicity without altering its antigenic property. Therefore, we have selected All-trans Retinoic Acid (ATRA), active metabolites of vitamin A, which have both anti-inflammatory and mucosal adjuvant properties. Pre-treatment of ATRA significantly reduced CPMVs induced TLR2 mediated pro-inflammatory responses in vitro and in vivo. Furthermore, we also found ATRA pre-treatment significantly induced mucosal immune response and protective efficacy after two doses of oral immunization with CPMVs (75µg). This study can help to reduce OMV based vaccine toxicity and induce better protective immunity where children and men suffered from malnutrition mainly in developing countries.

Topics: Administration, Oral; Animals; Animals, Newborn; Antibodies, Bacterial; Bacterial Outer Membrane Proteins; Cholera; Cholera Vaccines; Cytokines; Disease Models, Animal; Female; Immunity, Mucosal; Immunogenicity, Vaccine; Immunoglobulin G; Inflammation; Mice; Mice, Inbred BALB C; Toll-Like Receptor 2; Tretinoin; Vibrio cholerae

The loss of cone photoreceptors that mediate daylight vision represents a leading cause of blindness, for which cell replacement by transplantation offers a promising treatment strategy. Here, we characterize cone differentiation in retinas derived from mouse embryonic stem cells (mESCs). Similar to in vivo development, a temporal pattern of progenitor marker expression is followed by the differentiation of early thyroid hormone receptor β2-positive precursors and, subsequently, photoreceptors exhibiting cone-specific phototransduction-related proteins. We establish that stage-specific inhibition of the Notch pathway increases cone cell differentiation, while retinoic acid signaling regulates cone maturation, comparable with their actions in vivo. MESC-derived cones can be isolated in large numbers and transplanted into adult mouse eyes, showing capacity to survive and mature in the subretinal space of Aipl1

Topics: Adaptor Proteins, Signal Transducing; Animals; Basic-Leucine Zipper Transcription Factors; Cell Differentiation; Disease Models, Animal; Eye Proteins; Hepatocyte Nuclear Factor 6; Leukemia Inhibitory Factor; Mice; Mice, Knockout; Mouse Embryonic Stem Cells; Oligodendrocyte Transcription Factor 2; Opsins; Orphan Nuclear Receptors; Otx Transcription Factors; Receptors, Notch; Retinal Cone Photoreceptor Cells; Retinal Degeneration; RNA Interference; RNA, Small Interfering; Signal Transduction; Tretinoin

Alkali burns are the most common, severe chemical ocular injuries, their functional prognosis depending on corneal wound healing efficiency. The purpose of our study was to compare the benefits of amniotic membrane (AM) grafts and homogenates for wound healing in the presence or absence of previous all-trans retinoic acid (atRA) treatment.. Fifty male CD1 mice with reproducible corneal chemical burn were divided into five groups, as follows: group 1 was treated with saline solution; groups 2 and 3 received untreated AM grafts or grafts treated with atRA, respectively; and groups 4 and 5 received untreated AM homogenates or homogenates treated with atRA, respectively. After 7 days of treatment, ulcer area and depth were measured, and vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP-9) were quantified.. AM induction by atRA was confirmed via quantification of retinoic acid receptor β (RARβ), a well-established retinoic acid-induced gene. Significant improvements of corneal wound healing in terms of ulcer area and depth were obtained with both strategies. No major differences were found between the efficiency of AM homogenates and grafts. This positive action was increased when AM was pretreated with atRA. Furthermore, AM induced a decrease in VEGF and MMP-9 levels during the wound healing process. The atRA treatment led to an even greater decrease in the expression of both proteins.. Amnion homogenate is as effective as AM grafts in promoting corneal wound healing in a mouse model. A higher positive effect was obtained with atRA treatment.

Topics: Alkalies; Amnion; Animals; Burns, Chemical; Corneal Ulcer; Disease Models, Animal; Eye Burns; Fluorescent Antibody Technique, Indirect; Humans; Keratolytic Agents; Male; Matrix Metalloproteinase 9; Mice; Tissue Engineering; Transplants; Tretinoin; Vascular Endothelial Growth Factor A; Wound Healing

Topics: Animals; Cell Communication; Disease Models, Animal; Host-Parasite Interactions; Humans; Langerhans Cells; Leishmania major; Leishmaniasis, Cutaneous; Lymph Nodes; Mice; Mice, Knockout; Receptors, CCR7; Skin; T-Lymphocytes, Regulatory; Tretinoin

The current study was designed to elucidate the mechanism of retinol binding protein 4 (RBP4) in cleft palate induced by all‑trans retinoic acid (atRA). To establish a cleft palate model in C57BL/6J mice, pregnant mice were administered atRA (100 mg/kg) by gavage at the tenth embryonic stage (E10.0). Control groups were given the equivalent volume of corn oil. Pregnant mice were dissected at E12.5, E13.5 and E14.5 to obtain the embryonic palates. The expression levels of RBP4 in the embryonic palatal mesenchyme (EPM) were determined by immunohistochemistry, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Human embryonic palatal mesenchymal cells were exposed to atRA to detect the variation in RBP4 induced by atRA in vitro. Small interfering RNA was used to suppress the expression of RBP4, and a plasmid overexpressing RBP4 was used to examine upregulated expression. The cell counting kit‑8 assay was used to evaluate the effect of RBP4 on cell proliferation. The expression levels of p27 and cyclin D1 were determined by RT‑qPCR and western blotting, while the expression levels of extracellular signal‑related kinase (ERK) 1/2 and protein kinase B (AKT) were assessed by western blotting. At E14.5, RBP4 was strongly expressed in the EPM, while it was downregulated following atRA treatment, which induced cleft palate in vivo. In vitro experiments indicated that atRA suppressed the expression of RBP4 and altered the expression of p27 and cyclin D1 to cause growth inhibition. Knockdown of RBP4 resulted in decreased expression of cyclin D1 and increased p27, and suppressed proliferation. Overexpression of RBP4 reversed the inhibitory effect of atRA and promoted proliferation via the ERK1/2 and AKT signaling pathways. These results suggested that RBP4 was involved in cleft palate induced by atRA and it can be suppressed by atRA to cause growth inhibition in the embryonic palate.

Topics: Animals; Cell Line; Cell Proliferation; Cleft Palate; Corn Oil; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Disease Models, Animal; Embryo, Mammalian; Excipients; Female; Gene Expression Regulation, Developmental; Humans; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Pregnancy; Proto-Oncogene Proteins c-akt; Retinol-Binding Proteins, Plasma; RNA, Small Interfering; Signal Transduction; Tretinoin

The farnesoid X receptor (FXR) and C/EBP homologous protein (CHOP) have critical functions in hepatic lipid metabolism. Here, we aimed to explore a potential relationship between FXR and CHOP. We fed wild-type (WT) and FXR KO mice a MCD diet (model of steatohepatitis) and found that Chop mRNA expression is upregulated in WT but not FXR KO mice. The absence of FXR aggravates hepatic inflammation after MCD feeding. In HepG2 cells, we found that Chop expression is regulated in a FXR/Retinoid X receptor (RXR)-dependent manner. We identified a FXR/RXR-binding site in the human CHOP promoter, demonstrating a highly conserved regulatory pathway. Our study shows that FXR/RXR regulates Chop expression in a mouse model of steatohepatitis, providing novel insights into pathogenesis of this disorder.

Topics: Animals; Binding Sites; Chenodeoxycholic Acid; Diet, High-Fat; Disease Models, Animal; Gene Expression Regulation; Glucose; Hep G2 Cells; Humans; Lipid Metabolism; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Non-alcoholic Fatty Liver Disease; Promoter Regions, Genetic; Protein Binding; Receptors, Cytoplasmic and Nuclear; Retinoid X Receptors; RNA, Messenger; Signal Transduction; Transcription Factor CHOP; Tretinoin

To assess the total volume change in a retinoic acid-induced, hypoplastic model of a chick thymus using Image-J.. This experimental study was carried out at the anatomy department of College of Physicians and Surgeons, Islamabad, Pakistan, from February 2009 to February 2010, and comprised fertilised chicken eggs. The eggs were divided into experimental group A and control group C. Group A was injected with 0.3µg of retinoic acid via yolk sac to induce a defective model of a thymus with hypoplasia. The chicks were sacrificed on embryonic day 15 and at hatching. The thymus of each animal was processed, serially sectioned and stained. The total area of each section of thymus was calculated using Image-J. This total area was summed and multiplied with the thickness of each section to obtain volume.. Of the 120 eggs, there were 60(50%) in each group. Image analysis revealed a highly significant decrease in the volume of the chick thymus in the experimental group A than its matched control at the time of hatching (p=0.001). Moreover, volumetric depletion progressed with time, being substantially pronounced at hatching compared to the embryonic stage.. The volume changes were significant and were effectively quantified using Image-J.

Topics: Animals; Chick Embryo; Disease Models, Animal; Image Processing, Computer-Assisted; Organ Size; Software; Teratogens; Thymus Gland; Tretinoin

Group 2 innate lymphoid cells (ILC2s) are involved in human diseases, such as allergy, atopic dermatitis and nasal polyposis, but their function in human cancer remains unclear. Here we show that, in acute promyelocytic leukaemia (APL), ILC2s are increased and hyper-activated through the interaction of CRTH2 and NKp30 with elevated tumour-derived PGD2 and B7H6, respectively. ILC2s, in turn, activate monocytic myeloid-derived suppressor cells (M-MDSCs) via IL-13 secretion. Upon treating APL with all-trans retinoic acid and achieving complete remission, the levels of PGD2, NKp30, ILC2s, IL-13 and M-MDSCs are restored. Similarly, disruption of this tumour immunosuppressive axis by specifically blocking PGD2, IL-13 and NKp30 partially restores ILC2 and M-MDSC levels and results in increased survival. Thus, using APL as a model, we uncover a tolerogenic pathway that may represent a relevant immunosuppressive, therapeutic targetable, mechanism operating in various human tumour types, as supported by our observations in prostate cancer.Group 2 innate lymphoid cells (ILC2s) modulate inflammatory and allergic responses, but their function in cancer immunity is still unclear. Here the authors show that, in acute promyelocytic leukaemia, tumour-activated ILC2s secrete IL-13 to induce myeloid-derived suppressor cells and support tumour growth.

Topics: A549 Cells; Animals; Antineoplastic Agents; B7 Antigens; Cell Line, Tumor; Disease Models, Animal; Hep G2 Cells; HL-60 Cells; Humans; Immunity, Innate; Interleukin-13; Leukemia, Promyelocytic, Acute; Lymphocytes; Mice, Inbred C57BL; Myeloid-Derived Suppressor Cells; Natural Cytotoxicity Triggering Receptor 3; Prostaglandin D2; Protein Binding; Tretinoin

Antigen-specific regulatory T cells (Tregs) possess the potential to reduce excess immune responses in autoimmune diseases, allergy, rejection after organ transplantation and graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation. Although in vitro-expanded antigen-specific induced Tregs (iTregs) have been considered to be a promising therapeutic agent against such excessive immune reactions, the instability of iTregs after transfer is a fundamental problem in their clinical application. In this study, we searched for the optimal way to generate stable iTregs for the prevention of the murine GVHD model, in which conventional iTregs are reported to be inefficient. Allo-antigen-specific iTregs were generated by co-culturing naive T cells with allogenic dendritic cells in the presence of TGF-β and retinoic acid. By examining various agents and genes, we found that vitamin C stabilized Foxp3 expression most effectively in adoptively transferred iTregs under a GVHD environment. Vitamin C treatment caused active DNA demethylation specifically on the conserved non-coding sequence 2 (CNS2) enhancer of the Foxp3 gene locus in allo-antigen-specific iTregs and reduced iTreg conversion into pathogenic exFoxp3 cells. Vitamin C-treated iTregs suppressed GVHD symptoms more efficiently than untreated iTregs. Vitamin C also facilitated induction of a FOXP3high iTreg population from human naive T cells, which was very stable even in the presence of IL-6 in vitro. The treatment of vitamin C for iTreg promises innovative clinical application for adoptive Treg immunotherapy.

Topics: Animals; Ascorbic Acid; Disease Models, Animal; Graft vs Host Disease; Humans; Immunotherapy, Adoptive; Isoantigens; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; T-Lymphocytes, Regulatory; Tretinoin

To determine the growth inhibition capability of all-trans retinoic acid (ATRA) with cytokine-induced killer cells (CIKs), we evaluated their effects, alone and in combination, on human lung carcinoma A549 cells. CIKs treated with ATRA significantly inhibited cell growth. Additionally, CIK with ATRA synergistically inhibited migration and invasiveness, colony formation of A549 and NCI-H520 cells. Furthermore, analysis of apoptosis markers Bcl-2, Bax, Survivin and cleaved Caspase-3 showed that Bcl-2 and Survivin mRNA levels significantly decreased, and that Bax mRNA significantly increased, in the CIK + ATRA-treated cells, with corresponding effects on their respective proteins. The involved mechanisms may be associated with upregulated expression of MHC class I-Related Chain (MICA) and interleukin (IL)-2. These results suggest that administration of combined CIK and ATRA is a potentially novel treatment for lung carcinoma.

Topics: Animals; Apoptosis; Biomarkers; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cytokine-Induced Killer Cells; Cytotoxicity, Immunologic; Disease Models, Animal; Histocompatibility Antigens Class I; Humans; Immunomodulation; Interleukin-2; Mice; Tretinoin

Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by cognitive impairment with neuronal loss. The number of patients suffering from AD has increased, but none of the present therapies stops the progressive symptoms in patients with AD. It has been reported that the activation of microglial cells induces harmful chronic inflammation, leading to neuronal death. Furthermore, the impairment of adult neurogenesis in the hippocampus has been observed earlier than amyloid plaque formation. Inflammatory response may lead to impaired adult neurogenesis in patients with AD. This study examines the relationship between adult neurogenesis and neuroinflammation using APPswe/PS1M146V/tauP301L (3 × Tg) mice. We observed a decline in the proliferation of neural stem cells and the occurrence of severe inflammation in the hippocampus of 3 × Tg mouse brains at 12 months of age. Previously, our research had shown an anti-inflammatory effect of all-trans retinoic acid (ATRA) in the 3 × Tg mouse brain. We found that ATRA has effects on the recovery of proliferative cells along with suppression of activated microglia in the hippocampus. These results suggest that the inhibition of microglial activation by ATRA leads to recovery of adult neurogenesis in the hippocampus in an AD mouse model. © 2016 Wiley Periodicals, Inc.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Antineoplastic Agents; Calcium-Binding Proteins; Cell Proliferation; Disease Models, Animal; Female; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Hippocampus; Humans; Male; Mice; Mice, Transgenic; Microfilament Proteins; Microglia; Mutation; Neural Stem Cells; tau Proteins; Tretinoin

To characterize the prenatal and postnatal craniofacial bone development in mouse model of all-trans retinoic acid (ATRA) exposure at different ages by a quantitative and morphological analysis of skull morphology.. Pregnant mice were exposed to ATRA at embryonic day 10 (E10) and 13 (E13) by oral gavage. Skulls of mice embryos at E19.5 and adult mice at postnatal day 35 (P35) were collected for high-resolution microcomputed tomography (microCT) imaging scanning and section HE staining. Reconstruction and measurement of mouse skulls were performed for prenatal and postnatal analysis of the control and ATRA-exposed mice.. Craniofacial malformations in mouse models caused by ATRA exposure were age dependent. ATRA exposure at E10 induced cleft palate in 81.8% of the fetuses, whereas the palatine bone of E13-exposed mice was intact. Inhibitions of maxilla and mandible development with craniofacial asymmetry induced were observed at E19.5 and P35. Compared with control and E13-exposed mice, the palatine bones of E10-exposed mice were not elevated and were smaller in dimension. Some E10-exposed mice exhibited other craniofacial abnormalities, including premature fusion of mandibular symphysis with a missing mandibular incisor and a smaller mandible. Severe deviated snouts and amorphous craniofacial suture were detected in E13-exposed mice at P35.. These morphological variations in E10- and E13-exposed mice suggested that ATRA was teratogenic in craniofacial bone development in mice and the effect was age dependent.

Topics: Age Factors; Animals; Animals, Newborn; Craniofacial Abnormalities; Disease Models, Animal; Female; Mice; Pregnancy; Radiographic Image Interpretation, Computer-Assisted; Tretinoin; X-Ray Microtomography

Stroke is the consequence of limited blood flow to the brain with no established treatment to reduce the neurological deficits. Focusing on therapeutic protocols in targeting subventricular zone (SVZ) neurogenesis has been investigated recently. This study was designed to evaluate the effects of retinoic acid (RA)-pretreated Wharton's jelly mesenchymal stem cells (WJ-MSCs) in combination with triiodothyronine (T3) in the ischemia stroke model. Male Wistar rats were used to induce focal cerebral ischemia by middle cerebral artery occlusion (MCAO). There were seven groups of six animals: Sham, Ischemic, WJ-MSCs, RA-pretreated WJ-MSCs, T3, WJ-MSCs +T3, and RA-pretreated WJ-MSCs + T3. The treatment was performed at 24 h after ischemia, and animals were sacrificed one week later for assessments of retinoid X receptor β (RXRβ), brain-derived neurotrophic factor (BDNF), Sox2 and nestin in the SVZ. Pro-inflammatory cytokines in sera were measured at days four and seven after ischemia. RXRβ, BDNF, Sox2 and nestin had the significant expressions in gene and protein levels in the treatment groups, compared with the ischemic group, which were more vivid in the RA-pretreated WJ-MSCs + T3 (p ≤ 0.05). The same trend was also resulted for the levels of TNF-α and IL-6 at four days after ischemia (p ≤ 0.05). In conclusion, application of RA-pretreated WJ-MSCs + T3 could be beneficial in exerting better neurotrophic function probably via modulation of pro-inflammatory cytokines.

Topics: Animals; Brain-Derived Neurotrophic Factor; Cytokines; Disease Models, Animal; Infarction, Middle Cerebral Artery; Lateral Ventricles; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Nestin; Rats; Rats, Wistar; Retinoid X Receptor beta; SOXB1 Transcription Factors; Stroke; Tretinoin; Triiodothyronine; Wharton Jelly

Immune-modulating drugs that target myeloid-derived suppressor cells or stimulate natural killer T cells have been shown to reduce mycobacterial loads in tuberculosis (TB). We aimed to determine if a combination of these drugs as adjunct immunotherapy to conventional antibiotic treatment could also increase therapeutic efficacy against TB. In our model of pulmonary TB in mice, we applied treatment with isoniazid, rifampicin, and pyrazinamide for 13 weeks alone or combined with immunotherapy consisting of all-trans retinoic acid, 1,25(OH)

Topics: Animals; Anti-Bacterial Agents; Antitubercular Agents; Cholecalciferol; Combined Modality Therapy; Disease Models, Animal; Female; Galactosylceramides; Immunity, Cellular; Immunotherapy; Lung; Mice, Inbred BALB C; Recurrence; Tretinoin; Tuberculosis; Tumor Necrosis Factor-alpha

Medial ganglionic eminence (MGE) progenitors give rise to inhibitory interneurons and may serve as an alternative cell source for large-scale cell transplantation for epilepsy after in vitro expansion. We investigated whether modifications in the culture medium of MGE neurospheres affect neuronal differentiation and expression of MGE-specific genes. In vivo, we compared anticonvulsant effects and cell differentiation pattern among neurospheres grown in different culture media and compared them with freshly harvested MGE cells.. We used four variations of cell culture: standard, containing growth factors (EGF/FGF-2) (GF); addition of retinoic acid (GF-RA); withdrawal of EGF/FGF-2 (WD); and addition of retinoic acid and withdrawal of EGF/FGF-2 (WD-RA). Based on in vitro results neurosphere-grown (WD-RA or GF conditions) or fresh MGE cells were transplanted into the hippocampus.. In vitro WD-RA showed increased neuronal population and higher expression of Dlx1, Nkx2.1, and Lhx6 genes in comparison with GF culture condition. After transplantation, fresh MGE cells and neurospheres (GF) showed anticonvulsant effects. However, fresh MGE cells differentiated preferentially into inhibitory neurons, while GF gave rise to glial cells.. We conclude that freshly isolated and neurosphere-grown MGE cells reduced seizures by different mechanisms (inhibitory interneurons vs. astrocytes). Fresh MGE cells appear more appropriate for cell therapies targeting inhibitory interneurons for conferring anticonvulsant outcomes.

Topics: Animals; Cell Differentiation; Cells, Cultured; Creatine; Disease Models, Animal; Embryo, Mammalian; Epidermal Growth Factor; Epilepsy; Fibroblast Growth Factor 2; Glial Fibrillary Acidic Protein; LIM-Homeodomain Proteins; Median Eminence; Muscarinic Agonists; Neurons; Neuropeptide Y; Parvalbumins; Phosphopyruvate Hydratase; Pilocarpine; Rats; Rats, Sprague-Dawley; Tretinoin

Recently, we demonstrated that treatment with all- trans-retinoic acid (tRA) induced a paradoxical effect on immune activation during the development of autoimmune lupus. Here, we further describe its negative effects on mediating neuroinflammation and neurodegeneration. Female MRL/lpr mice were orally administered tRA or VARA (retinol mixed with 10% tRA) from 6 to 14 weeks of age. Both treatments had a significant effect on brain weight, which correlated with histopathological evidence of focal astrogliosis, meningitis, and ventriculitis. Infiltration of CD138- and Iba1-positve immune cells was observed in the third ventricle and meninges of treated mice that co-labeled with ICAM-1, indicating their inflammatory nature. Increased numbers of circulating plasma cells, autoantibodies, and total IgG were also apparent. IgG and C3 complement deposition in these brain regions were also prominent as was focal astrogliosis surrounding the ventricular lining and meninges. Using Fluoro-Jade staining, we further demonstrate that neuroinflammation was accompanied by neurodegeneration in the cortex of treated mice compared with vehicle controls. These findings indicate that vitamin A exposure exacerbates the immunogenic environment of the brain during the onset of systemic autoimmune disease. Vitamin A may therefore compromise the immuno-privileged nature of the central nervous system under a predisposed immunogenic environment.

Topics: Animals; Autoantibodies; Brain; Complement C3; Disease Models, Animal; Female; Immunoglobulin G; Lupus Erythematosus, Systemic; Meningitis; Mice, Inbred MRL lpr; Tretinoin; Vitamin A; Vitamins

Erythropoietin (EPO), an essential stimulator of erythropoiesis produced by the fetal liver, is important both in vascular remodeling and modulation of the endothelial response in the pulmonary vasculature. In addition, EPO guides alveolar development, along with retinoic acid (RA). EPO is a direct target of RA, and the retinoid pathway is altered in the nitrofen-induced congenital diaphragmatic hernia (CDH) model. In the present study, we tested the hypothesis that the synthesis of EPO is suppressed in a rat model of CDH.. Pregnant rats were treated with either nitrofen or vehicle on gestational day 9 (D9). Fetuses were sacrificed on D19 and D21 and divided into control and CDH groups. Immunohistochemistry and quantitative real-time polymerase chain reaction (RT-PCR) were performed to determine the expression of EPO in the fetal liver and kidney. We also estimated the expression of EPO receptor in the fetal lung.. The relative EPO mRNA expression in the liver on D19 and in the kidney on D21 were significantly lower in the CDH group than in the controls (P = 0.0008 and P = 0.0064, respectively). In addition, the results of immunohistochemistry supported the findings from the RT-PCR analysis. No significant changes were noted in the expression pattern or EPO receptor levels in the fetal lungs of the CDH group compared to the controls.. Our results reveal the suppressed EPO synthesis in the CDH fetus, which may contribute to the pathogenesis of lung hypoplasia and modification of pulmonary vasculature in the CDH rat model. Pediatr Pulmonol. 2017;52:606-615. © 2016 Wiley Periodicals, Inc.

Topics: Animals; Disease Models, Animal; Erythropoietin; Female; Gene Expression Regulation, Developmental; Hernias, Diaphragmatic, Congenital; Lung; Phenyl Ethers; Pregnancy; Rats; Rats, Sprague-Dawley; Tretinoin

Mutations in the CYP1B1 gene are the most commonly identified genetic causes of primary infantile-onset glaucoma. Despite this disease association, the role of CYP1B1 in eye development and its in vivo substrate remain unknown. In the present study, we used zebrafish to elucidate the mechanism by which cyp1b1 regulates eye development.. Zebrafish eye and neural crest development were analyzed using live imaging of transgenic zebrafish embryos, in situ hybridization, immunostaining, TUNEL assay, and methylacrylate sections. Cyp1b1 and retinoic acid (RA) levels were genetically (morpholino oligonucleotide antisense and mRNA) and pharmacologically manipulated to examine gene function.. Using zebrafish, we observed that cyp1b1 was expressed in a specific spatiotemporal pattern in the ocular fissures of the developing zebrafish retina and regulated fissure patency. Decreased Cyp1b1 resulted in the premature breakdown of laminin in the ventral fissure and altered subsequent neural crest migration into the anterior segment. In contrast, cyp1b1 overexpression inhibited cell survival in the ventral ocular fissure and prevented fissure closure via an RA-independent pathway. Cyp1b1 overexpression also inhibited the ocular expression of vsx2, pax6a, and pax6b and increased the extraocular expression of shha. Importantly, embryos injected with human wild-type but not mutant CYP1B1 mRNA also showed colobomas, demonstrating the evolutionary and functional conservation of gene function between species.. Cyp1b1 regulation of ocular fissure closure indirectly affects neural crest migration and development through an RA-independent pathway. These studies provide insight into the role of Cyp1b1 in eye development and further elucidate the pathogenesis of primary infantile-onset glaucoma.

Topics: Animals; Animals, Genetically Modified; Cytochrome P-450 CYP1B1; Disease Models, Animal; Eye; Gene Expression Regulation, Developmental; In Situ Hybridization; In Situ Nick-End Labeling; Mutation; Neural Crest; Organogenesis; RNA, Messenger; Tretinoin; Zebrafish

Olumacostat glasaretil (OG) is a small molecule inhibitor of acetyl coenzyme A (CoA) carboxylase (ACC), the enzyme that controls the first rate-limiting step in fatty acid biosynthesis. Inhibition of ACC activity in the sebaceous glands is designed to substantially affect sebum production, because over 80% of human sebum components contain fatty acids. OG inhibits de novo lipid synthesis in primary and transformed human sebocytes. TrueMass Sebum Panel analyses showed a reduction in saturated and monounsaturated fatty acyl chains across lipid species, including di- and triacylglycerols, phospholipids, cholesteryl esters, and wax esters in OG-treated sebocytes. There was no shift to shorter acyl chain lengths observed, suggesting that the fatty acid chain elongation process was not affected. OG is a pro-drug of the ACC inhibitor 5-(tetradecyloxy)-2-furoic acid and was designed to enhance delivery in vivo. Topical application of OG but not 5-(tetradecyloxy)-2-furoic acid significantly reduced hamster ear sebaceous gland size, indicating that this pro-drug approach was critical to obtain the desired activity in vivo. High-performance liquid chromatography analyses of hamster ear extracts showed that OG treatment increased ACC levels and the ratio of acetyl-CoA to free CoA in these animals, indicating increased fatty acid oxidation. These changes are consistent with ACC inhibition. Matrix-assisted laser desorption/ionization imaging showed that OG applied onto Yorkshire pig ears accumulated in sebaceous glands relative to the surrounding dermis. Sebaceous gland ACC represents an attractive therapeutic target given its central role in formation of sebum, a key factor in acne pathogenesis.

Topics: Acetyl-CoA Carboxylase; Acne Vulgaris; Administration, Cutaneous; Animals; Cricetinae; Disease Models, Animal; Humans; Keratolytic Agents; Prodrugs; Sebaceous Glands; Sebum; Tretinoin

Hepatocellular carcinoma (HCC) is one of the most prevalent and malignant cancers with high inter- and intra-tumor heterogeneity. A central common signaling mechanism in cancer is proline-directed phosphorylation, which is further regulated by the unique proline isomerase Pin1. Pin1 is prevalently overexpressed in human cancers including ~70% of HCC, and promotes tumorigenesis by activating multiple cancer-driving pathways. However, it was challenging to evaluate the significance of targeting Pin1 in cancer treatment until the recent identification of all-trans retinoic acid (ATRA) as a Pin1 inhibitor. Here we systematically investigate functions of Pin1 and its inhibitor ATRA in the development and treatment of HCC. Pin1 knockdown potently inhibited HCC cell proliferation and tumor growth in mice. ATRA-induced Pin1 degradation inhibited the growth of HCC cells, although at a higher IC50 as compared with breast cancer cells, likely due to more active ATRA metabolism in liver cells. Indeed, inhibition of ATRA metabolism enhanced the sensitivity of HCC cells to ATRA. Moreover, slow-releasing ATRA potently and dose-dependently inhibited HCC growth in mice. Finally, chemical or genetic Pin1 ablation blocked multiple cancer-driving pathways simultaneously in HCC cells. Thus, targeting Pin1 offers a promising therapeutic approach to simultaneously stop multiple cancer-driving pathways in HCC.

Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Enzyme Inhibitors; Gene Knockdown Techniques; Humans; Liver Neoplasms; Mice; NIMA-Interacting Peptidylprolyl Isomerase; Proteolysis; Signal Transduction; Tretinoin; Xenograft Model Antitumor Assays

This study investigated the correlation between differentially expressed proteins in amniotic fluid (AF) and cleft palate induced by all-trans retinoic acid (atRA), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in mice. Seven proteins were differentially expressed at embryonic day (E) 16.5 in atRA and control groups as revealed by label-based mouse antibody array. Enzyme-linked immunosorbent assay was further used to detect the expression levels of these proteins in AF from E13.5 to E16.5 in atRA, TCDD, and control groups. The cleft palate groups showed lower concentrations of receptor for advanced glycation end products (RAGE) and epiregulin at E16.5. RAGE immunostaining obviously decreased in palatal tissue sections obtained from E14.5 to E16.5 in the cleft palate groups as revealed by immunohistochemistry. These findings indicate that reduced levels of RAGE and epiregulin in AF are correlated to chemically induced cleft palate in mice.

Topics: Amniotic Fluid; Animals; Biomarkers; Cleft Palate; Disease Models, Animal; Epiregulin; Female; Gestational Age; Mice, Inbred C57BL; Palate; Polychlorinated Dibenzodioxins; Pregnancy; Receptor for Advanced Glycation End Products; Tretinoin

To observe the preventive and therapeutic effects of diosgenin on retinoic acid-induced osteoporosis in rats.. A total 50 Sprague-Dawley rats were randomly divided into 5 groups: control group, model group (osteoporosis rats), low (10 mg kg(-1)), middle (30 mg kg(-1)), and high-dose diosgenin (90 mg kg(-1))-treated groups. The osteoporosis rats model was induced by retinoic acid. The BMD and physical parameters of femoral including length, wet weight, and dry weight in each group were measured. The hematoxylin-eosin staining was used for bone histomorphology analysis. Besides, the bone calcium (Ca) and phosphorus (P) contents were measured. In order to detect the biochemical index in different treatment groups, the serum tartrate-resistant acid phosphatase (TRAP), alkaline phosphatase (ALP), estradiol, and osteocalcin were compared among different groups.. The osteoporosis rat model was successfully induced by retinoic acid. Compared with the model group, the lessening of femoral length and weight and the loss of BMD were significantly improved in diosgenin groups. Both contents of Ca and P were much more increased when induced by retinoic acid (p < 0.05). The estradiol and osteocalcin levels in the middle and high-dose treatment groups were significantly higher than that of the model group, while the ALP and TRAP levels were much lower than the model group (p < 0.05).. Diosgenin can prevent the loss of bone in experimental rats. The mechanism may be that it improves the level of estrogenic hormone of estradiol and inhibits the high bone turnover.

Topics: Animals; Bone Density; Diosgenin; Disease Models, Animal; Female; Osteoporosis; Rats; Rats, Sprague-Dawley; Tretinoin

There is growing evidence of ongoing, in utero neurological damage in fetuses with myelomeningocele (MMC). Phospholipase A2 (PLA2) has known neurotoxic properties and is predominantly present in its secretory isoform (sPLA2) in meconium, the passage of which is increased in MMC fetuses. The objective of this study was to determine if amniotic fluid (AF) levels of PLA2 are elevated in a rat model of MMC.. Timed pregnant Sprague-Dawley rats were gavage fed 60 mg/kg/bodyweight retinoic acid (RA) in olive oil at embryonic day 10 (E10). Amniocentesis was performed at multiple gestational time points on MMC fetuses, RA-exposed fetuses without MMC and control fetuses. AF PLA2 levels were analyzed by a fluorescent enzyme activity assay. PLA2 isoforms were determined by measuring activity in the presence of specific inhibitors.. There was no difference in AF PLA2 activity between groups on E15. PLA2 activity was significantly increased in MMC fetuses on E17, E19 and E21 (p < 0.001). Secretory PLA2 primarily accounted for the overall greater activity.. PLA2 levels are elevated in the AF of fetal rats with MMC and may contribute to ongoing neural injury. This pathway may be a useful drug target to limit ongoing damage and better preserve neurologic function.

Topics: Amniotic Fluid; Animals; Disease Models, Animal; Female; Fetal Diseases; Fluorescent Antibody Technique; Isoenzymes; Meningomyelocele; Phospholipases A2, Secretory; Pregnancy; Rats; Rats, Sprague-Dawley; Tretinoin

The association between Wnt genes and neural tube defects (NTDs) is recognized, however, it remains to be fully elucidated. Our previous study demonstrated that epigenetic mechanisms are affected in human NTDs. Therefore, the present study aimed to evaluate whether Wnt2b and Wnt7b are susceptible to abnormal epigenetic modification in NTDs, using chromatin immunoprecipitation assays to evaluate histone enrichments and the MassARRAY platform to detect the methylation levels of target regions within Wnt genes. The results demonstrated that the transcriptional activities of Wnt2b and Wnt7b were abnormally upregulated in mouse fetuses with NTDs and, in the GC‑rich promoters of these genes, histone 3 lysine 4 (H3K4) acetylation was enriched, whereas H3K27 trimethylation was reduced. Furthermore, several CpG sites in the altered histone modification of target regions were significantly hypomethylated. The present study also detected abnormal epigenetic modifications of these Wnt genes in human NTDs. In conclusion, the present study detected abnormal upregulation in the levels of Wnt2b and Wnt7b, and hypothesized that the alterations may be due to the ectopic opening of chromatin structure. These results improve understanding of the dysregulation of epigenetic modification of Wnt genes in NTDs.

Topics: Animals; Chromatin Immunoprecipitation; Disease Models, Animal; DNA Methylation; Embryo, Mammalian; Epigenesis, Genetic; Female; Gene Expression Regulation, Developmental; Glycoproteins; Histones; Humans; Male; Mice, Inbred C57BL; Neural Tube Defects; Promoter Regions, Genetic; Protein Processing, Post-Translational; Proto-Oncogene Proteins; Spinal Dysraphism; Tretinoin; Wnt Proteins

To determine the effect of 9-cis retinoic acid (9-cis RA) on postsurgical lymphedema.. 9-cis RA promotes lymphangiogenesis in vitro and in vivo and has promise as a therapeutic agent to limit the development of postsurgical lymphedema.. Lymphedema was induced in the right hind limb after a single fraction of 20 Gy radiation, popliteal lymphadenectomy, and lymphatic vessel ablation. Postoperatively, mice were randomly divided in to 2 groups that received daily intraperitoneal injections of either (1) an oil-based vehicle solution (control) or (2) 0.08 mg/kg of 9-cis RA dissolved in a vehicle solution. Outcome measures included paw thickness, lymphatic drainage, and lymphatic vessel density as measured by podoplanin immunohistochemistry and whole mount skin analysis.. Using our combined injury protocol, postsurgical lymphedema was observed 89% of the time. 9-cis RA-treated animals had less early postsurgical edema and significantly less paw lymphedema compared with vehicle-treated animals at all time-points (P < 0.001). 9-cis RA-treated animals had significantly faster lymphatic drainage as measured by indocyanine green clearance and increased lymphatic vessel density as measured by podoplanin immunohistochemistry (P < 0.001) and whole mount skin analysis (P < 0.05).. We have developed a highly reproducible model of secondary lymphedema and have demonstrated that 9-cis RA significantly prevents postsurgical lymphedema. Treatment with 9-cis RA is associated with increased lymphatic clearance and lymphangiogenesis. Because 9-cis RA (alitretinoin) is already approved for clinical use by the US Food and Drug Administration for other conditions, it has the potential to be repurposed as a preventative agent for postsurgical lymphedema in humans.

Topics: Alitretinoin; Animals; Antineoplastic Agents; Disease Models, Animal; Lymphangiogenesis; Lymphedema; Male; Mice; Mice, Transgenic; Postoperative Complications; Tretinoin

Low pulmonary retinol levels and disrupted retinoid signaling pathway (RSP) have been implicated in the pathogenesis of congenital diaphragmatic hernia (CDH) and associated pulmonary hypoplasia (PH). It has been demonstrated that nitrofen disturbs the main retinol-binding protein (RBP)-dependent trophoblastic retinol transport. Several studies have demonstrated that prenatal treatment with retinoic acid (RA) can reverse PH in the nitrofen-induced CDH model. We hypothesized that maternal administration of RA can increase trophoblastic RBP-dependent retinol transport in a nitrofen model of CDH.. Pregnant rats were treated with nitrofen or vehicle on gestational day 9 (D9) and sacrificed on D21. RA was given i.p. on D18, D19, and D20. Retinol and RA levels were measured using high-performance liquid chromatography. Immunohistochemistry was performed to evaluate trophoblastic expression of RBP. Expression levels of the primary RSP genes were determined using quantitative real-time PCR and immunohistochemistry.. Markedly increased trophoblastic RBP immunoreactivity was observed in CDH+RA compared to CDH. Significantly increased serum and pulmonary retinol and RA levels were detected in CDH+RA compared to CDH. Pulmonary expression of RSP genes and proteins were increased in CDH+RA compared to CDH.. Increased trophoblastic RBP expression and retinol transport after antenatal administration of RA suggest that retinol-triggered RSP activation may attenuate CDH-associated PH by elevating serum and pulmonary retinol levels.

Topics: Animals; Biological Transport; Disease Models, Animal; Female; Fetal Weight; Hernias, Diaphragmatic, Congenital; Lung; Phenyl Ethers; Pregnancy; Rats; Retinol-Binding Proteins; Tretinoin; Trophoblasts; Vitamin A

The gut microbiota modulates the autoimmune pathogenesis of type 1 diabetes (T1D) via mechanisms that remain largely unknown. The inflammasome components are innate immune sensors that are highly influenced by the gut environment and play pivotal roles in maintaining intestinal immune homeostasis. In this study we show that modifications of the gut microbiota induced by oral treatment with Lactobacillaceae-enriched probiotic VSL#3, alone or in combination with retinoic acid (RA), protect NOD mice from T1D by affecting inflammasome at the intestinal level. In particular, we show that VSL#3 treatment inhibits IL-1β expression while enhancing release of protolerogenic components of the inflammasome, such as indoleamine 2,3-dioxygenase (IDO) and IL-33. Those modifications of the intestinal microenvironment in VSL#3-treated NOD mice modulate gut immunity by promoting differentiation of tolerogenic CD103(+) DCs and reducing differentiation/expansion of Th1 and Th17 cells in the intestinal mucosa and at the sites of autoimmunity, that is, within the pancreatic lymph nodes (PLN) of VSL#3-treated NOD mice. Our data provide a link between dietary factors, microbiota composition, intestinal inflammation, and immune homeostasis in autoimmune diabetes and could pave the way for new therapeutic approaches aimed at changing the intestinal microenvironment with probiotics to counterregulate autoimmunity and prevent T1D.

Topics: Administration, Oral; Age Factors; Animals; Autoimmunity; Cellular Microenvironment; Diabetes Mellitus, Type 1; Disease Models, Animal; Gastrointestinal Microbiome; Indoleamine-Pyrrole 2,3,-Dioxygenase; Inflammasomes; Interleukin-1beta; Interleukin-33; Intestines; Lactobacillaceae; Mice, Inbred NOD; Probiotics; Th1 Cells; Th17 Cells; Tretinoin

Aged and adult populations have differences in the structural, biological, and healing properties of skin. Comparative studies of healing under the influence of retinoids in both these populations are very important and, to the best of our knowledge, have not been performed to date. The purpose of this study was to compare the activities of topical tretinoin in aged and adult animal models of wound healing by secondary intention. Male aged rats (24 months old, n = 7) and adult rats (6 months old, n = 8) were used. The rats were assigned to the following groups according to the dates on which wound samples were excised (day 14 or 21 after model creation): treated group, control group, and naive group. Topical application of tretinoin cream was used only on the proximal wound and was applied daily for 7 days. Wound healing areas were measured using metal calipers, and morphological analysis was performed. Slides were stained with Hematoxylin and Eosin, Masson's trichrome, and periodic acid-Schiff stains. Statistical analysis adopted a 5% coefficient for rejection of the null hypothesis. Although aged animals showed skin repair, complete reepithelialization was found on day 21 in some animals of both groups (treated and control). In aged rats, the wound area was significantly smaller in treated wounds than in untreated wounds, resulting in a larger scar area compared with the adult group. When treated wounds were compared, no differences were found between the wound areas in adult and aged rats. As expected, the collagen concentration was higher in normal skin from adult rats than in normal skin from aged animals, but there was no difference when aged skin was treated with tretinoin. These results indicate that tretinoin increases collagen synthesis in aged skin and returns the healing process to a normal state of skin healing.

Topics: Animals; Collagen; Disease Models, Animal; Granulation Tissue; Keratolytic Agents; Male; Rats; Rats, Wistar; Re-Epithelialization; Skin Aging; Tretinoin; Wound Healing; Wounds and Injuries

We examined the effect of all-trans retinoic acid on collagen degradation mediated by corneal fibroblasts.. Rabbit corneal fibroblasts were cultured with or without all-trans retinoic acid in a three-dimensional collagen gel, and the extent of collagen degradation was determined by measurement of hydroxyproline in acid hydrolysates of culture supernatants. Matrix metalloproteinase expression was examined by immunoblot analysis and gelatin zymography. The abundance and phosphorylation state of the endogenous nuclear factor-kappaB inhibitor IκB-α were examined by immunoblot analysis. Corneal ulceration was induced by injection of lipopolysaccharide into the central corneal stroma of rabbits and was assessed by observation with a slitlamp microscope.. All-trans retinoic acid inhibited interleukin-1β-induced collagen degradation by corneal fibroblasts in a concentration- and time-dependent manner. It also attenuated the release and activation of matrix metalloproteinases as well as the phosphorylation and degradation of IκB-α induced by interleukin-1β in these cells. Topical application of all-trans retinoic acid suppressed corneal ulceration induced by injection of lipopolysaccharide into the corneal stroma.. All-trans retinoic acid inhibited collagen degradation mediated by corneal fibroblasts exposed to interleukin-1β, with this effect being accompanied by suppression of nuclear factor-kappaB signalling as well as of matrix metalloproteinase release and activation in these cells. All-trans retinoic acid also attenuated lipopolysaccharide-induced corneal ulceration in vivo. Our results therefore suggest that all-trans retinoic acid might prove effective for the treatment of patients with corneal ulceration.

Topics: Animals; Cells, Cultured; Collagen; Corneal Keratocytes; Corneal Ulcer; Disease Models, Animal; Dose-Response Relationship, Drug; Hydroxyproline; I-kappa B Proteins; Immunoblotting; Immunoenzyme Techniques; Interleukin-1beta; Keratolytic Agents; Lipopolysaccharides; Male; Matrix Metalloproteinases; NF-kappa B; Phosphorylation; Rabbits; Tretinoin

Gastroenteritis is a global burden; it's the major cause of morbidity and mortality both in adults and children of developing countries. Salmonella is one of the leading causes of bacteria-mediated gastroenteritis and due to its increasing multidrug antibiotic resistance; Salmonella-mediated gastroenteritis is difficult to control. Retinoic acid, the biologically active agent of vitamin A has an anti-inflammatory effect on experimental colitis. In this study we have shown All trans retinoic acid (ATRA) treatment down regulates Salmonella-mediated colitis in a murine model. Macroscopic signs of inflammation such as decrease in body weight and cecum weight, shorter length of proximal colon and pathological score of colitis were observed less in ATRA treated mice than in a vehicle control group. ATRA treatment not only reduced pro-inflammatory cytokine responses, such as TNF-α, IL-6, IL-1β, IFN-γ and IL-17 production but also increased IL-10 response in the supernatant of intestinal tissue. Results also suggested that ATRA treatment enhances the number of FoxP3-expressing T regulatory cells in MLN and also decreases bacterial load in systemic organs. We concluded that ATRA treatment indeed reduces Salmonella Typhimurium-mediated gastroenteritis in mice, suggesting it could be an important part of an alternative therapeutic approach to combat the disease.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Cytokines; Disease Models, Animal; Forkhead Transcription Factors; Gastroenteritis; Humans; Inflammation Mediators; Male; Mice; Mice, Inbred BALB C; Salmonella typhi; T-Lymphocytes, Regulatory; Tretinoin

Chemokines have been recently recognized to play a role in chronic pain syndromes' pathophysiology. This study investigated the role of monocyte chemoattractant protein-1 (MCP-1), stromal cell derived factor-1 (SDF-1), and retinoic acid (RA) as targets for the therapeutic approach of neuropathic pain.. A chronic constriction injury (CCI) model of neuropathic pain by unilateral ligation of left sciatic nerve was performed in adult female Wistar rats. The effects of doxycycline (Dox, 50 mg/kg/day i.p. for 7 days), single dose of bicyclam (5 mg/kg i.p.), RA (15 mg/kg/day i.p. for 7 days), and their combination(s) on behavioral tests of nociception (Von Frey filaments; paw pressure test) on days 0, 1, 3, 5, and 7 of operation were studied. Serum concentrations of MCP-1 and SDF-1 were measured by ELISA. Histological examination of the sciatic nerve was investigated.. CCI of sciatic nerve significantly induced mechanical allodynia and hyperalgesia and an increase of MCP-1 and SDF-1 serum levels. Dox-treated groups (Dox, Dox+bicyclam, Dox+RA, Dox+bicyclam+RA) and bicyclam-treated groups (bicyclam, Dox+bicyclam, bicyclam+RA, Dox+bicyclam+RA) attenuated CCI-induced behavioral and biochemical changes. RA inhibited CCI-induced mechanical hyperalgesia but produced a time-dependent reversal of allodynia. Histological findings showed degenerative changes of sciatic nerve after CCI that were partially recovered in Dox-treated groups.. These findings demonstrate an association between serum MCP-1 and SDF-1 concentrations and behavioral manifestations of neuropathic pain. RA administration decreased neuropathic pain (antihyperalgesic effect) but did not cause any improvement in sciatic nerve tissues, either alone or in combination with chemokine antagonists. Thus, chemokines may serve as potential targets for drug development in neuropathic pain treatment.

Topics: Animals; Benzylamines; Chemokine CCL2; Chemokine CXCL12; Cyclams; Disease Models, Animal; Doxycycline; Female; Heterocyclic Compounds; Hyperalgesia; Neuralgia; Nociception; Pain Measurement; Pain Threshold; Rats; Rats, Wistar; Sciatic Nerve; Tretinoin

To investigate the effect of combined prenatal treatment with retinoic acid (RA) and tracheal occlusion (TO) on the pulmonary vascular morphology and expression of vascular endothelial growth factors (VEGF) and its receptors in a rat model of congenital diaphragmatic hernia (CDH).. Rats were given nitrofen at 9 days of gestation followed by no treatment (CDH), RA (CDH + RA), TO (CDH + TO), or both (CDH + RA + TO) (n = 16). We measured the median wall thickness of the pulmonary arterioles (MWT) and analyzed the expression of VEGF and its receptors (VEGFR1 and VEGFR2).. Compared to control animals, CDH had increased MWT (44 ± 15 vs. 58 ± 7; p < 0.05) and decreased expression of VEGF, VEGFR1, and VEGFR2 (p < 0.05). Treatment with RA or TO alone, and RA + TO reduced the MWT (46 ± 9, 42 ± 11, 46 ± 8, respectively) and improved the expression of VEGF, VEGFR1, and VEGFR2 compared to CDH (p < 0.05). However, the combination of RA + TO did not confer additional benefit in the reduction of the MWT or in increasing the VEGF and its receptors compared to either treatment alone.. Antenatal treatment with either RA or TO improved the MWT and expression of VEGF and its receptors in a CDH rat model. However, combined treatment with RA + TO was not superior to either treatment alone.

Topics: Animals; Antineoplastic Agents; Balloon Occlusion; Disease Models, Animal; Female; Hernias, Diaphragmatic, Congenital; Pregnancy; Pregnancy, Animal; Rats; Rats, Sprague-Dawley; Trachea; Tretinoin

Acute promyelocytic leukemia (APL) is a M3 subtype of acute myeloid leukemia (AML). Promyelocytic leukemia (PML)-retinoic acid receptor α (RARα) translocation generally occurs in APL patients and makes APL unique both for diagnosis and treatment. However, some conventional drugs like all-transretinoic acid (ATRA) and arsenic trioxide (ATO), as the preferred ones for APL therapy, induce irreversible resistance and responsible for clinical failure of complete remission. Herein, we screened a library of novel chemical compounds with structural diversity and discovered a novel synthetic small compound, named LG-362B, specifically inhibited the proliferation of APL and induced apoptosis. Notably, the differentiation arrest was also relieved by LG-362B in cultured APL cells and APL mouse models. Moreover, LG-362B overcame the ATRA resistance on cellular differentiation and transplantable APL mice. These positive effects were driven by caspases-mediated degradation of PML-RARα when treated with LG-362B, making it specific to APL and reasonable for ATRA resistance relief. We propose that LG-362B would be a potential candidate agent for the treatment of the relapsed APL with ATRA resistance in the future.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carbolines; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Drug Resistance, Neoplasm; Humans; Leukemia, Promyelocytic, Acute; Mice; Oncogene Proteins, Fusion; Small Molecule Libraries; Tretinoin; Tumor Cells, Cultured

Immunoglobulin (Ig) A nephropathy (IgAN) is the xFB01;nding of immune deposits predominantly containing polymeric IgA in the glomerular mesangium on renal biopsy. Increasing evidence suggested that retinoic acid (RA) signaling selectively induces IgA isotype switching and basic leucine zipper transcription factor, ATF-like (BATF) controls the global regulators of class switch recombination (CSR) in lymphocytes. Great effort has been paid to identify whether impaired immune regulation along the 'mucosa-bone marrow (BM) axis' play an important role in the pathogenesis of IgAN.. The aim of the study was to investigate the expression of all-trans-RA (ATRA) and BATF, and to identify their impact on IgA CSR in IgAN patients and rat animal models. Blood samples and tonsillar tissue specimens were obtained from 22 patients with IgAN and 24 patients with chronic tonsillitis as control.. Immunohistochemical, RT-PCR and western blotting examination revealed that RA signaling and BATF productions are activated in IgAN patients compared with controls. Lipopolysaccharide and α-hemolytic streptococcus stimulation upregulated RA receptor (RAR) and BATF expression, promote IgA CSR and ATRA productions in tonsil mononuclear cells. RAR alpha (RARα) or BATF siRNA decreases IgA expression. We also built IgAN rat models and found that RARα, BATF and activation-induced cytidine deaminase were upregulated in the peripheral blood, spleen and BM. With ATRA (500 μg/kg body weight) treatment for 8 weeks, IgA deposition on glomeruli and mesangial cells proliferation increased. It also revealed that ATRA activated BATF and IgA CSR in vivo.. These data point toward the role of RA signaling together with BATF in IgA CSR of IgAN, and the data also support the notion that mucosal immunization with neoantigen results in impaired mucosal and systemic IgA responses.

Topics: Adolescent; Adult; Animals; Basic-Leucine Zipper Transcription Factors; Bone Marrow; Disease Models, Animal; Female; Glomerulonephritis, IGA; Humans; Immunoglobulin A; Immunoglobulin Class Switching; Kidney Glomerulus; Lipopolysaccharides; Male; Mesangial Cells; Middle Aged; Palatine Tonsil; Primary Cell Culture; Random Allocation; Rats, Sprague-Dawley; Retinoic Acid Receptor alpha; Signal Transduction; Spleen; Tretinoin; Young Adult

The digestive tract is the entry site for transmissible gastroenteritis virus (TGEV). TGEV transmission can be prevented if local immunity is established with increased lymphocytes. The current parenteral mode of vaccination stimulates systemic immunity well, but it does not induce sufficient mucosal immunity. Retinoic acid (RA) plays an important role in the induction of cells that imprint gut-homing molecules. We examined whether RA assist parenteral vaccination of pigs could improve mucosal immunity. We demonstrated that elevated numbers of gut-homing CD8(+) T cells (which express α4β7 and CCR9 molecules) were presented in porcine inguinal lymph nodes and were recruited to the small intestine by RA. Intestinal mucosal immunity (IgA titre) and systemic immunity (serum IgG titre) were enhanced by RA. Therefore, we hypothesized that RA could induce DCs to form an immature mucosal phenotype and could recruit them to the small intestinal submucosa. Porcine T-cells expressed β7 integrin and CCR9 receptors and migrated to CCL25 by a mechanism that was dependent of activation by RA-pretreated DCs, rather than direct activation by RA. Together, our results provide powerful evidence that RA can assist whole inactivated TGEV (WI-TGEV) via subcutaneous (s.c.) immunization to generate intestinal immunity, and offer new vaccination strategies against TGEV.

Topics: Animals; CD8-Positive T-Lymphocytes; Chemotaxis, Leukocyte; Dendritic Cells; Disease Models, Animal; Gastroenteritis, Transmissible, of Swine; Gastrointestinal Tract; Immunity, Mucosal; Immunoglobulin A, Secretory; Immunoglobulin G; Intestinal Mucosa; Phenotype; Receptors, Lymphocyte Homing; Swine; T-Lymphocyte Subsets; Transmissible gastroenteritis virus; Tretinoin; Vaccines, Inactivated

Retinoic acid (RA) in the steady state enhances induction of Foxp3(+) regulatory T (Treg) cells and inhibits differentiation of Th1 and Th17 cells, thereby maintaining tolerance, but can in inflammatory conditions promote effector Th1 and Th17 cells that mediate inflammation. IL-17-producing γδ T cells have recently been shown to have a major pathogenic role in autoimmune diseases. Here, we examined the immunomodulatory effects of RA on γδ T cells. We found that RA had a dramatic suppressive effect on IL-17A and IL-17F production by γδ T cells stimulated with IL-1β and IL-23. RA suppressed RORγt, IL-1R and IL-23R expression in γδ T cells. Treatment of mice with RA suppressed IL-17 production by γδ T cells in vivo. Furthermore, treatment of T cells with RA attenuated their ability to induce disease in experimental autoimmune encephalomyelitis (EAE), a murine model for multiple sclerosis. This was associated with a reduction in the number of central nervous system-infiltrating γδ T cells, but also CD4(+) T cells that produced IL-17A, IL-17F or GM-CSF. Interestingly, treatment of γδ T cells with RA or removal of γδ T cells from a bulk population of T cells significantly reduced their capacity to induce EAE, demonstrating a critical role for γδ T cells in promoting pathogenic Th17 cells. Our findings demonstrate that the anti-inflammatory properties of RA are mediated in part by suppressing STAT3-mediated activation of cytokine production and cytokine receptor expression in γδ T cells, which suppresses their ability to activate Th17 cells.

Topics: Adoptive Transfer; Animals; Autoimmunity; Central Nervous System; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Immunologic Factors; Interleukin-17; Interleukin-1beta; Interleukin-23; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Receptors, Antigen, T-Cell, gamma-delta; Tretinoin

Gastric carcinoma is the third leading cause of cancer-related death worldwide. This cancer, most of the time metastatic, is essentially treated by surgery associated with conventional chemotherapy, and has a poor prognosis. The existence of cancer stem cells (CSC) expressing CD44 and a high aldehyde dehydrogenase (ALDH) activity has recently been demonstrated in gastric carcinoma and has opened new perspectives to develop targeted therapy. In this study, we evaluated the effects of all-trans-retinoic acid (ATRA) on CSCs in human gastric carcinoma. ATRA effects were evaluated on the proliferation and tumorigenic properties of gastric carcinoma cells from patient-derived tumors and cell lines in conventional 2D cultures, in 3D culture systems (tumorsphere assay) and in mouse xenograft models. ATRA inhibited both tumorspheres initiation and growth in vitro, which was associated with a cell-cycle arrest through the upregulation of cyclin-dependent kinase (CDK) inhibitors and the downregulation of cell-cycle progression activators. More importantly, ATRA downregulated the expression of the CSC markers CD44 and ALDH as well as stemness genes such as Klf4 and Sox2 and induced differentiation of tumorspheres. Finally, 2 weeks of daily ATRA treatment were sufficient to inhibit gastric tumor progression in vivo, which was associated with a decrease in CD44, ALDH1, Ki67 and PCNA expression in the remaining tumor cells. Administration of ATRA appears to be a potent strategy to efficiently inhibit tumor growth and more importantly to target gastric CSCs in both intestinal and diffuse types of gastric carcinoma.

Topics: Aldehyde Dehydrogenase; Animals; Antineoplastic Agents; Biomarkers; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Female; Humans; Hyaluronan Receptors; Immunophenotyping; Kruppel-Like Factor 4; Mice; Neoplastic Stem Cells; Spheroids, Cellular; Stomach Neoplasms; Tretinoin; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Models developed for the study of asthma mechanisms can be used to investigate new compounds with pharmacological activity against this disease. The increasing number of compounds requires a preclinical evaluation before starting the application in humans. Preclinical evaluation in animal models reduces the number of clinical trials positively impacting in the cost and in safety. In this chapter, three protocols for the study of drugs are shown: a model to investigate corticoids as a classical treatment of asthma; a protocol to test the effects of retinoic acid (RA) on asthma; and a mouse model to test new therapies in asthma as monoclonal antibodies.

Topics: Adrenal Cortex Hormones; Animals; Antibodies, Monoclonal; Asthma; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Humans; Mice; Mice, Inbred BALB C; Research Design; Tretinoin

Retinoic acid, the bioactive metabolite of beta-carotene or vitamin A, plays a pleiotropic, multifunctional role in vertebrate development. Studies in rodents revealed that a diet deficient in vitamin A results in a complex neonatal syndrome (the VAD syndrome), manifested in many organs. In humans, the function of retinoic acid (RA) extends into adulthood, where it has important roles in fertility, vision, and suppression of neoplastic growth. In recent years, it has also been suggested that retinoic acid might potentially act as a therapeutically relevant drug in attenuating or even preventing neurodegenerative diseases such as Alzheimer's disease (AD). Here, we report that VAD leads to an increase in A-beta peptide levels while only minor effects were observed on expression levels of the amyloid precursor protein (APP) processing proteinases in wild type mice. In line with these findings, rescue of hypovitaminosis reduced A-beta amount to baseline and induced sApp-alpha secretion in combination with an increase of alpha-secretase Adam10. By comparing retinoic acid treatment starting from a full nutrition status and a "VAD" situation in human neuroblastoma cells, we show that while intensities of differential gene expression were higher in replenished cells, a large overlap in AD-related, regulated genes was observed. Our data suggest that hypovitaminosis A can contribute to onset or progression of AD by increasing synthesis of A-beta peptides and that several AD-related genes such as ADAM10 or BDNF are regulated by retinoic acid. We suggest that dietary supplementation with retinoic acid derivatives is likely to have a beneficial effect on AD-pathology in individuals with hypovitaminosis and patients with normal vitamin A status.

Topics: Acitretin; ADAM10 Protein; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Animals, Newborn; Cells, Cultured; Cerebral Cortex; Disease Models, Animal; Female; Gene Regulatory Networks; Humans; Keratolytic Agents; Mice; Neuroblastoma; Neurons; Peptide Fragments; Presenilin-2; Rats, Wistar; Tretinoin; Vitamin A Deficiency

The novel human gene family encoding neuronal leucine rich repeat (NLRR) proteins were identified as prognostic markers from our previous screening of primary neuroblastoma (NB) cDNA libraries. Of the NLRR gene family members, NLRR1 and NLRR3 are associated with the regulation of cellular proliferation and differentiation, respectively. However, the functional regulation and clinical significance of NLRR2 in NB remain unclear. Here, we evaluated the differential expression of NLRR2, where high expressions of NLRR2 were significantly associated with a poor prognosis of NB (P = 0.0009), in 78 NBs. Enforced expression of NLRR2 in NB cells enhanced cellular proliferation and induced resistance to retinoic acid (RA)-mediated cell growth inhibition. In contrast, knockdown of NLRR2 exhibited growth inhibition effects and enhanced RA-induced cell differentiation in NB cells. After RA treatment, NLRR2 expression was increased and correlated with the upregulation of c-Jun, a member of the activator protein-1 (AP-1) family in NB cells. Moreover, the expressions of NLRR2 and c-Jun were suppressed by treatment with a JNK inhibitor, which ameliorated the promoter activity of the NLRR2 gene while knockdown of c-Jun reduced NLRR2 expression. We then searched AP-1 binding consensus in the NLRR2 promoter region and confirmed c-Jun recruitment at a consensus. Conclusively, NLRR2 must be an inducible gene regulated by the JNK pathway to enhance cell survival and inhibit NB cell differentiation. Therefore, NLRR2 should have an important role in NB aggressiveness and be a potential therapeutic target for the treatment of RA resistant and aggressive NB.

Topics: Animals; Cell Adhesion Molecules, Neuronal; Cell Differentiation; Cell Line, Tumor; Cell Survival; Disease Models, Animal; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Heterografts; Humans; MAP Kinase Signaling System; Mice; Neuroblastoma; Prognosis; Promoter Regions, Genetic; Protein Binding; Proto-Oncogene Proteins c-jun; RNA, Small Interfering; Stress, Physiological; Transcriptional Activation; Tretinoin

Amodiaquine (AQ) is associated with a relatively high incidence of idiosyncratic drug-induced liver injury (IDILI) and agranulocytosis. A previous study reported that a combination of high dose AQ and glutathione (GSH) depletion led to liver injury. However, the characteristics of this toxicity were very different from AQ-induced liver injury in humans. We developed a model of AQ-induced liver injury with characteristics similar to the injury in humans by treating mice with lower doses of AQ for several weeks. In this study we found that not only did GSH depletion not increase AQ covalent binding to hepatic proteins at this lower dose, but also it paradoxically prevented the liver injury. We extended the model to rats and found AQ treatment led to a mild delayed onset liver injury that resolved despite continued treatment with AQ. Immunohistochemistry indicated the presence of Kupffer cell activation, apoptosis and hepatocyte proliferation in the liver. There was also an increase in serum IL-2, IL-5, IL-9, IL-12, MCP-1 and TGFβ, but a decrease in leptin. Coincident with the elevated serum ALT, the number of liver CD4(+) T-cells, IL-17 secreting cells and TH17/Treg cells increased at Week 3 and decreased during continued treatment. Increases in NK1.1+ cells and activated M2 macrophages were also observed during liver injury. These results suggest that the outcome of the liver injury was determined by the balance between effector and regulatory cells. Co-treatment with cyclosporin prevented AQ-induced liver injury, which supports an immune mechanism. Retinoic acid (RA), which has been reported to enhance natural killer (NK) cell activity, exacerbated AQ-induced liver injury. These results suggest that AQ-induced IDILI is immune mediated and the subsequent adaptation appears to represent immune tolerance.

Topics: Agranulocytosis; Amodiaquine; Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Cyclosporine; Cytokines; Disease Models, Animal; Humans; Killer Cells, Natural; Male; Mice; Mice, Inbred C57BL; Rats; Rats, Inbred BN; Remission, Spontaneous; Spinocerebellar Degenerations; T-Lymphocytes, Regulatory; Th17 Cells; Tretinoin

Perivascular stromal cells (PSCs) are a recently identified cell type that comprises a small percentage of the platelet derived growth factor receptor-β+ cells within the CNS perivascular space. PSCs are activated following injury to the brain or spinal cord, expand in number and contribute to fibrotic scar formation within the injury site. Beyond fibrosis, their high density in the lesion core makes them a potential significant source of signals that act on neural cells adjacent to the lesion site.. Our developmental analysis of PSCs, defined by expression of Collagen1a1 in the maturing brain, revealed that PSCs first appear postnatally and may originate from the meninges. PSCs express many of the same markers as meningeal fibroblasts, including expression of the retinoic acid (RA) synthesis proteins Raldh1 and Raldh2. Using a focal brain ischemia injury model to induce PSC activation and expansion, we show a substantial increase in Raldh1+/Raldh2+ PSCs and Raldh1+ activated macrophages in the lesion core. We find that RA levels are significantly elevated in the ischemic hemisphere and induce signaling in astrocytes and neurons in the peri-infarct region.. This study highlights a dual role for activated, non-neural cells where PSCs deposit fibrotic ECM proteins and, along with macrophages, act as a potentially important source of RA, a potent signaling molecule that could influence recovery events in a neuroprotective fashion following brain injury.

Topics: Animals; Animals, Newborn; Brain; Collagen Type I; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Immunohistochemistry; Infarction, Middle Cerebral Artery; Male; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Transgenic; Pericytes; Stroke; Stromal Cells; Tretinoin

Proteins involved in DNA double-strand break (DSB) repair localize within the promyelocytic leukemia nuclear bodies (PML-NBs), whose disruption is at the root of the acute promyelocytic leukemia (APL) pathogenesis. All-trans-retinoic acid (RA) treatment induces PML-RARα degradation, restores PML-NB functions, and causes terminal cell differentiation of APL blasts. However, the precise role of the APL-associated PML-RARα oncoprotein and PML-NB integrity in the DSB response in APL leukemogenesis and tumor suppression is still lacking. Primary leukemia blasts isolated from APL patients showed high phosphorylation levels of H2AX (γ-H2AX), an initial DSBs sensor. By addressing the consequences of ionizing radiation (IR)-induced DSB response in primary APL blasts and RA-responsive and -resistant myeloid cell lines carrying endogenous or ectopically expressed PML-RARα, before and after treatment with RA, we found that the disruption of PML-NBs is associated with delayed DSB response, as revealed by the impaired kinetic of disappearance of γ-H2AX and 53BP1 foci and activation of ATM and of its substrates H2AX, NBN, and CHK2. The disruption of PML-NB integrity by PML-RARα also affects the IR-induced DSB response in a preleukemic mouse model of APL in vivo. We propose the oncoprotein-dependent PML-NB disruption and DDR impairment as relevant early events in APL tumorigenesis.

Topics: Animals; Ataxia Telangiectasia Mutated Proteins; Cell Cycle Proteins; Cell Nucleus; Checkpoint Kinase 2; Disease Models, Animal; DNA; DNA Breaks, Double-Stranded; Gamma Rays; Gene Expression Regulation, Leukemic; Granulocyte Precursor Cells; Histones; Humans; Leukemia, Promyelocytic, Acute; Mice; Nuclear Proteins; Oncogene Proteins, Fusion; Signal Transduction; Tretinoin; Tumor Suppressor p53-Binding Protein 1

Antiretroviral drug therapy (ART) effectively suppresses replication of both the immunodeficiency viruses, human (HIV) and simian (SIV); however, virus rebounds soon after ART is withdrawn. SIV-infected monkeys were treated with a 90-day course of ART initiated at 5 weeks post infection followed at 9 weeks post infection by infusions of a primatized monoclonal antibody against the α

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes; Combined Modality Therapy; Cytokines; Disease Models, Animal; Female; Gastrointestinal Tract; Immunization, Passive; Infusions, Intravenous; Integrin alpha4; Integrin beta Chains; Killer Cells, Natural; Macaca mulatta; Male; Membrane Glycoproteins; Simian Acquired Immunodeficiency Syndrome; Simian Immunodeficiency Virus; T-Lymphocyte Subsets; Tretinoin; Viral Envelope Proteins; Viral Load; Viremia

To study the association between the expression of H3K27me3 and ACat2 (a folate metabolic protein), in order to elucidate the protective mechanism of folic acid (FA) in neural tube defects (NTDs).. Eighteen female SD rats were randomly divided into normal, NTD and FA group. NTD group was induced by all-trans retinoic acid (ATRA) at E10d. FA group was fed with FA supplementation since 2 weeks before pregnancy, followed by ATRA induction. At E15d, FA level in the embryonic neural tube was determined by ELISA. Neural stem cells (NSCs) were isolated. Cell proliferation was compared by CCK-8 assay. The differentiation potency was assessed by immunocytochemical staining. H3K27me3 expression was measured by immunofluorescence method and Western blot. ACat2 mRNA expression was detected by qRT-PCR.. Cultured NSCs formed numerous Nestin-positive neurospheres. After 5 days, they differentiated into NSE-positive neurons and GFAP-positive astrocytes. When compared with controls, the FA level in NTD group was significantly lower, the ability of cell proliferation and differentiation was significantly reduced, H3K27me3 expression was increased, and ACat2 mRNA expression was decreased (P <0.05). The intervention of FA notably reversed these changes (P <0.05). H3K27me3 expression was negatively correlated with the FA level (rs = -0.908, P <0.01) and ACat2 level (rs = -0.879, P <0.01) in the neural tube.. The increased H3K27me3 expression might cause a disorder of folate metabolic pathway by silencing ACat2 expression, leading to reduced proliferation and differentiation of NSCs, and ultimately the occurrence of NTD. FA supplementation may reverse this process.

Topics: Acetyl-CoA C-Acetyltransferase; Animals; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Epigenesis, Genetic; Female; Folic Acid; Gene Expression Regulation; Gene Silencing; Histones; Male; Neural Tube Defects; Rats; Rats, Sprague-Dawley; Tretinoin

The ectonucleotidases CD39 and CD73 sequentially degrade the extracellular ATP pool and release immunosuppressive adenosine, thereby regulating inflammatory responses. This control is likely to be critical in the gastrointestinal tract where high levels of ATP are released in particular by commensal bacteria. The aim of this study was therefore to evaluate the involvement of the adenosinergic regulation in the intestine of mice in steady-state conditions and on acute infection with Toxoplasma gondii. We show that both conventional (Tconv) and regulatory (Treg) CD4(+) T lymphocytes express CD39 and CD73 in the intestine of naive mice. CD73 expression was downregulated during acute infection with T. gondii, leading to impaired capacity to produce adenosine. Interestingly, the expression of adenosine receptors was maintained and treatment with receptor agonists limited immunopathology and dysbiosis, suggesting that the activation of adenosine receptors may constitute an efficient approach to control intestinal inflammation associated with decreased ectonucleotidase expression.

Topics: 5'-Nucleotidase; Adenosine; Animals; Antigens, CD; Apyrase; Disease Models, Animal; Gene Expression; Gene Expression Regulation; Intestinal Diseases; Mice; Mice, Knockout; Receptor, Adenosine A2A; Receptor, Adenosine A2B; T-Lymphocyte Subsets; Toxoplasma; Transforming Growth Factor beta; Tretinoin

A skin disease, like acne, is very common and normally happens to everyone at least once in their lifetime. The structure of the stratum corneum is often compared with a brick wall, with corneocytes surrounded by the mortar of the intercellular lipid lamellae. One of the best options for successful drug delivery to the affected area of skin is the use of elastic vesicles (niosomes) which can be transported through the skin through channel-like structures. In this study, a combination of tretinoin (keratolytic agent) and benzoyl peroxide (BPO) (a potent antibacterial) was given by using niosomes as promising carriers for the effective treatment of acne by acting on a pathogenic site. In this section, niosomal gel formulation encapsulated drugs have been evaluated for in vitro, ex vivo, and in vivo, for their predetermined characteristics; and finally the stability of the niosome gel was tested at different temperature conditions for understanding of the storage conditions required for maintaining the quality of formulation attributes. The prepared niosome was found to be in the range of 531 nm with a zeta potential of -43 mV; the entrapment efficiencies of tretinoin (TRA) and BPO niosomes were found to be 96.25%±0.56% and 98.75%±1.25%, respectively. The permeated amount of TRA and BPO from the niosomal gel after 24 hours was calculated as 6.25±0.14 μg/cm(2) and 5.04±0.014 μg/cm(2), respectively. A comparative drug retention study in Wistar rat skin using cream, an alcoholic solution, and a niosomal gel showed 11.54 μg, 2.68 μg, and 15.54 μg amounts of TRA and 68.85 μg, 59.98 μg, and 143.78 μg amounts of BPO were retained in the layers of skin, respectively. In vivo studies of the niosomal gel and antiacne cream of TRA and BPO showed that the niosomal gel was more efficacious than the antiacne cream because niosomal gels with a 4.16-fold lower dose of BPO provided the same therapeutic index at targeted sites in comparison to the antiacne cream.

Topics: Acne Vulgaris; Animals; Anti-Bacterial Agents; Benzoyl Peroxide; Disease Models, Animal; Drug Delivery Systems; Drug Resistance, Bacterial; Gels; Liposomes; Microbial Sensitivity Tests; Microscopy, Electron, Transmission; Particle Size; Rabbits; Rats; Rats, Wistar; Skin; Staphylococcus epidermidis; Tretinoin

Clinical reports suggest a potential link between excess retinoids and development of depression. Corticotropin-releasing factor (CRF) produced in the hypothalamic paraventricular nucleus (PVN) is considered the central driver of the hypothalamic-pituitary-adrenal (HPA) axis and plays a key role in the pathogenesis of depression. Although we had shown that chronic all-trans retinoic acid (ATRA) administration induced hypothalamic CRF over-expression and hyperactivity of HPA axis in rats, further insight into how ATRA modulate CRF expression is lacking. The activity of CRF neurons is under close control of vasopressinergic system and three-paired receptors (corticosteroid receptors, sex hormone receptors and CRF receptors). Here we show that ATRA-induced CRF over-expression is accompanied by arginine-vasopressin (AVP) up-regulation and apparent gene expression disturbances of CRF-controlling receptors. ATRA was applied to rats by daily intraperitoneal injection for 6 weeks. Chronic ATRA treatment induced significantly increased expression of CRF and AVP in the PVN. Moreover, the transcript levels of CRF receptor 1 (CRFR1), estrogen receptor-β (ERβ) and mineralocorticoid receptor (MR), three genes involved in the activation of CRF neurons, were significantly increased in the hypothalamus, and the expression ratio of GRα/MR was markedly decreased. Correlation analysis indicated that the alteration of multiple CRF-controlling receptors is highly correlated with depression-related behaviors of rats in the forced swimming test. These findings support that in addition to the 'classic' retinoic acid receptor α-mediated transcriptional control of CRF expression, disruption in CRF-modulating systems constitutes a novel pathway that underlies ATRA-induced HPA axis hyperactivity in vivo.

Topics: Animals; Arginine Vasopressin; Corticosterone; Corticotropin-Releasing Hormone; Depression; Disease Models, Animal; Estrogen Receptor beta; Gene Expression; Hypothalamus; Male; Motor Activity; Neurons; Paraventricular Hypothalamic Nucleus; Rats; Rats, Sprague-Dawley; Receptors, Corticotropin-Releasing Hormone; Receptors, Mineralocorticoid; RNA, Messenger; Tretinoin

The all trans retinoic acid (ATRA) is found to have a promising regulatory effect on immune system and inflammatory responses in experimental research. The purpose of this study was to investigate whether this therapeutic efficiency of ATRA could be enhanced by encapsulating into a liposome formulation composed of Distearoyl-L-phosphatidylcholine (DSPC) and cholesterol utilizing a well-established mice model. The humoral antibody titer (HA), delayed-type hypersensitivity (DTH), bone marrow cellularity, hematology, and levels of α- esterase-positive cells, were taken as parameters to assess the level of immunomodulation in the sheep red blood cells (SRBC) immunized and challenged BALB/c mice. The anti-inflammatory effect of encapsulated ATRA was evaluated by the size changes in the induced inflammation edema in the mice paw as well as its histopathology. The results showed a significant immunostimulatory effect for both the free and encapsulated ATRA as indicated by the increase in the levels of total leukocyte, bone marrow and α-esterase positive cells and decreased Hb level respectively. We have also observed an enhanced specific antibody hemagglutinin titre value and the DTH response developed in response to SRBC challenge in these treatments. Both the immunostimulatory as well as inflammation reducing property were significantly higher in encapsulated ATRA treated group of mice over that of in free ATRA treated group of mice. Based on these results, we conclude that the encapsulated ATRA has a higher potency over free ATRA in its immunomodulatory activity and also has a significant impact on reducing inflammation in BALB/c mice model.

Topics: Animals; Bone Marrow; Cholesterol; Disease Models, Animal; Edema; Esterases; Immunomodulation; Inflammation; Leukocytes; Liposomes; Male; Mice; Mice, Inbred BALB C; Phosphatidylcholines; Sheep; Tretinoin

Roles of all-trans-retinoic acid (tRA), a metabolite of vitamin A (VA), in both tolerogenic and immunogenic responses are documented. However, how tRA affects the development of systemic autoimmunity is poorly understood. Here we demonstrate that tRA have paradoxical effects on the development of autoimmune lupus in the MRL/lpr mouse model. We administered, orally, tRA or VA mixed with 10% of tRA (referred to as VARA) to female mice starting from 6 weeks of age. At this age, the mice do not exhibit overt clinical signs of lupus. However, the immunogenic environment preceding disease onset has been established as evidenced by an increase of total IgM/IgG in the plasma and expansion of lymphocytes and dendritic cells in secondary lymphoid organs. After 8 weeks of tRA, but not VARA treatment, significantly higher pathological scores in the skin, brain and lung were observed. These were accompanied by a marked increase in B-cell responses that included autoantibody production and enhanced expression of plasma cell-promoting cytokines. Paradoxically, the number of lymphocytes in the mesenteric lymph node decreased with tRA that led to significantly reduced lymphadenopathy. In addition, tRA differentially affected renal pathology, increasing leukocyte infiltration of renal tubulointerstitium while restoring the size of glomeruli in the kidney cortex. In contrast, minimal induction of inflammation with tRA in the absence of an immunogenic environment in the control mice was observed. Altogether, our results suggest that under a predisposed immunogenic environment in autoimmune lupus, tRA may decrease inflammation in some organs while generating more severe disease in others.

Topics: Age Factors; Animals; Autoimmunity; Brain; Disease Models, Animal; Female; Inflammation Mediators; Kidney; Leukocytes; Lung; Lupus Erythematosus, Systemic; Lymphatic Diseases; Mice; Mice, Inbred MRL lpr; Skin; Tretinoin

The contribution of vitamin A to immune health has been well established. However, recent evidence indicates that its active metabolite, retinoic acid (RA), has the ability to promote both tolerogenic and inflammatory responses. While the outcome of RA-mediated immunity is dependent upon the immunological status of the tissue, the contribution of specific innate signals influencing this response have yet to be delineated. Here, we found that treatment with RA can dampen inflammation during intestinal injury. Importantly, we report a novel and unexpected requirement for TLR2 in RA-mediated suppression. Our data demonstrate that RA treatment enhances TLR2-dependent IL-10 production from T cells and this, in turn, potentiates T regulatory cell (TREG) generation without the need for activation of antigen presenting cells. These data also suggest that combinatorial therapy using RA and TLR2 ligands may be advantageous in the design of therapies to treat autoimmune or inflammatory disease.

Topics: Animals; Biomarkers; CD4-Positive T-Lymphocytes; Colitis; Cytokines; Dendritic Cells; Disease Models, Animal; Immune Tolerance; Immunophenotyping; Inflammation Mediators; Intestinal Mucosa; Lymphocyte Activation; Mice; Signal Transduction; T-Lymphocyte Subsets; Toll-Like Receptor 2; Tretinoin; Vitamin A

Forty-two cell lines recapitulating mammary carcinoma heterogeneity were profiled for all-trans retinoic acid (ATRA) sensitivity. Luminal and ER(+) (estrogen-receptor-positive) cell lines are generally sensitive to ATRA, while refractoriness/low sensitivity is associated with a Basal phenotype and HER2 positivity. Indeed, only 2 Basal cell lines (MDA-MB157 and HCC-1599) are highly sensitive to the retinoid. Sensitivity of HCC-1599 cells is confirmed in xenotransplanted mice. Short-term tissue-slice cultures of surgical samples validate the cell-line results and support the concept that a high proportion of Luminal/ER(+) carcinomas are ATRA sensitive, while triple-negative (Basal) and HER2-positive tumors tend to be retinoid resistant. Pathway-oriented analysis of the constitutive gene-expression profiles in the cell lines identifies RARα as the member of the retinoid pathway directly associated with a Luminal phenotype, estrogen positivity and ATRA sensitivity. RARα3 is the major transcript in ATRA-sensitive cells and tumors. Studies in selected cell lines with agonists/antagonists confirm that RARα is the principal mediator of ATRA responsiveness. RARα over-expression sensitizes retinoid-resistant MDA-MB453 cells to ATRA anti-proliferative action. Conversely, silencing of RARα in retinoid-sensitive SKBR3 cells abrogates ATRA responsiveness. All this is paralleled by similar effects on ATRA-dependent inhibition of cell motility, indicating that RARα may mediate also ATRA anti-metastatic effects. We define gene sets of predictive potential which are associated with ATRA sensitivity in breast cancer cell lines and validate them in short-term tissue cultures of Luminal/ER(+) and triple-negative tumors. In these last models, we determine the perturbations in the transcriptomic profiles afforded by ATRA. The study provides fundamental information for the development of retinoid-based therapeutic strategies aimed at the stratified treatment of breast cancer subtypes.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Line, Tumor; Disease Models, Animal; Female; Gene Expression; Gene Expression Profiling; Gene Silencing; Humans; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Transplantation, Heterologous; Tretinoin

Increased levels of fetal hemoglobin are associated with decreased symptoms and increased lifespan in patients with sickle cell disease (SCD). Hydroxyurea, the only drug currently approved for SCD, is not effective in a large fraction of patients, and therefore, new agents are urgently needed. Recently it was found that lysine demethylase 1, an enzyme that removes monomethyl and dimethyl residues from the lysine 4 residue of histone H3, is a repressor of γ-globin gene expression. In this article, we have compared the ability of tranylcypromine (TCP) and a more potent TCP derivative, RN-1, to increase γ-globin expression in cultured baboon erythroid progenitor cells and in the SCD mouse model. The results indicate that the ability of RN-1 to induce F cells and γ-globin mRNA in SCD mice is similar to that of decitabine, the most powerful fetal hemoglobin-inducing drug known, and greater than that of either TCP or hydroxyurea. We conclude that RN-1 and other lysine demethylase 1 inhibitors may be promising new γ-globin-inducing agents for the treatment of SCD that warrant further studies in other preclinical models, such as nonhuman primates.

Topics: Anemia, Sickle Cell; Animals; Disease Models, Animal; Drug Evaluation, Preclinical; Enzyme Inhibitors; Erythroid Precursor Cells; Erythropoiesis; Fetal Hemoglobin; gamma-Globins; Gene Expression Regulation; Hematopoietic Stem Cells; Histone Demethylases; Histones; Humans; Hydroxyurea; Methylation; Mice; Mice, Transgenic; Papio; Protein Processing, Post-Translational; Reticulocytes; Transgenes; Tranylcypromine; Tretinoin; U937 Cells

Retinoic acid-arsenic trioxide (ATRA-ATO) combination therapy is the current standard of care for patients with acute promyelocytic leukemia (APL) carrying the oncogenic fusion protein PML-RARα. Despite the high cure rates obtained with this drug combination, resistance to arsenic is recently emerging. Moreover, patients with APL carrying the PLZF-RARα fusion protein are partially resistant to ATRA treatment. Hypoxia-inducible factor-1α (HIF-1α) activation has been recently reported in APL, and EZN-2208 (PEG-SN38) is a compound with HIF-1α inhibitory function currently tested in clinical trials. This study investigates the effect of EZN-2208 in different preclinical APL models, either alone or in combination with ATRA.. Efficacy of EZN-2208 in APL was measured in vitro by assessing expression of HIF-1α target genes, cell migration, clonogenicity, and differentiation, vis a vis the cytotoxic and cytostatic effects of this compound. In vivo, EZN-2208 was used in mouse models of APL driven by PML-RARα or PLZF-RARα, either alone or in combination with ATRA.. Treatment of APL cell lines with noncytotoxic doses of EZN-2208 causes dose-dependent downregulation of HIF-1α bona fide target genes and affects cell migration and clonogenicity in methylcellulose. In vivo, EZN-2208 impairs leukemia progression and prolongs mice survival in APL mouse models. More importantly, when used in combination with ATRA, EZN-2208 synergizes in debulking leukemia and eradicating leukemia-initiating cells.. Our preclinical data suggest that the combination ATRA-EZN-2208 may be tested to treat patients with APL who develop resistance to ATO or patients carrying the PLZF-RARα fusion protein.

Topics: Animals; Arsenic Trioxide; Arsenicals; Camptothecin; Cell Differentiation; Cell Movement; Disease Models, Animal; Drug Resistance, Neoplasm; Drug Synergism; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Leukemia, Promyelocytic, Acute; Mice; Mutation; Neoplasm Proteins; Oncogene Proteins, Fusion; Oxides; Polyethylene Glycols; Tretinoin

Daratumumab is an anti-CD38 monoclonal antibody with lytic activity against multiple myeloma (MM) cells, including ADCC (antibody-dependent cellular cytotoxicity) and CDC (complement-dependent cytotoxicity). Owing to a marked heterogeneity of response to daratumumab therapy in MM, we investigated determinants of the sensitivity of MM cells toward daratumumab-mediated ADCC and CDC. In bone marrow samples from 144 MM patients, we observed no difference in daratumumab-mediated lysis between newly diagnosed or relapsed/refractory patients. However, we discovered, next to an expected effect of effector (natural killer cells/monocytes) to target (MM cells) ratio on ADCC, a significant association between CD38 expression and daratumumab-mediated ADCC (127 patients), as well as CDC (56 patients). Similarly, experiments with isogenic MM cell lines expressing different levels of CD38 revealed that the level of CD38 expression is an important determinant of daratumumab-mediated ADCC and CDC. Importantly, all-trans retinoic acid (ATRA) increased CD38 expression levels but also reduced expression of the complement-inhibitory proteins CD55 and CD59 in both cell lines and primary MM samples. This resulted in a significant enhancement of the activity of daratumumab in vitro and in a humanized MM mouse model as well. Our results provide the preclinical rationale for further evaluation of daratumumab combined with ATRA in MM patients.

Topics: ADP-ribosyl Cyclase 1; Adult; Aged; Aged, 80 and over; Animals; Antibodies, Monoclonal; Antibody-Dependent Cell Cytotoxicity; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bone Marrow; Cell Proliferation; Cytotoxicity, Immunologic; Disease Models, Animal; DNA-Binding Proteins; Drug Resistance, Neoplasm; Drug Synergism; Female; Flow Cytometry; Humans; Male; Membrane Glycoproteins; Mice; Middle Aged; Multiple Myeloma; Neoplasm Recurrence, Local; Salvage Therapy; Tretinoin; Tumor Cells, Cultured

Breast cancer is the leading cause of death among women worldwide. The exact role of luminal epithelial (LEP) and myoephitelial (MEP) cells in breast cancer development is as yet unclear, as also how retinoids may affect their behaviour. Here, we set out to evaluate whether retinoids may differentially regulate cell type-specific processes associated with breast cancer development using the bi-cellular LM38-LP murine mammary adenocarcinoma cell line as a model.. The bi-cellular LM38-LP murine mammary cell line was used as a model throughout all experiments. LEP and MEP subpopulations were separated using inmunobeads, and the expression of genes known to be involved in epithelial to mysenchymal transition (EMT) was assessed by qPCR after all-trans retinoic acid (ATRA) treatment. In vitro invasive capacities of LM38-LP cells were evaluated using 3D Matrigel cultures in conjunction with confocal microscopy. Also, in vitro proliferation, senescence and apoptosis characteristics were evaluated in the LEP and MEP subpopulations after ATRA treatment, as well as the effects of ATRA treatment on the clonogenic, adhesive and invasive capacities of these cells. Mammosphere assays were performed to detect stem cell subpopulations. Finally, the orthotopic growth and metastatic abilities of LM38-LP monolayer and mammosphere-derived cells were evaluated in vivo.. We found that ATRA treatment modulates a set of genes related to EMT, resulting in distinct gene expression signatures for the LEP or MEP subpopulations. We found that the MEP subpopulation responds to ATRA by increasing its adhesion to extracellular matrix (ECM) components and by reducing its invasive capacity. We also found that ATRA induces apoptosis in LEP cells, whereas the MEP compartment responded with senescence. In addition, we found that ATRA treatment results in smaller and more organized LM38-LP colonies in Matrigel. Finally, we identified a third subpopulation within the LM38-LP cell line with stem/progenitor cell characteristics, exhibiting a partial resistance to ATRA.. Our results show that the luminal epithelial (LEP) and myoephitelial (MEP) mammary LM38-P subpopulations respond differently to ATRA, i.e., the LEP subpopulation responds with increased cell cycle arrest and apoptosis and the MEP subpopulation responds with increased senescence and adhesion, thereby decreasing its invasive capacity. Finally, we identified a third subpopulation with stem/progenitor cell characteristics within the LM38-LP mammary adenocarcinoma cell line, which appears to be non-responsive to ATRA.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Breast Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Models, Animal; Epithelial Cells; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Humans; Mammary Neoplasms, Animal; Mice, Inbred BALB C; Microscopy, Fluorescence; Models, Biological; Receptors, Retinoic Acid; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin; Tumor Burden

The intact blood-brain barrier (BBB) is essential in maintaining a stabilized milieu for synaptic and neuronal functions. Disruptions of the BBB have been observed following ischemia and reperfusion, both in patients and in animal models. Retinoic acid (RA), which plays crucial roles during vertebrate organogenesis, has been reported to participate in BBB development. However, it remains unclear whether RA could prevent BBB disruption in ischemic stroke. In this study, we determined that the injection of RA for 4 consecutive days resulted in increases in zonula occludens-1 (ZO-1) and vascular endothelial cadherin (VE-cadherin) expression, which are crucial components of the BBB structure. We demonstrated that RA pretreatment could alleviate the ischemic stroke-induced enlargement of vascular permeability, which is related to the up-regulated expression of ZO-1 and VE-cadherin proteins in rat models of middle cerebral artery occlusion (MCAO). Our findings further corroborated that the RA protective effect on BBB is dependent on RA receptor α in vitro oxygen-glucose deprivation (OGD) treatment. Significantly, RA administration immediately after MCAO reduced tissue plasminogen activator (tPA)-induced intracerebral hemorrhage (ICH) and ameliorated neurological deficits 24h after ischemic stroke. Taken together, our results suggest that RA may become a new therapeutic approach to prevent BBB dysfunction and tPA-induced ICH in ischemic stroke.

Topics: Animals; Antigens, CD; Blood-Brain Barrier; Cadherins; Capillary Permeability; Cell Line; Disease Models, Animal; Injections, Intraperitoneal; Male; Rats; Rats, Sprague-Dawley; Stroke; Tretinoin; Zonula Occludens-1 Protein

Insulin resistance and neuroinflammation have emerged as two likely key contributors in the pathogenesis of Alzheimer disease (AD), especially in those sporadic AD cases compromised by diabetes or cardiovascular disease. Amyloid-β (Aβ) deposition and its associated inflammatory response are hallmarks in sporadic AD brains. Elevated expression and activity of β-secretase 1 (BACE1), the rate-limiting enzyme responsible for the β-cleavage of amyloid precursor proteins to Aβ peptides, are also observed in sporadic AD brains. Previous studies have suggested that there is therapeutic potential for retinoic acid in treating neurodegeneration based on decreased Aβ. Here we discovered that BACE1 expression is elevated in the brains of both Tg2576 transgenic mice and mice on high fat diets. These conditions are associated with a neuroinflammatory response. We found that administration of all-trans-retinoic acid (atRA) down-regulated the expression of BACE1 in the brains of Tg2576 mice and in mice fed a high fat diet. Moreover, in LPS-treated mice and cultured neurons, BACE1 expression was repressed by the addition of atRA, correlating with the anti-inflammatory efficacy of atRA. Mutations of the NFκB binding site in BACE1 promoter abolished the suppressive effect of atRA. Furthermore, atRA disrupted LPS-induced nuclear translocation of NFκB and its binding to BACE1 promoter as well as promoting the recruitment of the corepressor NCoR. Our findings indicate that atRA represses BACE1 gene expression under inflammatory conditions via the modulation of NFκB signaling.

Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Animals; Aspartic Acid Endopeptidases; Brain; Dietary Fats; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Mice; Mice, Transgenic; NF-kappa B; Signal Transduction; Tretinoin

Active suppression induced by regulatory T (Treg) cells is reported to be one of the mechanisms involved in oral tolerance. All-trans retinoic acid (ATRA) has been reported to affect Treg cell differentiation. The present study examined the effects of ATRA on the induction of oral tolerance in a murine model of bronchial asthma.. BALB/c mice were sensitized to and challenged with ovalbumin (OVA) through feeding followed by OVA challenges. In some study groups ATRA was orally administered concomitantly with OVA feeding either in the presence or absence of the retinoic acid receptor antagonist LE135. Lung CD4+ T cells were isolated from mice exposed to ATRA and/or OVA, and transferred to control mice. Airway hyperresponsiveness (AHR), cell counts and cytokine levels in bronchoalveolar lavage (BAL) fluid, and lung histology were assessed.. Concomitant administration of ATRA with OVA ameliorated AHR, airway eosinophilia, elevation of cytokines in BAL fluid and goblet cell metaplasia. The proportion of Treg cells in the lungs was increased in mice treated with OVA and ATRA, as compared to those treated with OVA only. Transfer of lung CD4+ T cells from mice treated with OVA and ATRA induced suppression of AHR and airway inflammation. LE135 completely reversed the effects of ATRA on AHR, airway allergic inflammation and the number of Treg cells in the lungs.. These data suggested that oral administration of ATRA with OVA had the potential to enhance oral tolerance in this murine model of bronchial asthma. These effects were mediated, at least in part, by Treg cell expansion.

Topics: Adoptive Transfer; Airway Remodeling; Animals; Asthma; Bronchoalveolar Lavage Fluid; Dibenzazepines; Disease Models, Animal; Female; Forkhead Transcription Factors; Immune Tolerance; Immunophenotyping; Lung; Mice; Ovalbumin; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Tretinoin

Psoriasis is a chronic inflammatory skin disease and topical therapy remains a key role for treatment. The aim of this study is to evaluate the influence of psoriasis-like lesions on the cutaneous permeation of anti-psoriatic drugs.. We first set up imiquimod-induced dermatitis in mice that closely resembles human psoriasis lesions. The development of the lesions is based on the IL-23/IL17A axis for phenotypical and histological characteristics. Four drugs, 5-aminolevulinic acid (ALA), tacrolimus, calcipotriol, and retinoic acid, were used to evaluate percutaneous absorption.. The most hydrophilic molecule, ALA, revealed the greatest enhancement on skin absorption after imiquimod treatment. Imiquimod increased the skin deposition and flux of ALA by 5.6 to 14.4-fold, respectively, compared to normal skin. The follicular accumulation of ALA was also increased 3.8-fold. The extremely lipophilic drug retinoic acid showed a 1.7- and 3.8-fold increase in skin deposition and flux, respectively. Tacrolimus flux was enhanced from 2 to 21 μg/cm2/h by imiquimod intervention. However, imiquimod did not promote skin deposition of this macrolide. The lipophilicity, but not the molecular size, dominated drug permeation enhancement by psoriatic lesions. The in vivo percutaneous absorption of ALA and rhodamine B examined by confocal microscopy confirmed the deficient resistance of epidermal barrier for facilitating cutaneous delivery of drugs via psoriasis-like skin.. We established the topical delivery profiles of anti-psoriatic drugs via imiquimod-treated psoriasis-like skin.

Topics: Aminolevulinic Acid; Aminoquinolines; Animals; Cytokines; Disease Models, Animal; Female; Imiquimod; Mice; Psoriasis; Skin; Skin Absorption; Tacrolimus; Tretinoin

Skin cancer burden is significant as treatment costs have skyrocketed to $8.1 million annually and some forms metastasize, such as cutaneous squamous cell carcinoma (cSCC) and melanoma. cSCC is caused by altered growth factor signaling induced by chemical carcinogens, ultraviolet light (UV) exposure, and infections with papillomaviruses (PVs). One of the few options for preventing cSCC in high-risk patients is oral retinoids. While much is understood about retinoid treatments and metabolism in mouse models of chemically and UV exposure induced cSCC, little is known about the role of retinoids in PV-induced cSCC. To better understand how retinoid metabolism is altered in cSCC, we examined the expression of this pathway in the newly discovered mouse papillomavirus (MmuPV1), which produces trichoblastomas in dorsal skin but not cSCC. We found significant increases in a rate-limiting enzyme involved in retinoic acid synthesis and retinoic acid binding proteins, suggestive of increased RA synthesis, in MmuPV1-induced tumors in B6.Cg-Foxn1(nu)/J mice. Similar increases in these proteins were seen after acute UVB exposure in Crl:SKH1-Hr(hr) mice and in regressing pre-cancerous lesions in a chemically-induced mouse model, suggesting a common mechanism in limiting the progression of papillomas to full blown cSCC.

Topics: Animals; Carcinoma, Squamous Cell; Disease Models, Animal; Female; Immunohistochemistry; Mice; Oligonucleotide Array Sequence Analysis; Papillomaviridae; Papillomavirus Infections; Skin Neoplasms; Transcriptome; Tretinoin

To investigate the effects of all-trans retinoic acid (atRA) on the function of bone morphogenetic protein receptor 2 (BMPR2) expression in embryonic palate.. Cleft palate mice model was established by atRA. On gestation day (GD) 15 and GD 17, the pregnant mice were killed to obtain the embryos from the uteri. The embryonic palates were stained with hematoxylin-eosin, and the remaining sections were used for the immunohistochemistry of BMPR2 detection. Reverse transcription-polymerase chain reaction was performed to detect the expression levels of Bmpr2 mRNA.. In the atRA-treated group, short extensions and failure to fuse with each other were observed. The positive expression of BMPR2 was detected in developing palatal process from GD 15 to GD 17 in the control group. Compared with those of the control group, BMPR2 protein and Bmpr2 mRNA decreased in the atRA-treated group (P<0.05).. The treatment of pregnant mice with retinoic acid produces small palatal shelves in their fetuses and down-regulates BMPR2 expressions.

Topics: Animals; Bone Morphogenetic Protein 2; Cleft Palate; Disease Models, Animal; Down-Regulation; Female; Mice; Pregnancy; RNA, Messenger; Tretinoin

The treatment of acute respiratory distress syndrome (ARDS), most commonly seen during the organ dysfunction remains unsatisfied. Presently, the stem/progenitor cell-based endogenous repair has been aroused attention enormously. This report investigated the effects of retinoic acid (RA) plus simvastatin (SS) with respect to dynamics of lung repair cells as well as to elucidate the underlying mechanism.. The experimental Sprague-Dawley rats were divided randomly into normal control (control), sham operated (sham), ARDS, ARDS +  vehicle and ARDS + RA + SS groups. ARDS was reproduced through hemorrhagic shock/resuscitation (shock) and subsequent intratracheal LPS (4.5 mg/kg, Escherichia coli serotype O55: B5) injection. The rats were treated by intragastric administration of RA (2 mg/kg/day) and SS (2 mg/kg/day) for 5 days in the ARDS + RA + SS group. Seven days after the first RA-SS injection, a right lower lobe of lung was sampled for histological analysis concerning systemic uniform random sampling method. Immunohistochemistry of inflation-fixed lungs for alveolar type 1 (AT1), alveolar type 2 (AT2) and Clara cells was measured by AQP5, Pro-SPC and CCSP staining respectively. The alveolar cell proliferation and apoptosis were analyzed with Ki67 staining and terminal deoxylnucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) method. Meanwhile, the alveolar cell numerical and surface density (alveolar cells, AT1, AT2, Clara, proliferating and apoptotic cells) were evaluated by stereology.. RA-SS compound exerted anti-inflammatory and pro-repairing effects on respiratory tracts in ARDS induced by hemorrhagic-endotoxin shock. The numerical density and surface density of alveolar cells, AT1 cell fraction, and numerical density of AT2 and Clara cells were significantly increased after treatment with RA-SS compound in ARDS. Concurrently, the Ki67+ alveolar cells were obviously increased while the TUNEL+ alveolar cells were reduced, which was correlated with the attenuation of inflammatory injury and functional repair in injured lung tissues.. Our data convincingly indicated that the prophylactic and therapeutic treatment of RA plus SS had obvious beneficial effect on the remodeling/regeneration of injured pulmonary tissues, suggesting that the underlying mechanisms are related to the re-balance between regeneration and apoptosis in lung stem/progenitor cells.

Topics: Acute Lung Injury; Alveolar Epithelial Cells; Animals; Apoptosis; Cell Proliferation; Disease Models, Animal; Drug Therapy, Combination; Lung; Rats, Sprague-Dawley; Regeneration; Simvastatin; Stem Cells; Tretinoin

The effect of all-trans retinoic acid (ATRA) on the expression of α-smooth muscle actin (α-SMA) in rats with pulmonary arterial hypertension (PAH) was studied, and the mechanism of the effect of ATRA on PAH was proposed. Thirty male SD rats were randomly divided into normal control, monocrotaline (MCT) model, and ATRA [30 mg/(kg.day)]intervention groups (N = 10 each). The mean pulmonary arterial pressure was recorded. Right ventricular hypertrophy index (RVHI) was calculated (weight of right ventricle: total weight of left ventricle and interventricular septum). The percentages of wall thickness of pulmonary arteriole (WT) to external diameter of artery (WT%) and vascular wall area (WA) to total vascular area (WA%) were determined. Real-time fluorescence-based quantitative PCR and western blot analyses were employed to detect the α-SMA mRNA and protein expressions. The mean pulmonary arterial pressure, RVHI, WT%, and WA% were all obviously higher in the model group than in the control and intervention groups. The values of these indicators in the intervention group were also higher than those in the control group (P < 0.01). The mRNA and protein expression levels of α-SMA were significantly higher in the lung tissue of model rats than those in the control and intervention groups. However, the intervention group showed no statistically significant differences in α-SMA mRNA and protein expression levels compared to the control (P < 0.05). ATRA inhibited the α-SMA mRNA and protein expressionin the lung tissues of rats with MCT-induced PAH, and could be used to treat PAH.

Topics: Actins; Animals; Disease Models, Animal; Hypertension, Pulmonary; Lung; Male; Monocrotaline; Pulmonary Artery; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tretinoin

To study the role of autophagy and the relationship between retinoic acid receptor α (RARα) and autophagy in liver ischemia and reperfusion (IR) injury.. All-trans retinoic acid (ATRA) was administered to mice for two weeks before operation. Reverse transcription-polymerase chain reaction and Western blot were used to detect the expression levels of related factors. To demonstrate the role of RARα, LE540, a RARα inhibitor, was used to treat hepatocytes injured by H2O2 in vitro.. ATRA pretreatment noticeably diminished levels of serum alanine aminotransferase and aspartate aminotransferase as well as the degree of histopathological changes. Apoptosis was also inhibited, whereas autophagy was promoted. In vitro, RARα was inhibited by LE540, which resulted in decreased autophagy and increased apoptosis. Similarly, the expression of Foxo3a and p-Akt was downregulated, but Foxo1 expression was upregulated.. This research provides evidence that ATRA can protect the liver from IR injury by promoting autophagy, which is dependent on Foxo3/p-Akt/Foxo1 signaling.

Topics: Animals; Apoptosis; Autophagy; Cytoprotection; Dibenzazepines; Disease Models, Animal; Forkhead Box Protein O1; Forkhead Box Protein O3; Forkhead Transcription Factors; Hepatocytes; Hydrogen Peroxide; Liver; Liver Diseases; Male; Mice, Inbred C57BL; Oxidative Stress; Phosphorylation; Proto-Oncogene Proteins c-akt; Receptors, Retinoic Acid; Reperfusion Injury; Retinoic Acid Receptor alpha; Signal Transduction; Time Factors; Tretinoin

It has been found that nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2-ARE) signaling pathway plays a role in antioxidative response, anti-inflammatory response, and neuron-protection in intracerebral hemorrhage (ICH). The aim of this study is to explore mechanisms underlying the perifocal neuroprotective effect of the Nrf2-ARE signaling pathway after ICH.. There were a total of 90 rats with basal ganglia hemorrhage, which were randomly divided into the following four groups: ICH (Sprague-Dawley rats with autologous femoral arterial blood injection into the basal ganglia), sulforaphane (SFN) (SFN was intraperitoneally administered into rats), retinoic acid (RA) (RA was intraperitoneally administered into rats), and dimethyl sulfoxide (the rats were treated with dimethyl sulfoxide). We observed the neurological score of the rats in the different groups, and collected brain tissues for immunofluorescence, Western blot, and reverse transcription polymerase chain reaction to detect expression of Nrf2, heme oxygenase (HO-1), nuclear factor-κB (NF-κB), and tumor necrosis factor-α (TNF-α).. The results indicated that neurological dysfunction of rats was significantly improved in the SFN group, and the expressions of Nrf2 and HO-1 in tissues surrounding the hemorrhage were increased. Also, the level of NF-κB and TNF-α were reduced compared to the ICH group. The RA group exhibited more severe neurological dysfunction and lower levels of Nrf2 and HO-1 than the SFN and ICH groups. Compared to the ICH group, the NF-κB and TNF-α expression in the RA groups was increased. In conclusion, RA inhibits Nrf2 dissociation and translocation into nucleus, thereby suppressing the anti-inflammatory effect of Nrf2-ARE signaling pathway. The activation of Nrf2-ARE signaling pathway by SFN can elevate expression of antioxidant enzyme HO-1, reduce perifocal inflammatory response after ICH, and thus may play a neuroprotective role.. The results suggest that Nrf2-ARE signaling pathway may serve as a new target for treatment of perifocal inflammatory injury caused by ICH.

Topics: Animals; Antioxidant Response Elements; Blotting, Western; Cerebral Hemorrhage; Dimethyl Sulfoxide; Disease Models, Animal; Heme Oxygenase-1; Isothiocyanates; Male; Neuroprotection; NF-E2-Related Factor 2; NF-kappa B; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Sulfoxides; Tretinoin; Tumor Necrosis Factor-alpha

Previous studies indicate that the Nrf2-ARE signaling pathway plays a neruo-protective role in glia cell, however, the mechanism was also elusive. This study aims to explore the inhibitive function of all-trans-retinoic (ATRA) on Nrf2-ARE pathway in intracerebral hemorrhage (ICH), and investigate the mechanism. In this study, the femoral artery injection method was employed to establish ICH model. The model rats were randomly divided into four groups, including Sham group, ICH group, ATRA group and DMSO group. The neurological scores were evaluated for the four groups at different time points. Hematoxylin-Eosin staining was used to stain the CD11b positive glia cells. Double immunofluorescence staining method was utilized to observe the co-expression of HO-1, NF-κB, Nrf2 and TNF-α and CD11b marker in glia cells. Western blot assay was used to detect the Nrf2 protein (total and binding Nrf2), HO-1, NF-κB and TNF-α proteins in every group. The results indicated that neurologiclal scores were significantly decreased in ATRA group compared to ICH gorup (P < 0.05). The glia cells were significantly activated and accumulated in ICH rats. ATRA significantly decreased co-expression of Nrf2, HO-1 and CD11b, and increased co-expression of NF-κB, TNF-α and CD11b of glia cells. ATRA significantly decreased total Nrf2 expression and increased binding Nrf2 expression in ATRA group compared to ICH group (P < 0.05). ATRA decreased anti-oxygen protein Nrf2 and HO-1, and increases inflammatory factors NF-κB and TNF-α. In conclusion, the application of ATRA could inhibit the neuro-protective function effectively by blocking the Nrf2-ARE pathway in glia cells.

Topics: Animals; Blotting, Western; Carboxylic Ester Hydrolases; Cerebral Hemorrhage; Disease Models, Animal; Fluorescent Antibody Technique; Male; Neuroglia; NF-E2-Related Factor 2; Rats; Rats, Sprague-Dawley; Signal Transduction; Tretinoin

Topics: Adjuvants, Immunologic; Animals; Arsenic Trioxide; Arsenicals; Disease Models, Animal; DNA; Immunotherapy; Leukemia, Promyelocytic, Acute; Mice; Oxides; Tretinoin

Resistance of myeloma to lenalidomide is an emerging clinical problem, and though it has been associated in part with activation of Wnt/β-catenin signaling, the mediators of this phenotype remained undefined. Lenalidomide-resistant models were found to overexpress the hyaluronan (HA)-binding protein CD44, a downstream Wnt/β-catenin transcriptional target. Consistent with a role of CD44 in cell adhesion-mediated drug resistance (CAM-DR), lenalidomide-resistant myeloma cells were more adhesive to bone marrow stroma and HA-coated plates. Blockade of CD44 with monoclonal antibodies, free HA or CD44 knockdown reduced adhesion and sensitized to lenalidomide. Wnt/β-catenin suppression by FH535 enhanced the activity of lenalidomide, as did interleukin-6 neutralization with siltuximab. Notably, all-trans retinoic acid (ATRA) downregulated total β-catenin, cell-surface and total CD44, reduced adhesion of lenalidomide-resistant myeloma cells and enhanced the activity of lenalidomide in a lenalidomide-resistant in vivo murine xenograft model. Finally, ATRA sensitized primary myeloma samples from patients that had relapsed and/or refractory disease after lenalidomide therapy to this immunomodulatory agent ex vivo. Taken together, our findings support the hypotheses that CD44 and CAM-DR contribute to lenalidomide resistance in multiple myeloma, that CD44 should be evaluated as a putative biomarker of sensitivity to lenalidomide, and that ATRA or other approaches that target CD44 may overcome clinical lenalidomide resistance.

Topics: Animals; Antibodies, Monoclonal; Antibody-Dependent Cell Cytotoxicity; Antineoplastic Agents; Cell Adhesion; Cell Line, Tumor; Disease Models, Animal; Drug Resistance, Neoplasm; Gene Expression; Humans; Hyaluronan Receptors; Hyaluronic Acid; Immunologic Factors; Lenalidomide; Mice; Multiple Myeloma; Protein Binding; Thalidomide; Tretinoin; Xenograft Model Antitumor Assays

Patients with alcoholic liver disease (ALD) have vitamin A (VA) deficiency and an enhanced immune response associated with disease severity. All-trans retinoic acid (ATRA), a VA-active metabolite, has anti-inflammatory effects and its deficiency could contribute to the exacerbated proinflammatory reaction. The aim of this study was to investigate the effects of ATRA/VA deficiency and supplementation on the monocyte response in ALD.. Vitamin A and ATRA plasma levels were quantified in ALD patients and healthy subjects (HS). The in vitro effect of ATRA on lipopolysaccharide (LPS)-induced TNF-α production by human peripheral blood mononuclear cells (PBMC) was assessed by ELISA and RT-PCR. The activation pattern of peritoneal macrophages (PerMΦ) and circulating monocytes isolated from VA-deficient mice and ALD patients, respectively, was evaluated by flow cytometry, quantification of TNF-α and NO2 production.. Alcoholic liver disease patients (n = 85) showed plasmatic VA deficiency that was correlated with scores of severity and with the hepatic venous pressure gradient. ATRA levels correlated significantly with VA levels. In vitro, ATRA pretreatment decreased the overproduction of TNF-α by LPS-stimulated PBMC of ALD patients. In vivo, VA deficiency in mice was associated with increased activation of PerMΦ, while oral ATRA supplementation normalized it.. For the first time, we show that VA/ATRA deficiencies in ALD patients are associated with disease severity. Furthermore, our data strongly suggest that the VA deficiency observed in ALD patients might participate in the pathophysiology of the disease by priming immune cells, and that ATRA supplementation could downregulate the deleterious proinflammatory state in cirrhosis and might thus be of therapeutic use.

Topics: Adult; Aged; Animals; Case-Control Studies; Cells, Cultured; Disease Models, Animal; Down-Regulation; Female; Humans; Lipopolysaccharides; Liver Cirrhosis, Alcoholic; Macrophage Activation; Macrophages, Peritoneal; Male; Mice; Mice, Inbred C57BL; Middle Aged; Monocytes; RNA, Messenger; Tretinoin; Tumor Necrosis Factor-alpha; Vitamin A; Vitamin A Deficiency

A T-helper 17 (Th17)/regulatory T (Treg) imbalance has been suggested recently to play a role in the development of periodontitis. All-trans retinoic acid (ATRA) has been reported to modulate Th17/Treg imbalances in some diseases. However, the effect of ATRA on periodontitis remains unknown. This study observes the effect of ATRA on Th17/Treg imbalance modulation in experimental periodontitis.. Experimental periodontitis was induced in mice by oral infection with Porphyromonas gingivalis (P. gingivalis). ATRA was orally administered every other day. Alveolar bone resorption (ABR) was estimated by measuring the distance from the cemento-enamel junction to the alveolar bone crest. CD4(+) T-cell subsets in the cervical lymph nodes (CLNs) and spleen were analyzed by flow cytometry. Th17/Treg cell-related cytokine messenger ribonucleic acid expression was quantified by real-time reverse transcription-polymerase chain reaction.. The present data shows that ATRA suppressed ABR and inhibited inflammatory cell infiltration into periodontal tissues. These effects were closely associated with reduced CD4(+) retinoid-related orphan receptor γτ(+) cells and increased CD4(+) forkhead box P3(+) cells in the CLNs. Furthermore, ATRA downregulated interleukin (IL)-17A expression and upregulated IL-10 and transforming growth factor-β1 expression in both the CLNs and P. gingivalis-infected gingival tissues.. These results suggest that ATRA modulation of the Th17/Treg imbalance provides protection against periodontitis by enhancing Treg cell activation and inhibiting Th17 cell activation. These results indicate the potential for clinical prevention of periodontitis.

Topics: Administration, Oral; Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; CD4-Positive T-Lymphocytes; Disease Models, Animal; Female; Forkhead Transcription Factors; Interleukin-10; Interleukin-17; Lymph Nodes; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Nuclear Receptor Subfamily 1, Group F, Member 3; Periodontitis; Porphyromonas gingivalis; Random Allocation; Spleen; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta1; Tretinoin

CHARGE syndrome is a multiple congenital anomaly disorder that leads to life-threatening birth defects, such as choanal atresia and cardiac malformations as well as multiple sensory impairments, that affect hearing, vision, olfaction and balance. CHARGE is caused by heterozygous mutations in CHD7, which encodes an ATP-dependent chromatin remodeling enzyme. Identification of the mechanisms underlying neurological and sensory defects in CHARGE is a first step toward developing treatments for CHARGE individuals. Here, we used mouse models of Chd7 deficiency to explore the function of CHD7 in the development of the subventricular zone (SVZ) neural stem cell niche and inner ear, structures that are important for olfactory bulb neurogenesis and hearing and balance, respectively. We found that loss of Chd7 results in cell-autonomous proliferative, neurogenic and self-renewal defects in the perinatal and mature mouse SVZ stem cell niche. Modulation of retinoic acid (RA) signaling prevented in vivo inner ear and in vitro neural stem cell defects caused by Chd7 deficiency. Our findings demonstrate critical, cooperative roles for RA and CHD7 in SVZ neural stem cell function and inner ear development, suggesting that altered RA signaling may be an effective method for treating Chd7 deficiency.

Topics: Animals; Brain; Cerebral Ventricles; CHARGE Syndrome; Disease Models, Animal; DNA-Binding Proteins; Ear, Inner; Humans; Mice; Mice, Knockout; Mutation; Neural Stem Cells; Neurogenesis; Olfactory Bulb; Signal Transduction; Stem Cell Niche; Tretinoin

One suitable approach to enhancing multiple sclerosis (MS) treatment is combination of available medications to provide more desirable outcomes. Immunomodulatory effects of atorvastatin and/or all-trans retinoic acid (ATRA) were determined in previous studies. The present study was set out to investigate the synergistic effects of combination therapy by suboptimal doses of atorvastatin and ATRA in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE was induced by MOG35-55 in female C57BL/6 mice. Therapies were initiated at day 12 post immunization when the mice developed a disability score and continued throughout the study until the day 33 when animals were sacrificed. Therapeutic treatment with half doses of atorvastatin and ATRA in combination has synergistic benefits causing the regression of clinical and neuropathological features of EAE more favorable than treatment with full doses of either drug alone. Without any advantage in anti-proliferative effect, combination treatment significantly reduced the secretion of pro-inflammatory cytokine interleukin-17 and conversely, increased the production of anti-inflammatory cytokine interleukin-10 more prominent than either drug alone. Furthermore, FoxP3+Treg cells were significantly increased only in combination treatment. In conclusion, combined atorvastatin and ATRA have immunomodulatory synergistic benefits and this pharmacological approach may be as a useful strategy to control MS.

Topics: Animals; Atorvastatin; Brain; Cytokines; Disease Models, Animal; Drug Synergism; Encephalomyelitis, Autoimmune, Experimental; Female; Forkhead Transcription Factors; Heptanoic Acids; Mice; Multiple Sclerosis; Pyrroles; T-Lymphocytes, Regulatory; Tretinoin; Weight Loss

Reactive oxygen species play a role in a number of degenerative conditions including osteoporosis. Flavonoids as phyto-oestrogens exert physiological effects against oxidative stress diseases. We developed a retinoic acid-induced bone loss model of rats to assess whether flavonoids and alendronate as positive control have role against oxidative stress and mineral contents in osteoporosis in vivo.. Three-month-old female rats of the Y59 strain were given quercetin, chrysin, naringenin (100 mg kg(-1)) or alendronate (40 mg kg(-1), a positive control) immediately before retinoic acid treatment (80 mg kg(-1)) once daily for 14 days by a single intragastric (i.g.) application. In the second part of the study, we assessed the effect of those flavonoids on the skeletal system of healthy rats using single i.g. application on the respective flavonoids during 14 days. Twenty-four hours after the treatment, we analysed bone mineral density and the total content of bone calcium and phosphorus in the femur, the geometric and physical characteristics of thigh bones and lipid peroxidation and glutathione levels of liver and kidney cells.. All flavonoids improved the decrease in bone weight coefficient, the length and the diameter of the bone, the content of bone ash and calcium and phosphorus content induced by retinoic acid. Chrysin and quercetin showed promise as preventive agents. Flavonoids were superior to alendronate according to some criteria.. These results suggest that the dietary flavonoids could reduce retinoic acid-induced oxidative stress and bone loss and that flavonoids may be useful therapeutics for prevention of skeletal diseases.

Topics: Animals; Bone Density; Calcium; Disease Models, Animal; Female; Femur; Flavanones; Flavonoids; Lipid Peroxidation; Minerals; Osteoporosis; Oxidative Stress; Phosphorus; Quercetin; Rats; Tretinoin

Myeloid-derived suppressor cells (MDSCs) are emerging as potential promoters of metastatic tumor growth, and there is interest in targeting immature MDSCs by inducing their differentiation into more mature myeloid cells. We used all-trans retinoic acid (ATRA) to differentiate MDSCs in mice bearing metastatic 4T1 or 4TO7 murine mammary tumors, and assessed the immune-suppressive mechanisms and potencies of different myeloid cell subpopulations. Metastatic mammary tumors induced the accumulation of distinct populations of immature CD11b(+)Gr1(+)F4/80(-)Ly6C(mid)Ly6G(+) MDSCs ("Gr1(+) cells") and mature CD11b(+)Gr1(-)F4/80(+) cells ("F4/80(+) cells") in metastatic target organs. ATRA triggered the differentiation of Gr1(+) cells into F4/80(+) cells in the lungs and, unexpectedly, enhanced pulmonary metastatic tumor growth. We found that F4/80(+)Ly6C(-)Ly6G(-) mature macrophages (Ms) were up to 30-fold more potent immune suppressors than Gr1(+) cells on a per-cell basis, which we postulate may contribute to the increased metastatic growth observed with ATRA treatment. F4/80(+) cells and Gr1(+) cells used different reactive oxygen species (ROS)-mediated mechanisms of immunosuppression ex vivo, with F4/80(+) cells producing higher levels of ROS, which is consistent with their superior immunosuppressive abilities. These data highlight the potent immunosuppressive functions of Ms, reveal that Ms can suppress T cell responses via ROS production, and suggest that ROS inhibitors may be useful in promoting antitumor immune responses. Our findings also caution against using ATRA to modulate myeloid cell differentiation and function to treat breast cancer metastases in the lung, and support the development of therapeutic strategies to enhance antitumor immunity by targeting myeloid cells as a collective group.

Topics: Animals; Breast Neoplasms; Cell Differentiation; Disease Models, Animal; Female; Immunophenotyping; Lung Neoplasms; Macrophages; Mice; Mice, Transgenic; Myeloid Cells; Neoplasm Metastasis; Phenotype; Reactive Oxygen Species; Receptors, Cell Surface; T-Lymphocytes; Tretinoin

The high mortality rate in congenital diaphragmatic hernia (CDH) is attributed to pulmonary hypoplasia (PH). Insulin-like growth factor 2 (IGF2) is an important regulator of fetal growth. The highest levels of IGF2 expression are found in the placenta, which are negatively regulated by decidual retinoid acid receptor alpha (RARα). It has been demonstrated that prenatal administration of retinoic acid (RA) suppresses decidual RARα expression. Previous studies have further shown that prenatal administration of RA can reverse PH in nitrofen-induced CDH model. In IGF2 knockout animals, low levels of IGF2 are associated with decreased placental growth and PH. We therefore hypothesized that nitrofen decreases trophoblastic IGF2 expression and prenatal administration of RA increases it through decidual RARα in the nitrofen-induced CDH model.. Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). RA was given intraperitoneally on D18, D19 and D20. Fetuses were harvested on D21 and divided into three groups: control, CDH and nitrofen+RA. Immunohistochemistry was performed to evaluate decidual RARα and trophoblastic IGF2 expression. Protein levels of IGF2 in serum, intra-amniotic fluid and left lungs were measured by enzyme-linked immunosorbent assay.. Significant growth retardation of placenta and left lungs was observed in the CDH group compared to control and nitrofen+RA group. Markedly increased decidual RARα and decreased IGF2 immunoreactivity were found in the CDH group compared to control and nitrofen+RA group. Significantly decreased IGF2 protein levels were detected in serum, intra-amniotic fluid and left lungs in the CDH group compared to control and nitrofen+RA group.. Our findings suggest that nitrofen may disturb trophoblastic IGF2 expression through decidual RARα resulting in retarded placental growth and PH in the nitrofen-induced CDH. Prenatal administration of RA may promote lung and placental growth by increasing trophoblastic IGF2 expression.

Topics: Animals; Antineoplastic Agents; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Gene Expression Regulation, Developmental; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Insulin-Like Growth Factor II; Lung; Phenyl Ethers; Pregnancy; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin; Trophoblasts; Up-Regulation

Despite technical advances in the surgical/medical care of anorectal malformation (ARM), persistent unsatisfactory postoperative bowel habit has been attributed to histopathologic abnormalities of the distal rectum/pouch (DRP) and hypoplasia of anal sphincter muscles (ASM). We used Sox10-Venus mice with ARM induced by all-trans retinoic acid (ATRA) to investigate neural crest cell (NCC) innervation in the DRP and ASM.. Pregnant Sox10-Venus mice were administered single doses of 50, 70, or 100 mg/kg of ATRA on embryonic day 8.5 (E8.5) then sacrificed on either E16.5 or E19.5. Bowel specimens comprising the anorectum were examined using fluorescence microscopy without immunohistochemical staining (FMIS). Anti-PGP9.5 was used to delineate ganglion cells and anti-SMA for smooth muscles.. The appropriate dose of ATRA for inducing ARM was 50 mg/kg. Under FMIS, all ARM embryos (n = 5; all high type; 3 male:2 female) had less NCC innervation with thick Venus-positive nerve fibers in the DRP compared with normal embryos (n = 8); there was abnormal NCC innervation in the DRP and absent ASM in ARM mice.. We are the first to delineate abnormal enteric nervous system innervation in the DRP of ARM mice without using immunohistochemical staining techniques thus allowing specimens to be examined without any distortion.

Topics: Abnormalities, Multiple; Anal Canal; Animals; Anorectal Malformations; Anus, Imperforate; Disease Models, Animal; Female; Intestines; Male; Mice; Microscopy, Fluorescence; Neural Crest; Rectum; Tretinoin

We assessed feeding-related developmental anomalies in the LgDel mouse model of chromosome 22q11 deletion syndrome (22q11DS), a common developmental disorder that frequently includes perinatal dysphagia--debilitating feeding, swallowing and nutrition difficulties from birth onward--within its phenotypic spectrum. LgDel pups gain significantly less weight during the first postnatal weeks, and have several signs of respiratory infections due to food aspiration. Most 22q11 genes are expressed in anlagen of craniofacial and brainstem regions critical for feeding and swallowing, and diminished expression in LgDel embryos apparently compromises development of these regions. Palate and jaw anomalies indicate divergent oro-facial morphogenesis. Altered expression and patterning of hindbrain transcriptional regulators, especially those related to retinoic acid (RA) signaling, prefigures these disruptions. Subsequently, gene expression, axon growth and sensory ganglion formation in the trigeminal (V), glossopharyngeal (IX) or vagus (X) cranial nerves (CNs) that innervate targets essential for feeding, swallowing and digestion are disrupted. Posterior CN IX and X ganglia anomalies primarily reflect diminished dosage of the 22q11DS candidate gene Tbx1. Genetic modification of RA signaling in LgDel embryos rescues the anterior CN V phenotype and returns expression levels or pattern of RA-sensitive genes to those in wild-type embryos. Thus, diminished 22q11 gene dosage, including but not limited to Tbx1, disrupts oro-facial and CN development by modifying RA-modulated anterior-posterior hindbrain differentiation. These disruptions likely contribute to dysphagia in infants and young children with 22q11DS.

Topics: Animals; Animals, Newborn; Body Patterning; Chromosome Deletion; Cranial Nerves; Craniofacial Abnormalities; Deglutition; Deglutition Disorders; DiGeorge Syndrome; Disease Models, Animal; Embryo, Mammalian; Feeding Behavior; Female; Gene Dosage; Gene Expression Regulation, Developmental; Male; Mice; Phenotype; Rhombencephalon; Signal Transduction; T-Box Domain Proteins; Tretinoin

There is increasing evidence that vitamin A deficiency in utero correlates with abnormal airway smooth muscle (SM) function in postnatal life. The bioactive vitamin A metabolite retinoic acid (RA) is essential for formation of the lung primordium; however, little is known about the impact of early fetal RA deficiency on postnatal lung structure and function. Here, we provide evidence that during murine lung development, endogenous RA has a key role in restricting the airway SM differentiation program during airway formation. Using murine models of pharmacological, genetic, and dietary vitamin A/RA deficiency, we found that disruption of RA signaling during embryonic development consistently resulted in an altered airway SM phenotype with markedly increased expression of SM markers. The aberrant phenotype persisted postnatally regardless of the adult vitamin A status and manifested as structural changes in the bronchial SM and hyperresponsiveness of the airway without evidence of inflammation. Our data reveal a role for endogenous RA signaling in restricting SM differentiation and preventing precocious and excessive SM differentiation when airways are forming.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchoconstrictor Agents; Cell Differentiation; Diet; Disease Models, Animal; Female; Lung; Methacholine Chloride; Mice; Mice, Knockout; Muscle, Smooth; Oligonucleotide Array Sequence Analysis; Phenotype; Pregnancy; Signal Transduction; Tretinoin; Vitamin A; Vitamin A Deficiency

Epididymitis, one of the most common urological diseases, can lead to the destruction of the epididymal duct and cause transient or permanent sterility. The aim of this study was to investigate the functions and related mechanisms of all trans retinoic acid (atRA) in alleviating the acute inflammation of epididymitis.. The mouse model of the epididymitis was induced by injecting Escherichia coli into the cauda epididymis. atRA was administrated for five consecutive days through intraperitoneal injection. The expression levels of inflammatory cytokines were measured by real-time PCR and Western blot. In addition, cultured primary mouse epididymal epithelial cells were treated with different concentrations of atRA and RAR antagonists to identify whether the effect of atRA was mediated through RAR.. Our results demonstrate that atRA ameliorates the inflammation in mouse epididymitis by decreasing the expression of the pro-inflammatory cytokines and increasing the expression of anti-inflammatory factors including TGF-β1 and IL-10. Our results show that the upregulating effect of atRA on TGF-β1 was mediated by RARα, and the enhancing effect of atRA on IL-10 expression was mediated via RARβ.. These new results suggest that atRA is involved in regulating the inflammatory response of epididymis.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Disease Models, Animal; Epididymis; Epididymitis; Escherichia coli; Escherichia coli Infections; Inflammation; Interleukin-10; Male; Mice; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Transforming Growth Factor beta1; Tretinoin; Up-Regulation

Chronic cholestasis results in liver injury and eventually liver failure. Although ursodeoxycholic acid (UDCA) showed limited benefits in primary biliary cirrhosis, there is an urgent need to develop alternative therapy for chronic cholestatic disorders. Previous studies from our laboratory demonstrated that all-trans-retinoic acid (atRA) is a potent suppressor of CYP7A1, the rate-limiting enzyme in bile acid synthesis. atRA also repressed the expression of tumor growth factor-β and collagen 1A1 in activated primary human stellate cells and LX2 cells. When administered together with UDCA to bile duct-ligated rats, this combined therapy significantly reduced the bile acid pool size and improved liver conditions. To further examine whether atRA alone or in combination with UDCA has greater beneficial effects than UDCA treatment alone, we assessed this treatment in two additional chronic cholestatic rodent models: α-naphthylisothiocyanate (ANIT)-treated rats and the Mdr2(-/-) (Abcb4(-/-)) knockout mouse. atRA alone significantly reduced bile duct proliferation, inflammation, and hydroxyproline levels in ANIT-treated rats, whereas the combination of atRA and UDCA significantly reduced plasma bile salt level compared with UDCA treatment. atRA alone or in combination with UDCA significantly reduced plasma levels of alkaline phosphatase and bile salts in 12-week-old Mdr2(-/-) mice. Reduced bile duct proliferation and inflammation were also observed in the livers of these mice. Together, atRA alone or in combination with UDCA significantly reduced the severity of liver injury in these two animal models, further supporting the combination treatment of atRA and UDCA as a potential new therapy for patients with chronic cholestatic liver disease who have not responded fully to UDCA.

Topics: 1-Naphthylisothiocyanate; Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Bile Acids and Salts; Cell Proliferation; Cholagogues and Choleretics; Cholestasis; Chronic Disease; Disease Models, Animal; Drug Therapy, Combination; Liver; Male; Mice; Mice, Knockout; Rats; Rats, Sprague-Dawley; Tretinoin; Ursodeoxycholic Acid

Zonula occludens-1 (ZO-1) and occludin are important tight junction (TJ)-associated proteins, which are expressed in the retinal pigment epithelium (RPE)-choroid complex. Retinoic acid (RA) is a regulator of eye growth and may play an important role in forming functional TJs. The aim of this study was to detect the changes that occur in the expression of ZO-1 and occludin in the RPE-choroid complex of guinea pigs with lens-induced myopia (LIM), and to investigate the effect of RA on TJ-associated proteins in vivo. We developed an animal model of myopia by placing a -6.00 D negative lens on the right eyes of 3-week-old guinea pigs. The refractive error and axial length of the eye were measured on days 0, 3, 7 and 14. High-performance liquid chromatography (HPLC) was performed to detect the changes in endogenous RA in the RPE-choroid complex. The expression of ZO-1 and occludin was observed by immunofluorescence and assayed by western blot analysis. Additionally, 2 µl LE540 (2.5 µg/µl), an antagonist of RA receptors (RARs), was injected into the vitreous chamber of the eyes of guinea pigs with LIM and 2 µl phosphate-buffered saline (PBS) (2.5 µg/µl) were injected as a negative control. We observed no obvious change in RA, ZO-1 and occludin expression in the normal control group within 14 days. In the LIM and LIM plus PBS groups, the level of RA and the expression of ZO-1 and occludin in the RPE-choroid complex significantly increased within 14 days along with the development of myopia. However, the level of RA was inhibited and the expression of TJ-associated proteins decreased in the eyes of guinea pigs with LIM following the injection of LE540. Thus, we consider that the expression of ZO-1 and occludin is increased in the RPE-choroid complex during the development of myopia. This change in expression may be regulated by RA, a factor known to be involved in the regulation of eye growth.

Topics: Animals; Blotting, Western; Choroid; Disease Models, Animal; Fluorescent Antibody Technique; Guinea Pigs; Lens, Crystalline; Myopia; Refractometry; Retinal Pigment Epithelium; Tight Junction Proteins; Tight Junctions; Tretinoin; Vision, Ocular

To investigate the apoptotic gene expression of placenta in an all-trans-retinoic acid (ATRA) induced fetus congenital clubfoot pregnant rat model.. Sprague-Dawley (SD) rats were divided randomly into ATRA-exposed group and control group. On day 10 of pregnancy, a dose of 120 mg/kg ATRA dissolved in mineral oil was given intragastrically to the rats in the ATRA-exposed group and equivalent volume of mineral oil was given intragastrically to the control rats. Fetuses were delivered on day 20 of pregnancy, the placenta was collected for the pathological and biochemical analysis.. Clubfoot-like deformity fetuses were observed in the ATRA-exposed group and none with deformity was found in the control group. The pro-apoptosis in placenta of ATRA-exposed group was measured by flow cytometry. Moreover, compared with the control group, lower expression of Bcl-2 and higher expression of BAX were found in the ATRA-exposed group in both mRNA and protein level. Immunohistochemical labeling of Bcl-2 in the control group was more intense while BAX labeling in the ATRA-exposed group was more intense. Additionally, the caspase-3 activity was also significantly increased in the ATRA-exposed group than control group.. In our research, we found a pro-apoptosis in placenta in the ATRA-exposed pregnant rats, indicating a possible association between placental apoptosis and congenital clubfoot.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Caspase 3; Clubfoot; Disease Models, Animal; Female; Flow Cytometry; Gene Expression Regulation, Developmental; Gestational Age; Immunohistochemistry; Placenta; Pregnancy; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tretinoin

The intracellular concentration of retinoic acid is determined by two sequential oxidation reactions that convert retinol to retinoic acid. We recently demonstrated that retinoic acid synthesis is significantly impaired in glomeruli of HIV-1 transgenic mice (Tg26), a murine model of HIV-associated nephropathy. This impaired retinoic acid synthesis correlates with reduced renal expression of retinol dehydrogenase 9, which catalyzes the rate-limiting step of retinoic acid synthesis by converting retinol to retinal. Because retinoic acid has renal protective effects and can induce podocyte differentiation, we hypothesized that restoration of retinoic acid synthesis could slow the progression of renal disease. Herein, we demonstrate that overexpression of retinol dehydrogenase 9 in cultured podocytes induces the expression of podocyte differentiation markers. Furthermore, we confirm that podocyte-specific overexpression of retinol dehydrogenase 9 in mice with established kidney disease due to either HIV-associated nephropathy or adriamycin-induced nephropathy decreases proteinuria, attenuates kidney injury, and restores podocyte differentiation markers. Our data suggest that restoration of retinoic acid synthesis could be a new approach to treat kidney disease.

Topics: Alcohol Oxidoreductases; Animals; Biomarkers; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Gene Expression; Kidney; Mice; Mice, Transgenic; Podocytes; Proteinuria; Recombinant Fusion Proteins; RNA, Messenger; Tretinoin; Up-Regulation

A fundamental goal in cancer biology is to identify the cells and signalling pathways that are keys to induce tumour regression. Here we use a spontaneously self-regressing tumour, cutaneous keratoacanthoma (KAs), to identify physiological mechanisms that drive tumour regression. By using a mouse model system that recapitulates the behaviour of human KAs, we show that self-regressing tumours shift their balance to a differentiation programme during regression. Furthermore, we demonstrate that developmental programs utilized for skin hair follicle regeneration, such as Wnt, are hijacked to sustain tumour growth and that the retinoic acid (RA) signalling pathway promotes tumour regression by inhibiting Wnt signalling. Finally, we find that RA signalling can induce regression of malignant tumours that do not normally spontaneously regress, such as squamous cell carcinomas. These findings provide new insights into the physiological mechanisms of tumour regression and suggest therapeutic strategies to induce tumour regression.

Topics: Animals; Carcinoma, Squamous Cell; Disease Models, Animal; Hair Follicle; Keratoacanthoma; Mice; Remission, Spontaneous; Skin Neoplasms; Stem Cells; Tretinoin; Wnt Signaling Pathway

Retinopathy of prematurity (ROP) is directly associated with abnormal expression of retinal vascular endothelial growth factor (VEGF) in premature neonates. This study was to investigate whether the systemic administration of retinoic acid (RA) regulates retinal VEGF expression and prevents retinal neovascularization and retinopathy in the oxygen-induced retinopathy (OIR) mouse model.. C57BL/6 mice were subjected to OIR by exposure to 75% oxygen from postnatal day (P) 7 to 12 of age. RA was intraperitoneally injected daily to pups from P6 to P9. Retinal whole mount staining and image analysis, immunostaining, Western blotting, quantitative RT-PCR, TUNEL assay, and electroretinography were performed to evaluate the effects of RA on VEGF expression, retinal neovascularization, and retinal neuron functions.. Systemic administration of RA in OIR mice promoted retinal VEGF mRNA and protein expression in phase I; the stabilized level of VEGF in phase I supported retinal vascular development and counteracted vaso-obliteration in OIR mice. Subsequently, the excessive generation of VEGF in phase II was attenuated; the retinal vascular leakage and apoptotic cells were significantly ameliorated. As a result, RA significantly prevented the development of hypoxia-induced retinal neovascularization and retinopathy in OIR mice and improved the functional recovery of retinal neurons downstream of photoreceptor cells as measured by focal electroretinography.. Systemic administration of RA regulates retinal VEGF expression and supports retinal vascular development in OIR mouse model. We propose that systemic administration of RA to extremely low birth weight, preterm infants during oxygen therapy could potentially be an effective therapeutic approach for the prevention of ROP.

Topics: Animals; Animals, Newborn; Antineoplastic Agents; Apoptosis; Blotting, Western; Disease Models, Animal; Gene Expression Regulation, Developmental; Hyperoxia; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Retina; Retinal Neovascularization; Retinopathy of Prematurity; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin; Up-Regulation; Vascular Endothelial Growth Factor A

Dengue virus (DENV) is estimated to cause 390 million infections each year, but there is no licensed vaccine or therapeutic currently available.. We describe a novel, high-throughput screen to identify compounds inhibiting the interaction between DENV nonstructural protein 5 and host nuclear transport proteins. We document the antiviral properties of a lead compound against all 4 serotypes of DENV, antibody-dependent enhanced (ADE) infection, and ex vivo and in vivo DENV infections. In addition, we use quantitative reverse-transcription polymerase chain reaction to examine cellular effects upon compound addition.. We identify N-(4-hydroxyphenyl) retinamide (4-HPR) as effective in protecting against DENV-1-4 and DENV-1 ADE infections, with 50% effective concentrations in the low micromolar range. 4-HPR but not the closely related N-(4-methoxyphenyl) retinamide (4-MPR) could reduce viral RNA levels and titers when applied to an established infection. 4-HPR but not 4-MPR was found to specifically upregulate the protein kinase R-like endoplasmic reticulum kinase arm of the unfolded protein response. Strikingly, 4-HPR but not 4-MPR restricted infection in peripheral blood mononuclear cells and in a lethal ADE-infection mouse model.. 4-HPR is a novel antiviral that modulates the unfolded protein response, effective against DENV1-4 at concentrations achievable in the plasma in a clinical setting, and provides protection in a lethal mouse model.

Topics: Active Transport, Cell Nucleus; Animals; Antiviral Agents; Carrier Proteins; Cell Line; Dengue; Dengue Virus; Disease Models, Animal; eIF-2 Kinase; Fenretinide; Humans; Mice; Protein Binding; Protein Transport; Signal Transduction; Tretinoin; Unfolded Protein Response; Viral Nonstructural Proteins; Virus Replication

Myelomeningocele (MMC) is a common congenital malformation and the most severe form of spina bifida characterized by the protrusion of spinal cord and meninges through the spinal defect. Our objective was to improve the assessment of congenital vertebral defects in animal models of MMC using three-dimensional high resolution micro-computed tomography (micro-CT) imaging and quantitative digital analyses methods.. Lumbosacral MMC was induced in fetal rats by exposure of pregnant mothers at embryonic day 10 (E10) to all-trans retinoic acid, and rats were examined at term (embryonic day 22). The axial skeleton was examined in an MMC model for the first time using ex vivo micro-CT at 10 μm voxel resolution to allow high resolution two-dimensional and three-dimensional characterization of anomalies in lumbosacral vertebrae, and quantitative assessment of distances between dorsal vertebral arches in lumbosacral regions in MMC rats, compared with normal controls.. We observed, in detail, skeletal defects in lumbosacral vertebra of MMC rats, including in the morphology of individual dorsal vertebral arches. Use of high resolution micro-CT has also enabled us to identify the delayed (nonfused) or absent ossification in vertebral bodies, increased fusion of adjacent lateral vertebral elements, and quantify the extent of dorsal arch widening. Distances between dorsal vertebral arches showed statistically significant increases from L5 through S4 in MMC rats, compared with normal controls.. High-resolution micro-CT combined with digital quantification methods is a powerful technique ideally suited for precise assessment of complex congenital skeletal abnormalities such as examined in this rodent model of MMC.

Topics: Animals; Disease Models, Animal; Female; Fetus; Humans; Image Processing, Computer-Assisted; Lumbosacral Region; Meningomyelocele; Pregnancy; Rats; Spine; Tretinoin; X-Ray Microtomography

Inflammatory bowel disease (IBD) is characterized by excessive innate immune cell activation, which is responsible for tissue damage and induction of adaptive immune responses. All-trans retinoic acid (ATRA), the ligand of retinoic acid receptors (RAR), has been previously shown to regulate adaptive immune responses and restore Th17/Treg balance, while its role in regulation of innate immune cell function such as macrophages remains to be elucidated. The study was performed to explore the effect of ATRA on regulation of innate immune responses during dextran sulfate sodium (DSS) induced murine colitis. The mice with DSS colitis were administered with vehicle, ATRA, or LE135. Colitis was evaluated by clinical symptoms, tissue myeloperoxidase (MPO) activity, and the expressions of CD68 and nuclear factor (NF) κB p65, and tumor necrosis factor (TNF) level in inflamed colon. RAW 264.7 cells were pretreated with vehicle, ATRA, or LE135, followed by LPS challenge in vitro. ATRA administration ameliorates DSS-induced colitis evidenced with decreased TNF level and CD68 expression, while LE135 leads to exacerbation of colitis. ATRA treatment in vitro dampens LPS induced NF-κB activation and TNF production of RAW 264.7 cells. Together, our data show a crucial role of ATRA in the progress of acute colitis through inhibiting NF-κB activation, and suggest that ATRA represents a novel therapeutic approach for the management of IBD.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Cell Line; Colitis; Dextran Sulfate; Disease Models, Animal; Female; Lipopolysaccharides; Macrophages; Mice; Neutrophil Infiltration; NF-kappa B; Peroxidase; Signal Transduction; Tretinoin; Tumor Necrosis Factors

Acute promyelocytic leukemia (APL) is characterized by the t(15;17)-associated PML-RARA fusion gene. We have previously found that MIR125B1 is highly expressed in patients with APL and may be associated with disease pathogenesis; however, the mechanism by which MIR125B1 exerts its oncogenic potential has not been fully elucidated. Here, we demonstrated that MIR125B1 abundance correlates with the PML-RARA status. MIR125B1 overexpression enhanced PML-RARA expression and inhibited the ATRA-induced degradation of the PML-RARA oncoprotein. RNA-seq analysis revealed a direct link between the PML-RARA degradation pathway and MIR125B1-arrested differentiation. We further demonstrated that the MIR125B1-mediated blockade of PML-RARA proteolysis was regulated via an autophagy-lysosomal pathway, contributing to the inhibition of APL differentiation. Furthermore, we identified DRAM2 (DNA-damage regulated autophagy modulator 2), a critical regulator of autophagy, as a novel target that was at least partly responsible for the function of MIR125B1 involved in autophagy. Importantly, the knockdown phenotypes for DRAM2 are similar to the effects of overexpressing MIR125B1 as impairment of PML-RARA degradation, inhibition of autophagy, and myeloid cell differentiation arrest. These effects of MIR125B1 and its target DRAM2 were further confirmed in an APL mouse model. Thus, MIR125B1 dysregulation may interfere with the effectiveness of ATRA-mediated differentiation through an autophagy-dependent pathway, representing a novel potential APL therapeutic target.

Topics: Adolescent; Animals; Autophagy; Base Sequence; Cell Differentiation; Cell Line, Tumor; Child; Child, Preschool; Disease Models, Animal; Female; Gene Expression Profiling; Humans; Infant; Infant, Newborn; Leukemia, Promyelocytic, Acute; Lysosomes; Male; Membrane Proteins; Mice; MicroRNAs; Molecular Sequence Data; Oncogene Proteins, Fusion; Phagosomes; Proteolysis; Tretinoin

The intestinal mucosa is the largest body surface exposed to the environment. While there are common features when comparing immune responses along the intestinal mucosa, the small bowel and colon exhibit striking differences in their mechanisms driving immune regulation. The vitamin A (VA) metabolite all-trans retinoic acid (RA) signaling via RA nuclear receptors plays a key role in immune homeostasis in the small bowel, and recent work indicates that RA is required for establishing immune tolerance to dietary antigens in the upper intestinal tract by inducing α4β7(+)CCR9(+) gut-tropic TREG. In contrast, microbiota-specific TREG in the colon do not appear to require RA, but can be regulated by short-chain fatty acids (SCFA), microbial metabolites that signal through the G protein-coupled receptor GPR43. Moreover, TREG do not need CCR9 to home to the colon, but utilize another G protein-coupled receptor, GPR15, which is upregulated by SCFA. Thus, the mechanisms governing intestinal tolerance to dietary antigens in the upper digestive tract differ from those controlling tolerance to the microbiota in the colon, with RA and SCFA playing key complementary roles in their respective compartments. In addition to VA and SCFA, recent studies have highlighted the roles of other dietary and microbial metabolites that influence immune cell homeostasis across the small and large bowel including dietary ligands for aryl hydrocarbon receptor and microbiota-modified bile acids. Understanding the complex and dynamic interplay between dietary metabolites and commensal microbiota within the intestinal microenvironment could therefore inform novel strategies for the treatment of food allergies and inflammatory bowel diseases.

Topics: Animals; Cell Differentiation; Colon; Dendritic Cells; Disease Models, Animal; Fatty Acids, Volatile; Homeostasis; Humans; Immune Tolerance; Intestinal Mucosa; Intestines; Microbiota; Receptors, G-Protein-Coupled; Th1 Cells; Th2 Cells; Tretinoin

Oral all-trans retinoic acid (atRA) has been shown to reduce the formation of neointimal hyperplasia; however, the dose required was 30 times the chemotherapeutic dose, which already has reported side effects. As neointimal formation is a localized process, new approaches to localized delivery are required. This study assessed whether atRA within a citrate-based polyester, poly(1,8 octanediolcitrate) (POC), perivascular membrane would prevent neointimal hyperplasia following arterial injury. atRA-POC membranes were prepared and characterized for atRA release via high-performance liquid chromatography with mass spectrometry detection. Rat adventitial fibroblasts (AF) and vascular smooth muscle cells (VSMC) were exposed to various concentrations of atRA; proliferation, apoptosis, and necrosis were assessed in vitro. The rat carotid artery balloon injury model was used to evaluate the impact of the atRA-POC membranes on neointimal formation, cell proliferation, apoptosis, macrophage infiltration, and vascular cell adhesion molecule 1 (VCAM-1) expression in vivo. atRA-POC membranes released 12 μg of atRA over 2 wk, with 92% of the release occurring in the first week. At 24 h, atRA (200 μmol/l) inhibited [(3)H]-thymidine incorporation into AF and VSMC by 78% and 72%, respectively (*P = 0.001), with negligible apoptosis or necrosis. Histomorphometry analysis showed that atRA-POC membranes inhibited neointimal formation after balloon injury, with a 56%, 57%, and 50% decrease in the intimal area, intima-to-media area ratio, and percent stenosis, respectively (P = 0.001). atRA-POC membranes had no appreciable effect on apoptosis or proliferation at 2 wk. Regarding biocompatibility, we found a 76% decrease in macrophage infiltration in the intima layer (P < 0.003) in animals treated with atRA-POC membranes, with a coinciding 53% reduction in VCAM-1 staining (P < 0.001). In conclusion, perivascular delivery of atRA inhibited neointimal formation and restenosis. These data suggest that atRA-POC membranes may be suitable as localized therapy to inhibit neointimal hyperplasia following open cardiovascular procedures.

Topics: Adventitia; Animals; Apoptosis; Carotid Artery Injuries; Carotid Artery, Common; Carotid Stenosis; Cell Proliferation; Cells, Cultured; Citrates; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Carriers; Fibroblasts; Hyperplasia; Macrophages; Male; Membranes, Artificial; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Neointima; Polymers; Rats, Sprague-Dawley; Recurrence; Time Factors; Tretinoin; Vascular Cell Adhesion Molecule-1

Pulmonary hypoplasia (PH), characterized by alveolar immaturity, is one of the leading causes of respiratory insufficiency in newborns with congenital diaphragmatic hernia (CDH). Leptin (Lep) and its receptor (Lep-R) play an important role in fetal lung growth by stimulating alveolar differentiation and maturation. Lep and Lep-R are strongly expressed by alveolar cells during the saccular stage of fetal lung development. Lep-deficient mice exhibit decreased alveolarization with reduced pulmonary surfactant phospholipid synthesis, similar to human and nitrofen-induced PH. Prenatal administration of all-trans retinoic acid (ATRA) has been shown to stimulate alveolarization in nitrofen-induced PH. Recent studies have demonstrated that Lep and Lep-R expression in developing lungs is regulated by ATRA. We hypothesized that prenatal treatment with ATRA increases pulmonary Lep and Lep-R expression in the nitrofen model of CDH-associated PH.. Time-mated rats received either 100 mg nitrofen or vehicle via oral-gastric lavage on embryonic day 9.5 (E9.5). Control and nitrofen-exposed dams were randomly assigned to either intraperitoneal ATRA (5 mg/kg/d) or placebo administration on E18.5, E19.5 and E20.5. Fetal lungs were harvested on E21.5, and divided into Control+Placebo, Control+ATRA, Nitrofen+Placebo and Nitrofen+ATRA. Alveolarization was assessed using stereo- and morphometric analysis techniques. Surfactant phospholipid synthesis was analyzed by labeling for surfactant protein B (SP-B). Pulmonary gene expression levels of Lep and Lep-R were determined using quantitative real-time polymerase chain reaction. Immunohistochemical staining for Lep and Lep-R was performed to evaluate alveolar protein expression and localization.. In vivo administration of ATRA resulted in significantly increased lung-to-body weight ratio with enhanced radial alveolar count and decreased mean linear intercept compared to placebo treatment. Immunofluorescence analysis demonstrated markedly increased pulmonary SP-B expression in Nitrofen+ATRA compared to Nitrofen+Placebo. Relative mRNA expression of Lep and Lep-R was significantly increased in Nitrofen+ATRA compared to Nitrofen+Placebo. Lep and Lep-R immunoreactivity was markedly increased in interstitial and alveolar epithelial cells of Nitrofen+ATRA compared to Nitrofen+Placebo.. Increased Lep and Lep-R expression after prenatal administration of ATRA in nitrofen-induced PH suggests that ATRA may have therapeutic potential in attenuating CDH-associated PH by stimulating alveolarization and de novo surfactant production.

Topics: Animals; Disease Models, Animal; Female; Hernias, Diaphragmatic, Congenital; Immunohistochemistry; Leptin; Lung; Organogenesis; Pregnancy; Pregnancy, Animal; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Tretinoin; Up-Regulation

The study was designed to better understand how retinoic acid (RA) influenced the migration and invasion abilities of retinal pigment epithelial cells (RPE) in vitro and how the related genes of the extracellular matrix (ECM) were expressed. The inhibition effects of RA on proliferative vitreoretinopathy (PVR) formation induced by RPE cells were studied in rabbits. Wound healing and Boyden chamber assays were used to show the abilities of migration and invasion of RPE. Microarray, real-time quantitative PCR (qPCR) and Western blotting showed how RA regulated the ECM genes. RA (10(-5) M) significantly (P < 0.05) inhibited PVR membrane and traction retinal detachment formation (80%). Moreover, RA treatment significantly inhibited the migration (80%) and invasion (65%) behaviors of human RPE cells (P < 0.05) by wound healing and Boyden chamber assays, respectively. Microarray and q PCR analysis showed RA treatment did inhibit the motility of human RPE cells by inhibition of metalloproteinases (MMP) 1, 2, 9, fibronectin-1, transforming growth factor beta, thrombospondin-1, tenascin C, most collagen, integrin, laminin molecules and along enhancing E-cadherin and MMP3 genes expression. And Western blotting indicated the coincident results on protein level of MMP1, 2, 3, 9, 14; fibronectin-1; integrinαM, β2 and E-cadherin. In conclusions, RA is a vital drug to inhibit the abilities of migration and invasion of RPE and to hamper the PVR formation by regulating some genes expression of ECM.

Topics: Adult; Animals; Antineoplastic Agents; Cell Adhesion; Cell Adhesion Molecules; Cell Movement; Cells, Cultured; Cytoskeleton; Disease Models, Animal; Extracellular Matrix; Extracellular Matrix Proteins; Gene Expression; Humans; Oligonucleotide Array Sequence Analysis; Rabbits; Retinal Pigment Epithelium; RNA, Messenger; Tretinoin; Vitreoretinopathy, Proliferative; Wound Healing

Stra6 is the retinoic acid (RA)-inducible gene encoding the cellular receptor for holo-retinol binding protein. This transmembrane protein mediates the internalization of retinol, which then upregulates RA-responsive genes in target cells. Here, we show that Stra6 can be upregulated by DNA damage in a p53-dependent manner, and it has an important role in cell death responses. Stra6 expression induced significant amounts of apoptosis in normal and cancer cells, and it was also able to influence p53-mediated cell fate decisions by turning an initial arrest response into cell death. Moreover, inhibition of Stra6 severely compromised p53-induced apoptosis. We also found that Stra6 induced mitochondria depolarization and accumulation of reactive oxygen species, and that it was present not only at the cellular membrane but also in the cytosol. Finally, we show that these novel functions of Stra6 did not require downstream activation of RA signalling. Our results present a previously unknown link between the RA and p53 pathways and provide a rationale to use retinoids to upregulate Stra6, and thus enhance the tumour suppressor functions of p53. This may have implications for the role of vitamin A metabolites in cancer prevention and treatment.

Topics: Animals; Apoptosis; Base Sequence; Cell Line, Tumor; Cells, Cultured; Colorectal Neoplasms; Disease Models, Animal; DNA Damage; Fibroblasts; Humans; Membrane Proteins; Mice; Mice, Knockout; Molecular Sequence Data; Reactive Oxygen Species; Signal Transduction; Tretinoin; Tumor Suppressor Protein p53; Urinary Bladder Neoplasms

We determined the mechanism by which all-trans retinoic acid (ATRA) inhibits experimental autoimmune uveitis (EAU) and determined the role of γδ T cells in this autoimmune disease.. C57BL/6 (B6) mice were immunized with the uveitogenic, interphotoreceptor retinoid-binding protein1-20 peptide (IRBP1-20) in complete Freund's adjuvant (CFA), with or without a preceding ATRA treatment. Responses and pathogenic activity of Th1- and Th17-autoreactive T cells were compared, and the effects of ATRA on γδ T cells and CD25(+) dendritic cell (DC) subset were determined. Interactions among uveitogenic T cells, DC subsets, and γδ T cells were investigated.. Administration of ATRA to B6 mice in which EAU was induced suppressed the response of Th17 autoreactive T cells, which was associated with decreased generation of the CD25(+) DC subset and suppressed activation of γδ T cells. Adoptively transferred γδ T cells isolated from ATRA-treated mice showed a diminished ability to promote the activation of Th17 autoreactive T cells in vitro and in vivo compared to γδ T cells from untreated donors.. ATRA inhibits the expansion of CD25(+) DCs and γδ T-cell activation, thereby restraining the Th17 autoreactive T-cell response.

Topics: Animals; Antineoplastic Agents; Autoimmune Diseases; Cell Differentiation; Dendritic Cells; Disease Models, Animal; Interleukin-17; Interleukin-2 Receptor alpha Subunit; Mice; Mice, Inbred C57BL; Receptors, Antigen, T-Cell, gamma-delta; Th17 Cells; Tretinoin; Uveitis

Ischemia/reperfusion-induced intestinal injury is mediated by reactive oxygen species and inflammatory mediators.. This study was designed to evaluate whether all-trans-retinoic acid (ATRA) administration can attenuate intestinal injury and to analyze the antioxidant and anti-inflammatory effects of ATRA in a neonatal rat model of necrotizing enterocolitis (NEC).. Twenty-nine Wistar albino rat pups were randomly divided into 3 groups: group 1 = control, group 2 = NEC and saline, and group 3 = NEC and ATRA treatment. NEC was induced by hyperosmolar enteral formula feeding and exposure to hypoxia after cold stress at +4°C and oxygen. Pups in group 3 were injected intraperitoneally with ATRA (0.5 mg/kg body weight) once a day prior to each NEC procedure, beginning on postnatal day 1 and daily through postnatal day 4. The pups were killed on the 4th day and their intestinal tissues were harvested for biochemical and histopathological analysis.. Mucosal injury scores and intestinal malondialdehyde levels in group 2 were found to be significantly higher than other groups (p < 0.05). Intestinal superoxide dismutase and glutathione peroxidase activities in group 3 were significantly higher than group 2 (p = 0.04 and p = 0.04, respectively). Intestinal tissue tumor necrosis factor-α levels were significantly reduced with ATRA treatment in group 3 compared to group 2 (p < 0.001).. It is likely that oxidative stress and inflammatory mediators contributed to the pathogenesis of NEC and that ATRA had a protective effect on intestinal injury through its anti-inflammatory and antioxidant properties.

Topics: Animals; Animals, Newborn; Anti-Inflammatory Agents; Antioxidants; Cold Temperature; Disease Models, Animal; Enterocolitis, Necrotizing; Glutathione Peroxidase; Hypertonic Solutions; Hypoxia; Injections, Intraperitoneal; Intestinal Mucosa; Intestines; Malondialdehyde; Oxidative Stress; Rats; Rats, Wistar; Superoxide Dismutase; Tretinoin; Tumor Necrosis Factor-alpha

Precise tissue concentration of retinoic acid (RA) is indispensable for proper interaction of second heart field cells with cardiac neural crest cells and induction of signalling pathways important for normal myocardial growth.. Since RA deficiency during embryogenesis induces noncompaction, we hypothesised that excess RA at the stage of heart tube elongation may cause thinning of the myocardial wall which leads to noncompaction.. RA was administered at 70 mg/kg b.w. on 8.5 days post coitus (dpc) to pregnant mice to elicit cardiac malformations in foetuses. We studied noncompaction development in RA-treated mouse offspring. The cardiac noncompaction was evaluated in different stages of heart development as the quotient of the distance between the epicardial surface and trabecular tips(represented by a) and the distance between the epicardial surface and trabecular recesses (represented by b) in RA-treated hearts compared to control non-treated.. We demonstrated that apart from outflow tract defects such as double outlet right ventricle, transposition of the great arteries and tetralogy of Fallot in foetuses in mouse offspring, noncompaction occurs in about 42% of cases. At the stage of 13 dpc and later in development the ratio a/b was higher in RA-treated hearts exhibiting noncompaction compared to the control hearts. This cardiomyopathy was more evident in the right ventricle than in the left ventricle.. Noncompaction caused by RA overdose can be elicited in part of the mouse offspring by administering RA at the stage of cardiac tube elongation.

Topics: Animals; Disease Models, Animal; Drug Overdose; Female; Heart; Heart Defects, Congenital; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Myocardium; Pregnancy; Prenatal Exposure Delayed Effects; Tomography, X-Ray Computed; Tretinoin

All-trans retinoic acid (ATRA) is reported to reduce hair cell loss and hearing deterioration caused by noise-induced hearing loss (NIHL). The present study investigates the involvement of peroxiredoxin 6 (Prdx 6) in ATRA-mediated protection of temporary threshold shift of hearing. Mice fed with ATRA before or after exposure to white noise showed a faster recovery than untreated controls within 1 week, with a concomitant increase of cochlear Prdx 6 expression. Treatment of mouse auditory cells with ATRA induced Prdx 6 expression. A putative retinoic acid (RA)-response element (RARE) was identified in a murine Prdx 6 promoter region. Prdx 6 promoter activities were elevated in wild-type reporter plasmid-transfected cells, whereas no significant change in activity was in those with RARE-disrupted mutant reporter. RA receptor α (RARα) functions as a transactivator of Prdx 6 gene expression. These findings suggest that ATRA-induced Prdx 6 expression may be associated with rapid recovery from temporary NIHL.

Topics: Animals; Auditory Fatigue; Binding Sites; Cell Line; Cochlea; Disease Models, Animal; Dose-Response Relationship, Drug; Hearing; Hearing Loss, Noise-Induced; Mice; Mice, Inbred BALB C; Mutation; Peroxiredoxin VI; Promoter Regions, Genetic; Receptors, Retinoic Acid; Recovery of Function; Response Elements; Retinoic Acid Receptor alpha; Signal Transduction; Time Factors; Transcriptional Activation; Transfection; Tretinoin; Up-Regulation

Airway inflammation is mainly mediated by T helper 2 cells (Th2) that characteristically produce interleukin (IL)-4, IL-5, and IL-13. Epidemiological studies have revealed an inverse association between the dietary intake of vitamin A and the occurrence of asthma. Serum vitamin A concentrations are significantly lower in asthmatic subjects than in healthy control subjects. It has been reported that all-trans retinoic acid (ATRA), a potent derivative of vitamin A, regulates immune responses. However, its role in Th2-mediated airway inflammation remains unclear. We investigated the effects of ATRA in a mouse model of allergic airway inflammation.. We found that ATRA treatment attenuated airway inflammation and decreased mRNA levels of Th2- and Th17-related transcription factors. The data showed that airway inflammation coincided with levels of Th2- and Th17-related cytokines. We also showed that ATRA inhibited Th17 and promoted inducible regulatory T-cell differentiation, whereas it did not induce an obvious effect on Th2 differentiation in vitro. Our data suggest that ATRA may interfere with the in vivo Th2 responses via T-cell extrinsic mechanisms.. Administration of ATRA dramatically attenuated airway inflammation by inhibiting Th2 and Th17 differentiation and/or functions. ATRA may have potential therapeutic effects for airway inflammation in asthmatic patients.

Topics: Animals; Antigens; Asthma; Cell Differentiation; Cytokines; Disease Models, Animal; Down-Regulation; Female; Forkhead Transcription Factors; Inflammation; Lung; Lymph Nodes; Mice; Mice, Inbred BALB C; Spleen; Th17 Cells; Th2 Cells; Transcription Factors; Tretinoin

Zebrafish embryos have been widely used to study the genes and processes needed for normal vertebrate heart development. We recently observed that exposure to 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD) or retinoic acid (RA) produces very similar signs of heart failure in developing zebrafish via divergent molecular pathways. The fact that diverse stressors and mutations cause severe pericardial edema and circulatory collapse in developing zebrafish has been largely unexplored. We hypothesized that unrelated chemicals can trigger a common pathological response leading to the same end-stage heart failure. To test this hypothesis, we compared the effects of TCDD, RA, carbaryl, valproic acid, and morpholino oligonucleotide (MO) knockdown of TBX5 on the developing heart in zebrafish embryos. These model stressors have all been previously reported to affect zebrafish heart development, and elicited very similar signs of embryonic heart failure. Microarray analysis showed that one cluster of 92 transcripts affected by these different treatments was significantly downregulated by all treatments. This gene cluster is composed of transcripts required for chromosome assembly, DNA replication, and cell cycle progression. We refer to this cluster as the cell cycle gene cluster (CCGC). Immunohistochemistry revealed that downregulation of the CCGC precedes a halt in cardiomyocyte proliferation in the hearts of zebrafish exposed to any of the treatments. Previous work has shown that the initial response to TCDD is a decrease in cardiac output. Since this precedes the signs of edema, heart failure, and fall in CCGC expression, we postulated that any factor that decreases cardiac output will produce the same syndrome of heart failure responses. To test this, we used MO knockdown of cardiac troponin T2 (TNNT2) to specifically block contractility. The TNNT2-MO produced exactly the same signs of cardiotoxicity as the other treatments, including downregulation of the signature CCGC. Our results indicate that agents altering cardiac output can have amplified consequences during specific periods in development.

Topics: Animals; Carbaryl; Cell Proliferation; Disease Models, Animal; Edema, Cardiac; Embryo, Nonmammalian; Gene Expression; Genes, cdc; Heart; Heart Failure; Morpholinos; Myocardial Contraction; Myocardium; Phenotype; Polychlorinated Dibenzodioxins; Tretinoin; Valproic Acid; Zebrafish

We investigated the effect of β-carotene (bC) supplementation during pregnancy in a mouse model of severe vitamin A deficiency, i.e. Lrat-/-Rbp-/- dams maintained on a vitamin A-deficient diet during gestation. bC, a provitamin A carotenoid, can be enzymatically cleaved to form vitamin A for use by the developing embryo. We found that an acute supplementation (13.5 days post coitum, dpc) of bC to Lrat-/-Rbp-/- dams on a vitamin A-deficient diet activated transcriptional mechanisms in the developing tissues to maximize the utilization of bC provided to the dams. Nevertheless, these regulatory mechanisms are inefficient under this regimen, as the embryonic phenotype was not improved. We further investigated the effect of a repeated supplementation of bC during a crucial developmental period (6.5-9.5 dpc) on the above-mentioned mouse model. This treatment improved the embryonic abnormalities, as 40% of the embryos showed a normal phenotype. In addition, analysis of retinoic acid-responsive genes, such as Cyp26a1 in these embryos suggests that bC cleavage results in the production of retinoic acid which then can be used by the embryo. Taken together, these in vivo studies show that bC can be used as a source of vitamin A for severely vitamin A-deficient mammalian embryos.

Topics: Animals; beta Carotene; Cytochrome P-450 Enzyme System; Disease Models, Animal; Female; Gene Expression Regulation, Developmental; Maternal-Fetal Exchange; Mice; Phenotype; Pregnancy; Retinoic Acid 4-Hydroxylase; Retinoids; Severity of Illness Index; Tretinoin; Vitamin A Deficiency

The authors undertook this study to assess the effect of preterm delivery with respect to neural protection in a congenital myelomeningocele (MMC) mouse model.. After confirmation of pregnancy in 15 female mice, a congenital MMC model was produced by administration of retinoic acid on the 7th day of gestation. The pregnant mice underwent cesarean sections on Days 15 (n = 5, Group E15), 17 (n = 5, Group E17), and 19 (n = 5, Group E19). Histological analyses were conducted on the lumbar defect and on the craniocervical junction in all fetuses with MMC.. Fetuses in Group E19 showed the most significant injury to neural tissue of the spinal cord at the MMC area followed by those in Group E17, with Group E15 being the least affected. All groups exhibited a degree of Chiari malformation; Group E19 was the most affected, followed by Group E17, and Group E15 was the least affected.. Development of both Chiari malformation and exposed spinal cord injury are progressive during gestation. Preterm delivery in this mouse model of congenital MMC may minimize the degree of injury to the spinal cord neural tissue and the degree of Chiari malformation.

Topics: Animals; Arnold-Chiari Malformation; Cesarean Section; Disease Models, Animal; Female; Gestational Age; Meningomyelocele; Mice; Pregnancy; Premature Birth; Spinal Cord; Time Factors; Tretinoin

The blood testis-barrier (BTB) is essential for maintaining homeostasis in the seminiferous epithelium. Although many studies have reported that vitamin A (VA) is required for the maintenance of spermatogenesis, the relationships between the BTB, spermatogenesis and VA have not been elucidated. In this study, we analyzed BTB assembly and spermatogenesis in the testes of mice fed the VA-deficient (VAD) diet from the prepubertal period to adulthood. During the prepubertal period, no changes were observed in the initiation and progression of the first spermatogenic wave in mice fed the VAD diet. However, the numbers of preleptotene/leptotene spermatocytes derived from the second spermatogenic wave onwards were decreased, and initial BTB formation was also delayed, as evidenced by the decreased expression of mRNAs encoding BTB components and VA signaling molecules. From 60 days postpartum, mice fed the VAD diet exhibited apoptosis of germ cells, arrest of meiosis, disruption of the BTB, and dramatically decreased testis size. Furthermore, vacuolization and calcification were observed in the seminiferous epithelium of adult mice fed the VAD diet. Re-initiation of spermatogenesis by VA replenishment in adult mice fed the VAD diet rescued BTB assembly after when the second spermatogenic wave initiated from the arrested spermatogonia reached the preleptotene/leptotene spermatocytes. These results suggested that BTB integrity was regulated by VA metabolism with meiotic progression and that the impermeable BTB was required for persistent spermatogenesis rather than meiotic initiation. In conclusion, consumption of the VAD diet led to critical defects in spermatogenesis progression and altered the dynamics of BTB assembly.

Topics: Animals; Apoptosis; Biomarkers; Blood-Testis Barrier; Calcinosis; Diet; Disease Models, Animal; Epididymis; Female; Gene Expression Regulation, Developmental; Infertility, Male; Male; Metaplasia; Mice; Mice, Inbred C57BL; Organ Size; Spermatogenesis; Spermatogonia; Testis; Tretinoin; Vacuoles; Vitamin A Deficiency

The transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway has a central role in pathogenesis of lung fibrosis. In the present study, we investigated if all-trans retinoic acid (ATRA) could attenuate fibrosis in bleomycin (BLM)-induced lung fibrosis in rats through regulating TGF-β1/Smad3 signaling. Beginning on day 14 after BLM administration, the ATRA I and II groups of rats received daily oral administration of ATRA for 14 days. All rats were killed on day 28. Lung tissue sections were prepared and subject to histological assessment, and expression levels of proteins involved in the TGF-β1 signaling cascade and epithelial-mesenchymal transition (EMT) were evaluated by transmission electron microscopy (TEM), quantitative real-time polymerase chain reaction (qRT-PCR), western blot procedure, and immunohistochemical or immunofluorescence staining. BLM significantly increased the alveolar septum infiltrates, inflammatory cell infiltrates, and collagen fibers. These BLM-induced changes were significantly ameliorated by ATRA treatment. In addition, BLM significantly increased levels of lung fibrosis markers α-SMA, hydroxyproline (Hyp), collagen I, Snail, and Twist, whereas significantly decreased E-cadherin expression. ATRA treatment largely reversed BLM-induced changes in these lung fibrosis markers. ATRA also blocked BLM-induced activation of the TGF-β1/Smad3 signaling pathway in lung tissues, including expression of TGF-β1, Smad3, p-Smad3, zinc-finger E-box-binding homeobox 1 and 2 (ZEB1 and ZEB2), and the high-mobility group AT-hook 2 (HMGA2). Our results suggest that ATRA may have potential therapeutic value for lung fibrosis treatment.

Topics: Animals; Biomarkers; Bleomycin; Collagen; Disease Models, Animal; Down-Regulation; Epithelial-Mesenchymal Transition; HMGA2 Protein; Homeodomain Proteins; Pulmonary Fibrosis; Rats; Rats, Sprague-Dawley; RNA, Messenger; Signal Transduction; Smad3 Protein; Transcription Factors; Transforming Growth Factor beta1; Tretinoin; Zinc Finger E-box-Binding Homeobox 1

Aberrant histone acetylation plays an essential role in the neoplastic process via the epigenetic silencing of tumour suppressor genes (TSGs); therefore, the inhibition of histone deacetylases (HDAC) has become a promising target in cancer therapeutics. To investigate the correlation of histone acetylation with clinicopathological features and TSG expression, we examined the expression of acetylated H3 (AcH3), RARβ2, E-cadherin, and β-catenin by immunohistochemistry in 65 cervical squamous cell carcinoma patients. The results revealed that the absence of AcH3 was directly associated with poor histological differentiation and nodal metastasis as well as reduced/negative expression of RARβ2, E-cadherin, and β-catenin in clinical tumour samples. We further demonstrated that the clinically available HDAC inhibitors valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA), in combination with all-trans retinoic acid (ATRA), can overcome the epigenetic barriers to transcription of RARβ2 in human cervical cancer cells. Chromatin immunoprecipitation analysis showed that the combination treatment increased the enrichment of acetylated histone in the RARβ2-RARE promoter region. In view of these findings, we evaluated the antitumor effects induced by combined VPA and ATRA treatment in a xenograft model implanted with poorly differentiated human squamous cell carcinoma. Notably, VPA restored RARβ2 expression via epigenetic modulation. Additive antitumour effects were produced in tumour xenografts by combining VPA with ATRA treatment. Mechanistically, the combination treatment reactivated the expression of TSGs RARβ2, E-cadherin, P21 (CIP1) , and P53 and reduced the level of p-Stat3. Sequentially, upregulation of involucrin and loricrin, which indicate terminal differentiation, strongly contributed to tumour growth inhibition along with partial apoptosis. In conclusion, targeted therapy with HDAC inhibitors and RARβ2 agonists may represent a novel therapeutic approach for patients with cervical squamous cell carcinoma.

Topics: Animals; Antineoplastic Agents; beta Catenin; Cadherins; Carcinoma, Squamous Cell; Cell Line, Tumor; Disease Models, Animal; Epigenesis, Genetic; Female; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Humans; Promoter Regions, Genetic; Protein Binding; Retinoid X Receptor beta; Transcriptional Activation; Tretinoin; Tumor Burden; Tumor Suppressor Proteins; Uterine Cervical Neoplasms; Valproic Acid; Xenograft Model Antitumor Assays

Blood vessels are necessary for development and maintenance of the endometriosis and blood flow supplies oxygen and essential nutrient to the disease. Local angiogenesis is regulated by vascular endothelial growth factor (VEGF) and inhibitors of VEGF may be a novel therapeutic approach. We inducted endometriosis in 43 rats and they were randomly allocated into 4 groups. The rats in group I (control n = 11) were given no medication. The rats in group II (n = 11) were given bevacizumab. The rats in group III (n = 11) were given Sorafenib, and the rats in group IV (n = 10) were given retinoic acid (RA). Then groups were compared for microvessel density, VEGF, soluble tyrosine-kinase receptor, ovarian reserve, and treatment effectivity. All these medications were effective on endometriosis and we detected that volume of endometriotic implants were significantly decreased. Ovarian reserve was not affected from the medication, in addition RA have induced reproductive capacity.

Topics: Administration, Oral; Animals; Antibodies, Monoclonal, Humanized; Bevacizumab; Disease Models, Animal; Endometriosis; Female; Microvessels; Niacinamide; Phenylurea Compounds; Random Allocation; Rats; Rats, Wistar; Sorafenib; Treatment Outcome; Tretinoin

Recent studies have revealed that aberrant vitamin A signaling may lead to memory deficits in rodents. Present study investigates the potential of all-trans-retinoic acid (ATRA) an agonist at retinoid acid family of receptors, in cognitive dysfunctions associated with experimental dementia. Streptozotocin (STZ) [3 mg/kg, intracerebroventricularly (i.c.v)] was administered on alternate days (day 1 and day 3) to induce dementia in Swiss albino mice. STZ mice were administered ATRA (10 mg/kg; 20 mg/kg, p.o.) for a total of 19 days following second i.c.v injection of STZ [day 4 to day 22]. Morris water maze (MWM) test was performed on days 19, 20, 21, 22 and 23 to assess learning and memory of the animals. Following MWM test, the animals were sacrificed for biochemical and histopathological studies. Extent of oxidative stress was measured by estimating the levels of brain reduced glutathione (GSH) and thiobarbituric acid reactive species (TBARS). Brain acetylcholinestrase (AChE) activity and serum cholesterol levels were also estimated. The brain level of myeloperoxidase (MPO) was measured as a marker of inflammation. STZ produced a marked decline in MWM performance of the animals, reflecting impairment of learning and memory. STZ treated mice showed marked accentuation of AChE activity, TBARS and MPO levels along with fall in GSH level. Further the stained micrographs of STZ-treated mice indicated pathological changes, severe neutrophilic infiltration and amyloid deposition. ATRA treatment significantly attenuated STZ-induced memory deficits, biochemical and histopathological alterations. The findings demonstrate that the memory restorative ability of ATRA may be attributed to its anti-cholinesterase, anti-oxidative and anti-inflammatory potential.

Topics: Alzheimer Disease; Animals; Brain; Dementia; Disease Models, Animal; Female; Glutathione; Male; Maze Learning; Memory Disorders; Mice; Peroxidase; Reactive Oxygen Species; Streptozocin; Thiobarbiturates; Tretinoin

Neurogenesis is regulated by a number of signaling pathways, including the retinoic acid (RA) pathway, a key regulator of neurogenesis in the subventricular zone (SVZ) and hippocampus. Acupuncture has been used to treat neurological conditions and is known to potentially enhance cell proliferation in the neurogenic area (hippocampal dentate gyrus and the SVZ of the lateral ventricle walls) in pathological conditions, which is associated with improved brain function. However, whether or not the neuroprotective effects of electroacupuncture (EA) are mediated by the regulation of the RA signaling pathway remains to be determined. Using a transient middle cerebral artery occlusion model, in the present study we evaluated the effect of EA on the neurological functional recovery, infarction volume and investigated the underlying molecular mechanisms. Two hundred and sixteen SD rats were randomly divided into 3 groups: sham, model group (ischemic rats without EA stimulation) and EA group (ischemic rats with EA stimulation on ST36 and LI11). Behavioral deficits were detected with high-resolution digital analysis of 24-h home-cage video recordings. Infarct volume was determined by triphenyltetrazolium hydrochloride staining and the expression of RA mRNA and protein was measured using RT-PCR and western blotting, respectively. We found that EA decreased the infarct volume, promoted neurological functional recovery and increased the RA mRNA and protein expression, compared with the model group. Findings of this study suggest that promoting neurological functional recovery by modulating RA expression in the post-ischemic brain is one of the mechanisms by which EA can be effective in the treatment of ischemic stroke.

Topics: Animals; Brain; Brain Ischemia; Cell Proliferation; Disease Models, Animal; Electroacupuncture; Hippocampus; Infarction, Middle Cerebral Artery; Lateral Ventricles; Male; Neurogenesis; Rats; Rats, Sprague-Dawley; Recovery of Function; Reperfusion Injury; Signal Transduction; Stroke; Tetrazolium Salts; Tretinoin

All-trans retinoic acid (ATRA) is an important therapeutic agent for prevention of the renal diseases. Transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway is a key signaling pathway which takes part in the progression of renal interstitial fibrosis (RIF). This investigation was performed to study the effect of ATRA in RIF rats and its effect on the TGF-β1/Smad3 signaling pathway. Sixty Wistar male rats were divided into three groups at random: sham operation group (SHO), model group subjected to unilateral ureteral obstruction (GU), model group treated with ATRA (GA), n = 20, respectively. RIF index, protein expression of TGF-β1, collagen-IV (Col-IV) and fibronectin (FN) in renal interstitium, and mRNA and protein expressions of Smad3 in renal tissue were detected at 14-day and 28-day after surgery. The RIF index was markedly elevated in group GU than in SHO group (p < 0.01), and the RIF index of GA group was alleviated when compared with that in GU group (p < 0.01). Compared with in group SHO, the mRNA/protein expression of Smad3 in renal tissue was significantly increased in group GU (p < 0.01). However, the mRNA and protein expressions of Smad3 in renal tissue in GA group were not markedly alleviated by ATRA treatment when compared with those in GU (each p > 0.05). Protein expressions of TGF-β1, Col-IV, and FN in GU group were markedly increased than those in SHO group (each p < 0.01), and their expressions in GA group were markedly down-regulated by ATRA treatment than those of GU group (all p < 0.01). The protein expression of Smad3 was positively correlated with RIF index, protein expression of TGF-β1, Col-IV or FN (each p < 0.01). In conclusion, ATRA treatment can alleviate the RIF progression in UUO rats. However, ATRA cannot affect the signaling pathway of TGF-β1/Smad3 in the progression of RIF.

Topics: Analysis of Variance; Animals; Biopsy, Needle; Blotting, Western; Disease Models, Animal; Disease Progression; Down-Regulation; Fibrosis; Gene Expression Regulation; Immunohistochemistry; Male; Nephritis, Interstitial; Random Allocation; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Reference Values; Risk Factors; Signal Transduction; Smad3 Protein; Statistics, Nonparametric; Transforming Growth Factor beta1; Treatment Outcome; Tretinoin

Calcific aortic valve disease (CAVD) is a major public health problem with no effective treatment available other than surgery. We previously showed that mature heart valves calcify in response to retinoic acid (RA) treatment through downregulation of the SRY transcription factor Sox9. In this study, we investigated the effects of excess vitamin A and its metabolite RA on heart valve structure and function in vivo and examined the molecular mechanisms of RA signaling during the calcification process in vitro.. Using a combination of approaches, we defined calcific aortic valve disease pathogenesis in mice fed 200 IU/g and 20 IU/g of retinyl palmitate for 12 months at molecular, cellular, and functional levels. We show that mice fed excess vitamin A develop aortic valve stenosis and leaflet calcification associated with increased expression of osteogenic genes and decreased expression of cartilaginous markers. Using a pharmacological approach, we show that RA-mediated Sox9 repression and calcification is regulated by classical RA signaling and requires both RA and retinoid X receptors.. Our studies demonstrate that excess vitamin A dietary intake promotes heart valve calcification in vivo. Therefore suggesting that hypervitaminosis A could serve as a new risk factor of calcific aortic valve disease in the human population.

Topics: Animals; Aortic Valve; Calcinosis; Cell Line; Chick Embryo; Collagen Type II; Dietary Supplements; Disease Models, Animal; Diterpenes; Gene Expression Profiling; Gene Expression Regulation; Heart Valve Diseases; Hypervitaminosis A; Mice; Mice, Inbred C57BL; Oligonucleotide Array Sequence Analysis; Osteogenesis; Osteopontin; Receptors, Retinoic Acid; Retinoid X Receptors; Retinyl Esters; RNA Interference; Signal Transduction; SOX9 Transcription Factor; Time Factors; Tissue Culture Techniques; Transfection; Tretinoin; Vitamin A; Vitamins

Topics: Animals; Antibodies, Monoclonal, Humanized; Disease Models, Animal; Endometriosis; Female; Niacinamide; Phenylurea Compounds; Tretinoin

Retinoic acid (RA) may promote survival or apoptosis of cells, depending on the levels of binding proteins: apoptosis-inducing cellular RA binding protein 2 (CRABP2), and cell survival-promoting fatty acid binding protein 5 (FABP5). Increased cellular uptake of retinol and altered actions of RA related to reduced expression of CRABP2 may contribute to the development of endometriosis. Recently statins have been shown to inhibit growth of human endometrial stromal (HES) cells and to reduce the number and size of endometriotic implants in experimental models of this disorder.. The objective of the study was to determine whether effects of simvastatin on HES cells and experimental endometriotic implants are related to the modulation of the RA system.. Effects of simvastatin and RA on proliferation and apoptosis of HES cells were evaluated. Expression of stimulated by RA 6 (STRA6), CRABP2, and FABP5 was determined by real-time PCR and Western blotting. Effects of simvastatin were also evaluated in a nude mouse model of human endometriosis.. Simvastatin potentiated an inhibitory effect of RA on growth of HES cells. In HES cells, simvastatin induced expression of STRA6 and CRABP2 but not FABP5. Similarly, simvastatin treatment of nude mice bearing human endometrial xenografts led to an increased expression of CRABP2 and STRA6 proteins in ectopic lesions.. Simvastatin interacts with the RA system, inducing the expression of the key protein regulating the uptake of retinol (STRA6) and the expression of apoptosis-promoting CRABP2. These effects may contribute to cooperative apoptosis-inducing effects of simvastatin and RA and support the examination of these compounds in the treatment of endometriosis.

Topics: Adult; Animals; Apoptosis; Cell Proliferation; Cell Survival; Chimera; Disease Models, Animal; Endometriosis; Endometrium; Fatty Acid-Binding Proteins; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Membrane Proteins; Mice; Mice, Nude; Neoplasm Proteins; Primary Cell Culture; Receptors, Retinoic Acid; Simvastatin; Stromal Cells; Tretinoin

Homozygous null mutation of fibroblast growth factor receptor 2 (Fgfr2IIIb) or its ligand fibroblast growth factor 10 (Fgf10) results in duodenal atresia in mice. Mutations of either of these genes in humans cause Matthew-Wood syndrome and associated duodenal stenosis. Recently, mutations in the retinol-binding protein receptor gene STRA6 were reported to be implicated in this syndrome as well. This suggests that the retinoic acid (RA) signaling pathway interacts with the Fgf10-Fgfr2IIIb signaling pathway during duodenal development. Accordingly, we hypothesized that Fgfr2IIIb-/- mouse embryos would exhibit disruptions in expression of Raldh2, the gene for the enzyme that regulates the final step in the conversion of vitamin A to the active form RA, during duodenal atresia formation.. Fgfr2III -/- mice were generated from heterozygous breedings. Embryos were harvested between embryonic day (E) 11.0 to E 13.5 and genotyped by polymerase chain reaction (PCR). Duodenums were dissected out, fixed and photographed. Whole mount and section in situs were performed for Raldh2.. Fgfr2IIIb-/- embryos demonstrate subtle changes in the duodenal morphology by E11.5 with complete involution of the atretic precursor by E 13.5. Raldh2 appears to be down-regulated as early as E 11.5 in the atretic precursor a full 2 days before this segment disappears.. In Fgfr2IIIb-/- mouse embryos, a reduction of Raldh2 expression is observed within the region that is forming the atresia. This is the first demonstration of such an event in this model. As in humans, these results implicate disruptions between Fgfr2IIIb receptor function and RA signaling in the formation of this defect and indicate that Fgfr2IIIb-/- mouse embryos are a valid model for the study of the atretic spectrum of defects in human duodenal development.

Topics: Aldehyde Oxidoreductases; Animals; Disease Models, Animal; Down-Regulation; Duodenal Obstruction; Duodenum; Intestinal Atresia; Mice; Mice, Inbred Strains; Receptor, Fibroblast Growth Factor, Type 2; Sequence Deletion; Signal Transduction; Tretinoin; Vitamin A

The vitamin E derivative (+)α-tocopheryl succinate (α-TOS) exerts pro-apoptotic effects in a wide range of tumors and is well tolerated by normal tissues. Previous studies point to a mitochondrial involvement in the action mechanism; however, the early steps have not been fully elucidated. In a model of acute promyelocytic leukemia (APL) derived from hCG-PML-RARα transgenic mice, we demonstrated that α-TOS is as effective as arsenic trioxide or all-trans retinoic acid, the current gold standards of therapy. We also demonstrated that α-TOS induces an early dissipation of the mitochondrial membrane potential in APL cells and studies with isolated mitochondria revealed that this action may result from the inhibition of mitochondrial respiratory chain complex I. Moreover, α-TOS promoted accumulation of reactive oxygen species hours before mitochondrial cytochrome c release and caspases activation. Therefore, an in vivo antileukemic action and a novel mitochondrial target were revealed for α-TOS, as well as mitochondrial respiratory complex I was highlighted as potential target for anticancer therapy.

Topics: alpha-Tocopherol; Animals; Antineoplastic Agents; Antioxidants; Apoptosis; Arsenic Trioxide; Arsenicals; Caspases; Cell Line, Tumor; Cytochromes c; Disease Models, Animal; Electron Transport Complex I; Electron Transport Complex II; Humans; Leukemia, Promyelocytic, Acute; Membrane Potential, Mitochondrial; Mice; Mice, Transgenic; Mitochondria; Neoplastic Stem Cells; Oncogene Proteins, Fusion; Oxides; Protein Stability; Rats; Reactive Oxygen Species; Transplantation, Isogeneic; Tretinoin

Anomalous neuritogenesis is a hallmark of neurodegenerative disorders, including retinal degenerations, epilepsy, and Alzheimer's disease. The neuritogenesis processes result in a partial reinnervation, new circuitry, and functional changes within the deafferented retina and brain regions. Using the light-induced retinal degeneration (LIRD) mouse model, which provides a unique platform for exploring the mechanisms underlying neuritogenesis, we found that retinoid X receptors (RXRs) control neuritogenesis. LIRD rapidly triggered retinal neuron neuritogenesis and up-regulated several key elements of retinoic acid (RA) signaling, including retinoid X receptors (RXRs). Exogenous RA initiated neuritogenesis in normal adult retinas and primary retinal cultures and exacerbated it in LIRD retinas. However, LIRD-induced neuritogenesis was partly attenuated in retinol dehydrogenase knockout (Rdh12(-/-)) mice and by aldehyde dehydrogenase inhibitors. We further found that LIRD rapidly increased the expression of glutamate receptor 2 and β Ca(2+)/calmodulin-dependent protein kinase II (βCaMKII). Pulldown assays demonstrated interaction between βCaMKII and RXRs, suggesting that CaMKII pathway regulates the activities of RXRs. RXR antagonists completely prevented and RXR agonists were more effective than RA in inducing neuritogenesis. Thus, RXRs are in the final common path and may be therapeutic targets to attenuate retinal remodeling and facilitate global intervention methods in blinding diseases and other neurodegenerative disorders.

Topics: Alcohol Oxidoreductases; Alitretinoin; Animals; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Disease Models, Animal; Mice; Mice, Inbred BALB C; Mice, Mutant Strains; Neurodegenerative Diseases; Primary Cell Culture; Receptors, AMPA; Receptors, Retinoic Acid; Retinal Cone Photoreceptor Cells; Retinal Degeneration; Retinal Rod Photoreceptor Cells; Retinoic Acid Receptor alpha; Retinoic Acid Receptor gamma; Signal Transduction; Tretinoin; Vision, Ocular

Neural tube defects (NTDs) are complex congenital malformations resulting from incomplete neurulation in embryo. Despite surgical repair of the defect, most of the patients who survive with NTDs have a multiple system handicap due to neuron deficiency of the defective spinal cord. In this study, we successfully devised a prenatal surgical approach and transplanted mesenchymal stem cells (MSCs) to foetal rat spinal column to treat retinoic acid induced NTDs in rat. Transplanted MSCs survived, grew and expressed markers of neurons, glia and myoblasts in the defective spinal cord. MSCs expressed and perhaps induced the surrounding spinal tissue to express neurotrophic factors. In addition, MSC reduced spinal tissue apoptosis in NTD. Our results suggested that prenatal MSC transplantation could treat spinal neuron deficiency in NTDs by the regeneration of neurons and reduced spinal neuron death in the defective spinal cord.

Topics: Animals; Apoptosis; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Female; Fetus; Fluorescent Antibody Technique; In Situ Nick-End Labeling; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Microinjections; Pregnancy; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Spina Bifida Cystica; Spinal Cord; Tretinoin

We have developed inorganically-coated all-trans retinoic acid (atRA) nanoparticles, nano-sized egg-like particles of atRA (NANOEGG®-atRA). The purpose of this study was to determine the effects of NANOEGG®-atRA on corneal wound healing in vivo and in vitro.. A rabbit corneal epithelial wound healing model was exposed to different concentrations of NANOEGG®-atRA. Wound healing was serially quantified as the ratio of fluorescein-stained area at the selected times to that at baseline. After wound closure, the barrier function of the cornea was determined using low concentrations of tropicamide. At the completion of the experiments, the corneal epithelium was histologically examined. For the in vitro studies, linear scratch wounds were made on cultured SV40-immortalized human corneal epithelial cells (HCE-T). Then, the cells were exposed to different concentrations of NANOEGG®-atRA, and wound healing was determined by the degree of closure of the scratch wound. In addition, the effects of NANOEGG®-atRA on the proliferation of HCE-T cells were determined by WST-8 assays.. Exposure to NANOEGG®-atRA decreased the injured area 24 hrs after the ablation. The maximum effect of NANOEGG®-atRA was observed at a concentration of 33 mM. Histologically, no abnormal or differentiated corneal epithelial cells were observed in the histological sections treated with NANOEGG®-atRA. The tropicamide-induced pupillary dilation was significantly slowed in the eyes treated with NANOEGG®-atRA. NANOEGG®-atRA at concentrations of 3.3 and 33 nM induced earlier wound closure in vitro, but did not induce proliferation of HCE-T cells.. NANOEGG®-atRA promotes wound healing and should be considered for the treatment of wounds of the corneal epithelium.

Topics: Animals; Biological Transport; Cell Movement; Cell Proliferation; Cells, Cultured; Cornea; Corneal Injuries; Disease Models, Animal; Drug Carriers; Epithelium, Corneal; Fluorophotometry; Keratolytic Agents; Male; Membrane Proteins; Nanoparticles; Occludin; Phosphoproteins; Rabbits; Tretinoin; Wound Healing; Zonula Occludens-1 Protein

Congenital spina bifida aperta is a common congenital malformation in children and has an incidence of 1‰ to 5‰ in China. However, we currently lack specific biomarkers for screening or prenatal diagnosis and there is no method to entirely cure or prevent such defects. In this study, we used two-dimensional gel electrophoresis (2-DE)/mass spectrometry (MS) to characterize differentially expressed proteins in amniotic-fluid samples (AFSs) of embryonic day (E) 17.5 rat fetuses with spina bifida aperta induced by retinoic acid (RA). We identified five proteins differentially expressed in AFSs of spina bifida aperta, including three upregulated proteins (transferrin, alpha-1 antiproteinase and signal recognition particle receptor, B subunit [SRPRB] 55 kDa), two downregulated proteins (apolipoprotein A IV [APO A4] and Srprb 77 kDa). Specifically, we found 11 alpha-1 fetoprotein (AFP) fragments that were downregulated and 35 AFP fragments that were upregulated in AFSs from embryos with spina bifida aperta. Of the downregulated AFP fragments, 72.7% (8/11) were confined to the AFP N-terminus (amino acids [aas] 25-440) and 77.1% (27/35) of upregulated AFP fragments were confined to the AFP C-terminus (aas 340-596). We also confirmed APO A4 and AFP by immunoblot analysis. This is the first comparative proteomic study of AFSs from rat fetuses with spina bifida aperta. We demonstrate proteomic alterations in the AFS of spina bifida aperta, which may provide new insights in neural tube defects and contribute to the prenatal screening.

Topics: alpha-Fetoproteins; Amniotic Fluid; Animals; Disease Models, Animal; Electrophoresis, Gel, Two-Dimensional; Female; Immunoblotting; Pregnancy; Protein Structure, Tertiary; Proteomics; Rats; Rats, Wistar; Spina Bifida Cystica; Time Factors; Tretinoin

The homeobox transcription factor PITX2 is a known regulator of mammalian ocular development, and human PITX2 mutations are associated with Axenfeld-Rieger syndrome (ARS). However, the treatment of patients with ARS remains mostly supportive and palliative.. The authors used molecular genetic, pharmacologic, and embryologic techniques to study the biology of ARS in a zebrafish model that uses transgenes to mark neural crest and muscle cells in the head.. The authors demonstrated in vivo that pitx2 is a key downstream target of retinoic acid (RA) in craniofacial development, and this pathway is required for coordinating neural crest, mesoderm, and ocular development. pitx2a knockdown using morpholino oligonucleotides disrupts jaw and pharyngeal arch formation and recapitulates ocular characteristics of ARS, including corneal and iris stroma maldevelopment. These phenotypes could be rescued with human PITX2A mRNA, demonstrating the specificity of the knockdown and evolutionary conservation of pitx2a function. Expression of the ARS dominant negative human PITX2A K50E allele also caused ARS-like phenotypes. Similarly, inhibition of RA synthesis in the developing eye (genetic or pharmacologic) disrupted craniofacial and ocular development, and human PITX2A mRNA partially rescued these defects.. RA regulation of pitx2 is essential for coordinating interactions among neural crest, mesoderm, and developing eye. The marked evolutionary conservation of Pitx2 function in eye and craniofacial development makes zebrafish a potentially powerful model of ARS, amenable to in vivo experimentation and development of potential therapies.

Topics: Animals; Animals, Genetically Modified; Anterior Eye Segment; Disease Models, Animal; Eye; Eye Abnormalities; Eye Diseases, Hereditary; Facial Bones; Facial Muscles; Gene Expression Regulation, Developmental; Homeobox Protein PITX2; Homeodomain Proteins; In Situ Hybridization; Morpholinos; Polymerase Chain Reaction; RNA, Messenger; Skull; Transcription Factors; Tretinoin; Zebrafish

Topics: Actins; Animals; Collagen Type IV; Disease Models, Animal; Fibronectins; Fibrosis; Kidney; Kidney Diseases; Rats; Transforming Growth Factor beta1; Tretinoin; Ureteral Obstruction

Much evidence suggests that immune imbalance in the lung plays a crucial role in the development of pulmonary fibrosis. Recently, all-trans retinoic acid (ATRA) shifting the regulatory T/T-helper 17 (Treg/Th17) profile had been proven in some diseases. However, to date, the effect of ARTA of pulmonary fibrosis has not been examined from this aspect. The objective of this study was to study the effect of ATRA on bleomycin-induced pulmonary fibrosis in mice and its possible mechanism. Pulmonary fibrosis was induced in C57BL/6 male mice by intratracheal instillation of bleomycin (5 mg.kg(-1)), which were randomly divided into control, bleomycin, and ATRA groups. Five mice in each group were sacrificed on day 28 after intratracheal instillation. Hemotoxylin and eosin (H&E) and Masson staining were used for pathological examination, and hydroxyproline in lung tissue was measured. Interleukin (IL)-17A protein expression was observed in lung with immunohistochemistry. The expression of IL-17A, IL-10, IL-6, and transforming growth factor (TGF)-β mRNAs were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Th17 and Treg expression in spleen lymphocytes were measured by flow cytometry. H&E and masson staining and expression of hydroxyproline showed that ATRA significantly alleviated lung fibrosis than in the bleomycin group. The expression of IL-17A, IL-10, IL-6, and TGF-β mRNAs were higher in the bleomycin group than in the normal group. ATRA can decrease these cytokines except for IL-10. CD4+CD25+ Treg cell ratio in the bleomycin group was significantly lower than normal, but CD4+IL-17+ T cells was higher; ARTA reversed this kind of expression. ATRA may ease the bleomycin-induced pulmonary fibrosis by inhibiting the expression of IL-6 and TGF-β, shifting the Treg/Th17 ratio and reducing the secretion of IL-17A.

Topics: Animals; Antibiotics, Antineoplastic; Bleomycin; CD4-Positive T-Lymphocytes; Cell Count; Disease Models, Animal; Drug Therapy, Combination; Gene Expression; Hydroxyproline; Interleukins; Lung; Male; Mice; Mice, Inbred C57BL; Pulmonary Fibrosis; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta; Tretinoin

All-trans-retinoic acid (atRA) has been implicated in the local regulation of scleral proteoglycan synthesis in vivo. The purpose of the present study was to identify the enzymes involved in the synthesis of atRA during visually guided ocular growth, the cells involved in modulation of atRA biosynthesis in the choroid, and the effect of choroid-derived atRA on scleral proteoglycan synthesis.. Myopia was induced in White leghorn chicks by form deprivation for 10 days, followed by up to 15 days of unrestricted vision (recovery). Expression of atRA synthesizing enzymes was evaluated by semiquantitative qRT-PCR, in situ hybridization, and immunohistochemistry. atRA synthesis was measured in organ cultures of isolated choroids using LC-tandem MS quantification. Scleral proteoglycan synthesis was measured in vitro by the incorporation of (35)SO(4) in CPC-precipitable glycosaminoglycans. RESULTS; RALDH2 was the predominant RALDH transcript in the choroid (> 100-fold that of RALDH3). RALDH2 mRNA was elevated after 12 and 24 hours of recovery (60% and 188%, respectively; P < 0.01). The atRA concentration was significantly higher in cultures of choroids from 24-hour to 15-day recovering eyes than in paired controls (-195%; P < 0.01). Choroid conditioned medium from recovering choroids inhibited proteoglycan synthesis to 43% of controls (P < 0.02, paired t-test; n = 16) and produced a relative inhibition corresponding to a RA concentration of 7.20 × 10(-8) M.. The results of this study suggest that RALDH2 is the major retinal dehydrogenase in the chick choroid and is responsible for increased atRA synthesis in response to myopic defocus.

Topics: Aldehyde Dehydrogenase; Animals; Blotting, Northern; Blotting, Western; Chickens; Choroid; Disease Models, Animal; In Situ Hybridization; Myopia; Proteoglycans; Retinal Dehydrogenase; Reverse Transcriptase Polymerase Chain Reaction; Sclera; Tretinoin

Connexin 43 (Cx43), a major gap junction protein, is necessary for alveologenesis and plays an important role in the differentiation of type II to type I alveolar epithelial cells. Knockout mice of Cx43 display severe pulmonary hypoplasia (PH). Prenatal administration of retinoic acid (RA) is known to stimulate alveologenesis in nitrofen-induced PH. Recent studies revealed that retinoids upregulate Cx43 expression. We hypothesized that gene expression of Cx43 is downregulated during alveologenesis and that administration of RA upregulates Cx43 expression in the nitrofen-induced PH.. Pregnant rats were exposed to olive oil or nitrofen on day 9 (D9) of gestation. Retinoic acid was given intraperitoneally on D18, D19, and D20. Fetal lungs were harvested on D18 and D21 and divided into control, nitrofen, control+RA (D21), and nitrofen+RA (D21). The Cx43 expression levels were determined using reverse transcription polymerase chain reaction and immunohistochemistry.. On D18 and D21, Cx43 relative messenger RNA expression levels were significantly downregulated in nitrofen compared with those in the control group. On D21, expression levels of Cx43 were significantly upregulated in nitrofen+RA and control+RA compared with those in nitrofen group. Immunohistochemical studies confirmed these results.. Downregulation of Cx43 expression may interfere with normal alveologenesis. Upregulation of Cx43 pulmonary gene expression after RA treatment may promote lung growth by stimulating alveologenesis in nitrofen-induced PH.

Topics: Animals; Cell Differentiation; Connexin 43; Disease Models, Animal; Drug Evaluation, Preclinical; Epithelial Cells; Female; Fetal Therapies; Gene Expression Regulation, Developmental; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Injections, Intraperitoneal; Lung; Phenyl Ethers; Pregnancy; Random Allocation; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Respiratory Mucosa; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin; Up-Regulation

Nur77 and its family members Nurr1 and Nor-1 are inducible orphan nuclear receptors that orchestrate cellular responses to diverse extracellular signals. In epithelia, Nur77 can act as a potent proapoptotic molecule in response to cellular stress, suggesting a possible role for this nuclear receptor in the tissue response to injury. Here, we found that Nur77 promotes epithelial cell apoptosis after AKI. Injury of proximal tubular epithelial cells rapidly and strongly induced Nur77, Nor-1, and Nurr1 both in vitro and in vivo. After renal ischemia-reperfusion, Nurr77-deficient mice exhibited less apoptosis of tubular epithelial cells and better renal function than wild-type mice. Nur77-mediated renal injury involved a conformational change of Bcl2 and an increase in the protein levels of proapoptotic Bcl-xS. Ligand-activated retinoic acid receptors repressed Nur77 induction and function. Pretreatment of wild-type mice with retinoic acid before renal ischemia-reperfusion blunted the induction of Nur77, conferred protection of renal function, attenuated renal histologic injury, and reduced the expression of epithelial-derived proinflammatory cytokines. Retinoic acid also inhibited hypoxia-mediated induction of proinflammatory cytokines in cultured renal epithelial cells. Results obtained from proximal tubule cultures derived from Nur77-deficient mice suggested that the inhibition of Nur77 expression mediated the renoprotective effects of retinoic acid. In summary, Nur77 promotes epithelial apoptosis after ischemia-reperfusion injury, and retinoic acid-mediated inhibition of Nur77 expression is a promising therapeutic strategy for the prevention of AKI.

Topics: Acute Kidney Injury; Animals; Apoptosis; Cells, Cultured; Dimethyl Sulfoxide; Disease Models, Animal; DNA-Binding Proteins; Epithelial Cells; In Situ Hybridization; Kidney Function Tests; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nuclear Receptor Subfamily 4, Group A, Member 1; Random Allocation; Reference Values; Reperfusion Injury; Severity of Illness Index; Tretinoin

The process by which the periderm transitions to stratified epidermis with the establishment of the skin barrier is unknown. Understanding the cellular and molecular processes involved is crucial for the treatment of human pathologies, where abnormal skin development and barrier dysfunction are associated with hypothermia and perinatal dehydration. For the first time, we demonstrate that retinoic acid (RA) levels are important for periderm desquamation, embryonic skin differentiation and barrier formation. Although excess exogenous RA has been known to have teratogenic effects, little is known about the consequences of elevated endogenous retinoids in skin during embryogenesis. Absence of cytochrome P450, family 26, subfamily b, polypeptide 1 (Cyp26b1), a retinoic-acid-degrading enzyme, results in aberrant epidermal differentiation and filaggrin expression, defective cornified envelopes and skin barrier formation, in conjunction with peridermal retention. We show that these alterations are RA dependent because administration of exogenous RA in vivo and to organotypic skin cultures phenocopy Cyp26b1(-/-) skin abnormalities. Furthermore, utilizing the Flaky tail (Ft/Ft) mice, a mouse model for human ichthyosis, characterized by mutations in the filaggrin gene, we establish that proper differentiation and barrier formation is a prerequisite for periderm sloughing. These results are important in understanding pathologies associated with abnormal embryonic skin development and barrier dysfunction.

Topics: Animals; Cytochrome P-450 Enzyme System; Disease Models, Animal; Filaggrin Proteins; Intermediate Filament Proteins; Mice; Mice, Knockout; Retinoic Acid 4-Hydroxylase; Skin; Tretinoin

Acute promyelocytic leukemia (APL), a cytogenetically distinct subtype of acute myeloid leukemia (AML), characterized by the t(15;17)-associated PML-RARA fusion, has been successfully treated with therapy utilizing all-trans-retinoic acid (ATRA) to differentiate leukemic blasts. However, among patients with non-APL AML, ATRA-based treatment has not been effective. Here we show that, through epigenetic reprogramming, inhibitors of lysine-specific demethylase 1 (LSD1, also called KDM1A), including tranylcypromine (TCP), unlocked the ATRA-driven therapeutic response in non-APL AML. LSD1 inhibition did not lead to a large-scale increase in histone 3 Lys4 dimethylation (H3K4(me2)) across the genome, but it did increase H3K4(me2) and expression of myeloid-differentiation-associated genes. Notably, treatment with ATRA plus TCP markedly diminished the engraftment of primary human AML cells in vivo in nonobese diabetic (NOD)-severe combined immunodeficient (SCID) mice, suggesting that ATRA in combination with TCP may target leukemia-initiating cells. Furthermore, initiation of ATRA plus TCP treatment 15 d after engraftment of human AML cells in NOD-SCID γ (with interleukin-2 (IL-2) receptor γ chain deficiency) mice also revealed the ATRA plus TCP drug combination to have a potent anti-leukemic effect that was superior to treatment with either drug alone. These data identify LSD1 as a therapeutic target and strongly suggest that it may contribute to AML pathogenesis by inhibiting the normal pro-differentiative function of ATRA, paving the way for new combinatorial therapies for AML.

Topics: Animals; Antigens, CD34; Apoptosis; CD11b Antigen; Cell Differentiation; Cells, Cultured; Cytokines; Disease Models, Animal; Drug Interactions; Enzyme Inhibitors; Female; Flow Cytometry; Gene Expression Regulation; Histone Demethylases; Humans; Leukemia, Myeloid, Acute; Lysine; Mice; Mice, Inbred NOD; Mice, SCID; RNA, Small Interfering; Stem Cell Factor; Time Factors; Transplants; Tranylcypromine; Tretinoin

To determine the effects of all-trans-retinoic acid (RA) on establishment and growth of endometrial lesions, peritoneal interleukin-6 (IL-6) and macrophage chemotactic factor-1 (MCP-1) concentrations, and CD38, CD11b, and F4/80 expression on peritoneal macrophages in an immunocompetent mouse model of endometriosis.. Experimental transplantation study using mice.. Academic medical center.. C57BL/6 recipient mice and syngeneic green fluorescent protein transgenic (GFP+) mice.. Recipient mice were inoculated with GFP+ minced uterine tissue to induce endometriosis and treated with RA (400 nmol/day) or vehicle for 17 days (3 days before to 14 days after tissue injection).. Total number of GFP+ implants in recipient mice, number of implants showing visible blood vessels, total volume of established lesions per mouse, concentrations of IL-6 and MCP-1 in peritoneal fluid, and expression of CD11b, F4/80, and CD38 on peritoneal macrophages.. Retinoic acid treatment for 17 days reduced the number of implants versus controls and decreased the frequency of lesions with vessels. Peritoneal washings in RA-treated animals had lower concentrations of IL-6 and MCP-1 than controls 3 days after endometrial inoculation and lower levels of IL-6 on day 14 after inoculation. Concomitant with these effects on day 14, CD38, CD11b, and F4/80 were higher on macrophages from RA-treated mice versus controls.. The development of endometriotic implants is inhibited by RA. This effect may be caused, at least in part, by reduced IL-6 and MCP-1 production and enhanced differentiation of peritoneal macrophages.

Topics: Animals; Antineoplastic Agents; Cell Differentiation; Chemokine CCL2; Disease Models, Animal; Endometriosis; Female; Green Fluorescent Proteins; Immunocompetence; Interleukin-6; Macrophages; Mice; Mice, Inbred C57BL; Mice, Transgenic; Peritoneum; Transplants; Tretinoin; Uterus

We have recently proposed that retinoic acid receptor (NR1B) is a promising target of neuroprotective therapy for intracerebral hemorrhage, since pretreatment of mice with an NR1B1/NR1B2 agonist Am80 attenuated various pathological and neurological abnormalities associated with the disease. In the present study we further addressed the effects of retinoids as potential therapeutic drugs, using a collagenase-induced model of intracerebral hemorrhage. Daily oral administration of all-trans retinoic acid (ATRA; 5 and 15 mg/kg), a naturally occurring NR1B agonist, from 1 day before collagenase injection significantly inhibited loss of neurons within the hematoma. ATRA in the same treatment regimen also decreased the number of activated microglia/macrophages around the hematoma but did not affect the hematoma volume. ATRA (15 mg/kg) as well as Am80 (5mg/kg) rescued neurons in the central region of hematoma, even when drug administration was started from 6h after induction of intracerebral hemorrhage. However, in this post-treatment regimen, only Am80 significantly decreased the number of activated microglia/macrophages. With regard to neurological deficits, both ATRA (15 mg/kg) and Am80 (5mg/kg) given in the post-treatment regimen improved performance of mice in the beam-walking test and the modified limb-placing test. ATRA and Am80 also significantly attenuated damage of axon tracts as revealed by amyloid precursor protein immunohistochemistry. These results underscore potential therapeutic values of NR1B agonists for intracerebral hemorrhage.

Topics: Animals; Bacterial Proteins; Benzoates; Brain; Cell Count; Cerebral Hemorrhage; Collagenases; Disease Models, Animal; Dose-Response Relationship, Drug; Macrophage Activation; Macrophages; Male; Mice; Mice, Inbred C57BL; Microbial Collagenase; Microglia; Neurons; Neuroprotective Agents; Psychomotor Disorders; Receptors, Retinoic Acid; Retinoids; Tetrahydronaphthalenes; Time Factors; Tretinoin

Spina bifida is a complex congenital malformation resulting from failure of fusion in the spinal neural tube during embryogenesis. However, the cellular mechanism underlying spina bifida is not fully understood. Here, we investigated cell apoptosis in whole embryos and proliferation of neural progenitor cells in the spinal neural tube during neurulation in all-trans retinoic acid (atRA)-induced spina bifida in fetal rats. Cell apoptosis was assessed by TUNEL assay on whole-mount and serially sectioned samples of rat embryos with spina bifida. Cell proliferation of lumbo-sacral neural progenitor cells was assessed by staining for the mitotic marker Ki67 and pH3. We found an excess of apoptosis in the neuroepithelium of embryos with spina bifida, which became more marked as embryos progress from E11 to E13. Conversely, there was a reduction in cell proliferation in spina bifida embryos, with a progressively greater difference from controls with stage from E11 to 13. Thus, atRA-induced spina bifida in rat shows perturbed apoptosis and proliferation of neural progenitors in the lumbo-sacral spinal cord during embryonic development, which might contribute to the pathogenesis of spina bifida.

Topics: Analysis of Variance; Animals; Animals, Newborn; Antineoplastic Agents; Apoptosis; Cell Proliferation; Disease Models, Animal; Embryo, Mammalian; Epithelium; Female; Gene Expression Regulation, Developmental; In Situ Nick-End Labeling; Lumbosacral Region; Male; Neural Tube; Pregnancy; Prenatal Exposure Delayed Effects; Procollagen-Proline Dioxygenase; Rats; Rats, Wistar; Spina Bifida Cystica; Tretinoin

Transgenic mice expressing dominant-negative retinoic acid receptor (RAR) α specifically in the liver exhibit steatohepatitis, which leads to the development of liver tumors. Although the cause of steatohepatitis in these mice is unknown, diminished hepatic expression of insulin-like growth factor-1 suggests that insulin resistance may be involved. In the present study, we examined the effects of retinoids on insulin resistance in mice to gain further insight into the mechanisms responsible for this condition. Dietary administration of all-trans-retinoic acid (ATRA) significantly improved insulin sensitivity in C57BL/6J mice, which served as a model for high-fat, high-fructose diet-induced nonalcoholic fatty liver disease (NAFLD). The same effect was observed in genetically insulin-resistant KK-A(y) mice, occurring in concert with activation of leptin-signaling pathway proteins, including signal transducer and activator of transcription 3 (STAT3) and Janus kinase 2. However, such an effect was not observed in leptin-deficient ob/ob mice. ATRA treatment significantly up-regulated leptin receptor (LEPR) expression in the livers of NAFLD mice. In agreement with these observations, in vitro experiments showed that in the presence of leptin, ATRA directly induced LEPR gene expression through RARα, resulting in enhancement of STAT3 and insulin-induced insulin receptor substrate 1 phosphorylation. A selective RARα/β agonist, Am80, also enhanced hepatic LEPR expression and STAT3 phosphorylation and ameliorated insulin resistance in KK-A(y) mice.. We discovered an unrecognized mechanism of retinoid action for the activation of hepatic leptin signaling, which resulted in enhanced insulin sensitivity in two mouse models of insulin resistance. Our data suggest that retinoids might have potential for treating NAFLD associated with insulin resistance.

Topics: Animals; Cells, Cultured; Disease Models, Animal; Fatty Liver; Hepatocytes; Immunohistochemistry; Insulin Resistance; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Non-alcoholic Fatty Liver Disease; Random Allocation; Receptors, Leptin; Reference Values; Sensitivity and Specificity; Signal Transduction; Tretinoin; Up-Regulation

Exposure to retinoids for the treatment of acne has been linked to the etiology of inflammatory bowel disease (IBD). The intestinal mucus layer is an important structural barrier that is disrupted in IBD. Retinoid-induced alteration of mucus physiology has been postulated as a mechanism linking retinoid treatment to IBD; however, there is little direct evidence for this interaction. The zebrafish larva is an emerging model system for investigating the pathogenesis of IBD. Importantly, this system allows components of the innate immune system, including mucus physiology, to be studied in isolation from the adaptive immune system. This study reports the characterization of a novel zebrafish larval model of IBD-like enterocolitis induced by exposure to dextran sodium sulfate (DSS). The DSS-induced enterocolitis model was found to recapitulate several aspects of the zebrafish trinitrobenzene-sulfonic-acid (TNBS)-induced enterocolitis model, including neutrophilic inflammation that was microbiota-dependent and responsive to pharmacological intervention. Furthermore, the DSS-induced enterocolitis model was found to be a tractable model of stress-induced mucus production and was subsequently used to identify a role for retinoic acid (RA) in suppressing both physiological and pathological intestinal mucin production. Suppression of mucin production by RA increased the susceptibility of zebrafish larvae to enterocolitis when challenged with enterocolitic agents. This study illustrates a direct effect of retinoid administration on intestinal mucus physiology and, subsequently, on the progression of intestinal inflammation.

Topics: Animals; Dextran Sulfate; Disease Models, Animal; Enterocolitis; Inflammation; Intestinal Mucosa; Intestines; Larva; Metagenome; Mice; Mucins; Mucus; Neutrophils; Phenotype; Tretinoin; Trinitrobenzenesulfonic Acid; Zebrafish

Retinoic acid (RA) is a diverse regulator of immune responses. Although RA promotes natural killer T (NKT) cell activation in vitro by increasing CD1d expression on antigen-presenting cells (APCs), the direct effects of RA on NKT-cell responses in vivo are not known. In the present study, we demonstrated the effect of RA on the severity of Con A-induced hepatitis and molecular changes of NKT cells. First, we demonstrated that Con A-induced liver damage was ameliorated by RA. In correlation with cytokine levels in serum, RA regulated the production of IFN-γ and IL-4 but not TNF-α by NKT cells without influencing the NKT-cell activation status. However, RA did not alleviate α-GalCer-induced liver injury, even though it reduced IFN-γ and IL-4 but not TNF-α levels in serum. This regulation was also detected when liver mononuclear cells (MNCs) or NKT hybridoma cells were treated with RA in vitro. The regulatory effect of RA on NKT cells was mediated by RAR-α, and RA reduced the phosphorylation of MAPK. These results suggest that RA differentially modulates the production of effector cytokines by NKT cells in hepatitis, and the suppressive effect of RA on hepatitis varies with the pathogenic mechanism of liver injury.

Topics: Animals; Blotting, Western; Concanavalin A; Disease Models, Animal; Female; Galactosylceramides; Gene Expression Regulation; Hepatitis; Interferon-gamma; Interleukin-4; Kaplan-Meier Estimate; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Real-Time Polymerase Chain Reaction; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; RNA; Specific Pathogen-Free Organisms; Tretinoin; Tumor Necrosis Factor-alpha

We sought to investigate the effects of antenatal retinoic acid on the pulmonary vasculature and vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) expression in a nitrofen-induced congenital diaphragmatic hernia (CDH) model.. Rat fetuses were exposed to nitrofen at gestational day 9.5 and/or all-trans retinoic acid (ATRA) at gestational days 18.5-20.5. We assessed lung growth, airway, and vascular morphometry. VEGF, VEGFR1, and VEGFR2 expression was analyzed by Western blotting and immunohistochemistry. Continuous data were analyzed by analysis of variance and Kruskal-Wallis test.. CDH decreased lung to body weight ratio, increased mean linear intercept and mean transection length/airspace, and decreased mean airspace cord length. ATRA did not affect lung growth or morphometry. CDH increased proportional medial wall thickness of arterioles while ATRA reduced it. ATRA recovered expression of VEGF and receptors, which were reduced in CDH.. Retinoic acid and VEGF may provide pathways for preventing pulmonary hypertension in CDH.

Topics: Analysis of Variance; Angiogenesis Inducing Agents; Animals; Arterioles; Biomarkers; Blotting, Western; Disease Models, Animal; Female; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Lung; Phenyl Ethers; Pregnancy; Rats; Rats, Sprague-Dawley; Teratogens; Treatment Outcome; Tretinoin; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1; Vascular Endothelial Growth Factor Receptor-2

Retinoic acid is the active vitamin A derivative and is well-known to have diverse immunomodulatory actions. In this study, we investigated the impact of all-trans retinoic acid (ATRA), a biologic key metabolite of vitamin A, on the development of arthritis and the pathophysiologic mechanisms by which ATRA might have antiarthritic effects in animal model of rheumatoid arthritis (RA; collagen-induced arthritis [CIA] in DBA/1J mice). We showed that treatment with ATRA markedly suppressed the clinical and histologic signs of arthritis in the CIA mice. It reduced the expression of IL-17 in the arthritic joints. Interestingly, Foxp3(+) regulatory T cells were markedly increased and IL-17-producing CD4(+) T cells (Th17 cells) were decreased in the spleens of ATRA-treated mice. In vitro treatment with ATRA induced the expression of Foxp3 and repressed the IL-17 expression in the CD4(+) T cells in mice. ATRA suppressed the production of total IgG and IgG2a in splenocytes that were stimulated by LPS. It also reduced serum levels of total IgG and IgG2 anti-collagen Abs and germinal center formation in CIA mice. In addition, the ATRA-treated mice showed decreased osteoclast formation in arthritic joints. Moreover, ATRA downregulated the expression of receptor activator of NF-κB ligand, the leading player of osteoclastogenesis, in the CD4(+) T cells and fibroblast-like synoviocytes from patients with RA. Furthermore, ATRA prevented both human monocytes and mice bone marrow-derived monocytes/macrophage cells from differentiating into osteoclasts. These data suggest ATRA might be an effective treatment modality for RA patients.

Topics: Animals; Arthritis, Rheumatoid; Cattle; Collagen Type II; Disease Models, Animal; Immunity, Humoral; Inflammation; Inflammation Mediators; Male; Mice; Mice, Inbred DBA; Osteoclasts; Th17 Cells; Tretinoin

Retinoic acid (RA) is a biologically active derivative of vitamin A. Previous studies have demonstrated that RA has protective effects against damage caused by H2O2 or oxygen-glucose deprivation in mesangial and PC12 cells. Pretreatment with 9-cis-retinoic acid (9cRA) reduced infarction and TUNEL labeling in cerebral cortex as well as attenuated neurological deficits after distal middle cerebral artery occlusion in rats. The purpose of this study was to examine a protective role of 9cRA in dopaminergic (DA) neurons in a typical rodent model of Parkinson's disease (PD).. The protective role of 9cRA was first examined in rat primary ventromesencephalic culture. Treatment with 9cRA significantly reduced 6-hydroxydopamine (6-OHDA)-mediated cell death and TUNEL labeling in cultured dopaminergic neurons. The protective effect was also examined in adult male rats. Animals received unilateral 6-OHDA lesioning at the left medial forebrain bundle on day 0. Methamphetamine -induced rotational behavior was examined on days 6, 20 and 30 after lesioning. Animals were separated into 2 groups to balance rotational behavior and lesion extent on day 6 and were treated with either 9cRA or vehicle (i.c.v. on day 7 + intra-nasal from day 8 to day 14). Post-treatment with 9cRA significantly reduced methamphetamine -mediated ipislateral rotation at 20 and 30 days after lesioning. In vivo voltammetry was used to examine DA overflow in striatum. Treatment with 9cRA significantly increased KCl -evoked DA release in the lesioned striatum. 9cRA also increased tyrosine hydroxylase (+) cell number in the lesioned nigra as determined by unbiased stereology.. Our data suggests that early post-treatment with 9cRA has a protective effect against neurodegeneration in nigrostriatal DA neurons in an animal model of PD.

Topics: Adrenergic Agents; Analysis of Variance; Animals; Corpus Striatum; Disease Models, Animal; Dopaminergic Neurons; Dose-Response Relationship, Drug; Embryo, Mammalian; Female; Functional Laterality; In Situ Nick-End Labeling; Male; Mesencephalon; Motor Activity; Neurodegenerative Diseases; Neurons; Oxidopamine; Parkinson Disease; Potassium Chloride; Pregnancy; Rats; Rats, Sprague-Dawley; Rotation; Substantia Nigra; Tretinoin; Tyrosine 3-Monooxygenase

Prenatal treatment with retinoic acid (RA) has been reported to stimulate alveologenesis in hypoplastic lungs (HL) in the nitrofen model of congenital diaphragmatic hernia (CDH). Parathyroid hormone-related protein (PTHrP) promotes alveolar maturation by stimulating surfactant production, regulated by PTHrP receptor (PTHrP-R). PTHrP knockout and PTHrP-R null mice both exhibit pulmonary hypoplasia. We have recently reported that nitrofen inhibits PTHrP signaling in the nitrofen-induced HL. Because both PTHrP and PTHrP-R genes have RA-inducible element, we hypothesized that prenatal administration of RA upregulates pulmonary gene expression of PTHrP and PTHrP-R in the nitrofen-induced HL.. Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). RA was given on days D18, D19 and D20. Fetal lungs were obtained on D21 and divided into four groups: control, control + RA, nitrofen, nitrofen + RA. RT-PCR and Immunohistochemistry were performed to investigate the pulmonary PTHrP and PTHrP-R gene and protein expression in each group, respectively.. The pulmonary gene expression levels of PTHrP and PTHrP-R were significantly increased in nitrofen + RA group compared to nitrofen group (p < 0.05). Immunoreactivity of PTHrP and PTHrP-R was also remarkably increased in nitrofen + RA group compared to nitrofen group.. Upregulation of PTHrP and PTHrP-R genes after prenatal treatment with RA in the nitrofen-induced HL suggests that RA may have a therapeutic potential in reverting lung hypoplasia in CDH, by stimulating surfactant production and alveolar maturation.

Topics: Analysis of Variance; Animals; Disease Models, Animal; Female; Lung; Lung Diseases; Olive Oil; Parathyroid Hormone-Related Protein; Phenyl Ethers; Plant Oils; Pregnancy; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Tretinoin; Up-Regulation

Diabetes mellitus (DM) is a primary risk factor for cardiovascular diseases and heart failure. Activation of the retinoic acid receptor (RAR) and retinoid X receptor (RXR) has an anti-diabetic effect; but, a role in diabetic cardiomyopathy remains unclear. Using neonatal and adult cardiomyocytes, we determined the role of RAR and RXR in hyperglycemia-induced apoptosis and expression of renin-angiotensin system (RAS) components. Decreased nuclear expression of RARα and RXRα, activation of apoptotic signaling and cell apoptosis was observed in high glucose (HG) treated neonatal and adult cardiomyocytes and diabetic hearts in Zucker diabetic fatty (ZDF) rats. HG-induced apoptosis and reactive oxygen species (ROS) generation was prevented by both RAR and RXR agonists. Silencing expression of RARα and RXRα, by small interference RNA, promoted apoptosis under normal conditions and significantly enhanced HG-induced apoptosis, indicating that RARα and RXRα are required in regulating cell apoptotic signaling. Blocking angiotensin type 1 receptor (AT(1) R); but, not AT(2) R, attenuated HG-induced apoptosis and ROS generation. Moreover, HG induced gene expression of angiotensinogen, renin, AT(1) R, and angiotensin II (Ang II) synthesis were inhibited by RARα agonists and promoted by silencing RARα. Activation of RXRα, downregulated the expression of AT(1) R; and RXRα silencing accelerated HG induced expression of angiotensinogen and Ang II synthesis, whereas there was no significant effect on renin gene expression. These results indicate that reduction in the expression of RARα and RXRα has an important role in hyperglycemia mediated apoptosis and expression of RAS components. Activation of RAR/RXR signaling protects cardiomyocytes from hyperglycemia, by reducing oxidative stress and inhibition of the RAS.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Animals, Newborn; Apoptosis; Blood Glucose; Cells, Cultured; Diabetes Mellitus; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Hyperglycemia; Hypoglycemic Agents; Male; Myocytes, Cardiac; Oxidative Stress; Rats; Rats, Sprague-Dawley; Rats, Zucker; Reactive Oxygen Species; Receptor, Angiotensin, Type 1; Receptors, Retinoic Acid; Renin-Angiotensin System; Retinoic Acid Receptor alpha; Retinoid X Receptor alpha; RNA Interference; RNA, Messenger; Signal Transduction; Time Factors; Tretinoin

Freeze-lesioned regions of the forebrain cortex provide adequate environment for growth of non-differentiated neural progenitors, but do not support their neuron formation. Reduced oxygen supply, among numerous factors, was suspected to impair neuronal cell fate commitment. In the present study, proliferation and differentiation of neural stem/progenitor cells were investigated at different oxygen levels both in vitro and in vivo. Low (1% atmospheric) oxygen supply did not affect the in vitro viability and proliferation of stem cells or the transcription of "stemness" genes but impaired the viability of committed neuronal progenitors and the expression of proneural and neuronal genes. Consequently, the rate of in vitro neuron formation was markedly reduced under hypoxic conditions. In vivo, neural stem/progenitor cells survived and proliferated in freeze-lesioned adult mouse forebrains, but did not develop into neurons. Hypoperfusion-caused hypoxia in lesioned cortices was partially corrected by hyperbaric oxygen treatment (HBOT). HBOT, while reduced the rate of cell proliferation at the lesion site, resulted in sporadic neuron formation from implanted neural stem cells. The data indicate that in hypoxic brain areas, neural stem cells survive and proliferate, but neural tissue-type differentiation can not proceed. Oxygenation renders the damaged brain areas more permissive for tissue-type differentiation and may help the integration of neural stem/progenitor cells.

Topics: Animals; Antineoplastic Agents; Behavior, Animal; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cell Transplantation; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Green Fluorescent Proteins; Homeodomain Proteins; Hyperbaric Oxygenation; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-Ischemia, Brain; Locomotion; Male; Mice; Models, Biological; Nanog Homeobox Protein; Nerve Tissue Proteins; Neural Plate; Neuroepithelial Cells; Oxygen; SOXB1 Transcription Factors; Stem Cells; Time Factors; Transfection; Tretinoin

Nitrofen-induced congenital diaphragmatic hernia (CDH) model has been widely used to investigate the pathogenesis of pulmonary hypoplasia (PH) in CDH. Recent studies have suggested that retinoids may be involved in the molecular mechanisms of PH in CDH. Prenatal treatment with retinoic acid (RA) has been reported to improve the growth of hypoplastic lung in the nitrofen CDH model. Midkine (MK), a RA-responsive growth factor, plays key roles in various organogenesis including lung development. In fetal lung, MK mRNA expression has its peak at E13.5-E16.5 and is markedly decreased during mid-to-late gestation, indicating its important role in early lung morphogenesis. We designed this study to investigate the hypothesis that the pulmonary MK gene expression is downregulated in the early lung morphogenesis in the nitrofen-induced PH, and to evaluate the effect of prenatal RA treatment on pulmonary MK gene expression in the nitrofen-induced CDH model.. Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal lungs were harvested on D15, D18, and D21 and divided into control, nitrofen with or without CDH [CDH(+) or CDH(-)]. In addition, RA was given on days D18, D19, and D20 and fetal lungs were harvested on D21, and then divided into control + RA and nitrofen + RA. The pulmonary gene expression levels of MK were evaluated by real-time RT-PCR and statistically analyzed. Immunohistochemistry was also performed to examine protein expression/distribution of MK in fetal lung.. The relative mRNA expression levels of MK were significantly downregulated in nitrofen group compared to controls at D15 ((§)p < 0.01), whereas there were no significant differences at D18 and D21. MK gene expression levels were significantly upregulated in nitrofen + RA (0.71 ± 0.17) compared to the control (0.35 ± 0.16), CDH(-) (0.24 ± 0.15), CDH(+) (0.39 ± 0.19) and control + RA (0.47 ± 0.13) (*p < 0.05). Immunoreactivity of MK was also markedly decreased in nitrofen lungs compared to controls on D15, and increased in nitrofen + RA lungs compared to the other lungs on D21.. Downregulation of MK gene on D15 may contribute to primary PH in the nitrofen CDH model by disrupting early lung morphogenesis. Upregulation of MK gene after RA treatment in the nitrofen-induced hypoplastic lung suggests that RA may have a therapeutic potential to rescue PH in CDH through RA-responsive growth factor signaling.

Topics: Animals; Cytokines; Disease Models, Animal; Down-Regulation; Female; Gene Expression Regulation, Developmental; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Immunohistochemistry; Lung; Midkine; Pregnancy; Pregnancy, Animal; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin

Excess dietary fat can cause hepatic steatosis, which can progress into severe liver disorders including steatohepatitis and cirrhosis. Steroid receptor coactivator-3 (SRC-3), a member of the p160 coactivator family, is reported as a key regulator of adipogenesis and energy homeostasis. We sought to determine the influence of SRC-3 on hepatic steatosis and the mechanism beneath.. The influence of siRNA-mediated SRC-3 silencing on hepatic lipid accumulation was assessed in HepG2 cells. The molecular mechanism of SRC-3 regulation of hepatic lipid metabolism was also studied. Moreover, the effect of SRC-3 ablation on hepatic steatosis was examined in SRC-3 deficient mice.. In this study, we report that SRC-3 ablation reduces palmitic acid-induced lipid accumulation in HepG2 cells. Moreover, deletion of SRC-3 ameliorates hepatic steatosis and inflammation response in mice fed a high fat diet (HFD). These metabolic improvements can presumably be explained by the reduction in chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) expression and the subsequent elevation in peroxisome proliferator-activated receptor α (PPARα) level. At the molecular level, SRC-3 interacts with retinoic receptor α (RARα) to activate COUP-TFII expression under all-trans retinoic acid (ARTA) treatment.. These findings indicate a crucial role for SRC-3 in regulating hepatic lipid metabolism and provide the possible novel inner mechanisms.

Topics: Animals; COUP Transcription Factor II; Dietary Fats; Disease Models, Animal; Fatty Liver; Gene Knockdown Techniques; Hep G2 Cells; Humans; Immunohistochemistry; Lipid Metabolism; Liver Cirrhosis, Experimental; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Non-alcoholic Fatty Liver Disease; Nuclear Receptor Coactivator 3; PPAR alpha; Promoter Regions, Genetic; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; RNA Interference; RNA, Small Interfering; Tretinoin

Retinoic acids, a group of natural and synthetic vitamin A derivatives, have potent anti-proliferative, anti-inflammatory and anti-fibrotic properties. We investigated the therapeutic effect of all-trans-retinoic acid (ATRA) on unilateral ureteral obstruction (UUO) model mice.. First, to evaluate the prophylactic effect, we administered 0.5 mg of ATRA for 3 days before UUO (UUO ATRA). Then, to evaluate the therapeutic effects, we administered 0.5 mg of ATRA 3 days after UUO (Day 3 ATRA). We compared the histological changes and immunostaining of macrophages, α-smooth muscle actin (α-SMA) and collagen I, and mRNA expression of monocyte chemotactic protein-1 (MCP-1), transforming growth factor (TGF)-β(1) and TGF-β R-II by RT-PCR 7 days after UUO.. In the UUO ATRA and Day 3 ATRA groups, we observed a significant improvement in histological and immunological findings, including macrophage infiltration and improved expression of MCP-1, TGF-β(1), α-SMA and collagen I compared with the UUO Day 7 group.. ATRA treatment is not only an effective prophylactic strategy, but also a therapeutic strategy for the treatment of progressive renal fibrosis in diseased kidneys.

Topics: Actins; Animals; Chemokine CCL2; Collagen Type I; Disease Models, Animal; Female; Fibrosis; Kidney Diseases; Mice; Mice, Inbred C57BL; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Tretinoin; Ureteral Obstruction

Recent studies have suggested that retinoids may be involved in the molecular mechanisms of pulmonary hypoplasia (PH) in congenital diaphragmatic hernia (CDH). Connective tissue growth factor (CTGF) plays a key role in foetal lung development and remodelling during later gestation. CTGF knockout mice exhibit PH with similar characteristics to the human and nitrofen-induced PH. Prenatal administration of retinoic acid (RA) has been shown to stimulate alveologenesis in nitrofen-induced PH. In vitro studies have revealed that RA can induce CTGF gene expression. We hypothesized that pulmonary gene expression of CTGF is downregulated during the later stages of lung development, and that prenatal administration of RA upregulates CTGF in the nitrofen CDH model.. Pregnant rats were exposed to either olive oil or nitrofen on day 9 (D9) of gestation. RA was given intraperitoneally on D18, D19 and D20. Foetuses were harvested on D21 and divided into control, CDH, control + RA and CDH + RA group. Pulmonary CTGF gene and protein expression levels were determined using RT-PCR and immunohistochemistry.. On D21, CTGF relative mRNA expression levels were significantly downregulated in CDH group compared to controls. After RA treatment, expression levels of CTGF were significantly upregulated in CDH + RA and control + RA compared to the CDH group. Immunohistochemical studies confirmed these results.. Downregulation of pulmonary CTGF gene and protein expression during later stages of lung development may interfere with normal alveologenesis in the nitrofen CDH model. Upregulation of CTGF pulmonary gene expression after prenatal RA treatment may promote lung growth by promoting alveologenesis in the nitrofen-induced CDH model.

Topics: Animals; Connective Tissue Growth Factor; Disease Models, Animal; Female; Gene Expression Regulation, Developmental; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Immunohistochemistry; Phenyl Ethers; Pregnancy; Pregnancy, Animal; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin; Up-Regulation

Cholestasis leads to liver cell death, fibrosis, cirrhosis, and eventually liver failure. Despite limited benefits, ursodeoxycholic acid (UDCA) is the only Food and Drug Administration-approved treatment for cholestatic disorders. Retinoic acid (RA) is a ligand for nuclear receptors that modulate bile salt homeostasis. RA also possesses immunomodulatory effects and is used to treat acute promyelocytic leukemia and inflammatory disorders such as psoriasis, acne, and rheumatoid arthritis. To test whether the supplementation of RA with UDCA is superior to UDCA alone for treating cholestasis, male Sprague-Dawley rats underwent common bile duct ligation (BDL) for 14 days and were treated with phosphate-buffered saline (PBS), UDCA, all-trans retinoic acid (atRA), or UDCA and atRA by gavage. Treatment with UDCA and atRA substantially improved animal growth rates, significantly reduced liver fibrosis and bile duct proliferation, and nearly eliminated liver necrosis after BDL. Reductions in the bile salt pool size and liver hydroxyproline content were also seen with treatment with atRA or atRA and UDCA versus PBS and UDCA. Furthermore, atRA and UDCA significantly reduced liver messenger RNA and/or protein expression of transforming growth factor β1 (Tgf-β1), collagen 1a1 (Col1A1), matrix metalloproteinase 2 (Mmp2), cytokeratin 19, α-smooth muscle actin (α-SMA), cytochrome P450 7A1 (Cyp7a1), tumor necrosis factor α, and interleukin-β1. The molecular mechanisms of this treatment were also assessed in human hepatocytes, hepatic stellate cells, and LX-2 cells. atRA alone or in combination with UDCA greatly repressed CYP7A1 expression in human hepatocytes and significantly inhibited COL1A1, MMP2, and α-SMA expression and/or activity in primary human hepatic stellate cells and LX-2 cells. Furthermore, atRA reduced TGF-β1-induced Smad2 phosphorylation in LX-2 cells.. Our findings indicate that the addition of RA to UDCA reduces the bile salt pool size and liver fibrosis and might be an effective supplemental therapy with UDCA for cholestatic diseases.

Topics: Animals; Bile Acids and Salts; Bile Ducts; Cell Proliferation; Cells, Cultured; Cholestasis, Intrahepatic; Cholesterol 7-alpha-Hydroxylase; Collagen Type I; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Hepatocytes; Humans; Ligation; Liver; Male; Matrix Metalloproteinase 2; Rats; Rats, Sprague-Dawley; Smad2 Protein; Tretinoin; Ursodeoxycholic Acid

The objective of this study was to determine whether amniotic fluid levels of glial acidic fibrillary protein (GFAP) would reflect myelomeningocele-related neurodegeneration in the rat model of retinoic acid-induced myelomeningocele, which is a model that is very similar to human myelomeningocele and develops the entire spectrum of disease severity including features of the Chiari II malformation.. Time-dated (embryonic day 10) pregnant Sprague-Dawley rats were gavage fed 60 mg/kg/bodyweight retinoic acid that had been dissolved in olive oil or olive oil alone. Myelomeningocele, retinoic acid-exposed no myelomeningocele, and control fetuses were harvested at specific time points throughout gestation. A standard set of pinching tests was performed to interrogate the sensorimotor reflex arc of hindpaws and tails. Amniotic fluid-GFAP levels were analyzed by standard enzyme-linked immunosorbent assay techniques.. Amniotic fluid-GFAP levels were similar between groups at embryonic days 14, 16, and 18, respectively. Compared with control fetuses, amniotic fluid GFAP levels were significantly increased in myelomeningocele fetuses at embryonic days 20 and 22 (P < .001). Defect size (P < .001), presence of clubfoot deformity (P = .0004), and absence of sensorimotor function (P < .01) at embryonic day 22 correlated with amniotic fluid-GFAP levels.. Amniotic fluid-GFAP levels appear to correlate with spinal cord injury as gestation proceeds in fetal rats with myelomeningocele.

Topics: Amniotic Fluid; Animals; Biomarkers; Chi-Square Distribution; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Fetus; Glial Fibrillary Acidic Protein; Immunohistochemistry; Meningomyelocele; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Tretinoin

Novel drug delivery systems, such as solid lipid nanoparticles (SLN), have been proposed to reduce retinoic acid (RA)-induced skin irritation. However, one question still remains: could it be accomplished without reducing efficacy? To evaluate this question the comedolytic effects and epidermal thickening of RA-loaded SLN were compared to the conventional RA formulations (gel or cream), as well as the potential of these formulations to induce skin irritation. The comedolytic effects and epidermal thickening of these formulations, both containing RA at 0.01 or 0.05%, were investigated in a rhino mouse model, while the studies of RA-induced skin irritation were evaluated through rabbit skin irritation tests and in the rhino mouse model. RA-loaded SLN, as compared to the placebo, produced a comedolytic effect with a significant reduction of the utricle diameter, which proved to be similar to that observed for marketed gels or creams regardless of the RA concentration. RA formulations (SLN or marketed cream) also induced an epidermal proliferation leading to a thickened epidermis in treated animals. In both animals studied (rhino mice and rabbits), the RA-loaded SLN, when compared to conventional formulations, promoted a significant reduction in RA-induced skin irritation (erythema and scaling). Then, RA-loaded SLN represents an interesting alternative to reduce RA-induced skin irritation without reducing efficacy, and constitutes an innovative approach for the topical treatment of acne with RA.

Topics: Animals; Cell Proliferation; Dermatitis, Contact; Disease Models, Animal; Drug Delivery Systems; Epidermis; Erythema; Gels; Glutamates; Humans; Lipids; Mice; Nanoparticles; Rabbits; Skin Irritancy Tests; Tretinoin

Pulmonary hypoplasia (PH) is the main cause of mortality in newborns with congenital diaphragmatic hernia (CDH). Prenatal administration of retinoic acid (RA) stimulates alveologenesis in the nitrofen-induced pulmonary hypoplasia. Insulin-like growth factor receptors (IGFRs) play a crucial role in alveologenesis during lung development. We recently demonstrated that IGFRs were downregulated in later stages of lung development in the nitrofen CDH model. Several studies suggest the ability of RA to regulate insulin-like growth factor signaling. We hypothesized that IGFRs pulmonary gene expression is upregulated after the administration of RA in the nitrofen-induced CDH model.. Pregnant rats were exposed to either olive oil or nitrofen on day 9 (D9) of gestation. RA was given intraperitoneally on days D18, D19, and D20. Fetal lungs were dissected on D21 and divided into control, control + RA, CDH, and CDH + RA group. IGFRs gene and protein expression were determined using RT-PCR and immunohistochemistry.. mRNA expression levels of IGFRs were significantly increased in control + RA and CDH + RA compared with CDH group. Immunoreactivity of IGFRs was markedly increased in control + RA and CDH + RA compared with CDH lungs.. Upregulation of pulmonary gene and protein expression of IGFRs after prenatal RA treatment in the nitrofen model suggests that RA may promote lung growth by stimulating IGFRs mediated alveologenesis.

Topics: Animals; Animals, Newborn; Disease Models, Animal; Down-Regulation; Female; Gene Expression Regulation, Developmental; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Immunohistochemistry; Lung; Lung Diseases; Phenyl Ethers; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Receptor, IGF Type 1; Receptor, IGF Type 2; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin; Up-Regulation

Parkinson's disease (PD) is a late-onset, progressive and neurodegenerative disorder of unknown etiology. Besides the other therapeutic approaches, new drug options in pharmacotherapy of PD are important. The aim of the present study was to investigate the effects of pioglitazone and retinoic acid, antioxidant and neuroprotective agents, on rotenone-induced model of PD in rats. Adult male Wistar rats (260-373 g) were subjects. Rotenone (2.5mg/kg, sc) was injected to rats for 70 days. At the end of rotenone administration, rats were treated with pioglitazone (10mg/kg, ip) and retinoic acid (1mg/kg, ip) or vehicles for 15 days. Then, rats were tested for evaluation of Parkinson signs by measurement of locomotor activity. In addition, dopamine levels were detected in striatum, hippocampus and hypothalamus in individual groups of control, rotenone and pioglitazone or retinoic acid-treated rats. Rotenone significantly reduced locomotor activity of the rats. It also significantly reduced dopamine levels in striatum and hippocampus, but not hypothalamus. Pioglitazone and retinoic acid reversed in reduction of locomotor activity significantly. Pioglitazone, but not retinoic acid, significantly reversed the reduced striatal dopamine level. Both drugs were ineffective on reduced levels of dopamine in hippocampus. Our results suggest that pioglitazone and retinoic acid have some beneficial effects on rotenone-induced model of PD in rats. Pioglitazone seems to be more effective than retinoic acid. These agents may be helpful for preventing or controlling of some signs of PD.

Topics: Animals; Antineoplastic Agents; Antioxidants; Disease Models, Animal; Hypoglycemic Agents; Male; Motor Activity; Neuroprotective Agents; Parkinson Disease, Secondary; Pioglitazone; Rats; Rats, Wistar; Rotenone; Thiazolidinediones; Tretinoin

Patients with pancreatic ductal adenocarcinoma are deficient in vitamin A, resulting in activation of pancreatic stellate cells (PSCs). We investigated whether restoration of retinol to PSCs restores their quiescence and affects adjacent cancer cells.. PSCs and cancer cell lines (AsPc1 and Capan1) were exposed to doses and isoforms of retinoic acid (RA) in 2-dimensional and 3-dimensional culture conditions (physiomimetic organotypic culture). The effects of all-trans retinoic acid (ATRA) were studied in LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre mice, a model of human pancreatic ductal adenocarcinoma.. After incubation with ATRA, PSCs were quiescent and had altered expression of genes that regulate proliferation, morphology, and motility; genes that encode cytoskeletal proteins and cytokines; and genes that control other functions, irrespective of culture conditions or dosage. In the organotypic model, and in mice, ATRA induced quiescence of PSCs and thereby reduced cancer cell proliferation and translocation of β-catenin to the nucleus, increased cancer cell apoptosis, and altered tumor morphology. ATRA reduced the motility of PSCs, so these cells created a "wall" at the junction between the tumor and the matrix that prevented cancer cell invasion. Restoring secreted frizzled-related protein 4 (sFRP4) secretion to quiescent PSCs reduced Wnt-β-catenin signaling in cancer cells and their invasive ability. Human primary and metastatic pancreatic tumor tissues stained strongly for cancer cell nuclear β-catenin but had low levels of sFRP4 (in cancer cells and PSCs).. RA induces quiescence and reduces motility of PSCs, leading to reduced proliferation and increased apoptosis of surrounding pancreatic cancer cells. RA isoforms might be developed as therapeutic reagents for pancreatic cancer.

Topics: Alitretinoin; Animals; Antineoplastic Agents; Apoptosis; beta Catenin; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cellular Senescence; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Humans; Isotretinoin; Mice; Mice, Mutant Strains; Pancreatic Neoplasms; Pancreatic Stellate Cells; Paracrine Communication; Proto-Oncogene Proteins; RNA Interference; Signal Transduction; Time Factors; Transcription, Genetic; Tretinoin; Wnt Proteins

Antley-Bixler syndrome (ABS) represents a group of heterogeneous disorders characterized by skeletal, cardiac, and urogenital abnormalities that have frequently been associated with mutations in fibroblast growth factor receptor 2 or cytochrome P450 reductase genes. In some ABS patients, reduced activity of the cholesterogenic cytochrome P450 CYP51A1, an ortholog of the mouse CYP51, and accumulation of lanosterol and 24,25-dihydrolanosterol has been reported, but the role of CYP51A1 in the ABS etiology has remained obscure. To test whether Cyp51 could be involved in generating an ABS-like phenotype, a mouse knock-out model was developed that exhibited several prenatal ABS-like features leading to lethality at embryonic day 15. Cyp51(-/-) mice had no functional Cyp51 mRNA and no immunodetectable CYP51 protein. The two CYP51 enzyme substrates (lanosterol and 24,25-dihydrolanosterol) were markedly accumulated. Cholesterol precursors downstream of the CYP51 enzymatic step were not detected, indicating that the targeting in this study blocked de novo cholesterol synthesis. This was reflected in the up-regulation of 10 cholesterol synthesis genes, with the exception of 7-dehydrocholesterol reductase. Lethality was ascribed to heart failure due to hypoplasia, ventricle septum, and epicardial and vasculogenesis defects, suggesting that Cyp51 deficiency was involved in heart development and coronary vessel formation. As the most likely downstream molecular mechanisms, alterations were identified in the sonic hedgehog and retinoic acid signaling pathways. Cyp51 knock-out mice provide evidence that Cyp51 is essential for embryogenesis and present a potential animal model for studying ABS syndrome in humans.

Topics: Animals; Antley-Bixler Syndrome Phenotype; Cholesterol; Disease Models, Animal; Embryo, Mammalian; Embryonic Development; Heart Failure; Hedgehog Proteins; Humans; Lanosterol; Mice; Mice, Knockout; Oxidoreductases Acting on CH-CH Group Donors; Pericardium; Receptor, Fibroblast Growth Factor, Type 2; Signal Transduction; Sterol 14-Demethylase; Tretinoin

Although the mechanism by which retinoic acid (RA) induces cleft palate has been intensely investigated, some controversies remain. Some researchers argue that RA inhibits apoptosis, resulting in a failure of palatal shelves to fuse, whereas others propose that RA disrupts elevation or retards the growth of palatal shelves. This study investigated the mechanism underlying RA-induced formation of cleft palate in the rat, focusing mainly on the role of apoptosis.. Using an RA-induced cleft palate model of Sprague-Dawley rats described in our previous study, we examined a total of 92 embryos. Retinoic acid was injected intraperitoneally in experimental group animals on embryonic day 11 (D11), a time when our previous study indicated that RA-induced cleft palate was maximally developed. Control animals were treated with normal saline mixed with sesame oil. Timed pregnant rats were killed by an overdose of ether on D13, D14, D15, D16, and D17, and 8 sections were prepared from the anterior to the posterior of the palate. Growth of palatal shelves was evaluated histologically by examining sections stained with hematoxylin-eosin, periodic acid-Schiff, trichrome, and cresyl violet. Differences in apoptosis were monitored using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays.. Histologic examinations revealed underdevelopment of palatal shelves in the experimental group compared with the control group. In the RA-treated group, the overall process of palatal shelf development was delayed 1 day, and palatal elevation was observed. In hard-palate areas of both groups, apoptosis was maximal immediately after the fusion of palatal shelves. In the soft-palate areas, the saline-treated group showed fusion of palatal shelves, whereas the RA-treated group showed retarded growth of palatal shelves that resulted in failure of palatal fusion. Moreover, apoptosis occurred before palatal contact.. Apoptotic manifestations did not differ between RA-induced cleft palates and control palates, suggesting that apoptosis makes a minimal contribution to the cleft palate formed in response to RA. Instead, growth retardation of the palatal shelves appears to play a major role in RA-induced cleft palate.

Topics: Animals; Apoptosis; Cleft Palate; Disease Models, Animal; Female; In Situ Nick-End Labeling; Pregnancy; Rats; Rats, Sprague-Dawley; Staining and Labeling; Tretinoin

Excess exogenous retinoic acid (RA) has been well documented to have teratogenic effects in the limb and craniofacial skeleton. Malformations that have been observed in this context include craniosynostosis, a common developmental defect of the skull that occurs in 1 in 2500 individuals and results from premature fusion of the cranial sutures. Despite these observations, a physiological role for RA during suture formation has not been demonstrated. Here, we present evidence that genetically based alterations in RA signaling interfere with human development. We have identified human null and hypomorphic mutations in the gene encoding the RA-degrading enzyme CYP26B1 that lead to skeletal and craniofacial anomalies, including fusions of long bones, calvarial bone hypoplasia, and craniosynostosis. Analyses of murine embryos exposed to a chemical inhibitor of Cyp26 enzymes and zebrafish lines with mutations in cyp26b1 suggest that the endochondral bone fusions are due to unrestricted chondrogenesis at the presumptive sites of joint formation within cartilaginous templates, whereas craniosynostosis is induced by a defect in osteoblastic differentiation. Ultrastructural analysis, in situ expression studies, and in vitro quantitative RT-PCR experiments of cellular markers of osseous differentiation indicate that the most likely cause for these phenomena is aberrant osteoblast-osteocyte transitioning. This work reveals a physiological role for RA in partitioning skeletal elements and in the maintenance of cranial suture patency.

Topics: Animals; Cell Differentiation; Cranial Sutures; Craniosynostoses; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Disease Models, Animal; Female; Fetal Death; Gene Expression Regulation, Developmental; Growth and Development; Humans; Mice; Osteoblasts; Osteogenesis; Polymorphism, Genetic; Pregnancy; Retinoic Acid 4-Hydroxylase; Sequence Homology, Amino Acid; Tretinoin; Zebrafish; Zebrafish Proteins

Retinoic acid (RA), produced by intestinal epithelial cells (IECs) and dendritic cells (DCs) promotes the induction of regulatory T cells (Tregs) and decreases the induction of T-helper (Th)17 cells.. We studied the roles of RA in mice that overproduce tumor necrosis factor (TNF) and develop chronic ileitis (TNF_ARE mice). We assessed the frequency and function of CD103+ DCs, Th17 cells, and Tregs by flow cytometry, and we measured expression of cytokines and retinaldehyde dehydrogenase (RALDH) enzymes in ileum samples, DCs, and IECs by real-time polymerase chain reaction. We quantified RA by electrochemical analysis and examined the effect of RA supplementation on TNF-induced ileitis using histologic, coculture, and suppression assays and flow cytometry.. Numbers of CD103+ DCs decreased in the inflamed ilea of mice with chronic disease; RA synthetic machinery (RALDH1,2) was down-regulated. Nevertheless, the proportion of CD4+, CD25+, FoxP3+ Tregs increased, indicating an alternate source for RA. IECs responded to reduced levels of RA by up-regulating RALDH3 in vivo and in vitro. Net tissue levels of RA remained lower in TNF+ARE than wild-type mice, indicating that epithelial up-regulation of RALDH3 could not maintain adequate concentrations of RA, probably because of loss of IEC mass. RA supplementation significantly attenuated disease by increasing the number and function of CD103+ DCs and Tregs and reducing Th17 cells.. Reduced levels of RA appear to induce IECs to up-regulate synthesis of RA. RA supplementation attenuates ileitis through its effects on CD103+ DCs, Tregs, and Th17 cells. RA supplementation might offer therapeutic benefit in Crohn's disease.

Topics: Animals; Antigens, CD; Cell Proliferation; Cells, Cultured; Coculture Techniques; Cytokines; Dendritic Cells; Disease Models, Animal; Forkhead Transcription Factors; Ileitis; Integrin alpha Chains; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Knockout; T-Lymphocytes, Regulatory; Th17 Cells; Tretinoin

The study aimed to predict effective human jejunal permeability (P(eff)) using a biophysical model based on parametrized paracellular, aqueous boundary layer, and transcellular permeabilities, and the villus-fold surface area expansion factor (k(VF)). Published human jejunal data (119 P(eff), 53 compounds) were analyzed by a regression procedure incorporating a dual-pore size paracellular model. Transcellular permeability, scaled by k(VF), was equated to that of Caco-2 at pH 6.5. The biophysical model predicted human jejunal permeability data within the experimental uncertainty. This investigation revealed several surprising predictions: (i) many molecules permeate predominantly (but not exclusively) by the paracellular route, (ii) the aqueous boundary layer thickness in the intestinal perfusion experiments is larger than expected, (iii) the mucosal surface area in awake humans is apparently nearly entirely accessible to drug absorption, and (iv) the relative "leakiness" of the human jejunum is not so different from that observed in a number of published Caco-2 studies.

Topics: Animals; Disease Models, Animal; Dogs; Humans; Jejunal Diseases; Kidney Diseases; Models, Biological; Permeability; Porosity; Regression Analysis

Vitamin A deficiency (VAD) is associated with increased susceptibility to carcinogenesis in animal models and elevated risk for a number of human cancers. Here, we found that CYP26A1, the gene encoding a cytochrome P450 enzyme specifically involved in metabolic inactivation of retinoic acid (RA), the most active vitamin A derivative, is highly expressed in 42% (27/65) of primary breast cancers. We also showed that enhanced expression of CYP26A1 suppresses cellular responses to anoikis and consequently promotes anchorage-independent growth. This transformed phenotype was sufficient to markedly increase tumorigenic and metastatic potential. Suppression of CYP26A1 significantly reversed the CYP26A1-mediated oncogenic characteristics, suggesting a direct link between intracellular RA status and tumorigenicity. Our observations provide strong evidence for oncogenic and cell survival properties of CYP26A1 in carcinogenesis, and suggest mechanisms whereby VAD might promote cancer development.

Topics: Animals; Anoikis; Breast Neoplasms; Carcinogenicity Tests; Carcinogens; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Cytochrome P-450 Enzyme System; Disease Models, Animal; Drug Interactions; Gene Expression Profiling; Humans; Mice; Mice, Knockout; Neoplasms; Retinoic Acid 4-Hydroxylase; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin; Tumor Cells, Cultured; Vitamin A; Vitamin A Deficiency

DNA vaccination and all-trans retinoic acid (ATRA) result in a survival advantage in a mouse model of acute promyelocytic leukemia (APL). Depletion of CD4(+) or CD8(+) cells abolished this effect. CD4(+) depletions of long-term survivors resulted in relapse and death within 3 months, thus demonstrating the need of both CD4(+) and CD8(+) subsets for the generation of DNA-driven antileukemic immune responses and underscoring a crucial role of CD4(+) cells in the maintenance of durable remissions. Degranulation and cytotoxic carboxyfluorescein diacetate succinimidyl ester-based assays showed major histocompatibility complex-restricted APL-specific T cell-mediated immune responses. Sorted APL-specific CD8(+)CD107a(+) T cells showed an increase of antileukemic activity. Effectors from ATRA + DNA-treated mice were shown to secrete interferon-gamma when stimulated with either APL cells or peptides from the promyelocytic leukemia-RARalpha vaccine-derived sequences as detected by ELISpot assays. Our results demonstrate that DNA vaccination with ATRA confers the effective boosting of interferon-gamma-producing and cytotoxic T cells in the leukemic mice.

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Combined Modality Therapy; Disease Models, Animal; Humans; Immunity, Cellular; Leukemia, Promyelocytic, Acute; Lymphocyte Activation; Mice; Oncogene Proteins, Fusion; Survival Analysis; Treatment Outcome; Tretinoin; Tumor Cells, Cultured; Vaccines, DNA; Xenograft Model Antitumor Assays

Calcification of heart valve structures is the most common form of valvular disease and is characterized by the appearance of bone-like phenotypes within affected structures. Despite the clinical significance, the underlying etiology of disease onset and progression is largely unknown and valve replacement remains the most effective treatment. The SRY-related transcription factor Sox9 is expressed in developing and mature heart valves, and its function is required for expression of cartilage-associated proteins, similar to its role in chondrogenesis. In addition to cartilage-associated defects, mice with reduced sox9 function develop skeletal bone prematurely; however, the ability of sox9 deficiency to promote ectopic osteogenic phenotypes in heart valves has not been examined.. This study aims to determine the role of Sox9 in maintaining connective tissue homeostasis in mature heart valves using in vivo and in vitro approaches.. Using histological and molecular analyses, we report that, from 3 months of age, Sox9(fl/+);Col2a1-cre mice develop calcific lesions in heart valve leaflets associated with increased expression of bone-related genes and activation of inflammation and matrix remodeling processes. Consistently, ectopic calcification is also observed following direct knockdown of Sox9 in heart valves in vitro. Furthermore, we show that retinoic acid treatment in mature heart valves is sufficient to promote calcific processes in vitro, which can be attenuated by Sox9 overexpression.. This study provides insight into the molecular mechanisms of heart valve calcification and identifies reduced Sox9 function as a potential genetic basis for calcific valvular disease.

Topics: Age Factors; Aging; Animals; Animals, Newborn; Calcinosis; Calcium; Chick Embryo; Collagen Type II; Disease Models, Animal; Down-Regulation; Extracellular Matrix; Female; Gene Knockdown Techniques; Genotype; Heart Valve Diseases; Inflammation; Integrases; Male; Mice; Mice, Transgenic; Mitral Valve; Osteogenesis; Phenotype; SOX9 Transcription Factor; Tissue Culture Techniques; Transfection; Tretinoin; Tricuspid Valve

Hirschsprung disease is a serious disorder of enteric nervous system (ENS) development caused by the failure of ENS precursor migration into the distal bowel. We now demonstrate that retinoic acid (RA) is crucial for GDNF-induced ENS precursor migration, cell polarization and lamellipodia formation, and that vitamin A depletion causes distal bowel aganglionosis in serum retinol-binding-protein-deficient (Rbp4(-/-)) mice. Ret heterozygosity increases the incidence and severity of distal bowel aganglionosis induced by vitamin A deficiency in Rbp4(-/-) animals. Furthermore, RA reduces phosphatase and tensin homolog (Pten) accumulation in migrating cells, whereas Pten overexpression slows ENS precursor migration. Collectively, these data support the hypothesis that vitamin A deficiency is a non-genetic risk factor that increases Hirschsprung disease penetrance and expressivity, suggesting that some cases of Hirschsprung disease might be preventable by optimizing maternal nutrition.

Topics: Animals; Cell Movement; Disease Models, Animal; Embryonic Stem Cells; Enteric Nervous System; Female; Glial Cell Line-Derived Neurotrophic Factor; Heterozygote; Hirschsprung Disease; Humans; In Vitro Techniques; Maternal Nutritional Physiological Phenomena; Mice; Mice, Inbred C57BL; Mice, Knockout; Models, Biological; Pregnancy; PTEN Phosphohydrolase; Receptors, Retinoic Acid; Retinol-Binding Proteins, Plasma; Signal Transduction; Tretinoin; Vitamin A; Vitamin A Deficiency

Loss of Tbx1 and decrease of retinoic acid (RA) synthesis result in DiGeorge/velocardiofacial syndrome (DGS/VCFS)-like phenotypes in mouse models, including defects in septation of the outflow tract of the heart and anomalies of pharyngeal arch-derived structures including arteries of the head and neck, laryngeal-tracheal cartilage, and thymus/parathyroid. Wild-type levels of T-box transcription factor (Tbx)1 and RA signaling are required for normal pharyngeal arch artery development. Recent studies have shown that reduction of RA or loss of Tbx1 alters the contribution of second heart field (SHF) progenitor cells to the elongating heart tube.. Here we tested whether Tbx1 and the RA signaling pathway interact during the deployment of the SHF and formation of the mature aortic arch.. Molecular markers of the SHF, neural crest and smooth muscle cells, were analyzed in Raldh2;Tbx1 compound heterozygous mutants. Our results revealed that the SHF and outflow tract develop normally in Raldh2(+/-);Tbx1(+/-) embryos. However, we found that decreased levels of RA accelerate the recovery from arterial growth delay observed in Tbx1(+/-) mutant embryos. This compensation coincides with the differentiation of smooth muscle cells in the 4th pharyngeal arch arteries, and is associated with severity of neural crest cell migration defects observed in these mutants.. Our data suggest that differences in levels of embryonic RA may contribute to the variability in great artery anomalies observed in DGS/VCFS patients.

Topics: Aldehyde Oxidoreductases; Animals; Aorta, Thoracic; Branchial Region; Cell Differentiation; Crosses, Genetic; DiGeorge Syndrome; Disease Models, Animal; Down-Regulation; Embryo, Mammalian; Gene Expression Regulation, Developmental; Genotype; Gestational Age; Heart; Heterozygote; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Muscle, Smooth, Vascular; Mutation; Neural Crest; Phenotype; Signal Transduction; T-Box Domain Proteins; Tissue Culture Techniques; Tretinoin

Alb/TGF-beta(1) transgenic mice overexpress active transforming growth factor-beta(1) (TGF-beta(1)) in the liver, leading to increased circulating levels of the cytokine and progressive renal fibrosis. This study was designed to explore if exogenous all-trans retinoic acid (tRA) prevents renal fibrosis in this animal model.. The retinoid profile in kidney and liver of wild-type and Alb/TGF-beta(1) transgenic mice was examined by high-performance liquid chromatography and slow-release pellets containing different amounts of tRA were implanted subcutaneously to treat the Alb/TGF-beta(1) transgenic mice, starting at 1 week of age; mice were sacrificed 2 weeks later.. Kidneys of 3-week-old wild-type mice had abundant tRA, which was completely absent in kidneys of the transgenic mice. Low doses of tRA (6-10.7 mg/kg/day) failed to affect renal fibrosis although it tended to suppress the mRNA expression of some molecular markers of fibrosis and retinal dehydrogenase 2 (RALDH2), a gene encoding a key tRA-synthesising enzyme. These tendencies disappeared, mortality tended to increase and RALDH2 and connective tissue growth factor (CTGF) mRNAs significantly increased in the medium-dose group (12.7-18.8 mg/kg/day). High doses (20.1-27.4 mg/kg/day) showed even higher toxicity with increased renal fibrosis and significant mortality.. Alb/TGF-beta(1) transgenic mice are characterised by depletion of endogenous renal tRA. Exogenous tRA dose-dependently increases mortality and kidney fibrosis, which is associated with dose-dependent regulation of renal RALDH2 and CTGF mRNA expression.

Topics: Animals; Connective Tissue Growth Factor; Disease Models, Animal; Fibrosis; Kidney; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Transforming Growth Factor beta1; Tretinoin

Topics: Aldehyde Oxidoreductases; Animals; Aorta, Thoracic; Branchial Region; Cell Differentiation; DiGeorge Syndrome; Disease Models, Animal; Genotype; Heart; Humans; Mice; Mice, Mutant Strains; Muscle, Smooth, Vascular; Mutation; Neural Crest; Phenotype; Signal Transduction; T-Box Domain Proteins; Tretinoin

An experimental study was carried out to investigate the efficacy of an anti-inflammatory and antiproliferative agent all-trans retinoic acid (ATRA) and an antioxidant agent zinc sulphate (ZnSO(4)) in the prevention of stricture after caustic esophageal burn in rats.. Esophageal burn was induced using 50% NaOH. Rats were divided into four groups as follows: group A (sham; n = 8), group B (control; n = 8), group C (treated with ATRA; n = 8) and group D (treated with ZnSO(4); n = 8). All rats were killed on the 28th day and esophageal tissues were evaluated for histopathologic damage score, hydroxyproline (HP) content and TGF-beta1 expression.. Significant difference was detected in terms of histopathologic damage score between groups B and C (p = 0.002). Although mean HP levels of groups C and D were lower than group B, statistical comparison was not significant. TGF-beta1 expression in group C was significantly lower than group B.. Zinc has not been found effective in the prevention of stricture formation. The results indicate that ATRA has a preventive effect in the development of fibrosis in an experimental model of caustic esophageal burns in rats.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Burns, Chemical; Caustics; Disease Models, Animal; Esophageal Stenosis; Esophagus; Oxidative Stress; Rats; Rats, Wistar; Tretinoin; Zinc Sulfate

All-trans retinoic acid (atRA) is an active metabolite of vitamin A with antioxidant effects. There have been few reports on the effects of atRA on liver ischemia/reperfusion (I/R) injury. Here we have used a rat liver ischemia/ reperfusion model to analyze the protective effect of atRA. Rats were administered with different does (5-15 mg/kg/d) of atRA intraperitoneally (i.p.) for 14 d before I/R. Partial (70%) hepatic ischemia was induced by clamping the hepatic artery, portal vein, and bile duct to the left and median lobes of the liver using a vascular clamp for 60 min, followed by 24 h of reperfusion. The serum aminotransferase (ALT and AST) and hepatic pathology were used to evaluate I/R injury. The results demonstrate that atRA pretreatment attenuates liver I/R injury by inhibiting the release of malondialdehyde (MDA) and by enhancing the activity of superoxide dismutase (SOD). To gain insight into the mechanism of the SOD up-regulation by atRA, the activity of p38 mitogenactivated protein kinase (p38MAKP) and Akt was measured. The results showed that the phosphorylation of p38MAPK and Akt paralleled the expression of manganese superoxide dismutase (MnSOD). That these activities are related was demonstrated by the addition of a p38 inhibitor which markedly decreased MnSOD levels. Taken together, our data reveal that atRA can protect liver from I/R injury by increaseing MnSOD, which is associated with an increased activity of p38MAPK and Akt.

Topics: Animals; Antioxidants; Disease Models, Animal; Liver; Liver Diseases; Male; Malondialdehyde; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Superoxide Dismutase; Tretinoin; Up-Regulation

The precise mechanism of pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) still remains unclear. Recently, prenatal treatment with retinoic acid (RA) has been reported to stimulate alveologenesis in hypoplastic lungs in the nitrofen model of CDH. The serine/threonine protein kinase B (AKT) plays a key role in lung morphogenesis through epithelial-mesenchymal interaction in phosphatidylinositide 3-kinase (PI3K)-dependent manner. It has been reported that the lung morphogenesis in explants in mice is interfered by inhibitors of PI3K-AKT signaling pathway. Furthermore, we have recently shown that nitrofen inhibits PI3K-AKT signaling during mid-to-late lung morphogenesis in the nitrofen-induced hypoplastic lung. We hypothesized that prenatal administration of RA upregulates pulmonary gene expression of PI3K and AKT in the nitrofen-induced hypoplastic lung.. Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). 5 mg/kg of RA was given on D18, D19 and D20. The fetuses were harvested on D21, and fetal lungs were obtained and divided into four groups: control, control + RA, nitrofen, nitrofen + RA. The mRNA expression levels of PI3K and AKT were analyzed in each lung by real-time RT-PCR and statistically analyzed. Immunohistochemistry was also performed to evaluate protein expression of PI3K and AKT in the fetal lungs at D21.. The pulmonary gene expression levels of PI3K and AKT were significantly upregulated in nitrofen + RA group compared to nitrofen group and control + RA group (p < 0.05), whereas there were no significant differences between controls and control + RA group. Immunoreactivity of PI3K and AKT was markedly increased in nitrofen + RA lungs compared to nitrofen-induced hypoplastic lungs.. Upregulation of PI3K and AKT genes after prenatal treatment with RA in the nitrofen-induced hypoplastic lung suggests that RA may have a therapeutic potential in modulating lung alveologenesis by stimulating epithelial-mesenchymal interaction via PI3K-AKT signaling.

Topics: Animals; Disease Models, Animal; Female; Fetal Diseases; Gene Expression Regulation, Developmental; Gestational Age; Hernia, Diaphragmatic; Immunohistochemistry; Lung; Morphogenesis; Phenyl Ethers; Pregnancy; Pregnancy, Animal; Prenatal Exposure Delayed Effects; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Tretinoin; Up-Regulation

To study the effects of deer tendons collagen on osteoporosis rats induced by retinoic acid.. Male Wistar rats were randomly divided into normal control group, model control group, deer tendons collagen high, medium and low-dose groups, osteoporosis rats of retinoic acid-induced were set up. Changes of body weight, bone weight, bone mineral density, bone histomorphometry, plasma phosphorus, calcium, alkaline phosphatase (ALP), bone mechanics were measured before and after treatment of deer tendons collagen.. Compared with model control group,after treated by deer tendons collagen, body weight, bone mineral density, bone weight was increased in varying degrees, bone histomorphometry parameters were significantly different, the ALP in plasma was significantly reduced, contents of Ca, P were increased, all indicators of bone mechanics were significantly higher.. Deer tendons collagen can prevent and treat retinoic acid-induced osteoporosis of rats.

Topics: Alkaline Phosphatase; Animals; Biomechanical Phenomena; Bone Density; Calcium; Collagen; Deer; Disease Models, Animal; Femur; Male; Materia Medica; Osteoporosis; Random Allocation; Rats; Rats, Wistar; Tendons; Tretinoin

Retinoic acid (RA) has been shown to induce congenital clubfoot in animal models, but it is unknown whether the effect of RA on the formation of clubfoot in vivo results from generalized growth retardation or from the specific effects of hindlimb skeletal development. Our experimental research was based on a clubfoot model treated by maternal administration of RA (120, 130 or 140 mg/kg body weight) as an intragastric dose on embryonic day 10 (E10), and a control group was administered with an equivalent dose of solvent. Prenatal RA exposure reduced fetal body weight, length and skeletal ossification of the hindlimb compared with the control fetuses in a dose-dependent manner. The normal development curves indicated that the RA-exposed fetuses showed delayed increase in body weight and skeletal ossification development. However, there was no uniform effect on the skeletons of the hindlimb, not least retardation in ossification and induction malformation on the talus and calcaneus. Our results demonstrated that prenatal RA exposure had retardation effects on the developing hindlimb skeleton that was independent of those on the overall fetal growth. The normal skeletal ossification showed that the talus and calcaneus were poorly ossified and they were delayed by almost one day in the RA 120 mg/kg group. Therefore, during the susceptible stages, different regions of the limb bud responded differently to the teratogenic effects of RA.

Topics: Abnormalities, Drug-Induced; Animals; Body Patterning; Bone Development; Clubfoot; Disease Models, Animal; Female; Fetal Development; Hindlimb; Osteogenesis; Pregnancy; Rats; Rats, Sprague-Dawley; Tretinoin

Treg are endowed with immunosuppressive activities and have been proposed as promising targets for the therapy of autoimmune diseases. As the suppressive capacity of Treg depends on their migration into the affected tissues, we tested here whether modulation of Treg homing would enhance their capacity to suppress inflammation in mouse models of inflammatory bowel disease. Retinoic acid (RA) was used to induce the gut-specific homing receptor alpha(4)beta(7) efficiently and, to some extent, the chemokine receptor CCR9 on in vitro expanded Treg. Upon transfer, RA-treated Treg were indeed more potent suppressors in an acute, small intestinal inflammation model, compared with Treg stimulated without RA. By contrast, the efficacy of Treg to resolve an established, chronic inflammation of the colon in the transfer colitis model was not affected by RA-treatment. In the latter model, a rapid loss of RA-induced alpha(4)beta(7) expression and de novo induction of alpha(4)beta(7) on previously negative cells was observed on transferred Treg, which implies that Treg acquire gut-seeking properties in vivo under inflammatory and/or lymphopenic conditions. Together, our data show that the induction of appropriate homing properties prior to transfer increases the protective potential of adoptively transferred Treg in acute, but not in chronic, inflammatory disorders of the gut.

Topics: Acute Disease; Adoptive Transfer; Animals; Cells, Cultured; Chronic Disease; Colitis; Disease Models, Animal; Homeodomain Proteins; Humans; Immunosuppression Therapy; Inflammation; Inflammatory Bowel Diseases; Integrins; Intestine, Small; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Receptors, CCR; Receptors, Lymphocyte Homing; T-Lymphocytes, Regulatory; Tretinoin

p27 is a cell cycle suppressor gene, whose protein is a negative regulator of cyclin/cdk complexes. p27 is also a potential target of retinoids in cancer prevention studies. In benign prostate hyperplasia (BPH), and in most carcinomas, p27(Kip1) is down-regulated, suggesting its potential resistance to retinoids. To test this hypothesis, we examined the efficacy of 9-cis retinoic acid (9cRA) to suppress prostate cell proliferation (PECP) and carcinogenesis in p27(Kip1) deficient mice.. p27(Kip1) deficient (-/-), heterozygous (+/-) and homozygous (+/+) mice were treated for 7 days with testosterone, 9cRA, or with both, and cell proliferation in dorsolateral prostate (DLP) was determined by BrdU labeling. Prostate carcinogenesis was induced by N-Methyl-N-Nitrosourea (MNU) and hormone stimulation.. PECP in DLP of two-month-old mice of all genotypes was similar but significantly increased in old p27-/- mice only. Testosterone treatment increased PECP in all three p27 genotypes with the highest values in p27-/- mice. p27(Kip1) deficiency did not affect the response of PEC to 9cRA and to 9cRA+testosterone. The decrease of p27(Kip1) in p27+/- and p27-/- mice progressively increased the incidence and frequency of PIN and tumors. 9cRA suppressed PIN in all three p27 genotypes and this was associated with decreased PECP and increased cellular senescence.. This data indicates that p27(Kip1) deficiency promotes prostate cell proliferation and carcinogenesis but does not affect 9cRA's potential to suppress prostate carcinogenesis, suggesting that patients with PIN and carcinomas lacking or having a low level of p27(Kip1) expression may also benefit from clinical trials with retinoids.

Topics: Alitretinoin; Animals; Antineoplastic Agents; Cell Cycle; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p27; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Genotype; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Prostatic Neoplasms; Retinoids; Tretinoin

To observe the prevention and therapeutic effects of tanshitone (TAN) on retinoic acid induced osteoporosis in mice.. The mice osteoporosis was induced by given retinoic acid intragastrically for two weeks. The histomorphological features of bone were observed and biochemical indexes in serum (Ca, P, ALP, TRAP, E2, BGP) were determined after the mice were given TAN at the dose of 40, 80, 160 mg x kg(-1) respectly.. Tanshinone can induce high conversion of osteoporosis. The levels of P, ALP, TRAP and BGP in the TAN groups were lower than the model group, while the E2 level was higher than the model group.. Tanshitone can prevent the loss bone in the experimental mice. The mechanism may be that it improves the level of estrogenic hormone and inhibits the high bone turnover.

Topics: Abietanes; Alkaline Phosphatase; Animals; Bone Density; Disease Models, Animal; Drugs, Chinese Herbal; Female; Humans; Male; Mice; Osteoporosis; Phenanthrenes; Tretinoin

The early post-exposure treatment with All-trans retinoic acid (ATRA) can reduce hair cell loss and hearing deterioration in mice in which permanent threshold shift has been induced.. One of the mechanism by which intense noise induces apoptosis of cochlea hair cells is the C-Jun NH(2)-terminal kinase (JNK) pathway. ATRA is a potent inhibitor of activator protein 1, a transcription factor of the JNK pathway. In this study we evaluated that the effect of post-exposure treatment of ATRA on noise-induced hearing loss and aimed to determine a time window for effective post-exposure treatment of ATRA.. All mice were exposed to white noise for 3 h per day for three consecutive days and induced permanent threshold shift. The treatment groups fed with ATRA from 1 h, one day, two days, and three days after noise exposure for five days were compared with mice fed with same dosage of sesame oil. We measured the threshold shifts of hearing and survival rates of hair cells on the cytocochleogram.. Mice fed with ATRA beginning within two days after noise had less threshold shifts and more hair cell survivals than mice fed with sesame oil.

Topics: Animals; Apoptosis; Disease Models, Animal; Evoked Potentials, Auditory, Brain Stem; Hair Cells, Auditory; Hearing Loss, Noise-Induced; JNK Mitogen-Activated Protein Kinases; Mice; Mice, Inbred BALB C; Transcription Factor AP-1; Tretinoin

Individuals with the birth defect synpolydactyly (SPD) have 1 or more digit duplicated and 2 or more digits fused together. One form of SPD is caused by polyalanine expansions in homeobox d13 (Hoxd13). Here we have used the naturally occurring mouse mutant that has the same mutation, the SPD homolog (Spdh) allele, and a similar phenotype, to investigate the molecular pathogenesis of SPD. A transgenic approach and crossing experiments showed that the Spdh allele is a combination of loss and gain of function. Here we identify retinaldehyde dehydrogenase 2 (Raldh2), the rate-limiting enzyme for retinoic acid (RA) synthesis in the limb, as a direct Hoxd13 target and show decreased RA production in limbs from Spdh/Spdh mice. Intrauterine treatment with RA restored pentadactyly in Spdh/Spdh mice. We further show that RA and WT Hoxd13 suppress chondrogenesis in mesenchymal progenitor cells, whereas Hoxd13 encoded by Spdh promotes cartilage formation in primary cells isolated from Spdh/Spdh limbs, and that this was associated with increased expression of Sox6/9. Increased Sox9 expression and ectopic cartilage formation in the interdigital mesenchyme of limbs from Spdh/Spdh mice suggest uncontrolled differentiation of these cells into the chondrocytic lineage. Thus, we propose that mutated Hoxd13 causes polydactyly in SPD by inducing extraneous interdigital chondrogenesis, both directly and indirectly, via a reduction in RA levels.

Topics: Aldehyde Oxidoreductases; Animals; Cells, Cultured; Chondrogenesis; Disease Models, Animal; Female; Homeodomain Proteins; Humans; Male; Mice; Mice, Transgenic; Mutation; Phenotype; Polydactyly; Syndactyly; Toes; Transcription Factors; Tretinoin

To investigate the role of activated protein C (APC) in cartilage degradation.. Chondrocyte expression of protein C, endothelial protein C receptor (EPCR), and thrombomodulin (TM) were evaluated by reverse transcription-polymerase chain reaction (RT-PCR). APC was immunolocalized in developing joints and in osteoarthritic (OA) cartilage from humans. The effect of APC on aggrecan and collagen degradation was examined in explant cultures of ovine cartilage in control cultures and in cultures stimulated with interleukin-1alpha (IL-1alpha), tumor necrosis factor alpha (TNFalpha), or retinoic acid (RetA), using colorimetric assays and Western blotting. Chondrocyte expression of matrix metalloproteinases (MMPs), ADAMTS, and tissue inhibitor of metalloproteinases (TIMPs) was measured by RT-PCR. MMP-2 and MMP-9 activity was evaluated by gelatin zymography and MMP-13 by fluorogenic assay.. Positive cellular immunostaining for APC was found at sites of MMP activity in developing joints and in OA, but not normal, cartilage. Chondrocytes expressed messenger RNA for protein C, EPCR, and TM, with the latter 2 levels increased by IL-1alpha and TNFalpha stimulation. APC augmented aggrecan release and initiated collagen breakdown in IL-1alpha-treated and TNFalpha-treated cartilage, but not in normal or in RetA-treated cartilage. APC-stimulated aggrecan and collagen breakdown were due to MMP activity but were not associated with modulation of MMP, ADAMTS, or TIMP expression. APC resulted in MMP-13 activation in cartilage cultures. APC could not directly activate proMMP-13, but it was associated with increased MMP-2 and MMP-9 activity.. APC may be a relevant activator of MMPs in cartilage and may play a role in progressive cartilage degradation in arthritis.

Topics: Aggrecans; Animals; Antigens, CD; Cartilage, Articular; Cells, Cultured; Chondrocytes; Collagen; Disease Models, Animal; Endothelial Protein C Receptor; Humans; Interleukin-1alpha; Matrix Metalloproteinase 13; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Osteoarthritis; Protein C; Proteoglycans; Receptors, Cell Surface; RNA, Messenger; Sheep; Thrombomodulin; Tretinoin; Tumor Necrosis Factor-alpha

The present study was to investigate the effects of rosmarinic acid (RA) in cultured RAW264.7 cells and experimental model of sepsis induced by cecal ligation and puncture in rats and the potential mechanism. Results showed that RA concentration dependently down-regulated the levels of TNF-alpha, IL-6, and high-mobility group box 1 protein in LPS-induced RAW264.7 cells, inhibited the IkappaB kinase pathway, and modulated nuclear factor-kappaB. Intravenous injection of RA alone or in combination with imipenem reduced cecal ligation and puncture-induced lethality in rats. In addition, serum levels of TNF-alpha, IL-6, high-mobility group box 1 protein, triggering receptor expressed on myeloid cells, and endotoxin were down-regulated; in contrast, serum level of IL-10 was up-regulated. Amelioration of hemodynamics and decrease in serum enzyme activities and myeloperoxidase in lung, liver, and small intestine were also observed after RA injection. These data indicate that the antisepsis effect of RA was mediated by decreasing local and systemic levels of a wide spectrum of inflammatory mediators. This article provides the first evidence that RA has the capacity to inactivate inflammatory response in sepsis. The anti-inflammatory mechanism of RA may inhibit activation of the nuclear factor- kappaB pathway by inhibiting IkappaB kinase activity.

Topics: Animals; Anti-Bacterial Agents; Cinnamates; Depsides; Disease Models, Animal; Endotoxins; Gene Expression Regulation; Hemodynamics; Humans; Imipenem; Inflammation; Male; Mice; Myeloid Cells; Rats; Rats, Sprague-Dawley; Rosmarinic Acid; Sepsis; Tretinoin

Mice bearing the mutated gene for Cu/Zn superoxide dismutase (G93A) are a good model for human amyotrophic lateral sclerosis (ALS). They develop progressive limb paralysis paralleled by loss of motor neurons of the cervical and lumbar spinal cord, which starts at 3-3.5 months of age and ends with death at 4-5 months. Several treatments have been attempted to delay clinical symptoms and to extend lifespan, and some have had modest beneficial effects. One such treatment, based on long-term administration of valproic acid (VPA), resulted in controversial results. We report here that, while dietary supplementation with high VPA dosage slows down motor neuron death, as assessed by measurement of a specific marker for cholinergic neurons in the spinal cord, it has no significant effect on lifespan. Recently, the hypothesis has been put forward that a deficiency of retinoic acid (RA) and its signaling may have a role in ALS. We report that long-term dietary supplementation with RA has no effect on the decrease of the cholinergic marker in the spinal cord, but it significantly shortens lifespan of G93A mice.

Topics: Acetylcholinesterase; Amyotrophic Lateral Sclerosis; Animal Feed; Animals; Antineoplastic Agents; Choline O-Acetyltransferase; Disease Models, Animal; Female; GABA Agents; Gene Dosage; Humans; Life Expectancy; Male; Mice; Mice, Transgenic; Nerve Degeneration; Superoxide Dismutase; Superoxide Dismutase-1; Tretinoin; Valproic Acid

Corrosion casting and immunohistochemical staining with anti-alpha smooth muscle actin and anti-CD34 was utilized to demonstrate the capillary plexus and venous system in control and malformed mouse hearts.. Outflow tract malformations (e.g., double outlet right ventricle, transposition of the great arteries, and common truncus arteriosus) were induced in progeny of pregnant mice by retinoic acid administration at day 8.5 of pregnancy.. Although control hearts exhibited areas in which capillaries tended to be oriented in parallel arrays, the orientation of capillaries in the respective areas of malformed hearts was chaotic and disorganized. The major branch of a conal vein in control hearts runs usually from the left side of the conus to its right side at the root of the pulmonary trunk and opens to the right atrium below the right auricle; thus, it has a curved course. On the other hand, a conal vein in malformed hearts courses from the left side or from the anterior side of the conus and tends to traverse straight upwards along the dextroposed aorta or along the aortopulmonary groove with its proximal part located outside of the heart. Other cardiac veins in outflow tract malformations are positioned in the same locations as in control hearts.. We postulate that the changed location of the conal vein and disorganized capillary plexus result from malformed morphogenesis of the outflow tract and/or a disturbed regulation of angiogenic growth factor release from the adjacent environment.

Topics: Animals; Capillaries; Coronary Vessel Anomalies; Disease Models, Animal; Female; Heart Defects, Congenital; Mice; Mice, Inbred BALB C; Models, Theoretical; Pregnancy; Tretinoin; Veins

The innate immune response of airway epithelial cells to airborne allergens initiates the development of T cell responses that are central to allergic inflammation. Although proteinase allergens induce the expression of interleukin 25, we show here that epithelial matrix metalloproteinase 7 (MMP7) was expressed during asthma and was required for the maximum activity of interleukin 25 in promoting the differentiation of T helper type 2 cells. Allergen-challenged Mmp7(-/-) mice had less airway hyper-reactivity and production of allergic inflammatory cytokines and higher expression of retinal dehydrogenase 1. Inhibition of retinal dehydrogenase 1 restored the asthma phenotype of Mmp7(-/-) mice and inhibited the responses of lung regulatory T cells, whereas exogenous administration of retinoic acid attenuated the asthma phenotype. Thus, MMP7 coordinates allergic lung inflammation by activating interleukin 25 while simultaneously inhibiting retinoid-dependent development of regulatory T cells.

Topics: Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cell Differentiation; Chromatography, High Pressure Liquid; Cytokines; Disease Models, Animal; Electrophoresis, Gel, Two-Dimensional; Humans; Immunohistochemistry; Interleukins; Lymphocyte Activation; Matrix Metalloproteinase 7; Mice; Mice, Inbred C57BL; Mice, Knockout; Proteomics; Respiratory Mucosa; Retinal Dehydrogenase; Reverse Transcriptase Polymerase Chain Reaction; Th2 Cells; Tretinoin

Vitamin A is an important regulator of the human immune system, especially in the gut. Recent studies have revealed that retinoic acid (RA) in gut-associated dendritic cells (DCs) enhances the transforming growth factor (TGF)-beta-dependent conversion of naïve T cells into regulatory T (Treg) cells. Thus, RA produced by DCs contributes to immune tolerance mechanisms in the gut. In the present study we focused on the effect of RA on the differentiation of the DC, and tried to clarify the role of DCs induced by RA in a murine colitis model.. Human peripheral blood CD14(+) monocytes were cultured with granulocyte-macrophage colony stimulation factor and interleukin (IL)-4, with or without synthetic RA, Am80. Differentiated DCs cultured with Am80 (Am-DCs) were compared with conventional monocyte-derived DCs (cDCs).. Am-DCs showed macrophage (Mphi)-like adherent phenotypes, and lacked the expression of the typical DC marker CD1a. Am-DCs produced less IL-12p70 and revealed less polarizing ability toward type 1 helper T cells (Th1) by allogeneic mixed lymphocyte reaction with naïve T cells. In addition, Am80 treatment ameliorated macro- and microscopic damage in dextran sodium sulfate-induced colitis in mice, and suppressed the colitis-induced elevation of IL-12 in the intestinal lamina propria.. RA might play an important role in gut immune tolerances via local generation of IL-12 hypoproductive DCs. RA may be a useful clinical treatment for Th1-mediated inflammatory diseases, especially those such as Crohn's disease occurring in the gut.

Topics: Animals; Antineoplastic Agents; Blotting, Western; Cell Differentiation; Cells, Cultured; Colitis; Dendritic Cells; Dextran Sulfate; Disease Models, Animal; Female; Humans; Interleukin-12; Lymphocyte Culture Test, Mixed; Mice; Mice, Inbred C57BL; Monocytes; Th1 Cells; Tretinoin

Many biological activities of all-trans-retinoic acid (RA) are mediated by the ligand-activated transcription factors termed retinoic acid receptors (RARs), but this hormone can also activate the nuclear receptor peroxisome proliferation-activated receptor beta/delta (PPARbeta/delta). We show here that adipocyte differentiation is accompanied by a shift in RA signaling which, in mature adipocytes, allows RA to activate both RARs and PPARbeta/delta, thereby enhancing lipolysis and depleting lipid stores. In vivo studies using a dietary-induced mouse model of obesity indicated that onset of obesity is accompanied by downregulation of adipose PPARbeta/delta expression and activity. RA treatment of obese mice induced expression of PPARbeta/delta and RAR target genes involved in regulation of lipid homeostasis, leading to weight loss and improved insulin responsiveness. RA treatment also restored adipose PPARbeta/delta expression. The data indicate that suppression of obesity and insulin resistance by RA is largely mediated by PPARbeta/delta and is further enhanced by activation of RARs. By targeting two nuclear receptors, RA may be a uniquely efficacious agent in the therapy and prevention of the metabolic syndrome.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adiposity; Animals; Cell Differentiation; Diet; Disease Models, Animal; Fatty Acid-Binding Proteins; Insulin Resistance; Lipolysis; Mice; Mice, Inbred C57BL; Neoplasm Proteins; Obesity; PPAR delta; PPAR-beta; Receptors, Retinoic Acid; Signal Transduction; Tretinoin

Cleft palate is one of the major malformations induced by retinoic acid in both rodents and humans. The purpose of the present study was to elucidate the mechanism by which all-trans retinoic acid (atRA) induces the cleft palate.. The cell cycle distribution of mouse embryonic palate mesenchymal (MEPM) cells under atRA (100 mg/kg) treatment on gestation day (GD) 10 or GD 12 were measured by immunohistochemistry and flow cytometry. The p21, phospho-Rb, Smad2/3, phospho-Smad2 and phospho-Smad3 protein expression levels were detected by western blot, respectively. Quantitative real-time PCR was performed for p21, Smad2, and Smad3 gene expression in each group under both conditions. Small interfering RNA (siRNA) was applied to inhibit Smad2/3 expression in MEPM cells and the effect was detected by western blot and flow cytometry.. The G(0)/G(1) arrest in MEPM cells in vivo was induced by atRA on GD 10. The protein expression levels of p21, Smad2/3, phospho-Smad2, and phospho-Smad3 were increased, while phospho-Rb was decreased in MEPM after atRA treatment on GD 10. These changes were not observed on the GD 12 group. Moreover, the mRNA expression levels of p21, Smad2, and Smad3 detected by quantitative real-time PCR were almost consistent with their protein expression trends. Furthermore, p21 was partially decreased and G(0)/G(1) arrest was partially released following Smad2/3 siRNA knockdown.. The induction of G(0)/G(1) block by atRA in MEPM cells varied with the development stage of exposure. Our study demonstrated that Smad2/3 regulation of p21 was partly required for atRA-induced cell cycle perturbations in MEPM cells.

Topics: Animals; Cell Cycle; Cleft Palate; Cyclin-Dependent Kinase Inhibitor p21; Disease Models, Animal; Gene Expression Regulation, Developmental; Gene Silencing; Mesoderm; Mice; Palate; RNA, Small Interfering; Smad2 Protein; Smad3 Protein; Teratogens; Tretinoin

Glioblastoma represent the most common primary brain tumor in adults and are currently considered incurable. We investigated antiproliferative and anti-invasive mechanisms of 6-OH-11-O-hydroxyfenantrene (IIF), a retinoid X receptor ligand, and pioglitazone (PGZ), a peroxisome proliferator-activated receptor gamma activator, in three different glioblastoma cell lines. A dose-dependent reduction of tumor invasion and strong decrease of matrix metalloproteinases 2 and 9 expression was observed, especially when a combination therapy of IIF and PGZ was administered. Combined treatment also markedly reduced proliferation and induced apoptosis in all glioma cell lines tested. This was in particular accompanied by decrease of antiapoptotic proteins Bcl2 and p53, while simultaneously pro-apoptotic cytochrome c, cleaved caspase 3, Bax and Bad levels increased. These in vitro findings were further substantiated in a murine glioma model in vivo, where oral administration of PGZ and IIF resulted in significantly reduced tumor volume and proliferation. Of note, treatment with nuclear receptor ligands was not only effective when the treatment was initiated shortly after the intraparenchymal seeding of the glioma cells, but even when initiated in the last third of the observation period. Collectively, our results demonstrate the effectiveness of a combined treatment of ligands of proliferator-activated receptor and retinoid X receptor against glioblastoma.

Topics: Analysis of Variance; Animals; Annexin A5; Antineoplastic Agents; bcl-2-Associated X Protein; Brain Neoplasms; Bromodeoxyuridine; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Gene Expression Regulation, Neoplastic; Glioma; Humans; Ligands; Matrix Metalloproteinases; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; Pioglitazone; PPAR gamma; Proto-Oncogene Proteins c-bcl-2; Rats; Retinoid X Receptor gamma; Tetrazolium Salts; Thiazoles; Thiazolidinediones; Transfection; Tretinoin; Tumor Stem Cell Assay

Neuroblastoma is the childhood malignancy that mainly occurs in adrenal glands and is found also in the neck, chest, abdomen, and pelvis. New therapeutic strategies are urgently needed for successful treatment of this pediatric cancer. In this investigation, we examined efficacy of the retinoid N-(4-hydroxyphenyl) retinamide (4-HPR) and the isoflavonoid genistein (GST) alone and also in combination for controlling the growth of human malignant neuroblastoma SK-N-BE2 and SH-SY5Y xenografts in nude mice. Combination of 4-HPR and GST significantly reduced tumor volume in vivo due to overwhelming apoptosis in both neuroblastoma xenografts. Time-dependently, combination of 4-HPR and GST caused reduction in body weight, tumor weight, and tumor volume. Combination of 4-HPR and GST increased Bax:Bcl-2 ratio, mitochondrial release of Smac, downregulation of baculovirus inhibitor-of-apoptosis repeat containing (BIRC) proteins including BIRC-2 and BIRC-3, and activation of caspase-3 and apoptosis inducing factor (AIF). Further, downregulation of nuclear factor-kappa B (NF-kappaB), vascular endothelial growth factor (VEGF), and fibroblast growth factor 2 (FGF2) was also detected. In situ immunofluorescent labelings of tumor sections showed overexpression of calpain, caspase-12, and caspase-3, and also AIF in the course of apoptosis. Combination therapy increased apoptosis in the xenografts but did not induce kidney and liver toxicities in the animals. Results demonstrated that combination of 4-HPR and GST induced multiple molecular mechanisms for apoptosis and thus could be highly effective for inhibiting growth of malignant neuroblastoma in preclinical animal models.

Topics: Animals; Anticarcinogenic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Apoptosis Regulatory Proteins; Body Weight; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Genistein; Humans; Intercellular Signaling Peptides and Proteins; Mice; Mice, Nude; Neuroblastoma; NF-kappa B; Transplantation, Heterologous; Treatment Outcome; Tretinoin; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Retinoic acid plays a positive role in induction of FoxP3(+) regulatory T cells. Because retinoic acid is produced as a metabolite of vitamin A in the intestine and FoxP3(+) T cells regulate intestinal inflammation, we investigated the impact of vitamin A status on the regulatory T cells and inflammation in the intestine.. The SAMP1/YP model is a mouse model of Crohn's disease. We made vitamin A-deficient, vitamin A-excessive, and normal SAMP1/YP mice and assessed the intestinal inflammation. We also investigated the phenotype and function of FoxP3(+) T cells induced in different levels of vitamin A availability in regulation of intestinal inflammation in a T-cell-induced inflammation model in SCID mice.. The limited and excessive vitamin A conditions induced distinct FoxP3(+) T-cell subsets in vivo, and both ameliorated the intestinal inflammation in SAMP1/YP mice. The limited vitamin A condition greatly induced unusual CD103(+)CCR7(+) FoxP3(+) cells, while the high vitamin A condition induced CCR9(+)alpha4beta7(+) FoxP3(+) T cells in the intestine. Both FoxP3(+) T-cell populations, when transferred into mice with ongoing intestinal inflammation, were highly effective in reversing the inflammation. Blockade or lack of occupancy of RARalpha is a mechanism to induce highly suppressive CD103(+)CCR7(+) FoxP3(+) cells in both the thymus and periphery in limited vitamin A availability.. Our results identify novel pathways of inducing highly suppressive FoxP3(+) regulatory T cells that can effectively control intestinal inflammation. The results have significant ramifications in treating inflammatory bowel diseases.

Topics: Adoptive Transfer; Animals; Anti-Inflammatory Agents; Antigens, CD; Cell Movement; Cells, Cultured; Coculture Techniques; Crohn Disease; Disease Models, Animal; Forkhead Transcription Factors; Gastrointestinal Agents; Immunophenotyping; Integrin alpha Chains; Intestines; Mice; Mice, Inbred BALB C; Mice, SCID; Receptors, CCR; Receptors, CCR7; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Spleen; T-Lymphocyte Subsets; Th1 Cells; Th2 Cells; Thymus Gland; Tretinoin; Vitamin A; Vitamin A Deficiency

Retinoids play an important role in lung development. Recently, prenatal treatment with retinoic acid (RA) has been reported to stimulate alveologenesis in hypoplastic lungs in the nitrofen model of congenital diaphragmatic hernia (CDH). Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) is a transcription factor in the steroid/thyroid hormone receptor superfamily, and targeted ablation of COUP-TFII causes CDH and associated lung hypoplasia in mice. Friend of GATA 2 (FOG2) is a zinc finger-containing protein that modulates the transcriptional activity of GATA proteins. GATA4 is a member of a family of DNA-binding proteins, which is found in the promoter regions of many genes. The COUP-TFII, FOG2, and GATA4 genes, regulated by the retinoid signaling pathway, are located on chromosomes 15q26, 8q23, and 8p23.1 respectively, regions reported to be deleted in individuals with CDH. The aim of this study was to examine the pulmonary gene expression of COUP-TFII, FOG2, and GATA4 in the nitrofen model of CDH.. Pregnant rats were exposed to either olive oil or 100 mg nitrofen on day 9 of gestation (D9). 5 mg/kg of RA was given intraperitoneally on days D18, D19, and D20. The fetuses were recovered by caesarean section on D21, and the diaphragm was carefully examined for the presence of a hernia under a microscope. Left lungs were obtained from CDH fetuses and controls and divided into four groups: control (n = 9), control + RA (n = 9), CDH (n = 9), and CDH + RA (n = 9). The relative mRNA expression levels of COUP-TFII, FOG2, and GATA4 were analyzed in each lung by real-time reverse transcriptase-polymerase chain reaction from cDNA generated by mRNA from pulmonary total RNA.. The relative mRNA expression levels of COUP-TFII, FOG2, and GATA4 were significantly increased in CDH + RA lungs compared to control, control + RA, and CDH (P < .05).. Up-regulation of pulmonary gene expression of COUP-TFII, FOG2, and GATA4 after prenatal treatment with retinoic acid in the nitrofen model of CDH suggests that RA may have a therapeutic potential in modulating lung growth. Furthermore, these results support the concept that these proteins work together to regulate downstream target genes that play an important role in the development of lung.

Topics: Animals; COUP Transcription Factor II; Disease Models, Animal; DNA-Binding Proteins; Female; GATA4 Transcription Factor; Gene Expression Regulation, Developmental; Hernia, Diaphragmatic; Humans; Lung; Mice; Phenyl Ethers; Pregnancy; Prenatal Exposure Delayed Effects; Pulmonary Alveoli; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Transcription Factors; Tretinoin; Up-Regulation

Idiopathic congenital talipes equinovarus (ICTEV) is a congenital limb deformity. Based on extended transmission disequilibrium testing, Gli-Kruppel family member 3 (Gli3) has been identified as a candidate gene for ICTEV. Here, we verify the role of Gli3 in ICTEV development.. Using the rat ICTEV model, we analyzed the differences in Gli3 expression levels between model rats and normal control rats. We used luciferase reporter gene assays and ChIP/EMSA assays to analyze the regulatory elements of Gli3.. Gli3 showed higher expression levels in ICTEV model rats compared to controls (P < 0.05). We identified repressor and activator regions in the rat Gli3 promoter. The Gli3 promoter also contains two putative Hoxd13 binding sites. Using EMSA, the Hoxd13 binding site 2 was found to directly interact with Hoxd13 in vitro. ChIP assays of the Hoxd13-Gli3 promoter complex from a developing limb confirmed that endogenous Hoxd13 interacts with this region in vivo.. Our findings suggest that HoxD13 directly interacts with the promoter of Gli3. The increase of Gli3 expression in ICTEV model animal might result from the low expression of HoxD13.

Topics: Animals; Base Sequence; Binding Sites; Cadaver; Cells, Cultured; Child; Child, Preschool; Chromatin Immunoprecipitation; Clubfoot; Disease Models, Animal; Electrophoretic Mobility Shift Assay; Female; Gene Expression Regulation, Developmental; Genes, Reporter; Hindlimb; Homeodomain Proteins; Humans; Kruppel-Like Transcription Factors; Male; Molecular Sequence Data; Nerve Tissue Proteins; Pregnancy; Promoter Regions, Genetic; Rats; Rats, Wistar; RNA, Messenger; Transcription Factors; Transfection; Tretinoin; Zinc Finger Protein Gli3

To study the effectiveness of retinoic acid on induction of osteoporotic rats treated by either alendronate or qianggu capsules and co-administration.. Sixty-five female SD rats were treated with retinoic acid 80 mg x kg(-1) x d(-1) by gastric lavage for 15 days. Then 5 rats were confirmed cases of osteoporosis and the remaining 60 were randomly divided into 4 groups 15 each: (1) control group with NS 8 ml x kg(-1) x w(-1); (2) alendronate group with alendronate 40 mg x kg(-1) x w(-1); (3) qianggu group with qianggu capsules 90 mg x kg(-1) x d(-1); (4) co-medicated group with alendronate 40 mg x kg(-1) x w(-1) and qianggu capsules 90 mg x kg(-1) x d(-1). Five rats in each group were sacrificed at week 2, 4 and 6 respectively to carry out the biomechanic tests, histopathologic examination and bony callus volume calculation.. Biomechanical properties of femur changed significantly after the treatment by alendronate or qianggu capsules and co-medication as compared with that of NS after 4 weeks (P < 0.05); the bony callus were larger when treated by alendronate (P < 0.05) and smaller by qianggu capsules (P > 0.05); the bone trabecula formed and rebuilding were slower by alendronate and quicker by qianggu capsules.. Alendronate or qianggu capsules and co-medication can improve biomechanical properties of femur by retinoic acid on induction of osteoporotic rats. Qianggu capsules can improve bone union.

Topics: Alendronate; Animals; Biomechanical Phenomena; Disease Models, Animal; Drugs, Chinese Herbal; Female; Fracture Healing; Fractures, Bone; Osteoporosis; Phytotherapy; Rats; Rats, Sprague-Dawley; Tretinoin

Therapeutic administration of retinoids is often accompanied with undesirable side effects, including an increase in lipid levels in up to 45% of treated patients. We tested the hypothesis of whether spontaneously hypertensive rat (SHR) and congenic SHR.PD-(D8Rat42-D8Arb23)/Cub (SHR-Lx) strains, differing only in a 14-gene region of chromosome 8 and previously shown to display differential sensitivity to the teratogenic effects of retinoic acid, could serve as a pharmacogenetic model set of the metabolic side effects of retinoid therapy.. Male, 15-week old rats (n = 12/strain) of SHR and SHR-Lx strains were fed a high-sucrose diet for 2 weeks and subsequently treated either with all-trans retinoic acid (15 mg/kg) or only with a vehicle for 16 days (n = 6/strain/treatment), while still on the high-sucrose diet. We assessed the morphometric and metabolic profiles of all groups, including glucose tolerance tests, levels of insulin, adiponectin, free fatty acids, concentrations of triglycerides and cholesterol in 20 lipoprotein fractions under conditions of both high-sucrose diet and high-sucrose diet plus all-trans retinoic acid administration.. SHR-Lx displayed substantially greater sensitivity to a number of all-trans retinoic acid-induced metabolic dysregulations compared with SHR, resulting in impairment of glucose tolerance, increased visceral adiposity, and substantially greater increase of circulating triglyceride concentrations, accompanied by a shift towards their less favorable distribution into the lipoprotein fractions. These observations closely mimic the common side effects of retinoid therapy in humans, rendering SHR-Lx an experimental pharmacogenetic model of atRA-induced dyslipidemia.

Topics: Animals; Animals, Congenic; Disease Models, Animal; Dyslipidemias; Glucose Tolerance Test; Hypertension; Insulin Resistance; Lipid Metabolism; Male; Pharmacogenetics; Rats; Rats, Inbred SHR; Sucrose; Tretinoin

We investigated the effect of Retinoic acid in the growth of contralateral lung after pneumonectomy.. Twenty one adult male Wistar albino rats from the same colony were used. They were divided into three groups (Group A, B and C). Group A undergone only left posterolateral thoracotomy. In Group B and C, the rats were subjected to left posterolateral thoracotomy and left pneumonectomy. In Group C, rats were given intraperitoneal Retinoic acid during the operation and continued to be given everyday postoperatively. Rats were sacrificed on the 10th day and their total body, right lung weights and right lung volumes were measured.. The volume and weight indices of the lung were found to be higher in Group C. In histopathological examination, there was a reduction in the mean number of alveoli in Group B and C. A significant rise in the mean dimension and average wall thickness of the alveolar structure were determined in Group C.. Retinoic acid contributes to the compensatory growth of the residual lung tissue.

Topics: Animals; Disease Models, Animal; Keratolytic Agents; Lung; Male; Organ Size; Pneumonectomy; Pulmonary Alveoli; Rats; Rats, Wistar; Regeneration; Treatment Outcome; Tretinoin

Retinoic acid (RA) is an active metabolite of Vitamin A, and plays an important role in the normal development of the central nervous system. Neurogranin (NG) is a brain-specific postsynaptic kinase C (PKC) substrate and calmodulin-binding protein. The effects of RA-NG interaction on ischemic brain injuries are still unclear. We investigated the effects of exogenous RA on cerebral ischemia, the involvement of NG after distal middle cerebral artery occlusion (dMCAO), and the mechanism of RA neuroprotection in rats. Focal cortical infarction was developed in the dMCAO model, followed by intraperitoneal treatment with either vehicle or RA; then the rats were evaluated with neurological deficit scores according to a beam-walking test. The infarction volume was analyzed in hematoxylin and eosin (HE)-stained sections; NG mRNA expression level was measured with a real-time PCR; and NG protein expression was determined immunohistochemically at 3, 7, 14, 21 and 28 days after dMCAO. The RA-treated rats showed a significant improvement in functional deficits and a significant decrease in infarct volume after dMCAO, compared with the vehicle group. The RA group showed an increase in NG protein or mRNA expression, compared with the vehicle group. In conclusion, administration of RA decreased the infarct volume, and promoted neurological functional recovery. This neuroprotective effect is attributed, at least in part, to NG mRNA and NG protein expression.

Topics: Analysis of Variance; Animals; Behavior, Animal; Brain Infarction; Brain Ischemia; Disease Models, Animal; Gene Expression Regulation; Male; Neurogranin; Neuroprotective Agents; Psychomotor Performance; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors; Tretinoin

Chlamydia pneumoniae, a common respiratory pathogen, has been associated with cardiovascular disease. C. pneumoniae infection accelerates atherosclerotic lesion development in hyperlipidemic animals. Retinoic acid, an anti-oxidant, inhibits infection of endothelial cells by C. pneumoniae. The present study demonstrated that retinoic acid suppresses the acceleration of foam cell lesion development induced by C. pneumoniae in hyperlipidemic C57BL/6J mice. Retinoic acid treatment had no effect on foam cell lesion development in uninfected animals. Lung infection and duration was decreased in treated mice, suggesting one mechanism by which retinoic acid reduces C. pneumoniae-accelerated foam cell lesion formation in hyperlipidemic mice.

Topics: Animals; Atherosclerosis; Chlamydophila pneumoniae; Disease Models, Animal; Foam Cells; Humans; Hyperlipidemias; Lung; Male; Mice; Mice, Inbred C57BL; Pneumonia, Bacterial; Specific Pathogen-Free Organisms; Treatment Outcome; Tretinoin

All-trans retinoic acid (RA) is a potent modulator of lung development. Chorioamnionitis, which is frequently associated with preterm birth, causes fetal lung inflammation and improves lung function but also results in alveolar simplification and microvascular injury. Endotoxin-mediated chorioamnionitis reduces RA concentration in the fetal lung to 16% of control values. We hypothesized that administration of RA to the fetus before induction of chorioamnionitis would preserve septation of the distal airspaces. Time-mated ewes with singletons were assigned to receive a fetal intramuscular treatment with 20,000 IU of RA in olive oil (or olive oil only) 3 hr prior to intra-amniotic injection of endotoxin (20 mg, E. coli 055:B5) or saline, at 124-day gestational age and 7 days after the fetal treatment. The right cranial lung lobe was processed for morphometric analysis. RA treatment did not affect chorioamnionitis-induced fetal and systemic inflammation or interleukin-8 concentrations in lung tissue. RA administration alone did not alter lung structure. Relative to control lungs (5 +/- 3 mL/kg), lung volume increased similarly with endotoxin (22 +/- 4 mL/kg) or RA plus endotoxin (20 +/- 3 mL/kg; P < 0.05). Alveolar wall thickness was 4.2 +/- 0.3 mum after endotoxin-induced chorioamnionitis, 6.0 +/- 0.4 mum in controls (P < 0.05 versus endotoxin) and 5.5 +/- 0.2 mum after RA and endotoxin (P < 0.05 versus control, n.s. versus endotoxin). The ratio of airspace versus tissue was 4.6 +/- 0.3 in endotoxin-induced chorioamnionitis, 2.1 +/- 0.3 in controls and 4.1 +/- 0.5 after RA and endotoxin. We conclude that fetal treatment with RA did not prevent inflammation-induced alveolar simplification.

Topics: Animals; Bronchopulmonary Dysplasia; Chorioamnionitis; Disease Models, Animal; Elastin; Endotoxins; Female; Fetus; Humans; Infant, Newborn; Interleukin-8; Lung; Pregnancy; Pulmonary Alveoli; Sheep; Tretinoin

Recent studies have revealed that disruption of vitamin A signaling observed in Alzheimer's disease (AD) leads to beta-amyloid (Abeta) accumulation and memory deficits in rodents. The aim of the present study was to evaluate the therapeutic effect of all-trans retinoic acid (ATRA), an active metabolite of vitamin A, on the neuropathology and deficits of spatial learning and memory in amyloid precursor protein (APP) and presenilin 1 (PS1) double-transgenic mice, a well established AD mouse model. Here we report a robust decrease in brain Abeta deposition and tau phosphorylation in the blinded study of APP/PS1 transgenic mice treated intraperitoneally for 8 weeks with ATRA (20 mg/kg, three times weekly, initiated when the mice were 5 months old). This was accompanied by a significant decrease in the APP phosphorylation and processing. The activity of cyclin-dependent kinase 5, a major kinase involved in both APP and tau phosphorylation, was markedly downregulated by ATRA treatment. The ATRA-treated APP/PS1 mice showed decreased activation of microglia and astrocytes, attenuated neuronal degeneration, and improved spatial learning and memory compared with the vehicle-treated APP/PS1 mice. These results support ATRA as an effective therapeutic agent for the prevention and treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Antineoplastic Agents; Astrocytes; Behavior, Animal; Cyclin-Dependent Kinase 5; Disease Models, Animal; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Heterogeneous-Nuclear Ribonucleoprotein U; Humans; Male; Maze Learning; Memory Disorders; Mice; Mice, Transgenic; Nerve Tissue Proteins; Presenilin-1; Reaction Time; Tretinoin

To study the effect of retinoic acid (RA) on cell proliferation and apoptosis of palatal shelves by 5-bromo-2-deoxyuridine (BrdU) and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL).. C57BL/6J mice were used to establish the RA induced cleft palate animal model, in which the pregnant mice were given a single dose of RA at 100 mg/kg body weight on gestation day 10 (GD10) and GD12, respectively. Specimens were prepared for immunohistochemical staining by using BrdU and TUNEL monoclonal antibodies.. The percentages of BrdU positive cells of embryonic palatal mesenchyme (EPM) and medial edge epithelium (MEE) in GD10 RA group were both obviously lower than that of control group. There was no difference between GD12 RA group and control group. Abnormally intense staining of TUNEL was detected in the palatal mesenchymal cells of GD10 day RA group but not in control group and GD12 day RA group.. After exposure of embryonic mice to RA on GD10, the proliferation and apoptosis of palatal mesenchymal cells are increased, this causes the smaller size of shelves and failure of fusion. The MEE cells keep a bilayer midline epithelial seam after exposure on GD12 with normal apoptosis, this indicates that cell apoptosis in MEE cells be not the only process required for palatal fusion.

Topics: Animals; Apoptosis; Cell Proliferation; Cleft Palate; Disease Models, Animal; Epithelial Cells; Epithelium; Female; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Pregnancy; Tretinoin

To further investigate the protective effect of retinoic acid (RA) on hyperoxia induced lung injury and the role of RA as a modulator on mitogen-activated protein kinases (MAPKs).. Establishment of hyperoxia (85%) induced lung injury model of premature Sprague-Dawley (SD) rats: 21 d gestational age SD rat's fetuses (term = 22 d) were delivered by hysterectomy. Within 12 - 24 h after birth, the premature rat pups were randomly divided into 4 groups: Group I, air-exposed control group; Group II, hyperoxia-exposed group; Group III, air plus RA-exposed group, Group IV, hyperoxia plus RA-exposed group. Group I and III were remained in room air, and group II and IV were placed in 85% oxygen. The pups in Group III and IV were injected with RA (500 microg/kg, every day) intraperitoneally. The entire lung tissues of premature rat pups were collected at 4 d, 7 d and 14 d. The mRNA levels of MMP-2 and MMP-9 were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). MMP-2 and MMP-9 activities were measured by zymography. Western blot was used to detect phosphorylated and total nonphosphorylated form of ERKs, JNKs and p38.. Exposure to oxygen for 4 d, 7 d, and 14 d resulted in increased mRNA levels of MMP-2 and MMP-9 compared with air-exposed control group (P < 0.01 for all). The mean protein levels of active MMP-2 and pro/active MMP-9 after exposure to O2 were higher than air control groups on each experimental day (P < 0.01 or < 0.05). The phosphorylated ERK1/2, JNK1/2 and p38 proteins in hyperoxia-exposed group increased markedly compared with air-exposed control group (P < 0.01 for all). The pups treated with RA in the hyperoxic environment expressed significantly lower mRNA levels of MMP-2 and MMP-9 than the hyperoxic control pups on each experimental day (P < 0.05 for all). The levels of active MMP-2 and pro/active MMP-9 decreased to a different degree after RA treatment in hyperoxia exposure rat pups. In addition, RA treatment led to a decrease of p-JNK1/2 and p-38 (P < 0.01 for all) protein levels and a further elevation of p-ERK1/2 compared with hyperoxia-exposed group.. Hyperoxia exposure elevated the expression of MMP-2 and MMP-9 markedly, which played a role in oxygen-induced lung injury. RA could have a protective effect on hyperoxia induced lung injury by decreasing active levels of JNK and p38, which subsequently reduce the expression and activation of MMP-2 and MMP-9.

Topics: Animals; Animals, Newborn; Disease Models, Animal; Female; Hyperoxia; Lung; Lung Injury; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mitogen-Activated Protein Kinases; Rats; Rats, Sprague-Dawley; Tretinoin

Neonatal exposure to hyperoxia alters lung development in mice. We tested if retinoic acid (RA) treatment is capable to affect lung development after hyperoxic injury and to maintain structural integrity of lung. The gene of vascular endothelial growth factor A (VEGF-A) is one of the RA-responsive genes. Newborn BALB/c mice were exposed to room air, 40% or 80% hyperoxia for 7 days. One half of animals in each group received 500 mg/kg retinoic acid from day 3 to day 7 of the experiment. At the end of experiment we assessed body weight (BW), lung wet weight (LW), the wet-to-dry lung weight ratio (W/D) and the expression of mRNA for VEGF-A and G3PDH genes. On day 7 the hyperoxia-exposed sham-treated mice (group 80) weighed 20% less than the room air-exposed group, whereas the 80% hyperoxic group treated with RA weighed only 13% less than the normoxic group. W/D values in 80 and 80A groups did not differ, although they both differed from the control group and from 40 groups. There was a significant difference between 40 and 40A groups, but the control group was different from 40 group but not from 40A groups. The 80 and 80A groups had mRNA VEGF-A expression lowered to 64% and 41% of the control group. RA treatment of normoxic and mild hyperoxic groups increased mRNA VEGF-A expression by about 50%. We conclude that the retinoic acid treatment of newborn BALB/c mice exposed for 7 days to 80% hyperoxia reduced the growth retardation in the 80 % hyperoxic group, reduced the W/D ratio in the 40% but not in the 80 % hyperoxic group. Higher VEGF-A mRNA expression in the 80% hyperoxic group treated with RA was not significant compared to the 80% hyperoxic group.

Topics: Analysis of Variance; Animals; Animals, Newborn; Antioxidants; Disease Models, Animal; Gene Expression Regulation, Developmental; Glyceraldehyde-3-Phosphate Dehydrogenases; Hyperoxia; Lung Diseases; Mice; Mice, Inbred BALB C; Pulmonary Alveoli; RNA, Messenger; Severity of Illness Index; Transcription, Genetic; Tretinoin; Vascular Endothelial Growth Factor A

Oral acitretin is currently indicated for the treatment of severe psoriasis in adults, but its use is limited by systemic side effects and teratogenicity. Topical administration of acitretin may lessen the risk of systemic toxicity while increasing local bioavailability in the skin. The effects of topical acitretin on reconstructed human epidermis (RHE) and Rhino mice were investigated and compared to those of currently marketed topical retinoids: tretinoin and tazarotene. In acitretin-treated RHE cultures, there was a reduction in keratohyalin granules and filaggrin expression in the stratum granulosum, a loss of keratin 10 expression in the stratum spinosum, and an increase in keratin 19 expression in all viable cell layers. All retinoids showed similar signs of activity in RHE cultures. Furthermore, the release of pro-inflammatory cytokines IL-1alpha and IL-8 in RHE cultures was less pronounced with acitretin compared to tretinoin- and tazarotene-containing formulations, suggesting that acitretin may be less irritating. In Rhino mice, acitretin induced a local, dose-dependent reduction in utricle diameter after seven daily dermal doses. A similar effect was observed in tretinoin- and tazarotene-treated mice. Our data suggest that topical application of acitretin may have a therapeutic benefit in the local management of keratinization disorders.

Topics: Acitretin; Administration, Topical; Animals; Disease Models, Animal; Epidermis; Female; Filaggrin Proteins; Humans; Interleukin-1alpha; Interleukin-8; Keratin-10; Keratin-19; Keratolytic Agents; Male; Mice; Mice, Hairless; Nicotinic Acids; Psoriasis; Tretinoin

MicroRNAs have been found in the developing central nervous system, but little is known about their functions in development, especially in the abnormal development of spinal cord in spina bifida. To this end, we have studied the mechanism of microRNAs involved in the morphogenesis of the spinal cord in all-trans-retinoic acid (RA)-treated spina bifida rat fetus.. Timed-pregnant rats were gavage-fed RA, and embryos were obtained on 13.5, 15.5, 17.5, and 19.5 days. MicroRNAs' expression profile was analyzed by Northern blot. In situ apoptosis detection and microRNA in situ hybridization methods on sections of paraffin-embedded tissues were employed to explore the mechanism.. Administration of RA reduced the size of the spinal cord, probably as a consequence of increased cell death. There is a dramatic decrease in the expression of miR-9/9*, miR-124a and miR-125b, and Bcl2 and P53 as well in the sacral cord from E13.5 to E19.5 days post coitum. Our data showed that expression of these microRNAs was dysregulated in RA-treated spinal cord during embryonic development, suggesting that they may be involved in the development of the spinal cord.

Topics: Animals; Antineoplastic Agents; Disease Models, Animal; Down-Regulation; Embryo, Mammalian; Female; Gene Expression Regulation, Developmental; Male; MicroRNAs; Pregnancy; Rats; Rats, Sprague-Dawley; Spinal Cord; Spinal Dysraphism; Tretinoin

The mouse model of 2,4,6-Trinitrobenzene Sulfonic Acid (TNBS)-induced intestinal fibrosis allows for detailed study of the extracellular matrix changes that complicate Crohn's disease. Indomethacin induces intestinal fibrosis, while retinoic acid (RA) reduces liver fibrosis. Secreted protein acidic and rich in cysteine (SPARC), an extracellular matrix-modifying agent, may potentially link these opposing effects. Our aim was to determine the effects of indomethacin and RA and to evaluate their correlation to SPARC expression in the TNBS mouse model. CD-1 mice were randomised to TNBS enemas weekly for 2 or 8 weeks with or without indomethacin (0.2 mg/kg per day) or RA (100 microg/kg per day). At 2 weeks, indomethacin/TNBS enhanced and RA reduced inflammation, tissue destruction and fibrosis. The expression of SPARC was inversely related to fibrosis, but not to inflammation, in the TNBS-alone groups at 2 weeks; these differences were lost by 8 weeks. The results demonstrate that indomethacin increases TNBS-induced fibrosis in mice, while RA reduces it, and that SPARC may link these opposing effects.

Topics: Animals; Crohn Disease; Disease Models, Animal; Female; Fibrosis; Immunoenzyme Techniques; Indomethacin; Mice; Osteonectin; Random Allocation; Reverse Transcriptase Polymerase Chain Reaction; RNA; Statistics, Nonparametric; Tretinoin; Trinitrobenzenesulfonic Acid

Holoprosencephaly (HPE) is the most common human congenital forebrain defect, affecting specification of forebrain tissue and subsequent division of the cerebral hemispheres. The causes of HPE are multivariate and heterogeneous, and include exposure to teratogens, such as retinoic acid (RA), and mutations in forebrain patterning genes. Many of the defects in HPE patients resemble animal models with aberrant RA levels, which also show severe forebrain abnormalities. RA plays an important role in early neural patterning of the vertebrate embryo: expression of RA-synthesizing enzymes initiates high RA levels in the trunk, which are required for proper anterior-posterior patterning of the hindbrain and spinal cord. In the forebrain and midbrain, RA-degrading enzymes are expressed, protecting these regions from the effects of RA. However, the mechanisms that regulate RA-synthesizing and RA-degrading enzymes are poorly understood. Mutations in the gene TGIF are associated with incidence of HPE. We demonstrate in zebrafish that Tgif plays a key role in regulating RA signaling, and is essential to properly pattern the forebrain. Tgif is necessary for normal initiation of genes that control RA synthesis and degradation, resulting in defects in RA-dependent central nervous system patterning in Tgif-depleted embryos. The loss of the forebrain-specific RA-degrading enzyme cyp26a1 causes a forebrain phenotype that mimics tgif morphants. We propose a model in which Tgif controls forebrain patterning by regulating RA degradation. The consequences of abnormal RA levels for forebrain patterning are profound, and imply that in human patients with TGIF deficiencies, increased forebrain RA levels contribute to the development of HPE.

Topics: Animals; Base Sequence; Body Patterning; Cytochrome P-450 Enzyme System; Disease Models, Animal; DNA, Complementary; Gene Expression Regulation, Developmental; Genes, Homeobox; Holoprosencephaly; Homeodomain Proteins; Humans; Oligodeoxyribonucleotides, Antisense; Phenotype; Prosencephalon; Repressor Proteins; Retinoic Acid 4-Hydroxylase; Rhombencephalon; Signal Transduction; Tretinoin; Zebrafish; Zebrafish Proteins

Intestinal fibrosis leading to severe bowel dysmobility or obstruction is a troublesome adverse effect of abdominal or pelvic radiation therapy. We have recently reported that all-trans-retinoic acid (ATRA) prevents radiation- or bleomycin-induced lung fibrosis. Here, we examined the impact of ATRA on the mouse model of radiation-induced intestinal fibrosis.. We evaluated the histology of late radiation fibrosis in surgical samples. We then performed histological examinations and quantitative measurements of mRNA of interleukin-6 and transforming growth factor-beta(1) in intestinal tissues of irradiated mice with or without intraperitoneal administration of ATRA and investigated the effect of ATRA on the transdifferentiation and the production of collagen of irradiated human intestinal fibroblasts.. Human samples of late radiation enteritis showed thickened submucosa and serosa, consistent with mouse model. Administration of ATRA attenuated irradiation-induced intestinal fibrosis and reduced mRNA of interleukin-6 and transforming growth factor-beta(1). In vitro studies disclosed that ATRA suppressed the transdifferentiation of irradiated intestinal fibroblasts and diminished the production of collagen from the cells.. Our findings indicate that ATRA ameliorates irradiation-induced intestinal fibrosis. ATRA could be a novel approach in the treatment of fibrosis associated with chronic radiation enteritis.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Agents; Cell Line; Cell Transdifferentiation; Disease Models, Animal; Enteritis; Female; Fibroblasts; Fibrosis; Humans; Interleukin-6; Intestine, Small; Male; Mice; Mice, Inbred C57BL; Middle Aged; Radiotherapy; RNA, Messenger; Transforming Growth Factor beta1; Tretinoin

Retinoids play an important role in lung development. A recent study has demonstrated that prenatal treatment with retinoic acid (RA) stimulates alveologenesis in hypoplastic lungs in the nitrofen model of congenital diaphragmatic hernia (CDH). Furthermore, it has also been demonstrated that the differentiation from alveolar epithelial cells type II (AECs-II) into alveolar epithelial cells type I (AECs-I), which is the key process in lung development, is disturbed in this model. We hypothesized that retinoids promote alveologenesis by stimulating differentiation of AECs-II to AECs-I at the end of gestation; and therefore, we investigated the effect of RA on the pulmonary expression of intercellular adhesion molecule 1 (ICAM-1), a marker for AECs-I, and thyroid transcription factor 1 (Ttf-1), a marker for AECs-II, in nitrofen-induced hypoplastic lungs.. Pregnant rats were exposed to either olive oil or 100 mg nitrofen on day of gestation (D) 9. Five milligrams per kilogram of RA was given intraperitoneally on D18, D19, and D20; and fetuses were recovered on D21. We had 4 study groups: control (n = 7), control + RA (n = 7), CDH (n = 6), and CDH + RA (n = 6). The expression of ICAM-1 and Ttf-1 was analysed in each lung by real-time reverse transcription polymerase chain reaction and immunohistochemistry. One-way analysis of variance test was used for statistical analysis.. Expression levels of ICAM-1 were significantly reduced in CDH lungs compared with normal controls, whereas levels increased significantly in CDH group after the addition of RA (P < .05). Expression levels of Ttf-1 were significantly decreased in lungs from RA-treated CDH animals compared with CDH without RA (P < .05). The ICAM-1 and Ttf-1 immunoreactivity demonstrated similar pattern of expression in various groups.. Our results demonstrate that prenatal treatment with RA accelerates AEC-I proliferation in the hypoplastic lung in CDH.

Topics: Animals; Cell Proliferation; Disease Models, Animal; Drug Administration Schedule; Epithelial Cells; Female; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Immunohistochemistry; Lung; Phenyl Ethers; Pregnancy; Pregnancy, Animal; Prenatal Care; Probability; Pulmonary Alveoli; Random Allocation; Rats; Rats, Sprague-Dawley; Reference Values; Respiratory System Abnormalities; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sensitivity and Specificity; Tretinoin

The cellular uptake of vitamin A from its RBP4-bound circulating form (holo-RBP4) is a homeostatic process that evidently depends on the multidomain membrane protein STRA6. In humans, mutations in STRA6 are associated with Matthew-Wood syndrome, manifested by multisystem developmental malformations. Here we addressed the metabolic basis of this inherited disease. STRA6-dependent transfer of retinol from RBP4 into cultured NIH 3T3 fibroblasts was enhanced by lecithin:retinol acyltransferase (LRAT). The retinol transfer was bidirectional, strongly suggesting that STRA6 acts as a retinol channel/transporter. Loss-of-function analysis in zebrafish embryos revealed that Stra6 deficiency caused vitamin A deprivation of the developing eyes. We provide evidence that, in the absence of Stra6, holo-Rbp4 provokes nonspecific vitamin A excess in several embryonic tissues, impairing retinoic acid receptor signaling and gene regulation. These fatal consequences of Stra6 deficiency, including craniofacial and cardiac defects and microphthalmia, were largely alleviated by reducing embryonic Rbp4 levels by morpholino oligonucleotide or pharmacological treatments.

Topics: Abnormalities, Multiple; Acyltransferases; Animals; Cardiovascular Abnormalities; Craniofacial Abnormalities; Disease Models, Animal; Eye; Gene Deletion; Gene Expression Regulation, Developmental; Homeostasis; Humans; Membrane Proteins; Membrane Transport Proteins; Mice; Morpholines; NIH 3T3 Cells; Oligonucleotides, Antisense; Retinol-Binding Proteins, Plasma; Syndrome; Time Factors; Transduction, Genetic; Tretinoin; Vitamin A; Zebrafish; Zebrafish Proteins

Vitamin A plays an essential role in vertebrate embryogenesis. In the present study, pregnant vitamin A-deficient (VAD) rats were maintained during early pregnancy on the short half-life vitamin A metabolite, all-trans retinoic acid (atRA), in an amount sufficient to support normal development to E10.5, with a higher level of atRA (250 microg atRA/g diet) provided from embryonic day (E) 8.5-10.5 to prevent mid-gestational resorption. When limiting amounts of atRA (1.5 or 12 microg/g diet) were provided after E10.5, a highly reproducible and penetrant state of late fetal vitamin A deficiency (late VAD) was induced in the organs of developing fetuses. In addition, late VAD fetuses displayed both anteriorization of cervical regions and novel posteriorization events at the thoracic and sacral levels of the skeleton, and showed sternal and pelvic malformations not previously observed in early VAD or genetic models. The expression of several Hox genes (Hoxd3 and Hoxb4) was altered in late VAD embryos, with a reduction in Hoxd3 noted as early as 1 day after instituting deficiency. All late VAD-induced malformations were prevented by the addition of retinol starting at E10.5, whereas provision of a high level of atRA throughout pregnancy improved but could not completely rescue the development of all organ systems. This work defines a nutritional model in which vitamin A deficiency can be induced during fetal development, and reveals new functions for the vitamin in the development of the axial and appendicular skeleton.

Topics: Animal Nutritional Physiological Phenomena; Animals; Bone Development; Disease Models, Animal; Fetal Development; Gastrula; In Situ Hybridization; Organogenesis; Rats; Rats, Sprague-Dawley; Tretinoin; Vitamin A Deficiency

In this study the gastric mucosa of transgenic mice expressing the simian virus 40 large T antigen gene in the parietal cell lineage is used to establish and characterize a new epithelial progenitor cell line. In these mice, proliferation and amplification of preparietal cells preclude their maturation into acid-secreting parietal cells leading to achlorohydria, hyperplasia, dysplasia and eventually gastric adenocarcinoma.. Enzymatically dispersed gastric epithelial cells were cultured, cloned and screened using immunohistochemical methods, for expression of a variety of biomarkers of differentiated pit, parietal, enteroendocrine and neck/zymogenic cells.. A biomarker-deficient cell line whose ultrastructural features resembled those of mouse gastric epithelial progenitor cells was established. Treatment with either hydrocortisone or oestrogen significantly enhanced proliferation of these cells, whereas retinoic acid inhibited their growth. No change in differentiation was detected with any of these treatments; however, when these cells were injected subcutaneously into nude mice, they proliferated to form tumours and undergo partial differentiation towards parietal cell lineage.. This mouse gastric epithelial progenitor cell line could be useful as an in vitro model to study growth properties, proliferation and differentiation of a subpopulation of gastric epithelial progenitor cells and also to study gastric carcinogenesis.

Topics: Animals; Antigens, Polyomavirus Transforming; Biomarkers; Cell Differentiation; Cell Line; Cell Lineage; Cell Proliferation; Disease Models, Animal; Epithelial Cells; Estrogens; Female; Gastric Mucosa; Hydrocortisone; Mice; Mice, Inbred Strains; Mice, Nude; Mice, Transgenic; Parietal Cells, Gastric; Stem Cells; Tretinoin

Severe pulmonary hypoplasia remains the main cause of the high mortality in newborn infants with congenital diaphragmatic hernia (CDH). Retinoids are a family of molecules derived from vitamin A, which play an important role in lung development. We hypothesized that retinoids promote alveologenesis at the end of gestation and therefore designed this study to investigate the effects of retinoid acid on nitrofen-induced hypoplastic lungs in CDH.. Pregnant rats were exposed to either olive oil or 100 mg nitrofen on day 9 of gestation. Retinoic acid 5 mg/kg was given intraperitoneally on days 18, 19, and 20 of gestation and fetuses were recovered on day 21. We had 4 study groups: control (n = 24), control + retinoic acid (n = 22), CDH (n = 24), and CDH + retinoic acid (n = 19). Lungs from the 4 study groups were fixed, and the following stereological measurements were performed on vertical random sections: total lung volume, volume density of airspaces, volume density of air walls, gas exchange surface area, alveolar volume, and total number of alveoli per lung. Total DNA content of each lung was measured using a spectrophotometer.. Total lung volume increased in CDH lungs after the addition of retinoic acid but remained the same in the control group. Gas exchange surface area was larger in CDH lungs after the addition of retinoic acid but remained unchanged in the control group. The total number of alveoli per lung was higher after the addition of retinoic acid. Total DNA content as well as total DNA content-lung weight ratio of the left lung increased significantly in the CDH group after the addition of retinoic acid compared with CDH without retinoic acid.. Our results demonstrate that prenatal treatment with retinoic acid stimulates alveologenesis in hypoplastic lungs in CDH.

Topics: Animals; Disease Models, Animal; Female; Fetal Organ Maturity; Hernias, Diaphragmatic, Congenital; Injections, Intraperitoneal; Lung; Phenyl Ethers; Pregnancy; Pregnancy, Animal; Prenatal Care; Probability; Pulmonary Alveoli; Random Allocation; Rats; Rats, Sprague-Dawley; Reference Values; Respiratory System Abnormalities; Sensitivity and Specificity; Tretinoin

Retinoic acid (RA) displays potent anticarcinogenic activities that are mediated by the nuclear retinoic acid receptors (RARs). However, use of RA in oncology is limited by RA resistance acquired during carcinogenesis. Moreover, in some cancers, RA facilitates rather than inhibits growth. A clue to this paradoxical behavior was recently suggested by the findings that RA also activates PPARbeta/delta, a receptor involved in mitogenic and anti-apoptotic activities. The observations that partitioning of RA between its two receptors is regulated by two intracellular lipid-binding proteins-CRABP-II, which targets RA to RAR, and FABP5, which delivers it to PPARbeta/delta-further suggest that RA resistance may stem from the deregulation of the binding proteins, resulting in activation of PPARbeta/delta rather than RAR. Here, we show that, in the RA-resistant mouse model of breast cancer MMTV-neu, RA indeed activates the nonclassical RA receptor PPARbeta/delta. This behavior was traced to an aberrantly high intratumor FABP5/CRABP-II ratio. Decreasing this ratio in mammary tissue diverted RA from PPARbeta/delta to RAR and suppressed tumor growth. The data demonstrate the existence of a mechanism that underlies RA resistance in tumors, indicate that CRABP-II functions as a tumor suppressor, and suggest that the inhibition of FABP5 may comprise a therapeutic strategy for overcoming RA resistance in some tumors.

Topics: Animals; Antineoplastic Agents; Carcinoma; Cell Line, Tumor; Disease Models, Animal; Drug Resistance, Neoplasm; Fatty Acid-Binding Proteins; Mammary Neoplasms, Animal; Mice; Mice, Transgenic; Neoplasm Proteins; PPAR delta; PPAR-beta; Receptors, Retinoic Acid; Transcription, Genetic; Tretinoin

The role of retinoic acid (RA) in liver fibrogenesis was previously studied in cultured hepatic stellate cells (HSCs). RA suppresses the expression of alpha2(I) collagen by means of the activities of specific nuclear receptors RARalpha, RXRbeta and their coregulators. In this study, the effects of RA in fibrogenesis were examined in carbon tetrachloride (CCl4) induced liver fibrosis in mice. Mice were treated with CCl4 or RA and CCl4, along side control groups, for 12weeks. RA reduced the amount of histologically detectable fibrosis produced by CCl4. This was accompanied by a attenuation of the CCl4 induced increase in alpha2(I) collagen mRNA and a lower (2-fold versus 3-fold) increase in liver hydroxyproline. Furthermore, RA reduced the levels of 3-nitrotyrosine (3-NT) protein adducts and thiobarbituric acid (TBA) reactive substance (TBARS) in the liver, which are formed as results of oxidative stress induced by CCl4 treatment. These in vivo findings support our previous in vitro studies in cultured HSC of the inhibitory effect of RA on type I collagen expression. The data also provide evidence that RA reduces CCl4 induced oxidative stress in liver, suggesting that the anti-fibrotic role of RA is not limited to the inhibition of type I collagen expression.

Topics: Animals; Collagen Type I; Disease Models, Animal; Gene Expression; Hydroxyproline; Liver Cirrhosis, Experimental; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Thiobarbituric Acid Reactive Substances; Tretinoin

Near-infrared reflectance confocal microscopy (RCM) is a noninvasive tool that provides real-time images of thin virtual horizontal tissue sections.. We have used a rhino mouse model in combination with topical application of all-trans-retinoic acid and all-trans-retinol to investigate the usefulness of RCM as a noninvasive imaging tool to evaluate comedolysis in vivo and over time. Optical images were correlated with routine histology.. Our results demonstrate that RCM in vivo can visualize the process of transformation of utriculi (pseudocomedones) towards a normal-appearing follicular structure during retinoid treatment. The retinoic acid intervention group showed a dose-related response, while the vehicle-treated group did not show utricular changes.. RCM represents a useful tool for in vivo morphological and quantitative evaluation of skin utriculi over time and could be used as an adjunct tool to histopathological techniques for comedolysis studies.

Topics: Acne Vulgaris; Animals; Disease Models, Animal; Mice; Microscopy, Confocal; Tretinoin; Vitamin A

Retinoic acid (RA), a principal metabolite of vitamin A (retinol), is an essential endogenous regulator of gene transcription and an important therapeutic agent. The catabolism of RA must be well regulated to maintain physiological concentrations of RA. The cytochrome P450 (CYP) gene family CYP26, which encodes RA-4-hydroxylase activity, is strongly implicated in the oxidation of RA. Inflammation alters the expression of numerous genes; however, whether inflammation affects CYP26 expression is not well understood. We investigated the regulation of CYP26A1 and CYP26B1 mRNA levels by RA and LPS in the rat liver, as the liver is centrally involved in retinoid metabolism and the acute-phase response to LPS. Both CYP26A1 and CYP26B1 mRNA were induced in <4 h by a single oral dose of all-trans-RA. RA-induced responses of both CYP26A1 and CYP26B1 were significantly attenuated in rats with LPS-induced inflammation whether LPS was given concurrently with RA or after the RA-induced increase in CYP26A1 and CYP26B1 mRNA levels. When RA and LPS were administered simultaneously (6-h study), LPS alone had little effect on either CYP26A1 or CP26B1 mRNA, but LPS reduced by 80% the RA-induced increase in CYP26A1 mRNA (P<0.02), with a similar trend for CYP26B1 mRNA. When LPS was administered 4 h after RA (16-h study), it abrogated the induction of CYP26A1 (P<0.02) and CYP26B1 (P<0.01). Overall, these results suggest that inflammation can potentially disrupt the balance of RA metabolism and maintenance of RA homeostasis, which may possibly affect the expression of other RA-regulated genes.

Topics: Animals; Cytochrome P-450 Enzyme System; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Induction; Female; Inflammation; Isoenzymes; Lipopolysaccharides; Liver; Poly I-C; Rats; Rats, Sprague-Dawley; Retinoic Acid 4-Hydroxylase; RNA, Messenger; Time Factors; Toll-Like Receptor 3; Transcription, Genetic; Tretinoin

Retinoids are a group of molecules derived from vitamin A, which play an important role in lung development. Within the cell, retinol can either be oxidized to retinal or esterified to retinyl esters by lecithin : retinol acyltransferase (LRAT) for storage. Retinal is then oxidized to an active metabolite of vitamin A, retinoic acid (RA) by retinal dehydrogenase (RALDH). RA is the active metabolite of vitamin A. Cyp26 (a1,b1, and c1), which is a member of the cytochrome P450 family, acts by reducing the activity of RA. Cyp26 type b1 is the predominant subtype expressed in the murine lung. Several studies have suggested that nitrofen may interfere with the retinoid pathway resulting in congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia. Recently, it was reported that nitrofen may act by inhibiting RALDH2. The aim of this study was to examine the pulmonary expression of Cyp26b1, LRAT, and RALDH2, the key enzymes involved in the synthesis of RA, in order to understand the mechanisms underlying pulmonary hypoplasia in the nitrofen CDH model. Pregnant rats were exposed to either olive oil or 100 mg of nitrofen on day 9 of gestation (D9). Fetal lungs were harvested at D15, D17, D19, and D21. D17, D19, and D21 lungs were divided into three groups: control, nitrofen without CDH and nitrofen with CDH, whereas D15 lungs were divided into only two groups; control and nitrofen as the diaphragm is not fully formed yet at this stage. Real- time PCR was performed to evaluate the relative level of Cyp26b1, LRAT, and RALDH2 expression in the lung. Relative levels of Cyp26b1 mRNA were significantly decreased in the lungs of nitrofen with CDH (D17;0.19 +/- 0.09, D19;0.70 +/- 0.20, D21;0.40 +/- 0.36) and nitrofen without CDH (D17;0.14 +/- 0.06, D19;0.54 +/- 0.42, D21;0.51 +/- 0.56) compared to controls (D17;0.35 +/- 0.16, D19;1.15 +/- 0.48, D21;1.28 +/- 0.78) (P < 0.05). LRAT expression was also significantly decreased in nitrofen with CDH (D17; 19.3 +/- 7.8, D19; 4.3 +/- 1.1, D21; 3.3 +/- 1.6) and nitrofen without CDH (D17; 21.2 +/- 11.1, D19; 4.5 +/- 3.6, D21; 4.1 +/- 1.6) compared to controls (D17; 153.7 +/- 29.8, D19; 26.8 +/- 16.8 D21; 10.1 +/- 3.8) (P < 0.05). There was no significant difference in the relative levels of Cyp26b1 and LRAT between nitrofen with CDH and nitrofen without CDH. There were no significant differences in RALDH2 expression among the groups at any stages. Down-regulation of Cryp26b1 and LRAT demonstrates that RA content is decreased i

Topics: Acyltransferases; Animals; Cytochrome P-450 Enzyme System; Disease Models, Animal; Down-Regulation; Female; Gene Expression Regulation, Developmental; Herbicides; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Lung; Lung Diseases; Olive Oil; Phenyl Ethers; Plant Oils; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Retinal Dehydrogenase; Retinoic Acid 4-Hydroxylase; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin

9-cis-Retinoic acid (9cRA) and 1alpha,25-dihydroxyvitamin D3 (1,25D) show promise as potential chemopreventive agents. We examined 9cRA and 1,25D, alone and in combination, for their potential to inhibit carcinogen (NNK)-induced lung carcinogenesis in A/J mice. A/J mice (n=14/group) were treated with 9cRA (7.5, 15, or 30 mg/kg diet), 1,25D (2.5 or 5.0 microg/kg diet), or a combination of 9cRA (15 mg/kg diet) plus 1,25D (2.5 microg/kg diet) for 3 weeks before and 17 weeks after carcinogen injection. Lung tumor incidence, tumor multiplicity, plasma 1,25D levels and kidney expression of vitamin D 24-hydroxylase (CYP24) were determined. Compared to carcinogen-injected controls, mice receiving 9cRA supplementation had significantly lower tumor multiplicity at all doses (decreased 68-85%), with body weight loss at the higher doses of 9cRA. Mice receiving 1,25D supplementation had significantly lower tumor incidence (decreased 36 and 82%) and tumor multiplicity (decreased 85 and 98%), but experienced significant body weight loss, kidney calcium deposition, elevated kidney CYP24 expression and decreased fasting plasma 1,25D levels. Although, there was no apparent influence on chemopreventive efficacy, addition of 9cRA to 1,25D treatment effectively prevented the weight loss and kidney calcification associated with 1,25D treatment alone. These data demonstrate that 9cRA and 1,25D, alone or combined, can inhibit lung tumor promotion in the A/J mouse model. Combining 1,25D with 9cRA has the potential to mitigate the toxicity of 1,25D, while preserving the significant effect of 1,25D treatment against lung carcinogenesis. The underlying mechanism behind this effect does not appear to be related to retinoid modulation of vitamin D catabolism.

Topics: Adenoma; Alitretinoin; Animals; Antineoplastic Agents; Calcitriol; Carcinogens; Cell Transformation, Neoplastic; Dietary Supplements; Disease Models, Animal; Drug Therapy, Combination; Lung Neoplasms; Male; Mice; Mice, Inbred A; Nitrosamines; Retinoid X Receptors; Steroid Hydroxylases; Tretinoin; Vitamin D3 24-Hydroxylase; Vitamins

Mercuric chloride (HgCl2) induces an autoimmune nephritis in the Brown Norway (BN) rats characterized by anti-glomerular basement membrane antibodies (anti-GBM Ab) deposition, proteinuria and a severe interstitial nephritis, all evident at day 13 of the disease. We assessed the effects of all-trans retinoic acid (at-RA) in this experimental model. At-RA is a vitamin A metabolite which has shown beneficial effects on several nephropathies, even though no clear targets for at-RA were provided.. We separated animals in four different experimental groups (HgCl2, HgCl2+at-RA, at-RA and vehicle). From each animal we collected, at days 0 and 13, numerous biological samples: urine, to measure proteinuria by colorimetry; blood to determine VLA-4 expression by flow citometry; renal tissue to study the expression of VCAM-1 by Western blot, the presence of cellular infiltrates by immunohistochemistry, the IgG deposition by immunofluorescence, and the cytokines expression by RT-PCR. Additionally, adhesion assays to VCAM-1 were performed using K562 alpha4 transfectant cells. ANOVA tests were used for statistical significance estimation.. We found that at-RA significantly decreased the serum levels of anti-GBM and consequently its deposition along the glomerular membrane. At-RA markedly reduced proteinuria as well as the number of cellular infiltrates in the renal interstitium, the levels of TNF-alpha and IL-1beta cytokines and VCAM-1 expression in renal tissue. Moreover, we reported here for the first time in an in vivo model that at-RA reduced, to basal levels, the expression of VLA-4 (alpha4beta1) integrin induced by mercury on peripheral blood leukocytes (PBLs). In addition, using K562 alpha4 stable transfectant cells, we found that at-RA inhibited VLA-4 dependent cell adhesion to VCAM-1.. Here we demonstrate a therapeutic effect of at-RA on an autoimmune experimental nephritis model in rats. We report a significant reduction of the VLA-4 integrin expression on PBLs as well as the inhibition of the VLA4/VCAM1-dependent leukocyte adhesion by at-RA treatment. Thereby we point out the VLA-4 integrin as a target for at-RA in vivo.

Topics: Animals; Autoimmune Diseases; Disease Models, Animal; Dose-Response Relationship, Drug; Immunity, Innate; Immunosuppressive Agents; Integrin alpha4beta1; Male; Mercuric Chloride; Nephritis; Rats; Treatment Outcome; Tretinoin

The mechanisms of prevention of the development of liver cancer by NIK-333, an acyclic retinoid (ACR), were investigated. The transgenic mice expressing the dominant negative form of retinoic acid receptor alpha (RARE mice), that produce reactive oxygen species and lead to development of liver tumor were used. The effect of NIK-333 on hepatocarcinogenesis in RARE mice was studied. The RARE mice were examined after feeding 0.03% and 0.06% NIK-333 diets at 12 months of age. In the mice fed 0.06% NIK-333 diet, tumor incidence was greatly suppressed, compared to that of wild type mice (0/9 versus 5/9, P<0.05), but not in the mice fed 0.03% NIK-333 diet. In addition, expression of cytochrome p450 4a14 and acyl-CoA oxidase was normalized, and the percentages of positive cells for 8-hydroxy-2'-deoxyguanosine, 4-hydroxy-2-nonenal and proliferating cell nuclear antigen were decreased. Furthermore, expression of beta-catenin and cyclin D1 was also depressed. These data suggest that NIK-333 suppressed liver tumor in association with repression of oxidative stress.

Topics: Animals; Antioxidants; Disease Models, Animal; Liver Neoplasms; Mice; Mice, Transgenic; Neoplasm Transplantation; Oxidative Stress; Tretinoin; Xenograft Model Antitumor Assays

Cardiovascular events are accelerated in chronic kidney disease (CKD). Although deranged nitric oxide (NO) pathways and asymmetric dimethylarginine (ADMA) cause endothelial dysfunction, no direct evidence for coronary artery endothelial dysfunction in CKD has been documented. CKD was induced in male dogs by heminephrectomy (1/2Nx) or five-sixths nephrectomy (5/6Nx). After 4 wk, renal ablation reduced GFR (control 76 [54 to 85]; 1/2Nx 38 [29 to 47]; 5/6Nx 15 [12 to 46] ml/min) and elevated plasma ADMA (control 1.88 [1.68 to 2.54]; 1/2Nx 2.51 [2.11 to 3.55]; 5/6Nx 3.84 [2.16 to 3.95] micromol/L). Coronary circulatory responses to acetylcholine revealed marked increases in coronary blood flow in control group (83 +/- 17% increment) but blunted responses in 1/2Nx (34 +/- 8% increment) and 5/6Nx (20 +/- 4% increment). The acetylcholine-induced changes in epicardial arteriolar diameter, using needle-lens probe charge-coupled device videomicroscopy, showed similar results. The responsiveness to sodium nitroprusside did not differ among three groups. Plasma nitrite/nitrate levels decreased in 1/2Nx and 5/6Nx, and the mRNA expressions of dimethylarginine dimethylaminohydrolase-II (DDAH-II), ADMA-degrading enzyme, and endothelial NO synthase (eNOS) in coronary arteries were downregulated in 1/2Nx and 5/6Nx. Finally, 4-wk treatment with all-trans retinoic acid restored the impaired endothelium-dependent vasodilation and reversed the expression of eNOS but not DDAH-II. Coronary endothelial function is impaired in the early stage of CKD. The dysfunction is attributed to the downregulation of eNOS and/or DDAH-II in coronary arteries. Furthermore, the manipulation of NO pathways may constitute a therapeutic strategy for the prevention of coronary dysfunction in CKD.

Topics: Acetylcholine; Amidohydrolases; Animals; Arginine; Coronary Circulation; Disease Models, Animal; Dogs; Endothelium-Dependent Relaxing Factors; Endothelium, Vascular; Glomerular Filtration Rate; Kidney Failure, Chronic; Male; Microscopy, Video; Nitric Oxide; Nitric Oxide Synthase Type III; Nitroprusside; Tretinoin; Vasodilation; Vasodilator Agents

Following the loss of functional small bowel surface area, the intestine undergoes a compensatory adaptive response. The observation that adaptation is inhibited in vitamin A-deficient rats following submassive intestinal resection suggested that vitamin A is required for this response and raised the possibility that exogenous vitamin A could augment adaptation. Therefore, to directly assess whether chronically administered retinoic acid could stimulate gut adaptation in a model of short bowel syndrome and to address the mechanisms of any such effects, Sprague-Dawley rats were implanted with controlled release retinoic acid or control pellets and then subjected to mid-small bowel or sham resections. At 2 wk postoperation, changes in gut morphology, crypt cell proliferation and apoptosis, enterocyte migration, the extracellular matrix, and gene expression were assessed. Retinoic acid had significant trophic effects in resected and sham-resected rats. Retinoic acid markedly inhibited apoptosis and stimulated crypt cell proliferation and enterocyte migration postresection. Data presented indicate that these proadaptive effects of retinoic acid may be mediated via changes in the extracellular matrix (e.g., by increasing collagen IV synthesis, decreasing E-cadherin expression, and reducing integrin beta(3) levels), via affects on Hedgehog signaling (e.g., by reducing expression of the Hedgehog receptors Ptch and Ptch2 and the Gli1 transcription factor), by increasing expression of Reg1 and Pap1, and by modulation of retinoid and peroxisome proliferator-activated receptor signaling pathways. These studies are the first to demonstrate that retinoic acid can significantly enhance intestinal adaptation and suggest it may be beneficial in patients with short bowel syndrome.

Topics: Adaptation, Physiological; Animals; Apoptosis; beta Catenin; Cell Movement; Cell Proliferation; Disease Models, Animal; Drug Implants; Enterocytes; Extracellular Matrix Proteins; Gene Expression; Hedgehog Proteins; Intestine, Small; Male; Pancreatitis-Associated Proteins; Peroxisome Proliferator-Activated Receptors; Rats; Rats, Sprague-Dawley; Receptors, Retinoic Acid; RNA, Messenger; Short Bowel Syndrome; Signal Transduction; Time Factors; Tretinoin; Wnt Proteins

Nurr1 has been implicated as a transcription factor mediating the endogenous neuroprotective mechanism against stroke. We examined the in vivo and in vitro properties of a new human embryonic carcinoma Ntera-2 cell line carrying the human Nurr1 gene (NT2N.Nurr1). Adult Sprague-Dawley rats underwent experimental stroke initially and 14 days later were assigned randomly to receive stereotaxic transplantation of NT2N.Nurr1 cells or infusion of vehicle into their ischemic striatum. Transplantation of NT2N.Nurr1 cells promoted significant attenuation of behavioral impairments over a 56-day period after stroke, characterized by decreased hyperactivity, biased swing activity, and neurologic deficits, as well as significant reduction in ischemic striatal cell loss compared to vehicle-infused stroke animals. Transplanted NT2N.Nurr1 cells survived and expressed neuronal phenotypic markers in the ischemic striatum. In vitro results showed that cultured NT2.Nurr1 cells were already negative for nestin even before retinoic acid treatment, despite strong nestin immunoreactivity in NT2 cells. This indicates Nurr1 triggered a rapid commitment of NT2 cells into a neuronal lineage. Indeed, NT2.Nurr1 cells, at 4 weeks into RA treatment, displayed more abundant tyrosine hydroxylase positive cells than NT2 cells. Parallel ELISA studies showed further that cultured NT2N.Nurr1, but not NT2N cells, secreted glial cell derived neurotrophic factor. The present study shows efficacy of NT2N.Nurr1 cell grafts in ischemic stroke, with in vitro evidence suggesting the cells' excellent neuronal differentiation capability and ability to secrete GDNF as likely mechanisms mediating the observed therapeutic benefits.

Topics: Animals; Behavior, Animal; Carcinoma; Cell Differentiation; Cell Line, Tumor; Cell Transplantation; Corpus Striatum; Disease Models, Animal; DNA-Binding Proteins; Enzyme-Linked Immunosorbent Assay; Glial Cell Line-Derived Neurotrophic Factor; Humans; Male; Motor Activity; Multivariate Analysis; Nerve Tissue Proteins; Nuclear Receptor Subfamily 4, Group A, Member 2; Rats; Rats, Sprague-Dawley; Stroke; Time Factors; Transcription Factors; Tretinoin

Congenital diaphragmatic hernia (CDH) is a congenital malformation that occurs with a frequency of 0.08 to 0.45 per 1,000 births. Children with CDH are born with the abdominal contents herniated through the diaphragm and exhibit an associated pulmonary hypoplasia which is frequently accompanied by severe morbidity and mortality. Although the etiology of CDH is largely unknown, considerable progress has been made in understanding its molecular mechanisms through the usage of genetic, teratogenic, and surgical models. The following review focuses on the teratogenic and surgical models of CDH and the possible molecular mechanisms of nitrofen (a diphenyl ether, formerly used as an herbicide) in both induction of CDH and pulmonary hypoplasia. In addition, the mechanisms of other compounds including several anti-inflammatory agents that have been linked to CDH will be discussed. Furthermore, this review will also explore the importance of vitamin A in lung and diaphragm development and the possible mechanisms of teratogen interference in vitamin A homeostasis. Continued exploration of these models will bring forth a clearer understanding of CDH and its molecular underpinnings, which will ultimately facilitate development of therapeutic strategies.

Topics: Animals; Diaphragm; Disease Models, Animal; Dogs; Hernia, Diaphragmatic; Lung; Models, Animal; Phenyl Ethers; Rabbits; Rats; Sheep; Signal Transduction; Species Specificity; Teratogens; Tretinoin; Vitamin A; Vitamin A Deficiency

Monocrotaline (MCT), a pyrrolizidine alkaloid extracted from the shrub Crotalaria spectabilis, induces in the lungs of many mammalian species severe hypertension and fibrosis. Previous work with MCT-induced lung disease in rats has shown that some of the steps to progressive fibrosis can be interrupted or decreased by intervention with retinoic acid (RA) or with the angiotensin converting enzyme inhibitor, captopril. This report emphasizes the pathology and cytokines present in lungs of rats in the MCT model of hypertension and fibrosis in 8 treatment groups, six per group: (1) controls, not treated; (2) captopril; (3) RA; (4) combined captopril and RA. Groups 5-8 replicated groups 1-4 and also received MCT subcutaneously. Tissues were harvested at 28 days for histopathology and measurement of cytokines TGFbeta, TNFalpha, interleukin 6, and IFN_. TGFbeta was depressed at 28 days by MCT, an effect reversed by a combination of captopril and RA. RA influences production of an important Th1 cytokine, IFN_, and demonstrated the greatest limitation of MCT-induced TNFalpha. The MCT-induced lung pathology of vasculitis, interstitial pneumonia and fibrosis was limited by captopril. Smooth muscle actin was overexpressed in MCT treated animals receiving RA, an effect reduced with captopril. Overall, the study confirmed the existence of a protective effect for both captopril and RA from MCT-induced lung damage at 30 days. No synergistic or antagonistic activity was observed when the two drugs were administered together. Each of the drugs exerts different and particular effects on serum and tissue levels of various cytokines, suggesting that each drug is efficient at different points of attack in the control of lung fibrosis.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Antioxidants; Captopril; Cytokines; Disease Models, Animal; Male; Monocrotaline; Pulmonary Fibrosis; Rats; Rats, Sprague-Dawley; Tretinoin

Hyperpnoeic episodic breathing (HEB), a cyclic waxing and waning of breathing, has been widely reported in pre-term neonates, patients with Joubert syndrome and adults (Cheyne-Stokes respiration) with congestive heart failure and brainstem infarction. We now provide a developmental mouse model of neonatal HEB. We used retinoic acid (RA) (0.5-10 mg/kg of maternal weight) to alter embryonic development of the respiratory neuronal network at the onset of hindbrain segmentation (7.5 days post-coitum). HEB was observed in vivo after RA treatment during post-natal days 1-7 but not in control animals. HEB persisted after reduction of the chemoafferent input by hypocapnic hyperoxia (100% O(2)). A large increase and decrease of the rhythm resembling an HEB episode was induced in vitro by stimulating the parafacial respiratory oscillator in treated but not in control neonates. Post-natal localization of the superior cerebellar peduncle and adjacent dorsal tegmentum was found to be abnormal in the pons of RA-treated juvenile mice. Thus, early developmental specifications in the rostral hindbrain are required for the development of neurones that stabilize the function of the respiratory rhythm generator, thereby preventing HEB during post-natal maturation.

Topics: Animals; Animals, Newborn; Body Patterning; Cheyne-Stokes Respiration; Disease Models, Animal; Dose-Response Relationship, Drug; Embryo, Mammalian; Female; Gene Expression Regulation, Developmental; Genes, Developmental; In Situ Hybridization; In Vitro Techniques; Mice; Microscopy, Electron, Transmission; Plethysmography; Pregnancy; Prenatal Exposure Delayed Effects; Rhombencephalon; Tretinoin

Isoflavonoids isolated from plants have been confirmed to fight osteoporosis and promote bone health. However, few studies have been conducted to describe the anti-osteoporosis activity of botanical flavonone. Based on the experimental outcomes, we demonstrated the ability of naringin to fight osteoporosis in vitro. We developed a retinoic acid-induced osteoporosis model of rats to assess whether naringin has similar bioactivity against osteoporosis in vitro. After a 14-day supplement of retinoic acid to induce osteoporosis, SD rats were administered naringin. A blood test showed that naringin-treated rats experienced significantly lower activity of serum alkaline phosphatase and had higher femur bone mineral density, compared to untreated rats. All three dosages of naringin improved the decrease in bone weight coefficient, the length and the diameter of the bone, the content of bone ash, calcium, and phosphorus content induced by retinoic acid. The data of histomorphological metrology of naringin groups showed no difference as compared to normal control rats. These outcomes suggest that naringin offer a potential in the management of osteoporosis in vitro.

Topics: Alkaline Phosphatase; Animals; Bone Density; Calcium; Disease Models, Animal; Female; Femur; Flavanones; Minerals; Osteogenesis; Osteoporosis; Phosphorus; Phytotherapy; Random Allocation; Rats; Rats, Sprague-Dawley; Tretinoin

Adult Naval Medical Research Institute (NMRI) mice, after prenatal exposure to retinoic acid (RA), were treated with a standard two-stage skin carcinogenesis regime to characterize hyperplastic epidermal foci that precede the appearance of cutaneous papillomas, and to investigate the in vivo long-term action of RA on adult mouse skin treated with DMBA (7,12 dimethyl benz[a]anthracene) and TPA (12-O-tetradecanoylphorbol 13-acetate). The results demonstrate that RA administered to pregnant mice had a long-term inhibitory action on the cell differentiation and development of hyperplastic lesions occurring prior to cancer on the adult skin of their offspring as well as a stimulatory effect on cell proliferation of these hyperplastic lesions.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Administration, Oral; Animals; Carcinogens; Cell Differentiation; Disease Models, Animal; Female; Keratolytic Agents; Mice; Papilloma; Pregnancy; Prenatal Exposure Delayed Effects; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tretinoin

All-trans retinoic acid (ATRA) stimulates platelet-derived growth factor (PDGF)-A expression and enhances alveolarization in rat lungs. On d 16 of gestation, pregnant Sprague-Dawley rats were randomly assigned to either a retinoic acid group (intragastric ATRA at 10 mg/kg body weight) or a vehicle group. We punctured each amniotic sac, and fetuses in the opposite uterine horn served as controls. On d 21 of gestation, the fetuses were delivered by cesarean section. Rats subjected to oligohydramnios exhibited significantly lower lung weights and lung/body weight ratios, and ATRA had no effects on the body or lung weights of oligohydramnios-exposed rats. Lung PDGF-A and -B mRNA expression was significantly lower in oligohydramnios-exposed rats compared with control littermates of maternal vehicle-treated dams. Maternal retinoic acid treatment significantly increased PDGF-A and -B mRNA expression in control and oligohydramnios-exposed rats compared with all rats and oligohydramnios-exposed rats of maternal vehicle-treated dams, respectively. Rats exposed to oligohydramnios exhibited a significantly lower generation of alveolar saccules than did control rats in the maternal retinoic acid- and vehicle-treated groups. In this model, maternal retinoic acid treatment showed no positive effects on oligohydramnios-induced pulmonary hypoplasia in the pseudoglandular stage.

Topics: Amnion; Animals; Body Weight; Disease Models, Animal; Female; Fetal Organ Maturity; Gestational Age; Immunohistochemistry; Lung; Lung Diseases; Oligohydramnios; Organ Size; Platelet-Derived Growth Factor; Pregnancy; Proto-Oncogene Proteins c-sis; Pulmonary Alveoli; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tretinoin; Up-Regulation

Vascular endothelial growth factor (VEGF) has an important role in the pathogenesis of retinopathy of prematurity (ROP) and inhibition of VEGF expression in the neovascular phase might prevent destructive neovascularization in ROP. It is suggested that retinoids exert a highly potent antiangiogenic activity by inhibiting VEGF expression. The aim of this study was to demonstrate the preventive effect of retinoic acid (RA) on the VEGF-induced retinal neovascularization in a rat model of ROP. Wistar albino rats were placed into incubators at birth and exposed to an atmosphere alternating between 50 % and 10 % O(2) every 24 hours. After 14 days, the animals were removed to room air and received either an intraperitoneal injection of RA (5 mg/kg/day) (n=9) or saline (n=4) daily for six days, and sacrificed at 21 days. Other rats (n=4) were raised in room air and served as age-matched controls. The globe of each eye was cut through the cornea and embedded in paraffin. Serial sections were stained with hematoxylin-eosin for quantification of neovascular nuclei. The avidin-biotin peroxidase method was performed for evaluation of VEGF expression. The average number of neovascular nuclei was significantly lower in the control group compared to that in the ROP groups. In addition, it significantly decreased in the RA-treated ROP group compared to that of the saline-administrated ROP group. VEGF immunostaining was overall negative in room air-exposed rats. The VEGF immunostaining score significantly decreased in the RA-treated ROP group compared to that in the saline-administered ROP group. RA treatment might be beneficial in preventing neovascularization resulting from oxygen-induced retinopathy by downregulation of VEGF expression.

Topics: Animals; Animals, Newborn; Disease Models, Animal; Humans; Infant, Newborn; Rats; Rats, Wistar; Retina; Retinal Neovascularization; Retinopathy of Prematurity; Tretinoin; Vascular Endothelial Growth Factor A

There is increasing evidence to suggest that the retinoid pathway is involved in the pathogenesis of congenital diaphragmatic hernia (CDH). We hypothesised that retinoids are involved in the pathogenesis of associated pulmonary hypoplasia in CDH and therefore designed this study to investigate the effects of retinoid acid on nitrofen-induced hypoplastic lungs. Pregnant rats were exposed to either olive oil or 100 mg nitrofen on day 9.5 of gestation. Foetal lungs were harvested on embryonic day 13.5 and were cultured for 96 h with or without exogenous retinoic acid (RA) (1 muM) added daily to the culture medium. Lungs were divided into four study groups: control (n=31); control + RA (n=19); nitrofen (n=19); and nitrofen + RA (n=12). Lung growth was assessed in each group by measuring branching morphogenesis, total DNA content and the proportion of proliferating cells stained by immunohistochemistry. One-way ANOVA test was used for statistical analysis. Retinoic acid significantly increased the growth of nitrofen-induced hypoplastic lungs, whilst growth of control lungs did not change. The number of lung buds and lung area of nitrofen-exposed hypoplastic lungs after 96 h of culture significantly increased after the addition of RA compared to the non-treated hypoplastic lungs (25.75+/-6.47 vs 15.11+/-3.29 and 0.98+/-0.18 mm(2) vs 0.65+/-0.13 mm(2), respectively; P<0.0001). Lung perimeter was also higher when RA was added to hypoplastic lungs compared to the non-treated ones, although it did not reach significance (12.51+/-2.53 mm vs 11.19+/-2.56 mm; P=0.17). Conversely, the addition of RA to control lungs did not affect the number of lung buds, lung area or lung perimeter after 96 h in culture compared to the non-treated ones (31.28+/-4.66 vs 31.81+/-6.67; 1.29+/-0.18(2) vs 1.29+/-0.23 mm(2) and 18.47+/-3.47 mm vs 17.89+/-2.94 mm, respectively; P=NS). Retinoic acid also increased the total DNA content and the proportion of proliferating cells in hypoplastic lungs compared to the non-treated ones (2.59+/-0.58 mug vs 1.96+/-0.31 mug and 57.89+/-9.46% vs 36.76+/-8.15%, respectively; P<0.001). The addition of RA did not affect either total DNA content or the proportion of proliferating cells in control lungs compared to the non-treated ones (4.04+/-0.64 mug vs 3.79+/-0.85 mug and 58.67+/-11.23% vs 56.03+/-10.36%, respectively; P=NS). This study demonstrates for the first time that RA rescues lung hypoplasia in nitrofen-induced hypoplastic lungs. These results su

Topics: Analysis of Variance; Animals; Disease Models, Animal; Female; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Lung; Pregnancy; Random Allocation; Rats; Rats, Sprague-Dawley; Retinoids; Signal Transduction; Tretinoin

22q11 deletion (del22q11) syndrome is characterized genetically by heterozygous deletions within chromosome 22q11 and clinically by a constellation of congenital malformations of the aortic arch, heart, thymus, and parathyroid glands described as DiGeorge syndrome (DGS). Here, we report that compound heterozygosity of mouse homologs of two 22q11 genes, CRKL and TBX1, results in a striking increase in the penetrance and expressivity of a DGS-like phenotype compared to heterozygosity at either locus. Furthermore, we show that these two genes have critical dose-dependent functions in pharyngeal segmentation, patterning of the pharyngeal apparatus along the anteroposterior axis, and local regulation of retinoic acid (RA) metabolism and signaling. We can partially rescue one salient feature of DGS in Crkl+/-;Tbx1+/- embryos by genetically reducing the amount of RA produced in the embryo. Thus, we suggest that del22q11 is a contiguous gene syndrome involving dose-sensitive interaction of CRKL and TBX1 and locally aberrant RA signaling.

Topics: Adaptor Proteins, Signal Transducing; Animals; Aorta; Branchial Region; Chromosomes, Human, Pair 22; Cytochrome P-450 Enzyme System; DiGeorge Syndrome; Disease Models, Animal; Embryo, Mammalian; Gene Deletion; Gene Expression; Gene Expression Regulation, Developmental; Genotype; Homeodomain Proteins; Humans; In Situ Hybridization; Mice; Mice, Inbred C57BL; Mice, Knockout; Nuclear Proteins; Retinoic Acid 4-Hydroxylase; Signal Transduction; T-Box Domain Proteins; Thymus Gland; Tretinoin

9-cis-Retinoic acid (9cRA) binds both retinoic acid receptors (RARs) and retinoid X receptors (RXRs) and has been shown to be a potential chemopreventive agent both in lung cancer cell culture studies and in clinical trials studying former smokers. However, direct evidence of the efficacy of 9cRA against lung tumor development in vivo is lacking. In the present study, we determined whether treatment with 9cRA has the potential to inhibit lung carcinogenesis by upregulating RAR-beta and down-regulating COX-2 expression in the A/J mouse lung cancer model. A/J mice (n=14-15/group) were treated as follows: (1) Control (Sham treated); (2) NNK (100mg NNK/kg body weight); (3) NNK+9cRA (15mg/kg diet); and (4) NNK+celecoxib (a COX-2-specific inhibitor, 500mg/kg diet). Tumor incidence, tumor multiplicity, RAR-beta mRNA, COX-2 mRNA, and COX-2 protein levels in lung samples of mice were determined 4 months after carcinogen injection. The results showed that mice receiving 9cRA supplementation had significantly lower tumor multiplicity (48% reduction, P<0.05) and showed a trend toward lower tumor incidence (40% reduction, P=0.078), as compared with the mice given NNK alone. Although, celecoxib treatment resulted in greater declines in tumor incidence and tumor multiplicity (75 and 88%, respectively, P<0.05), the chemoprotective effects of celecoxib were accompanied by increased mortality while 9cRA treatment resulted in no weight-loss associated toxicity or mortality. Supplementation with 9cRA was effective in increasing RAR-beta mRNA, but this increase was not accompanied by decreased levels of COX-2 mRNA or protein. These results suggest that 9cRA supplementation may provide protection against lung carcinogenesis and this effect may be mediated in part by 9cRA induction of RAR-beta, but not inhibition of COX-2 transcription.

Topics: Alitretinoin; Animals; Antineoplastic Agents; Carcinogens; Celecoxib; Cell Transformation, Neoplastic; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dietary Supplements; Disease Models, Animal; Lung; Lung Neoplasms; Male; Membrane Proteins; Mice; Mice, Inbred A; Nitrosamines; Pyrazoles; Receptors, Retinoic Acid; Sulfonamides; Tretinoin

Fenretinide [N-(4-hydroxyphenyl)retinamide or 4-HPR] is a synthetic retinoid analogue with antitumor and chemopreventive activities. N-(4-Methoxyphenyl)retinamide (4-MPR) is the most abundant metabolite of 4-HPR detected in human serum following 4-HPR therapy. We have shown in in vitro studies that 4-HPR and 4-MPR can act independent of the classic nuclear retinoid receptor pathway and that 4-HPR, but not 4-MPR, can also activate nuclear retinoid receptors. In this study, we have compared the chemopreventive effects of topically applied 4-HPR and 4-MPR with the primary biologically active retinoid, all-trans retinoic acid (ATRA), in vivo in the mouse skin two-stage chemical carcinogenesis model. All three retinoids suppressed tumor formation but the effect of 4-HPR and 4-MPR, and not of ATRA, was sustained after their discontinuation. The tumor-suppressive effects of 4-HPR and 4-MPR were quantitatively and qualitatively similar, suggesting that the two may be acting through the same retinoid receptor-independent mechanism(s). We further explored this effect in vitro by analyzing primary cultures of mouse keratinocytes treated with the same retinoids. All three could induce apoptosis with a 48-hour treatment and only ATRA and 4-HPR induced an accumulation of cells in the G1 phase of the cell cycle. This finding is consistent with our previous results showing that the effects of phenylretinamides on the cell cycle are retinoid receptor dependent whereas apoptosis induction is not. A microarray-based comparison of gene expression profiles for mouse skin treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) alone and TPA + 4-HPR or TPA + 4-MPR reveals a high degree of coincidence between the genes regulated by the two phenylretinamides. We propose that 4-HPR may exert therapeutic and chemopreventive effects by acting primarily through a retinoid receptor-independent mechanism(s) and that 4-MPR may contribute to the therapeutic effect of 4-HPR by acting through the same retinoid receptor-independent mechanism(s).

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Chemoprevention; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Fenretinide; G1 Phase; Gene Expression Profiling; In Vitro Techniques; Keratinocytes; Mice; Mice, Inbred SENCAR; Oligonucleotide Array Sequence Analysis; Retinoid X Receptors; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tretinoin; Tumor Suppressor Proteins

To evaluate the antiproliferative effect of an all-trans retinoic acid (at-RA) drug delivery system (DDS) on experimental proliferative vitreoretinopathy (PVR).. PVR was induced in rabbits with core vitrectomy and fibroblast injection. The DDS containing 420 microg, 650 microg, and 1,070 microg of at-RA was implanted into the vitreous of treated groups B, C, and D, respectively. Group A with no DDS and group E with nonmedicated DDS served as controls. The intravitreal at-RA concentration was measured with high-pressure liquid chromatography. The drug toxicity was evaluated histologically.. The severity of PVR was significantly reduced in groups C and D but not in groups A, B, and E. The drug release peaked at 6 weeks to 7 weeks. No signs of retinal toxicity were found in the DDS groups.. Intravitreal implantation of at-RA DDS appears effective in inhibiting the development of PVR and is well tolerated in rabbit eyes.

Topics: Absorbable Implants; Animals; Chromatography, High Pressure Liquid; Disease Models, Animal; Drug Delivery Systems; Drug Implants; Fibroblasts; Lactic Acid; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Polymers; Rabbits; Tretinoin; Vitrectomy; Vitreoretinopathy, Proliferative; Vitreous Body

Viral hepatitis infection, which is a major cause of liver fibrosis, is associated with activation of innate immunity. However, the role of innate immunity in liver fibrosis remains obscure.. Liver fibrosis was induced either by feeding mice with the 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet or by injecting them with carbon tetrachloride. The Toll-like receptor 3 ligand, polyinosinic-polycytidylic acid, was used to activate innate immunity cells and mediators, including natural killer cells and interferon gamma.. In the mouse model of DDC-induced liver fibrosis, natural killer cell activation by polyinosinic-polycytidylic acid induced cell death to activated hepatic stellate cells and attenuated the severity of liver fibrosis. Polyinosinic-polycytidylic acid treatment also ameliorated liver fibrosis induced by carbon tetrachloride. The observed protective effect of polyinosinic-polycytidylic acid on liver fibrosis was diminished through either depletion of natural killer cells or by disruption of the interferon gamma gene. Expression of retinoic acid early inducible 1, the NKG2D ligand, was undetectable on quiescent hepatic stellate cells, whereas high levels were found on activated hepatic stellate cells, which correlated with the resistance and susceptibility of quiescent hepatic stellate cells and activated hepatic stellate cells to natural killer cell lysis, respectively. Moreover, treatment with polyinosinic-polycytidylic acid or interferon gamma enhanced the cytotoxicity of natural killer cells against activated hepatic stellate cells and increased the expression of NKG2D and tumor necrosis factor-related apoptosis-inducing ligand on liver natural killer cells. Blocking NKG2D or tumor necrosis factor-related apoptosis-inducing ligand with neutralizing antibodies markedly diminished the cytotoxicity of polyinosinic-polycytidylic acid-activated natural killer cells against activated hepatic stellate cells.. Our findings suggest that natural killer cells kill activated hepatic stellate cells via retinoic acid early inducible 1/NKG2D-dependent and tumor necrosis factor-related apoptosis-inducing ligand-dependent mechanisms, thereby ameliorating liver fibrosis.

Topics: Animals; Apoptosis; Disease Models, Animal; DNA Primers; Flow Cytometry; Hepatitis, Viral, Animal; Killer Cells, Natural; Ligands; Liver Cirrhosis, Experimental; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; NK Cell Lectin-Like Receptor Subfamily K; Perforin; Pore Forming Cytotoxic Proteins; Receptors, Immunologic; Receptors, Natural Killer Cell; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin

The purpose of this study was to examine the possibility that all-trans-retinoic acid (RA) in the eye is a signal related to changes in scleral extracellular matrix in a primate model of postnatal eye growth.. Juvenile marmosets (Callithrix jacchus) were divided into two experimental groups based on their response to monocular deprivation with diffusers: group 1, treated eyes becoming longer than fellow control eyes (n = 8), and group 2, treated eyes becoming shorter than control eyes (n = 7). Eyes were enucleated, dissected, and assayed for changes in the rates of scleral glycosaminoglycan (GAG) synthesis and ocular RA synthesis. The rate of incorporation of (35)SO4 into CPC-precipitable GAG in scleras was taken as a measure of the rate of synthesis of proteoglycans. In the same eyes the rate of RA synthesis in vivo was measured separately in the retina and the choroid/RPE (choroid with RPE attached) by HPLC. The effect of RA on the rate of scleral GAG synthesis was also examined in tissue-cultured pieces of sclera from additional marmosets.. Induced changes in vitreous chamber length in diffuser-treated eyes correlated inversely with the rate of scleral GAG synthesis (P < 0.05) and directly correlated with the rate of RA synthesis measured separately in the retina (P < 0.05) and the choroid/RPE (P < 0.05). In group 1, the rate of scleral GAG synthesis was significantly lower (P < 0.01) in the treated eyes relative to control eyes, and the rate of RA synthesis in both the retina and the choroid/RPE was significantly higher (P < 0.01). In group 2, the rates of scleral GAG synthesis and RA synthesis in either the retina or choroid/RPE were not found to change significantly in the treated eyes compared with the control eyes. RA partially reduces the rate of scleral GAG synthesis in tissue-cultured primate sclera in a dose-dependent manner after several days.. RA may play a role in the visual control of postnatal eye growth in primates, possibly by inducing changes in scleral extracellular matrix associated with increasing eye size. Decreasing growth rate below control levels may involve other mechanisms.

Topics: Animals; Callithrix; Choroid; Chromatography, High Pressure Liquid; Disease Models, Animal; DNA; Extracellular Matrix; Eye; Glycosaminoglycans; Myopia; Organ Culture Techniques; Retina; Sclera; Sensory Deprivation; Tretinoin; Vitreous Body

To investigate the effect of gallium salts on bone metabolism in osteoporosis rats caused by tretinoin.. After duplicating osteoporotic model of rats by using tretinoin, we observed the metabolism of blood, urine and bone in vivo. The rats were divided into control group, osteoporosis group, estrogen treated and gallium chloride treated group. The indexes of bone metabolism and related indexes in serum and urine were observed after 60 days of treatment. In the same time, we observed the dynamic effect of 30 days and 60 days of treatment.. After duplicating osteoporotic model, rats' bone structures were injured, the bone mineral density and the organic matrix decreased, the contents of tartrate-resistant acid phosphatase (TRAP) in serum were higher. After gallium salt treating, the above damages were inhibited or retarded. Trabecular width and thickness of bone cortex were significantly increased. AKP and TRAP activities were decreased to the level close to that of the control group.. Gallium salt is effective in treating osteoporosis.

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Bone Density; Disease Models, Animal; Female; Gallium; Isoenzymes; Osteoporosis; Random Allocation; Rats; Rats, Sprague-Dawley; Tartrate-Resistant Acid Phosphatase; Tretinoin

Cell culture experiments indicated that activation of the retinoic acid signaling system is involved in axonal regeneration. This hypothesis was tested with sciatic nerve injury in the rat. Since the effect of retinoic acid is mediated via retinoic acid receptors and retinoid X receptors, we investigated mRNA and protein expression of these receptors during injury-induced degeneration and regeneration. Seven days after crush injury, transcript concentrations of all retinoic acid receptors and of retinoid X receptor alpha were significantly higher than in non-lesioned nerves. Protein levels of retinoic acid receptor alpha, retinoic acid receptor beta and retinoid X receptor alpha were upregulated 4, 7 and 14 days after injury. In degenerating nerves a significant increase of retinoic acid receptor alpha was detected 7 and 14 days, and of retinoic acid receptor beta 14 and 21 days after complete transection. Immunohistochemical staining of retinoid receptors revealed their expression in Schwann cells and macrophages. In addition, we observed that retinoic acid receptor alpha and retinoid X receptor alpha appeared in the cell nuclei of macrophages during the lesion-induced inflammatory reaction, and that retinoid X receptor alpha-staining co-localized with some regenerating axons. Experiments with Schwann cell primary cultures revealed an effect of retinoic acid on the expression of the neuregulin receptor ErbB3, suggesting that one function of retinoic acid consists in the regulation of neuroglial interactions after peripheral nerve injury.

Topics: Animals; Animals, Newborn; Blotting, Northern; Blotting, Western; Cells, Cultured; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Immunohistochemistry; Macrophages; Male; Rats; Rats, Sprague-Dawley; Receptor, Nerve Growth Factor; Receptors, Retinoic Acid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Schwann Cells; Sciatic Neuropathy; Time Factors; Tretinoin

The retinoid-related molecules (RRMs) ST1926 [(E)-3-(4'-hydroxy-3'-adamantylbiphenyl-4-yl)acrylic acid] and CD437 (6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid) are promising anticancer agents. We compared the retinoic acid receptor (RAR) trans-activating properties of the two RRMs and all-trans-retinoic acid (ATRA). ST1926 and CD437 are better RARgamma agonists than ATRA. We used three teratocarcinoma cell lines to evaluate the significance of RARgamma in the activity of RRMs: F9-wild type (WT); F9gamma-/-, lacking the RARgamma gene; F9gamma51, aF9gamma-/-derivative, complemented for the RARgamma deficit. Similar to ATRA, ST1926 and CD437 activate cytodifferentiation only in F9-WT cells. Unlike ATRA, ST1926 and CD437 arrest cells in the G2/M phase of the cell cycle and induce apoptosis in all F9 cell lines. Our data indicate that RARgamma and the classic retinoid pathway are not relevant for the antiproliferative and apoptotic activities of RRMs in vitro. Increases in cytosolic calcium are fundamental for apoptosis, in that intracellular calcium chelators abrogate the process. Comparison of the gene expression profiles associated with ST1926 and ATRA in F9-WT and F9gamma-/-indicates that the RRM activates a conspicuous nonretinoid response in addition to the classic and RAR-dependent pathway. The pattern of genes regulated by ST1926 selectively, in a RARgamma-independent manner, provides novel insights into the possible molecular determinants underlying the activity of RRMs in vitro. Furthermore, it suggests that RARgamma-dependent responses are relevant to the activity of RRMs in vivo. Indeed, the receptor hinders the antitumor activity in vivo, in that both syngeneic and immunosuppressed SCID mice bearing F9gamma-/- tumors have increased life spans after treatment with ST1926 and CD437 relative to their F9-WT counterparts.

Topics: Adamantane; Animals; Antineoplastic Agents; Calcium; Cell Death; Cell Differentiation; Cells, Cultured; Chlorocebus aethiops; Cinnamates; COS Cells; Cytosol; Disease Models, Animal; G2 Phase; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, SCID; Mitosis; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; Retinoids; RNA, Messenger; Teratocarcinoma; Tretinoin

Pulmonary inflammation, increased production of the inflammatory cytokine interleukin-1beta (IL-1beta), and vitamin A deficiency are risk factors for the development of bronchopulmonary dysplasia (BPD) in premature infants. To determine the mechanisms by which IL-1beta influences lung development, we have generated transgenic mice in which human IL-1beta is expressed in the lung epithelium with a doxycycline-inducible system controlled by the Clara cell secretory protein promoter. Perinatal IL-1beta production in these mice causes a phenotype that is strikingly similar to BPD. Pulmonary pathology in the mice shows inflammation, lack of alveolar septation, and impaired vascular development of the lung, similar to the histological characteristics of BPD. Retinoic acid (RA), one of the most biologically active derivatives of vitamin A, increases septation. Proteins involved in mediating the cellular responses to RA include the cellular retinoic acid binding proteins CRABP-I and CRABP-II and the nuclear retinoic acid receptors RAR-alpha, RAR-beta, and RAR-gamma.. To test the hypothesis that IL-1beta inhibits the expression of proteins involved in mediating the cellular response to RA.. The mRNA expression of CRABP-I, CRABP-II, RAR-alpha1, RAR-beta2, RAR-beta4, and RAR-gamma2 was studied with real-time RT-PCR on gestational day 18, and postnatal days 0, 1, 5, and 7 in IL-1beta-expressing mice and their control littermates. In addition, immunohistochemistry for CRABP-I was performed.. IL-1beta decreased the mRNA expression and protein production of CRABP-I as well as the mRNA expression of RAR-gamma2. In contrast, no differences between IL-1beta-expressing and control mice were detected in the expression of CRABP-II, RAR-alpha1, RAR-beta2, or RAR-beta4.. The present study demonstrates for the first time a link between inflammation and the retinoic acid pathway. Inhibition of CRABP-I and RAR-gamma2 expression may be one mechanism by which inflammation prevents alveolar septation. The therapeutic potential of RA in promoting septation in the setting of perinatal lung inflammation deserves further investigation.

Topics: Animals; Bronchopulmonary Dysplasia; Disease Models, Animal; Gene Expression Profiling; Gene Expression Regulation; Humans; Infant, Newborn; Infant, Premature; Interleukin-1; Mice; Mice, Transgenic; Pulmonary Alveoli; Respiratory Mucosa; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin

GFP labeled/NE-4C neural progenitor cells cloned from primary neuroectodermal cultures of p53- mouse embryos give rise to neurons when exposed to retinoic acid in vitro. To study their survival and differentiation in vivo, cells were transplanted into the cortex of 6-week-old rats, 1 week after the induction of a photochemical lesion or into noninjured cortex. The electrophysiological properties of GFP/NE-4C cells were studied in vitro (8-10 days after differentiation induction) and 4 weeks after transplantation using the whole-cell patch-clamp technique, and immunohistochemical analyses were carried out. After transplantation into a photochemical lesion, a large number of cells survived, some of which expressed the astrocytic marker GFAP. GFP/GFAP-positive cells, with an average resting membrane potential (Vrest) of -71.9 mV, displayed passive time- and voltage-independent K+ currents and, additionally, voltage-dependent A-type K+ currents (KA) and/or delayed outwardly rectifying K+ currents (KDR). Numerous GFP-positive cells expressed NeuN, betaIII-tubulin, or 68 kD neurofilaments. GFP/betaIII-tubulin-positive cells, with an average Vrest of -61.6 mV, were characterized by the expression of KA and KDR currents and tetrodotoxin-sensitive Na+ currents. GFP/NE-4C cells also gave rise to oligodendrocytes, based on the detection of oligodendrocyte-specific markers. Our results indicate that GFP/NE-4C neural progenitors transplanted into the site of a photochemical lesion give rise to neurons and astrocytes with membrane properties comparable to those transplanted into noninjured cortex. Therefore, GFP/NE-4C cells provide a suitable model for studying neuro- and gliogenesis in vivo. Further, our results suggest that embryonic neuroectodermal progenitor cells may hold considerable promise for the repair of ischemic brain lesions.

Topics: Animals; Antineoplastic Agents; Astrocytes; Brain Ischemia; Cell Differentiation; Cell Line; Cerebral Cortex; Denervation; Disease Models, Animal; Ectoderm; Graft Survival; Green Fluorescent Proteins; Immunohistochemistry; Membrane Potentials; Mice; Neurons; Oligodendroglia; Patch-Clamp Techniques; Photosensitizing Agents; Stem Cell Transplantation; Stem Cells; Tretinoin

Elastase-induced changes in lung morphology and function were detected in spontaneously breathing rats using conventional proton MRI at 4.7 T. A single dose of porcine pancreatic elastase (75 U/100 g body weight) or vehicle (saline) was administered intratracheally (i.t.) to male Brown Norway (BN) rats. MRI fluid signals were detected in the lungs 24 hr after administration of elastase and resolved within 2 weeks. These results correlated with perivascular edema and cellular infiltration observed histologically. Reductions in MRI signal intensity of the lung parenchyma, and increases in lung volume were detected as early as 2 weeks following elastase administration and remained uniform throughout the study, which lasted 8 weeks. Observations were consistent with air trapping resulting from emphysema detected histologically. In a separate experiment, animals were treated daily intraperitoneally (i.p.) with all-trans-retinoic acid (ATRA; 500 microg/kg body weight) or its vehicle (triglyceride oil) starting on day 21 after elastase administration and continuing for 12 days. Under these conditions, ATRA did not elicit a reversal of elastase-induced lung damage as measured by MRI and histology. The present approach complements other validated applications of proton MRI in experimental lung research as a method for assessing drugs in rat models of respiratory diseases.

Topics: Animals; Disease Models, Animal; Emphysema; Image Interpretation, Computer-Assisted; Lung; Magnetic Resonance Imaging; Male; Pancreatic Elastase; Prognosis; Protons; Rats; Respiratory Mechanics; Treatment Outcome; Tretinoin

13-cis-retinoic acid (13-cis-RA, isotretinoin) is used to treat severe recalcitrant acne. Other retinoids have adverse effects on bone. Recent studies of human patients treated with 13-cis-RA have had varying results, perhaps because of variability among patients and the lack of control groups. The effects of retinoids have been studied in rodents, but little information is available regarding the effects of clinically relevant retinoid doses as evaluated by use of bone densitometric techniques. We treated rats for 15 or 20 wk with 13-cis-RA, all-trans-RA, or soybean oil (control) by gavage. We used dual-energy X-ray absorptiometry, histomorphometry, and histologic evaluation to evaluate effects on bone. Spontaneous long bone fractures occurred in some rats treated with 15 mg/kg all-trans-RA daily. Bone mineral density, bone mineral content, bone diameter, and cortical thickness of the femur were reduced in rats treated daily with 10 or 15 mg/kg all-trans-RA or 30 mg/kg 13-cis-RA. The lumbar spine was not affected. Although the effects of 13-cis-RA were not as dramatic as those of all-trans-RA, further study of the effects of 13-cis-RA on long bones is warranted.

Topics: Absorptiometry, Photon; Administration, Oral; Animals; Bone Density; Bone Resorption; Dermatologic Agents; Disease Models, Animal; Female; Humans; Isotretinoin; Male; Osteoporosis; Rats; Rats, Sprague-Dawley; Species Specificity; Tretinoin

Oxygen-induced lung injury is believed to lead to the development of bronchopulmonary dysplasia (BPD). To determine whether retinoic acid (RA) treatment prevents the development of BPD by minimizing lung injury, we investigated the effect of RA on the histopathologic characteristics of oxygen-induced lung injury in a newborn rat model. Eighteen rat pups were divided into three groups: room air-exposed control group (n=5), oxygen-exposed placebo group (n=7), and RA-treated oxygen-exposed group (n=6). Measurement of alveolar area, quantitation of secondary crest formation, microvessel count, evaluation of alveolar septal fibrosis, and smooth muscle actin (SMA) immunostaining were performed to assess oxygen-induced changes in lung morphology. Treatment of oxygen-exposed animals with RA resulted in a significant increase in mean alveolar area; however, it had no effect on the number of secondary crests and microvessel count. The degree of fibrosis and SMA expression showed a significant decrease in RA-treated animals. We conclude that RA treatment improves alveolar structure and decreases fibrosis in the newborn rat with oxygen-induced lung injury. Extrapolating these findings to humans, we speculate that similar treatment with RA may reduce lung injury in preterm infants at risk for BPD.

Topics: Animals; Animals, Newborn; Antioxidants; Bronchopulmonary Dysplasia; Disease Models, Animal; Humans; Infant, Newborn; Oxygen Inhalation Therapy; Pulmonary Alveoli; Rats; Rats, Wistar; Risk Factors; Tretinoin

all-trans retinoic acid (atRA), the oxidative metabolite of vitamin A, is essential for normal embryonic development. Also, high levels of atRA are teratogenic in many species and can effectively induce cleft palate in the mouse. Most cleft palate resulted from the failed fusion of secondary palate shelves, and maintenance of the normal cell proliferation is important in this process of shelf growth. To clarify the mechanism by which atRA causes cleft palate, we investigated the effect of atRA on proliferation activity and cell cycle distribution in mouse embryonic palatal mesenchymal (MEPM) cells. atRA inhibited the growth of MEPM cells by inducing apoptosis in a dose-dependent manner. atRA also caused a G1 block in the cell cycle with an increase in the proportion of cells in G0/G1 and a decrease in the proportion of cells in S phase, as determined by flow cytometry. We next investigated the effects of atRA on molecules that regulate the G1 to S phase transition. These studies demonstrated that atRA inhibited expression of cyclins D and E at the protein level. Furthermore, atRA treatment reduced phosphorylated Rb and decreased cdk2 and cdk4 kinase activity. These data suggest that atRA had antiproliferative activity by modulating G1/S cell cycle regulators and by inhibition of Rb phosphorylation in MEPM cells, which might account for the pathogenesis of cleft palate induced by retinoic acid.

Topics: Animals; Apoptosis; CDC2-CDC28 Kinases; Cell Cycle; Cell Survival; Cells, Cultured; Cyclin D; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; Cyclins; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Flow Cytometry; Male; Mesoderm; Mice; Mice, Inbred ICR; Palate; Phosphorylation; Proto-Oncogene Proteins; Retinoblastoma Protein; Teratogens; Tretinoin

Systemic retinoic acid (RA) treatment for chemoprevention of squamous cell carcinoma of the head and neck (HNSCC) is limited by RA's toxic side effects at therapeutic doses. The pulsed-dye laser (PDL), through a mechanism of selective vascular targeting, may allow reduction of the RA dose to one that is better tolerated when these treatments are used in combination. This study tests our hypothesis that combination therapy of PDL irradiation and low-dose systemic RA is as effective as high-dose RA therapy alone in the chemoprevention of HNSCC.. Randomized, prospective study in a hamster model.. Dysplastic lesions were induced in the cheek pouches of 48 hamsters by painting with topical 9,10-dimethl-1,2-benzanthrancene (DMBA). The hamsters were randomly divided into four treatment groups: 1) control (no treatment); 2) PDL irradiation only; 3) 5.0 mg RA (all-trans retinoid, 5.0 mg/kg per day, intraperitoneally [IP]); and (4) PDL + 0.5 mg RA (0.5 mg/kg per day, IP). The PDL irradiation was conducted at day 0 and 15, whereas the RA treatment was continued for 27 days. Tumor burden was measured over time.. The lesions in all of three treatment groups grow more slowly than the untreated controls. The combination treatment of PDL and RA had the greatest inhibitory effect on tumors.. This study suggests that combination treatment of PDL and low-dose RA is more effective than high-dose RA alone in the chemoprevention of HNSCC in a hamster cheek-pouch model, so that it should allow greatly improved tolerance of this regimen.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cheek; Cricetinae; Disease Models, Animal; Laser Therapy; Male; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; Prospective Studies; Random Allocation; Tretinoin

Vitamin A derivatives modulate the inflammatory phase in wound healing. Retinoic acid can restore decreased tensile strength and collagen content in steroid- or diabetes-impaired wounds. It is hypothesized that retinoic acid can lead to accelerated healing with improved breaking strength in unimpaired incisional wounds.. Skin incisions were made in 45 CD-1 mice. The sutured wounds were treated once daily with topical all-trans-retinoic acid 0.1% (n = 15), vehicle ointment (n = 15), or left untreated (n = 15). Skin biopsies at 1-, 2-, and 3-week intervals were examined using hematoxylin and eosin (H&E), Masson's trichrome, and immunoperoxidase staining methods. Wound breaking strength was determined by biomechanical analysis.. Incisions treated with retinoic acid exhibited a significantly reduced breaking strength at week 1 when compared to the vehicle and control group. Histologic examination showed a prolonged inflammatory reaction with abundant deposition of granulation tissue. Despite an increased fibroplastic proliferation in the tretinoin-treated wounds, the production of collagen was diminished.. Topical retinoic acid does not enhance the healing of unimpaired incisional wounds. The inadequate tensile strength in the early phase of the healing process is possibly the result of an increased dermal inflammatory response and the decreased collagen content. Although these adverse effects disappeared by 3 weeks postwounding, we found no discernible benefit of supplemental retinoic acid in unimpaired wounds.

Topics: Administration, Topical; Animals; Collagen; Disease Models, Animal; Male; Mice; Skin; Tensile Strength; Tretinoin; Wound Healing; Wounds, Stab

To observe the effect of retinoic acid on induction of osteoporotic model in rats and analyze the mechanism therein involved.. SD rats were treated with retinoic acid 80 mg/(kg x d) by gastrogavage for 15 days to induce osteoporosis and were killed in batches at 0, 30 and 60 days after drug withdrawal. The levels of Ca, P, BGP, E2, IGF-1, AKP and TRAP in serum were assayed, the collagen and proteoglycan contents of bone and bone mineral density (BMD) were determined, and the morphological changes in cancellous and cortical bone and growth plate cartilage (GPC) of femurs from the experimental rats were observed.. After 15 days of induction by retinoic acid, the serum E2 and BGP contents of rats were obviously decreased, the activities of AKP and TRAP were significantly increased, and the levels of BMD were lowered. The masses of spongy bone and cortical bone of femurs from the rats were decreased, and the number of chondrocytes in GPC was reduced. At 30 days, after drug withdrawal, the masses of spongy bone and cortical bone of femurs from the osteoporotic model rats still showed reduction; the activities of AKP in serum were lower than those at 15 days after drug redrawal, but were still higher than those of normal group rats; the chondrocytes in GPC were increased, the serum BGP and Ca contents were increased. At 60 days, after drug withdrawal, only the masses of femoral spongy bone of the osteoporotic model rats continuously showed obvious reduction, the other indices, including BGP, E2, AKP, TRAP and the masses of cortical bone, showed no significant difference between the two groups.. The short-term effect of retinoic acid on induction of rat's osteoporotic model was noticeable, but the long-term effect was not so good, and the bone loss of spongy bone existed longer and was more obvious than that of cortical bone.

Topics: Alkaline Phosphatase; Animals; Disease Models, Animal; Estradiol; Female; Insulin-Like Growth Factor I; Osteoporosis; Rats; Rats, Sprague-Dawley; Tretinoin

Differentially Expressed Nucleolar TGF-beta1 Target (DENTT) is a new member of the TSPY/TSPY-like/SET/NAP-1 (TTSN) superfamily whose mRNA is induced by TGF-beta1 in TGF-beta1-responsive human lung cancer cells. Monkey DENTT mRNA contains a 2085-bp open reading frame that encodes a predicted polypeptide of 695 amino acids with five nuclear localization signals, two coiled-coil regions, and a domain that shows significant identity to a region that defines the TTSN superfamily. RT-PCR amplification and Western blot analyses showed DENTT mRNA and protein in adult monkey tissues, including the adrenal gland, cerebral cortex, and ovary. Immunohistochemical staining showed that numerous neurons were intensely immunoreactive for DENTT, as were anterior pituitary secretory cells, thyroid follicular cells, and smooth muscle cells of arteries and lung bronchial walls. DENTT expression was also prominent in monkey bronchiolar-alveolar adenomas and cell lines. While the addition of TGF-beta1 or retinoic acid to monkey normal lung bronchial 12MBr6 cells and human lung cancer NCI-H727 cells increased DENTT protein production, TGF-beta1 together with retinoic acid resulted in a more sustained increase in DENTT production than with TGF-beta1 or retinoic acid alone. Transient transfection studies showed that ectopic DENTT expression significantly increased TGF-beta1-responsive 3TP-Lux and CAGA12-Lux reporter transcription in 12MBr6 and NCI-H727 cells with TGF-beta1 addition, while ectopic DENTT expression had no significant effect on the transcription of a retinoic acid-responsive element reporter in the presence of retinoic acid or TGF-beta1. These findings suggest new possibilities for DENTT as a TGF-beta1-regulated, but not a retinoic acid-regulated member of the TTSN superfamily in primate physiology.

Topics: Adrenal Glands; Amino Acid Sequence; Animals; Base Sequence; Blotting, Southern; Blotting, Western; Cell Line; Cell Nucleus; Cerebral Cortex; Chlorocebus aethiops; Cytoplasm; Disease Models, Animal; DNA Primers; DNA-Binding Proteins; Female; Humans; Immunohistochemistry; Lung; Lung Neoplasms; Macaca; Molecular Sequence Data; Myocytes, Smooth Muscle; Nuclear Proteins; Ovary; Reverse Transcriptase Polymerase Chain Reaction; Sequence Analysis, DNA; Sequence Homology; Thyroid Gland; Transcription, Genetic; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tretinoin

We investigated the preventive effects of a synthetic acyclic retinoid, NIK-333, on the early and late events of hepatocarcinogenesis in male F344 rats treated with 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB). NIK-333 was administered once a day on consecutive days at a dose of 10, 40, or 80 mg/kg body weight along with the supplementation with 3'-MeDAB-containing diet for 16 wk. Animals from each group were sacrificed at 4 and 16 wk after the commencement of the experiment to determine the effect of NIK-333 on the early and late stages of carcinogenesis, respectively. NIK-333 suppressed the emergence of both oval-like cells expressing transforming growth factor (TGF)-alpha, putative progenitors of hepatocellular carcinoma (HCC), and activated hepatic stellate cells, major matrix-producing cells of the liver, in the early stage and inhibited the incidence of HCC in the late phase. These results suggest that NIK-333 is a promising drug for the chemoprevention of HCC by uniquely suppressing the early events of hepatocarcinogenesis, that is, development of both oval-like cells and fibrogenesis.

Topics: Actins; Adenoma; Animals; Antineoplastic Agents; Carcinoma; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Fibrosis; Liver; Liver Neoplasms, Experimental; Male; Methyldimethylaminoazobenzene; Rats; Rats, Inbred F344; Retinoids; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transforming Growth Factor alpha; Tretinoin

Hepatocellular carcinoma (HCC) is common worldwide and growing in importance in the West. HCC often occurs against a background of liver disease, tends to present at an advanced stage, and has a poor prognosis, suggesting that it is an ideal target for chemoprevention. We sought to identify in an animal model chemopreventive agents for HCC that might be tested in human subjects. To this end, we induced liver tumors by injecting ethyl-nitrosourea in 6-week-old male B6C3F1 mice. Two chemopreventive agents were administered over a period of 60 weeks: tamoxifen (420 mg/kg feed) and a retinoid, 13-cis-retinoic acid (200 mg/kg feed). Animals were killed at 60 weeks and their livers examined for HCC and premalignant lesions. All liver lesions (altered foci, adenomata, HCC) occurred significantly less frequently in the tamoxifen-treated group than the group given only ethylnitrosourea (HCC developed in 2 of 47 (4%) vs 11 of 44 (25%); P < .001). On the other hand, retinoic acid appeared to increase the number of liver tumors, and in 2 animals angiosarcoma developed. Tamoxifen significantly decreased the incidence of chemical hepatocarcinogenesis in this model, suggesting an important role for estrogens in the pathogenesis of HCC and suggesting that it should be tested in human beings as a chemopreventive agent against HCC.

Topics: Adenoma, Liver Cell; Animals; Anticarcinogenic Agents; Carcinoma, Hepatocellular; Chemoprevention; Disease Models, Animal; Ethylnitrosourea; Liver Neoplasms, Experimental; Male; Mice; Mice, Inbred Strains; Precancerous Conditions; Tamoxifen; Tretinoin

The prevention of human neural tube defects by folic acid administration and the potential for fetal surgical intervention for myelomeningocele (MMC) have renewed interest in the molecular pathways and pathophysiology of spina bifida. Animal models for assessment of the early developmental biology and pathophysiology of this lesion are needed. The goal of this study was to develop and characterize a non-surgical rat model of MMC. Time-dated Sprague-Dawley rats were gavage fed different doses of retinoic acid (RA) dissolved in olive oil at E10 (maternal n = 55, fetal n = 505). Control animals received olive oil alone (maternal n = 20, fetal n = 265) or were untreated (maternal n = 5, fetal n = 63). Fetuses were analyzed by detailed histopathology and MRI. Overall, isolated MMC occurred in 60.7% (307/505) of RA-exposed fetuses and no controls. Histopathology confirmed the entire spectrum of severity observed in human MMC, ranging from exposure of the cord with intact neural elements to complete cord destruction. MRI of the brain of MMC fetuses confirmed structural changes similar to humans with Arnold-Chiari malformation, including downward displacement of the cerebellum to just above the foramen magnum and compression of the developing medulla into a small posterior fossa. In conclusion, the RA-induced rat model of MMC is developmentally and anatomically analogous to human MMC. This relatively efficient and cost-effective model of MMC should facilitate investigation of the developmental biology and pathophysiology of MMC, and may be useful for the evaluation of further strategies for prenatal treatment.

Topics: Abnormalities, Drug-Induced; Animals; Antineoplastic Agents; Arnold-Chiari Malformation; Brain; Cranial Fossa, Posterior; Disease Models, Animal; Female; Fetus; Magnetic Resonance Imaging; Meningomyelocele; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Spinal Cord; Spinal Dysraphism; Tretinoin

We induced neural cells by treating cynomolgus monkey embryonic stem (ES) cells with retinoic acid. The treated cells mainly expressed betaIIItubulin. They further differentiated into neurons expressing neurofilament middle chain (NFM) in elongated axons. Half of the cells differentiated into Islet1+ motoneurons in vitro. The monkey ES-derived neural cells were transplanted to hemiplegic mice with experimental brain injury mimicking stroke. The neural cells that had grafted into periventricular area of the mice distributed extensively over the injured cortex. Some of the transplanted cells expressed the neural stem/progenitor marker nestin 2 days after transplantation. The cells expressed markers characteristic of mature motoneurons 28 days after transplantation. Mice with the neural cell graft gradually recovered motor function, whereas control animals remained hemiplegic. This is the first demonstration that neural cells derived from nonhuman primate ES cells have the ability to restore motor function in an animal model of brain injury.

Topics: Animals; Biomarkers; Brain Damage, Chronic; Cell Differentiation; Cell Line; Cell Movement; Cerebral Infarction; Disease Models, Animal; Female; Graft Survival; Hemiplegia; Intermediate Filament Proteins; Macaca fascicularis; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Nestin; Neurofilament Proteins; Neurons; Recovery of Function; Stem Cell Transplantation; Stem Cells; Stroke; Treatment Outcome; Tretinoin

Although normal coronary artery embryogenesis is well described in the literature, little is known about the development of coronary vessels in abnormal hearts.. We used an animal model of retinoic acid (RA)-evoked outflow tract malformations (e.g., double outlet right ventricle [DORV], transposition of the great arteries [TGA], and common truncus arteriosus [CTA]) to study the embryogenesis of coronary arteries using endothelial cell markers (anti-PECAM-1 antibodies and Griffonia simplicifolia I (GSI) lectin). These markers were applied to serial sections of staged mouse hearts to demonstrate the location of coronary artery primordia.. In malformations with a dextropositioned aorta, the shape of the peritruncal plexus, from which the coronary arteries develop, differed from that of control hearts. This difference in the shape of the early capillary plexus in the control and RA-treated hearts depends on the position of the aorta relative to the pulmonary trunk. In both normal and RA-treated hearts, there are several capillary penetrations to each aortic sinus facing the pulmonary trunk, but eventually only 1 coronary artery establishes patency with 1 aortic sinus.. The abnormal location of the vessel primordia induces defective courses of coronary arteries; creates fistulas, a single coronary artery, and dilated vessel lumens; and leaves certain areas of the heart devoid of coronary artery branches. RA-evoked heart malformations may be a useful model for elucidating abnormal patterns of coronary artery development and may shed some light on the angiogenesis of coronary artery formation.

Topics: Animals; Biomarkers; Coronary Vessel Anomalies; Disease Models, Animal; Endothelial Cells; Female; Heart Ventricles; Mice; Mice, Inbred Strains; Pregnancy; Transposition of Great Vessels; Tretinoin; Truncus Arteriosus, Persistent

Tethered spinal cord is frequently associated with anorectal malformations (ARMs). However, it remains unknown how the tethered spinal cord develops and relates to the severity of ARM. We studied the development of the spinal cord in ARM mouse embryos induced by all-trans retinoic acid (ATRA).. Pregnant ICR-Slc mice were administered 100 mg/kg of ATRA on the ninth embryonic day (E9.0). Embryonic specimens were obtained from the uteri between E11.0 and E18.5. Midsagittal histologic sections focusing on the spinal cord and pelvis were prepared for immuonhistochemistry specific for neurofilament and Protein Gene Product 9.5 molecules.. More than 98% of ATRA-treated embryos demonstrated ARM with rectourethral or rectocloacal fistula. Normal embryos exhibited progressive ascent of the spinal cord from E14.5. However, in ARM embryos, the distal spinal cord ended with meningomyelocelelike or atypical hamartomatous lesions at E11.5 to E13.5, which later caused stretch force that damaged the spinal cord, resulting in tethered cord between E16.0 and E16.5.. In ATRA-induced ARM mouse embryos, tethered spinal cord was mostly established, accompanied by caudal neural maldevelopment, during early fetal development. This experimental model may be useful for researching detailed neuropathologic conditions in ARM children accompanied with tethered spinal cord.

Topics: Abnormalities, Multiple; Anal Canal; Animals; Disease Models, Animal; Embryonic Development; Female; Humans; Immunohistochemistry; Mice; Mice, Inbred ICR; Mutagens; Neural Tube Defects; Pregnancy; Rectum; Tretinoin

To investigate the potential role and the mechanism of PLZF-RARalpha/RARalpha-PLZF double fusion gene in the pathogenesis of acute promyelocytic leukemia (APL) in vivo at systematic biological level, PLZF-RARalpha/RARalpha-PLZF double transgenic mouse model was established by intercross; the integration and expression of fusion genes were analyzed by PCR and RT-PCR; the disease phenotype was detected by morphological and pathological examination of peripheral blood and bone marrow cells, as well as flow cytometry assays; the effects of ATRA with or without tricostatin A on bone marrow blast cells from PLZF-RARalpha/RARalpha-PLZF double TM were observed. The results showed that leukemia occurred in 5 PLZF-RARalpha/RARalpha-PLZF double TM 7, 7, 9, 11 and 11 months respectively, out of them two (40%) with classic APL features, the others (60%) with chronic myeloid leukemia through an observation period of 18 months. The leukemia occurrence of PLZF-RARalpha/RARalpha-PLZF TM was about 10%, which was similar to PLZF-RARalpha TM as that reported before. The latency was over 6 months, not earlier than PLZF-RARalpha TM only. No morphologic changes of PLZF-RARalpha/RARalpha-PLZF double TM blast cells to ATRA were observed, but increased cytoplasmic-nuclear ratio and nuclear condensation in bone marrow blast cells were found in combination of ATRA with tricostatin A. It is concluded that PLZF-RARalpha/RARalpha-PLZF double fusion gene transgenic mice have heterogeneity of pathogenesis. HDAC inhibitors such as trichostatin A, in combination with ATRA, induce differentiation of the blast/promyelocytic cells from PLZF-RARa/RARa-PLZF double TM, but not ATRA alone.

Topics: Animals; Antigens, CD34; Bone Marrow Cells; Cell Differentiation; Chorionic Gonadotropin; Disease Models, Animal; Female; Flow Cytometry; Humans; Hydroxamic Acids; Leukemia, Promyelocytic, Acute; Male; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Transgenic; Oncogene Proteins, Fusion; Pedigree; Receptors, Chemokine; Tretinoin

Models of emphysema produced by exposing animals to cigarette smoke (CS) have potential for use in testing treatments of this disease. To better characterize development of emphysema in an animal model, male and female mice of the B6C3F1 and A/J strains were exposed to CS at 250 mg total particulate material (TPM)/m3 for 15 weeks. Emphysema was evident in both strains of mice to differing degrees of severity. The CS-induced increase in the mean linear intercept (normalized to BW) of A/J mice was 51% greater than the control value, while CS-exposed B6C3F1 had an increase of 38% in this morphometric measurement of alveolar air space enlargement. In separate experiments, female B6C3F1 mice and male A/J mice were exposed to CS for 32 weeks and 15 weeks, respectively, and were then used to test the efficacy of all trans-retinoic acid (ATRA) treatments to ameliorate emphysema lesions. Following CS exposure, the B6C3F1 mice were treated once daily for 14 days in a 3-week period by nose-only inhalation exposure to aerosols of 180 or 1,800 mg-minutes ATRA/m3. The A/J mice were treated once daily, 4 days/week, for three weeks by either intraperitoneal injection of ATRA (0.5 or 2.5 mg/kg) or inhalation exposure to ATRA (3,600 or 18,000 mg-minutes/m3). Neither the injections nor inhalation exposures of ATRA in either strain of mouse caused reversal of the emphysema. In summary, CS-induced emphysema was more severe in A/J mice than in B6C3F1 mice. Treatment with ATRA did not reverse emphysema in either strain of CS-exposed mice.

Topics: Administration, Inhalation; Analysis of Variance; Animals; Disease Models, Animal; Female; Injections, Intraperitoneal; Male; Mice; Mice, Inbred Strains; Nicotiana; Pulmonary Emphysema; Smoke; Species Specificity; Tretinoin

Congenital diaphragmatic hernia (CDH) is a serious medical condition in which the developing diaphragm forms incompletely, leaving a hole through which the abdominal contents can enter the thoracic space and interfere with lung growth. A perturbation of the retinoid system has been linked to the etiology of CDH. This includes findings that nitrofen, which induces CDH in rodents, inhibits the key enzyme for retinoic acid (RA) production, retinaldehyde dehydrogenase-2 (RALDH2) in vitro. Published studies indicate that antenatal vitamin A administration on gestational day (D) 12 in the nitrofen model of CDH reduced the severity and incidence of right-sided defects and lung hypoplasia. In this study, we administered nitrofen on D8, to include the induction of clinically more prevalent left-sided defects, and examined the efficacy of several vitamin A administration paradigms to gain insights into the developmental stage of susceptibility. Furthermore, we tested the hypothesis that administration of RA, the product of RALDH2 activity, is more potent than administering the substrate, vitamin A, in reducing the incidence of CDH. The incidence of CDH was reduced from approximately 54% (nitrofen alone) to approximately 32% with vitamin A treatment. The efficacy of RA treatment was very marked, with a reduction in the incidence of CDH to approximately 15%. Administration of vitamin A or RA on approximately D10 was most effective. These data lend further support for the potential involvement of retinoid signaling pathways and the etiology of CDH and support data from in vitro studies demonstrating a nitrofen-induced suppression of RALDH2.

Topics: Animals; Animals, Newborn; Disease Models, Animal; Female; Hernia, Diaphragmatic; Incidence; Pesticides; Phenyl Ethers; Pregnancy; Rats; Rats, Sprague-Dawley; Tretinoin; Vitamin A

Dopamine receptor agonists are protective in different models of neurodegeneration by both receptor-dependent and -independent mechanisms. We used SH-SY5Y cells, differentiated into neuron-like type, to evaluate if cabergoline, a dopamine D2 receptor agonist endowed with anti-oxidant activity, protects the cells against ischemia (oxygen-glucose deprivation model). Cabergoline protected the cells from ischemia-induced cell death in a concentration-dependent manner (EC(50)=1.2 microM), as demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) release, and fluorescein diacetate-propidium iodide staining. This effect, observed even when the drug was added after oxygen-glucose deprivation, was not mediated by either dopamine D2 receptor activation or anti-apoptotic Bcl-2 protein over-expression (Western blotting analysis), but was linked to a reduction in cellular free radical loading (2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining) and membrane lipid peroxidation (thiobarbituric acid-reacting test). In conclusion, cabergoline protects in vitro neurons against ischemia-induced cell death, suggesting its possible use in the therapy of other neurodegenerative diseases in addition to Parkinson's disease.

Topics: Animals; Antioxidants; Cabergoline; Cell Death; Cell Hypoxia; Cell Line, Transformed; Cell Line, Tumor; Cell Survival; Disease Models, Animal; Dopamine Agonists; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Ergolines; Free Radical Scavengers; Free Radicals; Gene Expression; Genes, bcl-2; Glucose; Haloperidol; Humans; Ischemia; Neurons; Thiobarbituric Acid Reactive Substances; Time Factors; Tretinoin; Vitamin E

The question of how alterations in cell behavior produced by retinoic acid (RA) influenced the development of skeletogenic mesenchyme of the limb bud was examined in this study. Our established model was employed, which involves treatment of pregnant mice with a teratogenic dose of RA (100 mg/kg) on 11 days postcoitum (dpc) resulting in a severe truncation of all long bones of the forelimbs in virtually every exposed fetus. It is shown that RA, administered at a stage to induce phocomelia in virtually all exposed embryos, resulted in immediate appearance of enhanced cell death within the mesenchyme in the central core of the limb bud, an area destined for chondrogenesis. The central core mesenchyme, which in the untreated limb buds experiences a sharp decline in cell proliferation heralding the onset of chondrogenesis, demonstrated a reversal of the process; this mesenchyme maintained a higher rate of cell proliferation upon RA exposure. These events resulted in a truncation and disorganization of the chondrogenic anlage, more pronounced in zeugopodal mesenchyme than in the autopod. We conclude that an inhibition of chondrogenesis was secondary to a disruption in cellular behavior caused by RA, a likely consequence of misregulation in the growth factor signaling cascade.

Topics: Abnormalities, Drug-Induced; Administration, Oral; Animals; Apoptosis; Cell Proliferation; Chondrogenesis; Disease Models, Animal; Ectromelia; Female; Forelimb; Limb Buds; Male; Mesoderm; Mice; Mice, Inbred Strains; Pregnancy; Teratogens; Tretinoin

The implementation of cell replacement therapies for Huntington's disease using multipotent neural stem cells (NSCs) requires the specific differentiation into gamma-aminobutyric acid (GABA) neuronal subtype before transplantation. Here we present an efficient culture procedure that induces stable GABAergic neurons from the immortalized striatal neural stem cell line ST14A. This process requires sequential retinoic acid treatment and KCl depolarization. Initial addition of 10 microM retinoic acid increased cell survival and promoted neuronal differentiation. Subsequent stimulation with 40 mM KCl induced specific differentiation into GABAergic neurons, yielding 74% of total cultured cells. KCl-evoked Ca(2+) influx reduced cell proliferation and nestin expression, and induced neurite outgrowth and GABAergic markers as well as GABA contents, release, and uptake. Characterization of the integration, survival, and phenotype of these predifferentiated GABAergic neurons following transplantation into the adult brain in a model of Huntington's disease revealed long-term survival in quinolinate-lesioned striata. Under these conditions, cells maintained their GABAergic phenotype and elaborated neurite processes with synaptic contacts with endogenous neurons. In conclusion, we have generated a homogeneous population of functional GABAergic neurons from a neural stem cell line, which survive and maintain their acquired fate in vivo. These data may lend support to the possibility of cell replacement therapies for Huntington's disease using neural stem cells.

Topics: Animals; Cell Differentiation; Cell Line; Cell Proliferation; Cells, Cultured; Disease Models, Animal; gamma-Aminobutyric Acid; Graft Survival; Huntington Disease; Neurites; Neurons; Neurotoxins; Phenotype; Potassium Chloride; Rats; Stem Cell Transplantation; Stem Cells; Tretinoin

Defects very similar to those seen in infants born with congenital diaphragmatic hernias can be induced in rodents by the administration of the teratogen nitrofen. There is an interest in understanding the biochemical mechanisms of nitrofen's actions in hopes of gaining insights into the etiology of congenital diaphragmatic hernia. In this study, we test the hypothesis that nitrofen is acting to perturb the retinoid signaling pathway by utilizing genetically engineered mice that have the lacZ reporter gene linked to a retinoic acid response element (RARE). We demonstrate a pronounced suppression of RARE-lacZ expression by nitrofen in vitro (by approximately 64%) and in vivo (by approximately 43%).

Topics: Animals; beta-Galactosidase; Disease Models, Animal; Drug Interactions; Gene Expression; Herbicides; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; In Vitro Techniques; Lac Operon; Mice; Phenyl Ethers; Response Elements; Teratogens; Tretinoin

Transgenic mice expressing PML-RARalpha in early myeloid cells under control of human cathepsin G regulatory sequences all develop a myeloproliferative syndrome, but only 15% to 20% develop acute promyelocytic leukemia (APL) after a latent period of 6 to 14 months. However, this transgene is expressed at very low levels in the bone marrow cells of transgenic mice. Because the transgene includes only 6 kb of regulatory sequences from the human cathepsin G locus, we hypothesized that sequences required for high-level expression of the transgene might be located elsewhere in the cathepsin G locus and that a knock-in model might yield much higher expression levels and higher penetrance of disease. We, therefore, targeted a human PML-RARalpha cDNA to the 5' untranslated region of the murine cathepsin G gene, using homologous recombination in embryonic stem cells. This model produced a high-penetrance APL phenotype, with more than 90% of knock-in mice developing APL between 6 and 16 months of age. The latent period and phenotype of APL (including a low frequency of an interstitial deletion of chromosome 2) was similar to that of the previous transgenic model. Remarkably, however, the expression level of PML-RARalpha in bone marrow cells or APL cells was less than 3% of that measured in the low-penetrance transgenic model. Although the explanation for this result is not yet clear, one hypothesis suggests that very low levels of PML-RARalpha expression in early myeloid cells may be optimal for the development of APL in mice.

Topics: Animals; Antigens, CD34; Antineoplastic Agents; Biomarkers; Cathepsin G; Cathepsins; Cell Differentiation; Chromosomes, Mammalian; Disease Models, Animal; Female; Gene Deletion; Gene Dosage; Humans; Leukemia, Promyelocytic, Acute; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neoplasm Proteins; Oncogene Proteins, Fusion; Penetrance; Recombination, Genetic; RNA, Messenger; Serine Endopeptidases; Tretinoin

During formation of the secondary palate, clefting may result when critical developmental events are altered. The purpose of this study was to reduce the incidence of retinoic acid (RA)-induced cleft palate (CP) in mice by the co-administration of folic acid (FA), methionine (ME) or a combination of both.. Four groups of time-pregnant Swiss Webster mice were injected intraperitoneally with 50 mg/kg RA on gestational day (GD) 10. Likewise, 4.0 mg/kg FA and 187 mg/kg ME were administered on GD 8-11. The experiment included a control group (RA plus H2O) and three experimental groups, (RA plus therapeutic doses of FA, ME, or FA + ME). Necropsies were carried out on GD 18 and pups were analyzed for teratogenic effects.. Litters that received no therapy exhibited 100% CP with individual pups showing 76% susceptibility. Each therapy administered separately reduced the frequency of CP to approximately 6%, and the combination of FA and ME completely prevented the occurrence of RA-induced cleft palate (0%). A second experiment was conducted in which therapy levels were decreased by 25%. Litters that did not receive therapy experienced 100% clefting and individual pups exhibited CP at 86%. These therapies administered separately did not alter significantly the frequency of cleft palate. The combined doses of FA and ME, however, lowered significantly the frequency of cleft palate to 46%. Decreases in limb and tail defects with FA + ME therapy were also observed in both experiments.. Although FA and ME, at appropriate levels, can reduce individually the frequency of RA-induced cleft palate and other defects in mice, the results from the present study suggest that there is an additive interaction between the two therapeutic agents that can reduce further the teratogenic impact of RA. Further studies are needed to assess the mechanism of action of concomitant doses of FA and ME in the reduction of drug-induced birth defects.

Topics: Abnormalities, Drug-Induced; Animals; Bone and Bones; Cleft Palate; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Female; Folic Acid; Injections, Intraperitoneal; Methionine; Mice; Pregnancy; Teratogens; Tretinoin

We have investigated the effects of the low-toxic retinoid, all-trans retinoyl beta-glucuronide (RAG) alone and in combination with the phenylacetate (PA) derivative 4-chloro-phenylacetate (4-CPA) on the human neuroblastoma cell line, LA-N-5. In vitro studies demonstrated that RAG and 4-CPA treatments alone showed differentiation-inducing activity on LA-N-5 cells, with 4-CPA found to be about three-fold more potent than the PA parent compound in inducing morphologic differentiation and growth inhibition. As previously reported for retinoic acid (RA) and PA, RAG and 4-CPA were significantly more effective in their antiproliferative effects on the cells than either agent alone. Pharmacologic studies of 4-CPA in mice demonstrated that blood plasma levels reached peak concentrations 4 h after bolus administration of the compound and showed slow clearance characteristics with an apparent half-life of 4-8 h. As opposed to PA, 4-CPA was found to be essentially odourless and readily consumed in drinking water, giving rise to steady-state blood plasma levels of 4-CPA in the near mM range. Continuous consumption of 4-CPA in this manner for up to 5 months demonstrated no apparent adverse effects on the mice. Long-term RAG- and/or 4-CPA-treatment of nude mice injected with LA-N-5 cells demonstrated that both compounds alone exhibit potent antitumour activity. Together, RAG plus 4-CPA was the most effective treatment for inhibiting established tumour growth. In contrast, 4-CPA alone was equally as effective as the combination for preventing tumour development. The potent in vivo antitumour effects of 4-CPA could not be accounted for by the known ability of PA compounds to induce expression of the RA nuclear receptor beta (RARbeta) suppressor gene. Taken together, these findings demonstrate the possibility that RAG and/or 4-CPA may serve as effective, less-toxic alternatives to 13-cis RA, which is presently being utilised for nb therapy.

Topics: Administration, Oral; Animals; Cell Division; Disease Models, Animal; Drug Therapy, Combination; Female; Humans; Mice; Mice, Nude; Neuroblastoma; Phenylacetates; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin; Tumor Cells, Cultured

Despite improved molecular characterization of malignancies and development of targeted therapies, acute leukemia is not curable and few patients survive more than 10 years after diagnosis. Recently, combinations of different therapeutic strategies (based on mechanisms of apoptosis, differentiation and cytotoxicity) have significantly increased survival. To further improve outcome, we studied the potential efficacy of boosting the patient's immune response using specific immunotherapy. In an animal model of acute promyelocytic leukemia, we developed a DNA-based vaccine by fusing the human promyelocytic leukemia-retinoic acid receptor-alpha (PML-RARA) oncogene to tetanus fragment C (FrC) sequences. We show for the first time that a DNA vaccine specifically targeted to an oncoprotein can have a pronounced effect on survival, both alone and when combined with all-trans retinoic acid (ATRA). The survival advantage is concomitant with time-dependent antibody production and an increase in interferon-gamma (IFN-gamma). We also show that ATRA therapy on its own triggers an immune response in this model. When DNA vaccination and conventional ATRA therapy are combined, they induce protective immune responses against leukemia progression in mice and may provide a new approach to improve clinical outcome in human leukemia.

Topics: Animals; Antineoplastic Agents; Cancer Vaccines; Disease Models, Animal; Humans; Leukemia, Promyelocytic, Acute; Mice; Mice, Transgenic; Neoplasm Proteins; Oncogene Proteins, Fusion; Tretinoin; Vaccines, DNA

Topics: Animals; DiGeorge Syndrome; Disease Models, Animal; Fibroblast Growth Factor 8; Fibroblast Growth Factors; Humans; Pharynx; Tretinoin; Vascular Endothelial Growth Factor A

The retinoic acid (RA) signal, produced locally from vitamin A by retinaldehyde dehydrogenase (Raldh) and transduced by the nuclear receptors for retinoids (RA receptor and 9-cis-RA receptor), is indispensable for ontogenesis and homeostasis of numerous tissues. We demonstrate that Raldh3 knockout in mouse suppresses RA synthesis and causes malformations restricted to ocular and nasal regions, which are similar to those observed in vitamin A-deficient fetuses and/or in retinoid receptor mutants. Raldh3 knockout notably causes choanal atresia (CA), which is responsible for respiratory distress and death of Raldh3-null mutants at birth. CA is due to persistence of nasal fins, whose rupture normally allows the communication between nasal and oral cavities. This malformation, which is similar to isolated congenital CA in humans and may result from impaired RA-controlled down-regulation of Fgf8 expression in nasal fins, can be prevented by a simple maternal treatment with RA.

Topics: Aldehyde Oxidoreductases; Animals; Animals, Newborn; Base Sequence; Choanal Atresia; Disease Models, Animal; DNA; Female; Gene Targeting; Genes, Lethal; Humans; Isoenzymes; Maternal-Fetal Exchange; Mice; Mice, Knockout; Pregnancy; Retinal Dehydrogenase; Tretinoin

To evaluate the effect and molecular mechanism of retinoic acid (RA) in preventing experimental pulmonary emphysema in rats.. Thirty-six Wistar rats were randomly divided into three groups, the normal group(A), the model group (B) and the RA treated group (C). Rats in group B group were exposed to cigarette smoke, and group C was treated with RA. Pulmonary function indices and histopathological changes were evaluated. The enzymatic activity of gelatinases was measured by ELISA, and the expression of gelatinases and the proliferating cell nuclear antigen (PCNA) was examined by immunohistochemical method.. Compared with group A, group B presented significant differences in FEV(0.3),FEV(0.3)/FVC and FRC [(5.1 +/- 0.4) ml vs (6.0 +/- 0.3) ml, (71 +/- 10) ml/s vs (87 +/- 3) ml/s, (7.2 +/- 2.2) ml vs (2.9 +/- 1.1) ml (P < 0.01)];the enzymatic activity [(1.06 +/- 0.23)ng/ml vs (0.53 +/- 0.17)ng/ml, (0.960 +/- 0.230)ng/ml vs (0.300 +/- 0.090)ng/ml] and the expression of gelatinases were also markedly elevated(P < 0.01). In comparison with group B, the pulmonary function indices in group C [(5.2 +/- 0.4)ml, (81 +/- 5) ml/s, (6.1 +/- 2.7)ml/s] were improved (P < 0.05); the enzymatic activity [(0.83 +/- 0.23)ng/ml, (0.570 +/- 0.010)ng/ml] and the expression of gelatinases were decreased, while the PCNA index staining (93 +/- 4 vs 53 +/- 6) was increased (P < 0.01).. RA can prevent the development of pulmonary emphysema in rats.

Topics: Animals; Chemoprevention; Chronic Disease; Disease Models, Animal; Keratolytic Agents; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Proliferating Cell Nuclear Antigen; Pulmonary Emphysema; Rats; Rats, Wistar; Respiratory Function Tests; Tretinoin

To investigate the effects of all-trans retinoic acid (ATRA) on metastasis and its related proteins in human gastric cancer cells in vivo and in vitro.. Gastric cancer cells, MGC80-3 and SGC-7901, were inoculated into spleen subcapsule of nude mice, respectively. Nude mice were administered with ATRA (0.7 mg/kg, ig) every other day. Six weeks later, nude mice were sacrificed. All the tumors formed in spleen and in liver were removed. Some of them were fixed, and then embedded. Others were kept in liquid nitrogen for further use. Expression level of proteins in tumor and in cell was analyzed by Western blot. Microvessel in tumor section was shown by immunohistochemistry and adhesive ability of cell to amnion was measured by adhesion assay.. When inoculated nude mice were treated with ATRA, the xenograft tumors in spleen and metastatic tumors in liver were suppressed by 50 % respectively, and inhibition of microvessel formation in xenograft and metastatic tumors was also observed obviously. Although ATRA regulated expression of nm23 and mts1/p16 proteins at different patterns in vivo and in vitro, high ratio of nm23:mts1/p16 was in association with low adhesive activity of cells. In addition, ATRA induced ICAM-1 protein expression in vivo and in vitro.. ATRA inhibits the growth of xenograft tumors and their metastasis to liver. This process may be associated with regulation of metastatic related proteins, including nm23, mts1/p16, and ICAM-1 in vivo and in vitro.

Topics: Animals; Antineoplastic Agents; Cyclin-Dependent Kinase Inhibitor p16; Disease Models, Animal; Humans; Intercellular Adhesion Molecule-1; Mice; Mice, Inbred BALB C; Mice, Nude; Monomeric GTP-Binding Proteins; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms, Experimental; NM23 Nucleoside Diphosphate Kinases; Nucleoside-Diphosphate Kinase; Stomach Neoplasms; Transcription Factors; Tretinoin; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

FK228 [(E)-(1S,4S,10S,21R)-7-[(Z)-ethylidene]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo-[8,7,6]-tricos-16-ene-3,6,9,19,22-pentanone; FR901228, depsipeptide] is a novel histone deacetylase inhibitor that shows therapeutic efficacy in Phase I trials of patients with malignant lymphoma. However, its mechanism of action has not been characterized. In this study, we examined the in vitro and in vivo effects of FK228 on human lymphoma U-937 cells. FK228 very strongly inhibited the growth of U-937 cells with an IC(50) value of 5.92 nM. In a scid mouse lymphoma model, mice treated with FK228 once or twice a week survived longer than control mice, with median survival times of 30.5 (0.56 mg/kg) and 33 days (0.32 mg/kg), respectively (vs. 20 days in control mice). Remarkably, 2 out of 12 mice treated with FK228 (0.56 mg/kg once or twice a week) survived past the observation period of 60 days. The apoptotic population of U-937 cells time-dependently increased to 37.7% after 48 hr of treatment with FK228. In addition, FK228 induced G1 and G2/M arrest and the differentiation of U-937 cells to the CD11b(+)/CD14(+) phenotype. Expression of p21(WAF1/Cip1) and gelsolin mRNA increased up to 654- and 152-fold, respectively, after 24hr of treatment with FK228. FK228 caused histone acetylation in p21(WAF1/Cip1) promoter regions, including the Sp1-binding sites. In conclusion, (i) FK228 prolonged the survival time of scid mice in a lymphoma model, and (ii) the beneficial effects of FK228 on human lymphoma may be exerted through the induction of apoptosis, cell cycle arrest, and differentiation via the modulation of gene expression by histone acetylation.

Topics: Acetylation; Animals; Anti-Bacterial Agents; Antibiotics, Antineoplastic; Apoptosis; Cell Cycle; Cell Differentiation; Cholecalciferol; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Depsipeptides; Disease Models, Animal; Gelsolin; Histone Deacetylase Inhibitors; Histones; Humans; Leukemia; Lymphoma; Mice; Mice, SCID; Neoplasm Transplantation; Peptides, Cyclic; Promoter Regions, Genetic; RNA, Messenger; Tretinoin; U937 Cells; Xenograft Model Antitumor Assays

Since high anorectal malformations with fistulae in human embryos and fetuses of successive developmental stages have not been reported, the embryologic relationship between the rectal fistula (RF) and the genitourinary tract (GUT) in high anorectal agenesis (ARA) remains to be elucidated. This study investigates the developmental relationship between the RF and the GUT in male and female fetuses with high ARA using our established model for high ARA with fistula in mice. Pregnant mice received all-trans retinoic acid suspended in corn oil (5 mg/ml) 100 mg/kg i.p. on day 9 of pregnancy. All fetuses were removed from the uterus on a single day from days 12 to 18 of pregnancy. The caudal regions were analyzed histologically with hematoxylin and eosin staining. All fetuses examined had high ARA with fistula. On day 12 of pregnancy, an anomalous communication was seen between the urogenital sinus (UGS) and the rectum. In the affected female fetuses, on day 14 of pregnancy the paramesonephric (müllerian) ducts and müllerian tubercle were located above the rectocloacal fistula (RCF), and on day 18 of pregnancy the uterovaginal canal was located between the cloaca and the RCF. In the male fetuses, on day 14 of pregnancy the junction between the mesonephric (wolffian) duct and the UGS was located away from the junction between the rectum and the UGS. On day 18 of pregnancy the ejaculatory duct was located between the urinary bladder and the rectourethral fistula. The results of our experiment clearly show the embryologic relationship between the RF and the GUT with high ARA. The anomalous communication between the UGS and the rectum may interfere with normal caudal migration along the dorsal wall of the UGS at the junction between the UGS and the mesonephric or paramesonephric duct.

Topics: Anal Canal; Animals; Digestive System Abnormalities; Disease Models, Animal; Female; Fetus; Male; Mice; Pregnancy; Rectal Fistula; Rectum; Tretinoin; Urogenital Abnormalities

To determine whether the application of exogenous retinoic acid (RA) may induce the proliferation of retinal cells in adult rat.. Thirty-two healthy adult Sprague-Dawley (SD) rats were randomly divided into 4 groups. In Group 1 and Group 2, all-trans RA (5 microliter, 0.001 mol/L) was injected into the subretinal space. In Group 3 and Group 4, all-trans RA (10 microliter, 0.001 mol/L) was injected into epiretinal vitreous space. In the Group 1 and Group 3, transient ischemic-reperfusion injuries of the experimental eyes were induced by ligating ophthalmic artery prior to RA treatment. In the control group, 5 SD rats were treated by ischemia-reperfusion injuries but no exogenous RA application. The treated eyes were enucleated for light microscopic analysis and immunohistochemical assays after 2 - 4 weeks of RA application.. In group 1, the number of the retinal cells expressing rod-specific opsin marker in the subretinal space was significantly increased and the thickness of inner nuclear layer was also increased after the RA treatment for 16 days. However, no cell proliferation was detected in group 2. There were also no changes within population of retinal cells in Group 3 and Group 4 in which RA was injected into epiretinal vitreous space no matter under the ischemia-reperfusion or non-ischemia-reperfusion. In the control group, there were no significant morphological changes within the neural retinal layers as well as photoreceptor proliferation.. The application of RA in the subretinal space can induce photoreceptor proliferation in adult rat under an ischemic-reperfusion injury condition. It will provide a new idea for the regeneration of neural retinal cells.

Topics: Animals; Biomarkers; Cell Division; Disease Models, Animal; Keratolytic Agents; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Retinal Rod Photoreceptor Cells; Rod Opsins; Tretinoin

Our laboratory has demonstrated that treatment of MCF-7 breast cancer cells with melatonin (Mlt) followed 24h later with physiological concentrations of all-trans retinoic acid (atRA) results in apoptosis. These studies were extended into trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model. Initial studies conducted by feeding the animals 9-cis-retinoic acid (9cRA in the chow) and administering melatonin by subcutaneous injection in the late afternoon demonstrated that the combination of Mlt and 9cRA was able to significantly prevent tumor development, and that the combination was more efficacious that either Mlt or 9cRA alone. In this report, we conducted studies to determine if lower doses of 9cRA could be used in combination with Mlt while still maintaining anti-tumor activity and if the route of administration of 9cRA (bolus (gavage) v.s. chronic (chow) routes) affected its interaction with Mlt. The studies presented here demonstrate that significantly reduced doses of 9cRA can be used in combination with Mlt while maintaining anti-tumor efficacy. Furthermore, our studies demonstrate that 9cRA is equally effective when it is administered chronically (chow) or as a bolus (gavage). These data demonstrate that the combined use of Mlt and 9cRA produces additive or synergistic effects, which are more efficacious than 9cRA alone. This combination of Mlt and 9cRA could be a potentially useful clinical treatment regimen for breast cancer since it allows the use of lower doses of retinoic acid, thus, avoiding the toxic side effects associated with the use of high dose retinoids.

Topics: Administration, Oral; Alitretinoin; Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drug Synergism; Female; Injections, Subcutaneous; Mammary Neoplasms, Experimental; Melatonin; Methylnitrosourea; Rats; Rats, Sprague-Dawley; Tretinoin

Up-regulation of folate receptor (FR) type-beta in acute myelogenous leukemia (AML) by all-trans retinoic acid (ATRA) and its restricted normal tissue distribution makes it a potential target for therapeutic intervention. The FR-beta in peripheral blood granulocytes was unable to bind folate and appeared to have a variant GPI membrane anchor, evident from its insensitivity to phosphatidylinositol-specific phospholipase C but not nitrous acid. Granulocyte FR-beta lacked mutations, and neither deglycosylation nor detergent solubilization restored folate binding. The posttranslational modification causing its nonfunctionality was evidently absent in FR-beta from AML cells from patient marrow, which bound folate. From flow cytometric analysis of 78 AML bone marrow specimens of different subtypes, 68% expressed FR-beta, most of which were also CD34+. In model cell lines that are FR - (KG-1a, L1210, and Chinese hamster ovary [CHO]) or FR + (KG-1, L1210 JF, and recombinant CHO-FR-beta), selective FR-mediated binding and cytotoxicity was obtained using folate-coated liposomes encapsulating fluorescent calcein (f-L-calcein) and doxorubicin (f-L-DOX), respectively, which could be blocked by 1 mM free folic acid. In the FR-beta-expressing KG-1 human AML cells, treatment with ATRA further increased this specificity. In mouse ascites leukemia models generated using L1210JF or KG-1 cells, increased median survival times were obtained with f-L-DOX treatment compared to nontargeted L-DOX. In the KG-1 model, ATRA treatment increased the cure rate with f-L-DOX from 10% to 60%. The above combined data from our 2 laboratories further support the feasibility and potential usefulness of selective ATRA-facilitated liposomal drug delivery in FR-beta + AMLs.

Topics: Animals; Antigens, CD34; Antineoplastic Combined Chemotherapy Protocols; Carrier Proteins; Cell Death; Disease Models, Animal; Doxorubicin; Drug Delivery Systems; Drug Evaluation, Preclinical; Folate Receptors, GPI-Anchored; Folic Acid; Gene Expression Regulation; Humans; Leukemia, Myeloid, Acute; Liposomes; Mice; Receptors, Cell Surface; Survival Rate; Therapeutic Equivalency; Treatment Outcome; Tretinoin; Tumor Cells, Cultured

Retinoids are natural and synthetic analogues of the hormone retinoic acid. Systemic retinoid agonist therapy is usually associated with toxic side effects, such as mucocutaneous toxicity, which may be alleviated by the use of topical retinoid antagonists. We report the synthesis and biological activity of a new series of potent, RAR-specific antagonists substituted with phenylcyclohexene and phenylcyclohexadiene groups.

Topics: Animals; Benzoates; Cyclohexanes; Dermatitis, Irritant; Disease Models, Animal; Mice; Receptors, Retinoic Acid; Retinoids

All-trans retinoic acid (ATRA) has been introduced to the management of acute promyelocytic leukemia (APL) as a differentiation treatment. This drug not only causes complete remission, but also improves disseminated intravascular coagulation (DIC) without adding anticoagulants in APL. We have attempted to determine whether ATRA is effective against DIC in rat models induced by tissue factor (TF) or lipopolysaccharide (LPS), because the anticoagulant effect of ATRA has been considered to induce thrombomodulin upregulation and TF downregulation on endothelial cells as well as on APL cells. In male Wistar rats, DIC was induced by a 4-h infusion of thromboplastin (3.75 U/kg) or lipopolysaccharide (30 mg/kg). The rats were given ATRA orally each day at a dose of 100 mg/kg per day for 1 week before the injection of TF or LPS in ATRA treatment groups, or given low molecular weight heparin (LMWH) 10 min before the injection of TF or LPS (200 U/kg, bolus intravenously) in LMWH treatment groups. No significant changes in hemostatic parameters or markers of organ dysfunction were caused by the ATRA administration, while DIC was significantly improved by LMWH in the TF-induced model. DIC was significantly improved by both ATRA and LMWH in the LPS-induced model. These findings suggested that ATRA was useful for treating DIC only in the LPS-induced model, and that drug efficacy should be carefully assessed because the agents used to induce DIC considerably influenced the outcome.

Topics: Animals; Disease Models, Animal; Disseminated Intravascular Coagulation; Keratolytic Agents; Lipopolysaccharides; Male; Rats; Rats, Wistar; Thromboplastin; Tretinoin

This study examined the role of the pulsed-dye laser (PDL) at 585 nm coupled with retinoic acid at therapeutic (5.0 mg/kg) and nontherapeutic (0.5 mg/kg) doses to delay the progression of cancer with a two-hit approach. The existing vasculature is selectively targeted by the laser, whereas retinoic acid inhibits future angiogenesis.. Randomized, prospective study in a murine model.. Twenty-five athymic nude mice were inoculated with oral squamous cell cancers on six flank sites and randomly divided into five groups: 1) control subjects, 2) treatment with 0.5 mg/kg retinoic acid (RA 0.5), 3) treatment with 5.0 mg/kg retinoic acid (RA 5.0), 4) treatment with RA 0.5 + PDL, and 5) treatment with RA 5.0 + PDL. The PDL groups received irradiation after inoculation. The retinoic acid was administered daily. The tumors were counted and measured for 14 days.. The control group developed visible tumors in 50% of the inoculation sites at 3 days compared with 3 days (RA 0.5) and 4 days (RA 5.0) for the retinoic acid groups and 9 days (RA 0.5 + PDL) and 10 days (RA 5.0 + PDL) for the laser treatment groups. There was no tumor growth until day 7 in the RA 5.0 + PDL group. The tumor volume was statistically different between the treatment groups.. This study demonstrated the superiority of a single treatment with the PDL coupled with retinoic acid to delay the progression of cancer when compared with treatment with retinoic acid alone, thus introducing a novel strategy in cancer control.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Combined Modality Therapy; Data Interpretation, Statistical; Disease Models, Animal; Laser Therapy; Lithotripsy, Laser; Mice; Mice, Nude; Mouth Neoplasms; Neoplasm Transplantation; Neoplasms, Experimental; Prospective Studies; Random Allocation; Time Factors; Tretinoin

All-trans-retinoic acid (ATRA) has anti-fibrotic and antiinflammatory properties, and may be useful as a therapeutic agent in lung fibrosis. To test this hypothesis we investigated the effect of ATRA on bleomycin-induced lung fibrosis in Sprague-Dawley rats. Treatment groups included: (1) a single intratracheal (i.t.) instillation of bleomycin and daily intraperitoneal (i.p.) injection of 0.5 mg/kg per day ATRA; (2) i.t. bleomycin and i.p. ATRA, 2 mg/kg per day, (3) i.t. bleomycin and i.p. diluent (cottonseed oil); (4) i.t. saline and i.p. ATRA, 0.5 mg/kg per day, (5) i.t. saline and i.p. ATRA, 2 mg/kg per day; and (6) i.t. saline and i.p. diluent. Animals were studied 14 days after i.t. instillation. Lung injury was evaluated by total and differential cell count in bronchoalveolar lavage fluid, by a semi-quantitative morphological index of lung injury, and by biochemical analysis of lung hydroxyproline content. Overt signs of lung injury were apparent in bleomycin-treated rats by all measures. These changes were not affected by treatment with ATRA at either dose. This study does not support the use of ATRA to prevent or ameliorate lung fibrosis.

Topics: Animals; Antineoplastic Agents; Bleomycin; Disease Models, Animal; Injections, Intraperitoneal; Lung; Pulmonary Fibrosis; Random Allocation; Rats; Rats, Sprague-Dawley; Tretinoin

Vitamin A and its derivatives such as retinoic acid (RA) are important signaling molecules for morphogenesis of vertebrate embryos. Little is known, however, about morphogenetic factors controlling the development of the gastrointestinal tract and RA is likely to be involved. In the mouse, teratogenic doses of RA cause truncation of the embryonic caudal body axis that parallel the caudal regression syndrome as described in humans. These changes are often associated with anomalies of the lower digestive tract. Overlapping spatiotemporal expression of retinoic acid receptor-beta (RAR beta) and cellular retinol-binding protein I, CRBPI, with Hoxb5 and c-ret in the gut mesoderm imply possible cooperation required for proper neuromuscular development. To determine susceptibility and responsiveness of the developing gut and its neuromusculature to exogenous retinoids we used a mouse model of RA-induced caudal regression syndrome. The results showed that stage-specific RA treatment both in vivo and in vitro affected gut looping/rotation morphogenesis and growth of asymmetrical structures such as the cecum together with delayed differentiation of the gut mesoderm and colonization of the postcecal gut by neural crest-derived enteric neuronal precursors. These observations demonstrate that RA has a direct effect on gut morphogenesis and innervation.

Topics: Animals; Disease Models, Animal; Embryo, Mammalian; Female; Intestines; Lumbar Vertebrae; Mice; Muscles; Nervous System; Organ Culture Techniques; Pregnancy; Sacrum; Syndrome; Time Factors; Tretinoin

Sustained high output release of Nitric oxide (NO) as result of activation of inducible nitric oxide synthase (iNOS), and increased production of the antiproliferative/profibrotic cytokine transforming growth factor-beta1 (TGF-beta1) are well documented in glomerulonephritis. Modulation of iNOS activity and of TGF-beta1 production can therefore be viewed as anti-inflammatory strategies. The present study employed all-trans retinoic acid (atRA) which is known to have anti-inflammatory effects and to modulate expression of iNOS and TGF-beta1, in order to explore its effect on iNOS enzyme activity and TGF-beta1 production in anti-GBM antibody induced glomerulonephritis. Glomerulonephritis was induced in Lewis rats by injection of anti-GBM antibody. A group of nephritic rats were given daily administration of atRA for 14-16 days. Extent of proteinuria was assessed by measuring urine protein and creatinine excretion. iNOS enzyme activity was measured by calculating conversion of L[14C]arginine to L-[14C]citrulline in glomerular protein lysates. Levels of TGF-beta1 in glomerular protein lysates were measured by quantitative ELISA. Levels of proliferating nuclear antigen (PCNA), TGF-beta receptor II (TGFbeta-RII), and fibronectin were assessed by Western blot analysis. Glomerular iNOS activity in atRA treated nephritic animals was attenuated in comparison to that in nephritic controls that were not. Glomerular expression of PCNA was also reduced. Levels of TGF-beta1 were increased in glomeruli of atRA treated nephritic animals. In these animals, there was no change in glomerular levels of TGF-beta receptor II (TGFbeta-RII) or fibronectin. and there was no reduction in urine protein excretion. These results suggest that atRA attenuates iNOS activity and proliferation in glomeruli of nephritic animals. The failure of atRA treatment to reduce proteinuria could be due to the increase in TGF-beta1 levels and to inhibition of iNOS-driven NO production.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies; Autoantibodies; Cell Division; Disease Models, Animal; Glomerulonephritis; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Proliferating Cell Nuclear Antigen; Proteinuria; Rats; Rats, Inbred Lew; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tretinoin

To identify the function of these bone morphogenetic proteins (BMP) during pathogenesis of cleft palate, an experimental model was established in BALB/c mice. Cleft palate was induced by exposure to retinoic acid on embryonic day (E)12. The expression of BMP-2,3,4,5 mRNA in normal and abnormal embryonic palatal shelves was then examined from E13 to E16 by in situ hybridization. The results showed that BMP-4 mRNA was expressed strongly and uniformly in normal epithelial cells and dispersed mesenchymal cells on E13. BMP-2,5 mRNA expression appeared only in dispersed mesenchymal cells. With the development of shelves, the staining density of BMP-2,4,5 decreased gradually in mesenchymal cells outside of the condensation and increased inside the condensation. After shelves had fused on E16, no positive signals for BMP-2,4,5 were detected in dispersed mesenchymal cells, but their expression persisted in the condensation. Exposure to retinoic acid delayed the formation of the condensation and decreased BMP-2,4,5 mRNA dramatically in mesenchyme from E13 to E15. BMP-3 mRNA expression were almost negative in either control or retinoic acid-treated groups during all stages. It was concluded that spatial and temporal expression of BMP-2,4,5 was required during normal palatogenesis, and that a deficiency of their mRNA expression may contribute to the pathogenesis of cleft palate.

Topics: Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Protein 3; Bone Morphogenetic Protein 4; Bone Morphogenetic Protein 5; Bone Morphogenetic Proteins; Cleft Palate; Coloring Agents; Disease Models, Animal; Epithelial Cells; Gene Expression Regulation; Growth Substances; In Situ Hybridization; Mesoderm; Mice; Mice, Inbred BALB C; Palate; RNA, Messenger; Transforming Growth Factor beta; Tretinoin

The P19 embryonal carcinoma-derived cell line consists of undifferentiated multipotential cells, which irreversibly differentiate into mature neurons after exposure to retinoic acid (RA). In the present study, the authors genetically engineered P19 cells to produce glial cell line-derived neurotrophic factor (GDNF), and grafted the cells in a rat model that had been rendered parkinsonian.. Undifferentiated P19 cells were grown in vitro and transduced with GDNF complementary DNA. The level of GDNF released from the transduced cells was measured using an enzyme-linked immunosorbent assay, and its neurotrophic activities were assessed by testing the effects on rat embryonic dopamine (DA) neurons in culture. After having been exposed to RA for 48 hours and allowed to differentiate into postmitotic neurons, the GDNF gene-transduced cells were implanted into the midbrain of immunosuppressed rats. A unilateral nigrostriatal lesion was then induced by intrastriatal infusions of 6-hydroxydopamine. Immunohistochemical analyses performed 4 weeks postgrafting revealed that the GDNF-producing cells expressed several neuronal markers without evidence of overgrowth. The grafts expressed GDNF protein and prevented the death of nigral DA neurons. Furthermore, the GDNF-producing cells implanted 4 weeks after nigrostriatal lesions restored the expression of tyrosine hydroxylase in injured DA neurons and induced their dendritic sprouting.. The results indicate that the P19 cell line transduced with the GDNF gene can stably secrete functional levels of GDNF, even after being converted to postmitotic neurons. Because it is has been established that GDNF exerts trophic effects on DA neurons, the means currently used to deliver GDNF into the brain could be a viable strategy to prevent the death of nigral DA neurons in cases of Parkinson's disease.

Topics: Analysis of Variance; Animals; Carcinoma, Embryonal; Cell Death; Cell Differentiation; Cell Survival; Cells, Cultured; Dendrites; Disease Models, Animal; Dopamine; Follow-Up Studies; Gene Expression Regulation, Enzymologic; Genetic Engineering; Male; Nerve Growth Factors; Neuroglia; Neurons; Parkinson Disease; Rats; Rats, Sprague-Dawley; Regeneration; Stem Cells; Substantia Nigra; Transduction, Genetic; Tretinoin; Tumor Cells, Cultured; Tyrosine 3-Monooxygenase

Topics: Animals; Disease Models, Animal; Disease Progression; Instillation, Drug; Keratolytic Agents; Male; Pancreatic Elastase; Pulmonary Alveoli; Pulmonary Emphysema; Rats; Rats, Sprague-Dawley; Respiratory Function Tests; Tomography, X-Ray Computed; Trachea; Treatment Outcome; Tretinoin

The expression of midkine (MK) was investigated in pancreatic ductal hyperplasias, atypical hyperplasias and adenocarcinomas induced by N-nitrosobis(2-oxopropyl)amine (BOP) in hamsters, and in hamster ductal adenocarcinoma cell lines (HPD-1NR, -2NR and -3NR). MK mRNA was clearly overexpressed in invasive pancreatic duct adenocarcinomas (PCs) and the three cell lines as assessed by northern blot analysis, and MK protein expression increased from ductal hyperplasia through atypical hyperplasias, intraductal carcinomas and invasive PCs by immunohistochemistry. The extent of overexpression of MK mRNA in PCs was almost the same as in hamster whole embryonic tissue. MK is reported to be a retinoid-responsive gene, but MK mRNA expression was not affected by treatment with all-trans retinoic acid (tRA) or N-(4-hydroxyphenyl)retinamide (4-HPR) in HPD-1NR cells. The results thus suggest that MK expression is involved in the development and progression of pancreatic ductal adenocarcinomas induced by BOP in hamsters, with loss of upregulation by retinoic acid.

Topics: Animals; Antineoplastic Agents; Blotting, Northern; Carcinoma, Pancreatic Ductal; Carrier Proteins; Cell Division; Cells, Cultured; Cricetinae; Cytokines; Disease Models, Animal; Female; Fenretinide; Gene Expression; Immunohistochemistry; Mesocricetus; Midkine; Nitrosamines; Pancreatic Neoplasms; RNA, Messenger; Tretinoin

The high incidence and long latent period of prostate cancer make it an ideal target for chemoprevention. We have evaluated a series of agents for chemopreventive efficacy using a model in which hormone-dependent prostate cancers are induced in the Wistar-Unilever (WU) rat by sequential treatment with antiandrogen (cyproterone acetate), androgen (testosterone propionate), and direct-acting chemical carcinogen (N-methyl-N-nitrosourea), followed by chronic androgen stimulation (testosterone). This regimen reproducibly induces prostate cancers in high incidence, with no gross toxicity and a low incidence of neoplasia in the seminal vesicle and other non-target tissues. Dehydroepiandrosterone (DHEA) and 9-cis-retinoic acid (9-cis-RA) are the most active agents identified to date. DHEA inhibits prostate cancer induction both when chronic administration is begun prior to carcinogen exposure, and when administration is delayed until preneoplastic prostate lesions are present. 9-cis-RA is the most potent inhibitor of prostate carcinogenesis identified; a study to determine the efficacy of delayed administration of 9-cis-RA is in progress. Liarozole fumarate confers modest protection against prostate carcinogenesis, while N-(4-hydroxyphenyl)retinamide (fenretinide), alpha-difluoromethylornithine, oltipraz, DL-alpha-tocopherol acetate (vitamin E), and L-selenomethionine are inactive. Chemoprevention efficacy evaluations in the WU rat will support the identification of agents that merit study for prostate cancer chemoprevention in humans.

Topics: Alitretinoin; Animals; Antineoplastic Agents; Dehydroepiandrosterone; Disease Models, Animal; Immunohistochemistry; Male; Neoplasms, Hormone-Dependent; Prostate; Prostatic Neoplasms; Rats; Rats, Wistar; Treatment Outcome; Tretinoin

Several reports have characterized the retinal degeneration observed in the Mitf(vit) mutant mouse. Despite these reports, the factor(s) that may cause or modulate the degeneration still are not well defined; however, it is known that the photoreceptors of Mitf(vit) mice die through an apoptotic mechanism. We reported previously that retinoid metabolism in the RPE of Mitf(vit)++ mice is perturbed. Retinoids regulate genes via the RAR and RXR nuclear receptor pathway that are involved in numerous cellular responses including apoptosis. It is possible that retinoic acid (RA) modulates the retinal degeneration observed in the Mitf(vit) mice. The purpose of this study was to evaluate the levels of RA in whole eyes, as well as its distribution between neural retina and RPE, of the Mitf(vit) mutant mouse model. An additional purpose was to examine the expression of the RA generating enzyme, retinaldehyde dehydrogenase (AHD2), in the eyes of mutant and control mice.. The distribution of AHD2 in eyes of pre- and postnatal Mitf(vit) and C57BL/6 wild-type mice was determined immunohistochemically. Quantitative and qualitative analyses of RA were performed using reversed-phase high performance liquid chromatography (HPLC).. The distribution of AHD2 in ocular tissues was similar between pre- and postnatal Mitf(vit) and C57BL/6 control mice. At postnatal week 10, however, a marked increase in AHD2 immunoreactivity was noted in the central dorsal neural retina of Mitf(vit) mice. No differences in the level of total RA in whole eyes were noted between Mitf(vit) and control mice at early postnatal ages. By 10 weeks of age there was a significant elevation of RA that was localized to the neural retina.. In this study, we show a high level of AHD2 and RA in the neural retina of Mitf(vit) mice relative to control mice. It is possible that this elevation of RAs contributes to the retinal degeneration observed in Mitf(vit) mice either by inducing apoptosis or by enhancing the effect of some other factor(s) involved in the apoptotic pathway.

Topics: Aldehyde Oxidoreductases; Animals; Animals, Newborn; Chromatography, High Pressure Liquid; Disease Models, Animal; Eye; Immunohistochemistry; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Pigment Epithelium of Eye; Retina; Retinal Degeneration; Retinal Dehydrogenase; Time Factors; Tretinoin

The purpose of this assay was to study the hindfoot patho-dynamic in clubfoot-like deformity during fetal development. Experimental induction of clubfoot-like deformity in rat fetuses was produced by maternal administration of retinoic acid (120 mg/kg body weight) as a single intragastric dose on day 10 of pregnancy. Hindlimbs from fetuses at 17, 19, and 21 days were removed, and serial sections in three planes were made. Experimental and control hindlimbs were studied. There was clubfoot-like deformity in 86.5% of the experimental fetuses and none in the controls. Other associated malformations found were craniofacial (96.3%), neural tube (75.7%), and club-hand (40.3%) defects. Persistence of the embryonic position of the talus and tibia in fetuses with severe clubfoot-like deformity was observed. No overlapping between talus and calcaneus was seen. An equinus position, medialization of anterior segment, and lateralization and inward torsion of the posterior body of the calcaneous were observed. Results of this study showed that there are rotational anomalies in the hindfoot and full hindlimb from the beginning of the fetal period, and these anomalies increase during development. This simple model may allow us to gain better knowledge in congenital clubfoot deformity.

Topics: Animals; Clubfoot; Disease Models, Animal; Embryonic and Fetal Development; Female; Fetal Diseases; Foot; Pregnancy; Rats; Reference Values; Tretinoin

Retinoids constitute a very promising class of agents for the chemoprevention or treatment of breast cancer. These retinoids exert their biological activity through two distinct classes of retinoic acid (RA) receptors (R), the RAR isotypes (alpha, beta, and gamma) and the three RXR isotypes (alpha, beta, and gamma) and their numerous isoforms which bind as RXR/RAR heterodimers to the polymorphic cis-acting response elements of RA target genes. With respect to these numerous receptor sub-types, the retinoid-induced effects at the biological level include marked modifications with respect to both cell proliferation and cell death (apoptosis), and also in the induction of differentiation processes. The present study aims to characterize the effect which four retinoids (TTNPB, 9-cis-RA, LGD 1069, 4-HPR) with distinct RAR/RXR binding properties induced on various in vitro and in vivo mouse and human breast cancer models. The experiments with the retinoids were carried out in comparison with the anti-estrogen tamoxifen and the anti-progestagen RU-486 compounds. The results show that the 6 compounds under study were markedly more efficient in terms of growth inhibition in the human T-47D cell line when maintained under anchorage-independent culture conditions than when maintained under anchorage-dependent ones. While RU-486 exhibited a weak statistically significant (p < 0.05) influence on the growth of the T-47D stem cells, tamoxifen had a marked inhibitory influence on the growth of these cells. Of the four retinoids, 4-HPR was the least effective since the lowest doses tested (1 and 0.1 nM) exhibited no statistically (p > 0.05) significant influence on the growth of the stem cells. The most efficient retinoid was TTNPB. It was only at the highest dose (10 microM) that tamoxifen and RU-486 showed a weak inhibitory influence on the growth of the T-47D non-stem cells while all 4 retinoids exerted a significant inhibitory influence on the growth of these non-stem cells, with 4-HPR being the most efficient (P < 0.001) at the highest dose, but ineffective (P > 0.05) at the lowest. Tamoxifen and TTNPB were tested in vivo on hormone-sensitive (HS) and hormone-insensitive (HI) strains of the MXT murine mammary carcinoma. While TTNPB appeared to be equally efficient in terms of growth inhibition in both MXT-HS and MXT-HI models, tamoxifen had only a marginal inhibitory influence on the growth of the MXT-HI strain but did inhibit growth in the case of the MXT-HS one. TT

Topics: Alitretinoin; Animals; Anticarcinogenic Agents; Apoptosis; Benzoates; Bexarotene; Breast Neoplasms; Cell Division; Disease Models, Animal; Female; Fenretinide; Hormone Antagonists; Humans; Mammary Neoplasms, Animal; Mice; Mice, Inbred C57BL; Mifepristone; Retinoids; Tamoxifen; Tetrahydronaphthalenes; Tretinoin; Tumor Cells, Cultured

To determine the antiproliferative activity in intravitreous retinoic acid (RA) dispersed in 1% sodium hyaluronate (HA).. Six groups of pigmented rabbits underwent gas-compression vitrectomy. Four days later, gas/HA or gas/balanced salt solution (BSS) exchange (1.0 m1) was performed in all rabbits. Groups A (n = 10) and B (n = 5) received intravitreous RA dissolved in 0.01 m1 of ethanol and dispersed in 1% HA (10 and 15 micrograms RA/m1, respectively). Group C (n = 10) received intravitreous RA dissolved in ethanol and dispersed in BSS (10 micrograms RA/m1). Groups D (n = 5) and F (n = 4) received 1 m1 of HA with ethanol; group E (n = 5) received 1 m1 of HA without ethanol. All groups except group F also received homologous fibroblasts and autologous, platelet-rich plasma intravitreously. The eyes were examined ophthalmoscopically for 1 month. Proliferative vitreoretinopathy (PVR) findings were graded according to the classification of Fastenberg et al. all group F eyes also were examined by light and electron microscopy.. RA in HA lessened PVR progression within 1 month when compared with HA injection controls and within 2 weeks when compared with the RA in BSS treatment group (both, p < 0.05). NO specific change attributable to ethanol was observed histopathologically.. RA dissolved in ethanol and dispersed in HA could be useful to treat PVR when silicone oil is unnecessary.

Topics: Animals; Blood Transfusion; Cell Division; Disease Models, Animal; Ethanol; Female; Fibroblasts; Hyaluronic Acid; Male; Osmolar Concentration; Plasma; Platelet Transfusion; Rabbits; Sodium Chloride; Solutions; Tretinoin; Vitreoretinopathy, Proliferative

Complete transposition of the great arteries (TGA) is inducible by treatment with all-trans retinoic acid in the ICR mouse. In this model, hypoplasia and dysplasia of the proximal outflow tract cushion tissue lead to non-spiral septation. In order to evaluate the effect of retinoic acid on the extracellular matrix of the cardiac outflow tract, we examined the distribution of collagen type I and hyaluronic acid, immunohistochemically, on days 8-9 of gestation. In controls, collagen type I fibrils ran mainly in a radial direction, extending towards the endocardium in the cardiac jelly of the proximal outflow tract. Also, a pair of longitudinal fiber bundles were formed stretching to the distal outflow tract. As for hyaluronic acid, intense staining was observed in the submyocardial and intermyocardial space of the outer curvature of the heart. On the other hand, in retinoic acid-treated embryos, the submyocardial radial fibrils or longitudinal fiber bundles of collagen type I were diminished, and irregular and dense deposits of collagen type I were observed along the endocardium. Furthermore, hyaluronic acid showed a loss of differential localization between the outer and inner curvature. Instead, irregular and intense staining was observed uniformly along the outflow myocardium. Thus, retinoic acid appeared to have perturbed the differentiation in the proximal outflow tract causing an altered organization of multiple extracellular matrix molecules, including collagen type I and hyaluronic acid, which led to an abnormal molecular network of the cardiac jelly in the cardiac outflow tract, abnormal septation and, further, to TGA or TGA-type anomalies.

Topics: Animals; Collagen; Disease Models, Animal; Female; Heart; Hyaluronic Acid; Immunohistochemistry; Mice; Mice, Inbred ICR; Morphogenesis; Myocardium; Pregnancy; Transposition of Great Vessels; Tretinoin

The skin of the Mexican hairless dog is covered with comedones, and this animal therefore provides a potentially useful model to assess the comedolytic activity of topical anti-acne drugs. We treated an animal with three different formulations of tretinoin for a 14-week period, and all produced a similar clinical response. There was a striking reduction in the number of comedones, and the skin became lighter and more uniform in colour. Histological changes were similar to those reported in humans treated with tretinoin, but a novel finding was incomplete neogenesis of hair follicles. We suggest that the Mexican hairless dog may be a useful model for screening novel molecules for retinoid activity.

Topics: Acne Vulgaris; Animals; Chemistry, Pharmaceutical; Disease Models, Animal; Dogs; Drug Evaluation, Preclinical; Female; Hair Follicle; Keratolytic Agents; Skin Pigmentation; Tretinoin

The precise pathologic processes of comedo formation in acne are not well understood. Retention hyperkeratosis may play an important role. To evaluate the effects of three topical comedolytics, 20% azelaic acid, 0.1% tretinoin and 5% benzoyl peroxide, on the retention hyperkeratosis of experimentally induced comedones (EIC), an ultrastructural study was done. After formation of EIC with 50% oleic acid in paraffin oil on the external ears of rabbits, each comedolytic was applied for 4 weeks. Biopsies were taken every week and, using a Hitachi H-600 transmission electron microscope, morphologic observations were done in the upper portion of the follicular epithelium. In EIC, after application of each comedolytic, the markedly thinned horny layer was loosely adhered by extremely few desmosomes and desmosomal bodies. The number and size of tonofilaments and keratohyaline granules decreased, but the number of variable sized Odland bodies increased in the upper epidermis. These findings appeared 1 week after application of either azelaic acid or benzoyl peroxide, and 3 weeks after application of tretinoin. For the first 2 weeks of tretinoin application, EIC showed rather compact hyperkeratosis with more desmosomes and desmosomal bodies than before. Azelaic acid tretinoin and benzoyl peroxide increased the number of Odland bodies, and the horny cells became less adhesive. This lysis of retention hyperkeratosis resulted in comedolysis. During 4 weeks of treatment with these three comedolytics, only tretinoin normalized the keratinization process.

Topics: Acne Vulgaris; Animals; Benzoyl Peroxide; Dermatologic Agents; Dicarboxylic Acids; Disease Models, Animal; Epithelial Cells; Epithelium; Evaluation Studies as Topic; Keratolytic Agents; Keratosis; Rabbits; Tretinoin

Vitamin A and its derivatives (retinoids) have been known to cause premature epiphyseal closure in humans as an unwanted side effect of chronic treatment. The purpose of the present study was to determine if guinea pigs could serve as an animal model of retinoid-induced epiphyseal plate closure, and to utilize this model to study the mechanism. Weanling male Hartley guinea pigs were treated ip via osmotic pump for up to 14 days with vehicle or 0.50 to 5.5 mg/kg/day of the retinoic acid receptor (RAR)-selective agonist AGN 190121. Histopathological examination of the proximal tibia of AGN 190121-treated guinea pigs revealed a dose-dependent disruption of the epiphyseal plate. The natural retinoids all-trans-retinoic acid and 13-cis-retinoic acid also induced epiphyseal plate closure in guinea pigs when administered by ip injection for 10 days. Prominent histological features of retinoid-induced epiphyseal closure included the loss of basophilic staining in the extracellular matrix of epiphyseal plate chondrocytes and the invasion of the epiphyseal plate by osteoclasts. To determine if the epiphyseal closure detected histologically was reversible, guinea pigs were treated for 6 days with the RAR-selective agonist (E)-4[2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)propen- 1-y1]benzoic acid (TTNPB) or vehicle, and groups of guinea pigs were euthanized on Day 7 or 57. TTNPB but not vehicle treatment caused histological evidence of epiphyseal closure at both time points, and significant bone elongation between Day 7 and Day 57 was detected only in vehicle-treated animals. Epiphyseal closure and other toxic effects of TTNPB were blocked by cotreatment of guinea pigs with a fivefold molar excess of AGN 193109, an RAR antagonist. Taken together, these data demonstrate the utility of the guinea pig as an animal model of retinoid-induced epiphyseal closure and suggest that RAR activation is necessary and sufficient for this activity.

Topics: Animals; Benzoates; Disease Models, Animal; Growth Plate; Guinea Pigs; Isotretinoin; Male; Receptors, Retinoic Acid; Tretinoin

An animal model of osteoporosis induced by retinoic acid was successfully established in 3-month-old male Wistar rats. The animals were given the drug 70 mg.kg-1.d-1 for 14 d intragastrically and sacrificed on day 29. The proximal tibia and middle tibia of the rats were processed undecalcifiedly for quantitative bone histomorphometry. Compared with the control rats, the cancellous and compact bone volume of the model rats were reduced markedly. The bone tissue microstructure showed some obvious pathological changes that the trabecular number were decreased, the separation of trabecular and medulla ossium cavity became large, the thickness of trabecular and cortex of bone were decreased. The mechanism of bone loss in the model rats was that the osteoclast was activated by retinoic acid which promoted bone resorption. Other changes in the model rats were also observed such as: the body weight, and the weights of seminal vesicle and prostate were decreased, the adrenal glands and spleen showed hyperplasia and hypertrophy. No change of the blood concentration of calcium, phosphorus, alkaline phosphatase, alanine transaminase, estradiol and testosterone in the model rats was observed.

Topics: Animals; Bone Resorption; Disease Models, Animal; Male; Osteoporosis; Rats; Rats, Wistar; Tretinoin

To obtain insight into the hemodynamics of abnormal cardiac development, a chick embryo model was recently developed in which a spectrum of double outlet right ventricle was induced with all-trans-retinoic acid. In Hamburger and Hamilton (HH) stage 34 white Leghorn chick embryos, we simultaneously measured dorsal aortic flow velocities with a 20 MHz pulsed Doppler velocity meter and vitelline artery blood pressures with a servonull system. These measurements were performed in embryos treated at HH stage 15 with 1 microgram of all-trans-retinoic acid (n = 47), or with the solvent DMSO (n = 15), and in control embryos (n = 21). After the wave form recordings were collected, all embryos were examined histologically. Embryos treated with all-trans-retinoic acid showed in 15 cases hearts with a rightward positioned aorta with an additional subaortic ventricular septal defect and 32 cases without septation abnormalities of the heart. The hemodynamic data were correlated with the morphology. Statistical comparison was performed between control and experimental values. There was no significant discrepancy in hemodynamics of sham-operated and control embryos. Heart rate, peak systolic and mean velocities, peak systolic and mean blood flows, and peak acceleration and stroke volume were reduced in embryos treated with all-trans-retinoic acid (p < 0.01). Furthermore, in the presence of a subaortic ventricular septal defect the diameter of the dorsal aorta was reduced. Pressure readings were not statistically significant. Our findings suggest that the hemodynamic changes are the result of a decrease in cardiac contraction force.

Topics: Animals; Aorta; Blood Flow Velocity; Body Weight; Chick Embryo; Disease Models, Animal; Heart; Heart Defects, Congenital; Heart Septal Defects, Ventricular; Hemodynamics; Humans; Organ Size; Tretinoin; Vascular Resistance

Syndactyly is a common congenital hand anomaly that may occur after exposure to teratogens. We have developed an in vitro model of syndactyly to investigate the molecular mechanisms underlying this malformation of digit development. Retinoic acid, which regulates pattern formation in vertebrate limb development and is associated with teratogenic malformations, was used in the development of this syndactyly model system. Pregnant Swiss-Webster mice were given retinoic acid by oral gavage on days 10 and 11 of embryonic development (E10 and E11, respectively). The mice were sacrificed on gestational days 13 and 17 (E13, E17) and immediately postnatally (PN). The fetuses were removed and the forelimbs dissected under the operating microscope. The E13 limbs were cultured for 4 days (E13+4) in an organ culture system using a serumless, chemically defined medium. The E17, PN, and E13+4 forelimbs were critically examined for malformations of digit separation and digit development. Retinoic acid-induced fetal mouse forelimb syndactyly was observed in all the groups; 81 percent of E17 limbs, 75 percent of PN limbs, and 77 percent of E13+4 limbs had syndactyly. The morphology of the digital malformations was similar in the E17, PN, and E13+4 limbs. This in vitro model permits further studies to characterize the molecular changes that occur during the development of a congenital hand anomaly.

Topics: Animals; Disease Models, Animal; Female; Forelimb; Mice; Organ Culture Techniques; Pregnancy; Syndactyly; Teratogens; Tretinoin

We report on our experience in the experimental induction of Neural Tube Defects (NTD) in the foetal rat by maternal administration of retinoic acid. The teratogen diluted in olive oil was administered in a single intragastric dose (125 mg/kg body weight) to pregnant rats (n = 31) on the 10th day of gestation. Pure olive oil was given to control rats (n = 9). The foetuses were recovered by caesarian section on the 20th day and prepared for morphological investigation. We have studied 201 experimental and 82 control animals. There were NTD in 36.3% of experimental foetuses and none in the control ones. Sacral dysraphism was the most frequent defect but we also observed Arnold Chiari malformations and crowding of the bony limits by an enlarged neural axis. Other associated malformations found were: craneofacial (78.1%), caudal (80%), anorectal (31.4%), and limb defects (89.5%). This simple and inexpensive model may allow us to gain a better knowledge of the biology in the foetus with NTD.

Topics: Abnormalities, Drug-Induced; Animals; Disease Models, Animal; Female; Fetus; Neural Tube Defects; Pregnancy; Rats; Rats, Wistar; Tretinoin

The authors evaluated the effect of retinoic acid (RA) in silicone oil (SiO) and in silicone-fluorosilicone (SiFO) copolymer oil in a new rabbit model of proliferative vitreoretinopathy (PVR).. To create the PVR model, three groups of rabbits were administered vitreous injections of approximately 100,000 homologous fibroblasts, 75,000 platelet-rich plasma (PRP), and fibroblasts + PRP, respectively. These rabbits were followed up ophthalmoscopically and histopathologically for as long as 2 months. Five additional groups of rabbits underwent gas-compression vitrectomy in one eye. Four days later, group 1 was administered intravitreous RA in SiFO (9 micrograms/ml) with approximately 150,000 fibroblasts and 70,000 PRP. Group 3 was administered the same amount of fibroblasts and PRP as group 1 with RA in SiO (9 micrograms/ml). Groups 2, 4, and 5 were administered the same amount of fibroblasts and PRP as groups 1 and 3 with 1 ml of SiFO, SiO, or balanced salt solution only, respectively. To evaluate RA toxicity, RA was injected in SiO (15 and 20 micrograms/ml) and RA in SiFO (10 micrograms/ml).. All eyes that were administered fibroblasts or PRP developed vitreous membranes, but those with PRP alone did not develop proliferative changes or retinal detachment; fibroblasts alone produced proliferative changes and retinal detachment after 2 to 3 weeks; fibroblasts + PRP produced similar changes within 3 days of injection. Retinoic acid (15 micrograms/ml) in SiO and RA (10 micrograms/ml) in SiFO was well tolerated. Retinal atrophic changes were found in eyes with 20 micrograms/ml RA in SiO. The retinal detachment rate was lower (P < 0.05) in the eyes that were administered fibroblasts + PRP and RA than in the controls. Significant differences were found in the degrees of PVR among the groups.. RA could be useful in PVR treated with SiO or for eyes treated intraoperatively with heavier-than-water SiFO when it is used as a short-term retinal tamponade.

Topics: Animals; Blood Platelets; Disease Models, Animal; Drug Carriers; Fibroblasts; Injections; Rabbits; Random Allocation; Retina; Retinal Detachment; Silicone Oils; Tretinoin; Vitreoretinopathy, Proliferative; Vitreous Body

A series of 16 experiments, using a total of 2,000 BD6 rats, was designed in order to assess the ability of 8 individual agents or their combinations to modulate the liver and oesophageal carcinogenesis induced by multiple doses of diethylnitrosamine (DEN). Of the antioxidants tested, sodium selenite, ascorbic acid, and butylated hydroxytoluene generally exhibited protective effects on both types of tumors. In contrast, retinoic acid behaved as a promoter of DEN hepatocarcinogenesis, but this effect could be eliminated by its combination with either selenite or butylated hydroxytoluene. Caffeine and theophylline, when individually assayed, were devoid of significant protective effects, and the latter methylxanthine stimulated oesophageal tumorigenesis when administered after exposure to the carcinogen. Caffeine tended to decrease the multiplicity of liver tumors and potentiated the inhibitory effect of selenite in the liver. Irrespective of combination with caffeine, treatment with phenobarbital before each DEN injection tended to reduce the multiplicity of both liver and oesophageal tumors. On the other hand, the metabolic inhibitor diethyldithiocarbamate, given after each DEN injection, dramatically enhanced the incidence and multiplicity of oesophageal tumors. Thus, on the whole, modulation of DEN carcinogenesis varied depending on test agents, their combinations, dosages, treatment schedules, and target organ.

Topics: Animals; Antineoplastic Agents; Antioxidants; Ascorbic Acid; Caffeine; Diethylnitrosamine; Disease Models, Animal; Esophageal Neoplasms; Female; Liver Neoplasms, Experimental; Neoplasms, Experimental; Phenobarbital; Rats; Rats, Inbred Strains; Survival; Theophylline; Tretinoin

In an earlier study we showed that tretinoin could prevent corticosteroid-induced skin atrophy in hairless mice. In this study, we examined the histochemical, biochemical, and immunochemical changes that accompanied the atrophy and its prevention. Mice were treated dorsally for 3 weeks in the morning and afternoon (AM:PM) as follows: 1) vehicle:vehicle, 2) steroid:vehicle, 3) steroid:tretinoin. Tretinoin concentration was 0.05% in an ethanol:propylene glycol vehicle. The steroid was clobetasol propionate (0.05%). The normally sparse dermal glycosaminoglycans were further reduced by steroid:vehicle treatment and increased to greater than vehicle:vehicle amounts by steroid:retinoid. Mast cells were similarly affected. Biochemical quantification of glycosaminoglycans confirmed the histochemical findings. Collagen, non-collagenous protein, and total protein content were reduced by the steroid. The latter two were returned to more normal levels by tretinoin whereas with collagen there was only a trend toward normal levels. Fibronectin, which was increased by the steroid:vehicle treatment, was reduced to more normal levels by steroid:tretinoin. We conclude that tretinoin has the ability to prevent the major steroid-induced biomechanical changes in hairless mouse dermal connective tissue that contribute to atrophy.

Topics: Adrenal Cortex Hormones; Animals; Atrophy; Clobetasol; Collagen; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Fibronectins; Glycosaminoglycans; Histocytochemistry; Image Processing, Computer-Assisted; Immunohistochemistry; Iron; Mast Cells; Mice; Mice, Hairless; Retinoids; Skin; Tolonium Chloride; Tretinoin

Evaluation of 13-cis-12-substituted analogues of retinoic acid in a series of dermatologic screens has revealed that structural modifications can lead to selectivity and specificity. An analogue, 11-cis,13-cis-12-hydroxymethylretinoic acid, delta-lactone, has been found to have good activity and to be devoid of topical and systemic toxicity.

Topics: Administration, Topical; Animals; Cricetinae; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Guinea Pigs; Hypervitaminosis A; Male; Mesocricetus; Mice; Mice, Hairless; Rabbits; Skin; Skin Diseases; Structure-Activity Relationship; Tretinoin

We describe an animal model to induce the histogenesis of squamous metaplasia of the cervical columnar epithelium, a condition usually preceding cervical neoplasia. This model is based on dietary retinoid depletion in female mice. Control sibling mice fed the same diet but with all-trans-retinoic acid (at 3 micrograms/g diet) showed the normal endocervical epithelial and glandular columnar morphology, typical of a simple epithelium without subcolumnar reserve cells. The stratified squamous ectocervical epithelium of these mice fed all-trans retinoic acid showed intense immunohistochemical staining in basal and suprabasal cells with mono-specific antibodies against keratins K5, K14, K6, K13, and, suprabasally, with antibodies specific for K1 and K10. At the squamocolumnar junction, the adjacent columnar epithelium (termed "suprajunctional") did not show staining for K5, K14, K6, K13, K1, and K10 but specifically stained for keratin K8, typical of simple epithelia and absent from the adjacent ectocervical squamous stratified lining (termed "subjunctional"), in striking contrast. Sections of the squamocolumnar junction from mice kept on the vitamin A-deficient diet for 10 weeks showed suprajunctional isolated patches of reserve cells, proximal and distal to the junction. These cells were detected prior to any symptoms of vitamin A deficiency, such as loss of body weight or respiratory discomfort. The subcolumnar reserve cells induced by vitamin A deficiency displayed positive staining for K5 and K14. As deficiency became severe, the reserve cells occupied the entirety of the suprajunctional basement membrane. This epithelium eventually became stratified and squamous metaplastic, the squamocolumnar junction was no longer discernible, and the entire endocervical epithelium and the endometrial glands lost K8 positivity, while acquiring K5, K14, K6, K13, K1, and K10 keratins typical of the ectocervix under normal conditions of vitamin A nutriture. Vitamin A deficiency also altered keratin expression and localization in squamous subjunctional epithelium. In situ hybridization studies for K1 and K5 mRNA showed their major site of expression at the basal (K5) and immediately suprabasal (K1) cell layers. The localization of both K5 and K1 proteins in these same cell layers, and above, is consistent with transcriptional regulation of these keratins. Early vitamin A deficiency caused the appearance of single subcolumnar reserve cells expressing K5 mRNA. After these ce

Topics: Animals; Carcinoma, Squamous Cell; Cervix Uteri; Diet; Disease Models, Animal; Epithelium; Female; Immunohistochemistry; In Situ Hybridization; Keratins; Metaplasia; Mice; Mice, Inbred BALB C; Mice, Nude; Phenotype; Precancerous Conditions; Retinoids; RNA, Messenger; Tretinoin; Uterine Cervical Neoplasms; Vitamin A Deficiency

Induction of differentiation as a treatment modality for nonseminomatous germ cell tumors (NSGCTs) may promote the development of residual mature teratoma (RMT), which is usually associated with primary tumors that are capable of spontaneous somatic differentiation. Therefore, we studied the combination of a cytotoxic drug and a differentiation-inducing agent in vivo in three murine teratocarcinoma models with different levels of spontaneous somatic differentiation: E86-379 (moderate differentiation); NF-1 (poor differentiation); and MH-15 (no differentiation). We used retinoic acid (RA) as differentiation-inducing agent and cisdiaminodichloroplatinum (CDDP) as cytotoxic drug, plus a combination of both. In four separate experiments, the combination of RA and CDDP gave a significant further reduction of tumor size as compared with treatment with either RA or CDDP alone. Morphologically intact tumor after treatment with combined RA-CDDP contained a smaller proportion of undifferentiated tissue (embryonal carcinoma) than after CDDP alone. However, somatic differentiation was not induced in the tumor model lacking spontaneous somatic differentiation. Toxicity was reflected in loss of body weight and death of some animals and closely paralleled the degree of tumor reduction in all experiments.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Differentiation; Cisplatin; Disease Models, Animal; Female; Mice; Mice, Inbred BALB C; Teratoma; Tretinoin

The aims were to obtain a controlled intravitreous release of retinoic acid (RA) by injecting drug loaded microspheres of biodegradable polymers and to study the potential use of this RA delivery system in a rabbit model of proliferative vitreoretinopathy (PVR).. The release of RA in vitro from 15 mg of 50-50 poly(DL-lactide-co-glycolide) (PLGA) in 1 ml of water at room temperature was measured with a spectrophotometer. In a rabbit model of PVR, 11 eyes were injected with 5 mg of microspheres containing 22 micrograms of RA/mg of PLGA, and seven control eyes were injected with microspheres of the same polymer that did not contain RA. In a third group, six rabbits were injected with 5 mg (n = 3) and 10 mg (n = 3) of microspheres containing RA.. The initial concentration of RA was 20.8 micrograms/mg of PLGA. The release curve showed a fairly constant daily release of 7 micrograms/d for about 30 days. At 40 days, the release rate decreased to about 6 micrograms/d. After 40 days, 82.8% of the RA was released. Four of 11 treated rabbits (36%) and 7/7 (100%) controls showed tractional retinal detachment (TRD) (P < 0.01) after 2 months. Histopathologically, a mild, localized, foreign body reaction was observed.. The authors obtained a sustained release of RA from PLGA microspheres in vitro for 40 days. A single injection of RA-loaded microspheres in suspension in BSS was effective in reducing the incidence of TRD after 2 months in a rabbit model of PVR.

Topics: Animals; Biocompatible Materials; Biodegradation, Environmental; Delayed-Action Preparations; Disease Models, Animal; Drug Carriers; Eye Diseases; Female; Lactic Acid; Male; Microspheres; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Polymers; Rabbits; Retinal Detachment; Retinal Diseases; Tretinoin; Vitreous Body

To evaluate, in vitro, the solubility and stability of all-trans RA in silicone oil (SiO) and, in vivo, the stability and the antiproliferative effect of all-trans RA in SiO on an experimental model of PVR.. The solubility and stability of RA in SiO, in vitro and in vivo, were evaluated by HPLC. Rabbits underwent unilateral gas-compression vitrectomy and gas-SiO exchange. Rabbits received 10 micrograms (n = 17), 5 micrograms (n = 11), and 2 micrograms (n = 9) of all-trans RA in SiO, and SiO only (n = 12). All rabbits received an intravitreous injection of 150,000 fibroblasts.. RA is stable in SiO in vitro, but some isomerization from all-trans to 13-cis was observed under light exposure. In vivo, after 1 week, trace amounts of RA in SiO were observed in the controls and in the experimental animals, suggesting a steady state between the release of RA from the SiO and from the retina to the SiO. The rate of fractional retinal detachment was significantly lower in the animals that received 10 and 5 micrograms of RA than in the controls (P < 0.05). No statistical differences were found between the eyes treated with 10 and 5 micrograms of RA. Eyes that received 2 micrograms of RA showed no difference from the control group.. The in vivo data suggest that retinoic acid might be useful as an antiproliferative agent in human eyes.

Topics: Animals; Cell Division; Cells, Cultured; Chromatography, High Pressure Liquid; Disease Models, Animal; Drug Stability; Eye Diseases; Female; Fibroblasts; Male; Rabbits; Retinal Detachment; Retinal Diseases; Silicone Oils; Solubility; Tretinoin; Vitreous Body

A novel arotinoid, 4-((2-(p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl- 2-naphthyl)propenyl]phenoxy))ethyl))-morpholine, was tested in rats bearing established chemically induced mammary tumors. At a dose of 0.35 mmol/kg/day of 4-((2-(p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2- naphthyl)propenyl]phenoxy)ethyl))-morpholine, decreased tumor growth was seen after 2 weeks. By weeks 4 and 5, tumor burdens were decreased to 10-30% of initial values and 50-70% of the animals became free of palpable tumors. Stabilization of tumor size through 15 weeks of treatment was seen in rats given 0.23 mmol/kg/day of the arotinoid. The predominate adverse effects of this compound were dose-dependent weight loss during the first 1-3 weeks, attributed to poor palatability of the food admix as well as flaking of the skin and alopecia at later times. Bone toxicity, a characteristic side effect of retinoids in rodents, was rare with this arotinoid, mainly confined to young rats treated for more than 12 weeks with high doses. In a comparative study, neither all-trans-retinoic acid nor 13-cis-retinoic acid had significant antitumor effects at doses that were tolerated by the animals. When all-trans-retinoic acid was administered at 0.08 mmol/kg/day, tumor reduction was seen during weeks 4-6, but treatment was terminated after week 6 due to severe skeletal toxicity and general deterioration in all the animals. Such marked toxicity was not evident with the arotinoid at doses having high antitumor activity. The high efficacy and relatively low toxicity of 4-((2-(p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2- naphthyl)propenyl]phenoxy)ethyl))-morpholine suggest that it may be a promising new anticancer agent.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Antineoplastic Agents; Disease Models, Animal; Eating; Female; Mammary Neoplasms, Experimental; Morpholines; Rats; Rats, Sprague-Dawley; Retinoids; Tretinoin

Retinoic acid (RA) is an inducer of epidermal proliferation by a mechanism of action which is not fully known. We examined the proliferative response of hairless mouse epidermis to a single topical application of different doses of RA (0.1-1000 nmol). The mitotic rate was assessed using the stathmokinetic method, and change in epidermal cell numbers were scored per microscopic vision field in tissue sections. Cell cycle parameters were measured by bivariate bromodeoxyuridine/DNA flow cytometry on isolated epidermal basal cells after pulse labelling up to 10 days after RA treatment. The results showed a dose-dependent increase in mitotic activity with a maximum at 3 days after RA application, and a dose-dependent hyperplasia with a maximum at 4 days after RA application. Cell-cycle analysis showed an immediate proliferative response after RA application similar to that following various skin irritants. Although differences in the G2 phase transit were seen, this indicates a similar mechanism of action of RA-induced epidermal proliferation and that associated with epidermal regeneration in general.

Topics: Animals; Bromodeoxyuridine; Cell Division; Disease Models, Animal; DNA; Epidermal Cells; Epidermis; Flow Cytometry; Hyperplasia; Kinetics; Male; Mice; Mice, Hairless; Mice, Mutant Strains; Mitotic Index; Regeneration; Tretinoin

Among the findings associated with the human Retinoic Acid Embryopathy are hindbrain defects including the Arnold-Chiari malformation. The human Arnold-Chiari malformation (ACM) is a malformation complex where the cardinal feature is herniation of the caudal hindbrain into the vertebral column; it is frequently accompanied by lumbosacral myelorachischisis and hydrocephalus. Mice exposed to all-trans-retinoic acid or etretinate on day 8.25 of pregnancy, produce offspring with hindbrain herniation and caudal lumbosacral myelorachischisis in addition to a variety of other craniofacial and caudal malformations. Several experimental animals were observed to lack the caudal myelorachischisis proving that this lesion is not required to generate hindbrain herniation. We provide evidence that the cranial malformations, including hindbrain herniation, result from primary damage to the neural crest and the rhombencephalon. The vulnerability of these sites appears to be correlated with the presence of normal physiological cell death. While these experimental animals differ in many respects from the typical human Arnold-Chiari malformation, they may provide some insight into the pathogenesis of the latter.

Topics: Abnormalities, Drug-Induced; Animals; Disease Models, Animal; Ear; Exophthalmos; Female; Humans; Isotretinoin; Male; Mandible; Mice; Mice, Inbred C57BL; Neural Crest; Pregnancy; Rhombencephalon; Tretinoin

Dietary calcium glucarate (CGT) increased the activity of non-toxic levels of dietary isotretinoin against pre-established tumors in the chemically-induced rat mammary tumour model. In the range of 1.0-1.5 mmol/kg diet, isotretinoin enhanced tumour growth by 20% over a 4 week course of treatment. Tumour growth inhibition not exceeding 15% was observed only at dosages as high as 2.0 mmol/kg, i.e. in the cumulative toxicity range. Growth inhibition by 64 mmol/kg diet of CGT alone was marginal, varying from zero to 8%. In contrast, the combination of 1.0 mmol/kg of isotretinoin and 64 mmol/kg of CGT caused a reversible inhibition of tumour growth, culminating in a net decrease in tumour volume of 20%. This study documents the marginal enhancement of tumour growth by high sub-optimal concentrations of isotretinoin alone, and describes conditions for inhibition of tumour growth by sub-optimal concentrations of the natural retinoid. Related in vitro studies on retinoid sensitive and insensitive cell lines suggest that the anticancer activity of the combination is dependent on sensitivity of the cells to retinoids.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Division; Diet; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Resistance; Drug Synergism; Female; Fenretinide; Glucaric Acid; Isotretinoin; Mammary Neoplasms, Experimental; Rats; Rats, Inbred Strains; Tretinoin

The effects of all-trans-retinoic acid (all-trans-RA) on benzo(a)pyrene [B(a)P]-induced malignant sarcomas in Sprague-Dawley female rats were evaluated. Ninety-eight days after B(a)P administration, all-trans-RA was daily injected to animals with or without clinically palpable tumors. The growth of tumors was slowed down compared with controls. Magnetic resonance imaging analyses showed that all-trans-RA-treated rat tumors presented early necrotic areas. Animal survival was slightly increased. Anti-phosphatidylinositol autoantibody levels which were significantly higher in B(a)P-treated rat sera were not modified by all-trans-RA treatment.

Topics: Animals; Anticarcinogenic Agents; Autoantibodies; Benzo(a)pyrene; Cell Division; Disease Models, Animal; Female; Magnetic Resonance Imaging; Phosphatidylinositols; Rats; Rats, Sprague-Dawley; Sarcoma, Experimental; Thyroglobulin; Tretinoin

A number of agents have been shown to alter the latent state of herpes simplex virus in murine sensory ganglia. However, it seems that effective triggers of recrudescent disease must act not only to reactivate latent HSV infection, but also to create a favorable environment in the skin for viral replication. The possibility that alteration of the local Langerhans cell population is one way in which effective triggers of recrudescence may act has been investigated. Of the agents tested, which affect latent HSV, only DMSO significantly altered the numbers of ATPase-bearing Langerhans cells in the epidermis, maximally reducing their density by 83% in 48 h. Xylene and retinoic acid had no discernible effect on numbers of ATPase-staining cells over the 4 d tested. However, the extent to which agents reduced ATPase-staining cell numbers did not correlate with their ability to affect the antigen-presenting capacity of the cells in HSV-specific T-cell proliferative assays in vitro. Xylene and retinoic acid markedly reduced the accessory cell function of epidermal cell suspensions, whereas DMSO had no effect.

Topics: Adenosine Triphosphatases; Animals; Dimethyl Sulfoxide; Disease Models, Animal; Female; Herpes Simplex; Langerhans Cells; Lymphocyte Activation; Mice; Mice, Inbred Strains; Simplexvirus; T-Lymphocytes; Tretinoin; Xylenes

Dithranol-induced skin irritation and the modulatory effects of different pharmacological agents were studied using the mouse ear model. A single topical application of dithranol caused a dose-dependent skin irritation which resulted in delayed swelling of the mouse ear with two separate peak responses, 1-2 and 6-10 days after application. The irritation was most effectively and persistently inhibited by topical treatment with corticosteroids, the free radical scavenger DL-alpha-tocopherol (DLAT) and the serotonin antagonist metergoline. The effect of corticosteroids, however, was slightly diminished during the second peak irritation. The lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA), the dual lipoxygenase and cyclo-oxygenase inhibitor tolfenamic acid and the cyclo-oxygenase inhibitor indomethacin as well as trifluoperazine retained their inhibitory activity. Of these compounds, indomethacin was active only during the first irritation peak, NDGA during both peaks and trifluoperazine principally during the second peak. Retinoic acid did not inhibit the ear swelling. The results confirm and extend the observations that the formation of free radicals is essential for dithranol inflammation. The inflammation can also be suppressed by inhibiting the formation of arachidonic acid or its pro-inflammatory metabolites.

Topics: Administration, Topical; Adrenal Cortex Hormones; Animals; Anthralin; Anti-Inflammatory Agents, Non-Steroidal; Disease Models, Animal; Dose-Response Relationship, Drug; Ear; Edema; Female; Hyperplasia; Indomethacin; Inflammation; Masoprocol; Mice; ortho-Aminobenzoates; Skin Diseases; Time Factors; Tretinoin; Trifluoperazine

The histological and ultrastructural effects following 3 weeks' topical treatment with two agents (all-trans retinoic acid and a new synthetic retinoid-like substance, CD271) were evaluated on the epidermis and the epithelial wall of the pseudocomedones in rhino mouse skin. The comedolytic effects of these drugs were similar, and consisted of a reduction of the utricular diameter, with normalization of follicular units. Morphological examinations revealed a hyperplastic response with an increase in the number of cell layers of both epidermis and follicular epithelium, and modifications in keratinocyte differentiation. Ultrastructural changes in the epidermis and epithelial wall were observed mainly in the granular and horny layers, with increased desquamation, and a decrease in the cohesiveness of corneocytes. During the first week of treatment, some cutaneous toxic effects were noticed, but they normalized within two weeks. On the other hand, a fine granular material persisted in the intercellular spaces. It is confirmed that the skin of the rhino mouse is a good model for the evaluation of the comedolytic effects of drugs. Moreover, it reveals the specific effects of retinoids on epidermal differentiation. We have demonstrated that topically applied CD271 induces modifications similar to those obtained with all-trans retinoic acid. It is thus concluded that CD271 is a potentially effective anti-acne agent.

Topics: Adapalene; Administration, Cutaneous; Animals; Anti-Inflammatory Agents, Non-Steroidal; Disease Models, Animal; Epidermis; Female; Male; Mice; Mice, Hairless; Microscopy, Electron; Naphthalenes; Tretinoin

Treatment of C57Bl/6J mice with three successive doses of all-trans retinoic acid (28 mg kg-1 body weight) on 8 day, 6 h (8d,6h), 8d,12h, and 8d,18h of gestation resulted in a high incidence (79%, 31/39 fetuses) of spina bifida with myeloschisis (spina bifida aperta) in near term fetuses. Twelve hours following the last maternal dose (9d,6h), the caudal aspects of treated embryos, were abnormal, with eversion of the neural plate at the posterior neuropore, as compared to its normal concavity in comparably staged control specimens. This eversion persisted in affected embryos through the time that the posterior neuropore should normally close. The distribution of cell death in control and experimental embryos was determined using vital staining with Nile blue sulphate and with routine histological techniques. Twelve hours following the maternal dosing regimen, experimental embryos showed evidence of excessive cell death, predominantly in the mesenchyme associated with the primitive streak and in the endoderm of the tail gut, both of which are readily identifiable sites of physiological cell death at this stage of development. In addition, the presumptive trunk neural crest cells located in the dorsal midline, cranial to the posterior neuropore, exhibited a marked amount of cell death in the experimental embryos. We propose that the major factor in the generation of spina bifida in this model is excessive cell death in the tail gut and mesenchyme ventral to the neuroepithelium of the posterior neuropore.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cell Survival; Disease Models, Animal; Mesoderm; Mice; Mice, Inbred Strains; Microscopy, Electron, Scanning; Spina Bifida Occulta; Tretinoin

The effects of topical tretinoin on epithelial wound healing were studied using a porcine model. Eight animals were treated with 0.05% tretinoin cream daily for ten days prior to partial-thickness skin wounding. Daily tretinoin treatment was continued after wounding on two of eight animals. Treatment with topical tretinoin before wounding accelerated epithelial wound healing in partial-thickness wounds. Continued tretinoin treatment on the wounds themselves retarded reepithelialization. Biopsy specimens of wounds with continued tretinoin treatment revealed persistent inflammation and fibroplasia in the dermis. The healing epithelium itself displayed areas of spongiosis and intracytoplasmic pale eosinophilic periodic acid-Schiff-positive, diastase-resistant globules. These globules did not stain with alcian blue. These epidermal alterations may be a direct effect of tretinoin or may be secondary to the underlying inflammation. While the dermal inflammation associated with continued tretinoin treatment appears to retard reepithelialization, epithelial cell alterations may also play a role.

Topics: Administration, Topical; Animals; Biopsy; Disease Models, Animal; Epithelium; Staining and Labeling; Swine; Tretinoin; Wound Healing

The hairless mouse is proving to be a relevant model for the systematic study of photoaging. As in humans, with chronic ultraviolet radiation, these mice develop elastic fiber hyperplasia, followed by elastosis and ultrastructural degradation. Collagen is damaged and its metabolism is altered, while the normally low levels of proteoglycans and glycosaminoglycans are greatly increased. With this model we have described the effects on dermal connective tissue of UVB (290 to 320 nm), UVA (320 to 400 nm), and the combination of the two. We have also assessed the protective effects of sunscreens. We found that a significant amount of photodamage was repaired when ultraviolet radiation was stopped. Subepidermally in a former region of elastosis, a band of new normal dermis was laid down. Enhancement of the repair was achieved with topical all-trans-retinoic acid in a time- and dose-dependent manner. Retinoic acid was also found to induce angiogenesis in unirradiated mice.

Topics: Aging; Animals; Disease Models, Animal; Mice; Mice, Hairless; Skin; Skin Diseases; Sunscreening Agents; Tretinoin; Ultraviolet Rays

Acute exposure to 400 mg/kg 13-cis retinoic acid (13-cis RA, isotretinoin, Accutane) on the ninth day postfertilization in mice (a time that corresponds to the fourth week postfertilization in humans) results in malformations that characterize mandibulofacial dysostosis (MFD, Treacher Collins syndrome). Deficiencies in the infraorbital region and in the mandibular ramus and condyle, abnormalities of the secondary palate, and external ear malformations were observed. Light and scanning electron microscopic analyses of affected embryos illustrate that within 12 hours of maternal 13-cis RA treatment, markedly excessive (possibly premature) cell death occurs in regions where some of the cells are normally destined to undergo programmed cell death. Previous studies with retinoids have shown that they labilize lysosomal membranes and expand and strengthen regions of programmed cell death. Of particular interest for this study was cell death occurring in the dorsal (proximal) aspects of the maxillary and mandibular prominences of the first visceral arch, the second visceral arch, and the first visceral cleft, areas that correspond to the locations of the first and second arch ectodermal ("ganglionic") placodes and first closing membrane, respectively. The derivatives of this region are those that are severely affected in MFD. As described in previous reports from this laboratory, 13-cis RA is known to interfere with neural crest cells, resulting in major craniofacial malformations. However, the exposure times involved were earlier than those described herein. It is hypothesized that effects on the first and second arch ectodermal placodal cells at a time following the release from the neural folds of neural crest cells into the developing cranial region are of great significance in the pathogenesis of MFD. This is in contrast to the prevailing hypothesis that these malformations are the direct result of a primary interference with neural crest cells.

Topics: Animals; Cell Survival; Disease Models, Animal; Female; Isotretinoin; Mandibulofacial Dysostosis; Mice; Mice, Inbred C57BL; Tretinoin

The long-term (12 months) oral administration of the aromatic retinoid Ro 10-1670 (etretin) to dogs in relatively high doses of 5.0, 15.0 and 50.0/30.0 mg/kg/day was followed by acanthotic hyperplasia of the epidermis in the external auditory meatus and dose-dependent hypertrophy and/or hyperplasia of the canine ceruminous glands. These morphological changes were accompanied by a secretory stimulation on the ceruminous glands which was slight in the low-dose dogs but in the majority of the high-dose dogs reached a degree that was followed by secondary acute infectious inflammation. The alterations in the external auditory canal ceased almost immediately when treatment of dogs with the aromatic retinoid was stopped but recommenced when it was restarted.

Topics: Acitretin; Animals; Cerumen; Disease Models, Animal; Dog Diseases; Dogs; Ear Canal; Exocrine Glands; Otitis Externa; Tretinoin

We studied the effects of oral administration of the retinoid, 4-hydroxyphenyl retinamide (4-HPR), on group A streptococcal cell wall-induced polyarthritis in the rat, a model characterized initially by exudative inflammation of peripheral joints followed by chronic proliferative/erosive synovitis. Experimental arthritis was induced in female LEW/N rats by i.p. injection of streptococcal cell walls in saline (15 micrograms/g body weight). Depending upon the experiment, continuous daily oral administration of the retinoid was begun either 14 days prior to induction of the disease, at the time of cell wall administration and/or 11 days and 31 days after cell wall injection. Dosage was either 1 or 2 mmol 4-HPR/kg of chow. During the course of the disease, severity of clinical illness was assessed by determination of clinical severity index, by histological or radiologic examination, and by measurement of production in vitro of collagenase and prostaglandin E2 by excised synovial tissue. In rats fed the retinoid prior to cell wall injection, both the acute and the chronic responses were suppressed. In rats given the retinoid at the time of cell wall injection, the acute inflammatory response was only partially suppressed on the diet containing 2 mmol 4-HPR/kg chow, but the chronic disease was impressively inhibited in a dose dependent manner. Similarly, in animals with established disease, the drug was also effective; however, the more advanced the illness, the less effective the drug. Clinical observations were paralleled by the histological, radiographical and biochemical analyses. Treated animals showed far less synovial proliferation and joint destruction, and synovial tissues taken from these rats produced lesser amounts of collagenase and prostaglandin E2. No significant toxicity of the retinoid was noted. We conclude that oral administration of 4-HPR suppresses, in a dose and time dependent manner, both the acute and chronic stages of streptococcal cell wall-induced arthritis in rats without apparent significant toxicity. Our data suggest that studies of the effects of this retinoid on patients with chronic inflammatory synovitis are warranted.

Topics: Animals; Arthritis; Cell Wall; Dinoprostone; Disease Models, Animal; Female; Fenretinide; Granuloma; Liver Diseases; Microbial Collagenase; Prostaglandins E; Rats; Rats, Inbred Lew; Streptococcus pyogenes; Tretinoin

The intradermal injection of 140 micrograms of Propionibacterium acnes (CN 6134) into the ears of female Sprague-Dawley rats produced a chronic inflammation with formation of acneiform lesions. Inflammation was characterized by more than a doubling of ear thickness at 24 h and a peak of 3-4 times control levels at day 21. At 42 days post injection ears were still 3 times normal thickness. Histologically there was early polymorph accumulation giving way to macrophages and lymphocytes by day 7. Pilosebaceous follicles overlying the inflamed area lost their sebaceous glands and became hyperplastic cords of cells that grew down and encapsulated inflammatory loci. By day 9 many of these follicles had become secondary comedones. Three isolates of P. acnes from inflammatory acne lesions and 4 of 5 isolates from non-acne patients produced results similar to that of the strain CN 6134. In these cases the number of histologically evident secondary comedones was correlated with ear thickness. In contrast, samples of Streptococcus lactis, Escherichia coli B, and Staphylococcus epidermidis failed to produce this combination of chronic inflammation and high lesion count. Benzoyl peroxide, tetracycline, erythromycin, phenidone, naproxen, and cis and trans retinoic acid were inactive as inhibitors of P. acnes CN 6134-induced ear thickening. The corticosteroid fluocinolone acetonide produced dramatic suppression of inflammation, but upon cessation of treatment the ears returned to inflamed levels. The specificity for P. acnes, the formation of acneiform lesions, and the recalcitrance of the inflammation suggest our model is indeed relevant to acne.

Topics: Acne Vulgaris; Animals; Benzoyl Peroxide; Disease Models, Animal; Erythromycin; Female; Fluocinolone Acetonide; Inflammation; Injections, Intradermal; Naproxen; Propionibacterium acnes; Pyrazoles; Rats; Rats, Inbred Strains; Tetracycline; Tretinoin

Topics: Animals; Black or African American; Disease Models, Animal; Ear; Humans; Male; Rabbits; Salicylates; Salicylic Acid; Skin Diseases; Tretinoin

Topics: Animals; Carrier Proteins; Castration; Cells, Cultured; Concanavalin A; Disease Models, Animal; Horseradish Peroxidase; Humans; Hydrolases; Lysosomes; Male; Neoplasm Proteins; Prostatic Neoplasms; Rats; Receptors, Retinoic Acid; Tretinoin

Topics: Animals; Disease Models, Animal; Hyperlipoproteinemias; Lipoproteins, VLDL; Liver; Male; Rats; Tretinoin; Triglycerides

Highly invasive carcinomas of the urinary bladder were induced in male C57BL/6 X DBA/2 F1 (hereafter called B6D2F1) mice by gastric intubation of N-butyl-(4-hydroxybutyl)nitrosamine (OH-BBN) using a quantitative dosing schedule. Animals received either 5 or 10 mg OH-BBN per intubation, two times each week, for 9 weeks for a total dose of either 90 or 180 mg, and they were killed 6 months after the first carcinogen intubation. Seven days after the final intubation of OH-BBN, animals were fed either a placebo diet or diet supplemented with either 150 or 200 mg 13-cis-retinoic acid per kg of diet. A 41 and 43% incidence of urinary bladder cancer was observed in mice given the low and high dose of carcinogen, respectively, and fed a placebo diet. Sixty-seven % of the carcinomas induced in these animals invaded either into or through the urinary bladder wall. Varying degrees of transitional and either squamous or glandular or both squamous and glandular differentiation were observed in the carcinomas. Feeding of diet supplemented with 13-cis-retinoic acid reduced cancer incidence; the degree of reduction was proportional to the dose of retinoid administered. The highly invasive nature of the carcinomas induced by quantitative administration of OH-BBN in B6D2F1, mice provides a useful animal model of the highly invasive variant of human transitional cell urinary bladder cancer in which to study chemoprevention by retinoids as well as other compounds.

Topics: Animals; Butylhydroxybutylnitrosamine; Disease Models, Animal; Male; Mice; Microscopy, Electron; Neoplasms, Experimental; Nitrosamines; Tretinoin; Urinary Bladder Neoplasms

Topics: Animals; Cells, Cultured; Disease Models, Animal; Haplorhini; Male; Metaplasia; Microscopy, Electron; Neoplasms, Experimental; Prostate; Testosterone; Transplantation, Homologous; Tretinoin

Both retinoic acid and retinyl acetate, administered in high doses on days 13--15 of gestation, are capable of causing a 90 per cent incidence of cleft palate in Charles River rats. However, an attempt to develop as in vivo rabbit model system for the induction of clefts via hypervitaminosis A was unsuccessful. In the rat, the retinoic acid form of vitamin A is the more potent teratogen, inducing clefts at less than half the dose required to produce them with retinyl acetate. Histologic examination of fetal rat heads confirmed the biochemical evidence that retinoic acid is the more potent teratogen. Both forms of vitamin A prevented palatal shelf reorientation from occurring at the correct gestational age. The retinyl acetate treatment delayed the rotation for approximately 12 hours, the retinoic acid for at least 48 hours.

Topics: Animals; Cleft Palate; Disease Models, Animal; Diterpenes; Palate; Rabbits; Rats; Retinaldehyde; Retinyl Esters; Teratogens; Tretinoin; Vitamin A

Topics: Animals; Disease Models, Animal; Light; Membranes; Microscopy, Electron; Microscopy, Electron, Scanning; Phagocytosis; Photoreceptor Cells; Rats; Retinal Degeneration; Temperature; Tretinoin; Visual Fields; Vitamin A Deficiency

Daily treatment of guinea-pig ear skin with topical 0.5% retinoic acid in acetone produced erythematous scaly dermatitis. Histologic sections revealed bandlike thickening of the epidermis on days 2 to 4, psoriasiform acanthosis, papillomatosis and increased mitotic activity on days 5 to 6. Also seen were dilatation of the upper dermal blood vessels and a fibroblastic, histiocytic reaction in the dermis. Prostaglandin E, cyclic AMP, and cyclic GMP levels were increased in the treated skin and thymidine incorporation was enhanced. Cyclic AMP and GMP levels peaked on day 5 simultaneous with maximal epidermal hyperplasia, increased mitotic activity and dermal reaction. Tritiated thymidine uptake peaked on days 4 and 5, and prostaglandin E levels continued to increase up to day 6. Cyclic AMP phosphodiesterase activity of treated skin on day 5 did not appear to be significantly different from control.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Administration, Topical; Animals; Cell Division; Cyclic AMP; Cyclic GMP; Disease Models, Animal; Erythema; Guinea Pigs; Male; Models, Biological; Prostaglandins E; Psoriasis; Skin; Skin Physiological Phenomena; Thymidine; Tretinoin; Vitamin A