prostaglandin-d2 and Disease-Models--Animal

Itching, or pruritus, can be defined as an unpleasant sensation that evokes the desire to scratch. Pruritus is most commonly associated with a primary skin disorder such as atopic dermatitis (AD), psoriasis, etc., and can have a major impact on the quality of life of those patients. Itch-induced scratching can further damage the skin barrier, leading to a worsening of symptoms. For that reason, it is important to manage pruritus. Topical glucocorticoids are commonly the first-line therapy in the management of AD and psoriasis patients. We found that topical glucocorticoids induce pruritus in mice under certain conditions. Topical glucocorticoids may induce pruritus in a mouse model of allergic contact dermatitis via inhibition of prostaglandin (PG)D

Topics: Administration, Topical; Animals; Dermatitis, Atopic; Disease Models, Animal; Glucocorticoids; Humans; Mast Cells; Mice; Patient Education as Topic; Pharmacists; Professional Role; Prostaglandin D2; Pruritus; Psoriasis; Skin

Prostaglandins (PGs) are produced via cyclooxygenases, which are enzymes that play a major role in neuroinflammation. Epidemiological studies show that chronic treatment with low levels of cyclooxygenase inhibitors (nonsteroidal anti-inflammatory drugs (NSAIDs)) lowers the risk for Alzheimer's disease (AD) and Parkinson's disease (PD) by as much as 50%. Unfortunately, inhibiting cyclooxygenases with NSAIDs blocks the synthesis of downstream neuroprotective and neurotoxic PGs, thus producing adverse side effects. We focus on prostaglandin J2 (PGJ2) because it is highly neurotoxic compared to PGA1, D2, and E2. Unlike other PGs, PGJ2 and its metabolites have a cyclopentenone ring with reactive α,β-unsaturated carbonyl groups that form covalent Michael adducts with key cysteines in proteins and GSH. Cysteine-binding electrophiles such as PGJ2 are considered to play an important role in determining whether neurons will live or die. We discuss in vitro and in vivo studies showing that PGJ2 induces pathological processes relevant to neurodegenerative disorders such as AD and PD. Further, we discuss our work showing that increasing intracellular cAMP with the lipophilic peptide PACAP27 counteracts some of the PGJ2-induced detrimental effects. New therapeutic strategies that neutralize the effects of specific neurotoxic PGs downstream from cyclooxygenases could have a significant impact on the treatment of chronic neurodegenerative disorders with fewer adverse side effects.

Topics: Alzheimer Disease; Animals; Disease Models, Animal; Humans; Inflammation; Lipopolysaccharides; Neurodegenerative Diseases; Neurons; Parkinson Disease; Prostaglandin D2; Prostaglandins; Protein Binding; Protein Processing, Post-Translational; Receptors, Prostaglandin; Signal Transduction

To review our current understanding of the relationship between absorption of nutrients and intestinal inflammatory response.. There is increasing evidence linking gut local inflammatory events with the intake of nutrients. Our recent studies, using the conscious lymph fistula rat model, demonstrate that fat absorption activates the intestinal mucosal mast cells. This is accompanied by a dramatic increase in the lymphatic release of mast cell mediators including histamine, rat mucosal mast cell protease II (RMCPII), as well as the lipid mediator prostaglandin D2 (PGD2). Clinical studies suggest that increased consumption of animal fat may play a role in the pathogenesis of inflammatory bowel disease. This impact of dietary fat may not be restricted to the gut but may extend to the whole body. There is evidence linking a high-fat diet-induced metabolic syndrome, with a low-grade chronic inflammatory state. In this review, we hope to convince the readers that fat absorption can have far reaching physiological and pathophysiological consequences.. Understanding the relationship between nutrient absorption and intestinal inflammation is important. We need a better understanding of the interaction between enterocytes and the intestinal immune cells in nutrient absorption and the gut inflammatory responses.

Topics: Amine Oxidase (Copper-Containing); Animals; Dietary Fats; Disease Models, Animal; Histamine; Inflammation; Inflammatory Bowel Diseases; Intestinal Absorption; Intestinal Mucosa; Mast Cells; Metabolic Syndrome; Prostaglandin D2; Rats; Serine Endopeptidases

Duchenne muscular dystrophy (DMD) is a severe X-linked muscle disease, characterized by progressive skeletal muscle atrophy and weakness. DMD is caused by mutations in the dystrophin gene, which encodes for the cytoskeletal protein dystrophin. DMD is one of the most common types of muscular dystrophies, affecting approximately 1 in 3,500 boys. There is no complete cure for this disease. Clinical trials for gene transfer therapy as a treatment for DMD have been performed but mainly in animal models. Hematopoietic prostaglandin (PG) D synthase (H-PGDS) was found to be induced in grouped necrotic muscle fibers of DMD patients and animal models, mdx mice, and DMD dogs. We found an orally active H-PGDS inhibitor (HQL-79) and determined the 3D structure of the inhibitor-human H-PGDS complex by X-ray crystallography. Oral administration of HQL-79 markedly suppressed prostaglandin D

Topics: Administration, Oral; Animals; Crystallography, X-Ray; Depression, Chemical; Disease Models, Animal; Disease Progression; Dogs; Drug Design; Enzyme Inhibitors; Humans; Intramolecular Oxidoreductases; Lipocalins; Male; Mice; Molecular Targeted Therapy; Muscles; Muscular Dystrophy, Duchenne; Piperidines; Prostaglandin D2

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. PPARgamma regulates several metabolic pathways by binding to sequence-specific PPAR response elements in the promoter region of target genes, including lipid biosynthesis and glucose metabolism. Synthetic PPARgamma agonists have been developed, such as the thiazolidinediones rosiglitazone and pioglitazone. These act as insulin sensitizers and are used in the treatment of type 2 diabetes. Recently however, PPARgamma ligands have been implicated as regulators of cellular inflammatory and immune responses. They are thought to exert anti-inflammatory effects by negatively regulating the expression of pro-inflammatory genes. Several studies have demonstrated that PPARgamma ligands possess anti-inflammatory properties and that these properties may prove helpful in the treatment of inflammatory diseases of the airways. This review will outline the anti-inflammatory effects of synthetic and endogenous PPARgamma ligands and discuss their potential therapeutic effects in animal models of inflammatory airway disease.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Benzimidazoles; Clinical Trials as Topic; Disease Models, Animal; Fatty Acids; Humans; Ligands; PPAR gamma; Prostaglandin D2; Pulmonary Disease, Chronic Obstructive; Pulmonary Fibrosis; Thiazolidinediones

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors that are related to retinoid, steroid and thyroid hormone receptors. The PPAR subfamily comprises three members: PPAR-alpha, PPAR-beta and PPAR-gamma. PPARs have recently been implicated as regulators of cellular proliferation and inflammatory responses. Furthermore, it has been demonstrated that PPAR-gamma and PPAR-alpha reduce lung injury associated with inflammation and shock.

Topics: Animals; Anti-Inflammatory Agents; Disease Models, Animal; Humans; Ligands; PPAR alpha; PPAR gamma; Prostaglandin D2; Respiratory Distress Syndrome; Rosiglitazone; Thiazolidinediones

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

A wide literature exists about the pathogenesis of cerebral arterial spasm following subarachnoid haemorrhage: several compounds have been identified in human cerebrospinal fluid as possible vasoactive agents involved in the biochemical mechanism of vasospasm onset. Many experimental evidences exist for a major involvement of arachidonate metabolites. The present work represents a review of experimental data supporting the hypothesis of cerebral arterial spasm as a result of an imbalanced vascular regulatory mechanism involving arachidonate metabolites. The authors have also monitored, in 25 cases of aneurysmal subarachnoid haemorrhage, lumbar and cisternal CSF levels of prostacyclin and PGD2, as representative of vasodilating and, respectively, vasoconstrictor compounds. In all cases CSF arachidonate metabolite levels after SAH were significantly higher than in control cases. Ten patients presented with symptomatic vasospasm: lumbar CSF PGD2 levels show fluctuations with superimposed peaks related to the neurological deterioration due to vasospasm, while lumbar CSF prostacyclin concentration-trend suggest a decreasing synthesis. In 15 patients presenting without vasospasm, lumbar CSF concentration of arachidonate metabolites are in a 'steady-state'. These data confirm the existence of an imbalanced biochemical situation promoting vasospasm, markedly in cisterns near to the ruptured aneurysmal wall. The evaluation of cisternal CSF levels of arachidonate metabolites supports the hypothesis of the clotting phenomenon around the ruptured aneurysm as an important predictive pattern of vasospasm, as shown in CT findings.

Topics: 6-Ketoprostaglandin F1 alpha; Adolescent; Adult; Aged; Arachidonic Acid; Arachidonic Acids; Disease Models, Animal; Epoprostenol; Female; Humans; Intracranial Aneurysm; Ischemic Attack, Transient; Male; Middle Aged; Prostaglandin D2; Prostaglandins D; Subarachnoid Hemorrhage

Topics: Animals; Antineoplastic Agents; Blood Coagulation; Blood Platelets; Blood Vessels; Cell Adhesion; Cell Communication; Cells, Cultured; Cricetinae; Cysteine Endopeptidases; Disease Models, Animal; Endopeptidases; Epoprostenol; Humans; Killer Cells, Natural; Lung Neoplasms; Melanoma; Mice; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Transplantation; Neoplasms, Experimental; Platelet Aggregation; Prostaglandin D2; Prostaglandins D; Rabbits; Rats; Thrombocytopenia; Thromboxane-A Synthase

We investigated the relevance of the prostaglandin D2 pathway in Alzheimer's disease, because prostaglandin D2 is a major prostaglandin in the brain. Thus, its contribution to Alzheimer's disease merits attention, given the known impact of the prostaglandin E2 pathway in Alzheimer's disease. We used the TgF344-AD transgenic rat model because it exhibits age-dependent and progressive Alzheimer's disease pathology. Prostaglandin D2 levels in hippocampi of TgF344-AD and wild-type littermates were significantly higher than prostaglandin E2. Prostaglandin D2 signals through DP1 and DP2 receptors. Microglial DP1 receptors were more abundant and neuronal DP2 receptors were fewer in TgF344-AD than in wild-type rats. Expression of the major brain prostaglandin D2 synthase (lipocalin-type PGDS) was the highest among 33 genes involved in the prostaglandin D2 and prostaglandin E2 pathways. We treated a subset of rats (wild-type and TgF344-AD males) with timapiprant, a potent highly selective DP2 antagonist in development for allergic inflammation treatment. Timapiprant significantly mitigated Alzheimer's disease pathology and cognitive deficits in TgF344-AD males. Thus, selective DP2 antagonists have potential as therapeutics to treat Alzheimer's disease.

Topics: Alzheimer Disease; Animals; Dinoprostone; Disease Models, Animal; Lipopolysaccharide Receptors; Male; Prostaglandin D2; Prostaglandins; Rats; Rats, Transgenic; Receptors, Immunologic; Receptors, Prostaglandin

Allergic rhinitis (AR) is a common type of inflammatory disease with symptoms including rhinorrhea, fatigue, sneezing, and disturbed sleep. AR affects nearly 40% of peoples worldwide with the increased numbers of new cases. In this work, the study was conducted to disclose the anti-inflammatory and antiallergic properties of cirsilineol against the ovalbumin (OVA)-sensitized AR in mice. AR was provoked in BALB/c mice through the OVA challenge 30 days along with 10 and 20 mg/kg of cirsilineol treatment. The nasal symptoms, i.e., rubbing and sneezing was monitored after the final OVA challenge. The status of OVA-specific IgE, PGD2, and LTC4 was investigated using assay kits. The status of pro-inflammatory markers also examined using assay kits. The levels of oxidative markers, SOD activity, and pro-inflammatory markers in the spleen mononuclear cells (SMEs) were studied by using respective assay kits. The mRNA expression of TXNIP was assessed using RT-PCR study. The 10 and 20 mg/kg of cirsilineol treatment effectively decreased the sneezing and nasal rubbings in OVA-provoked mice. Cirsilineol also decreased the IgE, PGD2, and LTC4 status in the AR animals. The status of pro-inflammatory markers, i.e., IL-4, IL-5, IL-6, IL-33 and TNF-α was found to be decreased in the cirsilineol administered AR mice. Cirsilineol effectively reduced the ROS and MDA and improved SOD in the OVA-challenged SMCs. The mRNA expression of TXNIP was appreciably suppressed by the cirsilineol treatment. Altogether, these findings proved the beneficial actions of cirsilineol against the OVA-triggered AR in mice. The additional studies on the cirsilineol could lead to the development of new drug for AR management.

Topics: Animals; Anti-Allergic Agents; Biomarkers; Carrier Proteins; Cells, Cultured; Disease Models, Animal; Eosinophils; Flavones; Histamine; Immunoglobulin E; Leukotriene C4; Mice, Inbred BALB C; Nasal Lavage Fluid; Ovalbumin; Oxidative Stress; Prostaglandin D2; Rhinitis, Allergic; Spleen; Thioredoxins

Uncontrolled macrophage functions cause failure to resolve gut inflammation and has been implicated in the pathogenesis of inflammatory bowel disease (IBD). 15-Deoxy-Δ

Topics: Animals; Anti-Inflammatory Agents; Biomarkers; Colitis; Dextran Sulfate; Disease Models, Animal; Immunologic Factors; Intestinal Mucosa; Macrophages; Male; Mice; Prostaglandin D2; STAT3 Transcription Factor; Treatment Outcome

Group 2 innate lymphoid cells (ILC2s) are rare innate immune cells that accumulate in tissues during allergy and helminth infection, performing critical effector functions that drive type 2 inflammation. ILC2s express ST2, the receptor for the cytokine IL-33, and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2), a receptor for the bioactive lipid prostaglandin D

Topics: Adoptive Transfer; Animals; Cell Movement; Cell Proliferation; Cells, Cultured; Disease Models, Animal; Female; Humans; Hypersensitivity; Immunity, Innate; Interleukin-33; Lung; Lymphocytes; Mice; Mice, Knockout; Nippostrongylus; Primary Cell Culture; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Recombinant Proteins; Strongylida Infections

Nasal obstruction is one of the most bothersome symptoms of allergic rhinitis (AR) affecting sleep-related quality of life in AR patients. Although several treatments were tested to control nasal obstruction, some patients with moderate to severe AR do not respond to current treatments, including the combined administration of different types of anti-allergic medicine. Thus, new options for AR treatment are needed. This study aimed to evaluate the effects of combined treatment with a novel inhibitor of hematopoietic prostaglandin D synthase (HPGDS), TAS-205, and different types of anti-allergic medicine on nasal obstruction in AR. Firstly, we demonstrated that TAS-205 selectively inhibited prostaglandin D

Topics: Acetates; Animals; Anti-Allergic Agents; Cell Line; Cyclopropanes; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Enzyme Inhibitors; Guinea Pigs; Humans; Intramolecular Oxidoreductases; Lipocalins; Male; Morpholines; Nasal Mucosa; Nasal Obstruction; Ovalbumin; Piperidines; Prostaglandin D2; Pyrroles; Quality of Life; Quinolines; Rats; Rhinitis, Allergic; Sulfides; Terfenadine

Painful conditions of the temporomandibular joint (TMJ) are challenging to manage and most attempts often result in unsatisfactory outcomes. In such context, nanocarrier systems, such as polymeric micelles, have been showing encouraging results in solving therapeutic limitations. Poloxamers are widely used, especially PL 407, because of their high biocompatibility and approval by the Food and Drug Administration (FDA) for clinical use. 15-deoxy-

Topics: Animals; Anti-Inflammatory Agents; Arthralgia; Biological Availability; Chemotaxis, Leukocyte; Cytokines; Disease Models, Animal; Drug Carriers; Drug Compounding; Formaldehyde; Inflammation Mediators; Injections, Intra-Articular; Leukocytes; Male; Micelles; Poloxamer; Prostaglandin D2; Rats, Wistar; Temporomandibular Joint; Temporomandibular Joint Disorders; Tissue Distribution

Topics: Adoptive Transfer; Animals; B7-H1 Antigen; Biomarkers; Dendritic Cells; Disease Models, Animal; Disease Susceptibility; Encephalomyelitis, Autoimmune, Experimental; Lymphocyte Activation; Lymphocyte Count; Mice; Mice, Knockout; Programmed Cell Death 1 Receptor; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Signal Transduction; T-Cell Antigen Receptor Specificity; T-Lymphocyte Subsets

Development of pancreatic ductal adenocarcinoma (PDA) involves acinar to ductal metaplasia and genesis of tuft cells. It has been a challenge to study these rare cells because of the lack of animal models. We investigated the role of tuft cells in pancreatic tumorigenesis.. We performed studies with LSL-Kras. Pancreata from KC mice had increased formation of tuft cells and higher levels of prostaglandin D. In mice with KRAS-induced pancreatic tumorigenesis, loss of tuft cells accelerates tumorigenesis and increases the severity of caerulein-induced pancreatic injury, via decreased production of prostaglandin D

Topics: Animals; Carcinoma, Pancreatic Ductal; Cell Transformation, Neoplastic; Ceruletide; Disease Models, Animal; Energy Metabolism; Fibrosis; Humans; Interleukins; Intramolecular Oxidoreductases; Mice, Transgenic; Mutation; Octamer Transcription Factors; Pancreas; Pancreatic Neoplasms; Pancreatitis; Prostaglandin D2; Proto-Oncogene Proteins p21(ras); Time Factors; Transcription Factors

Aiming to delineate novel neuro-immune mechanisms for NGF/TrkA signalling in osteoarthritis (OA) pain, we evaluated inflammatory changes in the knee joints following injection of monoiodoacetate (MIA) in mice carrying a TrkA receptor mutation (P782S; TrkA KI mice).. In behavioural studies we monitored mechanical hypersensitivity following intra-articular MIA and oral prostaglandin D. In TrkA KI mice we observed rapid development of mechanical hypersensitivity and amplification of dorsal horn neurons and microglia activation 7 days after MIA. In TrkA KI knee joints we detected significant leukocyte infiltration and mast cells located in the vicinity of synovial nociceptive fibres. We demonstrated that mast cells exposure to NGF results in up-regulation of COX-2 and increase of PGD. Using the TrkA KI mouse model, we delineated a novel neuro-immune pathway and suggest that NGF-induced production of PGD

Topics: Animals; Arthritis, Experimental; Cartilage Diseases; Cartilage, Articular; Cyclooxygenase 2; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Enzyme Inhibitors; Female; Injections, Intra-Articular; Intramolecular Oxidoreductases; Iodoacetic Acid; Lipocalins; Macrophages; Male; Mast Cells; Mice, Inbred C57BL; Osteoarthritis, Knee; Prostaglandin D2; Receptor, trkA; Stifle; T-Lymphocytes; Up-Regulation

This study aimed to explore the effect of microRNA-592-5p (miR-592-5p) on hypoxic-ischemic brain damage (HIBD)-induced hippocampal neuronal injury in a neonatal mouse model relative to the involvement of one target gene, PTGDR, and the PGD2/ DP signaling pathway.. A total of 30 neonatal mice aged 7 days were randomly selected to establish an HIBD mouse model. Hippocampal neuronal cells were transfected into a control group, a blank group, a negative control (NC) group, an miR-592-5p mimics group, an miR-592-5p inhibitors group, an siRNA-PTGDR group and an miR-592-5p inhibitors + siRNA-PTGDR group. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analyses were performed to detect the expression levels of miR-592-5p, PTGDR, DP2, Bcl-2 and Bax in tissues and cells. Cell proliferation, cell cycle and apoptosis were detected by MTT assay and flow cytometry, respectively.. The expression levels of miR-592-5p and Bcl-2 decreased, while the expression levels of PTGDR, DP2 and Bax increased in the HIBD group. PTGDR is a target gene of miR-592-2p. Compared with the NC and blank groups, the expression levels of PTGDR, DP2 and Bax decreased, while the expression levels of miR-592-5p and Bcl-2 increased in the miR-592-5p mimics group. The siRNA-PTGDR group showed the same trend as that observed in the miR-592-5p mimics group, except with no difference in miR-592-5p expression. The miR-592-5p inhibitors group showed an opposite gene expression trend compared to that in the miR-592-5p mimics group. The S phase of the cell cycle was prolonged, the G1 phase was reduced, proliferation was increased, and the apoptosis rate was decreased in the siRNA-PTGDR and miR-592-5p mimics groups. Opposite trends for cell cycle, proliferation and apoptosis were observed in the miR-592-5p inhibitors group.. Our study suggests that miR-592-5p upregulation protects against hippocampal neuronal injury caused by HIBD by targeting PTGDR and inhibiting the PGD2/DP signaling pathway.

Topics: Animals; Animals, Newborn; Apoptosis; bcl-2-Associated X Protein; Cell Proliferation; Cells, Cultured; Disease Models, Animal; DNA-Binding Proteins; Hippocampus; Hypoxia-Ischemia, Brain; Mice; MicroRNAs; Neurons; Prostaglandin D2; Proto-Oncogene Proteins c-bcl-2; Receptors, Immunologic; Receptors, Prostaglandin; RNA Interference; Signal Transduction; Transcription Factors; Up-Regulation

Topics: Animals; Anti-Inflammatory Agents; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Asthma; Dexamethasone; Dinoprostone; Disease Models, Animal; Fatty Acids, Omega-3; Humans; Hypersensitivity; Inflammation; Mice; Mice, Inbred C57BL; Mice, Knockout; Prostaglandin D2; Respiratory Hypersensitivity

Conventional allergic rhinitis (AR) treatments have limitations due to the lack of safety and complete cure strategy. We evaluated the effects of silent information regulator 1 (SIRT1), a multifunctional molecule involved in a variety of inflammatory pathways, on murine AR model. Ovalbumin (OVA)-induced murine model was constructed, and recombinant SIRT1 was administered into the nostril continuously. The expression of SIRT1 was measured at mRNA and protein levels, and the allergic symptoms were evaluated. Protein levels of OVA-specific IgE, leukotriene C4 (LTC4), eosinophil cation protein (ECP), prostaglandin D2 (PGD2), as well as different inflammatory cytokine mediators in the serum and nasal lavage fluid (NLF), were assessed by ELISA. The effects of SIRT1 on human primary nasal epithelial cells challenged with tumour necrosis factor (TNF)-α were also evaluated by investigating the HMGB1/TLR4 signalling pathway. Administration of SIRT1 significantly alleviated OVA-induced AR symptoms with lower numbers of sneezing and nasal rubbing events, decreased levels of OVA-specific IgE, LTC4, ECP, PGD2, less inflammatory cells and downregulated levels of Th2 type cytokines. SIRT1 also reduced the genes of HMGB1/TLR4 signalling pathway in the murine model and cultured human nasal epithelial cells. Expression of SIRT1 is impaired in OVA-induced AR model. The administration of SIRT1 alleviates the allergic symptoms of mice, regulates the production of pro-inflammatory mediators predominantly produced by Th2 cells in AR and attenuates expressions of proteins relevant to HMGB1/TLR4 signalling pathway. All the results showed that SIRT1 is promising as a therapeutic agent of AR.

Topics: Animals; Cells, Cultured; Disease Models, Animal; Down-Regulation; Eosinophil Cationic Protein; Female; HMGB1 Protein; Humans; Immunoglobulin E; Leukotriene C4; Mice; Mice, Inbred BALB C; Nasal Lavage Fluid; Nasal Mucosa; Ovalbumin; Prostaglandin D2; Recombinant Proteins; Rhinitis, Allergic; Signal Transduction; Sirtuin 1; Th2 Cells; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Prostaglandins are products of the cyclooxygenase pathway, which is implicated in Parkinson's disease (PD). Limited knowledge is available on mechanisms by which prostaglandins contribute to PD neurodegeneration. To address this gap, we focused on the prostaglandin PGD2/J2 signaling pathway, because PGD2 is the most abundant prostaglandin in the brain, and the one that increases the most under pathological conditions. Moreover, PGJ2 is spontaneously derived from PGD2.. In this study, we determined in rats the impact of unilateral nigral PGJ2-microinfusions on COX-2, lipocalin-type PGD2 synthase (L-PGDS), PGD2/J2 receptor 2 (DP2), and 15 hydroxyprostaglandin dehydrogenase (15-PGDH). Nigral dopaminergic (DA) and microglial distribution and expression levels of these key factors of the prostaglandin D2/J2 pathway were evaluated by immunohistochemistry. PGJ2-induced motor deficits were assessed with the cylinder test. We also determined whether oral treatment with ibuprofen improved the PD-like pathology induced by PGJ2.. PGJ2 treatment induced progressive PD-like pathology in the rats. Concomitant with DA neuronal loss in the substantia nigra pars compacta (SNpc), PGJ2-treated rats exhibited microglia and astrocyte activation and motor deficits. In DA neurons, COX-2, L-PGDS, and 15-PGDH levels increased significantly in PGJ2-treated rats compared to controls, while DP2 receptor levels were unchanged. In microglia, DP2 receptors were basically non-detectable, while COX-2 and L-PGDS levels increased upon PGJ2-treatment, and 15-PGDH remained unchanged. 15-PGDH was also detected in oligodendrocytes. Notably, ibuprofen prevented most PGJ2-induced PD-like pathology.. The PGJ2-induced rat model develops progressive PD pathology, which is a hard-to-mimic aspect of this disorder. Moreover, prevention of most PGJ2-induced PD-like pathology with ibuprofen suggests a positive feedback mechanism between PGJ2 and COX-2 that could lead to chronic neuroinflammation. Notably, this is the first study that analyzes the nigral dopaminergic and microglial distribution and levels of factors of the PGD2/J2 signaling pathway in rodents. Our findings support the notions that upregulation of COX-2 and L-PGDS may be important in the PGJ2 evoked PD-like pathology, and that neuronal DP2 receptor antagonists and L-PGDS inhibitors may be novel pharmacotherapeutics to relieve neuroinflammation-mediated neurodegeneration in PD, circumventing the adverse side effects of cyclooxygenase inhibitors.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Disease Models, Animal; Encephalitis; Exploratory Behavior; Functional Laterality; Ibuprofen; Male; Microglia; Neurons; Parkinsonian Disorders; Phosphopyruvate Hydratase; Prostaglandin D2; Psychomotor Performance; Rats; Signal Transduction; Substantia Nigra; Tyrosine 3-Monooxygenase

During respiratory viral infection, conventional dendritic cells (cDCs) take up antigen and migrate to the draining lymph nodes to present viral antigen and activate cytotoxic T lymphocytes; however, regulation of cDC activation and migration may be age dependent. In this study, we used a mouse model of paramyxoviral infection (Sendai virus) and demonstrated that cDCs, which have migrated from lungs to the draining lymph nodes, are delayed in expressing activation markers in neonatal mice compared with adults. Neonatal lung cDCs expressed reduced levels of MHC Class II (major histocompatibility complex II) and CCR7 (chemokine receptor type 7) on postinfection days 3 and 5, respectively. The level of the CCR7 ligand CCL19 was significantly reduced in neonatal lungs during the course of viral infection. Interestingly, the arachidonic acid metabolite prostaglandin D

Topics: Animals; Animals, Newborn; Antigens, CD; Bronchoalveolar Lavage Fluid; Cells, Cultured; Cytokines; Dendritic Cells; Disease Models, Animal; Epithelial Cells; Humans; Integrin alpha Chains; Intramolecular Oxidoreductases; Lipocalins; Lung; Mice; Primary Cell Culture; Prostaglandin D2; Receptors, CCR7; Receptors, Prostaglandin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Thymic Stromal Lymphopoietin; Trachea

Prostaglandin D2 (PGD2) is a lipid mediator involved in sleep regulation and inflammation. PGD2 interacts with 2 types of G protein-coupled receptors, DP1 and DP2/CRTH2 (chemoattractant receptor homologous molecule expressed on T helper type 2 cells)/GPR44 to show a variety of biological effects. DP1 activation leads to Gs-mediated elevation of the intracellular cAMP level, whereas activation of DP2 decreases this level via the Gi pathway; and it also induces G protein-independent, arrestin-mediated cellular responses. Activation of DP2 by PGD2 causes the progression of inflammation via the recruitment of lymphocytes by enhancing the production of Th2-cytokines. Here we developed monoclonal antibodies (MAbs) against the extracellular domain of mouse DP2 by immunization of DP2-null mutant mice with DP2-overexpressing BAF3, murine interleukin-3 dependent pro-B cells, to reduce the generation of antibodies against the host cells by immunization of mice. Moreover, we immunized DP2-KO mice to prevent immunological tolerance to mDP2 protein. After cell ELISA, immunocytochemical, and Western blot analyses, we successfully obtained a novel monoclonal antibody, MAb-1D8, that specifically recognized native mouse DP2, but neither human DP2 nor denatured mouse DP2, by binding to a particular 3D receptor conformation formed by the N-terminus and extracellular loop 1, 2, and 3 of DP2. This antibody inhibited the binding of 0.5 nM [3H]PGD2 to mouse DP2 (IC50 = 46.3 ± 18.6 nM), showed antagonistic activity toward 15(R)-15-methyl PGD2-induced inhibition of 300 nM forskolin-activated cAMP production (IC50 = 16.9 ± 2.6 nM), and gave positive results for immunohistochemical staining of DP2-expressing CD4+ Th2 lymphocytes that had accumulated in the kidney of unilateral ureteral obstruction model mice. This monoclonal antibody will be very useful for in vitro and in vivo studies on DP2-mediated diseases.

Topics: Animals; Antibodies, Monoclonal; Antibody Specificity; beta-Arrestins; CD4-Positive T-Lymphocytes; CHO Cells; COS Cells; Cricetulus; Cyclic AMP; Disease Models, Animal; Epitope Mapping; HEK293 Cells; Humans; Hybridomas; Immunization; Immunohistochemistry; Kidney; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Precursor Cells, B-Lymphoid; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Ureteral Obstruction

Hydrogen sulfide reduces ventilator-induced lung injury in mice. Here, we have examined the underlying mechanisms of hydrogen sulfide-mediated lung protection and determined the involvement of cyclooxygenase 2, 15-deoxy Δ-prostaglandin J2, and peroxisome proliferator-activated receptor gamma in this response.. Randomized, experimental study.. University medical center research laboratory.. C57BL/6 mice and in vitro cell catheters.. The effects of hydrogen sulfide were analyzed in a mouse ventilator-induced lung injury model in vivo as well as in a cell stretch model in vitro in the absence or presence of hydrogen sulfide. The physiologic relevance of our findings was confirmed using pharmacologic inhibitors of cyclooxygenase 2 and peroxisome proliferator-activated receptor gamma.. Mechanical ventilation caused significant lung inflammation and injury that was prevented in the presence of hydrogen sulfide. Hydrogen sulfide-mediated protection was associated with induction of cyclooxygenase 2 and increases of its product 15-deoxy Δ-prostaglandin J2 as well as cyclooxygenase 2/15-deoxy Δ-prostaglandin J2-dependent activation of peroxisome proliferator-activated receptor gamma. Hydrogen sulfide-dependent effects were mainly observed in macrophages. Applied mechanical stretch to RAW 264.7 macrophages resulted in increased expression of interleukin receptor 1 messenger RNA and release of macrophage inflammatory protein-2. In contrast, incubation of stretched macrophages with sodium hydrosulfide prevented the inflammatory response dependent on peroxisome proliferator-activated receptor gamma activity. Finally, application of a specific peroxisome proliferator-activated receptor gamma inhibitor abolished hydrogen sulfide-mediated protection in ventilated animals.. One hydrogen sulfide-triggered mechanism in the protection against ventilator-induced lung injury involves cyclooxygenase 2/15-deoxy Δ-prostaglandin J2-dependent activation of peroxisome proliferator-activated receptor gamma and macrophage activity.

Topics: Animals; Cyclooxygenase 2; Disease Models, Animal; Hydrogen Sulfide; Male; Mice; Mice, Inbred C57BL; PPAR gamma; Prostaglandin D2; Ventilator-Induced Lung Injury

Topics: Anaphylaxis; Animals; Biomarkers; Blood Pressure; Capillary Permeability; Cell Degranulation; Disease Models, Animal; Inflammation Mediators; Mast Cells; Mice; Prostaglandin D2

iNKT cells and mast cells have both been implicated in the syndrome of allergic asthma through their activation-induced release of Th2 type cytokines and secretion of histamine and other mediators, respectively, which can promote airways hyperresponsiveness (AHR) to agents such as methacholine. However, a mechanistic link between iNKT cells and mast cell recruitment or activation has never been explored. Our objective was to determine whether iNKT cells are necessary for the recruitment of mast cells and if iNKT cells can influence the acute allergen induced bronchoconstriction (AIB) caused by mast cell mediator release. To do so, we pharmacologically eliminated iNKT cells using a specific antibody (NKT-14) and examined its impact on airway inflammation and physiological phenotype. In mice treated with NKT-14, the elimination of iNKT cells was sufficient to prevent AHR and pulmonary eosinophilic inflammation elicited by administration of the iNKT cell agonist αGalCer. In mice treated with NKT-14 and then sensitized and challenged with house dust mite extract (HDM), eliminating the iNKT cells significantly reduced both AHR and AIB but did not affect pulmonary inflammation, the mast cell population, nor the release of the mast cell mediators mast cell protease-1 and prostaglandin D2. We conclude that while iNKT cells contribute to the phenotype of allergic airways disease through the manifestation of AIB and AHR, their presence is not required for mast cell recruitment and activation, or to generate the characteristic inflammatory response subsequent to allergen challenge.

Topics: Allergens; Animals; Bronchoconstriction; Chymases; Disease Models, Animal; Eosinophils; Female; Hypersensitivity; Inflammation; Lung; Mast Cells; Mice; Mice, Inbred BALB C; Natural Killer T-Cells; Phenotype; Prostaglandin D2; Pyroglyphidae; Respiratory Hypersensitivity

Prostaglandin (PG) D2 is the most abundant prostaglandin in the mammalian brain. The physiological and pharmacological actions of PGD2 in the central nervous system seem to be associated with some of the symptoms exhibited by patients with major depressive disorder. Previous studies have found that PGD2 synthase was decreased in the cerebrospinal fluid of major depressive disorder patients. We speculated that there may be a dysregulation of PGD2 levels in major depressive disorder.. Ultra-performance liquid chromatography-tandem mass spectrometry coupled with a stable isotopic-labeled internal standard was used to determine PGD2 levels in the plasma of major depressive disorder patients and in the brains of depressive mice. A total of 32 drug-free major depressive disorder patients and 30 healthy controls were recruited. An animal model of depression was constructed by exposing mice to 5 weeks of chronic unpredictable mild stress. To explore the role of PGD2 in major depressive disorder, selenium tetrachloride was administered to simulate the change in PGD2 levels in mice.. Mice exposed to chronic unpredictable mild stress exhibited depression-like behaviors, as indicated by reduced sucrose preference and increased immobility time in the forced swimming test. PGD2 levels in the plasma of major depressive disorder patients and in the brains of depressive mice were both decreased compared with their corresponding controls. Further inhibiting PGD2 production in mice resulted in an increased immobility time in the forced swimming test that could be reversed by imipramine.. Decreased PGD2 levels in major depressive disorder are associated with depression-like behaviors.

Topics: Adolescent; Adult; Animals; Antidepressive Agents, Tricyclic; Antioxidants; Brain; Chromatography, Liquid; Depression; Depressive Disorder, Major; Disease Models, Animal; Dose-Response Relationship, Drug; Exploratory Behavior; Female; Food Preferences; Humans; Imipramine; Male; Mice; Mice, Inbred C57BL; Middle Aged; Prostaglandin D2; Selenium; Stress, Psychological; Swimming; Tandem Mass Spectrometry; Young Adult

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

To investigate the effects of particulate matter ≤ 2.5 microns (PM2.5) on asthma-related phenotypes and on lung expression of TRPA1 and TRPV1 proteins in a mouse model of asthma.. Female BALB/c mice were utilized to establish 28- and 42-day asthma models. Mice were sensitized with ovalbumin (OVA) and challenged with OVA, OVA plus normal saline (NS), or OVA plus PM2.5 at two doses, 1.6 or 8.0 mg kg. PM2.5 treated mice showed significantly greater changes in the number of inflammatory cells in blood and BALF, in RI and Cdyn in response to ACH, and in lung histopathology, indicated by inflammatory cell infiltration, thickened bronchial smooth muscles and bronchial mucosa damage, compared to controls. In addition, higher expression of TRPA1 and TRPV1 in lung and IL-13, SP, PGD. PM2.5 exacerbates effects of asthma in this model, possibly by regulating TRPA1 and TRPV1 and the relevant neurokines.

Topics: Airway Resistance; Animals; Asthma; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Eosinophils; Female; Interleukin-13; Mice; Mice, Inbred BALB C; Nerve Growth Factor; Ovalbumin; Particulate Matter; Prostaglandin D2; Respiratory Mechanics; Substance P; Transient Receptor Potential Channels; TRPA1 Cation Channel; TRPV Cation Channels

IgE/Ag-stimulated mast cells release various pro-allergic inflammatory mediators, including histamine, eicosanoids, and pro-inflammatory cytokines. NecroX-5, a cell permeable necrosis inhibitor, showed cytoprotective effects in both in vitro and in vivo models. However, the anti-allergic effect of NecroX-5 has not yet been investigated. The aims of this study were to evaluate the anti-allergic activity of NecroX-5 in vivo and to investigate the underlying mechanism in vitro.. The anti-allergic activity of NecroX-5 was evaluated in vitro using bone marrow-derived mast cells (BMMCs) and IgE receptor-bearing RBL-2H3 or KU812 cells and in vivo using a mouse model of passive anaphylaxis. The levels of histamine, eicosanoids (PGD2 and LTC4 ), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured using enzyme immunoassay kits. The mechanism underlying the action of NecroX-5 was investigated using immunoblotting, immunoprecipitation, and gene knockdown techniques.. NecroX-5 markedly inhibited mast cell degranulation and the synthesis of eicosanoids, TNF-α, and IL-6 by suppressing the activation of Syk, LAT, phospholipase Cγ1, MAP kinases, the Akt/NF-κB pathway, and intracellular Ca(2+) mobilization via the activation of phosphatase SHP-1. Oral administration of NecroX-5 effectively suppressed mast cell-dependent passive cutaneous and systemic anaphylactic reactions in a dose-dependent manner.. NecroX-5 might be a potential candidate for the development of a novel anti-allergic agent that suppresses IgE-dependent mast cells signaling.

Topics: Anaphylaxis; Animals; Antigens; Arachidonate 5-Lipoxygenase; Calcium; Cell Degranulation; Cell Line; Cyclooxygenase 2; Cytokines; Disease Models, Animal; Heterocyclic Compounds, 4 or More Rings; Immunoglobulin E; Intracellular Signaling Peptides and Proteins; Leukotriene C4; Male; Mast Cells; Mice; Prostaglandin D2; Protein Binding; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Protein-Tyrosine Kinases; Signal Transduction; Sulfones; Syk Kinase

Germinal matrix hemorrhage remains the leading cause of morbidity and mortality in preterm infants in the United States with little progress made in its clinical management. Survivors are often afflicted with long-term neurological sequelae, including cerebral palsy, mental retardation, hydrocephalus, and psychiatric disorders. Blood clots disrupting normal cerebrospinal fluid circulation and absorption after germinal matrix hemorrhage are thought to be important contributors towards post-hemorrhagic hydrocephalus development. We evaluated if upregulating CD36 scavenger receptor expression in microglia and macrophages through PPARγ stimulation, which was effective in experimental adult cerebral hemorrhage models and is being evaluated clinically, will enhance hematoma resolution and ameliorate long-term brain sequelae using a neonatal rat germinal matrix hemorrhage model. PPARγ stimulation (15d-PGJ2) increased short-term PPARγ and CD36 expression levels as well as enhanced hematoma resolution, which was reversed by a PPARγ antagonist (GW9662) and CD36 siRNA. PPARγ stimulation (15d-PGJ2) also reduced long-term white matter loss and post-hemorrhagic ventricular dilation as well as improved neurofunctional outcomes, which were reversed by a PPARγ antagonist (GW9662). PPARγ-induced upregulation of CD36 in macrophages and microglia is, therefore, critical for enhancing hematoma resolution and ameliorating long-term brain sequelae.

Topics: Anilides; Animals; Animals, Newborn; Brain; CD36 Antigens; Central Nervous System Agents; Disease Models, Animal; Gene Knockdown Techniques; Hematoma; Intracranial Hemorrhages; Macrophage Activation; Microglia; Neuroprotective Agents; PPAR gamma; Prostaglandin D2; Random Allocation; Rats, Sprague-Dawley; RNA, Small Interfering; Up-Regulation

Asthma, a multifactorial, chronic inflammatory disease encompasses multiple complex pathways releasing number of mediators by activated mast cells, eosinophils and T lymphocytes, leading to its severity. Presently available medications are associated with certain limitations, and hence, it is imperative to search for anti-inflammatory drug preferably targeting signaling cascades involved in inflammation thereby suppressing inflammatory mediators without any side effect. Curcumin, an anti-inflammatory molecule with potent anti-asthmatic potential has been found to suppress asthmatic features by inhibiting airway inflammation and bronchoconstriction if administered through nasal route. The present study provides new insight towards anti-asthmatic potential of intranasal curcumin at lower doses (2.5 and 5.0 mg/kg) in Balb/c mice sensitized and challenged with ovalbumin (OVA) which is effective in inhibiting airway inflammation. These investigations suggest that intranasal curcumin (2.5 and 5.0 mg/kg) regulates airway inflammation and airway obstruction mainly by modulating cytokine levels (IL-4, 5, IFN-ƴ and TNF-α) and sPLA2 activity thereby inhibiting PGD2 release and COX-2 expression. Further, the suppression of p38 MAPK, ERK 42/44 and JNK54/56 activation elucidate the mechanism behind the inhibitory role of intranasal curcumin in asthma progression. Thus, curcumin could be better alternative for the development of nasal formulations and inhalers in near future.

Topics: Administration, Intranasal; Airway Obstruction; Animals; Asthma; Curcumin; Cytokines; Disease Models, Animal; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Humans; MAP Kinase Kinase 4; Mice; Mice, Inbred BALB C; p38 Mitogen-Activated Protein Kinases; Prostaglandin D2

15-Deoxy-delta (12,14)-prostaglandin J2 (15d-PgJ2) is a potent bioactive lipid mediator, known to possess several roles in cell regulation and differentiation along with antimicrobial efficacy against different bacterial and viral infections. In the present study, we investigated the therapeutic efficacy and mechanism of action of 15d-PgJ2 in vitro in Leishmania donovani promastigotes and infected J774 macrophages, and in vivo in Balb/c mice/golden hamster model of experimental visceral leishmaniasis. 15d-PgJ2 effectively killed L. donovani promastigotes and amastigotes in vitro with IC50 of 104.6 and 80.09 nM, respectively. At 2 mg/kg (mice) and 4 mg/kg (hamster) doses, 15d-PgJ2 decreased >90 % spleen and liver parasite burden. It significantly reduced interleukin (IL)-10 and transforming growth factor (TGF)-β synthesis in infected macrophages and splenocytes. 15d-PgJ2 induced reactive oxygen species (ROS)-dependent apoptosis of promastigotes by triggering phosphatidyl serine externalization, mitochondrial membrane damage and inducing caspase-like activity. In vitro drug interaction studies revealed an indifference to the synergistic association of 15d-PgJ2 with Miltefosine and Amphotericin-B (Amp-B). Moreover, when combined with sub-curative doses of Miltefosine and Amphotericin-B, 15d-PgJ2 resulted in >95 % parasite removal. Our results suggested that 15d-PgJ2 induces mitochondria-dependent apoptosis of L. donovani and is a good therapeutic candidate for adjunct therapy against experimental visceral leishmaniasis.. 15d-PgJ2 effectively eliminated both promastigotes and amastigotes form of L. donovani. 15d-PgJ2 decreased parasite burden from infected mice and hamsters with reduced Th2 cytokines. 15d-PgJ2 induced ROS-mediated mitochondrial apoptosis of L. donovani promastigotes. 15d-PgJ2 is a good therapeutic candidate for adjunct therapy with Miltefosine and Amp-B.

Topics: Amphotericin B; Animals; Antiprotozoal Agents; Apoptosis; Cell Line; Cricetulus; Disease Models, Animal; Drug Administration Schedule; Female; Interleukin-10; Leishmania donovani; Leishmaniasis, Visceral; Life Cycle Stages; Liver; Macrophages; Male; Mice; Mice, Inbred BALB C; Mitochondria; Phosphorylcholine; Prostaglandin D2; Reactive Oxygen Species; Spleen; Transforming Growth Factor beta; Treatment Outcome

In allergen-induced asthma, activated mast cells start the lung inflammatory process with degranulation, cytokine synthesis, and mediator release. Bruton's tyrosine kinase (Btk) activity is required for the mast cell activation during IgE-mediated secretion.. This study characterized a novel inhaled Btk inhibitor RN983 in vitro and in ovalbumin allergic mouse models of the early (EAR) and late (LAR) asthmatic response.. RN983 potently, selectively, and reversibly inhibited the Btk enzyme. RN983 displayed functional activities in human cell-based assays in multiple cell types, inhibiting IgG production in B-cells with an IC50 of 2.5 ± 0.7 nM and PGD2 production from mast cells with an IC50 of 8.3 ± 1.1 nM. RN983 displayed similar functional activities in the allergic mouse model of asthma when delivered as a dry powder aerosol by nose-only inhalation. RN983 was less potent at inhibiting bronchoconstriction (IC50(RN983) = 59 μg/kg) than the β-agonist salbutamol (IC50(salbutamol) = 15 μg/kg) in the mouse model of the EAR. RN983 was more potent at inhibiting the antigen induced increase in pulmonary inflammation (IC50(RN983) = <3 μg/kg) than the inhaled corticosteroid budesonide (IC50(budesonide) = 27 μg/kg) in the mouse model of the LAR.. Inhalation of aerosolized RN983 may be effective as a stand-alone asthma therapy or used in combination with inhaled steroids and β-agonists in severe asthmatics due to its potent inhibition of mast cell activation.

Topics: Administration, Inhalation; Adrenergic beta-2 Receptor Agonists; Agammaglobulinaemia Tyrosine Kinase; Albuterol; Animals; Anti-Asthmatic Agents; Anti-Inflammatory Agents; Asthma; B-Lymphocytes; Bronchial Hyperreactivity; Bronchoconstriction; Bronchodilator Agents; Budesonide; Cell Degranulation; Cells, Cultured; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Dry Powder Inhalers; Glucocorticoids; Humans; Immunoglobulin G; Lung; Male; Mast Cells; Mice, Inbred BALB C; Ovalbumin; Phthalazines; Pneumonia; Prostaglandin D2; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyridazines

In this study, we confirmed a protective effect of 15d-PGJ2 in concanavalin A (ConA)-induced fulminant hepatitis in mice and investigated the potential mechanism.. Balb/C mice were injected with ConA (25mg/kg) to induce acute fulminant hepatitis, and 15d-PGJ2 (2.5-10μg) was administered 30min after the ConA injection. The histological grade, pro-inflammatory cytokine and ROS levels, apoptosis and autophagy activity, the expression of HO-1, Nrf2, JNK and Bcl-2 activity were determined 2, 4, and 8h after the ConA injection.. Following ConA challenge, the expression of cytokines tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) was up-regulated. Treatment with 15d-PGJ2 reduced the pathological effects of ConA-induced fulminant hepatitis and significantly reduced the levels of TNF-α, IL-1β and ROS after injection. 15d-PGJ2 inhibited apoptosis and autophagic cell death, facilitated Nrf2 nuclear translocation, increased HO-1 expression and suppressed the JNK activation.. 15d-PGJ2 alleviates ConA-induced acute liver injury in mice by up-regulating the anti-oxidative stress factor HO-1 and reducing the production of cytokines and ROS, thereby inhibiting hepatic cell autophagy probably induced by ROS.

Topics: Acute Disease; Animals; Autophagy; Cell Nucleus; Concanavalin A; Disease Models, Animal; Enzyme Activation; Heme Oxygenase-1; Hepatitis; Hepatocytes; Interleukin-1beta; JNK Mitogen-Activated Protein Kinases; Liver; Male; Mice, Inbred BALB C; NF-E2-Related Factor 2; Phagosomes; Prostaglandin D2; Reactive Oxygen Species; Tumor Necrosis Factor-alpha; Up-Regulation

Chemoattractant receptor-homologous molecule expressed on T helper type 2 cells (CRTH2), which is a second receptor for prostaglandin (PG) D2, is involved in inflammatory responses in peripheral tissue; however, its role in cognitive function remains unclear. Here, we demonstrate that CRTH2 is involved in cognitive function using a well-established animal model of cognitive dysfunction induced by MK-801, an N-methyl-d-aspartate receptor antagonist. Genetic deletion and pharmacological inhibition of CRTH2 suppressed MK-801-induced cognitive dysfunction. Pharmacological inhibition of cyclooxygenase-1, a rate-limiting enzyme in PG synthesis, also suppressed MK-801-induced cognitive dysfunction. Moreover, an MK-801-induced increase in c-Fos expression in the paraventricular nucleus (PVN) was abolished in the CRTH2-deficient mice. Together, these results suggest that PGD2-CRTH2 signaling is involved in both MK-801-induced cognitive dysfunction and neuronal activity regulation in the PVN. Furthermore, genetic association studies suggest that CRTH2 is weakly associated with cognitive function in humans. Our study provides evidence that PGD2-CRTH2 signaling is involved in cognitive function and may represent a potential therapeutic target for cognitive dysfunction in patients with psychiatric disorders.

Topics: Animals; Cognitive Dysfunction; Disease Models, Animal; Dizocilpine Maleate; Male; Mice, Inbred BALB C; Mice, Knockout; Prostaglandin D2; Receptors, Immunologic; Receptors, N-Methyl-D-Aspartate; Receptors, Prostaglandin; Signal Transduction

The kinetic participation of macrophages is critical for inflammatory resolution and recovery from myocardial infarction (MI), particularly with respect to the transition from the M1 to the M2 phenotype; however, the underlying mechanisms are poorly understood. In this study, we found that the deletion of prostaglandin (PG) D2 receptor subtype 1 (DP1) in macrophages retarded M2 polarization, antiinflammatory cytokine production, and resolution in different inflammatory models, including the MI model. DP1 deletion up-regulated proinflammatory genes expression via JAK2/STAT1 signaling in macrophages, whereas its activation facilitated binding of the separated PKA regulatory IIα subunit (PRKAR2A) to the transmembrane domain of IFN-γ receptor, suppressed JAK2-STAT1 axis-mediated M1 polarization, and promoted resolution. PRKAR2A deficiency attenuated DP1 activation-mediated M2 polarization and resolution of inflammation. Collectively, PGD2-DP1 axis-induced M2 polarization facilitates resolution of inflammation through the PRKAR2A-mediated suppression of JAK2/STAT1 signaling. These observations indicate that macrophage DP1 activation represents a promising strategy in the management of inflammation-associated diseases, including post-MI healing.

Topics: Animals; Cecum; Cell Polarity; Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; Disease Models, Animal; Female; Gene Deletion; Hydantoins; Inflammation; Janus Kinase 2; Ligation; Macrophages; Mice, Inbred C57BL; Myocardial Infarction; Myocardial Ischemia; Peritonitis; Prostaglandin D2; Protein Binding; Protein Subunits; Punctures; Receptors, Immunologic; Receptors, Interferon; Receptors, Prostaglandin; Signal Transduction; STAT1 Transcription Factor; Wound Healing; Zymosan

Pulmonary fibrosis is a progressive and fatal lung disease with limited therapeutic options. Although it is well known that lipid mediator prostaglandins are involved in the development of pulmonary fibrosis, the role of prostaglandin D2 (PGD2) remains unknown. Here, we investigated whether genetic disruption of hematopoietic PGD synthase (H-PGDS) affects the bleomycin-induced lung inflammation and pulmonary fibrosis in mouse. Compared with H-PGDS naïve (WT) mice, H-PGDS-deficient mice (H-PGDS-/-) represented increased collagen deposition in lungs 14 days after the bleomycin injection. The enhanced fibrotic response was accompanied by an increased mRNA expression of inflammatory mediators, including tumor necrosis factor-α, monocyte chemoattractant protein-1, and cyclooxygenase-2 on day 3. H-PGDS deficiency also increased vascular permeability on day 3 and infiltration of neutrophils and macrophages in lungs on day 3 and 7. Immunostaining showed that the neutrophils and macrophages expressed H-PGDS, and its mRNA expression was increased on day 3and 7 in WT lungs. These observations suggest that H-PGDS-derived PGD2 plays a protective role in bleomycin-induced lung inflammation and pulmonary fibrosis.

Topics: Animals; Bleomycin; Chemokine CCL2; Collagen; Cyclooxygenase 2; Disease Models, Animal; Gene Knockout Techniques; Intramolecular Oxidoreductases; Isomerases; Lung; Macrophages; Mice; Neutrophil Infiltration; Pneumonia; Prostaglandin D2; Pulmonary Fibrosis; Tumor Necrosis Factor-alpha

Prostaglandin D2 (PGD2) causes cough and levels are increased in asthma suggesting that it may contribute to symptoms. Although the prostaglandin D2 receptor 2 (DP2) is a target for numerous drug discovery programmes little is known about the actions of PGD2 on sensory nerves and cough. We used human and guinea pig bioassays, in vivo electrophysiology and a guinea pig conscious cough model to assess the effect of prostaglandin D2 receptor (DP1), DP2 and thromboxane receptor antagonism on PGD2 responses. PGD2 caused cough in a conscious guinea pig model and an increase in calcium in airway jugular ganglia. Using pharmacology and receptor-deficient mice we showed that the DP1 receptor mediates sensory nerve activation in mouse, guinea pig and human vagal afferents. In vivo, PGD2 and a DP1 receptor agonist, but not a DP2 receptor agonist, activated single airway C-fibres. Interestingly, activation of DP2 inhibited sensory nerve firing to capsaicin in vitro and in vivo. The DP1 receptor could be a therapeutic target for symptoms associated with asthma. Where endogenous PGD2 levels are elevated, loss of DP2 receptor-mediated inhibition of sensory nerves may lead to an increase in vagally associated symptoms and the potential for such adverse effects should be investigated in clinical studies with DP2 antagonists.

Topics: Administration, Inhalation; Animals; Bronchial Hyperreactivity; Bronchial Spasm; Capsaicin; Cells, Cultured; Cough; Disease Models, Animal; DNA-Binding Proteins; Guinea Pigs; Humans; Indoles; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Receptors, Thromboxane; Sensitivity and Specificity; Tissue Culture Techniques; Transcription Factor DP1; Transcription Factors; Vagus Nerve

Obesity has been associated with both changes in adipose tissue lipid metabolism and inflammation. A key class of lipid-derived signalling molecules involved in inflammation are the prostaglandins. In this study, we aimed to determine how obesity affects the levels of prostaglandins within white adipose tissue (WAT) and determine which cells within adipose tissue produce them. To avoid the effects of cellular stress on prostaglandin levels, we developed a multivariate statistical approach in which metabolite concentrations and transcriptomic data were integrated, allowing the assignment of metabolites to cell types.. Eicosanoids were measured by liquid chromatography-tandem mass spectrometry and mRNA levels using real-time PCR. Eicosanoid levels and transcriptomic data were combined using principal component analysis and hierarchical clustering in order to associate metabolites with cell types. Samples were obtained from C57Bl/6 mice aged 16 weeks. We studied the ob/ob genetically obese mouse model and diet-induced obesity model. We extended our results in mice to a cohort of morbidly obese humans undergoing bariatric surgery.. Using our modelling approach, we determined that prostglandin D₂ (PGD₂) in adipose tissue was predominantly produced in macrophages by the haematopoietic isoform of prostaglandin D synthase (H-Pgds). Analysis of sub-fractionated WAT confirmed that H-Pgds was expressed in adipose tissue macrophages (ATMs). Furthermore, H-Pgds expression in ATMs isolated from lean and obese mice was consistent with it affecting macrophage polarisation. Functionally, we demonstrated that H-PGDS-produced PGD₂ polarised macrophages toward an M2, anti-inflammatory state. In line with a potential anti-inflammatory role, we found that H-PGDS expression in ATMs was positively correlated with both peripheral insulin and adipose tissue insulin sensitivity in humans.. In this study, we have developed a method to determine the cellular source of metabolites within an organ and used it to identify a new role for PGD₂ in the control of ATM polarisation.

Topics: Adipogenesis; Adipose Tissue; Animals; Chromatography, Liquid; Diet; Disease Models, Animal; Eicosanoids; Humans; Inflammation; Lipid Metabolism; Macrophages; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Prostaglandin D2

Breast cancer is the major cause of cancer death in women worldwide. The most common site of metastasis is bone. Bone metastases obstruct the normal bone remodeling process and aberrantly enhance osteoclast-mediated bone resorption, which results in osteolytic lesions. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is an endogenous ligand of peroxisome proliferator-activated receptor gamma (PPARγ) that has anti-inflammatory and antitumor activity at micromolar concentrations through PPARγ-dependent and/or PPARγ-independent pathways. We investigated the inhibitory activity of 15d-PGJ2 on the bone loss that is associated with breast cancer bone metastasis and estrogen deficiency caused by cancer treatment. 15d-PGJ2 dose-dependently inhibited viability, migration, invasion, and parathyroid hormone-related protein (PTHrP) production in MDA-MB-231 breast cancer cells. 15d-PGJ2 suppressed receptor activator of nuclear factor kappa-B ligand (RANKL) mRNA levels and normalized osteoprotegerin (OPG) mRNA levels in hFOB1.19 osteoblastic cells treated with culture medium from MDA-MB-231 cells or PTHrP, which decreased the RANKL/OPG ratio. 15d-PGJ2 blocked RANKL-induced osteoclastogenesis and inhibited the formation of resorption pits by decreasing the activities of cathepsin K and matrix metalloproteinases, which are secreted by mature osteoclasts. 15d-PGJ2 exerted its effects on breast cancer and bone cells via PPARγ-independent pathways. In Balb/c nu/nu mice that received an intracardiac injection of MDA-MB-231 cells, subcutaneously injected 15d-PGJ2 substantially decreased metastatic progression, cancer cell-mediated bone destruction in femora, tibiae, and mandibles, and serum PTHrP levels. 15d-PGJ2 prevented the destruction of femoral trabecular structures in estrogen-deprived ICR mice as measured by bone morphometric parameters and serum biochemical data. Therefore, 15d-PGJ2 may be beneficial for the prevention and treatment of breast cancer-associated bone diseases.

Topics: Anilides; Animals; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Survival; Disease Models, Animal; Estrogens; Female; Humans; Male; Mice; Mice, Nude; Osteoclasts; Osteolysis; Osteoprotegerin; Ovariectomy; Parathyroid Hormone-Related Protein; PPAR gamma; Prostaglandin D2; RANK Ligand

Macrophages undergo a transition from pro-inflammatory to healing-associated phenotypes that is critical for efficient wound healing. However, the regulation of this transition during normal and impaired healing remains to be elucidated. In our studies, the switch in macrophage phenotypes during skin wound healing was associated with up-regulation of the peroxisome proliferator-activated receptor (PPAR)γ and its downstream targets, along with increased mitochondrial content. In the setting of diabetes, up-regulation of PPARγ activity was impaired by sustained expression of IL-1β in both mouse and human wounds. In addition, experiments with myeloid-specific PPARγ knockout mice indicated that loss of PPARγ in macrophages is sufficient to prolong wound inflammation and delay healing. Furthermore, PPARγ agonists promoted a healing-associated macrophage phenotype both in vitro and in vivo, even in the diabetic wound environment. Importantly, topical administration of PPARγ agonists improved healing in diabetic mice, suggesting an appealing strategy for down-regulating inflammation and improving the healing of chronic wounds.

Topics: Administration, Cutaneous; Animals; Cells, Cultured; Diabetes Mellitus, Type 1; Disease Models, Animal; Female; Humans; Interleukin-1beta; Leg Ulcer; Macrophages; Male; Mice, Inbred C57BL; Mice, Knockout; Phenotype; PPAR gamma; Prostaglandin D2; Receptors, Interleukin-1 Type I; Rosiglitazone; Skin; Thiazolidinediones; Time Factors; Wound Healing

The 5-lipoxygenase product 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is the most powerful human eosinophil chemoattractant among lipid mediators and could play a major pathophysiological role in eosinophilic diseases such as asthma. Its actions are mediated by the OXE receptor, orthologs of which are found in many species from humans to fish, but not rodents. The unavailability of rodent models to examine the pathophysiological roles of 5-oxo-ETE and the OXE receptor has substantially hampered progress in this area. As an alternative, we have explored the possibility that the cat could serve as an appropriate animal model to investigate the role of 5-oxo-ETE. We found that feline peripheral blood leukocytes synthesize 5-oxo-ETE and that physiologically relevant levels of 5-oxo-ETE are present in bronchoalveolar lavage fluid from cats with experimentally induced asthma. 5-Oxo-ETE (EC50, 0.7nM) is a much more potent activator of actin polymerization in feline eosinophils than various other eicosanoids, including leukotriene (LT) B4 and prostaglandin D2. 5-Oxo-ETE and LTB4 induce feline leukocyte migration to similar extents at low concentrations (1nM), but at higher concentrations the response to 5-oxo-ETE is much greater. Although high concentrations of selective human OXE receptor antagonists blocked 5-oxo-ETE-induced actin polymerization in feline granulocytes, their potencies were about 200 times lower than for human granulocytes. We conclude that feline leukocytes synthesize and respond to 5-oxo-ETE, which could potentially play an important role in feline asthma, a common condition in this species. The cat could serve as a useful animal model to investigate the pathophysiological role of 5-oxo-ETE.

Topics: Actins; Allergens; Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acids; Asthma; Benzeneacetamides; Benzothiazoles; Bronchoalveolar Lavage Fluid; Cats; Chemotaxis; Cynodon; Disease Models, Animal; Eosinophils; Female; Gene Expression; Humans; Leukotriene B4; Male; Neutrophils; Polymerization; Primary Cell Culture; Prostaglandin D2; Receptors, Eicosanoid

The effects of PGD2 are extremely context dependent. It can have pro- or anti-inflammatory effects in clinically important pathological conditions. A greater mechanistic insight into the determinants of PGD2 activity during inflammation is thus required. In this study, we investigated the role of PGD2 in croton oil-induced dermatitis using transgenic (TG) mice overexpressing hematopoietic PGD synthase. Administration of croton oil caused tissue swelling and vascular leakage in the mouse ear. Compared with wild-type animals, TG mice produced more PGD2 and showed decreased inflammation in the early phase, but more severe manifestations during the late phase. Data obtained from bone marrow transplantation between wild-type and TG mice indicated that PGD2 produced by tissue resident cells in the TG mice attenuated early-phase inflammation, whereas PGD2 produced from hematopoietic lineage cells exacerbated late-phase inflammation. There are two distinct PGD2 receptors: D-prostanoid receptor (DP) and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). In TG mice, treatment with a DP antagonist exacerbated inflammation in the early phase, whereas treatment with a CRTH2 antagonist attenuated inflammation during the late phase. In vitro experiments showed that DP agonism enhanced vascular endothelial barrier formation, whereas CRTH2 agonism stimulated neutrophil migration. Collectively, these results show that when hematopoietic PGD synthase is overexpressed, tissue resident cell-derived PGD2 suppresses skin inflammation via DP in the early phase, but hematopoietic lineage cell-derived PGD2 stimulates CRTH2 and promotes inflammation during the late phase. DP-mediated vascular barrier enhancement or CRTH2-mediated neutrophil activation may be responsible for these effects. Thus, PGD2 represents opposite roles in inflammation, depending on the disease phase in vivo.

Topics: Animals; Capillary Permeability; Chemotaxis, Leukocyte; Dermatitis; Disease Models, Animal; Disease Progression; Gene Expression; Immunologic Factors; Intramolecular Oxidoreductases; Leukocytes; Lipocalins; Mice; Neutrophils; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Signal Transduction

Aspergillus fumigatus is often associated in asthmatic patients with the exacerbation of asthma symptoms. The pathomechanism of this phenomenon has not been fully understood. Here, we evaluated the immunological mechanisms and the role of the prostaglandin D2 / Chemoattractant Receptor-Homologous Molecule Expressed on Th2 Cells (CRTH2) pathway in the development of Aspergillus-associated asthma exacerbation. We studied the effects of A. fumigatus on airway inflammation and bronchial hyper-responsiveness in a rat model of chronic asthma. Inhalation delivery of A. fumigatus conidia increased the airway eosinophilia and bronchial hyper-responsiveness in ovalbumin-sensitized, challenged rats. These changes were associated with prostaglandin D2 synthesis and CRTH2 expression in the lungs. Direct inflammation occurred in ovalbumin-sensitized, challenged animals, whereas pre-treatment with an antagonist against CRTH2 nearly completely eliminated the A. fumigatus-induced worsening of airway eosinophilia and bronchial hyper-responsiveness. Our data demonstrate that production of prostaglandin D2 followed by eosinophil recruitment into the airways via a CRTH2 receptor are the major pathogenic factors responsible for the A. fumigatus-induced enhancement of airway inflammation and responsiveness.

Topics: Animals; Anti-Inflammatory Agents; Aspergillus fumigatus; Asthma; Bronchial Hyperreactivity; Disease Models, Animal; Eosinophils; Lung; Male; Ovalbumin; Prostaglandin D2; Pulmonary Aspergillosis; Pulmonary Eosinophilia; Rats; Rats, Wistar; Receptors, Immunologic; Receptors, Prostaglandin; Signal Transduction

Prostaglandin D2 (PGD2 ) plays an important role in allergic inflammation. The PGD2 receptor, CRTH2, is expressed on basophils, eosinophils, and Th2 lymphocytes and mediates chemotactic activity.. To define the role of CRTH2 in allergen-induced nasal responses in a mouse model of allergic rhinitis (AR), a potent, selective CRTH2 receptor antagonist, ARRY-063 was administered in a model of allergic rhinitis in mice.. ARRY-063 was administered orally to ovalbumin (OVA) sensitized and challenged mice. To assess nasal obstruction, respiratory frequency (RF) was monitored by whole-body plethysmography immediately after the 4th challenge (early-phase response, EPR) and 24 h after the 6th challenge (late-phase response, LPR). Nasal resistance (RNA ) was also measured in the LPR. PGD2 was administered with or without OVA to determine the effect of PGD2 on nasal responsiveness. Cytokine levels and histopathological changes in nasal tissue were analysed.. Instillation of PGD2 in the nose of sensitized mice together with a low concentration of OVA induced both an EPR and LPR. Treatment with the CRTH2 receptor antagonist prevented the decreases in RF seen immediately following the 4th challenge of sensitized mice (EPR). In the LPR, decreases in RF and increases in RNA were also prevented by antagonist treatment associated with reduced cytokine levels and inflammation in nasal tissues.. These data identify PGD2 as a mediator of both the EPR and LPR in this model of AR and suggest that antagonism of CRTH2 prevents the development of both the EPR and LPR as well as nasal inflammation.

Topics: Allergens; Animals; Disease Models, Animal; Eosinophils; Female; Mice; Nasal Mucosa; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Rhinitis, Allergic

Biyeom-Tang, a medicine prescribed by oriental clinics, has been used for the treatment of the allergic rhinitis (AR). In the present study, an ethanol extract of Biyeom-Tang (EBT) was investigated for anti-allergic properties on bone-marrow derived mast cells (BMMC) and in vivo models.. The anti-allergic properties of EBT were evaluated by measuring β-Hex release and the production of prostaglandin D2 (PGD2) and leukotriene C4 (LTC4) on BMMC in vitro and PCA and OVA-induced AR models in vivo.. EBT strongly inhibited a degranulation reaction in a dose dependent manner with an IC50 value of 35.6 μg/ml. In addition, the generation of PGD2 and LTC4 was inhibited in BMMC in a concentration-dependent manner with IC50 values of 7.0 μg/ml and 10.9 μg/ml, respectively. When administrated orally, EBT ameliorated the mast cell-mediated PCA reaction. In the OVA-induced AR model, the increased levels of IgE were reduced by EBT. The levels of cytokines, such as IL-4, IL-5, IL-10, and IL-13 decreased in the splenocytes of EBT-treated mice. The histological analysis shows that the infiltration of inflammatory cells increased by OVA-sensitization was also reduced.. Taken together, these results suggested that EBT has anti-allergic and anti-inflammatory effects in vitro and in vivo models.

Topics: Angelica; Animals; Anti-Allergic Agents; Anti-Inflammatory Agents; Bone Marrow Cells; Disease Models, Animal; Female; Immunoglobulin E; Interleukins; Male; Mast Cells; Medicine, Korean Traditional; Mentha; Mice, Inbred BALB C; Mice, Inbred ICR; Phytotherapy; Plant Extracts; Prostaglandin D2; Rhinitis, Allergic; Trichosanthes; Xanthium

Neuroinflammation is a major risk factor in Parkinson's disease (PD). Alternative approaches are needed to treat inflammation, as anti-inflammatory drugs such as NSAIDs that inhibit cyclooxygenase-2 (COX-2) can produce devastating side effects, including heart attack and stroke. New therapeutic strategies that target factors downstream of COX-2, such as prostaglandin J2 (PGJ2), hold tremendous promise because they will not alter the homeostatic balance offered by COX-2 derived prostanoids. In the current studies, we report that repeated microinfusion of PGJ2 into the substantia nigra of non-transgenic mice, induces three stages of pathology that mimic the slow-onset cellular and behavioral pathology of PD: mild (one injection) when only motor deficits are detectable, intermediate (two injections) when neuronal and motor deficits as well as microglia activation are detectable, and severe (four injections) when dopaminergic neuronal loss is massive accompanied by microglia activation and motor deficits. Microglia activation was evaluated in vivo by positron emission tomography (PET) with [(11)C](R)PK11195 to provide a regional estimation of brain inflammation. PACAP27 reduced dopaminergic neuronal loss and motor deficits induced by PGJ2, without preventing microglia activation. The latter could be problematic in that persistent microglia activation can exert long-term deleterious effects on neurons and behavior. In conclusion, this PGJ2-induced mouse model that mimics in part chronic inflammation, exhibits slow-onset PD-like pathology and is optimal for testing diagnostic tools such as PET, as well as therapies designed to target the integrated signaling across neurons and microglia, to fully benefit patients with PD.

Topics: Animals; Antineoplastic Agents; Behavior, Animal; Disease Models, Animal; Encephalitis; Immunoenzyme Techniques; Male; Mice; Microglia; Motor Skills Disorders; Neurons; Parkinson Disease; Pituitary Adenylate Cyclase-Activating Polypeptide; Positron-Emission Tomography; Prostaglandin D2

Prostaglandin J₂ (PGJ₂) is neuroprotective in a murine model of nonarteritic anterior ischemic optic neuropathy (NAION). After assessing for potential toxicity, we evaluated the efficacy of a single intravitreal (IVT) injection of PGJ₂ in a nonhuman primate model of NAION (pNAION).. We assessed PGJ₂ toxicity by administering it as a single high-dose intravenous (IV) injection, consecutive daily high-dose IV injections, or a single IVT injection in one eye of five adult rhesus monkeys. To assess efficacy, we induced pNAION in one eye of five adult male rhesus monkeys using a laser-activated rose bengal induction method. We then injected the eye with either PGJ₂ or phosphate-buffered saline (PBS) intravitreally immediately or 5 hours post induction. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in all animals prior to induction and at 1 day, 1 week, 2 weeks, and 4 weeks after induction. Following analysis of the first eye, we induced pNAION in the contralateral eye and then injected either PGJ₂ or PBS. We euthanized all animals 5 weeks after final assessment of the fellow eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves.. PGJ₂ caused no permanent systemic toxicity regardless of the amount injected or route of delivery, and there was no evidence of any ocular toxicity with the dose of PGJ₂ used in efficacy studies. Transient reduction in the amplitudes of the visual evoked potentials and the N95 component of the pattern electroretinogram (PERG) occurred after both IV and IVT administration of high doses of PGJ₂; however, the amplitudes returned to normal in all animals within 1 week.. In all eyes, a single IVT dose of PGJ₂ administered immediately or shortly after induction of pNAION resulted in a significant reduction of clinical, electrophysiological, and histological damage compared with vehicle-injected eyes (P = 0.03 for both VEP and PERG; P = 0.05 for axon counts).. In nonhuman primates, PGJ₂ administered either intravenously or intravitreally produces no permanent toxicity at even four times the dose given for neuroprotection. Additionally, a single IVT dose of PGJ₂ is neuroprotective when administered up to 5 hours after induction of pNAION.

Topics: Animals; Antineoplastic Agents; Delayed-Action Preparations; Disease Models, Animal; Evoked Potentials, Visual; Fluorescein Angiography; Follow-Up Studies; Fundus Oculi; Intravitreal Injections; Male; Optic Nerve; Optic Neuropathy, Ischemic; Prostaglandin D2; Prostaglandins, Synthetic; Rats; Rats, Long-Evans; Retinal Ganglion Cells; Tomography, Optical Coherence

Cyclosporine A(CsA) is an immunosuppressor frequently used in the transplant surgery and in the treatment of autoimmune diseases. The therapeutic benefits of CsA are often limited by it's main side effect-nephrotoxicity. Mechanisms of chronic CsA- induced renal damage include: activation of renin-angiotensin-aldosterone system, upregulation of transforming growth factor beta (TGF-β), oxidative stress. This study was undertaken to investigate the protective effect of the peroxisome-proliferator-activated receptors gamma (PPARs-γ) agonists: rosiglitazone and 15-deoxy-Δ12,14-prostaglandin J2 (PGDJ2), against CsA-induced kidney injury in male Wistar rats. CsA was administered subcutaneously at a dose of 15 mg/kg/day for 28 days. Both PPAR-γ agonists were given for 28 days 0.5 hour before the administration of CsA. Rosiglitazone was administered orally at a dose of 8 mg/kg/day and PGDJ2 was given intraperitoneally at a dose of 30 μg/kg/day. CsA induced renal failure was evidenced by increased serum levels of urea, uric acid and creatinine. Serum concentrations of GSH and GSSG, lipid peroxidation products as well as NAD+/NADH, NADP+/NADPH and ADP/ATP ratios showed, that CsA induced oxidative stress and evoked an imbalanced red-ox state in the kidney. Light and electron microscope studies showed degenerative changes within renal tubules with damage to their mitochondria, interstitial fibrosis and arteriolopathy. Immunohistochemical expression of profibrotic TGF-β was assessed. The biochemical and morphological changes induced by CsA were limited by administration of both rosiglitazone and PGDJ2. Ultrastructural examination of renal tubular epithelial cells showed marked improvement within mitochondria. Our results indicate that both PPAR-γ agonists used in the experiment may play an important role in protecting against CsA-induced damage in the kidney.

Topics: Animals; Creatinine; Cyclosporine; Disease Models, Animal; Glutathione; Glutathione Disulfide; Kidney; Kidney Diseases; Male; NAD; NADP; PPAR gamma; Prostaglandin D2; Protective Agents; Rats, Wistar; Rosiglitazone; Thiazolidinediones; Urea; Uric Acid

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common cause of sudden optic nerve-related vision loss in persons older than 50 in the United States. There currently is no treatment for this disorder. We previously showed that systemic administration of 15-deoxy, delta (12, 14) prostaglandin J2 (PGJ2) is neuroprotective in our rodent model of AION (rAION). In this study, we determined if a single intravitreal (IVT) injection of PGJ2 is neuroprotective after rAION, and if this method of administration is toxic to the retina, optic nerve, or both.. TOXICITY was assessed after a single IVT injection of PGJ2 in one eye and PBS in the contralateral eye of normal, adult Long-Evans rats. EFFICACY was assessed by inducing rAION in one eye and injecting either PGJ2 or vehicle immediately following induction, with the fellow eye serving as naïve control. Visual evoked potentials (VEPs) and ERGs were performed before induction and at specific intervals thereafter. Animals were euthanized 30 days after induction, after which immunohistochemistry, transmission electron microscopy, and quantitative stereology of retinal ganglion cell (RGC) numbers were performed.. IVT PGJ2 did not alter the VEP or ERG compared with PBS-injected control eyes, and neither IVT PGJ2 nor PBS reduced overall RGC numbers.. IVT PGJ2 preserved VEP amplitude, reduced optic nerve edema, and resulted in significant preservation of RGCs and axons in eyes with rAION.. A single IVT injection of PGJ2 is nontoxic to the retina and optic nerve and neuroprotective when given immediately after rAION induction.

Topics: Animals; Disease Models, Animal; Electroretinography; Evoked Potentials, Visual; Intravitreal Injections; Neuroprotective Agents; Optic Neuropathy, Ischemic; Prostaglandin D2; Rats; Rats, Long-Evans; Retinal Ganglion Cells

Phospholipases A2 (PLA2) hydrolyzes phospholipids, initiating the production of inflammatory lipid mediators. We have previously shown that in rats, sPLA2 and cPLA2 play opposing roles in the pathophysiology of ovalbumin (OVA)-induced experimental allergic bronchitis (OVA-EAB), an asthma model: Upon disease induction sPLA2 expression and production of the broncho-constricting CysLTs are elevated, whereas cPLA2 expression and the broncho-dilating PGE2 production are suppressed. These were reversed upon disease amelioration by treatment with an sPLA2 inhibitor. However, studies in mice reported the involvement of both sPLA2 and cPLA2 in EAB induction.. To examine the relevance of mouse and rat models to understanding asthma pathophysiology.. OVA-EAB was induced in mice using the same methodology applied in rats. Disease and biochemical markers in mice were compared with those in rats.. As in rats, EAB in mice was associated with increased mRNA of sPLA2, specifically sPLA2gX, in the lungs, and production of the broncho-constricting eicosanoids CysLTs, PGD2 and TBX2 in bronchoalveolar lavage (BAL). In contrast, EAB in mice was associated also with elevated cPLA2 mRNA and PGE2 production. Yet, treatment with an sPLA2 inhibitor ameliorated the EAB concomitantly with reverting the expression of both cPLA2 and sPLA2, and eicosanoid production.. In both mice and rats sPLA2 is pivotal in OVA-induced EAB. Yet, amelioration of asthma markers in mouse models, and human tissues, was observed also upon cPLA2 inhibition. It is plausible that airway conditions, involving multiple cell types and organs, require the combined action of more than one, essential, PLA2s.

Topics: Animals; Arachidonate 5-Lipoxygenase; Arginase; Asthma; Blotting, Western; Bronchitis; Bronchoalveolar Lavage Fluid; Chitinases; Cysteine; Dinoprostone; Disease Models, Animal; Female; Group X Phospholipases A2; Humans; Leukotrienes; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Phospholipases A2, Cytosolic; Phospholipases A2, Secretory; Prostaglandin D2; Rats; Receptors, Leukotriene; Reverse Transcriptase Polymerase Chain Reaction; T-Box Domain Proteins

We have previously shown nutritional intervention with fish oil (n-3 PUFA) to reduce numerous complications associated with the metabolic syndrome (MetS) in the JCR:LA-corpulent (cp) rat. In the present study, we sought to explore the potential role of fish oil to prevent glomerulosclerosis in JCR:LA-cp rats via renal eicosanoid metabolism and lipidomic analysis. Male lean and MetS JCR:LA-cp rats were fed a lipid-balanced diet supplemented with fish oil (5 or 10 % of total fat). After 16 weeks of feeding, albuminuria was significantly reduced in MetS rats supplemented with 5 or 10 % fish oil ( - 53 and - 70 %, respectively, compared with the untreated MetS rats). The 5 % fish oil diet resulted in markedly lower glomerulosclerosis ( - 43 %) in MetS rats and to a lesser extent in those supplemented with 10 % fish oil. Interestingly, untreated MetS rats had higher levels of 11- and 12-hydroxyeicosatetraenoic acids (HETE) v. lean rats. Dietary fish oil reduced these levels, as well as other (5-, 9- and 15-) HETE. Whilst genotype did not alter prostanoid levels, fish oil reduced endogenous renal levels of 6-keto PGF1α (PGI2 metabolite), thromboxane B2 (TxB2), PGF2α and PGD2 by approximately 60 % in rats fed 10 % fish oil, and TxB2 ( - 50 %) and PGF2α ( - 41 %) in rats fed 5 % fish oil. In conclusion, dietary fish oil prevented glomerular damage in MetS rats and mitigated the elevation in renal HETE levels. These results suggest a potential role for dietary fish oil to improve dysfunctional renal eicosanoid metabolism associated with kidney damage during conditions of the MetS.

Topics: 6-Ketoprostaglandin F1 alpha; Albuminuria; Animals; Dietary Fats; Dietary Supplements; Dinoprost; Disease Models, Animal; Fish Oils; Genotype; Hydroxyeicosatetraenoic Acids; Kidney Diseases; Kidney Glomerulus; Male; Metabolic Syndrome; Prostaglandin D2; Prostaglandins; Rats; Rats, Inbred Strains; Thromboxane B2

Tumor-associated inflammation is a driving force in several adult cancers and intake of low-dose aspirin has proven to reduce cancer incidence. Little is known about tumor-associated inflammation in pediatric neoplasms and no in vivo data exists on the effectiveness of low-dose aspirin on established tumors. The present study employs the transgenic TH-MYCN mouse model for neuroblastoma (NB) to evaluate inflammatory patterns paralleling tumor growth in vivo and low-dose aspirin as a therapeutic option for high-risk NB. Spontaneously arising abdominal tumors were monitored for tumor-associated inflammation ex vivo at various stages of disease and homozygous mice received daily low-dose aspirin (10mg/kg) using oral gavage or no treatment, from 4.5 to 6 weeks of age. Using flow cytometry, a transition from an adaptive immune response predominated by CD8(+) T cell in early neoplastic lesions, towards enrichment in immature cells of the innate immune system, including myeloid-derived suppressor cells, dendritic cells and tumor-associated macrophages, was detected during tumor progression. An M1 to M2 transition of tumor-associated macrophages was demonstrated, paralleled by a deterioration of dendritic cell status. Treatment with low-dose aspirin to mice homozygous for the TH-MYCN transgene significantly reduced the tumor burden (P < 0.01), the presence of tumor-associated cells of the innate immune system (P < 0.01), as well as the intratumoral expression of transforming growth factor-β, thromboxane A2 (P < 0.05) and prostaglandin D2 (P < 0.01). In conclusion, tumor-associated inflammation appears as a potential therapeutic target in NB and low-dose aspirin reduces tumor burden in the TH-MYCN transgenic mouse model of NB, hence warranting further studies on aspirin in high-risk NB.

Topics: Animals; Aspirin; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cytokines; Dendritic Cells; Disease Models, Animal; Disease Progression; Homozygote; Immunity, Innate; Inflammation; Macrophages; Mice; Mice, Transgenic; Neuroblastoma; Prostaglandin D2; Th2 Cells; Thromboxane A2; Transforming Growth Factor beta

Peroxisome proliferator-activated receptor-γ (PPAR-γ) has recently emerged as potential therapeutic agents for cerebral ischemia-reperfusion (I/R) injury because of anti-neuronal apoptotic actions. However, whether PPAR-γ activation mediates neuronal autophagy in such conditions remains unclear. Therefore, in this study, we investigated the role of PPAR-γ agonist 15-PGJ(2) on neuronal autophagy induced by I/R. The expression of autophagic-related protein in ischemic cortex such as LC3-II, Beclin 1, cathepsin-B and LAMP1 increased significantly after cerebral I/R injury. Furthermore, increased punctate LC3 labeling and cathepsin-B staining occurred in neurons. Treatment with PPAR-γ agonist 15d-PGJ(2) decreased not only autophagic-related protein expression in ischemic cortex, but also immunoreactivity of LC3 and cathepsin-B in neurons. Autophagic inhibitor 3-methyladenine (3-MA) decreased LC3-II levels, reduced the infarct volume, and mimicked some protective effect of 15d-PGJ(2) against cerebral I/R injury. These results indicate that PPAR-γ agonist 15d-PGJ(2) exerts neuroprotection by inhibiting neuronal autophagy after cerebral I/R injury. Although the molecular mechanisms underlying PPAR-γ agonist in mediating neuronal autophagy remain to be determined, neuronal autophagy may be a new target for PPAR-γ agonist treatment in cerebral I/R injury.

Topics: Animals; Autophagy; Brain Ischemia; Cathepsin B; Disease Models, Animal; Humans; Male; Mice; Microtubule-Associated Proteins; Neurons; Neuroprotective Agents; PPAR gamma; Prostaglandin D2; Reperfusion Injury

We have previously demonstrated that the anti-inflammatory prostaglandin 15-deoxy-Δ 12,14-prostaglandin J(2) (15dPGJ(2)) delays inflammation-induced preterm labour in the mouse and improves pup survival through the inhibition of nuclear factor-κB (NF-κB) by a mechanism yet to be elucidated. 15dPGJ(2) is an agonist of the second prostaglandin D(2) receptor, chemoattractant receptor homologous to the T helper 2 cell (CRTH2). In human T helper cells CRTH2 agonists induce the production of the anti-inflammatory interleukins IL-10 and IL-4. We hypothesized that CRTH2 is involved in the protective effect of 15dPGJ(2) in inflammation-induced preterm labour in the murine model. We therefore studied the effects of a specific small molecule CRTH2 agonist on preterm labour and pup survival. An intrauterine injection of lipopolysaccharide (LPS) was administered to CD1 mice at embryonic day 16, ± CRTH2 agonist/vehicle controls. Mice were killed at 4.5 hr to assess fetal wellbeing and to harvest myometrium and pup brain for analysis of NF-κB, and T helper type 1/2 interleukins. To examine the effects of the CRTH2 agonist on LPS-induced preterm labour, mice were allowed to labour spontaneously. Direct effects of the CRTH2 agonist on uterine contractility were examined ex vivo on contracting myometrial strips. The CRTH2 agonist increased fetal survival from 20 to 100% in LPS-treated mice, and inhibited circular muscle contractility ex vivo. However, it augmented LPS-induced labour and significantly increased myometrial NF-κB, IL-1β, KC-GRO, interferon-γ and tumour necrosis factor-α. This suggests that the action of 15dPGJ(2) is not via CRTH2 and therefore small molecule CRTH2 agonists are not likely to be beneficial for the prevention of inflammation-induced preterm labour.

Topics: Animals; Anti-Inflammatory Agents; Brain; Cytokines; Disease Models, Animal; Female; Fetal Death; Humans; Immunologic Factors; Inflammation; Lipopolysaccharides; Mice; Myometrium; Obstetric Labor, Premature; Peptides; Pregnancy; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin

We evaluate the immunomodulation of Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists 15d-PGJ(2) and rosiglitazone (RGZ) in a model of chronic eosinophilia. 15d-PGJ(2) and RGZ significantly reduce eosinophil migration into the peritoneal cavity and down-regulate the eosinopoiesis. The synthesis of IL-5 was decreased after the treatment with 15d-PGJ(2) and RGZ corroborating with the eosinophil migration inhibition. However, IgE was decreased only after the administration of 15d-PGJ(2) in part due to B-cell inhibition. We also observed a decrease in the synthesis of IL-33, IL-17 and IL-23, suggesting that besides the modulation of Th2 pattern, there is a modulation via IL-23 and IL-17 suggesting a role of these cytokines in the eosinophil recruitment. In fact IL-17(-/-) mice failed to develop an eosinophilic response. Altogether, the results showed that PPAR-γ agonists mainly 15d-PGJ(2), have therapeutic efficacy in eosinophil-induced diseases with an alternative mechanism of control, via IL-23/IL-17 and IL-33.

Topics: Allergens; Animals; Cell Movement; Cell Proliferation; Disease Models, Animal; Eosinophilia; Eosinophils; Flow Cytometry; Immunoglobulin E; Inflammation; Interleukins; Leukocyte Count; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; PPAR gamma; Prostaglandin D2; Rosiglitazone; Thiazolidinediones

15-Deoxy-Δ(12,14) -Prostaglandin J(2) (15d-PGJ(2) ), a natural peroxisome proliferator-activated receptor gamma (PPAR-γ) ligand, has been implicated as a new antiinflammatory compound with possible clinical applications. Based on this concept, this study was designed to evaluate the effects of 15d-PGJ(2) on bone marrow-derived monocyte/macrophage (BMM) migration, phagocytosis, and cytokine expression after liver injury using mouse models induced by cholestasis or carbon tetrachloride. Mice were lethally irradiated and received bone marrow transplants from enhanced green fluorescent protein transgenic mice. Our results showed that recruitment of BMM was significantly increased during chronic liver injury, and that 15d-PGJ(2) administration reduced BMM, but not neutrophil, dendritic, or T cell migration toward the damaged liver, involving reactive oxygen species generation and independently of PPAR-γ. Moreover, 15d-PGJ(2) inhibited the phagocytic activity of BMM and down-regulated inflammatory cytokine expression in vivo and in vitro. Accordingly, hepatic inflammation and fibrosis were strikingly ameliorated after 15d-PGJ(2) administration.. Our findings strongly suggest the antiinflammation and antifibrogenic potential of 15d-PGJ(2) in chronic liver diseases.

Topics: Analysis of Variance; Animals; Bone Marrow Transplantation; Cell Movement; Cell Proliferation; Cells, Cultured; Chronic Disease; Disease Models, Animal; Flow Cytometry; Fluorescent Antibody Technique; Liver Cirrhosis; Macrophages; Mice; Mice, Transgenic; Phagocytosis; Prostaglandin D2; Random Allocation; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction

Allergic rhinitis is the most common allergic disease, displaying the typical nasal symptom of congestion. Prostaglandin D(2) (PGD(2)), a chemical mediator released in large amounts by mast cells upon allergic stimulation in humans, is known to be involved in nasal congestion. However, the mechanism by which this congestion occurs remains unclear.. The effect of PGD(2) on the nasal airflow in guinea pigs was measured using a noninvasive approach that avoided any anesthetic effect. Isometric tension of isolated nasal mucosa and the nasal vascular corrosion resin cast technique were used to clarify the area of nasal mucosal vessels affected by PGD(2), and to examine the mechanism of PGD(2)-induced nasal congestion. Moreover, the involvement of second messengers in PGD(2)-induced mucosal relaxation was investigated.. PGD(2) induced an increase in intranasal pressure in a guinea pig model of rhinitis. Additionally, sinusoidal microvessel dilatation appeared around the septum using the vascular corrosion resin cast technique in the nasal mucosa. Moreover, relaxation of the nasal mucosa following stimulation of the prostanoid DP-1 receptor was associated with cAMP levels in the tissue.. PGD(2)-induced nasal congestion is caused by direct dilatation of the sinusoid vessels through the increase of cAMP levels in the nasal mucosa, demonstrating that the mechanism of PGD(2)-induced nasal congestion is different from other chemical mediators. Consequently, antagonists for the prostanoid DP-1 receptor would be an alternative approach for the relief of nasal congestion. Alternatively, the combined administration with antagonists for other mediators involved in nasal congestion may also be a valuable therapy for allergic rhinitis.

Topics: Animals; Cyclic AMP; Disease Models, Animal; Guinea Pigs; Male; Nasal Mucosa; Nasal Obstruction; Prostaglandin D2; Receptors, Prostaglandin; Rhinitis, Allergic, Perennial

The use of niacin in the treatment of dyslipidemias is limited by the common side effect of cutaneous vasodilation, commonly termed flushing. Flushing is thought to be due to release of the vasodilatory prostanoids prostaglandin D2 (PGD2) and prostaglandin E2 from arachidonic acid metabolism through the cyclooxygenase pathway. Arachidonic acid is also metabolized by the cytochrome P450 system, which is regulated, in part, by the enzyme soluble epoxide hydrolase (sEH).. These experiments used an established murine model in which ear tissue perfusion was measured by laser Doppler to test the hypothesis that inhibition of sEH would limit niacin-induced flushing.. Niacin-induced flushing was reduced from 506 ± 126% to 213 ± 39% in sEH knockout animals. Pharmacologic treatment with 3 structurally distinct sEH inhibitors similarly reduced flushing in a dose-dependent manner, with maximal reduction to 143% ± 15% of baseline flow using a concentration of 1 mg/kg TPAU (1-trifluoromethoxyphenyl-3-(1-acetylpiperidin-4-yl) urea). Systemically administered PGD2 caused ear vasodilation, which was not changed by either pharmacologic sEH inhibition or sEH gene deletion.. Inhibition of sEH markedly reduces niacin-induced flushing in this model without an apparent effect on the response to PGD2. sEH inhibition may be a new therapeutic approach to limit flushing in humans.

Topics: Animals; Arachidonic Acid; Dinoprostone; Disease Models, Animal; Dose-Response Relationship, Drug; Epoxide Hydrolases; Flushing; Gene Deletion; Laser-Doppler Flowmetry; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Niacin; Phenylurea Compounds; Piperidines; Prostaglandin D2; Vasodilation; Vasodilator Agents

The 15-deoxy-(Δ12,14)-PG J(2) (15d-PGJ(2)) has demonstrated excellent anti-inflammatory results in different experimental models. It can be used with a polymeric nanostructure system for modified drug release, which can change the therapeutic properties of the active principle, leading to increased stability and slower/prolonged release. The aim of the current study was to test a nanotechnological formulation as a carrier for 15d-PGJ(2), and to investigate the immunomodulatory effects of this formulation in a mouse periodontitis model. Poly (D,L-lactide-coglycolide) nanocapsules (NC) were used to encapsulate 15d-PGJ(2). BALB/c mice were infected on days 0, 2, and 4 with Aggregatibacter actinomycetemcomitans and divided into groups (n = 5) that were treated daily during 15 d with 1, 3, or 10 μg/kg 15d-PGJ(2)-NC. The animals were sacrificed, the submandibular lymph nodes were removed for FACS analysis, and the jaws were analyzed for bone resorption by morphometry. Immunoinflammatory markers in the gingival tissue were analyzed by reverse transcriptase-quantitative PCR, Western blotting, or ELISA. Infected animals treated with the 15d-PGJ(2)-NC presented lower bone resorption than infected animals without treatment (p < 0.05). Furthermore, infected animals treated with 10 μg/kg 15d-PGJ(2)-NC had a reduction of CD4(+)CD25(+)FOXP3(+) cells and CD4/CD8 ratio in the submandibular lymph node (p < 0.05). Moreover, CD55 was upregulated, whereas RANKL was downregulated in the gingival tissue of the 10 μg/kg treated group (p < 0.05). Several proinflammatory cytokines were decreased in the group treated with 10 μg/kg 15d-PGJ(2)-NC, and high amounts of 15d-PGJ(2) were observed in the gingiva. In conclusion, the 15d-PGJ(2)-NC formulation presented immunomodulatory effects, decreasing bone resorption and inflammatory responses in a periodontitis mouse model.

Topics: Actinobacillus Infections; Aggregatibacter actinomycetemcomitans; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bone Resorption; Disease Models, Animal; Gingiva; Mice; Mice, Inbred BALB C; Mice, Inbred DBA; Nanocapsules; Periodontitis; Prostaglandin D2

The objective of the present study is to elucidate the pathogenic role of eicosanoids in myocardial infarction (MI). The accumulation of eicosanoid metabolites in ischaemic myocardium has been demonstrated in animal models and patients with MI, and it occurs in parallel with the development of irreversible cardiac damage. However, the key question that remains unanswered is whether cardiac-generated eicosanoids are the cause or the consequence of cardiac cell damage in MI.. We used a clinically relevant animal model of MI and metabolic profiling to monitor the eicosanoid profile in ischaemic myocardium. We demonstrate that ischaemia induces the generation of prostanoids mainly through the cyclooxygenase (COX)-1 pathway in the myocardium. Cardiac-generated prostanoids, particularly prostaglandin D(2) (PGD(2)), can directly induce apoptosis in cardiac myocytes. This effect involves the up-regulation of the pro-apoptotic gene, Fas ligand (FasL), in a D-type prostanoid receptor-independent manner. The treatment of the MI mice with low-dose aspirin effectively inhibits the ischaemia-induced prostanoid generation and FasL expression in the myocardium, leading to the reduction in cardiac apoptosis following cardiac ischaemia.. Cardiac ischaemia results in COX-1-mediated generation of prostanoids, which by inducing cardiac myocyte apoptosis, contribute to the cardiac cell loss following MI. The benefits of low-dose aspirin treatment in MI may be attributable, in part, to the inhibition of cardiac prostanoid generation and attenuation of apoptosis. Further understanding of the mechanisms underlying prostanoid-induced cardiac apoptosis may be of significant value in designing new therapeutic strategies to prevent aberrant cell loss following MI and subsequent progression to heart failure.

Topics: Animals; Animals, Newborn; Apoptosis; Aspirin; Cells, Cultured; Cyclooxygenase 1; Cyclooxygenase Inhibitors; Disease Models, Animal; Fas Ligand Protein; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Myocardial Ischemia; Myocardium; Prostaglandin D2; Prostaglandins; Receptors, Immunologic; Receptors, Prostaglandin; RNA, Messenger; Time Factors; Up-Regulation; Ventricular Function, Left

To detect the changes of leukotriene E4(LTE4), prostaglandin D2(PGD2), carboxypeptidase A3(CPA3) and platelet activating factor (PAF) in guinea pigs died from anaphylactic shock.. Guinea pigs were used for establishing anaphylactic shock models. The levels of LTE4, PGD2 and CPA3, and PAF were detected in urine, plasma, and brain tissues with ELISA kit, respectively. The significant biomarkers were selected comparing with control group. The changes of PGD2, CPA3 and PAF in the guinea pigs at time zero, 12 and 24 hours after death were observed and compared respectively. The effect of platelet activating factor acetylhydrolase (PAF-AH) to PAF in guinea pig brain was examined and compared.. There were no statistically differences of LTE4 levels in urine observed between experimental group and control group. The levels of CPA3, PGD2 and PAF in the experimental group were significantly higher than that in the control group at 0 h. The levels of PAF at 12 and 24 hours after anaphylactic shock were significantly higher than that in the control group. The levels of PAF decreased significantly after pretreatment with PAF-AH.. LTE4 in urine cannot be selected as a biomarker to determine the anaphylactic shock. PGD2 and CPA3 in plasma, and PAF in brain tissue may be used as biomarkers to determine the anaphylactic shock. PAF-AH may be potentially useful for clinical treatment of anaphylactic shock.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Anaphylaxis; Animals; Brain; Carboxypeptidases; Case-Control Studies; Disease Models, Animal; Egg Proteins; Enzyme-Linked Immunosorbent Assay; Female; Guinea Pigs; Leukotriene E4; Male; Mice; Platelet Activating Factor; Prostaglandin D2; Time Factors

To investigate the expression level of prostaglandins (PGs) and their de novo synthesis in dry eye (DE) disease.. Cross-sectional case-control study and in vivo mouse experimental study.. Forty-six eyes from 23 DE patients and 33 eyes from 17 age- and sex-matched controls were studied. Also, DE-induced murine eyes were compared with control eyes.. Patients completed a symptom questionnaire using a 100-mm visual analog scale (VAS). Nano-liquid chromatography tandem mass spectrometry was used for the quantification of PGE2 and PGD2. A DE disease environmental chamber was used to induce DE in mice. One week after induction, enzyme expressions of cyclooxygenase-1, cyclooxygenase-2 (COX-2), PG E synthase (PGES), and PG D synthase (PGDS) in the lacrimal glands, meibomian glands, and corneas were examined using immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR).. The mean PGE2 and PGD2 levels in the tears of DE patients were measured and compared with symptom severity scores. Immunohistochemistry staining patterns and qRT-PCR data of DE mice were quantified.. The mean PGE2 level in the tears of DE patients (2.72 ±3 .42 ng/ml) was significantly higher than that in the control group (0.88 ± 0.83 ng/ml; P = 0.003). However, the mean PGD2 level in the tears of DE patients (0.11 ± 0.22 ng/ml) was significantly lower (0.91 ± 3.28 ng/ml; P = 0.028). The mean PGE2-to-PGD2 ratio correlated strongly with VAS scoring (P = 0.008). In DE mice, COX-2 mRNA was significantly higher in ocular surface tissue and lacrimal glands. Furthermore, PGES mRNA was significantly higher in ocular surface tissue, whereas PGDS mRNA was decreased. Immunohistochemistry staining showed elevated COX-2 expression in the lacrimal glands, meibomian glands, corneas, and conjunctivas. Furthermore, PGES expression was found in periductal infiltrated cells of the lacrimal glands and conjunctival epithelium. Also, PGDS expression was decreased in meibomian glands and increased focally in the conjunctival epithelium.. A reciprocal change in PGE2 and PGD2 levels was found in the tears of DE patients, which correlated with patients' symptom scores. These clinical results were supported by increased COX-2 and PGES expression levels found in tear-producing tissues of DE mice.

Topics: Adult; Aged; Aged, 80 and over; Animals; Case-Control Studies; Chromatography, High Pressure Liquid; Cornea; Cross-Sectional Studies; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Disease Models, Animal; Dry Eye Syndromes; Epoprostenol; Female; Humans; Immunoenzyme Techniques; Intramolecular Oxidoreductases; Lacrimal Apparatus; Lipocalins; Male; Meibomian Glands; Mice; Mice, Inbred C57BL; Middle Aged; Prostaglandin D2; Prostaglandin-E Synthases; Real-Time Polymerase Chain Reaction; RNA, Messenger; Severity of Illness Index; Tandem Mass Spectrometry; Tears

Urinary excretion of lipocalin-type PGD(2) synthase (L-PGDS), which converts PG H(2) to PGD(2), increases in early diabetic nephropathy. In addition, L-PGDS expression in the tubular epithelium increases in adriamycin-induced nephropathy, suggesting that locally produced L-PGDS may promote the development of CKD. In this study, we found that L-PGDS-derived PGD(2) contributes to the progression of renal fibrosis via CRTH2-mediated activation of Th2 lymphocytes. In a mouse model, the tubular epithelium synthesized L-PGDS de novo after unilateral ureteral obstruction (UUO). L-PGDS-knockout mice and CRTH2-knockout mice both exhibited less renal fibrosis, reduced infiltration of Th2 lymphocytes into the cortex, and decreased production of the Th2 cytokines IL-4 and IL-13. Furthermore, oral administration of a CRTH2 antagonist, beginning 3 days after UUO, suppressed the progression of renal fibrosis. Ablation of IL-4 and IL-13 also ameliorated renal fibrosis in the UUO kidney. Taken together, these data suggest that blocking the activation of CRTH2 by PGD(2) might be a strategy to slow the progression of renal fibrosis in CKD.

Topics: Animals; Carbazoles; Disease Models, Animal; Fibrosis; Humans; Interleukin-13; Interleukin-4; Intramolecular Oxidoreductases; Kidney Diseases; Lipocalins; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; RNA, Messenger; Signal Transduction; Sulfonamides; Th2 Cells; Ureteral Obstruction

Rebound is known to occur most typically when topical glucocorticoids are abruptly discontinued; however, its frequency and severity are poorly characterized. We previously created a novel murine model of topical glucocorticoid-induced pruritus; however, the mechanism underlying pruritus in this model has not been elucidated. Using this murine model, we aimed to determine the cause of augmentation of pruritus with a focus on the production of prostaglandin (PG) D(2). BALB/c mice with chronic allergic contact dermatitis induced by 5 weeks of repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB) were treated topically with dexamethasone for 5 weeks immediately after the elicitation of dermatitis and after ear-swelling and scratching behavior were measured. RBL-2H3 mast cells were used to investigate the effect of dexamethasone on degranulation or PGD(2) production in IgE/antigen-stimulated mast cells. The scratching behavior induced by TNCB was augmented by topical application of dexamethasone, but dexamethasone did not have any effect on scratching bouts in mice that had not been treated with TNCB. Topical dexamethasone reduced the PGD(2) level, which increase in TNCB-treated mice, to the baseline level. Moreover, dexamethasone significantly decreased the PGD(2) production in IgE/antigen-stimulated RBL-2H3 mast cells; however, the same concentration of dexamethasone did not have any effect on the degranulation of stimulated mast cells. Topical glucocorticoids may exacerbate pruritus in a mouse model of allergic contact dermatitis via inhibition of PGD(2) production in antigen-mediated activated mast cells in the skin.

Topics: Administration, Topical; Animals; Dermatitis, Allergic Contact; Dexamethasone; Disease Models, Animal; Disease Progression; Female; Glucocorticoids; Mast Cells; Mice; Mice, Inbred BALB C; Picryl Chloride; Prostaglandin D2; Pruritus

Cyclopentenone prostaglandins (CyPGs), such as 15-deoxy-Δ(12,14) -prostaglandin J(2) (15d-PGJ(2)), are active prostaglandin metabolites exerting a variety of biological effects that may be important in the pathogenesis of neurological diseases. Ubiquitin-C-terminal hydrolase L1 (UCH-L1) is a brain specific deubiquitinating enzyme whose aberrant function has been linked to neurodegenerative disorders. We report that [15d-PGJ(2)] detected by quadrapole mass spectrometry (MS) increases in rat brain after temporary focal ischemia, and that treatment with 15d-PGJ(2) induces accumulation of ubiquitinated proteins and exacerbates cell death in normoxic and hypoxic primary neurons. 15d-PGJ(2) covalently modifies UCH-L1 and inhibits its hydrolase activity. Pharmacologic inhibition of UCH-L1 exacerbates hypoxic neuronal death while transduction with a TAT-UCH-L1 fusion protein protects neurons from hypoxia. These studies indicate that UCH-L1 function is important in hypoxic neuronal death and that excessive production of CyPGs after stroke may exacerbate ischemic injury by modification and inhibition of UCH-L1.

Topics: Animals; Cell Hypoxia; Cells, Cultured; Disease Models, Animal; Hypoxia-Ischemia, Brain; Nerve Degeneration; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Transduction, Genetic; Ubiquitin Thiolesterase

Otitis media is one of the most common and intractable ear diseases, and is the major cause of hearing loss, especially in children. Multiple factors affect the onset or development of otitis media. Prostaglandin D₂ is the major prostanoid involved in infection and allergy. However, the role of prostaglandin D₂ and prostaglandin D2 receptors on the pathogenesis of otitis media remains to be determined. Recent studies show that D prostanoid receptor (DP) and chemoattractant receptor-homologous molecule expressed on T helper type 2 (Th2) cells (CRTH2) are major prostaglandin D₂ receptors. In this study, homozygous DP single gene-deficient (DP⁻(/)⁻) mice, CRTH2 single gene-deficient (CRTH2⁻(/)⁻) mice and DP/CRTH2 double gene-deficient (DP⁻(/)⁻ CRTH2⁻(/)⁻) mice were used to investigate the role of prostaglandin D₂ and its receptors in otitis media. We demonstrate that prostaglandin D₂ is induced by lipopolysaccharide (LPS), a major component of Gram-negative bacteria, and that transtympanic injection of prostaglandin D₂ up-regulates macrophage inflammatory protein 2 (MIP-2), interleukin (IL)-1β and IL-6 in the middle ear. We also show that middle ear inflammatory reactions, including infiltration of inflammatory cells and expression of MIP-2, IL-1β and IL-6 induced by LPS, are reduced significantly in DP⁻(/)⁻ mice and DP⁻(/)⁻ CRTH2⁻(/)⁻ mice. CRTH2⁻(/)⁻ mice display inflammatory reactions similar to wild-type mice. These findings indicate that prostaglandin D₂ may play significant roles in LPS-induced experimental otitis media via DP.

Topics: Animals; Chemokine CXCL2; Cytokines; Disease Models, Animal; Female; Interleukin-1beta; Interleukin-6; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Otitis Media; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Th2 Cells

Fetal alcohol spectrum disorders (FASD) result from ethanol exposure to the developing fetus and are the most common cause of mental retardation in the United States. These disorders are characterized by a variety of neurodevelopmental and neurodegenerative anomalies which result in significant lifetime disabilities. Thus, novel therapies are required to limit the devastating consequences of FASD. Neuropathology associated with FASD can occur throughout the central nervous system (CNS), but is particularly well characterized in the developing cerebellum. Rodent models of FASD have previously demonstrated that both Purkinje cells and granule cells, which are the two major types of neurons in the cerebellum, are highly susceptible to the toxic effects of ethanol. The current studies demonstrate that ethanol decreases the viability of cultured cerebellar granule cells and microglial cells. Interestingly, microglia have dual functionality in the CNS. They provide trophic and protective support to neurons. However, they may also become pathologically activated and produce inflammatory molecules toxic to parenchymal cells including neurons. The findings in this study demonstrate that the peroxisome proliferator-activated receptor-γ agonists 15-deoxy-Δ12,15 prostaglandin J2 and pioglitazone protect cultured granule cells and microglia from the toxic effects of ethanol. Furthermore, investigations using a newly developed mouse model of FASD and stereological cell counting methods in the cerebellum elucidate that ethanol administration to neonates is toxic to both Purkinje cell neurons as well as microglia, and that in vivo administration of PPAR-γ agonists protects these cells. In composite, these studies suggest that PPAR-γ agonists may be effective in limiting ethanol-induced toxicity to the developing CNS.

Topics: Analysis of Variance; Animals; Brain; Cell Count; Cell Survival; Cells, Cultured; Disease Models, Animal; Ethanol; Female; Fetal Alcohol Spectrum Disorders; Mice; Mice, Inbred C57BL; Microglia; Neurons; Pioglitazone; PPAR gamma; Pregnancy; Prostaglandin D2; Thiazolidinediones

Retinopathy of prematurity (ROP) is a major cause of visual handicap in the pediatric population. To date, this disorder is thought to stem from deficient retinal vascularization. Intriguingly, functional electrophysiological studies in patients with mild or moderate ROP and in the oxygen-induced retinopathy (OIR) model in rats reveal central photoreceptor disruption that overlies modest retinal vessel loss; a paucity of retinal vasculature occurs predominantly at the periphery. Given that choroidal circulation is the major source of oxygen and nutrients to the photoreceptors, the authors set out to investigate whether the choroidal vasculature system may be affected in OIR.. Rat models of OIR treating newborn animals with 80% or 50/10% alternated oxygen level for the first two postnatal weeks were used to mimic ROP in humans. Immunohistology staining and vascular corrosion casts were used to investigate the vessel layout of the eye. To investigate the effect of 15-deoxy-Δ12,14-PGJ(2) (15d-PGJ(2); a nonenzymatic product of prostaglandin D(2)) on endothelial cells, in vitro cell culture and ex vivo choroid explants were employed and intravitreal injections were performed in animals.. The authors herein demonstrate that deficient vascularity occurs not only in the retinal plexus but also in the choroid. This sustained, marked choroidal degeneration is specifically confined to central regions of the retina that present persistent photoreceptor loss and corresponding functional deficits. Moreover, the authors show that 15d-PGJ(2) is a prominent contributor to this choroidal decay.. The authors demonstrate for the first time pronounced, sustained choroidal vascular involution during the development of ROP. Findings also suggest that effective therapeutic strategies to counter ROP should consider choroidal preservation.

Topics: Animals; Animals, Newborn; Blotting, Western; Choroid; Choroid Diseases; Corrosion Casting; Disease Models, Animal; Electroretinography; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Infant, Newborn; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Night Vision; Oxygen; Photoreceptor Cells, Vertebrate; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Retinopathy of Prematurity

We investigated the role of hematopoietic prostaglandin D synthase (H-PGDS) in biphasic nasal obstruction in allergic rhinitis using a new specific inhibitor, (N-methoxy-N-methyl)-4-(5-benzoylbenzimidazole-2-yl)-3,5-dimethylpyrrole-2-carboxamide hydrochloride (TAS-204). First, we developed a novel guinea pig model of allergic rhinitis. Guinea pigs sensitized to ovalbumin without adjuvant were challenged with intranasal exposure to ovalbumin once a week. After the 3rd antigen challenge, they exhibited biphasic nasal obstruction. Additionally, analysis of nasal lavage fluid revealed an increase in the level of prostaglandin D(2) in both early and late phases. Treatment with oral TAS-204 for 15 days during the period of antigen challenges suppressed increases in nasal airway resistance in both phases. It is noteworthy that the late phase nasal obstruction was almost completely abrogated by inhibiting H-PGDS alone. Eosinophil infiltration in nasal lavage fluid and nasal hyperresponsiveness to histamine was also reduced by TAS-204 administration. These findings suggest that H-PGDS plays a critical role in the development of allergic rhinitis, especially in the induction of late phase nasal obstruction.

Topics: Animals; Benzimidazoles; Dinoprostone; Disease Models, Animal; Eosinophils; Guinea Pigs; Histamine; Humans; Intramolecular Oxidoreductases; Leukotrienes; Lipocalins; Male; Nasal Lavage Fluid; Nasal Mucosa; Nasal Obstruction; Ovalbumin; Prostaglandin D2; Pyrroles; Rhinitis; Time Factors

Systemic administration of thiazolidinediones reduces peripheral inflammation in vivo, presumably by acting at peroxisome proliferator-activated receptor gamma (PPARgamma) in peripheral tissues. Based on a rapidly growing body of literature indicating the CNS as a functional target of PPARgamma actions, we postulated that brain PPARgamma modulates peripheral edema and the processing of inflammatory pain signals in the dorsal horn of the spinal cord. To test this in the plantar carrageenan model of inflammatory pain, we measured paw edema, heat hyperalgesia, and dorsal horn expression of the immediate-early gene c-fos after intracerebroventricular (ICV) administration of PPARgamma ligands or vehicle. We found that ICV rosiglitazone (0.5-50 microg) or 15d-PGJ(2) (50-200 microg), but not vehicle, dose-dependently reduced paw thickness, paw volume and behavioral withdrawal responses to noxious heat. These anti-inflammatory and anti-hyperalgesia effects result from direct actions in the brain and not diffusion to other sites, because intraperitoneal and intrathecal administration of rosiglitazone (50 microg) and 15d-PGJ(2) (200 microg) had no effect. PPARgamma agonists changed neither overt behavior nor motor coordination, indicating that non-specific behavioral effects do not contribute to PPAR ligand-induced anti-hyperalgesia. ICV administration of structurally dissimilar PPARgamma antagonists (either GW9662 or BADGE) reversed the anti-inflammatory and anti-hyperalgesic actions of both rosiglitazone and 15d-PGJ(2). To evaluate the effects of PPARgamma agonists on a classic marker of noxious stimulus-evoked gene expression, we quantified Fos protein expression in the dorsal horn. The number of carrageenan-induced Fos-like immunoreactive profiles was less in rosiglitazone-treated rats as compared to vehicle controls. We conclude that pharmacological activation of PPARgamma in the brain rapidly inhibits local edema and the spinal transmission of noxious inflammatory signals.

Topics: Anilides; Animals; Benzhydryl Compounds; Brain; Central Nervous System Agents; Disease Models, Animal; Edema; Epoxy Compounds; Gene Expression; Inflammation; Male; Pain; PPAR gamma; Prostaglandin D2; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Rosiglitazone; Spinal Cord; Thiazolidinediones

Background and Purpose- Hyperlipidemia is associated with platelet hyperreactivity. We hypothesized that L-4F, an apolipoprotein A-I mimetic peptide, would inhibit platelet aggregation in hyperlipidemic mice.. Injecting L-4F into apolipoprotein E (apoE)-null and low-density lipoprotein receptor-null mice resulted in a significant reduction in platelet aggregation in response to agonists; however, there was no reduction in platelet aggregation after injection of L-4F into wild-type (WT) mice. Consistent with these results, injection of L-4F into apoE-null mice prolonged bleeding time; the same result was not found in WT mice. Incubating L-4F in vitro with apoE-null platelet-rich plasma also resulted in decreased platelet aggregation. However, incubating washed platelets from either apoE-null or WT mice with L-4F did not alter aggregation. Compared with WT mice, unstimulated platelets from apoE-null mice contained significantly more 12-hydroxy 5,8,10,14-eicosatetraenoic acid, thromboxane A(2), and prostaglandins D(2) and E(2). In response to agonists, platelets from L-4F-treated apoE-null mice formed significantly less thromboxane A(2), prostaglandins D(2) and E(2), and 12-hydroxy 5,8,10,14-eicosatetraenoic acid.. By binding plasma-oxidized lipids that cause platelet hyperreactivity in hyperlipidemic mice, L-4F decreases platelet aggregation.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adenosine Diphosphate; Animals; Apolipoprotein A-I; Apolipoproteins E; Arachidonic Acid; Blood Coagulation; Collagen; Dinoprostone; Disease Models, Animal; Hyperlipidemias; Injections, Subcutaneous; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Mimicry; Peptides; Platelet Aggregation; Platelet Aggregation Inhibitors; Platelet Function Tests; Prostaglandin D2; Receptors, LDL; Thromboxane A2

Acute obstructive cholangitis is a common disease with a high mortality rate. Ligands for peroxisome proliferator-activated receptor-gamma (PPARgamma), such as 15-deoxy-Delta(12,14)-prostaglandin J(2) (15D-PGJ(2)), have been proposed as a new class of anti-inflammatory compounds. This study investigated the effect of 15D-PGJ(2) treatment on lipopolysaccharide (LPS)-induced acute obstructive cholangitis. The rats were randomly assigned to five groups: sham operation (Sham; simple laparotomy), sham operation with intraperitoneal saline infusion (Sham+Saline), sham operation with intraperitoneal LPS infusion (Sham+LPS), bile duct ligation (BDL) with saline infusion into the bile duct (BDL+Saline), and BDL with LPS infusion into the bile duct (BDL+LPS). Biochemical assays of blood samples, histology of the liver, portal venous pressure, hyaluronic acid clearance, and expression of inflammation-associated genes in the liver were evaluated. Furthermore, the Sham+LPS and the BDL+LPS group were divided into two groups (with and without 15D-PGJ(2) treatment), and their survival rates were compared. Biochemical assays of blood samples, portal venous pressure, hyaluronic acid clearance, and expression of inflammation-associated genes in the liver were all significantly higher in the BDL+LPS group compared with those in the BDL+Saline group, indicating the presence of increased liver damage in the first group. However, preoperative administration of 15D-PGJ(2) significantly improved these outcomes. Furthermore, the survival rate after establishment of cholangitis was significantly improved by the administration of 15D-PGJ(2) in the BDL+LPS group. These results clearly demonstrate that 15D-PGJ(2) inhibits the inflammatory response and endothelial cell damage seen in acute obstructive cholangitis and could contribute to improve the outcome of this pathology.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Bile Ducts; Bilirubin; Cholangitis; Cholestasis, Extrahepatic; Disease Models, Animal; Endothelium, Vascular; Gene Expression; Hyaluronic Acid; Interleukin-6; Ligation; Lipopolysaccharides; Liver; Liver Circulation; Liver Failure, Acute; Male; NF-kappa B; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; PPAR gamma; Prostaglandin D2; Rats; Rats, Wistar; Survival Analysis; Tumor Necrosis Factor-alpha

We report here that 4-dibenzo[a,d]cyclohepten-5-ylidene-1-[4-(2H-tetrazol-5-yl)-butyl]-piperidine (AT-56) is an orally active and selective inhibitor of lipocalin-type prostaglandin (PG) D synthase (L-PGDS). AT-56 inhibited human and mouse L-PGDSs in a concentration (3-250 microm)-dependent manner but did not affect the activities of hematopoietic PGD synthase (H-PGDS), cyclooxygenase-1 and -2, and microsomal PGE synthase-1. AT-56 inhibited the L-PGDS activity in a competitive manner against the substrate PGH(2) (K(m) = 14 microm) with a K(i) value of 75 microm but did not inhibit the binding of 13-cis-retinoic acid, a nonsubstrate lipophilic ligand, to L-PGDS. NMR titration analysis revealed that AT-56 occupied the catalytic pocket, but not the retinoid-binding pocket, of L-PGDS. AT-56 inhibited the production of PGD(2) by L-PGDS-expressing human TE-671 cells after stimulation with Ca(2+) ionophore (5 microm A23187) with an IC(50) value of about 3 microm without affecting their production of PGE(2) and PGF(2alpha) but had no effect on the PGD(2) production by H-PGDS-expressing human megakaryocytes. Orally administered AT-56 (<30 mg/kg body weight) decreased the PGD(2) production to 40% in the brain of H-PGDS-deficient mice after a stab wound injury in a dose-dependent manner without affecting the production of PGE(2) and PGF(2alpha) and also suppressed the accumulation of eosinophils and monocytes in the bronco-alveolar lavage fluid from the antigen-induced lung inflammation model of human L-PGDS-transgenic mice.

Topics: Administration, Oral; Animals; Calcimycin; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprost; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Enzyme Inhibitors; Eosinophils; Humans; Intramolecular Oxidoreductases; Ionophores; Lipocalins; Male; Megakaryocytes; Membrane Proteins; Mice; Mice, Knockout; Monocytes; Pneumonia; Prostaglandin D2; Wound Healing; Wounds, Stab

Duchenne muscular dystrophy is a fatal muscle wasting disease that is characterized by a deficiency in the protein dystrophin. Previously, we reported that the expression of hematopoietic prostaglandin D synthase (HPGDS) appeared in necrotic muscle fibers from patients with either Duchenne muscular dystrophy or polymyositis. HPGDS is responsible for the production of the inflammatory mediator, prostaglandin D(2). In this paper, we validated the hypothesis that HPGDS has a role in the etiology of muscular necrosis. We investigated the expression of HPGDS/ prostaglandin D(2) signaling using two different mouse models of muscle necrosis, that is, bupivacaine-induced muscle necrosis and the mdx mouse, which has a genetic muscular dystrophy. We treated each mouse model with the HPGDS-specific inhibitor, HQL-79, and measured both necrotic muscle volume and selected cytokine mRNA levels. We confirmed that HPGDS expression was induced in necrotic muscle fibers in both bupivacaine-injected muscle and mdx mice. After administration of HQL-79, necrotic muscle volume was significantly decreased in both mouse models. Additionally, mRNA levels of both CD11b and transforming growth factor beta1 were significantly lower in HQL-79-treated mdx mice than in vehicle-treated animals. We also demonstrated that HQL-79 suppressed prostaglandin D(2) production and improved muscle strength in the mdx mouse. Our results show that HPGDS augments inflammation, which is followed by muscle injury. Furthermore, the inhibition of HPGDS ameliorates muscle necrosis even in cases of genetic muscular dystrophy.

Topics: Anesthetics, Local; Animals; Blotting, Western; Bupivacaine; Cytokines; Disease Models, Animal; Humans; Intramolecular Oxidoreductases; Lipocalins; Male; Mice; Mice, Inbred C57BL; Mice, Inbred mdx; Mice, Knockout; Mice, Transgenic; Muscle, Skeletal; Muscular Dystrophy, Animal; Necrosis; Piperidines; Prostaglandin D2; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Growth hormone-releasing peptides (GHRPs) as CD36 selective ligands feature potent anti-atherosclerotic activity that is associated with an upregulation of the peroxisome proliferator-activated receptor gamma (PPARgamma)-liver X receptor alpha (LXRalpha)-ATP-binding cassette (ABC) transporter pathway. However, the mechanism involved in PPARgamma activation in response to CD36 signalling has yet to be determined. Therefore, the present study aims to elucidate the upstream molecular mechanisms through which EP 80317, a selective CD36 ligand, promotes lipid efflux from macrophages through PPARgamma activation.. [3H]-Cholesterol- and [3H]-methylcholine chloride-labelled murine macrophages treated with EP 80317 showed a significant increase in cholesterol and phospholipid efflux to both apolipoprotein A-I and high-density lipoprotein in a CD36-dependent manner. Lipid efflux was associated with enhanced activation of PPARgamma. The signalling pathway by which this CD36 ligand promoted lipid efflux involved an increase in intracellular 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2) levels induced by extracellular signal-regulated kinase 1/2 (ERK1/2)-dependent cyclooxygenase-2 (COX-2) expression, leading to PPARgamma activation. In agreement, EP 80317-mediated cholesterol efflux was abrogated by inhibitors of PPARgamma, ERK1/2, and COX-2 as well as ABC transporter inhibitors, whereas a p38 mitogen-activated protein kinase inhibitor had no effect.. These findings suggest a central role for the prostanoid 15d-PGJ2 in PPARgamma activation and the upregulation of the ABC transporter pathway in response to CD36 activation by synthetic GHRPs analogues. The resulting enhanced cholesterol efflux might explain, at least in part, the atheroprotective effect of selective CD36 ligands.

Topics: Animals; Apolipoprotein A-I; Apolipoproteins E; Atherosclerosis; ATP Binding Cassette Transporter 1; ATP Binding Cassette Transporter, Subfamily G, Member 1; ATP-Binding Cassette Transporters; Biological Transport; Cardiovascular Agents; CD36 Antigens; Cell Line; Cholesterol; Cyclooxygenase 2; Disease Models, Animal; Lipoproteins; Lipoproteins, HDL; Macrophages, Peritoneal; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Oligopeptides; Phospholipids; PPAR gamma; Prostaglandin D2; Signal Transduction; Time Factors

Prostaglandin (PG) D(2) is the major cylooxygenase metabolite released by mast cells upon allergen stimulation, and elicits responses through either the prostanoid DP1 receptor and/or the chemoattractant receptor homologous molecule expressed on T-helper type 2 (Th2) cells (CRTH2/DP2). Experimental evidence suggests that stimulation of one or both these receptors contributes to asthma pathophysiology.. The aim of this study was to test the hypothesis that the prostanoid DP1 receptor contributes to asthma pathophysiology by determining the efficacy of an orally active antagonist for this receptor, S-5751, on allergen-induced bronchoconstriction, airway hyperresponsiveness (AHR) and cellular inflammation in the sheep model of asthma.. PGD(2)-induced cyclic adenosine monophosphate (cAMP) production in platelet-rich plasma was used to establish the in vitro efficacy of S-5751. In vivo, sheep naturally allergic to Ascaris suum were challenged with an aerosolized antigen with and without S-5751 treatment (given 4 days before and for 6 days after the challenge).. S-5751 inhibited PGD(2)-induced cAMP production in platelet-rich plasma with an IC(50) value of 0.12 microm. S-5751 at 30 mg/kg, but not at 3 mg/kg, reduced the early bronchoconstriction and inhibited the late bronchoconstriction. AHR and inflammatory cell infiltration in bronchoalveolar lavage fluid at days 1 and 7 were also inhibited with the 30 mg/kg dose. The responses observed with S-5751 at 30 mg/kg were comparable with those with montelukast treatment (0.15 mg/kg, twice a day, intravenous); however, S-5751 did not block inhaled leukotrieneD(4)-induced broncoconstriction.. Prostanoid DP1 receptor inhibition may represent an alternative target for asthma therapy.

Topics: Acetates; Allergens; Animals; Anti-Asthmatic Agents; Asthma; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Cyclic AMP; Cyclopropanes; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Humans; Prostaglandin D2; Quinolines; Receptors, Immunologic; Receptors, Prostaglandin; Sulfides; Thiophenes; Time Factors

The neuroprotective effects and mechanism of action of GIF-0173, a Delta12-prostaglandin J analogue, were investigated in the early phase of cerebral ischemia. GIF-0173 was administered intravenously immediately following middle cerebral artery occlusion (MCAO) in photochemically induced thrombosis model of rat. Neurological scores and infarct sizes were examined at 24 h after MCAO. Cerebral blood flow (CBF) was monitored by laser-Doppler flowmetry for 1 h after MCAO. In cultured cortical neurons obtained from 1-day-old rats, the effects of GIF-0173 on the excitotoxicity induced by glutamate were examined. Morphological changes, neuronal death, and changes in intracellular calcium concentration ([Ca(2+)](i)) were also examined. GIF-0173 improved neurological scores and reduced the infarct size in a dose-dependent manner following MCAO. But GIF-0173 did not improve CBF after MCAO. GIF-0173 also prevented glutamate-induced neuronal death and acute cellular swelling in primary cultures in a dose-dependent manner, indicating that it inhibited neuronal necrosis. GIF-0173 dose-dependently suppressed the glutamate-induced increase in [Ca(2+)](i), but could not inhibit NMDA-induced calcium influx. The effects of GIF-0173 against glutamate-induced [Ca(2+)](i) increase were reversed by addition of non-specific prostaglandin D (PGD(2)) receptor antagonist and were comparable to the effects of PGD(2) DP1 receptor agonist, which prevented [Ca(2+)](i) increase and neuronal death. We conclude that GIF-0173 reduces cerebral infarction and protects cultured neurons against glutamate-induced excitotoxicity by inhibiting [Ca(2+)](i) increase through DP1 receptor activation.

Topics: Animals; Brain Infarction; Calcium; Cell Death; Cells, Cultured; Cerebral Cortex; Cerebrovascular Circulation; Dantrolene; Disease Models, Animal; Dose-Response Relationship, Drug; Glutamic Acid; Hydantoins; Infarction, Middle Cerebral Artery; Intracellular Fluid; Lactones; Laser-Doppler Flowmetry; Male; N-Methylaspartate; Neurons; Neuroprotective Agents; Platelet Aggregation Inhibitors; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, Immunologic; Receptors, Prostaglandin; Sesquiterpenes; Severity of Illness Index; Tetrazolium Salts

Chronic neuroinflammation is implicated in Parkinson's disease (PD). Inflammation involves the activation of microglia and astrocytes that release high levels of prostaglandins. There is a profound gap in our understanding of how cyclooxygenases and their prostaglandin products redirect cellular events to promote PD neurodegeneration. The major prostaglandin in the mammalian brain is prostaglandin D2, which readily undergoes spontaneous dehydration to generate the bioactive cyclopentenone prostaglandins of the J2 series. These J2 prostaglandins are highly reactive and neurotoxic products of inflammation shown in cellular models to impair the ubiquitin/proteasome pathway and cause the accumulation of ubiquitinated proteins. PD is a disorder that exhibits accumulation of ubiquitinated proteins in neuronal inclusions (Lewy bodies). The role of J2 prostaglandins in promoting PD neurodegeneration has not been investigated under in vivo conditions.. We addressed the neurodegenerative and behavioral effects of the administration of prostaglandin J2 (PGJ2) simultaneously into the substantia nigra/striatum of adult male FVB mice by subchronic microinjections. One group received unilateral injections of DMSO (vehicle, n = 6) and three groups received PGJ2 [3.4 microg or 6.7 microg (n = 6 per group) or 16.7 microg (n = 5)] per injection. Immunohistochemical and behavioral analyses were applied to assess the effects of the subchronic PGJ2 microinfusions.. Immunohistochemical analysis demonstrated a PGJ2 dose-dependent significant and selective loss of dopaminergic neurons in the substantia nigra while the GABAergic neurons were spared. PGJ2 also triggered formation of aggregates immunoreactive for ubiquitin and alpha-synuclein in the spared dopaminergic neurons. Moreover, PGJ2 infusion caused a massive microglia and astrocyte activation that could initiate a deleterious cascade leading to self-sustained progressive neurodegeneration. The PGJ2-treated mice also exhibited locomotor and posture impairment.. Our studies establish the first model of inflammation in which administration of an endogenous highly reactive product of inflammation, PGJ2, recapitulates key aspects of PD. Our novel PGJ2-induced PD model strongly supports the view that localized and chronic production of highly reactive and neurotoxic prostaglandins, such as PGJ2, in the CNS could be an integral component of inflammation triggered by insults evoked by physical, chemical or microbial stimuli and thus establishes a link between neuroinflammation and PD neurodegeneration.

Topics: alpha-Synuclein; Animals; Cell Death; Disease Models, Animal; Dopamine; Dose-Response Relationship, Drug; Drug Administration Schedule; Encephalitis; Gliosis; Immunohistochemistry; Inclusion Bodies; Inflammation Mediators; Male; Mice; Microinjections; Movement Disorders; Nerve Degeneration; Neurons; Parkinsonian Disorders; Prostaglandin D2; Substantia Nigra

Maternal diabetes is associated with morphological placental abnormalities and foeto-placental impairments. These alterations are linked with a dysregulation of the activity of matrix metalloproteinases (MMPs). We investigated the action of 15deoxyDelta(12,14) prostaglandin J(2) (15dPGJ(2)), a natural ligand of the peroxisome proliferator activated receptor (PPAR) gamma, on MMP-2 and MMP-9 activities and tissue inhibitors of matrix metalloproteinases (TIMP) levels in foetuses and placentas from diabetic rats.. Diabetes was induced in rat neonates by a single streptozotocin administration (90 mg kg(-1) s.c.). At 13.5 days of gestation, foetal and placental homogenates were prepared for the determination of PPARgamma levels (western blot) and 15dPGJ(2) concentration (enzyme-immunoassay), whereas the in vitro effect of 15dPGJ(2) (2 microM) was evaluated on placental and foetal MMPs and TIMP activities (zymography and reverse zymography), nitrate/nitrite concentrations (Griess method) and thiobarbituric acid reactive substances (TBARS).. PPARgamma was increased while 15dPGJ(2) was decreased in placentas and foetuses from diabetic rats. 15dPGJ(2) additions were able to reduce the high activities of MMP-2 and MMP-9 present in diabetic placental tissues. 15dPGJ(2) additions reduced MMP-2 activity in control and diabetic foetuses. TIMP-3 levels were decreased in diabetic placentas and 15dPGJ(2) was able to enhance them to control values. Nitrates/nitrites and TBARS, metabolites of MMPs activators, were increased in the diabetic placenta and reduced by 15dPGJ(2).. This study demonstrates that 15dPGJ(2) is a potent modulator of the balance between MMP activities and TIMP levels, which is needed in the correct formation and function of the placenta and foetal organs.

Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Female; Fetus; Gelatinases; Matrix Metalloproteinases; Nitric Oxide; Placenta; PPAR gamma; Pregnancy; Prostaglandin D2; Rats; Rats, Wistar; Tissue Inhibitor of Metalloproteinases

Neutrophils (polymorphonuclear leukocytes [PMNs]) are critical to the immune response, including clearance of infectious pathogens. Sepsis is associated with impaired PMN function, including chemotaxis. PMNs express peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a ligand-activated nuclear transcription factor involved in immune and inflammatory regulation. The role of PPAR-gamma in PMN responses, however, is not well characterized. We report that freshly isolated human PMNs constitutively express PPAR-gamma, which is up-regulated by the sepsis-induced cytokines TNF-alpha and IL-4. PMN chemotactic responses to formylmethionyl-leucyl-phenylalanine (fMLP) and IL-8 were dose-dependently inhibited by treatment with the PPAR-gamma ligands troglitazone and 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) and by transfection of PMN-like HL-60 cells with a constitutively active PPAR-gamma construct. Inhibition of chemotaxis by PPAR-gamma ligands correlated with decreases in extracellular signal-regulated kinase-1 and -2 activation, actin polymerization, and adherence to a fibrinogen substrate. Furthermore, PMN expression of PPAR-gamma was increased in sepsis patients and mice with either of 2 models of sepsis. Finally, treatment with the PPAR-gamma antagonist GW9662 significantly reversed the inhibition of PMN chemotaxis and increased peritoneal PMN recruitment in murine sepsis. This study indicates that PPAR-gamma activation is involved in PMN chemotactic responses in vitro and may play a role in the migration of these cells in vivo.

Topics: Actins; Anilides; Animals; Antineoplastic Agents; Cell Adhesion; Chemotaxis; Chromans; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Fibrinogen; HL-60 Cells; Humans; Inflammation; Interleukin-4; Interleukin-8; Male; Mice; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; N-Formylmethionine Leucyl-Phenylalanine; PPAR gamma; Prostaglandin D2; Sepsis; Thiazolidinediones; Troglitazone; Tumor Necrosis Factor-alpha; Up-Regulation

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-dependent nuclear receptor that plays an important role in placental development and function metabolism in diabetic and control rats after midpregnancy, as well as the concentrations of the PPARgamma endogenous agonist 15deoxyDelta(12,14)Prostaglandin J(2) (15dPGJ(2)). In vitro experiments showed that 15dPGJ(2) did not regulate placental concentrations of triglycerides, cholesteryl esters, phospholipids and free fatty acids, but decreased the de novo synthesis of these lipid species. PPAR agonists were administered in vivo through dietary supplementation with either 6% olive oil or 6% safflower oil. These treatments led to increases in placental lipid mass in control tissues and more markedly in diabetic tissues. In addition, they led to reductions in the de novo lipid synthesis both in control and in diabetic placental tissues. In the placenta from diabetic rats fed with the standard diet, 15dPGJ(2) concentrations were greatly reduced. Both dietary supplementations increased the concentrations of 15dPGJ(2) in placentas from control and diabetic rats. These data indicate that, in the placenta, PPARgamma natural ligands regulate the concentration of their own endogenous ligands. In addition, they increase the placental capacity to accumulate maternal-derived lipids, and reduce the de novo lipid synthesis, thus regulating metabolic pathways that are altered in the placenta from diabetic rats and involved in the lipid transfer to the developing fetus.

Topics: Animals; Diabetes Mellitus, Experimental; Dietary Fats; Disease Models, Animal; Female; Fetal Weight; Immunoenzyme Techniques; Lipid Metabolism; Male; Placenta; PPAR gamma; Pregnancy; Prostaglandin D2; Random Allocation; Rats; Rats, Wistar

Peroxisome proliferator-activated receptor (PPAR) gamma is a member of the nuclear-receptor superfamily that binds to DNA with retinoid X receptors as PPAR-retinoid X receptor heterodimers. Recent evidence also suggests that the cyclopentenone prostaglandin 15-deoxy-DeltaPGJ2 (15d-PGJ2), which is a metabolite of the prostaglandin D2, functions as an endogenous ligand for PPAR-gamma We postulated that 15d-PGJ2 would attenuate inflammation, investigating the effects on the degree of experimental spinal cord trauma induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration, production of a range of inflammatory mediators, tissue damage, and apoptosis. Furthermore, 15d-PGJ2 reduced (1) spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (myeloperoxidase activity), (3) nuclear factor-kappaB activation, (4) expression of iNOS, nitrotyrosine and TNF-alpha, and (5) apoptosis (terminal deoxynucleotidyltransferase-mediated uridine triphosphate end labeling staining, Bax, Bcl-2, and FAS-L expression). In a separate set of experiments, 15d-PGJ2 significantly ameliorated the recovery of limb function (evaluated by motor recovery score). To elucidate whether the protective effects of 15d-PGJ2 are related to activation of the PPAR-gamma receptor, we also investigated the effect of a PPAR-gamma antagonist, GW 9662, on the protective effects of 15d-PGJ2. GW9662 (1 mg/kg administered i.p. 30 min before treatment with 15d-PGJ2) significantly antagonized the effect of the PPAR-gamma agonist and, thus, abolished the protective effect. Taken together, our results clearly demonstrate that treatment with 15d-PGJ2 reduces the development of inflammation and tissue injury associated with spinal cord trauma.

Topics: Animals; Cyclization; Cyclopentanes; Disease Models, Animal; Inflammation Mediators; Ligands; Male; Mice; Mice, Inbred Strains; Neutrophil Infiltration; Peroxisome Proliferator-Activated Receptors; PPAR gamma; Prostaglandin D2; Random Allocation; Recovery of Function; Severity of Illness Index; Spinal Cord Injuries

Prostaglandin D2(PGD2) is the most produced prostanoid in the CNS of mammals, and in behavioral experiments it has been implicated in the modulation of spinal nociception. In the present study we addressed the effects of spinal PGD2 on the discharge properties of nociceptive spinal cord neurons with input from the knee joint using extracellular recordings in vivo, both in normal rats and in rats with acute inflammation in the knee joint. Topical application of PGD2 to the spinal cord of normal rats did not influence responses to mechanical stimulation of the knee and ankle joint except at a high dose. Specific agonists at either the prostaglandin D2 receptor 1 (DP1) or the prostaglandin D2 receptor 2 (DP2) receptor had no effect on responses to mechanical stimulation of the normal knee. By contrast, in rats with inflamed knee joints either PGD2 or a DP1 receptor agonist decreased responses to mechanical stimulation of the inflamed knee and the non-inflamed ankle thus reducing established inflammation-evoked spinal hyperexcitability. Vice versa, spinal application of an antagonist at DP1 receptors increased responses to mechanical stimulation of the inflamed knee joint and the non-inflamed ankle joint suggesting that endogenous PGD2 attenuated central sensitization under inflammatory conditions, through activation of DP1 receptors. Spinal application of a DP2 receptor antagonist had no effect. The conclusion that spinal PGD2 attenuates spinal hyperexcitability under inflammatory conditions is further supported by the finding that spinal coapplication of PGD2 with prostaglandin E2 (PGE2) attenuated the PGE2-induced facilitation of responses to mechanical stimulation of the normal joint.

Topics: Action Potentials; Acute Disease; Afferent Pathways; Animals; Arthralgia; Arthritis; Dinoprostone; Disease Models, Animal; Dose-Response Relationship, Drug; Hindlimb; Nociceptors; Physical Stimulation; Posterior Horn Cells; Prostaglandin D2; Rats; Receptors, Immunologic; Receptors, Prostaglandin; Tarsus, Animal

We examined the role of prostanoid DP receptor in nasal blockage in an experimental allergic rhinitis model in guinea pigs. Local inhalation of prostaglandin D(2) (PGD(2)) to the nasal cavity resulted in an increase in intranasal pressure in guinea pigs actively sensitized by repeated antigen exposure but not in non-sensitized guinea pigs. Nasal hyperresponsiveness was observed when the guinea pigs were exposed to histamine and U-46619 (11alpha, 9alpha-epoxymethano-PGH(2); a thromboxane (TX) A(2) mimetic) after repeated antigen exposure. S-5751 ((Z)-7-[(1R,2R,3S,5S)-2-(5-hydroxybenzo[b]thiophen-3-ylcarbonylamino)-10-norpinan-3-yl]hept-5-enoic acid), a prostanoid DP receptor antagonist, inhibited not only PGD(2)-induced nasal blockage but also nasal hyperresponsiveness to histamine and U-46619 in sensitized guinea pigs. Combined exposure of the nasal cavity of guinea pigs to an aerosol of PGD(2) with histamine or U-46619 at sub-threshold concentrations synergistically caused a marked increase in intranasal pressure. These responses were significantly suppressed by S-5751. These results suggest that PGD(2) plays a critical role in the increase in intranasal pressure via prostanoid DP receptor, probably through synergistically enhancing the nasal response with other chemical mediators released from mast cells and other inflammatory cells activated by allergens.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Administration, Intranasal; Allergens; Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Guinea Pigs; Histamine; Male; Nasal Mucosa; Nasal Obstruction; Nose; Ovalbumin; Pressure; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Rhinitis, Allergic, Perennial; Thiophenes; Time Factors

PPAR-gamma has been known to induce suppression, differentiation and reversal of malignant changes in colon cancer in vitro. However, there are several reports that PPAR-gamma ligands enhance colon polyp development in APCmin mice in vivo. These contradictory results have not yet been thoroughly explained. To explain the contradictory results, we analyzed the effects of different concentrations of the PPAR-gamma agonist, 15-deoxy-D12, 14-prostaglandin (15-d Delta PGJ2) and pioglitazone, on APC gene-mutated colon cancer cell lines (HT-29). We measured cell growth and suppression by cell count and MTT assay and analyzed the expression of beta-catenin and c-Myc protein by Western blot. In addition, we inoculated HT-29 cells into APCmin mice to compare tumor size. High concentrations (10-100 microM/L 15-d Delta PGJ2 and pioglitazone) of PPAR-gamma ligand suppressed growth, while low concentrations (0.01-1 microM/L 15-d Delta PGJ2 and pioglitazone) of PPAR-gamma ligand promoted growth. In particular, the effects of 0.1 microM/L 15-d Delta PGJ2 and pioglitazone on cell growth were statistically significant (P = 0.003, P = 0.001, respectively). Tumor growth was associated with an increase in beta-catenin and c-Myc expression. The growth of xenograft tumors was greater in PPAR-gamma ligand-treated mice than in control mice (control vs day 14: P = 0.024, control vs day 28: P = 0.007). The expression of beta-catenin and c-Myc protein were also elevated in PPAR-gamma-treated mouse tissues. PPAR-gamma ligand can promote the growth of APC-mutated HT-29 colon cancer cells in vitro and in vivo. In addition, the tumor promoting effect seems to be associated with an increase in beta-catenin and c-Myc expression. We think that well-controlled clinical trials should be conducted to confirm our results and to verify clinical applications.

Topics: Animals; beta Catenin; Cell Proliferation; Colonic Neoplasms; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Genes, APC; HT29 Cells; Humans; Ligands; Mice; Mice, Nude; Mutation; Pioglitazone; PPAR gamma; Prostaglandin D2; Proto-Oncogene Proteins c-myc; Thiazolidinediones; Xenograft Model Antitumor Assays

Secondary tissue damage that occurs within days after spinal cord injury contributes significantly to permanent paralysis, sensory loss, and other functional disabilities. The acute inflammatory response is thought to contribute largely to this secondary damage. We show here that 15-deoxy-delta-12,14-prostaglandin J2 (15d-PGJ2), a metabolite of prostaglandin D2 (PGD2) that has anti-inflammatory actions, given daily for the first 2 weeks after spinal cord contusion injury in mice, results in significant improvement of sensory and locomotor function. 15d-PGJ2-treated mice also show diminished signs of microglia/macrophage activation, increased neuronal survival, greater serotonergic innervation, and reduced demyelination in the injured spinal cord. These changes are accompanied by a reduction in chemokine and pro-inflammatory cytokine expression. Our results also indicate that 15d-PGJ2 is likely to reduce inflammation in the injured spinal cord by attenuating multiple signaling pathways: reducing activation of NF-kappa B; enhancing expression of suppressor of cytokine signaling1 and reducing the activation of Janus activated Kinase 2.

Topics: Analysis of Variance; Animals; Behavior, Animal; Cell Survival; Demyelinating Diseases; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Activation; Female; Gene Expression Regulation; Immunologic Factors; Macrophages; Mice; Mice, Inbred BALB C; Microglia; Motor Activity; Nerve Tissue Proteins; Neurons; NF-kappa B; Prostaglandin D2; Spinal Cord Injuries; Suppressor of Cytokine Signaling 1 Protein; Suppressor of Cytokine Signaling Proteins; Time Factors

Sustained release niacin effectively lowers serum cholesterol, LDL and triglycerides, while raising HDL. However, 75% of patients experience cutaneous warmth and itching known as flush, leading to discontinuation. Acetylsalicylic acid (aspirin) reduces this flush only by about 30%, presumably through decreasing prostaglandin D2 (PGD2). We investigated whether niacin-induced flush in a rat model involves PGD2 and 5-HT, and the effect of certain flavonoids.. Three skin temperature measurements from each ear were recorded with an infrared pyrometer for each time point immediately before i.p. injection with either niacin or a flavonoid. The temperature was then measured every 10 min for 60 min.. Niacin (7.5 mg per rat, equivalent to a human dose of 1750 mg per 80 kg) maximally increased ear temperature to 1.9+/-0.2 degrees C at 45 min. Quercetin and luteolin (4.3 mg per rat; 1000 mg per human), administered i.p. 45 min prior to niacin, inhibited the niacin effect by 96 and 88%, respectively. Aspirin (1.22 mg per rat; 325 mg per human) inhibited the niacin effect by only 30%. Niacin almost doubled plasma PGD2 and 5-HT, but aspirin reduced only PGD2 by 86%. In contrast, luteolin inhibited both plasma PGD2 and 5-HT levels by 100 and 67%, respectively. CONCLUSIONS AND IMPLICATIONS. Niacin-induced skin temperature increase is associated with PGD2 and 5-HT elevations in rats; luteolin may be a better inhibitor of niacin-induced flush because it blocks the rise in both mediators.

Topics: Animals; Aspirin; Body Temperature; Disease Models, Animal; Flushing; Hypolipidemic Agents; Luteolin; Male; Niacin; Prostaglandin D2; Quercetin; Random Allocation; Rats; Rats, Sprague-Dawley; Serotonin; Skin

PGD(2) is the major prostanoid produced during the acute phase of allergic reactions. Two PGD(2) receptors have been isolated, DP and CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells), but whether they participate in the pathophysiology of allergic diseases remains unclear. We investigated the role of CRTH2 in the initiation of allergic rhinitis in mice. First, we developed a novel murine model of pollinosis, a type of seasonal allergic rhinitis. Additionally, pathophysiological differences in the pollinosis were compared between wild-type and CRTH2 gene-deficient mice. An effect of treatment with ramatroban, a CRTH2/T-prostanoid receptor dual antagonist, was also determined. Repeated intranasal sensitization with Cry j 1, the major allergen of Cryptomeria japonica pollen, in the absence of adjuvants significantly exacerbated nasal hyperresponsive symptoms, Cry j 1-specific IgE and IgG1 production, nasal eosinophilia, and Cry j 1-induced in vitro production of IL-4 and IL-5 by submandibular lymph node cells. Additionally, CRTH2 mRNA in nasal mucosa was significantly elevated in Cry j 1-sensitized mice. Following repeated intranasal sensitization with Cry j 1, CRTH2 gene-deficient mice had significantly weaker Cry j 1-specific IgE/IgG1 production, nasal eosinophilia, and IL-4 production by submandibular lymph node cells than did wild-type mice. Similar results were found in mice treated with ramatroban. These results suggest that the PGD(2)-CRTH2 interaction is elevated following sensitization and plays a proinflammatory role in the pathophysiology of allergic rhinitis, especially pollinosis in mice.

Topics: Allergens; Animals; Antigens, Plant; Carbazoles; Cryptomeria; Cytokines; Disease Models, Animal; Eosinophils; Immunoglobulins; Mice; Mice, Inbred BALB C; Mice, Mutant Strains; Nasal Mucosa; Nasal Septum; Plant Proteins; Pollen; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Rhinitis, Allergic, Seasonal; Sulfonamides; Th2 Cells

Experimental allergic encephalomyelitis (EAE) is a T cell-mediated autoimmune disease model for multiple sclerosis (MS). We have shown earlier that 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) and curcumin ameliorate EAE by modulating inflammatory signaling pathways in T lymphocytes. Toll-like receptors (TLRs), expressed primarily in innate immune cells, play critical roles in the pathogenesis of EAE. T lymphocytes also express TLRs and function as costimulatory receptors to upregulate proliferation and cytokine production in response to specific agonists.. In this study, we show that naïve CD4(+) and CD8(+) T cells express detectable levels of TLR4 and TLR9 and that increase after the induction of EAE in SJL/J and C57BL/6 mice by immunization with PLPp139-151 and MOGp35-55 antigen, respectively. It is interesting to note that in vivo treatment with 15d-PGJ2 or curcumin results in a significant decrease in TLR4 and TLR9 expression in CD4(+) and CD8(+) T cells in association with the amelioration of EAE.. Although the exact mechanisms are not known, the modulation of TLR expression in T lymphocytes by 15d-PGJ(2) and curcumin suggests new therapeutic targets in the treatment of T cell-mediated autoimmune diseases.

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Curcumin; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Freund's Adjuvant; Glycoproteins; Humans; Immunization; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Myelin Proteolipid Protein; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Prostaglandin D2; Toll-Like Receptor 4; Toll-Like Receptor 9

Phagocytosis is necessary to eliminate the hematoma after intracerebral hemorrhage (ICH); however, release of proinflammatory mediators and free radicals during phagocyte activation is toxic to neighboring cells, leading to secondary brain injury. Promotion of phagocytosis in a timely and efficient manner may limit the toxic effects of persistent blood products on surrounding tissue and may be important for recovery after ICH.. Intrastriatal blood injection in rodents and primary microglia in culture exposed to red blood cells were used to model ICH and to study mechanisms of hematoma resolution and phagocytosis regulation by peroxisome proliferator-activated receptor gamma (PPARgamma) in microglia/macrophages.. Our study demonstrated that the PPARgamma agonist, rosiglitazone, promoted hematoma resolution, decreased neuronal damage, and improved functional recovery in a mouse ICH model. Microglia isolated from murine brains showed more efficient phagocytosis in response to PPARgamma activators. PPARgamma activators significantly increased PPARgamma-regulated gene (catalase and CD36) expression, whereas reducing proinflammatory gene (tumor necrosis factor-alpha, interleukin-1beta, matrix metalloproteinase-9, and inducible nitric oxide synthase) expression, extracellular H(2)O(2) level, and neuronal damage. Phagocytosis by microglia was significantly inhibited by PPARgamma gene knockdown or neutralizing anti-CD36 antibody, whereas it was enhanced by exogenous catalase.. PPARgamma in macrophages acts as an important factor in promoting hematoma absorption and protecting other brain cells from ICH-induced damage.

Topics: Animals; Animals, Newborn; CD36 Antigens; Cells, Cultured; Cerebral Hemorrhage; Cytokines; Disease Models, Animal; Enzyme Activators; Erythrocytes; Hematoma; Hydrogen Peroxide; Male; Mice; Mice, Inbred C57BL; Microglia; Neurons; Nitric Oxide Synthase Type II; Phagocytosis; PPAR gamma; Prostaglandin D2; Severity of Illness Index; Time Factors

In macrophages, peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to be important for differentiation, and it serves as a negative regulator of activation. Major trauma/injury causes a dramatic host response that disrupts cellular immune homeostasis and initiates an inflammatory cascade that predisposes the injured host to subsequent infections. In prior studies using a murine trauma model consisting of femur fracture and hemorrhage, splenic macrophages from traumatized mice had significantly enhanced LPS-induced cyclooxygenase enzyme (subtype 2) and iNOS production as well as elevated levels of inflammatory cytokines at 1 week after injury compared with uninjured controls. These up-regulated cellular responses corresponded to increased mortality when animals were challenged with LPS or Candida. In the current study, we used the injury model to determine the effect of treatment of injured mice with the endogenous PPARgamma ligand 15-deoxy-Delta(12-, 14)-PGJ2 (15d-PGJ2). It was found that in vivo 15d-PGJ2 treatment significantly reduced the levels of inflammatory mediators produced by splenic macrophages 7 days after injury. The mechanism of inhibition is dependent on PPARgamma because concomitant treatment of animals with the PPARgamma antagonist GW9662 reversed the inhibitory effect of 15d-PGJ2. Endogenous PPARgamma modulated activation of LPS-induced p38 mitogen-activated protein kinase. Furthermore, treatment of injured mice with 15d-PGJ2 conferred a significant survival advantage after infectious challenge induced by cecal ligation and puncture. Thus, this PPARgamma ligands significantly attenuate the postinjury inflammatory response and improve survival after infectious challenge.

Topics: Animals; Disease Models, Animal; Female; Macrophage Activation; Macrophages; Mice; Mice, Inbred BALB C; PPAR gamma; Prostaglandin D2; Wounds and Injuries

Dried roots of the plants Acanthopanax senticosus, Angelica sinensis and Scutellaria baicalensis are used in traditional oriental medicine and reportedly possess anti-inflammatory properties. Using the murine air pouch model of inflammation, we investigated the efficacy and mode of action of an extract from these three plants in crystal-induced inflammation. Air pouches were raised on the backs of 8-week-old BALB/c mice. Mice were fed 100 mg/kg body weight of root extracts (A. senticosus:A. sinensis:S. baicalensis mixed in a ratio of 5:4:1 by weight) or vehicle only on days 3-6. Inflammation was elicited on day 6 by injecting 2 mg of monosodium urate (MSU) crystals into the pouch. Neutrophil density and IL-6 and TNF-alpha mRNA levels were determined in the pouch membrane, and the leukocyte count and IL-6, prostaglandin E2 (PGE2) and prostaglandin D2 (PGD2) levels were determined in the pouch exudate. Treatment with the root extracts led to a reduction in all inflammatory parameters: the leukocyte count in the pouch exudate decreased by 82%; the neutrophil density in the pouch membrane decreased by 68%; IL-6 and TNF-alpha mRNA levels in the pouch membrane decreased by 100%; the IL-6 concentration in the pouch fluid decreased by 50%; and the PGE2 concentration in the pouch fluid decreased by 69%. Remarkably, the concentration of the potentially anti-inflammatory PGD2 rose 5.2-fold in the pouch exudate (p < 0.005), which led to a normalization of the PGD2:PGE2 ratio. A 3.7-fold rise in hematopoietic PGD synthase (h-PGDS) mRNA paralleled this rise in PGD2 (p = 0.01). Thus, the root extracts diminished MSU crystal-induced inflammation by reducing neutrophil recruitment and expression of pro-inflammatory factors and increasing the level of the potentially anti-inflammatory PGD2. These results support a need for further studies of the efficacy of these extracts in the treatment of inflammatory arthropathies and suggest elevation of PGD2 levels as a novel mechanism for an anti-inflammatory agent.

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Gouty; Dinoprostone; Disease Models, Animal; Eleutherococcus; Exudates and Transudates; Female; Gene Expression; Interleukin-6; Leukocyte Count; Medicine, East Asian Traditional; Mice; Mice, Inbred BALB C; Neutrophils; Plant Extracts; Plant Roots; Plants, Medicinal; Prostaglandin D2; RNA, Messenger; Tumor Necrosis Factor-alpha; Uric Acid

Topics: Acute Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Proliferation; Chronic Disease; Disease Models, Animal; Gene Expression Regulation; Humans; Inflammation; Lipid Metabolism; Lipids; Lymphocytes; Mice; Models, Biological; Peritonitis; Prostaglandin D2; Time Factors

Stroke triggers an inflammatory cascade which contributes to a delayed cerebral damage, thus implying that antiinflammatory strategies might be useful in the treatment of acute ischaemic stroke. Since two unrelated peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, the thiazolidinedione rosiglitazone (RSG) and the cyclopentenone prostaglandin 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2), have been shown to possess antiinflammatory properties, we have tested their neuroprotective effects in experimental stroke. Rosiglitazone or 15d-PGJ2 were administered to rats 10 mins or 2 h after permanent middle cerebral artery occlusion (MCAO). Stroke outcome was evaluated by determination of infarct volume and assessment of neurological scores. Brains were collected for protein expression, gene array analyses and gene shift assays. Our results show that both compounds decrease MCAO-induced infarct size and improve neurological scores. At late times, the two compounds converge in the inhibition of MCAO-induced brain expression of inducible NO synthase and the matrix metalloproteinase 9. Interestingly, at early times, complementary DNA microarrays and gene shift assays show that different mechanisms are recruited. Analysis of early nuclear p65 and late cytosolic IkappaBalpha protein levels shows that both compounds inhibit nuclear factor-kappaB signalling, although at different levels. All these results suggest both PPARgamma-dependent and independent pathways, and might be useful to design both therapeutic strategies and prognostic markers for stroke.

Topics: Animals; Anti-Inflammatory Agents; Cyclooxygenase 2; Disease Models, Animal; Drug Administration Schedule; Electrophoresis, Gel, Two-Dimensional; Gene Expression Regulation, Enzymologic; I-kappa B Proteins; Infarction, Middle Cerebral Artery; Male; Matrix Metalloproteinase 9; Neuroprotective Agents; NF-kappa B; NF-KappaB Inhibitor alpha; Nitrates; Nitric Oxide Synthase Type II; Nitrites; Oligonucleotide Array Sequence Analysis; PPAR gamma; Prostaglandin D2; Rats; Rats, Inbred F344; Reverse Transcriptase Polymerase Chain Reaction; Rosiglitazone; Thiazolidinediones; Time Factors

Hematopoietic prostaglandin D synthase (PGDS) is a key enzyme involved in production of the PGD and J series, which have various role in inflammation and immunity. We evaluated the effect of treatment with 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) or the injection of prostaglandin D(2) synthase (PGDS) cDNA expressing-retrovirally transfected fibroblasts on bleomycin (BLM)-induced scleroderma-like skin sclerosis. Daily injection of BLM (30 microg) for 4 weeks induced histological evidence of dermal sclerosis in C3H mice. We examined the effect of injection of 15d-PGJ(2) (30 ng twice a day) or PGDS expressing-retrovirally transfected fibroblast on BLM-induced dermal sclerosis. Administration of 15d-PGJ(2) (a nonenzymatic metabolite of PGD(2)) injection of PGDS cDNA-expressing fibroblasts significantly reduced dermal sclerosis, the hydroxyproline content, and dermal thickness. Moreover, 15-d PGJ2 down-regulation of the expression of transforming growth factor beta(1) and connective tissue growth factor which had been induced by BLM. Mast cells were also increased in the skin by BLM injection and there was prominent degranulation of these mast cells along with elevated plasma histamine levels. 15-d PGJ(2) and PGDS-expressing cells also suppressed degranulation of cultured mast cells and histamine release by these cells. These results show that 15-d PGJ(2) and PGDS-expressing cells can prevent experimental skin sclerosis induced by BLM and raise the possibility of therapeutic approaches targeting of PPARgamma for the skin lesion of scleroderma.

Topics: Animals; Bleomycin; Connective Tissue Growth Factor; Disease Models, Animal; Female; Fibroblasts; Histamine Release; Hydroxyproline; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Intramolecular Oxidoreductases; Lipocalins; Mast Cells; Mice; Mice, Inbred C3H; Prostaglandin D2; RNA, Messenger; Scleroderma, Systemic; Sclerosis; Skin; Transfection

As an attempt to find bioactive medicinal herbs exerting anti-asthmatic activity, the effects of an ethanol extract from the parts of Saururus chinensis were evaluated in both in vitro and in vivo. The ethanol extract of S. chinensis (ESC) inhibited generation of the cyclooxygenase-2 (COX-2) dependent phases of prostaglandin D(2) in bone marrow-derived mast cells in a concentration-dependent manner with an IC(50) value of 14.3 microg/ml. ESC also inhibited leukotriene C(4) production with an IC(50) value of 0.3 microg/ml. This demonstrates that ESC has COX-2/5-lipoxygenase dual inhibitory activity. In addition, this compound inhibited degranulation reaction in a dose dependent manner, with an IC(50) value of 1.3 microg/ml. An ovalbumin induced mouse asthmatic animal model was used to determine its in vivo anti-asthmatic activity. The oral administration (50-200 mg/kg) of ESC reduced the number of infiltrated eosinophil in a bronchoalveolar lavage fluid. Furthermore, ESC (100 mg/kg) inhibited the eotaxin and IL-4 mRNA expression levels. These results suggest that the anti-asthmatic activity of S. chinensis might in part occur via the inhibition of eicosanoid generation, degranulation as well as the down regulation of IL-4 and eotaxin mRNA expression.

Topics: Animals; Anti-Asthmatic Agents; Arachidonate 5-Lipoxygenase; Asthma; Bronchoalveolar Lavage Fluid; Cell Count; Cell Degranulation; Cyclooxygenase 2; Disease Models, Animal; Dose-Response Relationship, Drug; Eosinophils; Ethanol; Female; Male; Mast Cells; Mice; Mice, Inbred BALB C; Mice, Inbred ICR; Ovalbumin; Plant Components, Aerial; Plant Extracts; Prostaglandin D2; Saururaceae

We examined the role of cyclooxygenase-2 in the development of ischemic tolerance induced by cortical spreading depression against transient, focal brain ischemia. Cortical spreading depression was continuously induced for 2 h with topical KCl (13+/-1 depolarizations/2 h) in male Wistar rats. At 1, 2, 3, 4, and 5 days following recovery, the middle cerebral artery was transiently occluded for 120 min. Four days later, the animals were killed and infarct volume was determined. Additionally, cyclooxygenase-2 levels in the cerebral cortex and 15 deoxy-Delta(12, 14) PGJ2 levels in cerebrospinal fluid were determined at these times with Western blotting and immunoassay, respectively. Infarct volume was reduced compared with non-cortical spreading depression control animals (274.3+/-15.3 mm3) when cortical spreading depression was performed 3 and 4 days before middle cerebral artery occlusion (163.9+/-14.2 mm3, 154.9+/-14.2 mm3) but not at 1, 2 and 5 days (280.4+/-17.3 mm3, 276.3+/-16.9 mm3 and 268.5+/-17.3 mm3). Cyclooxygenase-2 levels increased most dramatically starting at 2 days, peaked at 3 days, and started to return toward baseline at 4 days after cortical spreading depression. 15 Deoxy-Delta(12, 14) PGJ2 levels increased from 134.7+/-83 pg/ml at baseline to 718+/-98 pg/ml at 3 days. Administration of N-[2-cyclohexyloxy-4-nitrophenyl] methanesulphonamide (10 mg/kg, i.v.), a selective cyclooxygenase-2 inhibitor, at 1 h prior to middle cerebral artery occlusion in cortical spreading depression preconditioned animals did not affect infarct volume (162.6+/-62.1 mm3). However, administration of N-[2-cyclohexyloxy-4-nitrophenyl] methanesulphonamide given three times prior to middle cerebral artery occlusion prevented the reduced infarct volume induced by cortical spreading depression preconditioning (272.9+/-63.2 mm3). Administration of L-nitro-arginine methyl ester (4 mg/kg, i.v.) prior to cortical spreading depression blocked increases in cyclooxygenase-2 normally seen at 3 and 4 days. We conclude that NO-mediated cyclooxygenase-2 upregulation by cortical spreading depression protects the brain against ischemic damage.

Topics: Animals; Cerebral Cortex; Cerebral Infarction; Cortical Spreading Depression; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cytoprotection; Disease Models, Animal; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Ischemic Preconditioning; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Potassium Chloride; Prostaglandin D2; Rats; Rats, Wistar; Up-Regulation

Prostaglandins (PGs) are potent proinflammatory mediators generated through arachidonic acid metabolism by cyclooxygenase-1 and -2 (COX-1 and COX-2) in response to different stimuli and play an important role in modulating the inflammatory responses in a number of conditions, including allergic airway inflammation. Thymoquinone (TQ) is the main active constituent of the volatile oil extract of Nigella sativa seeds and has been reported to have anti-inflammatory properties. We examined the effect of TQ on the in vivo production of PGs and lung inflammation in a mouse model of allergic airway inflammation. Mice sensitized and challenged through the airways with ovalbumin (OVA) exhibited a significant increase in PGD2 and PGE2 production in the airways. The inflammatory response was characterized by an increase in the inflammatory cell numbers and Th2 cytokine levels in the bronchoalveolar lavage (BAL) fluid, lung airway eosinophilia and goblet cell hyperplasia, as well as the induction of COX-2 protein expression in the lung. Intraperitoneal injection of TQ for 5 days before the first OVA challenge attenuated airway inflammation as demonstrated by the significant decrease in Th2 cytokines, lung eosinophilia, and goblet cell hyperplasia. This attenuation of airway inflammation was concomitant to the inhibition of COX-2 protein expression and PGD2 production. However, TQ had a slight inhibitory effect on COX-1 expression and PGE2 production. These findings suggest that TQ has an anti-inflammatory effect during the allergic response in the lung through the inhibition of PGD2 synthesis and Th2-driven immune response.

Topics: Allergens; Animals; Anti-Inflammatory Agents; Benzoquinones; Bronchial Hyperreactivity; Cyclooxygenase 1; Cyclooxygenase 2; Cytokines; Dinoprostone; Disease Models, Animal; Female; Gene Expression Regulation; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Prostaglandin D2; Th2 Cells

We examined the involvement of cyclooxygenase (COX)-1 and COX-2 on mechanical scratching-induced prostaglandins (PGs) production in the skin of mice. The dorsal regions of mice were scratched using a stainless brush. COXs expressions in the skin were analyzed using real-time PCR and Western blotting. The effect of acetylsalicylic acid (ASA) on the ability of PGs production were determined based on skin PGs level induced by arachidonic acid (AA) application. Mechanical scratching increased PGD2, PGE2, PGI2 and PGF(2 alpha). COX-1 was constitutively expressed and COX-2 expression was enhanced by scratching. Intravenous administration of ASA inhibited PGs biosynthesis in the normal skin. PGs levels of the skin 6h after ASA administration (ASA 6 h) were almost equal to those of the skin 10 min after ASA administration (ASA 10 min). In the scratched skin, AA-induced PGE2 and PGI2 of ASA 6 h were significantly higher than those of ASA 10 min. The skin PGD2 and PGF(2 alpha) of ASA 10 min were almost same to those of ASA 6 h. In the normal skin of COX-1-deficient mice, skin PGD2 level was lower than that of wild-type mice, although PGE2, PGI2 and PGF(2 alpha) levels were almost equal to those of wild type. In the scratched skin of COX-1-deficient mice, PGD2, PGE2, PGI2 and PGF(2 alpha) levels were lower than those of wild-type mice. These results suggested that cutaneous PGD2 could be mainly produced by COX-1, and PGE2 and PGI2 could be produced by COX-1 and COX-2, respectively, in mice.

Topics: Animals; Aspirin; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Disease Models, Animal; Epoprostenol; Mice; Prostaglandin D2; Prostaglandins; Pruritus; Skin; Up-Regulation

PGD(2) plays roles in allergic inflammation via specific receptors, the PGD receptor designated DP and CRTH2 (chemoattractant receptor homologous molecule expressed on Th2 cells). We generated mutant mice carrying a targeted disruption of the CRTH2 gene to investigate the functional roles of CRTH2 in cutaneous inflammatory responses. CRTH2-deficent mice were fertile and grew normally. Ear-swelling responses induced by hapten-specific IgE were less pronounced in mutant mice, giving 35-55% of the responses of normal mice. Similar results were seen in mice treated with a hemopoietic PGD synthase inhibitor, HQL-79, or a CRTH2 antagonist, ramatroban. The reduction in cutaneous responses was associated with decreased infiltration of lymphocytes, eosinophils, and basophils and decreased production of macrophage-derived chemokine and RANTES at inflammatory sites. In models of chronic contact hypersensitivity induced by repeated hapten application, CRTH2 deficiency resulted in a reduction by approximately half of skin responses and low levels (63% of control) of serum IgE production, although in vivo migration of Langerhans cells and dendritic cells to regional lymph nodes was not impaired in CRTH2-deficient mice. In contrast, delayed-type hypersensitivity to SRBC and irritation dermatitis in mutant mice were the same as in wild-type mice. These findings indicate that the PGD(2)-CRTH2 system plays a significant role in chronic allergic skin inflammation. CRTH2 may represent a novel therapeutic target for treatment of human allergic disorders, including atopic dermatitis.

Topics: Animals; Chronic Disease; Dermatitis, Allergic Contact; Disease Models, Animal; Female; Immunoglobulin E; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin

Clinical and animal studies indicate that stress can contribute to the onset and/or the worsening of the course of inflammatory bowel diseases (IBD). In a model (inmobilisation stress for 6 h.) in rats it has been demonstrated that stress increases colonic inflammatory damage, as well as antiinflammatory prostaglandins and of the nuclear receptor PPARgamma. This inflammation is followed by an increase in the permeability of the colonic mucosa barrier and a decrease in IgA levels. All these parameters contribute to the bacterial traslocation to other organs. PPARgamma agonists drugs prevent these inflammatory changes as well as the disfunction of the mucosal colonic barrier, which suggests its use in the worsening episodes of IBD produced by stress.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bacterial Translocation; Colitis, Ulcerative; Disease Models, Animal; Humans; Immobilization; Immunoglobulin A; Inflammatory Bowel Diseases; PPAR gamma; Prostaglandin D2; Prostaglandins; Rats; Rosiglitazone; Stress, Psychological; Thiazolidinediones; Time Factors

Prostaglandin E(2) and D(2) (PGE(2) and PGD(2)) production and cyclooxygenase-2 (COX-2) expression during the resolution of acute and chronic gastric inflammatory lesions in Wistar rats have been investigated. Differences between ibuprofen, nonselective COX inhibitor, and rofecoxib, specific COX-2 inhibitor, on the development of the induced responses were also analysed. In an acute model, by instillation of HCL, the greatest injury was observed early with a rapid and progressive restoration. Maximal up-regulation of COX-2 protein was detected at 6 h and was accompanied by increase of PGE(2) synthesis but not PGD(2). Both drugs stimulated COX-2 expression in accordance to their capacity of inhibiting this enzymatic activity, driving to delay in the healing. In a chronic model, by acetic acid-induced gastric ulcers, COX-2 was expressed at 7 days and was also associated with PGE(2) increase. Ibuprofen and rofecoxib also augmented COX-2 protein and inhibited PGE(2) levels. However, PGD(2) production was augmented when none signal of COX-2 protein could be detected. Together, this study confirms the role played by COX-2 enzyme in the resolution of acute and chronic gastric inflammatory process, PGE(2) being the principal product. The antiinflammatory effect of nonsteroidal antiinflammatory drugs (NSAIDs) could be mediated not only through the inhibition of COX activity but also through the induction of antiinflammatory PGs production-such as PGD(2)-although further studies would be needed to clarify the mechanisms of this activity and the possible implicated processes.

Topics: Acetic Acid; Acute Disease; Animals; Chronic Disease; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; Hydrochloric Acid; Ibuprofen; Lactones; Male; Membrane Proteins; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Stomach Ulcer; Sulfones

Acute lung injury (ALI) is a disease process that is characterized by diffuse inflammation in the lung parenchyma. Recent studies demonstrated that cyclooxygenase-2 (COX-2) induced at the late phase of inflammation aids in the resolution of inflammation by generating 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2). Transcription factor Nrf2 is activated by electrophiles and exerts antiinflammatory effects by inducing the gene expression of antioxidant and detoxification enzymes.. Because 15d-PGJ2 is an endogenous electrophile, we hypothesized that it protects against ALI by activating Nrf2.. To test this hypothesis, we generated a reversible ALI model by intratracheal injection of carrageenin, an inducer of acute inflammation, whose stimulation has been known to induce COX-2.. We found that ALI induced by carrageenin was markedly exacerbated in Nrf2-knockout mice, compared with wild-type mice. Analysis of bronchoalveolar lavage fluids also revealed that the magnitude and the duration of acute inflammation, indicated by albumin concentration and the number of neutrophils, were significantly enhanced in Nrf2-knockout mice. Treatment of wild-type mice with NS-398, a selective COX-2 inhibitor, significantly exacerbated ALI to the level of Nrf2-knockout mice. In the lungs of NS-398-treated wild-type mice, both the accumulation of 15d-PGJ2 and the induction of Nrf2 target antioxidant genes were significantly attenuated. Exogenous administration of 15d-PGJ2 reversed the exacerbating effects of NS-398 with the induction of antioxidant genes.. These results demonstrated in vivo that 15d-PGJ2 plays a protective role against ALI by exploiting the Nrf2-mediated transcriptional pathway.

Topics: Animals; Carrageenan; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; DNA-Binding Proteins; Macrophages; Mice; Mice, Inbred BALB C; NF-E2-Related Factor 2; Nitrobenzenes; Pneumonia; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Respiratory Distress Syndrome; Sulfonamides; Trans-Activators

Topics: Animals; Disease Models, Animal; Immunologic Factors; Mice; Multiple Organ Failure; Pentoxifylline; PPAR gamma; Prostaglandin D2; Vasodilator Agents; Zymosan

This study focused on the regulation of prostaglandin (PG) production in diabetes-impaired wound tissue. Cyclooxygenase (COX)-1 and -2 expression and activity were severely dysregulated in chronic wounds of diabetic ob/ob mice. Those wounds were characterized by a reduced expression of COX-1 and the presence of strongly elevated levels of COX-2 when compared with conditions observed in healthy animals. Resolution of the diabetic and impaired wound-healing phenotype by systemic administration of leptin into ob/ob mice increased COX-1 expression in wound margin keratinocytes and decreased COX-2 expression in inner wound areas to levels found in wild-type animals. Notably, improved wound healing was characterized by a marked increase in PGE2/PGD2 biosynthesis that colocalized with induced COX-1 in new tissue at the margin of the wound. COX-2 expression did not significantly contribute to PGE2/PGD2 production in impaired wound tissue. Accordingly, only late wound tissue from SC-560-treated (selective COX-1 inhibitor) but not celecoxib-treated (selective COX-2 inhibitor) ob/ob mice exhibited a severe loss in PGE2, PGD2, and prostacyclin at the wound site, and this change was associated with reduced keratinocyte numbers in the neo-epithelia. These data constitute strong evidence that a dysregulation of COX-1-coupled prostaglandin contributes to diabetes-impaired wound healing.

Topics: Animals; Cyclooxygenase 1; Cyclooxygenase 2; Diabetes Mellitus, Type 2; Dinoprostone; Disease Models, Animal; Inflammation; Leptin; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Recombinant Proteins; Wound Healing; Wounds and Injuries

In both type 2 diabetes and insulin-resistance syndromes, hyperglycemia and advanced glycation end products (AGEs) activate the transcription factor nuclear factor-kappaB (NF-kappaB) through a mechanism that partly involves the generation of reactive oxygen species (ROS). The contribution of hyperinsulinemia in this sequence has not been completely elucidated. In this work we investigated the actions of insulin and PPAR-gamma on the stimulation by AGEs of NF-kappaB protein expression in cultured aortic vascular smooth-muscle cells (VSMCs) from non-insulin-dependent diabetic rats and nondiabetic rats. The expression of proteins was evaluated with the use of Western immunoblotting. Incubations (24 hours) of VSMCs with 10 to 100 microg/mL glycated bovine serum albumin (AGE- BSA) increased NF-kappaB protein expression in both models. PPAR-gamma protein expression was only enhanced at concentrations of 500 to 1000 microg/mL (AGE-BSA). In the presence of insulin (10-100 nmol/L), the stimulation of NF-kappaB protein expression by AGE-BSA (100 microg/mL) was decreased, whereas the expression of PPAR-gamma, protein was enhanced. 15-Deoxyprostaglandin J2, a direct activator of PPAR-gamma, decreased AGE-BSA-stimulated NF-kappaB expression. These findings suggest that insulin decreases the incidence of alterations in VSMCs induced by AGEs through the reduction of NF-kappaB and an increase in PPAR-gamma protein expression (as far as the model could be extrapolated to in vivo situations). These data may help justify current therapeutic approaches involving the use of insulin and PPAR-gamma agonists.

Topics: Animals; Cattle; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Glycated Serum Albumin; Glycation End Products, Advanced; Glycosylation; Insulin; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NF-kappa B; PPAR gamma; Prostaglandin D2; Rats; Rats, Wistar; Serum Albumin; Serum Albumin, Bovine

We investigated whether prostaglandins (PGs), proinflammatory mediators implicated in excitatory activity, are involved in Shigella-related seizures. Pretreatment with S. dysenteriae sonicate (2LD(50)) enhanced mice response to pentylenetetrazole-induced seizures, without increase of brain concentrations of PGE(2), PGD(2) or PGF(2alpha). Preinjection of NS-398, an inhibitor of cyclooxygenase-2, before treatment with Shigella sonicate, had no effect on seizures. The anticonvulsive PGD(2) increased after injection of 8 LD(50) of Shigella sonicate, which did not enhance seizures (32 pg/mg vs 26 pg/ml, p=0.0063). The findings indicate that PGs are not involved in the enhanced seizure response after exposure to Shigella. However, induction of PGD(2) may play an inhibitory role.

Topics: Animals; Chi-Square Distribution; Cyclooxygenase Inhibitors; Dinoprost; Dinoprostone; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Enzyme-Linked Immunosorbent Assay; Lethal Dose 50; Male; Mice; Mice, Inbred ICR; Nitrobenzenes; Pentylenetetrazole; Prostaglandin D2; Prostaglandins; Seizures; Shigella dysenteriae; Sulfonamides

Colitis markedly increases the risk of developing colon cancer, but the underlying mechanisms are not fully understood. In a rat model of colitis, alterations in epithelial secretion, proliferation, and barrier function persist long after healing has occurred. In the present study, we examined whether rats that have recovered from a bout of colitis are more susceptible to preneoplastic lesions and whether this susceptibility is mediated by cyclooxygenase (COX)-2-derived prostaglandin (PG) D2. Colitis was induced by intracolonic administration of trinitrobenzenesulfonic acid. Six weeks later, weekly treatment with the carcinogen azoxymethane was initiated. Postcolitis rats exhibited significantly more aberrant crypt foci after azoxymethane treatment than controls. The postcolitis rats also exhibited markedly increased colonic PGD2 synthesis and elevated COX-2, H-PGD synthase, and beta-catenin expression. Treatment for 1 week with a selective COX-2 inhibitor or with a selective PGD2 receptor (DP1) antagonist significantly reduced susceptibility of postcolitis rats to aberrant crypt foci development, beta-catenin expression, and mucosal thickness. The results from this animal model suggest that prolonged elevation of COX-2-derived PGD2 synthesis after resolution of colitis may contribute significantly to colitis-associated increases in colon cancer incidence. PGD2 may therefore represent a rational target for therapies directed at reducing the incidence of colitis-associated colorectal cancer.

Topics: Animals; Azoxymethane; beta Catenin; Colitis; Colon; Colorectal Neoplasms; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Disease Susceptibility; Intramolecular Oxidoreductases; Lipocalins; Male; Prostaglandin D2; Rats; Rats, Wistar; Receptors, Immunologic; Receptors, Prostaglandin; Trinitrobenzenesulfonic Acid

Fever is an important part of the host defense response, yet fever can be detrimental if it is uncontrolled. We provide the first evidence that 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), an endogenous ligand for peroxisome proliferator-activated receptor gamma (PPARgamma), can attenuate the febrile response to lipopolysaccharide (LPS) in rats via an action on the brain. Furthermore, we show that PPARgamma is expressed in the hypothalamus, an important locus in the brain for fever generation. In addition, 15d-PGJ2 and its synthesizing enzyme (PGD2 synthase) were present in rat cerebrospinal fluid, and their levels were enhanced in response to systemic injection of LPS. The antipyretic effect of 15d-PGJ2 was associated with reduction in LPS-stimulated cyclooxygenase-2 expression in the hypothalamus but not in p44/p42 mitogen-activated protein kinase phosphorylation or in the expression of the PPARgamma. Thus it is likely that there is a parallel induction of an endogenous prostanoid pathway in the brain capable of limiting deleterious actions of the proinflammatory prostaglandin E2-dependent pathway.

Topics: Analgesics, Non-Narcotic; Animals; Body Temperature; Brain; Cyclooxygenase 2; Disease Models, Animal; Fever; Hypothalamus; Intramolecular Oxidoreductases; Isoenzymes; Lipocalins; Lipopolysaccharides; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Transcription Factors

The mobilization of Langerhans cells (LCs) from epithelia to the draining lymph nodes is an essential process to initiate primary immune responses. We have recently shown that in mice, PGD2 is a potent inhibitor of epidermal LC emigration. In this study, we demonstrate that activation of the D prostanoid receptor 1 (DP1) impedes the TNF-alpha-induced migration of human LCs from skin explants and strongly inhibits the chemotactic responses of human LC precursors and of maturing LCs to CC chemokine ligands 20 and 19, respectively. Using a murine model of atopic dermatitis, a chronic Th2-type allergic inflammatory disease, we demonstrate that the potent DP1 agonist BW245C dramatically decreases the Ag-specific T cell activation in the skin draining lymph nodes and markedly prevents the skin lesions following repeated epicutaneous sensitization with OVA. Interestingly, analysis of the local response indicates that BW245C treatment strongly reduces the recruitment of inflammatory cells into the dermis and disrupts the Th1/Th2 balance, probably through the increased production of the immunoregulatory cytokine IL-10, in the skin of sensitized mice. Taken together, our results suggest a new function for DP1 in the regulation of the immune and inflammatory responses. We propose that DP1 activation by specific agonists may represent a strategy to control cutaneous inflammatory Th2-associated diseases.

Topics: Adjuvants, Immunologic; Animals; Cell Migration Inhibition; Chemotaxis, Leukocyte; Culture Techniques; Dermatitis, Atopic; Disease Models, Animal; Down-Regulation; Epitopes, T-Lymphocyte; Female; Growth Inhibitors; Humans; Langerhans Cells; Lymph Nodes; Mice; Mice, Inbred BALB C; Mice, Transgenic; Ovalbumin; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; RNA, Messenger; T-Lymphocyte Subsets; Th1 Cells; Th2 Cells; Up-Regulation

Racemic formoterol is an equimolar mixture of (R,R)- and (S,S)-formoterol. Several studies have shown (S,S)-formoterol to have proinflammatory effects. We previously reported that (S)-albuterol increased the secretion of histamine and interleukin (IL)-4 in murine mast cells. We thus hypothesized that (S,S)-formoterol promotes asthma by enhancing IL-4 production in mast cells of the asthmatic airway.. Murine and human mast cells were stimulated by high affinity IgE receptor (Fc epsilon RI) cross-linking or with phorbol myristate acetate/calcium ionophore A23187 (PMA/A23187). Jurkat T cells were stimulated with PMA. Cells were pretreated with either (R,R)- or (S,S)-formoterol. Ovalbumin (OVA)-sensitized BALB/c mice were pretreated with (R,R)- or (S,S)-formoterol before each intranasal OVA challenge for 10 days. Bronchoalveolar lavage fluid was obtained from the mice. The levels of IL-4, histamine and PGD(2) were measured. Early and late allergic responses (EAR and LAR, respectively) to OVA challenge and airway hyperresponsiveness (AHR) were measured.. (S,S)-formoterol enhanced the production of IL-4, histamine, and PGD(2) in mast cells, whereas (R,R)-formoterol had no effect. Neither (S,S)- nor (R,R)-formoterol had effect on IL-4 production in Jurkat T cells. In OVA-challenged mice, (S,S)-formoterol increased IL-4 secretion, whereas (R,R)-formoterol had no effect. Finally, (S,S)-formoterol enhanced the inflammatory changes in the peribronchial and perivascular areas without affecting EAR, LAR or AHR, whereas (R,R)-formoterol reduced EAR, LAR and AHR as well as cellular infiltration in the lung tissue of these mice.. (S,S)-formoterol may exert adverse effects in asthma control by activating mast cells to produce proinflammatory mediators such as IL-4.

Topics: Animals; Asthma; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchodilator Agents; Disease Models, Animal; Ethanolamines; Formoterol Fumarate; Histamine Release; Histocytochemistry; Humans; Interleukin-4; Jurkat Cells; Lung; Male; Mast Cells; Methacholine Chloride; Mice; Mice, Inbred BALB C; Prostaglandin D2; Stereoisomerism; T-Lymphocytes

PGD2, a lipid mediator released from mast cells, is known to participate in allergic reactions. However, the mechanism by which PGD2 contributes to such reactions remains unclear. We established a novel experimental model of asthma that permitted direct assessment of the role of PGD2 in airway inflammation. Antigen-sensitized mice were exposed to aerosolized prostaglandin D2 (PGD2) 1 d before challenge with low-dose aerosolized antigen. Not only the numbers of eosinophils, lymphocytes, and macrophages but also the levels of IL-4 and IL-5 in bronchoalveolar lavage fluid were higher in PGD2-pretreated mice than in control mice. The expression of macrophage-derived chemokine (MDC), a chemoattractant for Th2 cells, was greater in PGD2-pretreated mice than in control. Injection of anti-MDC antibody into PGD2-pretreated mice markedly inhibited inflammatory cell infiltration as well as Th2 cyto-kine production after antigen challenge. These results indicate that PGD2 accelerates Th2 type inflammation by induction of MDC. Our results suggest that this mechanism may play a key role in the development of human asthma and that MDC might be a target molecule for therapeutic intervention.

Topics: Animals; Antigens; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Cell Line; Chemokine CCL22; Chemokines; Chemokines, CC; Cytokines; Disease Models, Animal; Humans; Lung; Male; Mice; Mice, Inbred BALB C; Prostaglandin D2; Spleen; Th2 Cells

Hematopoietic prostaglandin D synthase (H-PGDS) is a key enzyme in the production of prostaglandin D and its J series metabolites. We evaluated the antiinflammatory effect of retrovirally transfected H-PGDS in order to investigate the role of H-PGDS in monosodium urate monohydrate (MSU) crystal-induced acute inflammation.. Expression of endogenous PGDS in a murine air-pouch model of MSU crystal-induced acute inflammation was determined by real-time polymerase chain reaction. H-PGDS complementary DNA (cDNA) was retrovirally transfected into C57BL/6J fibroblasts, and the cells were designated as C57-PGDS cells. Production of prostaglandins by C57-PGDS cells was measured by enzyme immunoassay. The effect of C57-PGDS cells on crystal-induced inflammation was investigated.. Injection of the crystals caused a rapid decrease in H-PGDS expression by infiltrating cells and by the soft tissues around the air pouches. In contrast, expression of interleukin-1beta (IL-1beta) and macrophage inflammatory protein 2 (MIP-2) as well as cellular infiltration were significantly increased during the early stage of inflammation. C57-PGDS cells, but not control cells, produced an increased amount of PGD(2) in vitro, but suppressed production of PGE(2). Injection of C57-PGDS cells into air pouches inhibited cellular infiltration and MIP-2 and IL-1beta expression.. In this murine air-pouch model of MSU crystal-induced inflammation, retrovirally transfected H-PGDS cDNA could reduce cellular infiltration, at least partly by inhibiting MIP-2 and IL-1beta. These findings suggest that gene therapy with H-PGDS may be useful for treating inflammatory diseases.

Topics: Acute Disease; Animals; Arthritis, Gouty; Cell Line, Tumor; Chemokine CXCL2; Chemokines; Crystallization; Disease Models, Animal; Fibroblasts; Gene Expression Regulation, Enzymologic; Genetic Therapy; Interleukin-1; Intramolecular Oxidoreductases; Leukemia, Basophilic, Acute; Lipocalins; Macrophages; Male; Mice; Mice, Inbred C57BL; Prostaglandin D2; Rats; Retroviridae; Transfection; Uric Acid

In this study, we have evaluated the efficacy of dosmalfate, a new flavonoid derivative compound, for the prevention and treatment of experimental colitis. To induce colitis, BALB/c mice received 5% dextran sulphate sodium (DSS) in their drinking water continuously for 7 days. Colitis was quantified by a clinical damage score, colon length, weight loss, stool consistency and rectal bleeding. Inflammatory response was assessed by neutrophil infiltration, determined by histology and myeloperoxidase (MPO) activity. Interleukin (IL)-1 beta, prostaglandins (PG)E(2) and (PG)D(2) concentrations in colonic tissue, histological and histochemical analysis of the lesions were also measured. Dosmalfate (400-800 mg/kg body weight, p.o.) ameliorated severe colitis reduced the degree of inflammation through reduction of neutrophil infiltration and IL-1 beta levels. (PG)E(2) and (PG)D(2) synthesis were significantly reduced in colitis control group and treatment with dosmalfate abolished the decrease in PG synthesis in colon mucosa. We conclude that dosmalfate is protective in acute DSS-induced colitis. The beneficial effects seem to be related to a decrease of neutrophil infiltration, absence of up-regulation of IL-1 beta and increase of PG production in colon mucosa.

Topics: Administration, Oral; Animals; Colitis, Ulcerative; Colon, Descending; Colon, Transverse; Dextran Sulfate; Dinoprostone; Diosmin; Disease Models, Animal; Drinking; Flavonoids; Interleukin-1; Intestinal Mucosa; Male; Mice; Mice, Inbred BALB C; Neutrophil Infiltration; Peroxidase; Prostaglandin D2; Time Factors; Water

The effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on experimental allergic conjunctivitis, induced by ocular challenge with antigen in actively sensitized guinea pigs, were investigated. NSAIDs reduced the increase in prostaglandin D2 (PGD2) and E2 (PGE2) in the ocular lavage fluid. The inhibition of NSAIDs to these increases was approximately 90%-95%. NSAIDs also lowered itch-scratch response (ISR) to approximately one-third to one-half of the vehicle-treated group. However, these drugs scarcely affected plasma exudation in the conjunctiva. Ketotifen, an H1 histamine receptor antagonist, inhibited both pathophysiological changes (inhibition: 70%-80%). However, this drug was less efficacious than NSAIDs in reducing PGD2 and PGE2 levels. Moreover, topical administration of histamine induced ISR and plasma exudation; in contrast, PGD2 induced ISR exclusively. These results suggest that a part of antigen-induced ISR may be attributable to PGs. However, PGs may not play a key role in plasma exudation; other mediators such as histamine may be involved.

Topics: Administration, Topical; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antigens; Benzophenones; Benzopyrans; Bromobenzenes; Conjunctivitis, Allergic; Diclofenac; Dinoprostone; Disease Models, Animal; Evans Blue; Exudates and Transudates; Eye; Guinea Pigs; Histamine; Histamine Release; Immunization; Injections, Intraperitoneal; Injections, Subcutaneous; Ketotifen; Male; Ovalbumin; Propionates; Prostaglandin D2; Pruritus; Therapeutic Irrigation

Inhalation of heparin attenuates hyperventilation-induced bronchoconstriction in humans and dogs. The purpose of this study was to determine whether heparin inhibits the late-phase response to hyperventilation, which is characterized by increased peripheral airway resistance (RP), eicosanoid mediator production, neutrophilic/ eosinophilic inflammation, and airway hyperreactivity (AHR) at 5 h after dry air challenge (DAC). Fiberoptic bronchoscopy was used to record RP and airway reactivity (DeltaRP) to aerosol and intravenous histamine before and 5 h after DAC. Bronchoalveolar lavage fluid (BALF) cells and eicosanoid mediators were also measured approximately 5 h after DAC. DAC of vehicle-treated bronchi resulted in late-phase airway obstruction (approximately 120% increase over baseline RP), inflammation, increased BALF concentrations of leukotriene (LT) C(4), LTD(4), and LTE(4) and prostaglandin (PG)D(2), and AHR. Pretreatment with aerosolized heparin attenuated late-phase airway obstruction by approximately 50%, inhibited eosinophil infiltration, reduced BALF concentrations of LTC(4), LTD(4), and LTE(4) and PGD(2), and abolished AHR. We conclude that heparin inhibits hyperventilation-induced late-phase changes in peripheral airway function, and does so in part via the inhibition of eosinophil migration and eicosanoid mediator production and release.

Topics: Administration, Inhalation; Airway Resistance; Animals; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoscopy; Disease Models, Animal; Dogs; Drug Evaluation, Preclinical; Eicosanoids; Eosinophils; Heparin; Humans; Hyperventilation; Inflammation; Leukotriene C4; Leukotriene D4; Leukotriene E4; Male; Neutrophils; Prostaglandin D2; Time Factors

15-deoxy-delta (12,14)prostaglandin J(2) (15d-PGJ(2)) has been identified as a natural ligand of the PPARgamma subtype. PPAR activation in nonadipose tissues seems to inhibit iNOS and COX2 expression. Vasoactive compounds like nitric oxide and prostaglandins are increased in pancreatic tissue from streptozotocin-diabetic rats. We hypothesize that 15d-PGJ(2) may regulate the production of these proinflammatory compounds that lead to beta cell destruction in the diabetic pathology. In this work we evaluated Ca(2+)-dependent (cNOS) and Ca(2+)-independent (iNOS) activity, nitrate/nitrite levels, 15-dPGJ(2) and prostaglandin E(2) (PGE(2)) levels in isolated pancreatic islets, and 15d-PGJ(2) levels in plasma from control and streptozotocin-diabetic rats. Our results show that cNOS is predominant in control, while iNOS isoform is increased in the diabetic islets (P < 0.01). 15d-PGJ(2) 10(-5)M inhibits cNOS and iNOS activity both in control and diabetic islets (P < 0.05). Nitrate/nitrite and PGE(2) levels are higher in diabetic than in control islets (P < 0.05 and P < 0.01, respectively). 15d-PGJ(2) 10(-5)M decreases nitrate/nitrite and PGE(2) levels both in control and in diabetic islets. Bisphenol A diglycidyl ether (BADGE), a recently described PPARgamma antagonist, seems to act as a PPARgamma agonist, diminishing nitrate/nitrite and PGE2 levels in control and diabetic islets. 15d-PGJ(2) production is lower in islets from diabetic animals compared to control (P < 0.05). Our observations suggest that 15d-PGJ(2) is able to diminish the production of vasoactive proinflammatory agents in pancreatic islets. The diminished 15d-PGJ(2) levels in the diabetic islets are probably related to the diminished capacity to limit the inflammatory response due to experimental diabetes in the rat.

Topics: Animals; Diabetes Mellitus, Experimental; Disease Models, Animal; Female; Islets of Langerhans; Nitrates; Nitric Oxide; Nitric Oxide Synthase; Nitrites; Prostaglandin D2; Prostaglandins E; Rats; Rats, Wistar; Receptors, Cytoplasmic and Nuclear; Transcription Factors

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors that are related to retinoid, steroid, and thyroid hormone receptors. The PPAR-gamma receptor subtype seems to play a pivotal role in the regulation of cellular proliferation and inflammation. Recent evidence also suggests that the cyclopentenone prostaglandin (PG) 15-deoxyDelta(12,14)-PGJ(2) (15d-PGJ(2)), which is a metabolite of prostaglandin D(2), functions as an endogenous ligand for PPAR-gamma. We postulated that 15d-PGJ(2) would attenuate inflammation. In the present study, we have investigated the effects of 15d-PGJ(2) of acute and chronic inflammation (carrageenan-induced pleurisy and collagen-induced arthritis, respectively) in animal models. We report for the first time, to our knowledge, that 15d-PGJ(2) (given at 10, 30, or 100 microg/kg i.p. in the pleurisy model or at 30 microg/kg i.p every 48 h in the arthritis model) exerts potent anti-inflammatory effects (e.g., inhibition of pleural exudate formation, mononuclear cell infiltration, delayed development of clinical indicators, and histological injury) in vivo. Furthermore, 15d-PGJ(2) reduced the increase in the staining (immunohistochemistry) for nitrotyrosine and poly (ADP-ribose) polymerase and the expression of inducible nitric-oxide synthase and cyclooxygenase-2 in the lungs of carrageenan-treated mice and in the joints from collagen-treated mice. Thus, 15d-PGJ(2) reduces the development of acute and chronic inflammation. Therefore, the cyclopentenone prostaglandin 15d-PGJ(2) may be useful in the therapy of acute and chronic inflammation.

Topics: Animals; Arthritis, Experimental; Carrageenan; Cyclopentanes; Disease Models, Animal; Immunohistochemistry; Immunologic Factors; Inflammation; Male; Mice; Mice, Inbred BALB C; Pleurisy; Prostaglandin D2

Previously we found that some cyclopentenone prostaglandin derivatives promoted neurite outgrowth from PC12 cells and dorsal root ganglia explants in the presence of nerve growth factor; and so we referred to them as neurite outgrowth-promoting prostaglandins (NEPPs). In this study, NEPPs protected HT22 cells against oxidative glutamate toxicity. NEPP6, one of the most effective promoters of neurite outgrowth in PC12 cells, protected the cells most potently among NEPPs 1--10. Several derivatives, NEPPs 11--19, were newly synthesized based on the chemical structure of NEPP6. NEPP11 had a more potent neuroprotective effect than NEPP6. NEPP11 also prevented the death of cortical neurons induced by various stimuli and reduced ischemic brain damage in mice. Biotinylated compounds of NEPPs were synthesized to investigate their cellular accumulation. NEPP6-biotin protected the cells and emitted potent signals from the cells. In contrast, biotinylated non-neuroprotective derivatives emitted much weaker signals. These results suggest that NEPPs are novel types of neurotrophic compounds characterized by their dual biological activities of promoting neurite outgrowth and preventing neuronal death and that their accumulation in the cells is closely associated with their neuroprotective actions.

Topics: Animals; Biotin; Brain Ischemia; Cell Survival; Cells, Cultured; Cyclopentanes; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Mice; Microinjections; Nerve Growth Factors; Neurites; Neurons; Neuroprotective Agents; Prostaglandin D2; Prostaglandins; Structure-Activity Relationship

Focal ischemia was induced in the fronto-parietal region of rat brain, by injection of Rose Bengal, followed by light activation. Focal ischemia was accompanied by formation of PGD(2) peaking 60-90 min post irradiation and declining thereafter. Increased Cycloxygenase-2 (COX-2) expression was also observed. Control ischemic rats showed distinct morphological alterations with necrosis of neurons, glial cells and blood vessels, surrounded by a halo with pyknotic cells with cytoplasm swelling and vacuolization. Compound SC58236, a selective COX-2 inhibitor, dose-dependently prevented, ischemia-induced eicosanoid formation (area under the curve (AUC) of controls: 3.11 +/- 0.87; AUC of 20 mg/kg SC58236: 0.39 +/- 0.24), and caused significant reduction of damaged area (30.7 and 18.9% at SC58236 20 and 6.6 mg/kg), suggesting that selective inhibitors of COX-2 are neuroprotective.

Topics: Animals; Brain Ischemia; Cerebral Cortex; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; Fluorescent Dyes; Isoenzymes; Male; Microdialysis; Microscopy, Electron; Necrosis; Nerve Degeneration; Neurons; Neuroprotective Agents; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Wistar; Rose Bengal; Sulfonamides

In this study, using rat carrageenin-induced pleurisy, we found that treatment of rats with either indomethacin or NS-398 suppressed the pleurisy at 2 h but significantly exacerbated this reaction at 48 h. Exacerbated inflammation was associated with reduced prostaglandin D(2) levels, decreased heat shock factor 1 (HSF1) activation, reduced hsp72 expression and increased activation of nuclear factor kappaB (NF-kappaB). Replacement of cyclopentenone prostaglandins by treating rats with either prostaglandin J(2) or prostaglandin D(2) reversed the exacerbating effects of cyclooxygenase inhibitors leading to the resolution of the reaction. In conclusion, we demonstrate that cyclopentenone prostaglandins may act as anti-inflammatory mediators by inducing in inflammatory cells HSF1-dependent hsp72 expression and NF-kappaB inhibition, two crucial events for the remission of inflammation.

Topics: Active Transport, Cell Nucleus; Animals; Carrageenan; Cyclooxygenase Inhibitors; Disease Models, Animal; DNA-Binding Proteins; Drug Combinations; Exudates and Transudates; Heat Shock Transcription Factors; Heat-Shock Proteins; HSP72 Heat-Shock Proteins; Humans; Indomethacin; Male; NF-kappa B; NF-kappa B p50 Subunit; Nitrobenzenes; Pleura; Pleurisy; Prostaglandin D2; Prostaglandins; Rats; Rats, Wistar; Sulfonamides; Transcription Factor RelA; Transcription Factors

Despite the utility of cyclooxygenase (COX) inhibition as an antiinflammatory strategy, prostaglandin (PG) products of COX-1 and -2 provide important regulatory functions in some pathophysiological states. Scattered reports suggest that COX inhibition may also promote adverse drug events. Here we demonstrate a protective role for endogenous COX-derived products in a murine model of acetaminophen (APAP)-induced acute liver injury. A single hepatotoxic dose caused the selective induction of COX-2 mRNA and increased PGD2 and PGE2 levels within the livers of COX(+/+) male mice suggesting a role for COX-2 in this model of liver injury. APAP-induced hepatotoxicity and lethality were markedly greater in COX-2(-/-) and (-/+) mice in which normal PG responsiveness is altered. The significantly increased toxicity linked to COX-2 deficiency could be mimicked using the selective COX-2 inhibitory drug, celecoxib, in COX(+/+) mice and was not due to alterations in drug-protein adduct formation, a surrogate for bioactivation and toxicity. Microarray analyses indicated that increased injury associated with COX-2 deficiency coincided, most notably, with a profoundly impaired induction of heat shock proteins in COX-2(-/+) mice suggesting that PGs may act as critical endogenous stress signals following drug insult. These findings suggest that COX-2-derived mediators serve an important hepato-protective function and that COX inhibition may contribute to the risk of drug-induced liver injury, possibly through both nonimmunological and immunological pathways.

Topics: Acetaminophen; Animals; Celecoxib; Chemical and Drug Induced Liver Injury; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; DNA Primers; Gene Expression Profiling; Immunoblotting; Isoenzymes; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oligonucleotide Array Sequence Analysis; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sulfonamides; Survival Rate

Xeroderma pigmentosum group A (XPA) gene-deficient mice cannot repair UV-induced DNA damage and easily develop skin cancers by UV irradiation. Therefore, XPA-deficient mice are a useful model of human XP and represent a promising tool for photobiologic studies of the disorder. Exposure to ultraviolet (UV) B (280-320 nm) radiation greatly enhanced inflammation and immunosuppression in these mice. To investigate the molecular mechanisms of enhanced UV inflammation and immunosuppression, we determined the amount of prostaglandin (PG) E2, an inflammatory mediator and immunomodulator, and analysed the expression of cyclooxygenase (COX) mRNA in the ear skin of XPA-deficient mice after UV irradiation. In XPA-deficient mice, the amount of PGE2 significantly increased at 48 and 72 h after UVB irradiation to the level that was 8- and 16-fold higher than those in wild-type mice, respectively. The expression level of COX-2 mRNA increased in a time-dependent manner, although COX-1 mRNA was constantly expressed. Treatment with indomethacin, a potent inhibitor of PG biosynthesis, inhibited UV-induced ear swelling, abrogated local immunosuppression, and decreased the amount of PGE2 in the ear skin of XPA-deficient mice. These results indicate that the excess DNA photoproducts remaining in XPA-deficient cells after UV radiation may induce COX-2 expression. The induced production of PGE2 may be involved in the enhanced inflammation and immunosuppression caused by UV radiation in XPA-deficient mice and XP patients.

Topics: Animals; Cyclooxygenase 1; Cyclooxygenase 2; Cytosol; Dinoprost; Dinoprostone; Disease Models, Animal; Ear; Edema; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Immune Tolerance; Indomethacin; Isoenzymes; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Phospholipases A; Photosensitivity Disorders; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; RNA, Messenger; Ultraviolet Rays; Xeroderma Pigmentosum

The ability of nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors to exacerbate inflammatory bowel disease suggests that prostaglandins are important anti-inflammatory mediators in this context. Prostaglandin D(2) has been suggested to exert anti-inflammatory effects. We investigated the possibility that prostaglandin D(2) derived from cyclooxygenase-2 plays an important role in downregulating colonic inflammation in rats. Colitis was induced by intracolonic administration of trinitrobenzene sulfonic acid. At various times thereafter (from 1 h to 7 days), colonic prostaglandin synthesis and myeloperoxidase activity (index of granulocyte infiltration) were measured. Prostaglandin D(2) synthesis was elevated >4-fold above controls within 1-3 h of induction of colitis, preceding significant granulocyte infiltration. Treatment with a selective cyclooxygenase-2 inhibitor abolished the increase in prostaglandin D(2) synthesis and caused a doubling of granulocyte infiltration. Colonic granulocyte infiltration was significantly reduced by administration of prostaglandin D(2) or a DP receptor agonist (BW-245C). These results demonstrate that induction of colitis results in a rapid increase in prostaglandin D(2) synthesis via cyclooxygenase-2. Prostaglandin D(2) downregulates granulocyte infiltration into the colonic mucosa, probably through the DP receptor.

Topics: Animals; Blotting, Western; Celecoxib; Colitis; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Hydantoins; Indomethacin; Intramolecular Oxidoreductases; Isoenzymes; Lipocalins; Male; Necrosis; Neutrophils; Peroxidase; Peroxisomes; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Wistar; Receptors, Cytoplasmic and Nuclear; Receptors, Immunologic; Receptors, Prostaglandin; RNA, Messenger; Sulfonamides; Transcription Factors

Pilocarpine (PILO) administered to rats acutely induces status epilepticus (acute period), which is followed by a transient seizure-free period (silent period), and finally by a chronic phase of spontaneous recurrent seizures (chronic period, SRS) that lasts for the rest of animal's life. Hippocampal neurochemical changes following PILO administration include alteration in monoamines and amino acids content during all phases of this epilepsy model. The present work was delineated to study the content of prostaglandins (PG) levels in hippocampus during the three phases of this model. The levels of PG E2, PG F2 alpha and PG D2 were measured by radioimmunoassay 1 h after PILO, 5 h after PILO, during the silent period, and interictally into the chronic period. The results show, in hippocampus of rats, increase of PG F2 alpha and PG D2 during status epilepticus, increase of PG D2 during the silent period and increase of PG E2 and PG D2 during the chronic phase, when compared with control group. These changes match previously reported alteration in monoamines and amino acid levels, showing that altered neurotransmission is accompanied by changes in second messengers and enzyme activity related to PG production during all phases of the epilepsy model.

Topics: Animals; Dinoprost; Dinoprostone; Disease Models, Animal; Epilepsy; Hippocampus; Male; Muscarinic Agonists; Pilocarpine; Prostaglandin D2; Rats; Rats, Wistar; Recurrence; Status Epilepticus

Western red cedar asthma is the most common form of occupational asthma in the Pacific Northwest. Plicatic acid (PA) is the chemical component of Western red cedar that causes asthma. The role of immunologic processes involved in the PA-induced asthmatic reaction has not been established. To characterize the mechanisms of PA-induced asthmatic reaction, guinea pigs were sensitized to PA through biweekly injection of PA-ovalbumin conjugate with aluminum hydroxide as an adjuvant for a period of 6 months. Specific IgG1 antibodies to PA were detected in the blood 3 months after sensitization of animals. The level of specific IgG1 antibodies to ovalbumin after 6 months was about two times the level of specific IgG1 to PA. At 6 months, tracheal tissue from PA-ovalbumin-sensitized guinea pigs contracted after exposure to either PA or ovalbumin in vitro. The degree of contraction induced by PA was two to three times less than the contraction induced by ovalbumin. PA caused histamine, prostaglandin D2, and leukotriene D4 release from both lung mast cells and blood basophils. The amount of histamine and eicosanoids released by PA was also two to three times less than the amount of mediators released by ovalbumin. When the trachea of normal guinea pigs was passively sensitized with serum from PA-ovalbumin-sensitized guinea pigs, it contracted in response to PA or ovalbumin in an organ bath. When the serum of PA-ovalbumin-sensitized guinea pigs was depleted of immunoglobulins and then used for passive sensitization of normal trachea, no contraction was observed when challenged with PA, suggesting that IgG1 antibodies mediate the tracheal reaction to PA.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Allergens; Animals; Asthma; Disease Models, Animal; Guinea Pigs; Immunization; Immunoglobulin G; In Vitro Techniques; Leukotriene D4; Lignans; Lung; Male; Muscle Contraction; Muscle, Smooth; Naphthols; Prostaglandin D2; Time Factors; Trachea; Trees

To determine if late asthmatic response (LAR) is associated with hyperresponsiveness of airway smooth muscle itself, we performed antigen challenge in dogs treated with Metopirone. We studied the contractile response to acetylcholine (ACh) in isolated bronchial and bronchiolar segments 8 h after either saline inhalation (the control group) or antigen challenge in dogs demonstrating immediate asthmatic response (IAR) alone and in dogs demonstrating both IAR and LAR. Airway responses to Ascaris suum antigen were assessed by changes in respiratory resistance measured with the forced oscillation technique at 3 Hz. Concentration-response curves of bronchial preparations to ACh did not differ significantly among three groups consisting of the control, IAR and LAR. However, the contractile response of bronchiolar preparations to ACh was significantly greater in the LAR group when compared to the control and IAR groups at the concentrations of ACh ranging from 10(-6) to 3 x 10(-4) M (p < 0.01). SQ 29548, a receptor antagonist of thromboxane A2 and prostaglandin D2 (PGD2), inhibited LAR-induced hyperresponsiveness to ACh in a concentration-dependent fashion. The bronchiolar preparations obtained from dogs showing LAR contained a significantly higher amount of PGD2 than those obtained from dogs showing IAR alone (p < 0.01, n = 6). These results suggest that LAR is associated with hyperresponsiveness of peripheral airway smooth muscle to ACh, and this augmented response to ACh mediates via PGD2 released during LAR.

Topics: Acetylcholine; Airway Resistance; Animals; Asthma; Bronchial Hyperreactivity; Disease Models, Animal; Dogs; Hydrocortisone; Muscle Contraction; Muscle, Smooth; Prostaglandin D2

In the present study we have investigated the effects of high-dose methylprednisolone (MP) treatment on the 'ex vivo' release of four major eicosanoids in an experimental model of subarachnoid haemorrhage (SAH) with the aim of verifying: (a) the efficacy in reducing arachidonic acid metabolism enhancement; (b) whether high-dose methylprednisolone is effective on both the cyclooxygenase and lipoxygenase pathways; and (c) discussing the possible role of high-dose MP treatment in brain protection after SAH. Levels of prostaglandin D2 and E2, prostacyclin and also leukotriene C4 were determined by the radioimmunoassay technique after 1 h incubation of cerebral cortex samples of rats which had been subjected to experimental SAH procedure (injection of 0.3 ml of autologous arterial blood). The release of prostaglandin D2 at 48 h after SAH is significantly higher when compared to that of sham-operated animals (P less than 0.01); prostaglandin E2 release is significantly enhanced at 6 h after the SAH procedure (P less than 0.01); release of the lipoxygenase metabolite is significantly enhanced at 1, 6 and 48 h after SAH induction; MP significantly decreases the release of all eicosanoids, and values in treated animals do not differ from those of sham-operated animals. The results of the present study suggest that the global inhibitory effect of high-dose MP treatment on the 'ex vivo' release of eicosanoids after experimental SAH could be considered to be one of the neurochemical correlates for the reduced incidence and severity of arterial inflammatory response, which results in chronic vasospasm and supports the clinical evidence of MP efficacy in preventing or reducing the incidence of arterial vasospasm after aneurysmal rupture.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Pressure; Cerebral Cortex; Dinoprostone; Disease Models, Animal; Eicosanoids; In Vitro Techniques; Kinetics; Male; Prostaglandin D2; Rats; Rats, Inbred Strains; Reference Values; SRS-A; Subarachnoid Hemorrhage

After antenatal induction of diaphragmatic hernias in fetal lambs, prostaglandins D2, E1, and I2 were compared to tolazoline, or isoprenaline, for the treatment of pulmonary hypertension. When rendered hypoxic, these, and normal lambs, showed an increase in pulmonary artery pressure, a decrease in systemic pressure, and a decrease in pulmonary blood flow. All of the drugs altered that response, but to different degrees. None of the drugs tested was consistently successful in reversing the adverse affects of hypoxia, but prostaglandin D2 came closest to the ideal vasodilator, decreasing the pulmonary artery pressure in all seven hypoxic lambs having a diaphragmatic hernia. There was a concomitant increase in pulmonary blood flow in six; in the remaining lamb the decrease in blood flow induced by the hypoxia was arrested. At the same time, there was an increase in systemic artery pressure in three, the decrease was arrested in two, but the decrease continued in the other two. Isoprenaline was a more effective drug than tolazoline, producing an increase in pulmonary blood flow in five of the seven lambs, with minor decreases in systemic pressure in five. Tolazoline improved blood flow in three of six lambs (not all lambs survived the full study), with a marked decrease in systemic pressure in four of them. Prostaglandin D2 seems to be a useful drug for the treatment of patients having diaphragmatic hernias and pulmonary hypertension, and warrants further study. Isoprenaline was the most effective of the readily available drugs tested in this animal model.

Topics: Animals; Blood Flow Velocity; Blood Pressure; Disease Models, Animal; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Humans; Hypertension, Pulmonary; Isoproterenol; Prostaglandin D2; Pulmonary Artery; Sheep; Tolazoline