transforming-growth-factor-beta has been researched along with Diabetic-Retinopathy* in 63 studies
18 review(s) available for transforming-growth-factor-beta and Diabetic-Retinopathy
Article | Year |
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Brain-derived neurotrophic factor in diabetes mellitus: A systematic review and meta-analysis.
Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor expressed in several tissues, including the brain, gut, and pancreas. Activation of the BDNF/TrkB/CREB reduces hepatic gluconeogenesis, induces hepatic insulin signal transduction, and protects against pancreatic beta-cell loss in diabetes mellitus (DM). Several studies have investigated the possible association between BDNF and DM and its complications, but the results have been conflicting.. In the present study, we aimed at systematically reviewing the literature on the serum and plasma levels of BDNF in DM and its subgroups such as T2DM, DM patients with depression, and patients with retinopathy.. A comprehensive search was conducted in PubMed, Scopus, and Web of Science. We identified 28 eligible studies and calculated the standardized mean difference (SMD) of outcomes as an effect measure.. The meta-analysis included 2734 patients with DM and 6004 controls. Serum BDNF levels were significantly lower in patients with DM vs. controls (SMD = -1.00, P<0.001). Plasma BDNF levels were not different in patients with DM compared with controls. When conducting subgroup analysis, serum BDNF levels were lower among patients with T2DM (SMD = -1.26, P<0.001), DM and depression (SMD = -1.69, P<0.001), and patients with diabetic retinopathy (DR) vs. controls (SMD = -1.03, P = 0.01).. Serum BDNF levels were lower in patients with DM, T2DM, DM with depression, and DM and DR than the controls. Our findings are in line with the hypothesis that decreased BDNF levels might impair glucose metabolism and contribute to the pathogenesis of DM and its complications. Topics: Brain-Derived Neurotrophic Factor; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Humans; Transforming Growth Factor beta | 2023 |
TGF-β Superfamily Signaling in the Eye: Implications for Ocular Pathologies.
The TGF-β signaling pathway plays a crucial role in several key aspects of development and tissue homeostasis. TGF-β ligands and their mediators have been shown to be important regulators of ocular physiology and their dysregulation has been described in several eye pathologies. TGF-β signaling participates in regulating several key developmental processes in the eye, including angiogenesis and neurogenesis. Inadequate TGF-β signaling has been associated with defective angiogenesis, vascular barrier function, unfavorable inflammatory responses, and tissue fibrosis. In addition, experimental models of corneal neovascularization, diabetic retinopathy, proliferative vitreoretinopathy, glaucoma, or corneal injury suggest that aberrant TGF-β signaling may contribute to the pathological features of these conditions, showing the potential of modulating TGF-β signaling to treat eye diseases. This review highlights the key roles of TGF-β family members in ocular physiology and in eye diseases, and reviews approaches targeting the TGF-β signaling as potential treatment options. Topics: Diabetic Retinopathy; Eye; Eye Diseases; Homeostasis; Humans; Neovascularization, Pathologic; Signal Transduction; Transforming Growth Factor beta | 2022 |
Impact of dexamethasone and tocilizumab on hematological parameters in COVID-19 patients with chronic disease.
The most effective way to control severity and mortality rate of the novel coronavirus disease (COVID-19) is through sensitive diagnostic approaches and an appropriate treatment protocol. We aimed to identify the effect of adding corticosteroid and Tocilizumab to a standard treatment protocol in treating COVID-19 patients with chronic disease through hematological and lab biomarkers.. This study was performed retrospectively on 68 COVID-19 patients with chronic disease who were treated by different therapeutic protocols. The patients were categorized into four groups: control group represented the patients' lab results at admission before treatment protocols were applied; group 1 included patients treated with anticoagulants, Hydroxychloroquine, and antibiotics; group 2 comprised patients treated with Dexamethasone; and group 3 included patients treated with Dexamethasone and Tocilizumab.. The study paves the way into the effectiveness of combining Dexamethasone with Tocilizumab in treatment COVID-19 patients with chronic diseases.. La forma más eficaz de controlar la gravedad y la tasa de mortalidad de la enfermedad del nuevo coronavirus (COVID-19) es mediante enfoques de diagnóstico sensibles y un protocolo de tratamiento adecuado. Nuestro objetivo fue identificar el efecto de agregar corticosteroides y tocilizumab a un protocolo de tratamiento estándar en el tratamiento de pacientes con COVID-19 con enfermedad crónica a través de biomarcadores hematológicos y de laboratorio.. Este estudio se realizó de forma retrospectiva en 68 pacientes COVID-19 con enfermedad crónica que fueron tratados por diferentes protocolos terapéuticos. Los pacientes se clasificaron en cuatro grupos: el grupo de control representaba los resultados de laboratorio de los pacientes en el momento de la admisión antes de que se aplicaran los protocolos de tratamiento; el grupo 1 incluyó a pacientes tratados con anticoagulantes, hidroxicloroquina y antibióticos; el grupo 2 estaba compuesto por pacientes tratados con dexametasona; y el grupo 3 incluyó a pacientes tratados con dexametasona y tocilizumab.. El estudio allana el camino hacia la eficacia de la combinación de dexametasona con tocilizumab en el tratamiento de pacientes con COVID-19 con enfermedades crónicas.. The Child-Mother Index constitutes a potential useful risk factor indicator for statistical analyses on data after birth. The value of the Child-Mother Index based on the estimated fetal weight before birth deserves evaluation.. Six ceria supports synthesized by various synthesis methodologies were used to deposit cobalt oxide. The catalysts were thoroughly characterized, and their catalytic activity for complete methane oxidation was studied. The supports synthesized by direct calcination and precipitation with ammonia exhibited the best textural and structural properties as well as the highest degree of oxidation. The remaining supports presented poorer textural properties to be employed as catalytic supports. The cobalt deposited over the first two supports presented a good dispersion at the external surface, which induced a significant redox effect that increased the number of Co. Some studies show that children with obesity are more likely to receive a diagnosis of depression, anxiety, or attention-deficit hyperactivity disorder (ADHD). But this does not necessarily mean obesity causes these conditions. Depression, anxiety, or ADHD could cause obesity. A child's environment, including family income or their parents' mental health, could also affect a child's weight and mental health. Understanding the nature of these relationships could help scientists develop better interventions for both obesity and mental health conditions. Genetic studies may help scientists better understand the role of the environment in these conditions, but it's important to consider both the child's and their parents’ genetics in these analyses. This is because parents and children share not only genes, but also environmental conditions. For example, families that carry genetic variants associated with higher body weight might also have lower incomes, if parents have been affected by biases against heavier people in society and the workplace. Children in these families could have worse mental health because of effects of their parent’s weight, rather than their own weight. Looking at both child and adult genetics can help disentangle these processes. Hughes et al. show that a child's own body mass index, a ratio of weight and height, is not strongly associated with the child’s mental health symptoms. They analysed genetic, weight, and health survey data from about 41,000 8-year-old children and their parents. The results suggest that a child's own BMI does not have a large effect on their anxiety symptoms. There was also no clear evidence that a child's BMI affected their symptoms of depression or ADHD. These results contradict previous studies, which did not account for parental genetics. Hughes et al. suggest that, at least for eight-year-olds, factors linked with adult weight and which differ between families may be more critical to a child's mental health than a child’s own weight. For older children and adolescents, this may not be the case, and the individual’s own weight may be more important. As a result, policies designed to reduce obesity in mid-childhood are unlikely to greatly improve the mental health of children. On the other hand, policies targeting the environmental or societal factors contributing to higher body weights, bias against people with higher weights, and poor child mental health directly may be more beneficial.. The development of an efficient photocatalyst for C2 product formation from CO. Оценка антиастенического эффекта последовательной терапии левокарнитином (ЛК) и ацетилкарнитином (АЛК) пациентов с артериальной гипертензией и/или ишемической болезнью сердца (ИБС) с астеническим синдромом (АС).. В открытое сравнительное исследование были включены 120 пациентов в возрасте 54—67 лет с артериальной гипертензией и/или ИБС с АС. Пациенты 1-й группы (. У больных 1-й группы отмечено статистически значимое уменьшение различных проявлений АС. Отличия носили достоверный характер по сравнению как с исходным уровнем, так и со 2-й группой. Установлено эндотелийпротективное действие ЛК и АЛК.. Полученные результаты свидетельствуют, что у таких коморбидных пациентов использование ЛК и АЛК уменьшает выраженность проявлений АС, а установленные эндотелиотропные свойства препаратов позволяют рекомендовать их в составе комплексной персонифицированной терапии пациентов с сердечно-сосудистыми заболеваниями.. Naproxen sodium 440 mg/diphenhydramine 50 mg combination demonstrated improvement in sleep maintenance (WASO) vs. naproxen sodium 550 mg and higher efficiency in average daily pain reduction compared with the comparison groups. The treatment was well tolerated There were no serious or unexpected adverse events reported in the study.. Сравнительный анализ эффективности и безопасности новой комбинации напроксена натрия и дифенгидрамина у пациентов с неспецифическим болевым синдромом в пояснично-крестцовом отделе спины (M54.5 «Боль внизу спины») и нарушением сна (G47.0 «Нарушения засыпания и поддержания сна [бессонница]»).. Проведено проспективное многоцентровое рандомизированное открытое сравнительное в параллельных группах клиническое исследование. Пациенты были рандомизированы в 3 группы. Больные 1-й группы получали напроксен натрия (440 мг) и дифенгидрамин (50 мг), 2-й — напроксен натрия (550 мг), 3-й — парацетамол (1000 мг) и дифенгидрамин (50 мг). Исследуемые препараты пациенты принимали однократно перед сном в течение 3 дней. Все пациенты также принимали 275 мг (1 таблетка) напроксена натрия в качестве препарата фоновой терапии. Первичным критерием эффективности было общее время бодрствования после наступления сна (WASO), измеряемое методом актиграфии. Также использовались критерии оценки продолжительности и качества сна и выраженности боли.. Анализ эффективности проведен для ITT популяции (. Применение комбинации напроксена натрия (440 мг) и дифенгидрамина (50 мг) характеризовалось более выраженным поддержанием сна по сравнению с напроксеном натрия 550 мг и более высокой эффективностью в отношении снижения интенсивности боли по сравнению со 2-й и 3-й группами. Отмечена хорошая переносимость препарата, серьезных нежелательных явлений зарегистрировано не было. Topics: Acetaminophen; Acetylcarnitine; Acetylcholinesterase; Acids; Acinetobacter baumannii; Acinetobacter Infections; Adaptation, Psychological; Adolescent; Adsorption; Adult; Aged; Alcohol Drinking; Alzheimer Disease; Amikacin; Ammonia; Anaerobiosis; Animals; Anorexia; Anti-Bacterial Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Anxiety; Aptamers, Nucleotide; Asthenia; Attention Deficit Disorder with Hyperactivity; Bacterial Proteins; Beryllium; beta-Lactamases; Biofuels; Biomass; Biosensing Techniques; Bismuth; Blister; Body Mass Index; Body Surface Area; Boronic Acids; Brain; Breast Neoplasms; Butyrylcholinesterase; Cannabis; Carbapenems; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Carboxylic Acids; Carcinoma, Hepatocellular; Cardiovascular Diseases; Carnitine; Case-Control Studies; Catalysis; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Child; China; Cholinesterase Inhibitors; Clarithromycin; Clostridioides; Clostridioides difficile; Clostridium Infections; Cohort Studies; Colistin; Colitis; Colon; Coloring Agents; Coronary Artery Bypass; Creatinine; Crystalloid Solutions; Cytokines; Depression; Dextran Sulfate; Dextrans; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Diarrhea; Dietary Supplements; Diphenhydramine; Disease Models, Animal; Disease Outbreaks; Double-Blind Method; Doxorubicin; Drosophila; Drug Tapering; Dysbiosis; Electrons; Escherichia coli; Extracellular Vesicles; Fatigue; Female; Fermentation; gamma-Cyclodextrins; Gastrointestinal Microbiome; Glucose; Graft Survival; Graft vs Host Disease; Head and Neck Neoplasms; Heart Arrest, Induced; Hematopoietic Stem Cell Transplantation; High-Intensity Interval Training; Hippocampus; Humans; Hydrogen-Ion Concentration; Hypertension; Incidence; Interferon-gamma; Italy; Kinetics; Klebsiella Infections; Klebsiella pneumoniae; Lab-On-A-Chip Devices; Lactoferrin; Larva; Length of Stay; Lignin; Liver; Liver Neoplasms; Liver Transplantation; Living Donors; Low Back Pain; Lung; Lung Volume Measurements; Macrophages; Male; Melphalan; Men; Mendelian Randomization Analysis; Meropenem; Methane; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Mitochondrial Proteins; Molecular Docking Simulation; Molecular Structure; Mothers; Motivation; Mycoplasma; Mycoplasma hominis; Mycoplasma Infections; NAD; Nanocomposites; Nanoparticles; Nanotubes, Carbon; Naproxen; Neovascularization, Pathologic; Neurons; Nitrates; Nucleolin; Opuntia; Paratyphoid Fever; Phenotype; Phosphatidylinositol 3-Kinases; Phytochemicals; Plant Extracts; Pregnancy; Prevalence; Prospective Studies; Proto-Oncogene Proteins c-akt; Pulmonary Disease, Chronic Obstructive; Rats; Rats, Wistar; Resveratrol; Retrospective Studies; Rifampin; Risk Factors; RNA, Messenger; Selenium; Sleep; Social Behavior; Soil; Soil Pollutants; Squamous Cell Carcinoma of Head and Neck; Staphylococcus aureus; Structure-Activity Relationship; Suicidal Ideation; Suicide; Superoxide Dismutase-1; Surveys and Questionnaires; Swimming; Syndrome; Tannins; Temperature; Transforming Growth Factor beta; Transplantation Conditioning; Treatment Outcome; Triple Negative Breast Neoplasms; Troponin T; Tumor Microenvironment; United Kingdom; Ureaplasma; Ureaplasma urealyticum; Urinary Tract Infections; Viscum; Waste Disposal Facilities; Wastewater; Water; Water Pollutants, Chemical; Wolfiporia; Young Adult | 2022 |
Dual Roles of the AMP-Activated Protein Kinase Pathway in Angiogenesis.
Angiogenesis plays important roles in development, stress response, wound healing, tumorigenesis and cancer progression, diabetic retinopathy, and age-related macular degeneration. It is a complex event engaging many signaling pathways including vascular endothelial growth factor (VEGF), Notch, transforming growth factor-beta/bone morphogenetic proteins (TGF-β/BMPs), and other cytokines and growth factors. Almost all of them eventually funnel to two crucial molecules, VEGF and hypoxia-inducing factor-1 alpha (HIF-1α) whose expressions could change under both physiological and pathological conditions. Hypoxic conditions stabilize HIF-1α, while it is upregulated by many oncogenic factors under normaxia. HIF-1α is a critical transcription activator for VEGF. Recent studies have shown that intracellular metabolic state participates in regulation of sprouting angiogenesis, which may involve AMP-activated protein kinase (AMPK). Indeed, AMPK has been shown to exert both positive and negative effects on angiogenesis. On the one hand, activation of AMPK mediates stress responses to facilitate autophagy which stabilizes HIF-1α, leading to increased expression of VEGF. On the other hand, AMPK could attenuate angiogenesis induced by tumor-promoting and pro-metastatic factors, such as the phosphoinositide 3-kinase /protein kinase B (Akt)/mammalian target of rapamycin (PI3K/Akt/mTOR), hepatic growth factor (HGF), and TGF-β/BMP signaling pathways. Thus, this review will summarize research progresses on these two opposite effects and discuss the mechanisms behind the discrepant findings. Topics: AMP-Activated Protein Kinases; Animals; Carcinogenesis; Diabetic Retinopathy; Eye; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Macular Degeneration; Mice; Neoplasms; Neovascularization, Pathologic; Neovascularization, Physiologic; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A | 2019 |
Emerging Roles of Transforming Growth Factor β Signaling in Diabetic Retinopathy.
Diabetic retinopathy (DR) is a serious complication of diabetes mellitus affecting about one third of diabetic adults. Despite its prevalence, treatment options are limited and often implemented only in the later stages of the disease. To date, the pathogenesis of DR has been extensively characterized in the context of elevated glucose, insulin, and VEGF signaling, although a growing number of other growth factors and molecules, including transforming growth factor β (TGF-β) are being recognized as important contributors and/or therapeutic targets. Here, we review the complex roles of TGF-β signaling in DR pathogenesis and progression. J. Cell. Physiol. 232: 486-489, 2017. © 2016 Wiley Periodicals, Inc. Topics: Animals; Diabetic Retinopathy; Disease Progression; Humans; Models, Biological; Signal Transduction; Transforming Growth Factor beta | 2017 |
Biomarkers in diabetic retinopathy and the therapeutic implications.
The main problem both in type 1 (T1DM) and type 2 (T2DM) diabetes is the development of chronic vascular complications encompassing micro- as well as macrocirculation. Chronic complications lower the quality of life, lead to disability, and are the cause of premature death in DM patients. One of the chronic vascular complications is a diabetic retinopathy (DR) which leads to a complete loss of sight in DM patients. Recent trials show that the primary cause of diabetic retinopathy is retinal neovascularization caused by disequilibrium between pro- and antiangiogenic factors. Gaining knowledge of the mechanisms of action of factors influencing retinal neovascularization as well as the search for new, effective treatment methods, especially in advanced stages of DR, puts special importance on research concentrating on the implementation of biological drugs in DR therapy. At present, it is antivascular endothelial growth factor and antitumor necrosis factor that gain particular significance. Topics: Adalimumab; Angiogenesis Inhibitors; Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antibodies, Monoclonal, Murine-Derived; Aptamers, Nucleotide; Bevacizumab; Biomarkers; Diabetic Retinopathy; Etanercept; Eye Proteins; Humans; Immunoglobulin G; Infliximab; Interleukin-12; Mice; Neovascularization, Pathologic; Nerve Growth Factors; Quality of Life; Ranibizumab; Receptors, Tumor Necrosis Factor; Rituximab; Serpins; Somatomedins; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A | 2013 |
Chymase as an important target for preventing complications of metabolic syndrome.
Chymase plays a crucial role in angiotensin II formation in various tissues. Angiotensin II induces gene expressions of transforming growth factor (TGF)-β and matrix metalloproteinase (MMP)-9, and chymase also converts precursors of TGF-β and MMP-9 to their active forms. All of angiotensin II, TGF-β and MMP-9 are considered to be closely involved in the development and progression of metabolic syndrome and its complications. In a diabetic animal model, chymase induced pancreatic disorganization via attack of oxidative stress induced by augmentation of chymase-forming angiotensin II. In atherosclerotic lesions in patients, accumulation of chymase-positive cells was observed, and chymase inhibition prevented the development of atherosclerosis in an animal model. In Apo E-deficient mice, chymase inhibition prevents the development of angiotensin II-induced abdominal aneurysmal aorta (AAA). In this model, the AAA development on an increase in MMP-9 activities induced by angiotensin II, but the inhibition of MMP-9 activation by chymase inhibitor resulted in attenuation of the AAA development. Cardiac dysfunction after myocardial infarction was also attenuated by chymase inhibition. Steatosis and fiblosis in liver were strongly prevented by chymase inhibition in an animal model with nonalcoholic steatohepatitis which is involved in metabolic syndrome. Therefore, chymase inhibition may be useful for attenuating MMP-9 and TGF-β levels, in addition to reducing angiotensin II formation, and this function may provide powerful preventions of organ damages. In this review, we propose the significance of chymase as a target to prevent complications of metabolic syndrome. Topics: Angiotensin II; Animals; Atherosclerosis; Chymases; Diabetes Complications; Diabetic Retinopathy; Fatty Liver; Humans; Hypertension; Matrix Metalloproteinase 9; Metabolic Syndrome; Mice; Transforming Growth Factor beta | 2010 |
Fibrosis in diabetes complications: pathogenic mechanisms and circulating and urinary markers.
Diabetes mellitus is characterized by a lack of insulin causing elevated blood glucose, often with associated insulin resistance. Over time, especially in genetically susceptible individuals, such chronic hyperglycemia can cause tissue injury. One pathological response to tissue injury is the development of fibrosis, which involves predominant extracellular matrix (ECM) accumulation. The main factors that regulate ECM in diabetes are thought to be pro-sclerotic cytokines and protease/anti-protease systems. This review will examine the key markers and regulators of tissue fibrosis in diabetes and whether their levels in biological fluids may have clinical utility. Topics: Animals; Basement Membrane; Biomarkers; Cardiomyopathies; Connective Tissue Growth Factor; Diabetes Complications; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Endothelium, Vascular; Extracellular Matrix; Fatty Liver; Fibrosis; Glycation End Products, Advanced; Heart Diseases; Heart Failure; Humans; Hyperglycemia; Immediate-Early Proteins; Insulin Resistance; Intercellular Signaling Peptides and Proteins; Liver Cirrhosis; Metalloproteases; Peptide Fragments; Procollagen; Renin-Angiotensin System; Transforming Growth Factor beta; Tunica Intima; Up-Regulation | 2008 |
[The role of transforming growth factor-beta in the pathogenesis of diabetic retinopathy].
Diabetic retinopathy is a micro-angiopathy affecting predominantly small vessels of the retina. Proliferative diabetic retinopathy is characterised by preretinal neovascularisation and fibrosis leading to vitreous heamorrhage and tractional retinal detachment. Chronic hyperglicemia may cause growth factor alterations that are likely to participate in tissue remodeling typical for this late complication. Numerous angiogenic and mitogenic factors have been demonstrated to be present in the eye, including transforming growth factor-beta (TGF-beta), insulin-like growth factors, fibroblast growth factor, tumor necrosis factor and vascular endothelial growth factor. TGF-beta is involved in the control of endothelial cell proliferation, adhesion and deposition of extracellular matrix, thus TGF-beta may play a role in the control of endothelial cell proliferation seen in the disease. The role of TGF-beta in diabetic retinopathy enables better understanding, and thus in the future better intensive antidiabetic therapy in aspect of ophthalmic complications. Topics: Chronic Disease; Diabetic Retinopathy; Humans; Hyperglycemia; Receptors, Transforming Growth Factor beta; Retina; Transforming Growth Factor beta | 2006 |
Down-regulation of angiogenic inhibitors: a potential pathogenic mechanism for diabetic complications.
Diabetic retinopathy (DR) and diabetic nephropathy (DN) are the most common microvascular complications of diabetes. DR is a leading cause of blindness, and DN is a major cause of end-stage renal diseases. Diabetic macular edema (DME) resulting from increased vascular permeability in the retina and retinal neovascularization (NV) represent two major pathological changes in DR and are the primary causes of vision loss in diabetic patients. Previous studies have shown that angiogenic factors such as vascular endothelial growth factor (VEGF) play a key role in the development of DME and retinal NV. Studies in recent years have demonstrated that a number of endogenous angiogenic inhibitors are present in the normal retina and counter act the effect of VEGF in the regulation of angiogenesis and vascular permeability. Decreased levels of angiogenic inhibitors in the vitreous and retina have been found in diabetic patients and diabetic animal models. The decreased levels of angiogenic inhibitors shift the balance between angiogenic factors and angiogenic inhibitors and consequently, lead to the development of DME and retinal NV. Recently, we have found that these angiogenic inhibitors are expressed at high levels in the normal kidney and are down-regulated in diabetes. Moreover, these inhibitors inhibit the activity of VEGF and TGF-beta, two major pathogenic factors of DN. Therefore, decreased levels of these angiogenic inhibitors in diabetes may be associated with pathologies of DN. This review will summarize recent progress in these fields and therapeutic approaches to use angiogenic inhibitors for the treatment of diabetic complications. Topics: Angiogenesis Inhibitors; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Down-Regulation; Growth Substances; Humans; Incidence; Models, Biological; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A | 2005 |
New concepts in pathogenesis and treatment of diabetic retinopathy.
Retinal neovascularization is a major feature of proliferative diabetic retinopathy, which represents a major public health problem, being responsible for more irreversible blindness in persons of middle and older age than any other pathology. The societal burden of ocular neovascularization has prompted extensive research into its mechanisms. The aim of this review will be to briefly summarize the current knowledge regarding the clinical and laboratory findings of diabetic retinopathy. From an investigational view, studies of ocular neovascularization provide important informations, often permitting real-time, serial observations of neovascularization in vivo. This allows investigators to analyse the relevance of specific pathogenic concepts regarding the mechanisms of angiogenesis in vivo. This review will additionally describe current concepts regarding the pathogenesis and treatment of diabetic retinopathy. Topics: Animals; Diabetic Retinopathy; Endothelial Growth Factors; Humans; Insulin-Like Growth Factor I; Lymphokines; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors | 2001 |
Role of growth factors in the development of diabetic complications.
The structural changes characterising diabetic microangiopathy, which may be referred to as 'abnormal growth' and 'impaired regeneration', strongly suggest a role for a number of aberrantly expressed growth factors, possibly acting in combination, in the development of these complications. This initial speculation has been supported by the detection of increased concentrations of several growth factors in the target tissues of diabetic long-term complications, and by enhanced expression of these growth factors consequent to the activation of the biochemical pathways linking hyperglycaemia to microvascular changes: the polyol pathway; non-enzymatic glycation of proteins; vasoactive hormones; oxidative stress, and hyperglycaemic pseudohypoxia. As to nephropathy, insulin-like growth factor I (IGF-I) seems to be implicated in the earlier stages of the disease, while transforming growth factor beta (TGF beta) is involved both in the early and later stages, being responsible, at least in part, for extracellular matrix (ECM) accumulation. Vascular endothelial growth factor (VEGF) plays a pivotal role both in non-proliferative and proliferative retinopathy. Finally, deficiency of several neurotrophic factors, namely nerve growth factor (NGF) and IGF-I has been related to the degeneration or impaired regeneration occurring in diabetic neuropathy. Knowledge of the involvement of growth factors in diabetic microangiopathy opens the way to new therapeutic interventions aimed at blocking the deleterious actions of several growth factors. Topics: Diabetes Mellitus, Type 1; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Endothelial Growth Factors; Growth Substances; Humans; Insulin-Like Growth Factor I; Lymphokines; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors | 2000 |
[Eye and pathologic angiogenesis].
Topics: Angiopoietin-1; Angiopoietin-2; Diabetic Retinopathy; Endothelial Growth Factors; Eye; Fibroblast Growth Factors; Humans; Lymphokines; Macular Degeneration; Membrane Glycoproteins; Neovascularization, Pathologic; Proteins; Receptor Protein-Tyrosine Kinases; Receptors, Growth Factor; Receptors, Vascular Endothelial Growth Factor; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors | 2000 |
[Diabetic nephropathy and TGF-beta].
Topics: Animals; Biomarkers; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Glycation End Products, Advanced; Humans; Transforming Growth Factor beta | 1998 |
Growth factor alterations in advanced diabetic retinopathy: a possible role of blood retina barrier breakdown.
Chronic hyperglycemia may cause growth factor alterations that are likely to participate in tissue remodeling typical for diabetic late complications. However, few details of such events are known. The ocular vitreous fluid allows studies of growth factor levels in human eyes (after vitrectomy). The vitreous is highly inert and protected by the blood-retina barrier and thus probably reflects growth factor production by the normal retina. Vitreous from patients with proliferative diabetic retinopathy (PDR) was compared with vitreous obtained from patients with nonproliferative eye disease and with vitreous from patients without diabetes but with marked neovascular proliferations due to ischemia. This design permits us to distinguish diabetes-related from non-diabetes-related alterations. Insulin-like growth factor I (IGF-I), IGF-II, IGF binding protein 2 (IGFBP-2), and IGFBP-3 were elevated 3- to 13-fold in nondiabetic retinal ischemia and 1.5- to 3-fold in PDR, indicating that the changes were not restricted to diabetes. These changes may partially be explained by leakage of serum into the vitreous, since IGFs and IGFBPs are 20- to 50-fold higher in serum than in vitreous, and vitreous protein content was 1.5-fold elevated in PDR subjects and 5-fold in ischemia patients compared with control subjects. TGF-beta is a proposed antiangiogenic factor in the eye. TGF-beta2 was the predominant subtype in vitreous, and its total amount was not altered in PDR patients. More importantly, the active fraction of TGF-beta was decreased by 30 and 70% in PDR and nondiabetic retinal ischemia patients, respectively. Since plasmin may control TGF-beta activation, the serum protein alpha2-antiplasmin was measured and found to be significantly elevated to 150 and 250% of control values in PDR and ischemia patients, respectively. Thus, influx of serum proteins due to microvascular disturbances and hypoxia is proposed as a possible cause for vitreous alterations of IGF-I and of active TGF-beta. These changes seem to occur late in the sequence of events leading to PDR and are not specific for diabetes, but they were also observed in other diseases characterized by retinal hypoxia. Topics: alpha-2-Antiplasmin; Blood-Retinal Barrier; Diabetes Mellitus; Diabetic Retinopathy; Growth Substances; Humans; Insulin-Like Growth Factor Binding Protein 2; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Neovascularization, Pathologic; Transforming Growth Factor beta; Vitreous Body | 1997 |
[Functions of the transforming growth factor-beta superfamily in eyes].
One human body is composed of 6 x 10(13) cells, and eyes are also composed of many cells of different functions. The cellular functions and intercellular interaction are regulated by many regulators including cytokines and growth factors to maintain the homeostasis. The transforming growth factor-beta (TGF-beta) superfamily, a large family of multifunctional factors, regulates various cellular functions, including cellular proliferation, migration, differentiation, apoptosis and extracellular matrix production. The TGF-beta superfamily contains about 30 multifunctional factors, and is divided into several families according to the sequence homology. The TGF-beta family, the activin family, and bone morphogenic proteins belong to the TGF-beta superfamily. TGF-beta superfamily members transduce signals through type I and type II serine/threonine type transmembrane receptors. The signals are transduced from receptors through nuclei by Smad family members, which are phosphorylated by the activated type I receptors and translocate from cytoplasm into nuclei. TGF-beta family members and the TGF-beta superfamily receptor family are expressed in ocular tissues including the cornea, ciliary epithelium, lens epithelium, retina, and blood vessels. This observation suggests the importance of the TGF-beta superfamily in eyes. Smad family members (Smad 1, Smad 2, Smad 3 and Smad 4) are expressed in the cultured retinal pigmant epithelial cell line (D407), in which TGF-beta and activin A stimulate the translocation of Smad 2, but not Smad 1 into nuclei, whereas bone morphogenetic protein (BMP) stimulates that of Smad 1, but not Smad 2. TGF-beta superfamily members play important roles in the pathogenesis of retinal neovascularization and in the wound healing process of corneal tissue. TGF-beta inhibits the endothelial functions, but, stimulates angiogenesis in vivo. TGF-beta is involved in the formation of abnormal connective tissue in corneal wound healing. In these processes, many cytokines and growth factors are involved, interacting with each other and forming networks. It is mandatory to clarify the networks to investigate molecular pathogenesis and new therapeutic agents. Topics: Diabetic Retinopathy; Eye; Humans; Receptors, Transforming Growth Factor beta; Signal Transduction; Transforming Growth Factor beta | 1997 |
[Effective mechanisms of laser photocoagulation for neovascularization in diabetic retinopathy].
Effective mechanisms of laser photocoagulation for neovascularization in diabetic retinopathy were investigated in regard to change in oxygen pressure in the retina and vitreous and cytokines related to ischemia. The mechanism of laser photocoagulation is suggested to be as follows. 1. Destruction of the outer retina, especially of photoreceptors that have high oxygen consumption decreases metabolic function of the outer retina and its oxygen consumption. 2. The destruction allows increase of oxygen diffusion from choroidal vessels to inner retina, which improves the metabolic function by equilibrating oxygen demand and supply in the inner retina. (3) Production and secretion of neovascular factors such as vascular endothelial growth factor (VEGF) is decreased by the improvement of hypoxia. 4. The neovascularization is decreased by the synergistic effect between the neovascular factors and suppressors such an VEGF, fibroblast growth factor (FGF), and transforming growth factor-beta (TGF-beta). The improvement of the retinal ischemia and the decrease of cytokines are implicated in the regression of neovascularization by the laser photocoagulation for diabetic retinopathy. Topics: Animals; Choroid; Diabetic Retinopathy; Endothelial Growth Factors; Fibroblast Growth Factors; Humans; Light Coagulation; Lymphokines; Neovascularization, Pathologic; Oxygen Consumption; Partial Pressure; Retina; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors | 1996 |
Diabetic microvascular complications and growth factors.
Diabetes mellitus is associated with typical patterns of long term vascular complications which vary with the organ involved. The microvascular kidney disease (Olgemoller and Schleicher, 1993) is characterized by thickening of the capillary basement membranes and increased deposition of extracellular matrix components (ECM), while loss of microvessels with subsequent neovascularisation is predominant in the eye and peripheral nerves. On the other hand macrovascular disease is characterized by accelerated atherosclerosis. These complications are dependent on long term hyperglycemia. Specific biochemical pathways linking hyperglycaemia to microvascular changes were proposed: the polyol pathway (Greene et al., 1987), non-enzymatic glycation of proteins (Brownlee et al., 1988), glucose autooxidation and oxidative stress (Hunt et al., 1990), hyperglycemic pseudohypoxia (Williamson et al., 1993) enhanced activation of protein kinase C by de novo-synthesis of diacyl glycerol (Lee et al., 1989; DeRubertis and Craven 1994) and others. These pathways are not mutually exclusive (Larkins and Dunlop, 1992; Pfeiffer and Schatz, 1992). They may be linked to alterations in the synthesis of growth factors particularly since atherosclerosis and angioneogenesis are associated with increased proliferation of endothelial and smooth muscle cells. Increased synthesis of ECM components is stimulated by growth factors like transforming growth factor beta (TGF beta) (Derynck et al., 1984) and insulin-like growth factor I (IGF-I) (Moran et al., 1991). This review will summarize some of the recent evidence for an involvement of growth factors in diabetic vascular complications and will attempt to assign their emergence in the sequence of events leading to vascular complications. Topics: Animals; Arteriosclerosis; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Epidermal Growth Factor; Fibroblast Growth Factor 2; Growth Hormone; Growth Substances; Humans; Hyperglycemia; Insulin Resistance; Insulin-Like Growth Factor I; Receptors, Somatotropin; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha | 1995 |
1 trial(s) available for transforming-growth-factor-beta and Diabetic-Retinopathy
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Impact of dexamethasone and tocilizumab on hematological parameters in COVID-19 patients with chronic disease.
The most effective way to control severity and mortality rate of the novel coronavirus disease (COVID-19) is through sensitive diagnostic approaches and an appropriate treatment protocol. We aimed to identify the effect of adding corticosteroid and Tocilizumab to a standard treatment protocol in treating COVID-19 patients with chronic disease through hematological and lab biomarkers.. This study was performed retrospectively on 68 COVID-19 patients with chronic disease who were treated by different therapeutic protocols. The patients were categorized into four groups: control group represented the patients' lab results at admission before treatment protocols were applied; group 1 included patients treated with anticoagulants, Hydroxychloroquine, and antibiotics; group 2 comprised patients treated with Dexamethasone; and group 3 included patients treated with Dexamethasone and Tocilizumab.. The study paves the way into the effectiveness of combining Dexamethasone with Tocilizumab in treatment COVID-19 patients with chronic diseases.. La forma más eficaz de controlar la gravedad y la tasa de mortalidad de la enfermedad del nuevo coronavirus (COVID-19) es mediante enfoques de diagnóstico sensibles y un protocolo de tratamiento adecuado. Nuestro objetivo fue identificar el efecto de agregar corticosteroides y tocilizumab a un protocolo de tratamiento estándar en el tratamiento de pacientes con COVID-19 con enfermedad crónica a través de biomarcadores hematológicos y de laboratorio.. Este estudio se realizó de forma retrospectiva en 68 pacientes COVID-19 con enfermedad crónica que fueron tratados por diferentes protocolos terapéuticos. Los pacientes se clasificaron en cuatro grupos: el grupo de control representaba los resultados de laboratorio de los pacientes en el momento de la admisión antes de que se aplicaran los protocolos de tratamiento; el grupo 1 incluyó a pacientes tratados con anticoagulantes, hidroxicloroquina y antibióticos; el grupo 2 estaba compuesto por pacientes tratados con dexametasona; y el grupo 3 incluyó a pacientes tratados con dexametasona y tocilizumab.. El estudio allana el camino hacia la eficacia de la combinación de dexametasona con tocilizumab en el tratamiento de pacientes con COVID-19 con enfermedades crónicas.. The Child-Mother Index constitutes a potential useful risk factor indicator for statistical analyses on data after birth. The value of the Child-Mother Index based on the estimated fetal weight before birth deserves evaluation.. Six ceria supports synthesized by various synthesis methodologies were used to deposit cobalt oxide. The catalysts were thoroughly characterized, and their catalytic activity for complete methane oxidation was studied. The supports synthesized by direct calcination and precipitation with ammonia exhibited the best textural and structural properties as well as the highest degree of oxidation. The remaining supports presented poorer textural properties to be employed as catalytic supports. The cobalt deposited over the first two supports presented a good dispersion at the external surface, which induced a significant redox effect that increased the number of Co. Some studies show that children with obesity are more likely to receive a diagnosis of depression, anxiety, or attention-deficit hyperactivity disorder (ADHD). But this does not necessarily mean obesity causes these conditions. Depression, anxiety, or ADHD could cause obesity. A child's environment, including family income or their parents' mental health, could also affect a child's weight and mental health. Understanding the nature of these relationships could help scientists develop better interventions for both obesity and mental health conditions. Genetic studies may help scientists better understand the role of the environment in these conditions, but it's important to consider both the child's and their parents’ genetics in these analyses. This is because parents and children share not only genes, but also environmental conditions. For example, families that carry genetic variants associated with higher body weight might also have lower incomes, if parents have been affected by biases against heavier people in society and the workplace. Children in these families could have worse mental health because of effects of their parent’s weight, rather than their own weight. Looking at both child and adult genetics can help disentangle these processes. Hughes et al. show that a child's own body mass index, a ratio of weight and height, is not strongly associated with the child’s mental health symptoms. They analysed genetic, weight, and health survey data from about 41,000 8-year-old children and their parents. The results suggest that a child's own BMI does not have a large effect on their anxiety symptoms. There was also no clear evidence that a child's BMI affected their symptoms of depression or ADHD. These results contradict previous studies, which did not account for parental genetics. Hughes et al. suggest that, at least for eight-year-olds, factors linked with adult weight and which differ between families may be more critical to a child's mental health than a child’s own weight. For older children and adolescents, this may not be the case, and the individual’s own weight may be more important. As a result, policies designed to reduce obesity in mid-childhood are unlikely to greatly improve the mental health of children. On the other hand, policies targeting the environmental or societal factors contributing to higher body weights, bias against people with higher weights, and poor child mental health directly may be more beneficial.. The development of an efficient photocatalyst for C2 product formation from CO. Оценка антиастенического эффекта последовательной терапии левокарнитином (ЛК) и ацетилкарнитином (АЛК) пациентов с артериальной гипертензией и/или ишемической болезнью сердца (ИБС) с астеническим синдромом (АС).. В открытое сравнительное исследование были включены 120 пациентов в возрасте 54—67 лет с артериальной гипертензией и/или ИБС с АС. Пациенты 1-й группы (. У больных 1-й группы отмечено статистически значимое уменьшение различных проявлений АС. Отличия носили достоверный характер по сравнению как с исходным уровнем, так и со 2-й группой. Установлено эндотелийпротективное действие ЛК и АЛК.. Полученные результаты свидетельствуют, что у таких коморбидных пациентов использование ЛК и АЛК уменьшает выраженность проявлений АС, а установленные эндотелиотропные свойства препаратов позволяют рекомендовать их в составе комплексной персонифицированной терапии пациентов с сердечно-сосудистыми заболеваниями.. Naproxen sodium 440 mg/diphenhydramine 50 mg combination demonstrated improvement in sleep maintenance (WASO) vs. naproxen sodium 550 mg and higher efficiency in average daily pain reduction compared with the comparison groups. The treatment was well tolerated There were no serious or unexpected adverse events reported in the study.. Сравнительный анализ эффективности и безопасности новой комбинации напроксена натрия и дифенгидрамина у пациентов с неспецифическим болевым синдромом в пояснично-крестцовом отделе спины (M54.5 «Боль внизу спины») и нарушением сна (G47.0 «Нарушения засыпания и поддержания сна [бессонница]»).. Проведено проспективное многоцентровое рандомизированное открытое сравнительное в параллельных группах клиническое исследование. Пациенты были рандомизированы в 3 группы. Больные 1-й группы получали напроксен натрия (440 мг) и дифенгидрамин (50 мг), 2-й — напроксен натрия (550 мг), 3-й — парацетамол (1000 мг) и дифенгидрамин (50 мг). Исследуемые препараты пациенты принимали однократно перед сном в течение 3 дней. Все пациенты также принимали 275 мг (1 таблетка) напроксена натрия в качестве препарата фоновой терапии. Первичным критерием эффективности было общее время бодрствования после наступления сна (WASO), измеряемое методом актиграфии. Также использовались критерии оценки продолжительности и качества сна и выраженности боли.. Анализ эффективности проведен для ITT популяции (. Применение комбинации напроксена натрия (440 мг) и дифенгидрамина (50 мг) характеризовалось более выраженным поддержанием сна по сравнению с напроксеном натрия 550 мг и более высокой эффективностью в отношении снижения интенсивности боли по сравнению со 2-й и 3-й группами. Отмечена хорошая переносимость препарата, серьезных нежелательных явлений зарегистрировано не было. Topics: Acetaminophen; Acetylcarnitine; Acetylcholinesterase; Acids; Acinetobacter baumannii; Acinetobacter Infections; Adaptation, Psychological; Adolescent; Adsorption; Adult; Aged; Alcohol Drinking; Alzheimer Disease; Amikacin; Ammonia; Anaerobiosis; Animals; Anorexia; Anti-Bacterial Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Anxiety; Aptamers, Nucleotide; Asthenia; Attention Deficit Disorder with Hyperactivity; Bacterial Proteins; Beryllium; beta-Lactamases; Biofuels; Biomass; Biosensing Techniques; Bismuth; Blister; Body Mass Index; Body Surface Area; Boronic Acids; Brain; Breast Neoplasms; Butyrylcholinesterase; Cannabis; Carbapenems; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Carboxylic Acids; Carcinoma, Hepatocellular; Cardiovascular Diseases; Carnitine; Case-Control Studies; Catalysis; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Child; China; Cholinesterase Inhibitors; Clarithromycin; Clostridioides; Clostridioides difficile; Clostridium Infections; Cohort Studies; Colistin; Colitis; Colon; Coloring Agents; Coronary Artery Bypass; Creatinine; Crystalloid Solutions; Cytokines; Depression; Dextran Sulfate; Dextrans; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Diarrhea; Dietary Supplements; Diphenhydramine; Disease Models, Animal; Disease Outbreaks; Double-Blind Method; Doxorubicin; Drosophila; Drug Tapering; Dysbiosis; Electrons; Escherichia coli; Extracellular Vesicles; Fatigue; Female; Fermentation; gamma-Cyclodextrins; Gastrointestinal Microbiome; Glucose; Graft Survival; Graft vs Host Disease; Head and Neck Neoplasms; Heart Arrest, Induced; Hematopoietic Stem Cell Transplantation; High-Intensity Interval Training; Hippocampus; Humans; Hydrogen-Ion Concentration; Hypertension; Incidence; Interferon-gamma; Italy; Kinetics; Klebsiella Infections; Klebsiella pneumoniae; Lab-On-A-Chip Devices; Lactoferrin; Larva; Length of Stay; Lignin; Liver; Liver Neoplasms; Liver Transplantation; Living Donors; Low Back Pain; Lung; Lung Volume Measurements; Macrophages; Male; Melphalan; Men; Mendelian Randomization Analysis; Meropenem; Methane; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Mitochondrial Proteins; Molecular Docking Simulation; Molecular Structure; Mothers; Motivation; Mycoplasma; Mycoplasma hominis; Mycoplasma Infections; NAD; Nanocomposites; Nanoparticles; Nanotubes, Carbon; Naproxen; Neovascularization, Pathologic; Neurons; Nitrates; Nucleolin; Opuntia; Paratyphoid Fever; Phenotype; Phosphatidylinositol 3-Kinases; Phytochemicals; Plant Extracts; Pregnancy; Prevalence; Prospective Studies; Proto-Oncogene Proteins c-akt; Pulmonary Disease, Chronic Obstructive; Rats; Rats, Wistar; Resveratrol; Retrospective Studies; Rifampin; Risk Factors; RNA, Messenger; Selenium; Sleep; Social Behavior; Soil; Soil Pollutants; Squamous Cell Carcinoma of Head and Neck; Staphylococcus aureus; Structure-Activity Relationship; Suicidal Ideation; Suicide; Superoxide Dismutase-1; Surveys and Questionnaires; Swimming; Syndrome; Tannins; Temperature; Transforming Growth Factor beta; Transplantation Conditioning; Treatment Outcome; Triple Negative Breast Neoplasms; Troponin T; Tumor Microenvironment; United Kingdom; Ureaplasma; Ureaplasma urealyticum; Urinary Tract Infections; Viscum; Waste Disposal Facilities; Wastewater; Water; Water Pollutants, Chemical; Wolfiporia; Young Adult | 2022 |
45 other study(ies) available for transforming-growth-factor-beta and Diabetic-Retinopathy
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Effects of the Calix[4]arene Derivative Compound OTX008 on High Glucose-Stimulated ARPE-19 Cells: Focus on Galectin-1/TGF-β/EMT Pathway.
Diabetic retinopathy (DR) is a neurovascular disease characterized by the reduction of retina integrity and functionality, as a consequence of retinal pigment epithelial cell fibrosis. Although galectin-1 (a glycan-binding protein) has been associated with dysregulated retinal angiogenesis, no evidence has been reported about galectin-1 roles in DR-induced fibrosis. ARPE-19 cells were cultured in normal (5 mM) or high glucose (35 mM) for 3 days, then exposed to the selective galectin-1 inhibitor OTX008 (2.5-5-10 μM) for 6 days. The determination of cell viability and ROS content along with the analysis of specific proteins (by immunocytochemistry, Western blotting, and ELISA) or mRNAs (by real time-PCR) were performed. OTX008 5 μM and 10 μM improved cell viability and markedly reduced galectin-1 protein expression in cells exposed to high glucose. This was paralleled by a down-regulation of the TGF-β/, NF-kB p65 levels, and ROS content. Moreover, epithelial-mesenchymal transition markers were reduced by OTX008 5 μM and 10 μM. The inhibition of galectin-1 by OTX008 in DR may preserve retinal pigment epithelial cell integrity and functionality by reducing their pro-fibrotic phenotype and epithelial-mesenchymal transition phenomenon induced by diabetes. Topics: Calixarenes; Diabetic Retinopathy; Epithelial Cells; Epithelial-Mesenchymal Transition; Fibrosis; Galectin 1; Glucose; Humans; Phenols; Reactive Oxygen Species; Retinal Pigment Epithelium; Retinal Pigments; Transforming Growth Factor beta | 2022 |
GDF11 protects against glucotoxicity-induced mice retinal microvascular endothelial cell dysfunction and diabetic retinopathy disease.
Growth differentiation factor 11 (GDF11) has been implicated in the regulation of embryonic development and age-related dysfunction, including the regulation of retinal progenitor cells. However, little is known about the functions of GDF11 in diabetic retinopathy. In this study, we demonstrated that GDF11 treatment improved diabetes-induced retinal cell death, capillary degeneration, pericyte loss, inflammation, and blood-retinal barrier breakdown in mice. Treatment of isolated mouse retinal microvascular endothelial cells with recombinant GDF11 in vitro attenuated glucotoxicity-induced retinal endothelial apoptosis and the inflammatory response. The protective mechanisms exerted are associated with TGF-β/Smad2, PI3k-Akt-FoxO1 activation,and NF-κB pathway inhibition. This study indicated that GDF11 is a novel therapeutic target for diabetic retinopathy. Topics: Animals; Apoptosis; Blood-Retinal Barrier; Bone Morphogenetic Proteins; Cytokines; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Endothelial Cells; Forkhead Box Protein O1; Glucose; Growth Differentiation Factors; Inflammation; Male; Mice, Inbred C57BL; Microvessels; Neuroprotective Agents; NF-kappa B; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Retina; Signal Transduction; Smad Proteins; Transforming Growth Factor beta | 2021 |
Relationship between elevated microRNAs and growth factors levels in the vitreous of patients with proliferative diabetic retinopathy.
The aim of this study was to identify differentially expressed microRNAs (miRNAs) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and correlate some of them with growth factors.. Vitreous samples were collected from 5 PDR eyes and 5 control eyes, and then miRNAs were assayed with next-generation sequencing (NGS). Three differentially expressed miRNAs were validated in vitreous of another cohort using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR).. Transforming growth factor β (TGF-β) and vascular endothelial growth factor (VEGF) signaling pathway were excavated out through bioinformatic analysis of deregulated miRNAs. The expression of hsa-miR-24-3p, hsa-miR-197-3p and hsa-miR-3184-3p, VEGF-A and TGF-β were confirmed to be significantly higher in the vitreous of PDR eyes than controls(P < 0.05). Furthermore, Pearson's correlation analysis showed significantly positive correlations between these elevated miRNAs and growth factors (P < 0.05).. Elevated vitreous levels of hsa-miR-24-3p, hsa-miR-197-3p, hsa-miR-3184-3p in PDR patients may play roles in pathophysiology of PDR, the target mRNAs of which significantly enriched in VEGF and TGF-β signaling pathways. Positive correlations between elevated vitreous levels of the three miRNAs and VEGF-A, TGF-β in PDR patients could provide a novel research direction for PDR. Topics: Diabetes Mellitus; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Humans; MicroRNAs; Signal Transduction; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vitreous Body | 2021 |
Increased levels of cytokines in the aqueous humor correlate with the severity of diabetic retinopathy.
To determine the associations between the levels of certain cytokines in the aqueous humor and the severity of diabetic retinopathy.. A total of 103 patients (one eye per patient) who received intravitreal injection with ranibizumab for diabetic retinopathy were enrolled and divided into 3 groups: nonproliferative diabetic retinopathy (NPDR) with macular edema group (42 eyes), proliferative diabetic retinopathy (PDR) group (40 eyes) and neovascular glaucoma due to PDR (NVG-PDR) group (21 eyes). The concentrations of interleukin (IL)-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemoattractant protein-1 (MCP-1) in the aqueous humor were measured.. In this study, 42, 40 and 21 patients (one eye per patient) were included in the NPDR, PDR and NVG-PDR groups, respectively. The median concentrations of IL-6, IL-8, IL-10, VEGF, TGF-β, VCAM-1, ICAM-1 and MCP-1 in the groups were measured. The levels of these 8 cytokines increased with the severity of diabetic retinopathy, especially in the NVG-PDR group. Compared with those in the NPDR group, the aqueous concentrations of these 8 cytokines were higher in the PDR group and were the highest in the NVG-PDR group. There were significant differences in all cytokines among the three groups (P < 0.05). Multivariate analysis showed that in the NPDR and PDR groups, the risk of PDR associated with elevated levels of TGF-β (P = 0.0004, OR 1.11, 95% CI [1.05-1.18]) and ICAM-1 (P = 0.0408, OR 10.75, 95% CI [1.10-104.61]). In the PDR and NVG groups, the risk of NVG associated with elevated levels of IL-10 (P = 0.0486, OR 0.7040, 95% CI [0.4966, 0.9979]), VEGF (P = 0.0279, OR 0.9963, 95% CI [0.9931, 0.9996]), and VCAM-1 (P = 0.0316, OR 0.9998, 95% CI [0.9996, 0.99998]). In the three groups, the risk of developing NVG associated with elevated levels of TGF-β (P < 0.001, OR 1.04, 95% CI [1.02, 1.05]).. The levels of these eight cytokines in the aqueous humor increased with the severity of diabetic retinopathy, especially in NVG-PDR. This study suggests that TGF-β, ICAM-1, IL-10, VEGF, and VCAM-1 may play a role in the progression of diabetic retinopathy, especially TGF-β, which may plays a significant role in NVG-PDR. These cytokines potentially may be used as biomarkers to predict the progress of diabetic retinopathy, contribute to the choice of treatment options and/or monitor treatment responses. Topics: Aqueous Humor; Chemokine CCL2; Cytokines; Diabetes Mellitus; Diabetic Retinopathy; Glaucoma, Neovascular; Humans; Intercellular Adhesion Molecule-1; Interleukin-10; Interleukin-6; Interleukin-8; Macular Edema; Ranibizumab; Transforming Growth Factor beta; Vascular Cell Adhesion Molecule-1; Vascular Endothelial Growth Factor A | 2020 |
RNA-Seq reveals placental growth factor regulates the human retinal endothelial cell barrier integrity by transforming growth factor (TGF-β) signaling.
Placental growth factor (PlGF or PGF) is a member of the VEGF (vascular endothelial growth factor) family. It plays a pathological role in inflammation, vascular permeability, and pathological angiogenesis. The molecular signaling by which PlGF mediates its effects in non-proliferative diabetic retinopathy (DR) remains elusive. This study aims to characterize the transcriptome changes of human retinal endothelial cells (HRECs) with the presence and the absence of PlGF signaling. Primary HRECs were treated with the PlGF antibody (ab) to block its activity. The total RNA was isolated and subjected to deep sequencing to quantify the transcripts and their changes in both groups. We performed transcriptome-wide analysis, gene ontology, pathway enrichment, and gene-gene network analyses. The results showed that a total of 3760 genes were significantly differentially expressed and were categorized into cell adhesion molecules, cell junction proteins, chaperone, calcium-binding proteins, and membrane traffic proteins. Functional pathway analyses revealed that the TGF-β pathway, pentose phosphate pathway, and cell adhesion pathway play pivotal roles in the blood-retina barrier and antioxidant defense system. Collectively, the data provide new insights into the molecular mechanisms of PlGF's biological functions in HRECs relevant to DR and diabetic macular edema (DME). The newly identified genes and pathways may act as disease markers and target molecules for therapeutic interventions for the patients with DR and DME refractory to the current anti-VEGF therapy. Topics: Cells, Cultured; Diabetic Retinopathy; Endothelial Cells; Gene Expression Regulation; Humans; Placenta Growth Factor; Retina; Retinal Vessels; RNA-Seq; Signal Transduction; Transforming Growth Factor beta | 2020 |
TGF-β Serum Levels in Diabetic Retinopathy Patients and the Role of Anti-VEGF Therapy.
Transforming growth factor β1 (TGFβ1) is a proinflammatory cytokine that has been implicated in the pathogenesis of diabetic retinopathy (DR), particularly in the late phase of disease. The aim of the present study was to validate serum TGFβ1 as a diagnostic and prognostic biomarker of DR stages. Thirty-eight subjects were enrolled and, after diagnosis and evaluation of inclusion and exclusion criteria, were assigned to six groups: (1) healthy age-matched control, (2) diabetic without DR, (3) non-proliferative diabetic retinopathy (NPDR) naïve to treatment, (4) NPDR treated with intravitreal (IVT) aflibercept, (5) proliferative diabetic retinopathy (PDR) naïve to treatment and (6) PDR treated with IVT aflibercept. Serum levels of vascular endothelial growth factor A (VEGF-A), placental growth factor (PlGF) and TGFβ1 were measured by means of enzyme-linked immunosorbent assay (ELISA). Foveal macular thickness (FMT) in enrolled subjects was evaluated by means of structural-optical coherence tomography (S-OCT). VEGF-A serum levels decreased in NPDR and PDR patients treated with aflibercept, compared to naïve DR patients. PlGF serum levels were modulated only in aflibercept-treated NPDR patients. Particularly, TGFβ1 serum levels were predictive of disease progression from NPDR to PDR. A Multivariate ANOVA analysis (M-ANOVA) was also carried out to assess the effects of fixed factors on glycated hemoglobin (HbA1c) levels, TGFβ1, and diabetes duration. In conclusion, our data have strengthened the hypothesis that TGFβ1 would be a biomarker and pharmacological target of diabetic retinopathy. Topics: Aged; Aged, 80 and over; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Humans; Intercellular Signaling Peptides and Proteins; Male; Molecular Targeted Therapy; ROC Curve; Tomography, Optical Coherence; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A | 2020 |
Involvement of Müller Glial Autoinduction of TGF-β in Diabetic Fibrovascular Proliferation Via Glial-Mesenchymal Transition.
Müller glial-mesenchymal transition (GMT) is reported as the fibrogenic mechanism promoted by TGF-β-SNAIL axis in Müller cells transdifferentiated into myofibroblasts. Here we show the multifaceted involvement of TGF-β in diabetic fibrovascular proliferation via Müller GMT and VEGF-A production.. Surgically excised fibrovascular tissues from the eyes of patients with proliferative diabetic retinopathy were processed for immunofluorescence analyses of TGF-β downstream molecules. Human Müller glial cells were used to evaluate changes in gene and protein expression with real-time quantitative PCR and ELISA, respectively. Immunoblot analyses were performed to detect TGF-β signal activation.. Müller glial cells in patient fibrovascular tissues were immunopositive for GMT-related molecular markers, including SNAIL and smooth muscle protein 22, together with colocalization of VEGF-A and TGF-β receptors. In vitro administration of TGF-β1/2 upregulated TGFB1 and TGFB2, both of which were suppressed by inhibitors for nuclear factor-κB, glycogen synthase kinase-3, and p38 mitogen-activated protein kinase. Of the various profibrotic cytokines, TGF-β1/2 application exclusively induced Müller glial VEGFA mRNA expression, which was decreased by pretreatment with small interfering RNA for SMAD2 and inhibitors for p38 mitogen-activated protein kinase and phosphatidylinositol 3-kinase. Supporting these findings, TGF-β1/2 stimulation to Müller cells increased the phosphorylation of these intracellular signaling molecules, all of which were also activated in Müller glial cells in patient fibrovascular tissues.. This study underscored the significance of Müller glial autoinduction of TGF-β as a pathogenic cue to facilitate diabetic fibrovascular proliferation via TGF-β-driven GMT and VEGF-A-driven angiogenesis. Topics: Cell Transdifferentiation; Cells, Cultured; Cytokines; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Ependymoglial Cells; Fluorescent Antibody Technique; Humans; Real-Time Polymerase Chain Reaction; Signal Transduction; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A | 2020 |
Aqueous humour concentrations of TGF-β, PLGF and FGF-1 and total retinal blood flow in patients with early non-proliferative diabetic retinopathy.
Topics: Aqueous Humor; Biomarkers; Diabetic Retinopathy; Fibroblast Growth Factor 1; Humans; Placenta Growth Factor; Regional Blood Flow; Transforming Growth Factor beta | 2019 |
Proteotoxic Stress Desensitizes TGF-beta Signaling Through Receptor Downregulation in Retinal Pigment Epithelial Cells.
Proteotoxic stress and transforming growth factor (TGFβ)- induced epithelial-mesenchymal transition (EMT) are two main contributors of intraocular fibrotic disorders, including proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). However, how these two factors communicate with each other is not well-characterized.. The aim was to investigate the regulatory role of proteotoxic stress on TGFβ signaling in retinal pigment epithelium.. ARPE-19 cells and primary human retinal pigment epithelial (RPE) cells were treated with proteasome inhibitor MG132 and TGFβ. Cell proliferation was analyzed by CCK-8 assay. The levels of mesenchymal markers α-SMA, fibronectin, and vimentin were analyzed by real-time polymerase chain reaction (PCR), western blot, and immunofluorescence. Cell migration was analyzed by scratch wound assay. The levels of p-Smad2, total Smad2, p-extracellular signal-regulated kinase 1/2 (ERK1/2), total ERK1/2, p-focal adhesion kinase (FAK), and total FAK were analyzed by western blot. The mRNA and protein levels of TGFβ receptor-II (TGFβR-II) were measured by realtime PCR and western blot, respectively.. MG132-induced proteotoxic stress resulted in reduced cell proliferation. MG132 significantly suppressed TGFβ-induced upregulation of α-SMA, fibronectin, and vimentin, as well as TGFβ-induced cell migration. The phosphorylation levels of Smad2, ERK1/2, and FAK were also suppressed by MG132. Additionally, the mRNA level and protein level of TGFβR-II decreased upon MG132 treatment.. Proteotoxic stress suppressed TGFβ-induced EMT through downregulation of TGFβR-II and subsequent blockade of Smad2, ERK1/2, and FAK activation. Topics: Cell Movement; Cell Proliferation; Diabetic Retinopathy; Epithelial-Mesenchymal Transition; Focal Adhesion Kinase 1; Gene Expression Regulation; Humans; Leupeptins; MAP Kinase Signaling System; Primary Cell Culture; Proteasome Endopeptidase Complex; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Retinal Pigment Epithelium; Smad2 Protein; Transforming Growth Factor beta; Vitreoretinopathy, Proliferative | 2017 |
Aqueous humour concentrations of TGF-β, PLGF and FGF-1 and total retinal blood flow in patients with early non-proliferative diabetic retinopathy.
To correlate angiogenic cytokines in the aqueous humour with total retinal blood flow in subjects with type 2 diabetes with non-proliferative diabetic retinopathy (NPDR).. A total of 17 controls and 16 NPDR patients were recruited into the study. Aqueous humour was collected at the start of cataract surgery to assess the concentration of 14 angiogenic cytokines. Aqueous humour was analysed using the suspension array method. Six images were acquired to assess total retinal blood flow (TRBF) using the prototype RTVue. Transforming growth factor beta (TGF-β1, TGF-β2) and PLGF were increased while FGF-1 was reduced in NPDR compared to controls (Bonferroni corrected, p < 0.003 for all). Total retinal blood flow (TRBF) was significantly reduced in the NPDR group compared to controls (33.1 ± 9.9 versus 43.3 ± 5.3 μl/min, p = 0.002). Aqueous FGF-1 significantly correlated with TRBF in the NPDR group (r = 0.71, p = 0.01; r. Aqueous angiogenic cytokines (TGF-β1, TGF-β2 and PLGF) were elevated in conjunction with a reduction in TRBF in patients with NPDR compared to controls. Non-invasive measurement of TRBF may be useful for predicting aqueous FGF-1 levels and severity of vasculopathy in DR. Topics: Aged; Aqueous Humor; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Fibroblast Growth Factor 1; Humans; Male; Placenta Growth Factor; Regional Blood Flow; Retinal Vessels; Tomography, Optical Coherence; Transforming Growth Factor beta | 2017 |
Upregulation of Mir-21 Levels in the Vitreous Humor Is Associated with Development of Proliferative Vitreoretinal Disease.
MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression by post-transcriptional inhibition of mRNA translation. Dysregulation of miRNAs, including circulating miRNAs, has been reported to play an important role in the development of various diseases, including fibrotic diseases. Aberrant expression of miRNAs in the vitreous humor of vitreoretinal diseased eyes has been reported. However, the expression pattern of miRNAs present in the vitreous humor of proliferative vitreoretinal disease (PVD) patients, including proliferative diabetic retinopathy (PDR), and proliferative vitreoretinopathy (PVR), remains unknown. To investigate the factors important for the development of PVD, we characterized the miRNAs present in the vitreous humor of PVD patients and analyzed the expression profiles of 377 miRNAs using quantitative polymerase chain reaction-based miRNA arrays. The expression of a specific subset of miRNAs, previously reported to be associated with the development of angiogenesis and fibrosis, was significantly altered in the vitreous of PVD patients. Among these miRNAs, we identified miR-21 as a candidate fibrotic miRNA with an important role in the pathogenesis of PVD. Increased miR-21 levels in the vitreous were associated with retinal fibrosis, including PVR and PDR. Because epithelial-mesenchymal transition (EMT) of retinal pigment epithelial cells (RPECs) plays a critical role in retinal fibrosis, the expression of miR-21 in human RPECs was determined. Its expression in RPECs was induced by transforming growth factor-β, a key growth factor involved in fibrogenesis, and was enhanced by high glucose culture conditions, suggesting that miR-21 expression positively correlates with disease progression. Gain- and loss-of-function studies revealed that miR-21 promoted cell proliferation and migration of ARPE-19 cells without affecting EMT-related gene expression. Together, our studies have identified miR-21 as a potential disease-modifying miRNA in the vitreous humor that is involved in the development of retinal fibrosis and may be a novel marker of PVD. Topics: Aged; Case-Control Studies; Cell Line; Cell Movement; Cell Proliferation; Diabetic Retinopathy; Female; Humans; Male; MicroRNAs; Middle Aged; Retinal Pigment Epithelium; Transforming Growth Factor beta; Up-Regulation; Vitreous Body | 2016 |
TGFβ induces BIGH3 expression and human retinal pericyte apoptosis: a novel pathway of diabetic retinopathy.
Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Arterioles; Blotting, Western; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Extracellular Matrix Proteins; Humans; Macrophages; Pericytes; Polymerase Chain Reaction; Retina; Retinal Vessels; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2 | 2016 |
Deletion of ocular transforming growth factor β signaling mimics essential characteristics of diabetic retinopathy.
Diabetic retinopathy, a major cause of blindness, is characterized by a distinct phenotype. The molecular causes of the phenotype are not sufficiently clear. Here, we report that deletion of transforming growth factor β signaling in the retinal microenvironment of newborn mice induces changes that largely mimic the phenotype of nonproliferative and proliferative diabetic retinopathy in humans. Lack of transforming growth factor β signaling leads to the formation of abundant microaneurysms, leaky capillaries, and retinal hemorrhages. Retinal capillaries are not covered by differentiated pericytes, but by a coat of vascular smooth muscle-like cells and a thickened basal lamina. Reactive microglia is found in close association with retinal capillaries. In older animals, loss of endothelial cells and the formation of ghost vessels are observed, findings that correlate with the induction of angiogenic molecules and the accumulation of retinal hypoxia-inducible factor 1α, indicating hypoxia. Consequently, retinal and vitreal neovascularization occurs, a scenario that leads to retinal detachment, vitreal hemorrhages, neuronal apoptosis, and impairment of sensory function. We conclude that transforming growth factor β signaling is required for the differentiation of retinal pericytes during vascular development of the retina. Lack of differentiated pericytes initiates a scenario of structural and functional changes in the retina that mimics those of diabetic retinopathy strongly indicating a common mechanism. Topics: Animals; Apoptosis; Cell Differentiation; Diabetic Retinopathy; Mice; Mice, Transgenic; Pericytes; Retinal Neovascularization; Retinal Vessels; Signal Transduction; Transforming Growth Factor beta | 2015 |
Regulatory T cells in the pathogenesis of type 2 diabetes mellitus retinopathy by miR-155.
To explore the regulatory T cells (Treg) in the peripheral blood of diabetic retinopathy patients by microRNA-155 (miR-155), and investigate the mechanisms of regulatory T cells and miR-155 in the pathogenesis of diabetic retinopathy.. The study explores the percentage of CD4+ CD25+ Foxp3+ T cells (Treg cells) and the expression of miR-155 in the peripheral blood of 20 cases with background diabetic retinopathy (BDR group) and 20 cases with proliferative diabetic retinopathy (PDR group). Flow cytometry and RT-PCR determined 18 cases with non-diabetic retinopathy (NDR group) and 20 cases of healthy control (NC group). ELISA determined the expression of TGF-β.. The percentages of Treg cells in the peripheral blood of patients in BDR group, PDR group, and NDR group had significantly decreased compared to that in the NC group (p < 0.05). The percentages of the Treg cells in the BDR and PDR groups were lower than those in NDR group (p < 0.05 in both cases). The percentage of Treg cells in the PDR group was lower than that in the BDR group (p < 0.05). The expression levels of miR-155 in the peripheral blood of the patients in the BDR group, PDR group, and NDR group had significantly increased compared to that in NC group (p < 0.05). The expression levels of miR-155 in the BDR group and PDR group were higher than that in the NDR group (p < 0.05 in both cases). The expression level of miR-155 in the PDR group was higher than that in the BDR group (p < 0.05). The expression levels of TGF-β in the BDR group and PDR group were significantly decreased compared to those in the NDR group and NC group (p < 0.05 in both cases). The expression of miR-155 was negatively related to the Treg cells and the expression level of TGF-β2 (r1 = -0.835, p1 = 0.000, r2 = -0.771, p2 = 0.000).. In type 2 diabetes mellitus (T2DM) retinopathy, miR-155 may play an important role in the pathogenesis of T2DM retinopathy by regulating the Treg cells with TGF-β. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Flow Cytometry; Humans; Lymphocyte Count; Male; MicroRNAs; Middle Aged; T-Lymphocytes, Regulatory; Transforming Growth Factor beta | 2015 |
A possible role of acrolein in diabetic retinopathy: involvement of a VEGF/TGFβ signaling pathway of the retinal pigment epithelium in hyperglycemia.
Acrolein has been implicated in retinal pigment epithelium (RPE) cell death, and has been associated with diabetic retinopathy. Our purpose was to investigate the potential effect of high glucose in influencing acrolein-mediated RPE cytokine production and cell death. We investigated the influence of the acrolein effect on ARPE-19 cells in high glucose conditions and quantified the release of transforming growth factor β (TGFβ1 and 2) and vascular endothelial growth factor (VEGF). We assessed the ability of N-benzylhydroxylamine(NBHA) as well as TGFβ pathway inhibitors SIS3 and SB431542 to prevent this effect of acrolein on ARPE-19 cells.. Confluent ARPE-19 cells were treated with acrolein and/or NBHA in both 5.5 and 18.8 mM glucose conditions. Cells were also pretreated with SIS3, a specific inhibitor of the SMAD3 pathway, and SB431542, a specific inhibitor of TGFβ signaling pathway, before treating them with acrolein. Viable cells were counted and ELISAs were performed to measure the cytokines TGFβ1 and 2, and VEGF released into the conditioned media.. In ARPE-19 cells exposed to acrolein and hyperglycemia there was reduced cell viability and an increase in the cell media of VEGF, TGFβ1, and TGFβ2, which was reversed by NBHA. Acrolein/hyperglycemia-induced cell viability reduction and cytokine overproduction was also reduced by TGFβ pathway blockade.. We conclude that the effect of acrolein on the reduction of viability and VEGF increase by ARPE-19 cells in hyperglycemic media is conducted through the TGFβ signaling pathway. Our results suggest that benefits of sequestering acrolein by NBHA and the blockage of the TGFβ pathway by SB431542 and SIS3 offer suggestions as to potential useful pharmacological drug candidates for the prevention of diabetes-induced complications in the eye. Topics: Acrolein; Cell Line; Cell Survival; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Humans; Hyperglycemia; Retinal Pigment Epithelium; Signal Transduction; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A | 2012 |
Association of vascular endothelial growth factor, transforming growth factor beta, and interferon gamma gene polymorphisms with proliferative diabetic retinopathy in patients with type 2 diabetes.
Chronic hyperglycemia and hypoxemia are believed to be causal factors in the development of proliferative diabetic retinopathy (PDR) among individuals with type 2 diabetes. It is hypothesized that formation of new blood vessels in the retina due to prolonged hypoxia is associated with increased expression of several growth factors and angiogenic cytokines. In the present study, we investigated the association of genetic polymorphisms in vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-β), and interferon γ (IFN-γ) genes, which may be responsible for the hypoxia-induced VEGF-mediated neovascularization pathway for the pathogenesis of PDR.. Our case-control association study composed of 493 ethnically matched volunteers (253 with PDR [cases] and 240 diabetic controls [DC]). Gene polymorphisms were determined with Taqman-based real-time PCR and amplification refractory mutation analysis system PCR.. The VEGF-460C (rs833061C; p=0.0043) and IFN-γ +874T (rs2430561T; p=0.0011) alleles were significantly associated with PDR.. Genetic variations at VEGF-460C and IFN-γ +874T might accelerate the pathogenesis of retinal neovascularization in PDR. Topics: Adult; Aged; Alleles; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Gene Frequency; Humans; Interferon-gamma; Male; Middle Aged; Polymorphism, Single Nucleotide; Real-Time Polymerase Chain Reaction; Retina; Retinal Neovascularization; Sequence Analysis, DNA; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A | 2012 |
Differential TGF-{beta} signaling in retinal vascular cells: a role in diabetic retinopathy?
Purpose. An early hallmark of preclinical diabetic retinopathy is thickening of the capillary basal lamina (BL). TGF-beta, a multipotent cytokine acting through its receptors ALK5 and -1, has been postulated to be involved in this phenomenon. In light of this possible role, TGF-beta signaling and its downstream molecular effects were characterized in cultured vascular endothelial cells and pericytes of the retina. Methods. Bovine retinal endothelial cells and pericytes were stimulated with TGF-beta1 in the presence or absence of SD-208, a specific inhibitor of the TGF-beta type I receptor ALK5, or ALK5 small interfering (si)RNA. TGF-beta-signaling pathways were characterized by analysis of phosphorylated Smad2 or -1/5/8 proteins and TGF-beta target genes (PAI-1, fibronectin, CTGF, Smad7, and Id1) and protein (fibronectin). Results. ALK5 was expressed in both cell types, whereas ALK1 was exclusively expressed in endothelial cells. In endothelial cells, TGF-beta induced Smad2 phosphorylation at high concentrations, which was efficiently blocked by ALK5 inhibition. In contrast, in pericytes, Smad2 phosphorylation was rapidly induced at low concentrations of TGF-beta. The ALK1-Smad1/5/8 pathway was activated by TGF-beta in endothelial cells only. TGF-beta caused ALK5-mediated upregulation of PAI-1, Smad7, and fibronectin and in pericytes at lower TGF-beta concentrations than in endothelial cells. CTGF mRNA expression was induced only in pericytes. Fibronectin protein was confirmed to be regulated by TGF-beta in both cell types. Conclusions. TGF-beta signaling in retinal endothelial cells and pericytes show that these cells, and in particular the pericytes, have the essential characteristics to allow for a role of TGF-beta in BL thickening in preclinical diabetic retinopathy. Topics: Animals; Blotting, Western; Cattle; Cells, Cultured; Diabetic Retinopathy; Endothelium, Vascular; Fibronectins; Pericytes; Phosphorylation; Plasminogen Activator Inhibitor 1; Protein Serine-Threonine Kinases; Pteridines; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; Retinal Vessels; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Smad2 Protein; Smad7 Protein; Transforming Growth Factor beta | 2010 |
Expression of advanced glycation end products and related molecules in diabetic fibrovascular epiretinal membranes.
To investigate associations between expressions of advanced glycation end products (AGEs), transforming growth factor-beta (TGF-beta), tumour necrosis factor-alpha (TNF-alpha) and integrins and correlations between their expression and level of vascularization and proliferative activity in diabetic fibrovascular epiretinal membranes.. Membranes from eight patients with active proliferative diabetic retinopathy and nine patients with inactive proliferative diabetic retinopathy were studied by immunohistochemistry.. Blood vessels expressed AGEs, TGF-beta, TNF-alpha and alpha(v)beta(3) integrin in 5, 13, 8 and 8 membranes, respectively. Stromal cells expressed AGEs, TNF-alpha and alpha(v)beta(3) integrin in 15, 13 and 3 membranes, respectively. There was no immunoreactivity for alpha(v)beta(5), alpha(5)beta(1) and alpha(2)beta(1) integrins. There were significant correlations between number of blood vessels expressing CD34 and number of blood vessels expressing AGEs (r(s) = 0.496; P = 0.043), TGF-beta (r(s) = 0.777; P < 0.001) and TNF-alpha (r(s) = 0.699; P = 0.002). There were significant correlations between number of blood vessels expressing AGEs and number of blood vessels expressing TGF-beta (r(s) = 0.532; P = 0.028) and TNF-alpha (r(s) = 0.626; P = 0.007). The correlation between number of blood vessels expressing TNF-alpha and alpha(v)beta(3) integrin was significant (r(s) = 0.617; P = 0.008). Number of blood vessels expressing CD34 (P = 0.001), TGF-beta (P = 0.006) and TNF-alpha (P = 0.002) and stromal cells expressing AGEs (P = 0.001) and TNF-alpha (P = 0.004) were significantly higher in active membranes than in inactive membranes.. Interactions of AGEs, TGF-beta, TNF-alpha and alpha(v)beta(3) integrin might be involved in pathogenesis of proliferative diabetic retinopathy fibrovascular proliferation. Topics: Antigens, CD34; Diabetic Retinopathy; Endothelium, Vascular; Epiretinal Membrane; Glycation End Products, Advanced; Humans; Immunoenzyme Techniques; Integrins; Ki-67 Antigen; Retinal Vessels; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha | 2010 |
Transient inhibition of transforming growth factor-beta1 in human diabetic CD34+ cells enhances vascular reparative functions.
Peripheral blood CD34(+) cells from diabetic patients demonstrate reduced vascular reparative function due to decreased proliferation and diminished migratory prowess, largely resulting from decreased nitric oxide (NO) bioavailability. The level of TGF-beta, a key factor that modulates stem cell quiescence, is increased in the serum of type 2 diabetic patients. We asked whether transient TGF-beta1 inhibition in CD34(+) cells would improve their reparative ability.. To inhibit TGF-beta1 protein expression, CD34(+) cells were treated ex vivo with antisense phosphorodiamidate morpholino oligomers (TGF-beta1-PMOs) and analyzed for cell surface CXCR4 expression, cell survival in the absence of added growth factors, SDF-1-induced migration, NO release, and in vivo retinal vascular reparative ability.. TGF-beta1-PMO treatment of diabetic CD34(+) cells resulted in increased expression of CXCR4, enhanced survival in the absence of growth factors, and increased migration and NO release as compared with cells treated with control PMO. Using a retinal ischemia reperfusion injury model in mice, we observed that recruitment of diabetic CD34(+) cells to injured acellular retinal capillaries was greater after TGF-beta1-PMO treatment compared with control PMO-treated cells.. Transient inhibition of TGF-beta1 may represent a promising therapeutic strategy for restoring the reparative capacity of dysfunctional diabetic CD34(+) cells. Topics: Animals; Antigens, CD34; Capillaries; Cell Survival; Diabetes Mellitus; Diabetic Angiopathies; Diabetic Retinopathy; Flow Cytometry; Hematopoietic Stem Cells; Humans; Mice; Morpholines; Morpholinos; Nitric Oxide; Receptors, CXCR4; Reperfusion Injury; Transforming Growth Factor beta; Transforming Growth Factor beta1 | 2010 |
Case of lattice corneal dystrophy due to L527R mutation in the TGFBI gene with asymmetric corneal opacity in eye laterality.
Topics: Aged; Cataract; Corneal Dystrophies, Hereditary; Corneal Opacity; Diabetic Retinopathy; Exons; Extracellular Matrix Proteins; Humans; Male; Point Mutation; Polymerase Chain Reaction; Transforming Growth Factor beta | 2010 |
The transforming growth factor-beta pathway is a common target of drugs that prevent experimental diabetic retinopathy.
Prevention of diabetic retinopathy would benefit from availability of drugs that preempt the effects of hyperglycemia on retinal vessels. We aimed to identify candidate drug targets by investigating the molecular effects of drugs that prevent retinal capillary demise in the diabetic rat.. We examined the gene expression profile of retinal vessels isolated from rats with 6 months of streptozotocin-induced diabetes and compared it with that of control rats. We then tested whether the aldose reductase inhibitor sorbinil and aspirin, which have different mechanisms of action, prevented common molecular abnormalities induced by diabetes. The Affymetrix GeneChip Rat Genome 230 2.0 array was complemented by real-time RT-PCR, immunoblotting, and immunohistochemistry.. The retinal vessels of diabetic rats showed differential expression of 20 genes of the transforming growth factor (TGF)-beta pathway, in addition to genes involved in oxidative stress, inflammation, vascular remodeling, and apoptosis. The complete loop of TGF-beta signaling, including Smad2 phosphorylation, was enhanced in the retinal vessels, but not in the neural retina. Sorbinil normalized the expression of 71% of the genes related to oxidative stress and 62% of those related to inflammation. Aspirin had minimal or no effect on these two categories. The two drugs were instead concordant in reducing the upregulation of genes of the TGF-beta pathway (55% for sorbinil and 40% for aspirin) and apoptosis (74 and 42%, respectively).. Oxidative and inflammatory stress is the distinct signature that the polyol pathway leaves on retinal vessels. TGF-beta and apoptosis are, however, the ultimate targets to prevent the capillary demise in diabetic retinopathy. Topics: Animals; Aspirin; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Gene Expression Profiling; Gene Expression Regulation; Imidazolidines; Inflammation; Oligonucleotide Array Sequence Analysis; Oxidative Stress; Rats; Receptors, Transforming Growth Factor beta; Retina; Retinal Vessels; Reverse Transcriptase Polymerase Chain Reaction; RNA; Transforming Growth Factor beta | 2009 |
[Urinary excretion of proinflammatory cytokines and transforming growth factor beta at early stages of diabetic nephropathy].
To examine correlations between urine excretion of proinflammatory cytokines, transforming growth factor beta (TGF-b) and changes in renal structure and function, quality of glycemia control in patients with type 1 diabetes mellitus.. Urinary excretion of interleukine 1-beta (IL-1b), monocytic chemoattractive protein-1 (MCP-1), RANTES and TGF-b was measured with enzyme immunoassay in 57 patients including 22 patients with normal albuminuria, 23--with microalbuminuria, 12--with macroalbuminuria. Creatinine clearance was subnormal in 8 patients with macroalbuminuria. The control group consisted of 10 healthy persons. Morphological examination of renal biopsies was performed in 8 patients with normoalbuminuria and 10 patients with microalbuminuria.. Patients with normoalbuminuria had excretion of MCP-1 significantly higher than in controls. Microalbuminuria patients showed high excretion of IL-1b, MCP-1 and TGF-b. Excretion of IL-1b, MCP-1, RANTES and TGF-b in patients with macroalbuminuria was higher than in controls and other groups of patients. Excretion of cytokines and TGFb correlated inversely with glomerular filtration rate and hemoglobin level. Positive correlations were detected between excretion of IL-1b, MCP-1, TGFb and glycated hemoglobin A(1c). In patients with normo- and microalbuminuria cytokine and TGFb excretion correlated with thickness of glomerular and glomerular basal membrane. CD68-positive macrophages were detected in the intersticium of 1 patient with normoalbuminuria and 6 patients with microalbuminuria.. Urinary excretion of proinflammatory cytokines and TGF-b was elevated in patients with DM-1 having micro- and macroalbuminuria suggesting participation of inflammation in development of diabetic nephropathy. Topics: Adolescent; Adult; Aged; Albuminuria; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Biomarkers; Chemokine CCL2; Chemokine CCL5; Diabetic Retinopathy; Female; Follow-Up Studies; Glomerular Basement Membrane; Glomerular Filtration Rate; Humans; Inflammation; Interleukin-1beta; Macrophages; Male; Middle Aged; Prognosis; Severity of Illness Index; Transforming Growth Factor beta | 2008 |
Vitreous and aqueous concentrations of proangiogenic, antiangiogenic factors and other cytokines in diabetic retinopathy patients with macular edema: Implications for structural differences in macular profiles.
The aim of the study was to determine anatomical and growth factor profiles in patients with clinically significant macular oedema (CSMO) undergoing pars plana vitrectomy (PPV). Twenty patients with moderate nonproliferative diabetic retinopathy (NPDR) with persistent CSMO underwent PPV. Patients had baseline and postoperative clinical assessment including Ocular Coherence Tomography (OCT). Baseline vitreous and aqueous and serial postoperative aqueous samples were analysed for vascular endothelial growth factor-A (VEGF-A), pigment epithelium derived Factor (PEDF) and other factors (pg/ml) including hepatocyte growth factor, MMP 9, soluble flt-1 Receptor, and TGF beta1 by ELISA. Vitreous from patients with full thickness macular holes (8) and proliferative diabetic retinopathy (22) were collected for comparison as controls. Vitreous VEGF-A concentration in the NPDR group was 957 pg/ml compared to 239 pg/ml in the macula hole (FTMH) control (p < 0.0001) and 596 pg/ml compared to PDR (p = 0.006). The median diabetic vitreous PEDF concentration was 1.36 microg/ml (FTMH 2.6 microg/ml p = 0.05). In NPDR, it was higher (1.59 microg/ml) than PDR (1.27 microg/ml) p = 0.02. There were changes to the HGF, soluble flt-1 Receptor and TGF b1 concentrations in the NPDR compared to either PDR or the normal state. In CSMO, two OCT profiles were identified: dome-shaped macular elevation (Group 1) (n = 4) and diffuse-low elevation profile (Group 2) (n = 16) which also showed differences in the postoperative median aqueous VEGF concentrations despite macular volume decreasing for both. The results suggest that there is an up-regulation of VEGF in the vitreous of the diabetic eye with a reciprocal decrease in PEDF. The structural and molecular differences between the two OCT macular profiles may explain the varying response to PPV in patients with diffuse CSMO. Topics: Aged; Angiogenesis Inducing Agents; Angiogenesis Inhibitors; Aqueous Humor; Cytokines; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Eye Proteins; Female; Hepatocyte Growth Factor; Humans; Macular Edema; Male; Middle Aged; Nerve Growth Factors; Postoperative Period; Serpins; Tomography, Optical Coherence; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1; Vitrectomy; Vitreous Body | 2006 |
Transforming growth factor-beta levels in human aqueous humor of glaucomatous, diabetic and uveitic eyes.
Transforming growth factor-beta2 is known to be present at elevated levels in the aqueous humor of patients with primary open angle glaucoma (POAG) and diabetes but not in uveitis-related secondary glaucoma. We investigated total TGF-beta2 levels and levels of the active form of TGF-beta2 in the aqueous humor of eyes with different types of glaucoma.. The concentration of the total and active form of TGF-beta2 was measured in 63 patients with primary open angle glaucoma, neovascular glaucoma complicated with diabetes (NVG), and secondary open angle glaucoma complicated with uveitis (SOAG) using a double antibody 'sandwich-indirect' ELISA method.. The levels of total TGF-beta2 in the aqueous samples of POAG, NVG, and SOAG were elevated. The levels of active TGF-beta2 in the aqueous samples of POAG, and NVG were also elevated, whereas the level of active TGF-beta2 was within the normal range in the aqueous samples of SOAG.. These results suggest that the level of TGF-beta2 may play a role in the pathology of various types of glaucoma. Topics: Adult; Aged; Aged, 80 and over; Aqueous Humor; Biomarkers; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Glaucoma, Angle-Closure; Glaucoma, Open-Angle; Humans; Middle Aged; Severity of Illness Index; Transforming Growth Factor beta; Uveitis | 2006 |
Glucose-induced serum- and glucocorticoid-regulated kinase activation in oncofetal fibronectin expression.
Preferential expression of oncofetal extra domain-B fibronectin (EDB(+) FN), a proposed angiogenic marker, has been shown in proliferative diabetic retinopathy. High levels of glucose also increase EDB(+) FN expression in endothelial cells (ECs) via transforming growth factor-beta1 (TGF-beta1) and endothelin-1 (ET-1). The present study was aimed at elucidating the role of serum- and glucocorticoid-regulated kinase (SGK-1) in glucose-induced EDB(+) FN expression. Using human macro- and microvascular ECs, we show that high levels of glucose, TGF-beta1, and ET-1 increase the EDB(+) FN expression via SGK-1 alteration at the mRNA, protein, and activity levels. Inhibition of TGF-beta1 and ET-1 prevented glucose-induced SGK-1 activation and the EDB(+) FN expression. Furthermore, using siRNA-mediated SGK-1 gene silencing, we show that glucose-induced EDB(+) FN expression can be completely prevented. These findings provide first evidence of glucose-induced SGK-1 activation in altered EDB(+) FN expression and provide novel avenues for therapeutic modalities. Topics: Blotting, Western; Cells, Cultured; Diabetic Retinopathy; Endothelin-1; Endothelium, Vascular; Enzyme Activation; Fibronectins; Gene Silencing; Glucose; Humans; Immediate-Early Proteins; Immunoblotting; Microcirculation; Microscopy, Fluorescence; Nuclear Proteins; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1; Umbilical Veins | 2005 |
Immunohistologic study of interleukin-1, transforming growth factor-beta, and alpha-smooth muscle actin in lens epithelial cells in diabetic eyes.
To assess the effects of the cytokines interleukin-1 (IL-1), transforming growth factor-beta (TGF-beta), and alpha-smooth muscle actin (alpha-SMA) in lens epithelial cells (LECs) in normal and diabetic eyes.. Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.. Ten eyes of 10 patients with diabetic mellitus and 20 normal eyes of 20 patients with senile cataract were studied. The anterior lens capsules with LECs obtained by capsulotomy during cataract surgery were cultured. The LECs obtained immediately after surgery and on the third day of culture were immunohistologically studied to assess the activities of the cytokines.. Interleukin-1 and TGF-beta staining showed a low level activity in some LECs in diabetic eyes but only a minimum level of activity in those in normal eyes. During culture, LECs in diabetic eyes became small and transformed into fusiform and fibroblast-like cells, and these cells were strongly stained for IL-1 and TGF-beta. Normal eyes showed little changes in cell morphology and were weakly stained for IL-1 and TGF-beta. Both with culture and with no culture, alpha-SMA showed only minimal activity in both diabetic and normal eyes, with no difference.. Lens epithelial cells after cataract surgery had low IL-1 and TGF-beta activities, and these activities increased during culture. Diabetic eyes showed higher cytokine activities and more marked morphologic changes than normal eyes, suggesting that increased proliferative activity and increased cytokine activity of LECs contribute to strong anterior capsule contraction in diabetic eyes. Topics: Actins; Aged; Cataract Extraction; Cell Culture Techniques; Diabetes Mellitus; Diabetic Retinopathy; Epithelial Cells; Humans; Immunoenzyme Techniques; Interleukin-1; Lens, Crystalline; Transforming Growth Factor beta | 2005 |
Oncofetal fibronectin in diabetic retinopathy.
Imbalance between extracellular matrix protein synthesis and degradation is a key feature of diabetic retinopathy. Fibronectin, a predominant constituent of the extracellular matrix, has been shown to undergo alternative splicing to produce embryonic isoforms in various pathologic conditions, such as fibrotic diseases and tumorigenesis. Two such isoforms, oncofetal fibronectin variants that are characterized by the inclusion of the oncofetal domains A and B, were the focus of the present study.. The expression of oncofetal fibronectin variants was determined in human vitreous samples obtained from patients undergoing vitrectomy for proliferative diabetic retinopathy and nondiabetes-associated ocular conditions such as macular hole. In addition, an animal model of chronic diabetes and cultured endothelial cells was used to elucidate the mechanistic basis for this aberrant expression of oncofetal fibronectin.. Expression of fibronectin containing the oncofetal domain B was upregulated in the vitreous of patients with diabetic retinopathy.. Use of a well-established animal model of chronic diabetic complications and cultured endothelial cells showed that diabetes-induced upregulation of oncofetal fibronectin is, in part, dependent on hyperglycemia-induced transforming growth factor-beta1 and endothelin-1. Furthermore, the data suggest that oncofetal fibronectin is involved in endothelial cell proliferation. Topics: Aged; Animals; Blotting, Western; Bosentan; Cell Division; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Endothelin-1; Endothelium, Vascular; Female; Fibronectins; Gene Silencing; Humans; Male; Middle Aged; Rats; Rats, Sprague-Dawley; Retinal Perforations; Reverse Transcriptase Polymerase Chain Reaction; Sulfonamides; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation; Vitrectomy; Vitreous Body | 2004 |
Association of transforming growth factor-beta (TGF-beta) T869C (Leu 10Pro) gene polymorphisms with type 2 diabetic nephropathy in Chinese.
Transforming growth factor-beta (TGF-beta) is known to play a pivotal role in the regulation of extracellular matrix (ECM) accumulation. Since diabetic nephropathy (DMN) is characterized by basement membrane thickening and mesangial expansion, control of ECM deposition is believed to be important in the pathogenesis of the disease. Recently, TGF-beta T869C (Leu 10Pro) gene polymorphism has been identified which may be associated with circulating TGF-beta levels.. In order to examine the relationship between TGF-beta gene polymorphism with DMN in Chinese, we carried out a case-control study, which recruited 123 Chinese type 2 diabetic patients with an average duration of diabetes for 12 years. A total of 58 patients who developed DMN (micro- or macroalbuminuria, with or without renal impairment) were compared with 65 diabetic patients without DMN despite similar duration of disease (normoalbuminuric and creatinine <120 micromol/L). TGF-beta T869C (Leu 10Pro) gene polymorphism was determined by polymerase chain reaction (PCR).. Both groups of patients had similar baseline characteristics, including blood pressure, diabetic control, and duration of diabetes. Distribution of TGF-beta T869C (Leu 10Pro) genotype among the whole group is confined to Hardy Weinberg equilibrium. The DMN+ group has higher frequency of TGF-beta CC/CT genotypes than the DMN- group [CC, CT, TT = (DMN+) 46, 45, 9 (%) vs. (DMN-) 37, 37, 26 (%), P < 0.05]. C allele frequency is also higher in the DMN+ group than DMN- group (69% vs. 55%, P < 0.05). The adjusted odds ratio for TGF-beta CC/CT vs. TT genotype to develop DMN is 3.8 (3.2 to 4.4). Multivariate logistic regression analysis [hypertension, gender, age, duration of diabetes, hemoglobin (HbA1c), usage of angiotensin-converting enzyme (ACE) inhibitor, and cholesterol level] showed that TGF-beta genotype (P = 0.03) is an independent predictor for type 2 DMN. Among patients with DMN, those with TGF-beta CC/CT genotypes also had worse renal function and increased risk for macroalbuminuria.. Our results suggest that TGF-beta T869C (Leu 10Pro) gene polymorphism is associated with DMN in Chinese. Topics: Aged; Aged, 80 and over; Asian People; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; Female; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Point Mutation; Polymorphism, Genetic; Predictive Value of Tests; Severity of Illness Index; Transforming Growth Factor beta | 2003 |
Vitreous polyamines spermidine, putrescine, and spermine in human proliferative disorders of the retina.
Many cytokines are involved in the pathogenesis of retinal proliferative diseases, but none has been shown to be related to a specific disorder. The aim of this study was to provide a selective marker of diabetes induced proliferative retinopathies.. 10 vitreous samples from 10 subjects affected by quiescent proliferative diabetic retinopathy (PDR), 20 vitreous samples from 20 subjects affected by active PDR, and 15 samples from 15 patients with proliferative vitreoretinopathy (PVR) were studied. Samples from 18 patients with a macular hole (n = 8) or pucker (n = 10) served as controls. Vitreous samples were obtained via pars plana vitrectomy. The polyamines spermidine, putrescine, and spermine, vascular endothelial growth factor (VEGF), interleukin 8 (IL-8), and transforming growth factor 1beta (TGF-1beta) were measured by high performance liquid chromatography (HPLC) and enzyme linked immunosorbent assay (ELISA), and the correlation coefficients between the vitreous polyamine content and VEGF, IL-8, and TGF-1beta levels were determined.. Spermidine and putrescine were expressed in normal vitreous, but spermine was not detectable. In all the test groups spermidine was 3-4 times higher than in control vitreous and putrescine was similarly lower. The spermine content was up to 15 times higher only in vitreous from patients affected by PDR. Correlation coefficients showed that the spermidine and putrescine level variations correlated with the VEGF and IL-8 content in the active PDR and PVR groups, but not in those with quiescent PDR patients, while spermine was correlated to these cytokines in PDR, but not in PVR groups.. These data suggest a significant role for spermidine and putrescine as markers of proliferative diseases of the retina. The increase in spermine, restricted to diabetic states, may indicate that this polyamine is a unique and specific index of PDR. Topics: Adult; Aged; Biomarkers; Chromatography, High Pressure Liquid; Diabetic Retinopathy; Endothelial Growth Factors; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Lymphokines; Middle Aged; Putrescine; Spermidine; Spermine; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; Vitreous Body | 2003 |
Effects of tenascin-C on normal and diabetic retinal endothelial cells in culture.
Tenascin-C (TN-C) is expressed in embryogenesis, tissue remodeling, and healing. It is up-regulated in retinas of patients affected by diabetic retinopathy (DR). Because TN-C may promote neovascularization, its potential angiogenic effects were examined in vitro in normal and diabetic retinal endothelial cells (RECs).. Bovine and human RECs were cultured on plastic or reconstituted basement membrane (BM) matrix. Production of TN-C, capillary-like tube formation, secondary sprouting, and cell migration, survival, and proliferation were measured with or without angiogenic growth factors (GFs). Antibodies and inhibitors were used to determine the involvement of specific TN-C receptors and signaling pathways.. TN-C significantly delayed collapse of REC capillary-like tubes on BM matrix. It decreased tube involution associated with serum deprivation, high glucose, and exposure to TGF-beta. TN-C's enhancement of tube stability was mediated by alphavbeta3 integrin. TN-C increased REC viability in 0.5% serum and stimulated REC proliferation in 10% serum. It promoted REC secondary sprouting on BM matrix, which involved signaling through mitogen-activated kinase kinase (MEK) and p38 mitogen-activated protein kinase. TN-C also enhanced tube branching after treatment with VEGF and stimulated REC migration twofold. Angiogenic GF increased TN-C production by RECs in an additive manner, which may explain higher levels of TN-C deposition in DR cells.. TN-C was overexpressed in diabetic and DR REC cultures. TN-C enhanced the sprouting, migratory, and survival effects of angiogenic GFs, and had distinct proliferative, migratory, and protective capacities. The data suggest that TN-C may act as a proangiogenic mediator in DR and other pathologic conditions involving neovascularization. Topics: Adolescent; Aged; Angiogenesis Inducing Agents; Animals; Basement Membrane; Blotting, Western; Cattle; Cell Division; Cell Movement; Cell Survival; Cells, Cultured; Diabetic Retinopathy; Endothelial Growth Factors; Endothelium, Vascular; Female; Humans; Lymphokines; Male; Middle Aged; Receptors, Antigen; Retinal Neovascularization; Retinal Vessels; Signal Transduction; Tenascin; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; Wound Healing | 2002 |
Polymorphism R25P in the gene encoding transforming growth factor-beta (TGF-beta1) is a newly identified risk factor for proliferative diabetic retinopathy.
Associations of the genetic polymorphisms in the promoter region and the signal peptide sequence of the transforming growth factor-beta (TGF-beta1) gene with proliferative diabetic retinopathy (PDR) in patients with non-insulin-dependent diabetes mellitus (NIDDM) were studied. A total of 245 Caucasian subjects comprised the two groups: NIDDM patients with PDR (n = 73) and NIDDM patients without PDR (n = 172). Allele frequencies of common TGF-beta1 polymorphisms (at positions -988C/A, -800G/A, -509C/T, +869T/C (L10P), and +915G/C (R25P)) were determined by PCR-based methodology. All polymorphisms were in strong linkage disequilibrium (P < 10(-2)). Significantly higher frequencies of both the L allele and the R allele of the signal sequence polymorphisms in PDR subjects were found (after a correction for multiple comparisons, P(corr) < 10(-2) and P(corr) < 10(-4), respectively). Calculated odds ratios (ORs) for the LL and RR genotypes were 2.89 (95% confidence interval (CI), 1.6-5.1) and 19.73 (95% CI, 2.6-146.8), respectively. No significant differences between groups were found for the -800G/A and -509C/T polymorphisms. The -988A allele was not represented in our sample. Multiple logistic regression identified age, diabetes duration, and R25P polymorphism as significant predictors (P = 0.002, P = 0.000003, and P = 0.007, respectively). The frequencies of genotype combinations of the -800G/A, -509C/T, L10P, and R25P TGF-beta(1) polymorphisms were significantly different between the PDR and non-PDR groups (chi(2) = 37.83, df = 20, P < 10(-2)). The frequency of haplotype consisting of majority alleles was found significantly associated with PDR (P < 0.03). The presented data indicate that the R25P polymorphisms in the TGF-beta1 gene could be regarded as a strong genetic risk factor for PDR. Topics: Aged; Alleles; Amino Acid Substitution; Diabetes Mellitus, Type 2; Diabetic Retinopathy; DNA; DNA Mutational Analysis; Female; Gene Frequency; Genotype; Haplotypes; Humans; Infant, Newborn; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Single-Stranded Conformational; Risk Factors; Transforming Growth Factor beta | 2002 |
Changes in vitreous concentrations of human hepatocyte growth factor (hHGF) in proliferative diabetic retinopathy: implications for intraocular hHGF production.
We measured human hepatocyte growth factor (hHGF) concentrations in the original vitreous and in the artificial vitreous after vitrectomy in 13 patients with proliferative diabetic retinopathy (PDR) undergoing repeated pars plana vitrectomy, in order to investigate whether the vitreous hHGF concentration is related to the recurrence of PDR after vitrectomy as well as to the original occurrence of PDR. We also examined the relationship between vitreous concentrations of hHGF and transforming growth factor-beta(2) (TGF-beta(2)), the predominant TGF-beta isoform in the vitreous, in 14 patients with PDR. For the original vitreous, mean hHGF concentrations were higher (P<0.05) in that from patients with severe PDR (vitreous haemorrhage, fibrovascular proliferation and tractional retinal detachment) than in that from patients with vitreous haemorrhage alone. In the artificial vitreous, mean vitreous hHGF concentrations were higher (P<0.05) in that from patients with severe PDR than in that from patients with vitreous haemorrhage alone or with vitreous haemorrhage plus fibrovascular proliferation. No correlation was found between the hHGF concentration in the artificial vitreous and time between vitrectomies. Vitreous hHGF concentrations were directly proportional to vitreous concentrations of latent TGF-beta(2) (r=0. 831; P=0.0002), but inversely proportional to vitreous concentrations of active TGF-beta(2) (r=0.495; P=0.072), which inhibits hHGF production. A decreased conversion of latent into active TGF-beta(2) in ocular disorders such as PDR is likely to result in an increased concentration of hHGF in the vitreous. Thus intraocular hHGF may be involved in pathological mechanisms causing not only the occurrence, but also the recurrence, of PDR. Topics: Adult; Aged; Diabetic Retinopathy; Female; Hepatocyte Growth Factor; Humans; Male; Middle Aged; Recurrence; Transforming Growth Factor beta; Vitrectomy; Vitreous Body; Vitreous Hemorrhage | 2000 |
TGF-beta1, TGF-beta receptor II and ED-A fibronectin expression in myofibroblast of vitreoretinopathy.
Formation of scarlike epiretinal membranes (ERMs) constitutes potentially the end stage of evolution of proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Among various cellular populations, ERMs contain cells with contractile features typical of myofibroblasts. The current study was conducted to investigate the presence of transforming growth factor (TGF)-beta1, TGF-beta receptor II (RII) and ED-A fibronectin (FN), the main inducers of myofibroblastic differentiation in ERMs in PDR and PVR.. Samples of ERM were obtained from 23 patients during microsurgery for PVR or PDR. Electron microscopy, immunohistochemistry, and confocal microscopy with antibodies recognizing beta-smooth muscle (SM) actin, desmin, TGF-beta1, TGF-beta receptors I and II, and ED-A FN were performed.. alpha-SM actin was detected in all ERMs, whereas desmin was present in 50% of the cases. ED-A FN was expressed in all ERMs in close relation with alpha-SM actin-positive myofibroblasts. In addition, TGF-beta1 and TGF-beta R II were always present, TGF-beta RII being expressed in both alpha-SM actin-positive and negative fibroblastic cells.. Myofibroblast accumulation is a key event in ERM-associated traction retinal detachment occurring during PVR and PDR. The current results suggest that the presence of alpha-SM actin-positive myofibroblasts is probably dependent on the concomitant neoexpression of TGF-beta1, TGF-beta RII, and ED-A FN. The results furnish new data on the mechanism of alpha-SM actin stimulation in fibroblasts in a human pathologic setting. Topics: Actins; Adolescent; Adult; Aged; Aged, 80 and over; Diabetic Retinopathy; Epiretinal Membrane; Female; Fibroblasts; Fibronectins; Fluorescent Antibody Technique, Indirect; Humans; Immunoenzyme Techniques; Male; Microscopy, Confocal; Middle Aged; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Vitreoretinopathy, Proliferative | 2000 |
Retinal expression, regulation, and functional bioactivity of prostacyclin-stimulating factor.
Prostacyclin-stimulating factor (PSF) acts on vascular endothelial cells to stimulate the synthesis of the vasodilatory molecule prostacyclin (PGI2). We have examined the expression, regulation, and hemodynamic bioactivity of PSF both in whole retina and in cultured cells derived from this tissue. PSF was expressed in all retinal cell types examined in vitro, but immunohistochemical analysis revealed PSF mainly associated with retinal vessels. PSF expression was constitutive in retinal pericytes (RPCs) but could be modulated in bovine retinal capillary endothelial cells (RECs) by cell confluency, hypoxia, serum starvation, high glucose concentrations, or inversely by soluble factors present in early vs. late retinopathy, such as TGF-beta, VEGF, or bFGF. In addition, RPC-conditioned media dramatically increased REC PGI2 production, a response inhibited by blocking PSF with a specific antisense oligodeoxynucleotide (ODN). In vivo, PGI2 increased retinal blood flow (RBF) in control and diabetic animals. Furthermore, the early drop in RBF during the initial weeks after inducing diabetes in rats, as well as the later increase in RBF, both correlated with levels of retinal PSF. RBF also responded to treatment with RPC-conditioned media, and this effect could be partially blocked using the antisense PSF ODN. We conclude that PSF expressed by ocular cells can induce PGI2, retinal vascular dilation, and increased retinal blood flow, and that alterations in retinal PSF expression may explain the biphasic changes in RBF observed in diabetes. Topics: Animals; Base Sequence; Cattle; Cells, Cultured; Diabetic Retinopathy; DNA Primers; Endothelium, Vascular; Epoprostenol; Hemodynamics; Mice; Neovascularization, Pathologic; Rats; Retina; Retinal Vessels; RNA, Messenger; Transforming Growth Factor beta | 2000 |
Deficient activation and different expression of transforming growth factor-beta isoforms in active proliferative diabetic retinopathy and neovascular eye disease.
An increased expression and secretion of angiogenic growth factors was proposed to occur in proliferative diabetic retinopathy and other neovascularizing retinal diseases. However, a loss of anti-angiogenic factors also might promote retinal neovascularization. Therefore we investigated the active and latent vitreous levels of the subtypes of the endothelial anti-mitogen transforming growth factor-beta in vitreous of 58 patients. Four groups of patients were compared: Controls without retinal hypoxia, patients with quiescent and active proliferative diabetic retinopathy (PDR), and patients with severe retinal hypoxia resulting in rubeosis iridis. Whereas the amount of total TGF-beta in the four groups did not differ significantly, latent TGF-beta isoform expression showed complex alterations in ocular vitreous. Levels of active TGF-beta of patients with active PDR (79.5 +/- 28 pg/ml; n = 8) were decreased to 20% of the control levels (378 +/- 55 pg/ml; n = 12; p = 0.0005) and 25% of the mean concentration in quiescent PDR (346 +/- 64 pg/ml; n = 9; p = 0.0021). Levels in rubeosis (52 +/- 10 pg/ml; n = 10) did not differ significantly from those found in active PDR but were decreased to 15% of those in patients with quiescent PDR (p = 0.0004). Furthermore a highly significant inverse correlation between active TGF-beta and alpha2-antiplasmin, a liver produced inhibitor of the activation of TGF-beta by plasmin was noted (r = -0.59; n = 28; p = 0.001). We conclude that deficient activation of TGF-beta occurs in active proliferative diabetic retinopathy and in hypoxic angiogenesis most likely as a consequence of a blood retina barrier breakdown and influx of alpha2-antiplasmin from serum. The disinhibition of endothelial cell proliferation may be a central component in the process of neovascularization. Topics: Aged; alpha-Macroglobulins; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Eye; Female; Fibrinolysin; Humans; Male; Middle Aged; Neovascularization, Pathologic; Retinal Diseases; Transforming Growth Factor beta; Vitreous Body | 1999 |
Angiogenic interaction between retinal endothelial cells and pericytes from normal and diabetic rabbits, and phenotypic changes of diabetic cells.
Retinal endothelial cells (ECs) and pericytes (PCs) were cloned and cultured from normal and diabetic rabbits to clarify the mechanism of diabetic proliferative retinopathy from the viewpoint of the interaction between ECs and PCs, and phenotypic changes of diabetic cells. PC-conditioned medium (PC-CM) from normal rabbits stimulated in vitro angiogenesis of diabetic ECs more than that of normal ECs. in vitro angiogenesis was also more stimulated in diabetic ECs than in normal ECs by basic fibroblast growth factor (bFGF) or transforming growth factor-beta 1, indicating that diabetic ECs are different from normal ECs in terms of angiogenic potential. One mechanism of this property of diabetic ECs was the acceleration of cell proliferation but not of cell migration, because diabetic ECs grew more rapidly but did not migrate more than normal ECs in response to PC-CM or bFGF. Moreover, PC-CM from diabetic PCs stimulated angiogenesis of normal ECs more than that from normal PCs, indicating that diabetic PCs secreted more angiogenic factor(s) than normal PCs. The angiogenic, mitogenic and migratory activities of PC-CM both from normal and diabetic PCs were similarly inhibited by an anti-bFGF antibody. Western blot analysis revealed this factor to be a bFGF-like molecule. These data indicate that the interaction between ECs and PCs and the phenotypic changes of diabetic ECs and PCs both contribute to the proliferative retinopathy in diabetes. Topics: Animals; Blotting, Western; Cell Division; Cell Movement; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Dose-Response Relationship, Drug; Endothelium, Vascular; Fibroblast Growth Factor 2; Fluorescent Antibody Technique; Male; Neovascularization, Pathologic; Pericytes; Rabbits; Retinal Vessels; Time Factors; Transforming Growth Factor beta | 1999 |
Roles of cytokines in diabetic retinopathy.
Topics: Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Humans; Interleukin-6; Middle Aged; Transforming Growth Factor beta; Vitreous Body; Vitreous Hemorrhage | 1999 |
Basement membrane and growth factor gene expression in normal and diabetic human retinas.
Recently, we found abnormal accumulation of several extracellular matrix components in retinal basement membranes in human diabetic retinopathy (DR). Others have described increased levels of various growth factors within the vitreous of DR patients. This study examined mRNA levels of these extracellular matrix components and growth factors within human retinal tissues.. Total retinal RNA was analyzed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). RT-PCR products were identified by Southern blotting. Samples were normalized with respect to beta2-microglobulin cDNA. Twenty-one retinas were analyzed: 6 normal, 7 diabetic without DR and 8 diabetic with DR.. In diabetic retinas without DR, the expression levels of most genes were similar to normal. In DR retinas, tenascin-C mRNA expression increased compared to both normal and diabetics without DR. By RT-PCR and Northern blotting, mainly small tenascin-C mRNA isoforms were expressed, and some of them were elevated in DR retinas. Fibronectin mRNA was elevated in DR compared to normal retinas, possibly due to the overexpression of extradomain A-containing isoform (ED-A+, or cellular fibronectin). In DR retinas, gene expression of vascular endothelial growth factor and placenta growth factor was elevated compared to normal, although mRNA for these growth factors receptors (VEGFR-1/Flt-1 and VEGFR-2/KDR) did not change significantly. Transforming growth factor-beta1 mRNA also increased in DR retinas.. The data suggest that proliferative DR development may be associated with increased retinal expression of vascular endothelial growth factor, placenta growth factor and transforming growth factor-beta1 that possibly triggers the deposition of small tenascin-C isoforms in the blood vessel walls. Angiogenesis-stimulating tenascin-C may further promote diabetic retinal neovascularization. Topics: Aged; Aged, 80 and over; Basement Membrane; Diabetes Mellitus; Diabetic Retinopathy; Endothelial Growth Factors; Extracellular Matrix Proteins; Female; Fibronectins; Gene Expression; Growth Substances; Humans; Lymphokines; Male; Middle Aged; Placenta Growth Factor; Pregnancy Proteins; Reference Values; RNA, Messenger; Tenascin; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors | 1999 |
Regulation of transforming growth factor-beta, basic fibroblast growth factor, and vascular endothelial cell growth factor mRNA in peripheral blood leukocytes in patients with diabetic retinopathy.
In the present study, we examined the effect of glucose concentration on the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor-beta (TGF-beta) mRNA using reverse transcriptase-polymerase chain reaction (RT-betaCR) in normal healthy leukocytes in vitro and in leukocytes from patients with type 1 diabetes mellitus. In vitro, the level of TGF-beta mRNA was altered in response to the glucose concentration (maximum at 10 mmol/L), while bFGF mRNA remained relatively constant and VEGF mRNA varied with no clear correlation with the glucose concentration. Leukocytes from type 1 patients showed no difference in bFGF or TGF-beta mRNA levels compared with age-matched healthy controls. However, VEGF mRNA was significantly lower in type 1 patients compared with controls (P < .05). When the patients were subtyped according to the severity of retinopathy, the level of TGF-beta mRNA was elevated selectively in patients with evidence of active new retinal vessels (P < .01) and VEGF121 mRNA was reduced in patients with mild to moderate retinopathy. Thus, leukocyte growth factor mRNAs respond to acute changes in the glucose concentration in vitro, and are differentially expressed in type 1 diabetic patients during the course of the disease. Topics: Adult; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Electrophoresis, Agar Gel; Endothelial Growth Factors; Female; Fibroblast Growth Factor 2; Gene Expression Regulation; Glucose; Glycated Hemoglobin; Humans; Leukocytes; Lymphokines; Male; Middle Aged; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors | 1999 |
Transforming growth factor beta2 in the vitreous in proliferative diabetic retinopathy.
To evaluate the hypothesis that transforming growth factor beta2 (TGF-beta2) is involved in the cause of proliferative diabetic retinopathy (PDR).. We assayed TGF-beta2 levels in the vitreous of patients with PDR and other vitreoretinal disorders. Forty-nine vitreous specimens were obtained from eyes of patients with PDR undergoing vitrectomy, and 19 vitreous specimens from nondiabetic subjects served as controls. We assessed TGF-beta2 levels using an enzyme-linked immunosorbent assay. Both mature and total TGF-beta2 levels were quantified.. The mean (+/- SD) total levels of TGF-beta2 were 2634 (+/- 1652) pg/mL in the patients with PDR and 1305 (+/- 972) pg/mL in controls. The mean (+/- SD) levels of mature TGF-beta2 were 244 (+/- 316) pg/mL in patients with PDR and 79 (+/- 81) pg/mL in controls. Total and mature TGF-beta2 levels were significantly greater in patients with PDR (total TGF-beta2, P <.001; mature TGF-beta2, P <.01). Mature TGF-beta2 levels were higher in the vitreous of patients who had severe fibrous proliferation.. The results indicate increased levels of both total and mature TGF-beta2 in the vitreous of patients with PDR, suggesting that TGF-beta2 plays an important role in the pathogenesis of PDR. Topics: Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Female; Humans; Laser Coagulation; Male; Middle Aged; Transforming Growth Factor beta; Vitrectomy; Vitreous Body | 1998 |
[Myofibroblasts and retinal fibrovascular membranes].
Epiretinal tissue proliferations occurring during the evolution of ischemic microangiopathies or preretinal diseases are tough to cause retinal detachment by traction mechanisms. Cellular migration/proliferations and finally contraction are tough to be the pathogenic element. Myofibroblasts are contractile cells having features intermediate between those of the fibroblasts and smooth muscle. We conducted a study to explore whether such cells are present in preretinal membranes.. 8 membranes, preelevated during vitrectomy for proliferative vitreoretinopathy or diabetic proliferative vitreoretinopathy, were analysed with immunostaining technique searching for alpha-actine smooth muscle, desmine, which are specific markers for myofibroblasts and TGF-beta1, that is considered as the mean factor promoting the transformation of fibroblasts into myofibroblasts.. All the histological preparation showed abundant staining with antibody against alpha-actine smooth muscle, desmine and TGF-beta1.. Myofibroblasts are one of the major cellular element of preretinal membranes. They are scattered throughout the membrane and seem to account for their contractile properties. Topics: Actins; Cell Division; Cell Movement; Desmin; Diabetic Retinopathy; Epiretinal Membrane; Fibroblasts; Humans; Myosins; Retinal Detachment; Transforming Growth Factor beta; Vitreoretinopathy, Proliferative | 1998 |
Intravitreal growth factors in proliferative diabetic retinopathy: correlation with neovascular activity and glycaemic management.
Many growth factors are implicated in proliferative diabetic retinopathy (PDR). It was decided to test the hypothesis that no one factor is predominant but that a regular profile of levels of different growth factors might be operating, and that the profile might differ according to whether or not insulin therapy was part of the patient's glycaemic management. The levels of several growth factors in vitrectomy samples were therefore determined from diabetic patients with tractional, non-haemorrhagic sequelae of PDR and these levels were correlated with (a) each other (growth factor profile), (b) neovascular activity, and (c) the method of glycaemic management (insulin treated (IT) or non-insulin treated (NIT)).. 72 samples of vitreous were obtained from either diabetic patients with PDR (n = 51) or non-diabetic (control) patients (n = 21). Levels of bFGF, IGF-I, EGF, and insulin were determined by radioimmunoassay; levels of TGF-beta 2 by ELISA; and levels of IGF-I binding protein by western ligand blotting. The data were analysed using appropriate statistics.. There was no regular growth factor profile. bFGF levels were significantly greater in vitreous from NIT patients compared with IT patients and controls. The highest levels of bFGF were found in NIT patients with actively vascularised membranes. TGF-beta 2 levels were significantly greater in vitreous from IT patients compared with NIT patients and controls The highest levels of TGF-beta 2 were found in IT patients with actively vascularised membranes. IGF-I levels were significantly greater in diabetics (irrespective of insulin treatment) than non-diabetics and the highest levels of IGF-I were found in IT patients with actively vascularised membranes. A 34 kDa IGFBP was the predominant IGFBP identified in vitreous and was found to be elevated in diabetics patients.. In PDR there is a correlation between intravitreal growth factor levels and both disease state (whether active or fibrotic) and method of glycaemic management. Topics: Analysis of Variance; Case-Control Studies; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Fibroblast Growth Factor 2; Growth Substances; Humans; Hypoglycemia; Insulin; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor II; Middle Aged; Neovascularization, Pathologic; Radioimmunoassay; Transforming Growth Factor beta; Vitreous Body | 1997 |
Apoptosis in proliferative vitreoretinal disorders: possible involvement of TGF-beta-induced RPE cell apoptosis.
The targeted induction of apoptosis is a novel therapeutic approach to control the unlimited growth of proliferating cells. Since massive proliferation of cells at the vitreoretinal interface is a key feature of proliferative vitreoretinal disorders, we sought to identify apoptosis in epiretinal membranes from patients with proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR) and macular pucker. Further, we evaluated the possible induction of apoptosis of retinal pigment epithelial (RPE) cells by transforming growth factor-beta(TGF-beta). Apoptotic cells were identified by in situ DNA end labeling and acridine orange staining on paraffin-embedded tissue sections from epiretinal membranes of patients with all vitreoretinal disorders examined. Labeled nuclei or condensed chromatin were scattered throughout the membranes or occurred in clusters. Most apoptotic cells were RPE-derived, as assessed by cytokeratin immunochemistry. No apoptotic glial cells were detected. In PVR, proliferative activity, as confirmed by Ki-67 immunochemistry, was associated with short history and rapid disease progression. Apoptotic nuclei were observed more frequently in long-standing PVR or slow progression towards traction retinal detachment. TGF-beta was detected in all control vitreous samples by bioassay at concentrations below 20 ng ml-1. TGF-beta levels increased up to 20-fold in pathological vitreous. Marked heterogeneity was observed in all patient groups. The degree of TGF-beta activation was significantly higher in PVR than in PDR. Proapoptotic effects of TGF-beta were demonstrated in cultured human RPE cells by electron microscopy, in situ DNA end labeling, comet assay and a photometric enzyme immunoassay for histone-associated DNA fragments. Apoptosis appears to be a key regulatory mechanism of growth control of specific cell populations in proliferative vitreoretinal disorders. Administration of proapoptotic growth factors such as TGF-beta may provide a novel approach to inhibit cellular proliferation at the vitreoretinal interface. Topics: Apoptosis; Cells, Cultured; Diabetic Retinopathy; Humans; Immunohistochemistry; Ki-67 Antigen; Pigment Epithelium of Eye; Retinal Diseases; Transforming Growth Factor beta; Vitreous Body | 1997 |
Pathophysiology of diabetic complications.
Topics: Animals; Diabetes Complications; Diabetes Mellitus; Diabetic Nephropathies; Diabetic Retinopathy; Glycation End Products, Advanced; Humans; Mice; Mice, Inbred NOD; Rats; Rats, Inbred BB; Transforming Growth Factor beta | 1997 |
Elevated plasma levels of transforming growth factor-beta 1 in NIDDM.
Transforming growth factor-beta (TGF-beta) is a potent inducer of extracellular matrix production and of fibrogenesis and has been associated with the occurrence of diabetic micro- and macrovascular complications. Our aim was to determine whether circulating levels of TGF-beta 1 are altered in NIDDM and, if so, whether they are correlated with blood glucose and show an association with diabetic complications.. Plasma levels of TGF-beta 1 were determined by enzyme-linked immunosorbent assay in 44 NIDDM patients and 28 control subjects of comparable age and weight and were correlated with parameters of metabolic control and the occurrence of micro- and macrovascular complications.. TGF-beta 1 was significantly elevated in NIDDM (7.9 +/- 1.0 ng/ml), as compared with control subjects (3.1 +/- 0.4 ng/ml, P < 0.001) and correlated with glycosylated hemoglobin (r2 = 0.42; P < 0.001). Thrombocyte levels of TGF-beta 1 were similar in control subjects (54 +/- 7 pg/ml, n = 16) and diabetic patients (61.6 +/- 18 pg/ml, n = 13; P = 0.357). Elevated TGF-beta 1 levels were associated with retinopathy and neuropathy.. We conclude that plasma levels of TGF-beta 1 are elevated in NIDDM patients and may be related to average blood glucose. Preliminary data suggest that they may contribute to the occurrence of diabetic complications. Topics: Aged; Biomarkers; Blood Glucose; Coronary Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Female; Glycated Hemoglobin; Humans; Hypertension; Male; Middle Aged; Reference Values; Regression Analysis; Statistics, Nonparametric; Transforming Growth Factor beta | 1996 |