transforming-growth-factor-beta and Diabetes-Mellitus--Type-2

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

Follistatin (FST) is a glycoprotein which main role is antagonizing activity of transforming growth factor β superfamily members. Folistatin-related proteins such as follistatin-like 3 (FSTL3) also reveal these properties. The exact function of them has still not been established, but it can be bound to the pathogenesis of metabolic disorders. So far, there were performed a few studies about their role in type 2 diabetes, obesity or gestational diabetes and even less in type 1 diabetes. The outcomes are contradictory and do not allow to draw exact conclusions. In this article we summarize the available information about connections between follistatin, as well as follistatin-like 3, and metabolic disorders. We also emphasize the strong need of performing further research to explain their exact role, especially in the pathogenesis of diabetes and obesity.

Topics: Diabetes Mellitus, Type 2; Follistatin; Humans; Obesity; Transforming Growth Factor beta

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

Islet dysfunction is a hallmark of type 2 diabetes mellitus (T2DM). Compelling evidence suggests that accumulation of islet amyloid in the islets of Langerhans significantly contribute to β-cell dysfunction and diabetes. Emerging evidence implicates a role for cystic fibrosis transmembrane-conductance regulator in the regulation of insulin secretion from pancreatic islets. Impaired first-phase insulin responses and glucose homeostasis have also been reported in cystic fibrosis patients. The transforming growth factor-β protein superfamily is central regulators of pancreatic cell function, and has a key role in pancreas development and pancreatic disease, including diabetes and islet dysfunction. It is also becoming clear that islet inflammation plays a key role in the development of islet dysfunction. Inflammatory changes, including accumulation of macrophages, have been documented in type 2 diabetic islets. Islet dysfunction leads to hyperglycemia and ultimately the development of diabetes. In this review, we describe these risk factors and their associations with islet dysfunction.

Topics: Amyloid; Animals; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Diabetes Mellitus, Type 2; Disease Progression; Glucose; Homeostasis; Humans; Hyperglycemia; Inflammation; Insulin; Insulin Secretion; Islets of Langerhans; Macrophages; Pancreas; Risk Factors; Transforming Growth Factor beta

Cardiovascular diseases account for the major cause of morbidity and mortality among individuals with diabetes. The diabetic cardiomyopathy (DCM) is a type of diabetic cardiovascular disease, which further directs to the heart failure. The researchers found that diabetes induced cardiac fibrosis plays a vital role in several of the pathological changes that associated with DCM, causing left ventricular hypertrophy (LVH), diastolic dysfunction and systolic dysfunction. However, the mechanisms involved in the pathogenesis of DCM are still elusive. Many studies have demonstrated that the transforming growth factor beta (TGF-β) is one of the molecular mediators implicated in the progression of fibrogenesis. In diabetes, hyperglycemia causes the expression changes of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), TGF-β genes, TGF-β proteins and their receptors. Activated TGF-β further leads to cardiac fibrosis, which in turn inducing DCM through the SMAD-dependent and independent pathways. Here, we reviewed the the molecular pathways that activate TGF-β then leading to cardiac fibrosis, which induced the pathological changes of DCM. Illustrating the pathways of TGF-ß would propose an efficient way for the management of diabetic cardiomyopathy (see Fig. 1).

Topics: Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Fibrosis; Heart Failure; Humans; Myocardium; Signal Transduction; Transforming Growth Factor beta

AGE/RAGE signaling has been a well-studied cascade in many different disease states, particularly diabetes. Due to the complex nature of the receptor and multiple intersecting pathways, the AGE/RAGE signaling mechanism is still not well understood. The purpose of this review is to highlight key areas of AGE/RAGE mediated vascular calcification as a complication of diabetes. AGE/RAGE signaling heavily influences both cellular and systemic responses to increase bone matrix proteins through PKC, p38 MAPK, fetuin-A, TGF-β, NFκB, and ERK1/2 signaling pathways in both hyperglycemic and calcification conditions. AGE/RAGE signaling has been shown to increase oxidative stress to promote diabetes-mediated vascular calcification through activation of Nox-1 and decreased expression of SOD-1. AGE/RAGE signaling in diabetes-mediated vascular calcification was also attributed to increased oxidative stress resulting in the phenotypic switch of VSMCs to osteoblast-like cells in AGEs-induced calcification. Researchers found that pharmacological agents and certain antioxidants decreased the level of calcium deposition in AGEs-induced diabetes-mediated vascular calcification. By understanding the role the AGE/RAGE signaling cascade plays diabetes-mediated vascular calcification will allow for pharmacological intervention to decrease the severity of this diabetic complication.

Topics: alpha-2-HS-Glycoprotein; Diabetes Mellitus, Type 2; Glycation End Products, Advanced; Humans; MAP Kinase Signaling System; NADPH Oxidase 1; NADPH Oxidases; NF-kappa B; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Protein Kinase C; Receptor for Advanced Glycation End Products; Signal Transduction; Superoxide Dismutase-1; Transforming Growth Factor beta; Vascular Calcification

Topics: Cytokines; Diabetes Mellitus, Type 2; Humans; Interleukin-10; Interleukin-17; Interleukin-6; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Chronic kidney disease (CKD) is becoming a worldwide epidemic, driven largely by the dramatic rise in the prevalence of diabetes and obesity. Novel targets and treatments for CKD are, therefore, desperately needed-to both mitigate the burden of this disease in the general population and reduce the necessity for renal replacement therapy in individual patients. This Review highlights new insights into the mechanisms that contribute to CKD, and approaches that might facilitate the development of disease-arresting therapies for CKD. Particular focus is given to therapeutic approaches using antifibrotic agents that target the transforming growth factor β superfamily. In addition, we discuss new insights regarding the roles of vascular calcification, the NADPH oxidase family, and inflammation in the pathogenesis of CKD. We also highlight a new understanding regarding kidney energy sensing pathways (AMPK, sirtuins, and mTOR) in a variety of kidney diseases and how they are linked to inflammation and fibrosis. Finally, exciting new insights have been made into the role of mitochondrial function and mitochondrial biogenesis in relation to progressive kidney disease. Prospective therapeutics based on these findings will hopefully renew hope for clinicians and patients in the near future.

Topics: AMP-Activated Protein Kinases; Animals; Anti-Inflammatory Agents; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Progression; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fibrosis; Glucuronidase; Humans; Klotho Proteins; Mitochondria; Models, Animal; NADPH Oxidases; NF-kappa B; Renal Insufficiency, Chronic; Transforming Growth Factor beta; Vascular Calcification

Podocyte loss is a common feature in human diabetes as well as in experimental diabetes in rodents. Almost all components of the diabetic milieu lead to serious podocyte stress, driving the cells towards cell cycle arrest and hypertrophy, detachment and apoptosis. Common pathway components induced by high glucose and advanced glycation end-products are reactive oxygen species, cyclin-dependent kinases (p27(Kip1)) and transforming growth factor-beta. In addition, mechanical stresses by stretch or shear forces, insulin deficiency or insulin resistance are independent components resulting in podocyte apoptosis and detachment. In this review, we discuss the common pathways leading to podocyte death as well as novel pathways and concepts of podocyte dedifferentiation and detachment that influence the progression of diabetic glomerulopathy.

Topics: Actins; Apoptosis; Chemokines; Cyclin-Dependent Kinase Inhibitor p27; Cytokines; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucose; Glycation End Products, Advanced; Humans; Hyperglycemia; Insulin; Insulin Resistance; Podocytes; Stress, Mechanical; Transforming Growth Factor beta

The thiazolidinediones are agonists for peroxisome proliferator-activated receptor-gamma, and promote insulin sensitization and improve dyslipidemia in patients with type II diabetes mellitus. Peroxisome proliferator-activated receptor-gamma transduces its actions by binding to common consensus response elements called peroxisome proliferator-activated receptor-response elements, thus modifying expression of numerous genes. Peroxisome proliferator-activated receptor-gamma is widely expressed, including in macrophages and vascular smooth muscle cells. I will review recent novel insights into peroxisome proliferator-activated receptor-gamma agonist actions.. The thiazolidinediones have beneficial effects in humans with type II diabetes related in part to improvement of dysmetabolic syndrome, and also have beneficial effects on progressive renal damage in animal models of diabetic nephropathy and in models with severe hyperlipidemia. Peroxisome proliferator-activated receptor-gamma agonists also have direct benefits on progressive renal injury independent of altering the dysmetabolic profile.. We will review selected evidence of actions of peroxisome proliferator-activated receptor-gamma agonists beyond metabolism, focusing on experimental work, and examine interactions with other key profibrotic mediators, including transforming growth factor-beta and the renin-angiotensin system.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Disease Progression; Humans; Hypoglycemic Agents; PPAR gamma; Renal Insufficiency, Chronic; Renin-Angiotensin System; Thiazolidinediones; Transforming Growth Factor beta

Alzheimer disease (AD) and type 2 diabetes mellitus (T2DM) are conditions that affect a large number of people in the industrialized countries. Both conditions are on the increase, and finding novel treatments to cure or prevent them are a major aim in research. Somewhat surprisingly, AD and T2DM share several molecular processes that underlie the respective degenerative developments. This review describes and discusses several of these shared biochemical and physiological pathways. Disturbances in insulin signalling appears to be the main common impairment that affects cell growth and differentiation, cellular repair mechanisms, energy metabolism, and glucose utilization. Insulin not only regulates blood sugar levels but also acts as a growth factor on all cells including neurons in the CNS. Impairment of insulin signalling therefore not only affects blood glucose levels but also causes numerous degenerative processes. Other growth factor signalling systems such as insulin growth factors (IGFs) and transforming growth factors (TGFs) also are affected in both conditions. Also, the misfolding of proteins plays an important role in both diseases, as does the aggregation of amyloid peptides and of hyperphosphorylated proteins. Furthermore, more general physiological processes such as angiopathic and cytotoxic developments, the induction of apoptosis, or of non-apoptotic cell death via production of free radicals greatly influence the progression of AD and T2DM. The increase of detailed knowledge of these common physiological processes open up the opportunities for treatments that can prevent or reduce the onset of AD as well as T2DM.

Topics: Alzheimer Disease; Amyloid; Animals; Diabetes Mellitus, Type 2; Glycation End Products, Advanced; Humans; Insulin; Neurofibrillary Tangles; tau Proteins; Transforming Growth Factor beta

Actual strategies to delay progression of diabetic nephropathy provide imperfect protection when started late in the course of the disease. Ohtomo et al. now demonstrate that thiazolidinedione treatment was associated with a remarkable improvement in proteinuria and renal function, offering a new potential treatment for diabetic nephropathy.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Renin-Angiotensin System; Thiazolidinediones; Transforming Growth Factor beta

Diabetic nephropathy characterized by proteinuria and sclerosis is the leading cause of renal failure, but its mechanisms are not well understood. Zucker Obese (ZO) rat model of obesity, insulin resistance, and hypertension has been used to study nephropathy. We hypothesize that chronically elevated intrarenal angiotensin II (ANG II) down-regulates nephrin, a key slit-pore protein and up-regulates fibrogenic molecule transforming growth factor (TGFbeta1) and thus result in progression of nephropathy in type 2 diabetes. Untreated or angiotensin converting enzyme (ACE) inhibitor, captopril, treated ZO and control Lean (ZL) rats were used to measure intrarenal levels of ANG II, glomerular nephrin, TGFbeta1, collagen and fibronectin with age using radioimmunoassay, RT-PCR and immunoblot techniques. Progression of nephropathy was established by measuring proteinuria and sclerosis. ZO rats developed obesity, hyperglycemia, hyperinsulinimia, increase in intrarenal ANG II and proteinuria. Expression of glomerular nephrin decreased while expression of TGFbeta1 and matrix components increased in ZO rats. Captopril treatment prevented increase in intrarenal ANG II, and reversed expression of nephrin, TGFbeta1, collagen and fibronectin. We conclude that in this model of type 2 diabetic nephropathy, chronically elevated intrarenal ANG II causes proteinuria via decrease in nephrin and glomerulosclerosis via TGFbeta1 mediated increase in matrix component.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Animals, Genetically Modified; Blood Pressure; Chromatography; Collagen; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Glucose; Hyperglycemia; Immunoblotting; Insulin; Insulin Resistance; Kidney; Male; Models, Statistical; Obesity; Proteinuria; Radioimmunoassay; Rats; Rats, Zucker; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

Bone morphogenetic proteins (BMPs) and growth differentiation factors (GDFs) control the development and homeostasis of multiple tissue types in many organisms, from humans to invertebrates. These morphogens are expressed in a tissue-specific manner and they signal by binding to serine-threonine kinase receptors, resulting in coordinated changes in gene expression that regulate the differentiation and development of multiple tissue types. In addition, these proteins are regulated post-transcriptionally through binding to several soluble proteins. In this review we focus on a subset of BMPs and GDFs that have been implicated in the pathophysiology of type 2 diabetes and cardiovascular disease.

Topics: Animals; Atherosclerosis; Bone Morphogenetic Protein 7; Bone Morphogenetic Protein Receptors; Bone Morphogenetic Proteins; Cardiovascular Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Growth Differentiation Factor 3; Humans; Hypertension, Pulmonary; Hypoglycemic Agents; Intercellular Signaling Peptides and Proteins; Kidney Diseases; Metabolic Diseases; Signal Transduction; Transforming Growth Factor beta

In this chapter, we summarize our studies on plasminogen activator inhibitor 1 (PAI-1), tissue factor, and transforming growth factor beta (TGF-beta) expression in obesity, using genetically obese mice as a model. These studies emphasize the key role played by the adipocyte, a cell whose numbers, size, and metabolic activity are grossly altered in obesity/NIDDM. They also implicate multiple cytokines, hormones, and growth factors in the abnormal expression of these and perhaps other hemostatic genes by adipocytes in obesity/NIDDM. These studies demonstrate that tumor necrosis factor alpha (TNF-alpha) plays a central role in the expression of hemostatic genes in this disorder.

Topics: Adipocytes; Animals; Diabetes Mellitus; Diabetes Mellitus, Type 2; Gene Expression Regulation; Hemostasis; Humans; Mice; Mice, Obese; Obesity; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Diabetic nephropathy (DN) is characterized structurally by progressive mesangial deposition of extracellular matrix (ECM). Transforming growth factor-ss (TGF-ss) is considered to be one of the major cytokines involved in the regulation of ECM synthesis and degradation. Several studies suggest that an increase in urinary TGF-ss levels may reflect an enhanced production of this polypeptide by the kidney cells. We evaluated TGF-ss in occasional urine samples from 14 normal individuals and 23 patients with type 2 diabetes (13 with persistent proteinuria >500 mg/24 h, DN, 6 with microalbuminuria, DMMA, and 4 with normal urinary albumin excretion, DMN) by enzyme immunoassay. An increase in the rate of urinary TGF-ss excretion (pg/mg U Creat.) was observed in patients with DN (296.07 +/- 330.77) (P<0.001) compared to normal individuals (17.04 +/- 18.56) (Kruskal-Wallis nonparametric analysis of variance); however, this increase was not observed in patients with DMMA (25.13 +/- 11.30) or in DMN (18.16 +/- 11.82). There was a positive correlation between the rate of urinary TGF-ss excretion and proteinuria (r = 0.70, alpha = 0.05) (Pearson's analysis), one of the parameters of disease progression.

Topics: Adult; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Extracellular Matrix; Humans; Kidney; Middle Aged; Proteinuria; Transforming Growth Factor beta

Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gene Expression; Hemostasis; Humans; Mice; Obesity; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Diseases

Plasminogen activator inhibitor-1 is elevated in obesity and may be a risk factor for obesity/NIDDM related cardiovascular disease. In spite of this, little is known about the tissue and cellular origin of elevated PAI-1 in obesity or of the mediators and molecular mechanisms that regulate it. We have begun to systematically address these issues using genetically obese (ob/ob, db/db) mice. Plasma PAI-1 levels were 5-fold higher in obese mice compared to their lean counterparts. Subsequent RT-PCR and in situ hybridization studies suggest that the increased plasma PAI-1 originates primarily from the adipocyte in response to chronically elevated levels of tumor necrosis factor-alpha (TNF-alpha), insulin, and transforming growth factor-beta (TGF-beta). Thus, the signals and mechanisms that lead to elevated plasma PAI-1 observed in obesity are complex, and appear to involve interactions between multiple mediators and the adipose tissue itself.

Topics: Animals; Diabetes Mellitus; Diabetes Mellitus, Type 2; Humans; Mice; Mice, Obese; Models, Genetic; Obesity; Plasminogen Activator Inhibitor 1; Risk Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Diabetic nephropathy (DN) is one of the most important complications of type 2 diabetes (T2DM). Oxidative stress and inflammatory cytokines play an essential role in the development and progression of DN. Despite adopting appropriate therapies, many patients with DN progress to end-stage renal disease (ESRD). Therefore, exploring innovative strategies for better management of DN is crucial. Crocin, a natural compound found in saffron, has profound antioxidant, antifibrotic and anti-inflammatory properties. This study aimed to evaluate the therapeutic effects of crocin in attenuation of the progression of DN.. In this randomized, triple-blind, placebo-controlled clinical trial, 44 patients with T2DM and microalbuminuria were randomly assigned to receive either crocin (15 mg/day) or a placebo for 90 days. Eventually, 40 patients completed the study: 21 patients in the crocin group and 19 in the placebo group. The primary outcome was a change in urine Albumin-to-Creatinine Ratio (uACR) from baseline to the end of the treatment period. We also evaluated metabolic, anthropometric, and biochemical parameters as the secondary outcomes.. The results of the present study showed that uACR increased in both groups, but the increment was not significantly higher in the crocin group compared with the placebo. Serum levels of transforming growth factor-β (TGF-β) decreased in the crocin group and increased in the placebo group, but none of these changes was significant. Crocin significantly reduced triglyceride (TG) as an important metabolic parameter (P-Value = 0.03).. This study has shown that crocin may be a safe and potential adjunct to conventional therapies for DN patients but because of our limitations such as short duration of the treatment period, and prescribing low doses of crocin, we could not achieve the significant level.

Topics: Albumins; Antioxidants; Carotenoids; Creatinine; Cytokines; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Transforming Growth Factor beta; Transforming Growth Factors; Triglycerides

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

Activation of the transforming growth factor beta (TGF-β) pathway is a significant contributor to the pathogenesis of diabetic nephropathy. Carnosine is a dipeptide that can inhibit TGF-β synthesis. We tested the hypothesis that carnosine supplement added to standard therapy will result in reduced urinary TGF-β levels among patients with diabetic nephropathy.. We randomly assigned 40 patients with diabetic nephropathy and albuminuria 30-299 mg/day to treatment with carnosine (2 g/day) or placebo for 12 weeks. Urinary TGF-β level was determined using ELISA, urine albumin was ascertained by immunonephelometric assay, and renal function and metabolic profiles were determined at baseline and during 12 weeks of active treatment. Primary outcome was decrease in urinary levels of TGF-β.. The 2 groups were comparable for baseline characteristics, blood pressure, urine albumin, urine TGF-β and renal function measurements. Urinary TGF-β significantly decreased with carnosine supplement (- 17.8% of the baseline values), whereas it tended to increase with placebo (+ 16.9% of the baseline values) (between-group difference P < 0.05). However, blood urea nitrogen, serum creatinine, glomerular filtration rate and other biochemical parameters remained unchanged during the study period including urinary albuminuria. Both groups were well tolerated with no serious side-effects.. These data indicated an additional renoprotective effect of oral supplementation with carnosine to decrease urinary TGF-β level that serves as a marker of renal injury in diabetic nephropathy.. Thai Clinical Trials, TCTR20200724002 . Retrospectively Registered 24 July 2020.

Topics: Albuminuria; Biomarkers; Blood Urea Nitrogen; Carnosine; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dietary Supplements; Double-Blind Method; Female; Glomerular Filtration Rate; Humans; Male; Middle Aged; Transforming Growth Factor beta

In view of the known vasodilatory effects of glucagon-like peptide-1 and exenatide, we investigated the effects of exenatide on vasoactive factors. We analysed blood samples and mononuclear cells (MNCs) from a previous study, collected after a single dose and 12 weeks of exenatide or placebo treatment in a series of 24 patients with type 2 diabetes mellitus. After exenatide treatment, plasma concentrations of atrial natriuretic peptide, cyclic guanyl monophosphate (cGMP) and cyclic adenyl monophosphate increased significantly at 12 weeks. Plasma cGMP and adenylate cyclase expression in MNCs increased significantly after a single dose. Angiotensinogen concentration fell significantly 2 hours after a single dose and at 12 weeks, while renin and angiotensin II levels fell significantly only after a single dose and not after 12 weeks of treatment. Exenatide also suppressed the plasma concentration of transforming growth factor-β and the expression of P311 in MNCs at 12 weeks. Thus, exenatide induces an increase in a series of vasodilators, while suppressing the renin-angiotensin system. These changes may contribute to the overall vasodilatory effect of exenatide.

Topics: Adenylyl Cyclases; Angiotensinogen; Anti-Obesity Agents; Antihypertensive Agents; Atrial Natriuretic Factor; Blood Pressure; Cyclic AMP; Cyclic GMP; Diabetes Mellitus, Type 2; Exenatide; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Leukocytes, Mononuclear; Nerve Tissue Proteins; Obesity; Oncogene Proteins; Peptides; Renin-Angiotensin System; Reproducibility of Results; Single-Blind Method; Transforming Growth Factor beta; Venoms

The poor glycemic status seems to be an important factor affecting implant complication rates, including peri-implant bone loss.. This trial evaluated the influence of glycemic control of type 2 diabetes mellitus (T2DM) patients on implant stabilization and on the levels of bone markers in peri-implant fluid during the healing.. Systemically healthy patients (SH,n = 19), better-controlled T2DM (BCDM,n = 16), and poorly controlled T2DM (PCDM,n = 16) indicated for implant therapy were recruited. The implant stability quotient (ISQ) was determined at implant placement, 3, 6, and 12 months. Levels of transforming growth factor- β (TGF-β), fibroblast growth factor (FGF), osteopontin (OPN), osteocalcin (OC), and osteoprotegerin (OPG) in the peri-implant fluid were quantified at 15 days, and 3, 6, and 12 months, using the Luminex assay.. OPG and OPN levels were higher in SH at 12 months than at15 days (p < .05), whereas OC and TGF-β were lower in PCDM at 12 months compared with the 15-day and 3-month follow-ups, respectively (p < .05). Inter-group analyses showed lower OPN levels in PCDM compared with SH at 12 months (p < .05). The ISQ was higher at 12 months when compared with baseline and 3 months in SH (p < .05), whereas no differences were observed during follow-up in diabetics, regardless of glycemic control (p > .05). No difference in ISQ was observed among groups over time (p > .05).. Poor glycemic control negatively modulated the bone factors during healing, although T2DM, regardless of glycemic status, had no effect on implant stabilization.

Topics: Adult; Aged; Biomarkers; Blood Glucose; Bone Regeneration; Dental Implants; Diabetes Mellitus, Type 2; Female; Gingival Crevicular Fluid; Humans; Male; Middle Aged; Osteocalcin; Osteopontin; Osteoprotegerin; Single-Blind Method; Transforming Growth Factor beta

A substantial number of people at risk of developing type 2 diabetes could not improve insulin sensitivity by physical training intervention. We studied the mechanisms of this impaired exercise response in 20 middle-aged individuals at high risk of developing type 2 diabetes who performed 8 weeks of controlled cycling and walking training at 80% individual Vo2 peak. Participants identified as nonresponders in insulin sensitivity (based on the Matsuda index) did not differ in preintervention parameters compared with high responders. The failure to increase insulin sensitivity after training correlates with impaired upregulation of mitochondrial fuel oxidation genes in skeletal muscle, and with the suppression of the upstream regulators PGC1α and AMPKα2. The muscle transcriptomes of the nonresponders are further characterized by the activation of transforming growth factor (TGF)-β and TGF-β target genes, which is associated with increases in inflammatory and macrophage markers. TGF-β1 as inhibitor of mitochondrial regulators and insulin signaling is validated in human skeletal muscle cells. Activated TGF-β1 signaling downregulates the abundance of PGC1α, AMPKα2, the mitochondrial transcription factor TFAM, and mitochondrial enzymes. Thus, the data suggest that increased TGF-β activity in skeletal muscle can attenuate the improvement of mitochondrial fuel oxidation after training and contribute to the failure to increase insulin sensitivity.

Topics: Adult; AMP-Activated Protein Kinases; Diabetes Mellitus, Type 2; Exercise; Female; Humans; Insulin Resistance; Male; Middle Aged; Mitochondria; Muscle, Skeletal; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Transforming Growth Factor beta

Management of diabetic foot ulcers (DFUs) is a great challenge for clinicians. Although the oxygen-ozone treatment improves the diabetic outcome, there are few clinical trials to verify the efficacy and illuminate the underlying mechanisms of oxygen-ozone treatment on DFUs. In the present study, a total of 50 type 2 diabetic patients complicated with DFUs, Wagner stage 2~4, were randomized into control group treated by standard therapy only and ozone group treated by standard therapy plus oxygen-ozone treatment. The therapeutic effects were graded into 4 levels from grade 0 (no change) to grade 3 (wound healing). The wound sizes were measured at baseline and day 20, respectively. Tissue biopsies were performed at baseline and day 11. The expressions of vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), and platelet-derived growth factor (PDGF) proteins in the pathologic specimens were determined by immunohistochemical examinations. The effective rate of ozone group was significantly higher than that of control group (92% versus 64%, P < 0.05). The wound size reduction was significantly more in ozone group than in control group (P < 0.001). After treatment, the expressions of VEGF, TGF-β, and PDGF proteins at day 11 were significantly higher in ozone group than in control group. Ozone therapy promotes the wound healing of DFUs via potential induction of VEGF, TGF-β, and PDGF at early stage of the treatment. (Clinical trial registry number is ChiCTR-TRC-14004415).

Topics: Aged; Diabetes Mellitus, Type 2; Female; Foot Ulcer; Humans; Immunohistochemistry; Male; Middle Aged; Oxygen; Ozone; Platelet-Derived Growth Factor; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Wound Healing

Dyslipidemia contributes to endothelial dysfunction in type 2 diabetes mellitus. Fenofibrate (FF), a ligand of the peroxisome proliferator-activated receptor-α (PPARα), has beneficial effects on microvascular complications. FF may act on the endothelium by regulating vasoactive factors, including endothelin-1 (ET-1). In vitro, FF decreases ET-1 expression in human microvascular endothelial cells. We investigated the molecular mechanisms involved in the effect of FF treatment on plasma levels of ET-1 in type 2 diabetes mellitus patients.. FF impaired the capacity of transforming growth factor-β to induce ET-1 gene expression. PPARα activation by FF increased expression of the transcriptional repressor Krüppel-like factor 11 and its binding to the ET-1 gene promoter. Knockdown of Krüppel-like factor 11 expression potentiated basal and transforming growth factor-β-stimulated ET-1 expression, suggesting that Krüppel-like factor 11 downregulates ET-1 expression. FF, in a PPARα-independent manner, and insulin enhanced glycogen synthase kinase-3β phosphorylation thus reducing glycogen synthase kinase-3 activity that contributes to the FF-mediated reduction of ET-1 gene expression. In type 2 diabetes mellitus, improvement of flow-mediated dilatation of the brachial artery by FF was associated with a decrease in plasma ET-1.. FF decreases ET-1 expression by a PPARα-dependent mechanism, via transcriptional induction of the Krüppel-like factor 11 repressor and by PPARα-independent actions via inhibition of glycogen synthase kinase-3 activity.

Topics: Apoptosis Regulatory Proteins; Binding Sites; Brachial Artery; Cell Cycle Proteins; Cell Line; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Down-Regulation; Dyslipidemias; Endothelial Cells; Endothelin-1; Fenofibrate; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Hypolipidemic Agents; Phosphorylation; PPAR alpha; Promoter Regions, Genetic; Repressor Proteins; Signal Transduction; Time Factors; Transcription, Genetic; Transfection; Transforming Growth Factor beta; Vasodilation

End-stage renal disease (ESRD) due to type 2 diabetic nephropathy is a very common condition which is increasing in prevalence, and is associated with high global levels of mortality and morbidity. Both proteinuria and transforming growth factor-β (TGF-β) may contribute to the development of ESRD in patients with diabetic nephropathy. Experimental studies indicate that turmeric improves diabetic nephropathy by suppressing TGF-β. Therefore, this study investigated the effects of turmeric on serum and urinary TGF-β, interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α), as well as proteinuria, in patients with overt type 2 diabetic nephropathy.. A randomized, double-blind and placebo-controlled study was carried out in the Diabetes Clinic of the Outpatient Department of Shiraz University of Medical Sciences on 40 patients with overt type 2 diabetic nephropathy, randomized into a trial group (n = 20) and a control group (n = 20). Each patient in the trial group received one capsule with each meal containing 500 mg turmeric, of which 22.1 mg was the active ingredient curcumin (three capsules daily) for 2 months. The control group received three capsules identical in colour and size containing starch for the same 2 months.. Serum levels of TGF-β and IL-8 and urinary protein excretion and IL-8 decreased significantly comparing the pre- and post-turmeric supplementation values. No adverse effects related to turmeric supplementation were observed during the trial.. Short-term turmeric supplementation can attenuate proteinuria, TGF-β and IL-8 in patients with overt type 2 diabetic nephropathy and can be administered as a safe adjuvant therapy for these patients.

Topics: Administration, Oral; Curcuma; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dietary Supplements; Double-Blind Method; Female; Humans; Interleukin-8; Male; Middle Aged; Phytotherapy; Proteinuria; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Topics: Adult; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Double-Blind Method; Enzyme Inhibitors; Humans; Indoles; Maleimides; Middle Aged; Placebos; Protein Kinase C; Protein Kinase C beta; Transforming Growth Factor beta

Blood pressure and genetic factors are important factors for diabetic nephropathy. We investigated the relationship between the efficacy of renin angiotensin system (RAS) inhibitors and angiotensin-converting enzyme (ACE) genotypes. Patients with type 2 diabetes without proteinuria, were treated with RAS inhibitors, the first being an ACE inhibitor (ACEI) and the second, an angiotensin II (ATII) receptor blocker (ARB) for 8 weeks each. There was no significant difference (except serum ACE activity) between the two treatments. However, by analysis segregated with ACE gene polymorphism, ARB significantly decreased transforming growth factor-beta1 (TGF-beta) compared to ACEI in patients with the I/I genotype but not in patients with the D/I+D/D genotype. DeltaATII and DeltaTGF-beta have a negative correlation with the I/I genotype and a positive correlation with the D/I+D/D genotypes. These correlation coefficients are significantly different. We suggest that in I/I patients, TGF-beta was reduced by ARB via effects on (ATII) type 2 receptors (AT2). In our experiments, the effect of ARB on TGF-beta reduction was only detected by segregation of ACE genotypes. This indicates that the selection of medicine in light of a patient's genotype is important in treating diabetic nephropathy.

Topics: Aged; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Cross-Over Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Genotype; Humans; Male; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Receptor, Angiotensin, Type 2; Renin-Angiotensin System; Transforming Growth Factor beta

We evaluated the renoprotective effects of dual blockade of renin-angiotensin system (RAS) by using a low-dose combination of ACE inhibiter and angiotensin II receptor blocker in type 2 diabetic patients with advanced kidney disease. The amount of proteinuria and the urinary levels of bioassayable TGF-beta1 were used as surrogate markers of renal injury and sclerosis.. We performed a prospective double-blinded randomized crossover trial consisting of three 16-week treatment periods with ramipril alone (10 mg/day), candesartan alone (16 mg/day), and ramipril (5 mg/day) plus candesartan (8 mg/day) combination therapy. Twenty-one type 2 diabetic patients with overt nephropathy with a 24 h urinary protein excretion rate (UPER) of > 1.0 g/24 h and creatinine clearance (Ccr) of 30 to 59 ml/min/1.73 m2 completed the entire study.. Subjects consisted of 10 female and 11 male patients with a mean age of 49 +/- 8 years and duration of diabetes ranging from 4 to 13 years. At baseline, 24-h blood pressures (BPs) were 133 +/- 6/81 +/- 7 mmHg, Ccr 40.6 +/- 4.1 ml/min/1.73 m2, 24-h UPER 4.1 +/- 1.9 g/24 h, and urinary TGF-beta1 level 28.4 +/- 16.1 pg/mg creatinine (cr). Although there was no comparable change in BP and plasma/urinary biochemical parameters, 24-h UPER was significantly reduced by the combination therapy (2.9 +/- 1.4 g/24 h) compared with that of ramipril (3.5 +/- 1.8 g/24 h) and of candesartan (3.3 +/- 2.0 g/24 h) single therapy (P < 0.05). Urinary TGF-beta1 level was reduced in all three therapies compared with that of the control (28.4 +/- 16.1 pg/mg cr) (P < 0.05). However, the combination therapy showed the most significant change (combination 19.6 +/- 10.6 pg/mg cr; ramipril 24.7 +/- 13.3 pg/mg cr; candesartan; 23.4 +/- 11.7 pg/mg cr). No significant or irreversible adverse effect was observed in the 21 patients who completed the entire study.. The dual blockade of RAS with low-dose ramipril plus candesartan was found to be safe and offered additive benefits with respect to reducing proteinuria and urinary TGF-beta1 excretion in diabetic patients with advanced kidney disease. These benefits were evident as compared with single ramipril and candesartan therapies at doses two-fold greater. Further study on the dose-titration is mandatory in terms of safety and especially for maximizing renoprotection in this patient population.

Topics: Adult; Aged; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Benzimidazoles; Biomarkers; Biphenyl Compounds; Creatinine; Cross-Over Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Humans; Male; Middle Aged; Prospective Studies; Ramipril; Renin-Angiotensin System; Tetrazoles; Transforming Growth Factor beta; Treatment Outcome

Increased urinary excretion of protein and transforming growth factor-beta (TGF-beta) are associated with progression of diabetic nephropathy (DN). Thiazolidinediones (TZD) could reduce urinary protein excretion in patients with microalbuminuric DN. There is little data of patients with macroalbuminuric DN. Also, there are no available clinical data regarding the effect of TZD on TGF-beta and type IV collagen in clinical DN. The present study was carried out to evaluate the effect of pioglitazone (PGZ), a member of TZD, on urinary protein, urinary TGF-beta, and urinary type IV collagen excretion in type 2 diabetic patients with macroalbuminuric DN.. Forty patients with type 2 diabetes and overt nephropathy, proteinuria more than 500 mg/day, were randomly assigned to receive PGZ (30 mg/day, n = 24) or placebo (control group, n = 16), for 12 weeks. Blood pressure, plasma glucose, glycated hemoglobin, lipid profile, 24-hour proteinuria, urinary TGF-beta and urinary type IV collagen were determined and compared.. Glycemic control and blood pressure in both groups were not significant different. At baseline, the levels of proteinuria, urinary TGF-beta, and type IV collagen were not significant different between both groups. The geometric mean of urinary protein excretion in the PGZ group was progressively reduced from 1.64 to 0.98 gram/day (g/d), or 40.1% decrease which was significantly different (p < 0.05) from the 4.3% increase (from 1.72 to 1.80 g/d) in the control group. Urinary TGF-beta excretion in the PGZ group was decreased by 47.8% which significantly differed from the 59.7% increase in the control group (p < 0.05). Urinary type IV collagen levels in the PGZ group were decreased by 35% which was slightly, but not significantly, different from the 51.6% elevation in the control group (p = 0.06).. Besides the effectiveness in blood sugar control, pioglitazone could salutarily reduce proteinuria and synthesis of TGF-beta as well as type IV collagen. These beneficial effects of pioglitazone on diabetic nephropathy are comparable to angiotensin converting enzyme inhibitors and angiotensin receptor blockers

Topics: Administration, Oral; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dose-Response Relationship, Drug; Female; Humans; Hypoglycemic Agents; Kidney Function Tests; Male; Middle Aged; Pioglitazone; Probability; Proteinuria; Reference Values; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Single-Blind Method; Thiazolidinediones; Transforming Growth Factor beta; Treatment Outcome

In this study we evaluated the effect of a dual blockade with enalapril and losartan on the reduction of overt macroproteinuria and its potential mechanism(s) in hypertensive patients with type 2 diabetes. Twenty-six hypertensive patients with type 2 diabetes at the baseline were administered 5 mg of enalapril once daily for 12 weeks. At the beginning of the study, the subjects were assigned to receive an add-on of 50 mg of losartan once daily or 5 mg of enalapril once daily for another 12 weeks. Blood samples were collected at the baseline, at the beginning, and at the end of the study for the measurement of laboratory parameters, and these data, including blood pressure, were compared between the two groups. Treatment with 5 mg of enalapril significantly decreased the systolic blood pressure level in both groups, and the addition of losartan and/or enalapril further decreased the levels. There was no difference in blood pressure between the two groups. However, the addition of losartan, but not enalapril, significantly decreased the urinary protein excretion level, plasma aldosterone, and hypersensitive-C-reactive protein at the end of the study. The results established that the dual blockade of angiotensin II with enalapril and losartan has a greater clinical benefit for high-risk patients with hypertension and advanced diabetic nephropathy.

Topics: Aged; Aldosterone; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; C-Reactive Protein; Cystatin C; Cystatins; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enalapril; Female; Humans; Hypertension; Losartan; Male; Middle Aged; Natriuretic Peptide, Brain; Proteinuria; Transforming Growth Factor beta

Studies in rodent models have suggested that reduction in renal transforming growth factor (TGF)-beta1 may underlie the renoprotective effects of the renin-angiotensin system (RAS) blockade. However, the role of the RAS blockade in abrogating TGF-beta in human disease is unknown. Accordingly, we sought to examine TGF-beta gene expression and biological activity in human renal biopsies, before and after ACE inhibition.. RNA was extracted from renal biopsies taken from participants in the Diabiopsies study, a randomized controlled 2-year trial of 4 mg/day perindopril versus placebo that reported a reduction in proteinuria and cortical matrix expansion in type 2 diabetic nephropathy. Biopsies taken at study entry and at 2 years were obtained in 12 patients (6 placebo and 6 taking perindopril). TGF-beta1 and its receptor mRNA were quantified by real-time PCR, and its biological activity was assessed by examining the activation of its intracellular signaling pathway (phosphorylated Smad2) and the expression TGF-beta-inducible gene H3 (betaig-H3).. At baseline, TGF-beta1 expression was similar in both placebo- and perindopril-treated groups and was unchanged over a 2-year period in biopsies of placebo-treated subjects. In contrast, perindopril treatment led to a substantial diminution in TGF-beta1 mRNA (mean 83% reduction, P < 0.05). Phosphorylated Smad2 immunolabeling and betaig-H3 mRNA were similarly reduced with ACE inhibition (P < 0.05) but unchanged in the placebo group. No differences were noted in the gene expression of TGF-beta receptor II in biopsies of either placebo- or perindopril-treated subjects.. This study demonstrates that over a 2-year period, treatment with perindopril in patients with type 2 diabetes and nephropathy leads to a reduction in both renal TGF-beta1 gene expression and its downstream activation.

Topics: Adult; Angiotensin-Converting Enzyme Inhibitors; Diabetes Mellitus, Type 2; Diabetic Nephropathies; DNA Primers; Female; Gene Expression Regulation; Humans; Kidney; Male; Middle Aged; Perindopril; Phosphorylation; Polymerase Chain Reaction; RNA; Smad2 Protein; Transforming Growth Factor beta

Angiotensin II receptor Type 1 antagonists postpone the development of nephropathy in type 2 diabetes mellitus (DM). We hypothesize that Losartan may ameliorate renal function in diabetic patients through the regulation on the generation of transforming growth factor (TGF)-beta and fibrinolytic regulators.. Twenty-two type 2 DM patients with microalbuminuria were treated with 50-100 mg/day of Losartan for 6 months. Urinary secretion of TGF-, plasminogen activator inhibitor-1 (PAI-1), tissue and urokinase plasminogen activators (tPA and uPA) fibronectin, collagen IV and plasma levels of TGF-beta, PAI-1, tPA and uPA of the patients before and after the treatment were analyzed using enzyme-linked immunoabosorbance assay.. Losartan effectively reduced arterial blood pressure and urinary albumin excretion. The levels of TGF-beta in urine, but not in plasma, were reduced after 2, 4 and 6 months of the treatment (-32% to -48%, P < 0.05 or 0.01). Urinary or plasma levels of PAI-1, tPA or uPA, and urinary secretion of fibronectin or collagen IV were not significantly altered by Losartan treatment. Urinary levels of collagen IV positively correlated with uPA, and that of fibronectin negatively correlated with PAI-1 in the patients (P < 0.01). Urinary TGF-beta negatively correlated uPA in urine of the patients (P < 0.01).. Losartan reduced urinary excretion of TGF-beta and albumin in type 2 DM patients with microalbuminuria. Fibrinolytic regulators and TGF-beta are implicated in the regulation of ECM turnover in kidneys of the patients with diabetic nephropathy.

Topics: Adult; Aged; Albuminuria; Angiotensin II Type 1 Receptor Blockers; Blood Coagulation Factors; Blood Pressure; Cholesterol; Collagen Type IV; Creatine; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Female; Fibronectins; Glycated Hemoglobin; Humans; Lipids; Losartan; Male; Middle Aged; Plasminogen Activator Inhibitor 1; Plasminogen Activators; Potassium; Regression Analysis; Transforming Growth Factor beta; Treatment Outcome

Diabetic nephropathy is major long-term complication of diabetes mellitus a social and civilization-related disease. At present, the most sensitive and non-invasive indicator of the progression of diabetic nephropathy is microalbuminuria. Morphological features such as accumulation of extracellular matrix proteins, thickening of glomerules' basement membranes are prior to microalbuminuria. The aim of our clinical study was to establish whether urine and serum TGF-beta 1 and IL-6 levels may be significant in prognosing and evaluating a risk for developing diabetic nephropathy. The trial was carried out in 68 patients with type II diabetes mellitus and a group of 10 healthy subjects served as control. Urine and serum TGF-beta 1 concentrations were evaluated, as well as, basic laboratory parameters. After one-year-observation serum creatinine level and microalbuminuria value were investigated in 60 patients with type II diabetes mellitus. In patients with type II diabetes mellitus both urine and serum TGF-beta 1 and IL-6 were elevated. After one-year-observation of patients with type II diabetes mellitus it was established that the increase of serum creatinine concentrations values were higher in those patients, whose initial TGF-beta 1 levels exceeded normal values. A positive correlation between urine TGF-beta 1 level and the progression of renal failure measured by the increase of serum creatinine level was observed. In conclusion, our findings indicate that urine TGF-beta 1 and IL-6 levels may be a good prognostic factor of the development of diabetic nephropathy in the course of diabetes mellitus.

Topics: Adult; Albuminuria; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Female; Humans; Interleukin-6; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1

Transforming growth factor-beta (TGF-beta) is a prosclerotic growth factor implicated in the pathogenesis of diabetic nephropathy. In addition to high glucose, other factors implicated in renal fibrosis and increased TGF-beta synthesis include angiotensin II and high dietary sodium intake. The aim of this study was to examine the effect of angiotensin receptor blockade (ARB) and dietary sodium restriction on the plasma concentration and urinary excretion of TGF-beta in hypertensive patients with type 2 diabetes and elevated albumin excretion rate (AER).. Twenty-one subjects with hypertension and AER between 10 and 200 microg/min were randomized to receive either 50 mg losartan daily (n = 11) or placebo (n = 10). Drug therapy was given in two 4-week phases, separated by a 4-week washout period. In the last 2 weeks of each phase, patients were assigned to regular- or low-sodium diets in random order. Parameters measured at week 0 and 4 of each phase included plasma TGF-beta concentration, TGF-beta urinary excretion, AER, clinic mean arterial blood pressure, and urinary sodium excretion.. Plasma TGF-beta was unaffected by losartan treatment or sodium intake. In the losartan group, urinary TGF-beta excretion decreased by 23.2% (-39.2 and 13.6) [median (interquartile range)] and 38.5% (-46.8 and -6.1) in the regular- and low-sodium phases, respectively (P < 0.05 for drug effect). In the placebo group, median changes of 0.0% (-12.1 and 44.4) and 0.0% (-29.2 and 110.7) occurred in the regular- and low-sodium phases, respectively. Sodium restriction did not affect urinary TGF-beta excretion in either losartan- or placebo-treated patients (P = 0.54 for overall dietary effect), and there was no evidence of interaction between drug and diet (P = 0.29).. In hypertensive type 2 diabetic patients with elevated AER, the ARB losartan, but not sodium restriction, reduced urinary TGF-beta excretion. These data suggest that the renoprotective effects of losartan in patients with type 2 diabetes and nephropathy may include a reduction in renal TGF-beta production.

Topics: Albuminuria; Analysis of Variance; Angiotensin Receptor Antagonists; Antihypertensive Agents; Blood Pressure; Body Mass Index; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diet, Sodium-Restricted; Female; Glycated Hemoglobin; Humans; Hypertension; Losartan; Male; Middle Aged; Placebos; Regression Analysis; Sodium; Transforming Growth Factor beta

The aim of the present study was to determine the effect of losartan on transforming growth factor-beta1 (TGF-beta1) plasma levels and urinary albumin excretion (UAE) in patients with type 2 diabetes mellitus, mild hypertension and microalbuminuria.. Fourteen patients (eight males, aged 55+/-6 years) with type 2 diabetes mellitus, mild arterial hypertension and microalbuminuria, participating in an open, uncontrolled, pilot study were included. Patients were treated for 8 weeks with losartan. TGF-beta1 plasma levels, UAE and 24-h blood pressure monitoring were determined at baseline and at 4 and 8 weeks.. At 4 and 8 weeks of treatment, a reduction was observed in TGF-beta1 plasma levels (5.5+/-4.5 vs 2.0+/-0.6 and 2.6+/-1.0 ng/ml, P<0.005), UAE (96+/-65 vs 59+/-59 and 64+/-47 microg/min, P<0.01), 24-h systolic blood pressure (136+/-9 vs 129+/-9 and 130+/-10 mmHg, P<0.01) and 24-h diastolic blood pressure (77+/-9 vs 74+/-8 and 74+/-7 mmHg, P<0.03). Stratifying the patients by baseline TGF-beta1, seven had TGF-beta1 plasma values higher than normal controls. At 4 and 8 weeks, they showed a marked reduction in TGF-beta1 values (9.0+/-3.9 to 2.1+/-0.7 and 2.5+/-0.7 ng/ml, P<0.01) and UAE (106+/-83 to 49+/-42 and 38+/-26 microg/min, P<0.05), with good correlation between the percentage reduction of both parameters (r=0.83, P<0.01). The remaining seven patients, with normal baseline TGF-beta1 plasma levels, showed no change in TGF-beta1 plasma levels and UAE after treatment.. Treatment with losartan decreases TGF-beta1 plasma values and UAE in type 2 diabetes mellitus patients with high baseline TGF-beta1 levels, suggesting that TGF-beta1 may be a marker to detect patients who may particularly benefit from renin-angiotensin system blockade.

Topics: Albuminuria; Antihypertensive Agents; Blood Pressure; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diastole; Female; Humans; Hypertension; Losartan; Male; Middle Aged; Pilot Projects; Systole; Transforming Growth Factor beta

Diabetes mellitus is a leading cause of end-stage renal disease in the Western world. Histologically, mesangial expansion with increased extracellular matrix protein is observed in patients with diabetic nephropathy. Because transforming growth factor (TGF)-beta promotes extracellular matrix production in response to high glucose, TGF-beta is considered to play a central role in the pathogenesis of diabetic nephropathy. We investigated the association of TGF-beta1 T29C polymorphism and the progression of diabetic nephropathy. Forty patients with type 2 diabetes mellitus were enrolled. All patients had had diabetes for more than 10 years. DNA was extracted from peripheral blood cells, and genotype was determined using real-time polymerase chain reaction method. Patients were classified into three groups according to genotype: TT, TC, and CC. Grade of diabetic nephropathy was determined using the amount of urinary excretion of albumin. Demographic characteristics of the patients with each genotype were not statistically different. No differences in the glycemic control and the mode of therapy were observed. Among patients with three genotypes, the severity of diabetic nephropathy was not statistically different. The patients with TT genotype tended to have a higher rate of progression of nephropathy; however, no statistically significant difference was observed among the three groups. Our results suggest that TGF-beta1 T29C polymorphism is not associated with the progression of diabetic nephropathy. Further studies are required to determine the exact role of this polymorphism in the progression of diabetic nephropathy.

Topics: Aged; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Genotype; Humans; Middle Aged; Polymorphism, Genetic; Transforming Growth Factor beta; Transforming Growth Factor beta1

Transforming growth factor ss (TGF-ss) is an immunosuppressor. It plays a role in regulating cell proliferation, and deletion of its gene in transgenic mice leads to an autoimmune-like disorder. A role of this cytokine has been proposed in the pathogenesis of type 1 diabetes and probably type 2 diabetes. Previous studies had shown an elevated serum level in type 2 diabetes and a reduced serum level in type 1 diabetes; however, these studies did not address the onset of the alterations of TGF-ss with regard to the duration of diabetes. In this study, we compared the levels of TGF-ss in the serum of groups of patients with type 1 and type 2 diabetes mellitus divided according to the duration of their disease. Twenty-six normoalbuminuric patients with type 1 diabetes and 25 normoalbuminuric patients with type 2 diabetes were divided into three groups according to the onset of their diabetes and were compared with 27 and 15 age-matched normal subjects, respectively. We conclude that in normoalbuminuric patients serum TGF-ss levels increased at the onset of type 2 diabetes and remained elevated throughout the disease; they did not change at the onset of type1 diabetes, however, they started to decrease around 2 yr after the onset of the disease.

Topics: Adolescent; Adult; Aging; Albuminuria; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Humans; Male; Time Factors; Transforming Growth Factor beta

Nerve growth factor (NGF) and transforming growth factor-beta2 (TGF-beta2) are cytokines which have known immunological effects. An elevated level of NGF has been reported in certain autoimmune diseases, whereas TGF-beta2 is an immunosuppressor which is known to play a role in regulating cell proliferation. A role of this cytokine has been proposed in the pathogenesis of type-1 diabetes mellitus (IDDM), but no clinical studies have yet measured its serum level in this disease. In this study we measured the levels of NGF and TGF-beta2 in the sera of patients with IDDM (n = 26) and values were compared to those of age-matched normal subjects (n = 27) and also to patients with type-2 diabetes mellitus (NIDDM) (n = 26) with similar HbA1c levels and an equal duration of diabetes. Serum NGF levels were significantly elevated in IDDM patients compared to those of age-matched controls (p <.001) and NIDDM controls (p <.01). TGF-beta2 levels were lower in IDDM patients when compared with the healthy control (p <.001) and the NIDDM control (p <.05). There was no correlation between the levels of NGF and TGF-beta2. The duration of diabetes and the level of HbA1c did not affect the NGF and TGF-beta2 levels in the IDDM patients. We conclude that an increase in NGF and a suppression in TGF-beta2 levels are present in patients with type-1 diabetes mellitus and that both cytokines may play independent roles in the pathogenesis of this disease.

Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Humans; Male; Middle Aged; Nerve Growth Factor; Reference Values; Transforming Growth Factor beta

We studied the urinary excretion of transforming growth factor-beta 1 (TGF-beta 1), platelet-derived growth factor-BB (PDGF) and fibronectin (FN) in 104 patients (52 normoalbuminuric, 24 microalbuminuric, and 28 with overt diabetic nephropathy) with insulin-dependent diabetes mellitus (IDDM) of a long duration and in 30 non-diabetic controls. IDDM patients had higher urinary excretion of TGF-beta 1, PDGF and FN compared to controls. Urinary excretion of TGF-beta 1 and PDGF was elevated in all IDDM subgroups, while FN excretion was significantly increased only in patients with macroalbuminuria. Urinary excretion of TGF-beta 1 and FN did not differ between normoalbuminuric IDDM patients with long duration of diabetes, a group at low risk of ever developing diabetic nephropathy, and IDDM patients with incipient or overt diabetic nephropathy. Excretion of PDGF was significantly higher in patients with micro- and macroalbuminuria compared to normoalbuminuric patients, but there was a considerable overlap between the groups. In conclusion, although longitudinal follow-up studies are needed to further clarify the issue, our results in long-standing IDDM do not support a hypothesis of urinary excretion of TGF-beta 1, PDGF or FN to predict development of diabetic nephropathy.

Topics: Adult; Albuminuria; Anticoagulants; Becaplermin; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Fibronectins; Humans; Male; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Recombinant Proteins; Transforming Growth Factor beta

Leucine-rich α-2 glycoprotein 1 (LRG1) was recently identified as an amplifier of transforming growth factor-β (TGF-β)-induced kidney fibrosis in animal models. We aimed to study whether urine LRG1 is associated with risk of progression to end-stage kidney disease (ESKD) in individuals with type 2 diabetes.. A total of 1,837 participants with type 2 diabetes and estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m2 were recruited from a regional hospital and a primary care facility. Association of urine LRG1 with risk of ESKD (progression to sustained eGFR <15 mL/min/1.73 m2, dialysis, or death resulting from renal causes) was assessed by survival analyses.. During a median follow-up of 8.6 (interquartile range 5.8-9.6) years, 134 incident ESKD events were identified. Compared with those in the lowest tertile, participants with baseline urine LRG1 in the highest tertile had a 1.91-fold (95% CI 1.04-3.50) increased risk of progression to ESKD, after adjustment for cardiorenal risk factors, including eGFR and albuminuria. As a continuous variable, 1 SD increment in urine LRG1 was associated with a 1.53-fold (95% CI 1.19-1.98) adjusted risk of ESKD. Of note, the association of urine LRG1 with ESKD was independent of plasma LRG1. Moreover, urine LRG1 was associated with rapid kidney function decline and progression to macroalbuminuria, two common pathways leading to ESKD.. Urine LRG1, a TGF-β signaling modulator, predicts risk of progression to ESKD independently of clinical risk factors in patients with type 2 diabetes, suggesting that it may be a novel factor involved in the pathophysiological pathway leading to kidney disease progression.

Topics: Diabetes Mellitus, Type 2; Disease Progression; Glomerular Filtration Rate; Glycoproteins; Humans; Kidney Failure, Chronic; Leucine; Transforming Growth Factor beta

Alcohol consumption exacerbates liver abnormalities in animal models, but whether it increases the severity of liver disease in early diabetic or prediabetic rats is unclear. To investigate the molecular mechanisms underlying alcohol-induced liver steatosis or hepatitis, we used a prediabetic animal model. Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Fatty (LETO) rats were pair-fed with an ethanol-containing liquid diet for 6 weeks. Compared with controls, OLETF and LETO rats displayed more pronounced liver steatosis and higher plasma levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamate pyruvate transaminase (SPGT), indicating liver injury. Ethanol-fed LETO (Pd-L-E) rats showed mild liver steatosis and no inflammation compared with ethanol-fed OLETF (Pd-O-E) rats. Although precursor and active SREBP-1 levels in the liver of ethanol-fed OLETF rats significantly increased compared with control diet-fed OLETF rats (Pd-O-C), those of Pd-L-E rats did not. Bone morphogenetic protein (BMP) and TGF-β1 balance in Pd-O-E rats was significantly altered because BMP signaling was upregulated by inducing BMP2, BMP4, BMP7, BMP9, Smad1, and Smad4, whereas TGF-β1, Smad3, and Erk were downregulated. Activation of TGF-β/Smad signaling inhibited BMP2 and BMP9 expression and increased epithelial-mesenchymal transition (EMT) marker levels (Hepcidin, Snail, and Twist) in the liver of LETO rats. Livers of ethanol-fed OLETF rats showed increased levels of vimentin, FSP-1, α-SMA, MMP1, MMP13, and collagen III compared with rats of other groups, whereas EMT marker levels did not change. Thus, BMP exerted anti- and/or pro-fibrotic effects in ethanol-fed rats. Therefore, BMP and TGF-β, two key members of the TGF-β superfamily, play important but diverse roles in liver steatosis in young LETO and OLETF rats.

Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Ethanol; Male; Non-alcoholic Fatty Liver Disease; Prediabetic State; Rats; Rats, Inbred OLETF; Transforming Growth Factor beta; Transforming Growth Factor beta1

Physical exercise is a process of increasing contraction of skeletal muscles involving several organ systems to increase energy formation and it is one of the pillars for the management of type 2 diabetes mellitus (TDM2). T2DM affects the expression of the TGF-β gene.. This study aims to determine the effect of moderate intensity continuous training and slow interval training in expression of TGF-β gene in wistar rats T2DM model.. A moderate intensity continuous training physical activity given to the diabetic rat group in the form of running on a treadmill with a running speed of 20 m/min for 30 minutes while the slow type interval training physical activity given to the diabetic rat group was in the form of running on a treadmill with a running speed of 20 m/minute for 10 repetition sessions, with a duration of 2 minutes per session with interspersed active breaks for 1 minute. TGF-β gene expression was measured using real-time methods.. The results in the continuous group, TGF-β significant decreased p < 0.05. In the interval group, TGF- β insignificant decreased p > 0.05. Moderate intensity continuous training was insignificantly better at decreasing the expression of the TGF-β genes.. This research concluded that there is an effect of moderate intensity continuous training and slow interval training on the expression of TGF-β genes in wistar rats T2DM.

Topics: Animals; Diabetes Mellitus, Type 2; Gene Expression; Physical Conditioning, Animal; Rats; Rats, Wistar; Transforming Growth Factor beta

Obesity is linked to cardiometabolic diseases, however non-obese individuals are also at risk for type 2 diabetes (T2D) and cardiovascular disease (CVD). White adipose tissue (WAT) is known to play a role in both T2D and CVD, but the contribution of WAT inflammatory status especially in non-obese patients with cardiometabolic diseases is less understood. Therefore, we aimed to find associations between WAT inflammatory status and cardiometabolic diseases in non-obese individuals.. In a population-based cohort containing non-obese healthy (n = 17), T2D (n = 16), CVD (n = 18), T2D + CVD (n = 19) individuals, seventeen different cytokines were measured in WAT and in circulation. In addition, 13-color flow cytometry profiling was employed to phenotype the immune cells. Human T cell line (Jurkat T cells) was stimulated by rCCL18, and conditioned media (CM) was added to the in vitro cultures of human adipocytes. Lipolysis was measured by glycerol release. Blocking antibodies against IFN-γ and TGF-β were used in vitro to prove a role for these cytokines in CCL18-T-cell-adipocyte lipolysis regulation axis.. In CVD, T2D and CVD + T2D groups, CCL18 and CD4. We suggest that in T2D and CVD, increased production of CCL18 recruits and activates CD4

Topics: Adipose Tissue; Adipose Tissue, White; Cardiovascular Diseases; CD4-Positive T-Lymphocytes; Chemokines, CC; Cytokines; Diabetes Mellitus, Type 2; Glycerol; Humans; Obesity; T-Lymphocytes; Transforming Growth Factor beta

Regulatory T cells (Tregs) play a remarkable role in modulating post-ischemic neuroinflammation. However, the characteristics of Tregs in diabetic ischemic stroke remain unknown.. Transient middle cerebral artery occlusion (MCAO) was conducted on leptin receptor-mutated db/db mice and db/+ mice. The number, cytokine production, and signaling features of Tregs in peripheral blood and ipsilateral hemispheres were evaluated by flow cytometry. Treg plasticity was assessed by the adoptive transfer of splenic Tregs into mice. The effect of ipsilateral macrophages/microglia on Treg plasticity was determined by. db/db mice had more infiltrating Tregs in their ipsilateral hemispheres than db/+ mice. Infiltrating Tregs in db/db mice expressed higher transforming growth factor-β (TGF-β), interleukin-10 (IL-10), forkhead box P3 (Foxp3), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and T-box expressed in T cells (T-bet) in comparison to infiltrating Tregs in db/+ mice, suggesting promoted generation of T helper 1 (Th1)-like Tregs in the brains of db/db mice after stroke. The post-ischemic brain microenvironment of db/db mice significantly up-regulated IFN-γ, TNF-α, T-bet, IL-10, and TGF-β in infiltrating Tregs. Moreover, ipsilateral macrophages/microglia remarkably enhanced the expression of IFN-γ, TNF-α, and T-bet but not IL-10 and TGF-β in Tregs. db/db macrophages/microglia were more potent in up-regulating IFN-γ, TNF-α, and T-bet than db/+ macrophages/microglia. Interleukin-12 (IL-12) blockage partially abolished the modulatory effect of macrophages/microglia on Tregs.. The generation of Th1-like Tregs was promoted in the brains of type 2 diabetic mice after stroke. Our study reveals significant Treg plasticity in diabetic stroke.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Forkhead Transcription Factors; Infarction, Middle Cerebral Artery; Interferon-gamma; Interleukin-10; Interleukin-12; Mice; Phosphates; STAT1 Transcription Factor; STAT5 Transcription Factor; Stroke; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Transforming Growth Factors; Tumor Necrosis Factor-alpha

Activation of hepatic stellate cells (HSCs), the central event of fibrosis, indicates the severe stage of non-alcoholic fatty liver disease (NAFLD). MicroRNAs (miRNAs) participate in this process. Treatment with a sodium-glucose cotransporter 2 inhibitor (SGLT2i) alleviates liver fibrosis in patients with type 2 diabetes and NAFLD; however, the role of SGLT2i in ameliorating liver fibrosis in NAFLD by regulating miRNAs remains unclear.. We monitored the expression of NAFLD-associated miRNAs in the livers of two NAFLD models and observed high expression of miR-34a-5p. miR-34a-5p was highly expressed in mouse primary liver non-parenchymal cells and LX-2 HSCs, and this miRNA was positively correlated with alanine transaminase levels in NAFLD models. Overexpression of miR-34a-5p enhanced LX-2 activation, whereas its inhibition prevented HSCs activation by regulating the TGFβ signaling pathway. The SGLT2i empagliflozin significantly downregulated miR-34a-5p, inhibited the TGFβ signaling pathway, and ameliorated hepatic fibrosis in NAFLD models. Subsequently, GREM2 was identified as a direct target of miR-34a-5p through database prediction and a dual-luciferase reporter assay. In LX-2 HSCs, the miR-34a-5p mimic and inhibitor directly downregulated and upregulated GREM2, respectively. Overexpressing GREM2 inactivated the TGFβ pathway whereas GREM2 knockdown activated it. Additionally, empagliflozin upregulated Grem2 expression in NAFLD models. In methionine- and choline-deficient diet-fed ob/ob mice, a fibrosis model, empagliflozin downregulated miR-34a-5p and upregulated Grem2 to improve liver fibrosis.. Empagliflozin ameliorates NAFLD-associated fibrosis by downregulating miR-34a-5p and targeting GREM2 to inhibit the TGFβ pathway in HSCs.

Topics: Animals; Diabetes Mellitus, Type 2; Fibrosis; Hepatic Stellate Cells; Liver; Liver Cirrhosis; Mice; MicroRNAs; Non-alcoholic Fatty Liver Disease; Sodium-Glucose Transporter 2 Inhibitors; Transforming Growth Factor beta

Hepatic fibrosis is the primary determinant of mortality in patients with metabolic dysfunction-associated steatohepatitis (MASH). Transforming growth factor-β (TGFβ), a master profibrogenic cytokine, is a promising therapeutic target that has not yet been translated into an effective therapy in part because of liabilities associated with systemic TGFβ antagonism. We have identified that soluble folate receptor γ (FOLR3), which is expressed in humans but not in rodents, is a secreted protein that is elevated in the livers of patients with MASH but not in those with metabolic dysfunction-associated steatotic liver disease, those with type II diabetes, or healthy individuals. Global proteomics showed that FOLR3 was the most highly significant MASH-specific protein and was positively correlated with increasing fibrosis stage, consistent with stimulation of activated hepatic stellate cells (HSCs), which are the key fibrogenic cells in the liver. Exposure of HSCs to exogenous FOLR3 led to elevated extracellular matrix (ECM) protein production, an effect synergistically potentiated by TGFβ1. We found that FOLR3 interacts with the serine protease HTRA1, a known regulator of TGFBR, and activates TGFβ signaling. Administration of human FOLR3 to mice induced severe bridging fibrosis and an ECM pattern resembling human MASH. Our study thus uncovers a role of FOLR3 in enhancing fibrosis.

Topics: Animals; Diabetes Mellitus, Type 2; Fatty Liver; Folic Acid; Hepatic Stellate Cells; Humans; Mice; Transforming Growth Factor beta

Metformin is a widespread antidiabetic agent that is commonly used as a treatment against type 2 diabetes mellitus patients. Regarding its therapeutic potential, multiple studies have concluded that Metformin exhibits antineoplastic activity on several types of cancer, including endometrial carcinoma. Although Metformin's antineoplastic activity is well documented, its cellular and molecular anticancer mechanisms are still a matter of controversy because a plethora of anticancer mechanisms have been proposed for different cancer cell types. In this study, we addressed the cellular and molecular mechanisms of Metformin's antineoplastic activity by using both in vitro and in vivo studies of Pten-loss driven carcinoma mouse models. In vivo, Metformin reduced endometrial neoplasia initiated by Pten-deficiency. Our in vitro studies using Pten-deficient endometrial organoids focused on both cellular and molecular levels in Metformin's tumor suppressive action. At cellular level, we showed that Metformin is involved in not only the proliferation of endometrial epithelial cells but also their regulation via a variety of mechanisms of epithelial-to-mesenchymal transition (EMT) as well as TGF-β-induced apoptosis. At the molecular level, Metformin was shown to affect the TGF-β signalling., a widely known signal that plays a pivotal role in endometrial carcinogenesis. In this respect, Metformin restored TGF-β-induced apoptosis of Pten-deficient endometrial organoids through a p38-dependent mechanism and inhibited TGF-β-induced EMT on no-polarized endometrial epithelial cells by inhibiting ERK/MAPK signalling. These results provide new insights into the link between the cellular and molecular mechanism for Metformin's antineoplastic activity in Pten-deficient endometrial cancers.

Topics: Animals; Antineoplastic Agents; Cell Proliferation; Diabetes Mellitus, Type 2; Endometrial Neoplasms; Female; Humans; Metformin; Mice; Transforming Growth Factor beta

The most frequently prescribed first-line treatment for type II diabetes mellitus is metformin. Recent reports asserted that this diabetes medication can also shield users from cancer. Metformin induces cell cycle arrest in cancer cells. However, the exact mechanism by which this occurs in the cancer system is yet to be elucidated. Here, we investigated the impact of metformin on cell cycle arrest in cancer cells utilizing transforming growth factor (TGF)-beta pathway. TGF-ß pathway has significant effect on cell progression and growth. In order to gain an insight on the underlying molecular mechanism of metformin's effect on TGF beta receptor 1 kinase, molecular docking was performed. Metformin was predicted to interact with transforming growth factor (TGF)-beta receptor I kinase based on molecular docking and molecular dynamics simulations. Furthermore, pharmacophore was generated for metformin-TGF-ßR1 complex to hunt for novel compounds having similar pharmacophore as metformin with enhanced anti-cancer potentials. Virtual screening with 29,000 natural compounds from NPASS database was conducted separately for the generated pharmacophores in Ligandscout® software. Pharmacophore mapping showed 60 lead compounds for metformin-TGF-ßR1 complex. Molecular docking, molecular dynamics simulation for 100 ns and ADMET analysis were performed on these compounds. Compounds with CID 72473, 10316977 and 45140078 showed promising binding affinities and formed stable complexes during dynamics simulation with aforementioned protein and thus have potentiality to be developed into anti-cancer medicaments.

Topics: Diabetes Mellitus, Type 2; Humans; Ligands; Metformin; Molecular Docking Simulation; Molecular Dynamics Simulation; Neoplasms; Pharmacophore; Transforming Growth Factor beta

Diabetes is a common, complex, chronic metabolic disease. A randomized, double-blind, placebo-parallel controlled clinical study has shown that Gegen Qinlian Decoction (GQD) can reduce glycosylated hemoglobin in type 2 diabetes mellitus (T2DM) intestinal damp-heat syndrome patients in a dose-dependent manner.. To explore the pathogenesis of T2DM intestinal damp-heat syndrome and the therapeutic effect of GQD from the perspective of exosomal microRNA (miRNA).. Eligible patients were selected and treated with GQD for 3 months to evaluate their clinical efficacy. Effective cases were matched with healthy volunteers, and saliva samples were collected. Exosomal miRNA was extracted from saliva and analyzed by chip sequencing. Subsequently, the function of the differential gene and the signal transduction pathway were analyzed using bioinformatics technology. Finally, three target miRNAs were randomly selected from the T2DM group/healthy group, and two target miRNAs in the T2DM before treatment/after treatment group were randomly selected for qPCR verification. Finally, we conducted a correlation analysis of the miRNAs and clinical indicators. The registration number for this research is ChiCTR-IOR-15006626.. (1) The expression of exosomal miRNA chips showed that there were 14 differentially expressed miRNAs in the T2DM group/healthy group, and 26 differentially expressed miRNAs in the T2DM before treatment/after treatment group. (2) Enrichment results showed that in the T2DM group/healthy group, it was primarily related to cell development, body metabolism, TGF-β, and ErbB signaling pathways. In the T2DM before treatment/after treatment group, it was mainly related to cellular metabolic regulation processes, and insulin, Wnt, and AMPK signaling pathways. (3) The qPCR verification showed that the expressions of hsa-miR-9-5p, hsa-miR-150-5p, and hsa-miR-216b-5p in the T2DM group was higher (P<0.05). Following GQD treatment, hsa-miR-342-3p and hsa-miR-221-3p were significantly downregulated (P<0.05). (4) hsa-miR-9-5p was positively correlated with BMI (P<0.05), and hsa-miR-150-5p was positively correlated with total cholesterol and triglycerides (P<0.05). The GQD efficacy-related gene hsa-miR-342-3p was positively correlated with the patient's initial blood glucose level (P<0.05), and hsa-miR-221-3p was positively correlated with total cholesterol and triglycerides (P<0.05).. The exosomal miRNA expression profile and signaling pathways related to T2DM intestinal damp-heat syndrome and the efficacy of GQD were established, which provides an alternative strategy for precision traditional Chinese medicine treatment.

Topics: Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Exosomes; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Intestines; Male; Medicine, Chinese Traditional; MicroRNAs; Middle Aged; Patient Acuity; Sequence Analysis, RNA; Signal Transduction; Transforming Growth Factor beta; Treatment Outcome

Kidney fibrosis is considered the final convergent pathway for progressive chronic kidney diseases, but there is still a paucity of success in clinical application for effective therapy. We recently demonstrated that the expression of secreted leucine-rich α-2 glycoprotein-1 (LRG1) is associated with worsened kidney outcomes in patients with type 2 diabetes and that LRG1 enhances endothelial transforming growth factor-β signaling to promote diabetic kidney disease progression. While the increased expression of LRG1 was most prominent in the glomerular endothelial cells in diabetic kidneys, its increase was also observed in the tubulointerstitial compartment. Here, we explored the potential role of LRG1 in kidney epithelial cells and TGF-β-mediated tubulointerstitial fibrosis independent of diabetes. LRG1 expression was induced by tumor necrosis factor-α in cultured kidney epithelial cells and potentiated TGF-β/Smad3 signal transduction. Global Lrg1 loss in mice led to marked attenuation of tubulointerstitial fibrosis in models of unilateral ureteral obstruction and aristolochic acid fibrosis associated with concomitant decreases in Smad3 phosphorylation in tubule epithelial cells. In mice with kidney epithelial cell-specific LRG1 overexpression, while no significant phenotypes were observed at baseline, marked exacerbation of tubulointerstitial fibrosis was observed in the obstructed kidneys. This was associated with enhanced Smad3 phosphorylation in both kidney epithelial cells and α-smooth muscle actin-positive interstitial cells. Co-culture of kidney epithelial cells with primary kidney fibroblasts confirmed the potentiation of TGF-β-mediated Smad3 activation in kidney fibroblasts through epithelial-derived LRG1. Thus, our results indicate that enhanced LRG1 expression-induced epithelial injury is an amplifier of TGF-β signaling in autocrine and paracrine manners promoting tubulointerstitial fibrosis. Hence, therapeutic targeting of LRG1 may be an effective means to curtail kidney fibrosis progression in chronic kidney disease.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelial Cells; Fibrosis; Glycoproteins; Humans; Kidney; Leucine; Mice; Smad3 Protein; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factors; Ureteral Obstruction

Hyperinsulinemia is an important causative factor of prostate enlargement in type 2 diabetes (T2D), however, clinically prostate weight increases during hypoinsulinemic condition. To investigate the pathogenesis of prostate enlargement and effects of phosphodiesterase 5 inhibitor (PDE5i), male Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) rats were used as T2D and control, respectively.. OLETF and LETO rats were treated with oral tadalafil (100 μg/kg/day) or vehicle for 12 wks from at the age of 36 wks.. Prostate weight of OLETF rats was significantly higher than that of LETO at 36 wks, and increased at 48 wks. In OLETF rats, prostate blood flow was significantly lower at 48 wks versus 36 wks. Twelve-week-tadalafil treatment increased prostate blood flow and suppressed prostate weight increase in both strains. This change was inversely correlated with changes in prostate expressions of hypoxia-inducible factor-1 alpha (HIF-1α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Increases with age were observed in mRNA and/or protein levels of cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-α) and cell growth factors insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor (bFGF), and transforming growth factor-beta (TGF-β); especially IL-6, TNF-α, IGF-1, bFGF and TGF-β increased with T2D. Tadalafil suppressed these cytokines and growth factors.. These data suggest chronic ischemia caused by T2D leads to oxidative stress, resulting in prostate enlargement through upregulation of several cytokines and growth factors. Treatment with PDE5i improves prostate ischemia and might prevent enlargement via suppression of cytokines and growth factors in T2D.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Insulin-Like Growth Factor I; Male; Phosphodiesterase 5 Inhibitors; Prostate; Rats; Rats, Inbred OLETF; Rats, Long-Evans; Tadalafil; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Weight Gain

The incidence and prevalence of type 2 diabetes are increasing with age. Nevertheless, there is lack of sensitive diagnostic tools and effective therapeutic regimens. We aimed to establish and verify a practical and valid diagnostic tool for this disease.. WGCNA was presented on the expression profiling of type 2 diabetic and normal islets in combined GSE25724 and GSE38642 datasets. By LASSO Cox regression analyses, a gene signature was constructed based on the genes in diabetes-related modules. ROC curves were plotted for assessing the diagnostic efficacy. Correlations between the genes and immune cell infiltration and pathways were analyzed. BST2 and BTBD1 expression was verified in glucotoxicity-induced and normal islet. Totally, 14 coexpression modules were constructed, and red and cyan modules displayed the correlations to diabetes. The LASSO gene signature (BST2, BTBD1, IFIT1, IFIT3, and RTP4) was developed. The AUCs in the combined datasets and GSE20966 dataset were separately 0.914 and 0.910, confirming the excellent performance in diagnosing type 2 diabetes. Each gene in the model was distinctly correlated to immune cell infiltration and key signaling pathways (TGF-. Our findings propose a gene signature with high efficacy to diagnose type 2 diabetes, which could assist and improve early diagnosis and therapy.

Topics: Diabetes Mellitus, Type 2; Humans; Insulin-Secreting Cells; ROC Curve; Transforming Growth Factor beta; Tumor Suppressor Protein p53

Triple-negative breast cancer (TNBC) is a highly aggressive and invasive type of breast cancer. In addition, type 2 diabetes mellitus (T2DM) is recognized as a risk factor for cancer metastasis, which is associated with mortality in patients with breast cancer. Cancer-associated fibroblasts (CAFs) generated from adipose tissue-derived mesenchymal stem cells (AT-MSCs) play a vital role in the progression of TNBC. However, to date, whether T2DM affects the ability of AT-MSCs to differentiate into CAFs is still unclear. In this study, we found that in coculture with TNBC cells [breast cancer cells (BCCs)] under hypoxic conditions, AT-MSCs derived from T2DM donors (dAT-MSCs) were facilitated to differentiate into CAFs, which showed fibroblastic morphology and the induced expression of fibroblastic markers, such as fibroblast activation protein, fibroblast-specific protein, and vimentin. This was involved in the higher expression of transforming growth factor beta receptor 2 (TGFβR2) and the phosphorylation of Smad2/3. Furthermore, T2DM affected the fate and functions of CAFs derived from dAT-MSCs. While CAFs derived from AT-MSCs of healthy donors (AT-CAFs) exhibited the markers of inflammatory CAFs, those derived from dAT-MSCs (dAT-CAFs) showed the markers of myofibroblastic CAFs. Of note, in comparison with AT-CAFs, dAT-CAFs showed a higher ability to induce the proliferation and in vivo metastasis of BCCs, which was involved in the activation of the transforming growth factor beta (TGFβ)-Smad2/3 signaling pathway. Collectively, our study suggests that T2DM contributes to metastasis of BCCs by inducing the myofibroblastic CAFs differentiation of dAT-MSCs. In addition, targeting the TGFβ-Smad2/3 signaling pathway in dAT-MSCs may be useful in cancer therapy for TNBC patients with T2DM.

Topics: Breast Neoplasms; Cancer-Associated Fibroblasts; Cell Line, Tumor; Diabetes Mellitus, Type 2; Female; Fibroblasts; Humans; Mesenchymal Stem Cells; Transforming Growth Factor beta; Triple Negative Breast Neoplasms

Circulating proteins associated with transforming growth factor-β (TGF-β) signaling are implicated in the development of diabetic kidney disease (DKD). It remains to be comprehensively examined which of these proteins are involved in the pathogenesis of DKD and its progression to end-stage kidney disease (ESKD) in humans. Using the SOMAscan proteomic platform, we measured concentrations of 25 TGF-β signaling family proteins in four different cohorts composed in total of 754 Caucasian or Pima Indian individuals with type 1 or type 2 diabetes. Of these 25 circulating proteins, we identified neuroblastoma suppressor of tumorigenicity 1 (NBL1, aliases DAN and DAND1), a small secreted protein known to inhibit members of the bone morphogenic protein family, to be most strongly and independently associated with progression to ESKD during 10-year follow-up in all cohorts. The extent of damage to podocytes and other glomerular structures measured morphometrically in 105 research kidney biopsies correlated strongly with circulating NBL1 concentrations. Also, in vitro exposure to NBL1 induced apoptosis in podocytes. In conclusion, circulating NBL1 may be involved in the disease process underlying progression to ESKD, and its concentration in circulation may identify subjects with diabetes at increased risk of progression to ESKD.

Topics: Cell Cycle Proteins; Diabetes Mellitus, Type 2; Disease Progression; Humans; Kidney Failure, Chronic; Neuroblastoma; Proteomics; Transforming Growth Factor beta

Dapagliflozin, an inhibitor of sodium-glucose cotransporter 2 (SGLT2), is a new type of oral hypoglycemic drugs which can promote glucose excretion in the kidney. Studies have shown that dapagliflozin has renoprotective effect in the treatment of type 2 diabetes. However, the underlying mechanism remains unclear. Here, we combined integrated RNA sequencing and network pharmacology approach to investigate the molecular mechanism of dapagliflozin for diabetic nephropathy (DN). Dapagliflozin significantly relieved glucose intolerance, urinary albumin/creatinine ratio (UACR) and renal pathological injuries of db/db mice. The LncRNA and mRNA expression in kidney tissues from control group (CR), db/db group (DN) and dapagliflozin group (DG) were assessed by RNA sequencing. We identified 7 LncRNAs and 64 mRNAs common differentially expressed in CR vs DN and DN vs DG, which were used to construct co-expression network to reveal significantly correlated expression patterns in DN. In addition, network pharmacology was used to predict the therapeutic targets of dapagliflozin and we constructed component-target-pathway network according to the results of RNA sequencing and network pharmacology. We found that SMAD9, PPARG, CD36, CYP4A12A, CYP4A12B, CASP3, H2-DMB2, MAPK1, MAPK3, C3 and IL-10 might be the pivotal targets of dapagliflozin for treating DN and these genes were mainly enriched in pathways including TGF-β signaling pathway, PPAR signaling pathway, Chemokine signaling pathway, etc. Our results have important implication and provide novel insights into the protective mechanism of dapagliflozin for treating DN.

Topics: Albumins; Animals; Benzhydryl Compounds; Caspase 3; Chemokines; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucose; Glucosides; Interleukin-10; Mice; Network Pharmacology; PPAR gamma; RNA, Long Noncoding; RNA, Messenger; Sequence Analysis, RNA; Sodium; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Transforming Growth Factor beta

Type 2 diabetes (T2D) is a common chronic disease with many serious complications. Celastrol can prevent and treat type 2 diabetes by reversing insulin resistance in a number of ways. However, the specific mechanisms by which celastrol prevents and treats T2D are not well understood. The aim of this study was to explore the key gene targets and potential signaling pathway mechanisms of celastrol for the treatment of T2D.. GSE184050 was downloaded from the Gene Expression Omnibus online database. Blood samples from patients and healthy individuals with T2D were analyzed to identify differentially expressed genes (DEGs), and a protein-protein interaction network (PPI) was constructed. Key gene analysis of DEGs was performed using the MCODE plugin in Cystoscope as well as the Hubba plugin, and intersections were taken to obtain hub genes, which were displayed using a Venn diagram. Enrichment analysis was then performed. 618 DEGs were obtained, and 9 hub genes for T2D were identified by the MCODE and Hubba plug-ins, including ADAMTS15, ADAMTS7, ADAMTSL1, SEMA5B, ADAMTS8, THBS2, HBB, HBD and HBG2. The DEG-enriched signaling pathways mainly included the ferroptosis and TGF-beta signaling pathways. A total of 228 target genes were annotated by pharmacophore target analysis, and the therapeutic targets were identified, including S100A11, RBP3, HBB, BMP7 and IQUB, and 9 therapeutic signaling pathways were obtained by an intersectional set. The protein structures of the therapeutic targets were successfully predicted by AlphaFold2, and docking was validated using molecular docking.. Celastrol may prevent and treat T2D through key target genes, such as HBB, as well as signaling pathways, such as the TGF-beta signaling pathway and type II diabetes mellitus.

Topics: ADAMTS Proteins; Artificial Intelligence; Computational Biology; Diabetes Mellitus, Type 2; Gene Expression Profiling; Humans; Molecular Docking Simulation; Network Pharmacology; Transforming Growth Factor beta

The aim of this study was to evaluate changes in the serum levels of miR-98, miR-184, miR-185, miR-203 and miR-196a-3p in type 2 diabetes mellitus (T2DM) patients with diabetic nephropathy (DN) and to associate the changes in microRNA levels with urinary albumin excretion (UAE).. The study included 35 healthy individuals aged between 18-65 years, 40 T2DM patients with normoalbuminuria, 40 T2DM patients with microalbuminuria, and 35 T2DM patients with macroalbuminuria. Metabolic laboratory parameters, microalbumin levels in 24-hour urine samples were measured in all groups. Serum levels of vascular endothelial growth factor-A (VEGF-A) and transforming growth factor-β (TGF-β) were measured quantitatively by Enzyme-Linked Immunosorbent Assay (ELISA). Circulating miRNA levels were determined by real-time quantitative PCR.. Serum miR-196a-3p levels were reduced in the normoalbuminuria group compared to the healthy control group. In the macroalbuminuria and microalbuminuria groups, miR-196a-3p levels were higher compared to the normoalbuminuria group. In addition, increase in miR-196a-3p levels in the macroalbuminuria group was more prominent than the microalbuminuria group. Serum miR-203 levels were significantly higher in the macroalbuminuria group compared to healthy controls, microalbuminuria and normoalbuminuria groups; these levels were also higher in the microalbuminuria group compared to normoalbuminuria group. In logistic regression analysis, serum miR-196a-3p and miRNA-203 levels were independently correlated to UAE.. Increased serum levels of miR-203 and miR-196a-3p are independent risk factors of UAE which is a marker of DN.

Topics: Adolescent; Adult; Aged; Albumins; Albuminuria; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; MicroRNAs; Middle Aged; Risk Factors; Transforming Growth Factor beta; Transforming Growth Factors; Vascular Endothelial Growth Factor A; Young Adult

Extracellular vesicles (EVs) have been recently postulated as key players in metabolic disorders emerging as an alternative way of paracrine/endocrine communication. However, the nature of EVs shed by adipose tissue (AT) and their role in obesity is still very limited. Here, we isolated human morbid obese visceral (VAT) and subcutaneous (SAT) whole AT shed EVs from donors submitted to bariatric surgery to characterize their protein cargo by qualitative and quantitative/SWATH mass spectrometry analysis. We identified 574 different proteins shed by morbid obese VAT and 401 proteins in those from SAT, establishing the first obese AT EV proteome reference map. Only 50% of identified proteins in VAT vesicles were common to those in SAT; additionally, EVs shed by obese VAT showed more AT and obesity-related adipokines than SAT. Functional classification shows that obese VAT vesicles exhibit an enrichment of proteins implicated in AT inflammation and insulin resistance such as TGFBI, CAVN1, CD14, mimecan, thrombospondin-1, FABP-4 or AHNAK. Selected candidate biomarkers from the quantitative-SWATH analysis were validated in EVs from independent morbid obese and from moderate obese to lean individuals showing that morbid obese VAT vesicles are characterized by a diminution of syntenin 1 and the elevation of TGFBI and mimecan. Interestingly, TGFBI and mimecan containing vesicles could be detected and quantified at circulating level in plasma. Thus, a significant elevation of -TGFBI-EVs was detected on those obese patients with a history of T2D compared to nondiabetic, and an augmentation of mimecan-EVs in obese plasma compared to those in healthy lean individuals. Thus, we conclude that obese AT release functional EVs carrying AT and obesity candidate biomarkers which vary regarding the AT of origin. Our findings suggest that circulating EV-TGFBI may facilitate monitoring T2D status in obese patients, and EV-mimecan may be useful to track adiposity, and more precisely, visceral obesity.

Topics: Adipose Tissue, White; Adult; Biomarkers; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Extracellular Vesicles; Female; Humans; Intercellular Signaling Peptides and Proteins; Intra-Abdominal Fat; Male; Middle Aged; Obesity; Obesity, Morbid; Proteins; Subcutaneous Fat; Syntenins; Transforming Growth Factor beta

Anti-inflammatory cytokines act as double edged swords- they can dampen inflammation but can also suppress immunity. The role played by these cytokines in latent TB infected (LTBI) subjects, with various grades of glucose intolerance was studied. Both serum levels and recall-secretion of IL-27, IL-10, IL-1Ra and TGF-β in Normal Glucose Tolerance (NGT), Pre-Diabetes (PDM), Newly diagnosed Diabetes (NDM) and Known Diabetes (KDM) subjects, both with and without LTBI (n = 382), were quantified by ELISA. All the subjects were screened for LTBI by QuantiFERON-TB Gold test. Serum levels of IL-27, IL-10 and IL-1Ra were significantly elevated in the LTB

Topics: Adult; Cholesterol; Cytokines; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Glucose Intolerance; Humans; Inflammation Mediators; Interleukin 1 Receptor Antagonist Protein; Interleukin-10; Interleukin-27; Latent Tuberculosis; Middle Aged; Reproducibility of Results; Sensitivity and Specificity; Transforming Growth Factor beta

Topics: Adipocytes; Animals; CD52 Antigen; Cell Differentiation; Cells, Cultured; Datasets as Topic; Diabetes Mellitus, Type 2; Diet, High-Fat; Gene Expression Profiling; Gene Regulatory Networks; Genetic Predisposition to Disease; Humans; Intra-Abdominal Fat; Lymphocyte Activation; Mice; Mice, Knockout; Obesity; Primary Cell Culture; Prospective Studies; Protein Interaction Maps; Signal Transduction; Smad3 Protein; T-Lymphocytes; Transforming Growth Factor beta; Up-Regulation

Diabetic nephropathy, a major threat to diabetic patients, is considered as the main reason for end-stage renal disease. Fortunately, incretin-based therapy has been aroused as considerable source to attenuate diabetic renal damage. This study aimed to investigate whether superior protective effects on the progression of diabetic kidney are exerted by glucagon-like peptide-1 analog, exenatide, or dipeptidyl peptidase-4 inhibitor, sitagliptin.. Male Wistar rats were fed high-fat diet for 2 weeks followed by injection of low dose streptozotocin to induce type 2 diabetes mellitus. Four weeks after induction of diabetes, diabetic rats were administered vehicle, exenatide (5 μg/kg/day, SC) or sitagliptin (10 mg/kg/day, orally) for 4 weeks.. Different incretin mimetic agents improved renal function as evident by significant decreases in serum creatinine and urea levels with decline in urinary microalbuminuria and marked improvement in histological alterations. Both treated diabetic rats also exhibited a significant improvement in metabolic intolerance with more pronounced effect of exenatide on glucose regulation. Ameliorated renal oxidative stress alongside significant downregulation in transforming growth factor-beta, tumor necrosis factor-alpha and cleaved-caspase-3 protein expressions in renal tissues were recorded in treated diabetic rats.. Administration of either exenatide or sitagliptin showed ameliorative effects on early diabetic nephropathy without notable differences between their renal protective effects. However, further clinical studies are still required to ensure their comparative promising effects on the management of renal complication of diabetes.

Topics: Animals; Caspase 3; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Gene Expression Regulation; Incretins; Male; Rats; Rats, Wistar; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Vitamin D and rosuvastatin are well-known drugs that mediate beneficial effects in treating type-2 diabetes (T2D) complications; however, their anti-neuropathic potential is debatable. Hence, our study investigates their neurotherapeutic potential and the possible underlying mechanisms using a T2D-associated neuropathy rat model.. Diabetic peripheral neuropathy (DPN) was induced with 8 weeks of administration of a high fat fructose diet followed by a single i.p. injection of streptozotocin (35 mg/kg). Six weeks later, DPN developed and rats were divided into five groups; viz., control, untreated DPN, DPN treated with vitamin D (cholecalciferol, 3500 IU/kg/week), DPN treated with rosuvastatin (10 mg/kg/day), or DPN treated with combination vitamin D and rosuvastatin. We determined their anti-neuropathic effects on small nerves (tail flick test); large nerves (electrophysiological and histological examination); neuronal inflammation (TNF-α and IL-18); apoptosis (caspase-3 activity and Bcl-2); mitochondrial function (NRF-1, TFAM, mtDNA, and ATP); and NICD1, Wnt-10α/β-catenin, and TGF-β/Smad-7 pathways.. Two-month treatment with vitamin D and/or rosuvastatin regenerated neuronal function and architecture and abated neuronal inflammation and apoptosis. This was verified by the inhibition of the neuronal content of TNF-α, IL-18, and caspase-3 activity, while augmenting Bcl-2 content in the sciatic nerve. These treatments inhibited the protein expressions of NICD1, Wnt-10α, β-catenin, and TGF-β; increased the sciatic nerve content of Smad-7; and enhanced mitochondrial biogenesis and function.. Vitamin D and/or rosuvastatin alleviated diabetes-induced neuropathy by suppressing Notch1 and Wnt-10α/β-catenin; modulating TGF-β/Smad-7 signaling pathways; and enhancing mitochondrial function, which lessened neuronal degeneration, demyelination, and fibrosis.

Topics: Animals; Anticholesteremic Agents; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Drug Therapy, Combination; Gene Expression Regulation; Male; NF-E2-Related Factor 1; Rats; Rats, Wistar; Receptor, Notch1; Rosuvastatin Calcium; Transforming Growth Factor beta; Vitamin D; Vitamins; Wnt Proteins

Diabetic cardiomyopathy (DCM) is one of the leading causes of heart failure in patients with diabetes mellitus, with limited effective treatments. The cardioprotective effects of sodium-glucose cotransporter 2(SGLT2) inhibitors have been supported by amounts of clinical trials, which largely fills the gap. However, the underlying mechanism still needs to be further explored, especially in terms of its protection against cardiac fibrosis, a crucial pathophysiological process during the development of DCM. Besides, endothelial-to-mesenchymal transition (EndMT) has been reported to play a pivotal role in fibroblast multiplication and cardiac fibrosis. This study aimed to evaluate the effect of SGLT2 inhibitor dapagliflozin (DAPA) on DCM especially for cardiac fibrosis and explore the underlying mechanism. In vivo, the model of type 2 diabetic rats was built with high-fat feeding and streptozotocin injection. Untreated diabetic rats showed cardiac dysfunction, increased myocardial fibrosis and EndMT, which was attenuated after treatment with DAPA and metformin. In vitro, HUVECs and primary cardiac fibroblasts were treated with DAPA and exposed to high glucose (HG). HG-induced EndMT in HUVECs and collagen secretion of fibroblasts were markedly inhibited by DAPA. Up-regulation of TGF-β/Smad signalling and activity inhibition of AMPKα were also reversed by DAPA treatment. Then, AMPKα siRNA and compound C abrogated the anti-EndMT effects of DAPA in HUVECs. From above all, our study implied that DAPA can protect against DCM and myocardial fibrosis through suppressing fibroblast activation and EndMT via AMPKα-mediated inhibition of TGF-β/Smad signalling.

Topics: AMP-Activated Protein Kinases; Animals; Benzhydryl Compounds; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Diet, High-Fat; Disease Models, Animal; Epithelial-Mesenchymal Transition; Fibroblasts; Fibrosis; Glucosides; Male; Mesoderm; Rats; Signal Transduction; Smad4 Protein; Sodium-Glucose Transporter 2 Inhibitors; Transforming Growth Factor beta

Serum-derived extracellular vesicles (sEV) from healthy donors display in-vivo pro-angiogenic properties. To identify patients that may benefit from autologous sEV administration for pro-angiogenic purposes, sEV angiogenic capability has been evaluated in type 2 diabetic (T2DM) subjects (D), in obese individuals with (OD) and without (O) T2DM, and in subjects with ischemic disease (IC) (9 patients/group). sEV display different angiogenic properties in such cluster of individuals. miRNomic profile and TGFβ content in sEV were evaluated. We found that miR-130a and TGFβ content correlates with sEV in-vitro and in-vivo angiogenic properties, particularly in T2DM patients. Ingenuity Pathway Analysis (IPA) identified a number of genes as among the most significant miR-130a interactors. Gain-of-function experiments recognized homeoboxA5 (HOXA5) as a miR-130a specific target. Finally, ROC curve analyses revealed that sEV ineffectiveness could be predicted (Likelihood Ratio+ (LH+) = 3.3 IC 95% from 2.6 to 3.9) by comparing miR-130a and TGFβ content 'in Series'. We demonstrate that sEV from high cardiovascular risk patients have different angiogenic properties and that miR-130a and TGFβ sEV content predicts 'true ineffective sEVs'. These results provide the rationale for the use of these assays to identify patients that may benefit from autologous sEV administration to boost the angiogenetic process.

Topics: 3' Untranslated Regions; Adult; Aged; Cardiovascular Diseases; Case-Control Studies; Diabetes Mellitus, Type 2; Extracellular Vesicles; Female; Homeodomain Proteins; Humans; Male; MicroRNAs; Middle Aged; Transforming Growth Factor beta

β Cell apoptosis and dedifferentiation are 2 hotly debated mechanisms underlying β cell loss in type 2 diabetes; however, the molecular drivers underlying such events remain largely unclear. Here, we performed a side-by-side comparison of mice carrying β cell-specific deletion of ER-associated degradation (ERAD) and autophagy. We reported that, while autophagy was necessary for β cell survival, the highly conserved Sel1L-Hrd1 ERAD protein complex was required for the maintenance of β cell maturation and identity. Using single-cell RNA-Seq, we demonstrated that Sel1L deficiency was not associated with β cell loss, but rather loss of β cell identity. Sel1L-Hrd1 ERAD controlled β cell identity via TGF-β signaling, in part by mediating the degradation of TGF-β receptor 1. Inhibition of TGF-β signaling in Sel1L-deficient β cells augmented the expression of β cell maturation markers and increased the total insulin content. Our data revealed distinct pathogenic effects of 2 major proteolytic pathways in β cells, providing a framework for therapies targeting distinct mechanisms of protein quality control.

Topics: Adult; Aged; Animals; Cell Survival; Diabetes Mellitus, Type 2; Endoplasmic Reticulum; Female; HEK293 Cells; Humans; Insulin-Secreting Cells; Intracellular Signaling Peptides and Proteins; Male; Mice; Mice, Transgenic; Middle Aged; Proteins; Proteolysis; Receptor, Transforming Growth Factor-beta Type I; Signal Transduction; Transforming Growth Factor beta; Ubiquitin-Protein Ligases

Diabetes mellitus is a serious metabolic condition associated with a multitude of cardiovascular complications. Moreover, the prevalence of diabetes in heart failure populations is higher than that in control populations. However, the role of cardiomyocyte alterations in type 2 diabetes mellitus (T2DM) has not been well characterized and the underlying mechanisms remain elusive. In this study, two patients who were diagnosed as T2DM were recruited and patient-specific induced pluripotent stem cells (iPSCs) were generated from urine epithelial cells using nonintegrated Sendai virus. The iPSC lines derived from five healthy subjects were used as controls. All iPSCs were differentiated into cardiomyocytes (iPSC-CMs) using the monolayer-based differentiation protocol. T2DM iPSC-CMs exhibited various disease phenotypes, including cellular hypertrophy and lipid accumulation. Moreover, T2DM iPSC-CMs exhibited higher susceptibility to high-glucose/high-lipid challenge than control iPSC-CMs, manifesting an increase in apoptosis. RNA-Sequencing analysis revealed a differential transcriptome profile and abnormal activation of TGFβ signaling pathway in T2DM iPSC-CMs. We went on to show that inhibition of TGFβ significantly rescued the hypertrophic phenotype in T2DM iPSC-CMs. In conclusion, we demonstrate that the iPSC-CM model is able to recapitulate cellular phenotype of T2DM. Our results indicate that iPSC-CMs can therefore serve as a suitable model for investigating molecular mechanisms underlying diabetic cardiomyopathies and for screening therapeutic drugs.

Topics: Apoptosis; Arrhythmias, Cardiac; Biomarkers; Case-Control Studies; Cell Differentiation; Cells, Cultured; Diabetes Mellitus, Type 2; Epithelial Cells; Glucose; Humans; Immunophenotyping; Induced Pluripotent Stem Cells; Lipid Metabolism; Myocytes, Cardiac; Signal Transduction; Transcriptome; Transforming Growth Factor beta

Continuous feeding of high dietary sugar is strongly associated with type 2 diabetes (T2D) and its secondary complications. Diabetic nephropathy (DN) is a major secondary complication that leads to glomerular and renal tubular dysfunction. The present study is aimed to investigate the effects of chronic exposure of high sugar diet (HSD) on renal tubules. Malpighian tubules (MTs), a renal organ of Drosophila, were used as a model in the study. Feeding of HSD develops T2D condition in Drosophila. The MTs showed structural abnormalities in 20 days of HSD fed flies. Impaired insulin signaling, oxidative stress, enhanced levels of AGE-RAGE and induction of apoptosis were observed in the MTs of these flies. Further, altered expression of transporters, enhanced uric acid level and reduced fluid secretion rate confirmed the impaired function of MTs in these flies. RNA-seq and RT-PCR analyses in the MTs of HSD fed-and control-flies revealed the altered expression of candidate genes that regulate several important pathways including extracellular matrix (ECM), advanced glycation end products-receptor for advanced glycation end products (AGE-RAGE), transforming growth factor β (TGF-β), galactose, starch and sucrose metabolism that are well known mediators of renal tubular dysfunction in DN patients. Disruption of insulin signaling in the MTs also causes renal tubular dysfunction similar to HSD fed flies. Overall, the study suggests that phenotypes observed in the MTs of HSD fed flies recapitulate several hallmarks of renal tubular dysfunction in DN patients. Therefore, we conclude that MTs of HSD fed flies may be used for deciphering the underlying mechanisms of T2D mediated renal tubular dysfunction.

Topics: Animals; Apoptosis; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dietary Sucrose; Disease Models, Animal; Drosophila melanogaster; Glycation End Products, Advanced; Insulin; Malpighian Tubules; Oxidative Stress; Signal Transduction; Transforming Growth Factor beta

Renal fibrosis is a characteristic of diabetic nephropathy, which is a serious complication of diabetes. It has been reported that (-)-epigallocatechin gallate (EGCG) attenuates renal fibrosis. However, the molecular mechanism of regulation by EGCG in this process remains unclear. Previous studies showed that abnormal activation of Notch signaling contributes to the development of renal fibrosis. Previous studies have demonstrated that EGCG attenuates Notch1 expression. In this study, we found that the levels of fibronectin and Notch1 expression were decreased in human embryonic kidney cells after treatment with EGCG. We also observed that the type II transforming growth factor beta receptor (TGFβRII) and Smad3 pathway were inhibited in kidney cells by treatment with EGCG. In the diabetic kidney, we found that the activation of Notch signaling was attenuated by administration of EGCG. Moreover, TGFβRII and Smad3 phosphorylation could be inhibited by treatment with EGCG in the kidney. These results indicated that EGCG may improve renal fibrosis by targeting Notch via inhibition of the TGFβ/Smad3 pathway in diabetic mice. Our findings provide insight into the therapeutic strategy for diabetes-induced renal fibrosis, and suggest EGCG to be a novel potential medicine for the treatment of chronic kidney disease in patients with diabetes.

Topics: Animals; Antioxidants; Catechin; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Female; Injections, Intraperitoneal; Mice; Mice, Inbred ICR; Random Allocation; Renal Insufficiency, Chronic; Signal Transduction; Smad3 Protein; Streptozocin; Transforming Growth Factor beta

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

Pro-inflammatory biomarkers are well-established contributors to insulin resistance and represent valid targets for diabetes management and prevention. Yet, little is known whether nutrition could play a role in modulating various aspects of immune-inflammatory responses. Our aim is to assess the effect of isocaloric animal and plant protein dietary interventions on selected biomarkers representing various immune-inflammatory pathways.. We enrolled 37 participants with type 2 diabetes (age 64 ± 6 years, body mass index 30.2 ± 3.6 kg/m. Chemerin and progranulin concentrations decreased following AP and PP diets. TGF-β1 increased in AP and decreased in PP, whereas calprotectin increased in PP and decreased in AP. No statistically significant differences in the concentrations of IL-6, TNF-α, suPAR, lactoferrin and GDF-15 could be seen in either of the protein diet arms.. These results suggest that both AP and PP diets may effectively reduce the levels of the pro-inflammatory adipokines chemerin and progranulin. The effects on the additional immune-inflammatory biomarkers seem to be more complex.. NCT02402985 (ww.clinicaltrials.gov).

Topics: Adipokines; Aged; Animal Proteins, Dietary; Biomarkers; Diabetes Mellitus, Type 2; Diet, High-Protein; Female; Humans; Inflammation; Leukocyte L1 Antigen Complex; Male; Middle Aged; Plant Proteins, Dietary; Transforming Growth Factor beta

Obesity increases the risk of diabetes mellitus (DM) and hypertension. We aimed to analyze the serum levels of cytokines that have relevance to the pathologies including, interleukin-4 (IL-4), transforming growth factor-β (TGF-β), interferon-γ (IFN-γ), and IL-6 cytokines of overweight men with DM and/or hypertension.. The study collected serum from 164 men. The sample population contained, 54 overweight men without DM or hypertension (control [CTL] group), 36 men with both DM and hypertension (DH group), 20 men with DM but no hypertension (D group), and 54 had hypertension without DM (H).. The main results showed that the concentration of IFN-γ in the DH group was significantly higher than the D, H, and CTL groups, IL-6 in DH and D groups was significantly lower than the CTL group. The serum level of TGF-β and IL-4 cytokines did not show any significant differences across the four groups. Serum levels of IL-6 were also significantly lower in untreated patients in D group than controls and in DH when compared with H groups.. In conclusion, it appears that the proinflammatory and anti-inflammatory cytokines either play a significant role in the pathogenesis of hypertension and DM or serve as markers for these pathologies. Accordingly, increased serum levels of IFN-γ may participate in the pathogenesis of hypertension in the diabetic patients and decreased IL-6 is associated with type 2 DM.

Topics: Antihypertensive Agents; Diabetes Mellitus, Type 2; Humans; Hypertension; Hypoglycemic Agents; Interferon-gamma; Interleukin-4; Interleukin-6; Male; Middle Aged; Obesity; Transforming Growth Factor beta

Visceral obesity is associated with insulin resistance and higher risk of type 2 diabetes and metabolic diseases. A limited ability of adipose tissues to remodel through the recruitment and differentiation of adipose stem cells (ASCs) is associated with adipose tissue inflammation and fibrosis and the metabolic syndrome. We show that the lower adipogenesis of omental (Om) compared with abdominal subcutaneous (Abdsc) ASCs was associated with greater secretion of TGFβ ligands that acted in an autocrine/paracrine loop to activate SMAD2 and suppress adipogenesis. Inhibition of TGFβ signaling rescued Om ASC differentiation. In Abdsc ASCs, low concentrations of dexamethasone suppressed TGFβ signaling and enhanced adipogenesis, at least in part by increasing TGFBR3 protein that can sequester TGFβ ligands. Om ASCs were resistant to these dexamethasone effects; recombinant TGFBR3 increased their differentiation. Pericellular fibrosis, a hallmark of dysfunctional adipose tissue, was greater in Om and correlated with higher level of tissue TGFβ signaling activity and lower ASC differentiation. We conclude that glucocorticoids restrain cell-autonomous TGFβ signaling in ASCs to facilitate adipogenesis and healthy remodeling in Abdsc and these processes are impaired in Om. Therapies directed at overcoming glucocorticoid resistance in visceral adipose tissue may improve remodeling and help prevent metabolic complications of visceral obesity.

Topics: Activins; Adipogenesis; Adipose Tissue; Adult; Dexamethasone; Diabetes Mellitus, Type 2; Female; Fibrosis; Glucocorticoids; Humans; Interleukin-6; Male; Middle Aged; Omentum; Proteoglycans; Receptors, Transforming Growth Factor beta; Stem Cells; Transforming Growth Factor beta; Young Adult

Small-molecule inhibitors of dual-specificity tyrosine-regulated kinase 1A (DYRK1A) induce human beta cells to proliferate, generating a labeling index of 1.5%-3%. Here, we demonstrate that combined pharmacologic inhibition of DYRK1A and transforming growth factor beta superfamily (TGFβSF)/SMAD signaling generates remarkable further synergistic increases in human beta cell proliferation (average labeling index, 5%-8%, and as high as 15%-18%), and increases in both mouse and human beta cell numbers. This synergy reflects activation of cyclins and cdks by DYRK1A inhibition, accompanied by simultaneous reductions in key cell-cycle inhibitors (CDKN1C and CDKN1A). The latter results from interference with the basal Trithorax- and SMAD-mediated transactivation of CDKN1C and CDKN1A. Notably, combined DYRK1A and TGFβ inhibition allows preservation of beta cell differentiated function. These beneficial effects extend from normal human beta cells and stem cell-derived human beta cells to those from people with type 2 diabetes, and occur both in vitro and in vivo.

Topics: Adolescent; Adult; Aged; Animals; Cell Line; Cell Proliferation; Diabetes Mellitus, Type 2; Dyrk Kinases; Female; Harmine; Histone-Lysine N-Methyltransferase; Humans; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Middle Aged; Monoamine Oxidase Inhibitors; Myeloid-Lymphoid Leukemia Protein; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Smad Proteins; Stem Cells; Transforming Growth Factor beta; Young Adult

Mulberry leaf is one of the commonly used traditional Chinese medicines, has been shown to exert hypoglycemic effects against diabetes. The aim of this study is to investigate the effects and mechanism of mulberry leaf flavonoids (MF), polysaccharides (MP) and alkaloids (MA) on diabetic and its liver and kidney injury. The db/db mice was adopted and the results showed that the FBG (fasting blood glucose) of model group continued to increase and associated liver and kidney injury. After the intervention of MP and MA, the value of FBG exhibited the most obvious hypoglycemic effect. MF and MP have obvious improved effect on kidney injury, which reduced the content of mALB/Cre (microalbumin/creatinine) in urine and improved the tubular epithelial cells edematous and renal cystic epithelial thickening. While the MF and MA possessed a significant effect on liver damage, manifested in reducing the levels of ALT (alanine aminotransferase) and AST (aspartate aminotransferase) and pathological changes of liver on db/db mice. Through metabolomics analysis, 13 endogenous potential biomarkers were identified in serum. The three effective components of mulberry can regulate the 13 potential biomarkers and the corresponding metabolic pathway. Collectively, the components of mulberry leaf have clear hypoglycemic effect and protective effect on liver and kidney injury and the effects are related to insulin receptor and TGF-β/Smads signaling pathway.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Kidney; Liver; Male; Mice; Mice, Transgenic; Morus; Plant Extracts; Plant Leaves; Receptor, Insulin; Signal Transduction; Transforming Growth Factor beta

We analyzed expression of LRG1 mRNA in glomeruli of diabetic kidneys and assessed its localization by RNA. LRG1 localized predominantly to glomerular endothelial cells, and its expression was elevated in the diabetic kidneys. LRG1 ablation markedly attenuated diabetes-induced glomerular angiogenesis, podocyte loss, and the development of diabetic glomerulopathy. These improvements were associated with reduced ALK1-Smad1/5/8 activation in glomeruli of diabetic mice. Moreover, increased plasma LRG1 was associated with worse renal outcome in patients with type 2 diabetes.. These findings identify LRG1 as a potential novel pathogenic mediator of diabetic glomerular neoangiogenesis and a risk factor in DKD progression.

Topics: Activin Receptors, Type II; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Endothelial Cells; Female; Gene Knockdown Techniques; Glomerular Filtration Rate; Glycoproteins; Humans; Kidney Failure, Chronic; Kidney Glomerulus; Male; Middle Aged; Neovascularization, Pathologic; Podocytes; RNA, Messenger; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

Chemerin is an adipocytokine that participates in glycolipid metabolism; however, its association with type 2 diabetes (T2DM) with lower extremity macroangiopathy (T2DM-V) has rarely been reported. This study explored the association of chemerin and inflammatory factors with body fat parameters, glucolipid metabolism, and insulin resistance (IR) in T2DM and T2DM-V. Patients were classified into normal glucose regulation (NGR), T2DM, and T2DM-V groups. Serum chemerin, glucolipid metabolic parameters, transforming growth factor (TGF)-β, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, and fasting insulin levels were measured along with HOMA-IR, body mass index (BMI), and waist-to-stature ratio (WSR). Serum chemerin, TGF-β, IL-6, and MCP-1 levels were significantly higher in T2DM groups than in NGR group, and BMI, WSR, fasting plasma glucose (FPG), 2hPG, glycated hemoglobin (HbA1c), triglycerides (TG), and HOMA-IR were higher in T2DM-V subgroups with moderate or severe lower extremity macroangiopathy than in NGR group, simple T2DM group, and T2DM-V subgroup with mild macroangiopathy. FPG, 2hPG, HbA1c, TG, and HOMA-IR were higher in T2DM-V subgroup with severe macroangiopathy than in T2DM-V with moderate macroangiopathy (p < 0.05). In all groups, serum chemerin levels were positively correlated with BMI, WSR, FPG, 2hPG, HbA1c, fasting insulin, aspartate transaminase, TG, TGF-β, IL-6, and HOMA-IR (p < 0.05) and negatively correlated with high-density lipoprotein cholesterol [HDL-c] (p < 0.05). Multiple stepwise regression analysis showed that 2hPG, HbA1c, and HDL-c were independent predictors of serum chemerin levels (β = -0.768, -0.122, -0.115, and 3.261, respectively; p < 0.01). Collectively, chemerin, factors associated with obesity, pathological and physiological changes in glucolipid metabolism, and inflammatory factors may promote the development of T2DM macroangiopathy.

Topics: Adult; Aged; Blood Glucose; Body Height; Body Mass Index; Chemokine CCL2; Chemokines; Cholesterol, HDL; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Glucose Tolerance Test; Glycated Hemoglobin; Glycolipids; Humans; Inflammation; Insulin; Insulin Resistance; Interleukin-6; Male; Middle Aged; Obesity; Regression Analysis; Transforming Growth Factor beta; Triglycerides; Waist-Height Ratio

The regional injection of connective tissue growth factor (CTGF) for diabetic wound healing requires multiple components and results in a substantial loss of its biological activity. Acellular dermal matrix (ADM) scaffolds are optimal candidates for delivering these factors to local ischaemic environments. In this study, we explored whether CTGF loaded on ADM scaffolds can enhance fibronectin (FN) expression to accelerate diabetic wound healing via the protein kinase C (PKC) signalling pathway. The performance of CTGF and CTGF + PKC inhibitor, which were loaded on ADM scaffolds to treat dorsal skin wounds in streptozotocin-induced diabetic mice, was evaluated with naked ADM as a control. Wound closure showed that ADM scaffolds loaded with CTGF induced greater diabetic wound healing in the early stage of the wound in diabetic mice. Moreover, ADM scaffolds loaded with CTGF obviously increased the expression of FN both at the mRNA and protein levels, whereas the expression of FN was significantly reduced in the inhibitor group. Furthermore, the ADM + CTGF group, which produce FN, obviously promoted alpha-smooth muscle actin and transforming growth factor-beta expression and enhanced neovasculature and collagen synthesis at the wound sites. ADM scaffolds loaded with CTGF + PKC inhibitor delayed diabetic wound healing, indicating that FN expression was mediated by the PKC signalling pathway. Our findings offer new perspectives for the treatment of diabetic wound healing and suggest a rationale for the clinical evaluation of CTGF use in diabetic wound healing.

Topics: Acellular Dermis; Animals; Coated Materials, Biocompatible; Collagen; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Fibronectins; Humans; Male; Mice, Inbred ICR; Microvessels; Protein Kinase C; RNA, Messenger; Signal Transduction; Tissue Scaffolds; Transforming Growth Factor beta; Wound Healing

Recent studies have shown that dysfunction and decrease of regulatory T cells (Tregs) correlates with insulin resistance (IR), one of the most significant mechanisms for type 2 diabetes mellitus (T2DM). To examine potential relationships among Tregs, IR, blood lipid content, and related cytokines, we investigated the frequency of CD4+CD25+Foxp3+ Tregs, as well as expression levels of interleukin 10 (IL-10) and transforming growth factor-β (TGF-β) in newly diagnosed T2DM patients.. Fifty-one newly diagnosed T2DM patients and 55 control individuals were enrolled. According to body mass index (BMI), the T2DM patients were grouped into non-obese and obese groups. Blood was collected in ethylene diamine tetraacetic acid (EDTA) anticoagulant tubes for detection of CD4+CD25+Foxp3+ Tregs by flow cytometry. Serum was collected to quantify IL-10 and TGF-β levels by enzyme-linked immunosorbent assay (ELISA). By comparing percentages of Tregs between non-obese and obese groups, correlation with Treg frequency, homeostasis model assessment of insulin resistance (HOMA-IR), IL-10 and TGF-β was examined.. The percentage of CD4+CD25+Foxp3+ Tregs in the newly diagnosed T2DM group was significantly lower than in the control group (P<0.01). Further, levels of IL-10 and TGF-β were also lower in the T2DM group (P<0.05). The level of IL-10 was remarkably lower in the obese group than in the non-obese and the control groups (P<0.01), but there was no significant difference between non-obese group and the control group. The level of TGF-β was lower in obese group than in the control group (P<0.05). There was no significant difference between non-obese group and the control group. The frequency of CD4+CD25+Foxp3+ Tregs in the obese group was significantly lower than in the non-obese group (P<0.05). In the obese group, the percentage of Tregs negatively correlated with HOMA-IR and positively correlated with TGF-β (P<0.05). There was no obvious correlation between Treg and HOMA-IR in the non-obese group.. The percentage of CD4+CD25+Foxp3+ Tregs and levels of related cytokines IL-10 and TGF-β were precipitously decreased in newly diagnosed T2DM patients. Therefore, the function of Tregs in limiting the proinflammatory milieu represents an important pathogenic mediator of the development of obesity-induced IR in newly diagnosed T2DM patients. Notably, TGF-β may play an important role in this process. Thus, enhancing expression of Tregs may improve IR in newly diagnosed T2DM patients with obesity.

Topics: Adult; Body Mass Index; Diabetes Mellitus, Type 2; Female; Forkhead Transcription Factors; Humans; Insulin Resistance; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Male; Middle Aged; Obesity; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

There is some controversy as for the roles played by tumor growth factor-β (TGF-β), interleukin-1β (IL-1β), and IL-22 in the onset process of type 2 diabetes (T2D). The main aim of this project was to examine serum levels of TGF-β, IL-1β, and IL-22 in the new cases and long period T2D patients as well as healthy controls. In this study, 115 new T2D patient cases (group 1), 434 T2D patients who have suffered from the disease more than 2 years (group 2), and 104 healthy controls have been selected from 6240 (3619 females) patients who were under study population from Kerman Coronary Artery Disease Risk Factor Study. Serum levels of TGF-β, IL-1β, and IL-22 have been evaluated using commercial kits. Serum levels of TGF-β and IL-1β significantly increased, while IL-22 decreased in 2 groups in comparison to healthy controls. Serum levels of IL-22, but not TGF-β and IL-1β, were significantly decreased in group 1 in comparison to healthy controls. There were no significant differences between groups 1 and 2 as for the cytokine levels. Serum levels of IL-22 increased in the females in group 2 when compared to females in group 1. It appears that TGF-β and IL-1β participate in the induction of inflammation after establishment of T2D, while decrease in IL-22 may be considered as a key factor for onset of the disease. Gender can also be considered as the main risk factor for variation in cytokine levels.

Topics: Blood Pressure; Diabetes Mellitus, Type 2; Female; Humans; Interleukin-1beta; Interleukin-22; Interleukins; Male; Risk Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Advanced glycation end products (AGEs) play a causative role in the development of diabetic nephropathy via induction of matrix protein deposition in kidneys. This study investigated inhibitory effects of chrysin, present in bee propolis and herbs, on glomerulosclerosis in db/db mice and AGEs-exposed renal mesangial cells. The in vivo study explored the demoting effects of 10 mg/kg chrysin on glomerular fibrosis in a type 2 diabetic model. Oral supplementation of chrysin inhibited the collagen fiber accumulation and α-smooth muscle actin (α-SMA) induction in periodic acid schiff-positive renal tissues of db/db mice. Moreover, treating db/db mice with chrysin diminished the level of AGEs increased in diabetic glomeruli. The in vitro study employed human mesangial cells exposed to 100 μg/mL AGE-BSA for 72 h in the presence of 1⁻20 μM chrysin. Glucose increased mesangial AGE production via induction of receptor for AGEs. Chrysin suppressed the induction of collagens, α-SMA, fibroblast-specific protein-1 and matrix metalloproteinases enhanced by AGE-bovine serum albumin. Furthermore, chrysin blunted transforming growth factor-β1 induction and Smad 2/3 activation in AGEs-exposed mesangial cells. These results demonstrate that chrysin attenuated accumulation of myofibroblast-like cells and matrix proteins in AGEs-laden diabetic glomeruli. Therefore, chrysin may be a potential renoprotective agent targeting glucose-mediated AGEs-associated glomerulosclerosis and fibrosis.

Topics: Animals; Blood Glucose; Cells, Cultured; Cytoprotection; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Dose-Response Relationship, Drug; Extracellular Matrix; Fibrosis; Flavonoids; Glucose; Glycation End Products, Advanced; Humans; Mesangial Cells; Mice, Inbred C57BL; Receptor for Advanced Glycation End Products; Serum Albumin, Bovine; Signal Transduction; Smad Proteins, Receptor-Regulated; Transforming Growth Factor beta

Growth differentiation factor 11 (GDF11) has been implicated in the regulation of islet development and a variety of aging conditions, but little is known about the physiological functions of GDF11 in adult pancreatic islets. Here, we showed that systematic replenishment of GDF11 not only preserved insulin secretion but also improved the survival and morphology of β-cells and improved glucose metabolism in both nongenetic and genetic mouse models of type 2 diabetes (T2D). Conversely, anti-GDF11 monoclonal antibody treatment caused β-cell failure and lethal T2D. In vitro treatment of isolated murine islets and MIN6 cells with recombinant GDF11 attenuated glucotoxicity-induced β-cell dysfunction and apoptosis. Mechanistically, the GDF11-mediated protective effects could be attributed to the activation of transforming growth factor-β/Smad2 and phosphatidylinositol-4,5-bisphosphate 3-kinase-AKT-FoxO1 signaling. These findings suggest that GDF11 repletion may improve β-cell function and mass and thus may lead to a new therapeutic approach for T2D.

Topics: Animals; Antibodies, Monoclonal; Apoptosis; Blood Glucose; Blotting, Western; Bone Morphogenetic Proteins; Cell Line; Cell Survival; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Forkhead Box Protein O1; Glucose Tolerance Test; Growth Differentiation Factors; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Mice; Phosphotransferases (Alcohol Group Acceptor); Proto-Oncogene Proteins c-akt; Real-Time Polymerase Chain Reaction; Receptors, Leptin; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta

Chemokine (CC-motif) receptor-like 2 (CCRL2) is a decoy receptor and regulates the local responses of the chemokine chemerin. Recently our group has shown that the functional chemerin receptor, chemokine-like receptor 1 (CMKLR1), correlates with fibrosis and non-alcoholic steatohepatitis (NASH) score in males only. In our current study, we wanted to know whether CCRL2 shows similar correlations as CMKLR1. Therefore, we analyzed the hepatic expression of CCRL2 in murine NASH and in liver tissues obtained from 85 patients with non-alcoholic fatty liver disease (NAFLD) and 33 controls. CCRL2 mRNA was not significantly changed in murine and human NASH liver. CCRL2 mRNA levels were positively correlated with inflammation, fibrosis and NASH scores in the patients. Concordantly, CCRL2 was related to the mRNA levels of F4/80, transforming growth factor beta and alpha smooth muscle actin in murine NASH. In the human cohort, CCRL2 mRNA correlated with fibrosis score and CMKLR1 mRNA in both gender. CCRL2 mRNA was induced in the liver of type 2 diabetes and hypercholesterolemic patients, but still positively correlated with fibrosis score when these patients were excluded from calculations. Human hepatic stellate cells (HSC), hepatic sinusoidal endothelial cells and Kupffer cells (KC) express CCRL2 mRNA. TNF induces CCRL2 expression in HSC and lipopolysaccharide in KC suggesting that correlations identified in NAFLD patients are partly related to the activation of these cells.

Topics: Adult; Aged; Aged, 80 and over; Animals; Body Mass Index; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; Hepatic Stellate Cells; Humans; Hypercholesterolemia; Kupffer Cells; Liver; Male; Mice; Middle Aged; Non-alcoholic Fatty Liver Disease; Receptors, CCR; Receptors, Chemokine; Receptors, G-Protein-Coupled; RNA, Messenger; Transforming Growth Factor beta; Young Adult

Diabetic nephropathy (DN), a common complication associated with both type I and type II diabetes mellitus (DM), is a major cause of chronic nephropathy and a common cause of end-stage renal diseases (ESRD) throughout the world. This study is aimed to determine whether dencichine (De) can ameliorate renal damage in high-glucose-and-fat diet combined STZ (streptozocin) induced DN in type II DM rats and to investigate the potential underlying mechanisms. Markers of metabolism, diabetes, and renal function, and levels of extracellular matrix (ECM) collagen I (Col I), collagen IV (Col IV), fibronectin (FN) and laminin (LN), and of proteins in the TGF-β/Smad pathway were analysed through RT-PCR, western blot, immunofluorescence and immunohistochemistry. The results show that De significantly alleviates metabolism disorder, improved renal function, relieved pathological alterations in the glomerulus of DN rats, decreased ECM deposition and increased the ratio of matrix metalloproteinase (MMP)-9 to tissue inhibitor of metalloproteinase (TIMP)-1 both in vivo and in vitro. Moreover, De negatively regulated TGF-β/Smad signalling pathway and increased the expression of Smad7, an endogenic inhibitory Smad located downstream of the signalling pathway. In conclusion, we provide experimental evidence indicating that the renoprotective effect of De could significantly prevent the progression of DN possibly attribute to down-regulation of the TGF-β/Smad pathway and rebalance the deposition and degradation of ECM proteins.

Topics: Amino Acids, Diamino; Animals; Cell Line; Cell Proliferation; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Extracellular Matrix; Kidney; Male; Rats; Rats, Sprague-Dawley; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

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

Cardiac fibrosis and chronic inflammation are common complications in type 2 diabetes mellitus (T2D). Since nucleotide oligomerization-binding domain 1 (NOD1), an innate immune receptor, is involved in the pathogenesis of insulin resistance and diabetes outcomes, we sought to investigate its involvement in cardiac fibrosis. Here, we show that selective staining of cardiac fibroblasts from T2D (db/db;db) mice exhibits up-regulation and activation of the NOD1 pathway, resulting in enhanced NF-κB and TGF-β signalling. Activation of the TGF-β pathway in cardiac fibroblasts from db mice was prevented after inhibition of NF-κB with BAY-11-7082 (BAY). Moreover, fibrosis progression in db mice was also prevented by BAY treatment. Enhanced TGF-β signalling and cardiac fibrosis of db mice was dependent, at least in part, on the sequential activation of NOD1 and NF-κB since treatment of db mice with a selective NOD1 agonist induced activation of the TGF-β pathway, but co-administration of a NOD1 agonist plus BAY, or a NOD1 inhibitor prevented the NOD1-induced fibrosis. Therefore, NOD1 is involved in cardiac fibrosis associated with diabetes, and establishes a new mechanism for the development of heart fibrosis linked to T2D.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diaminopimelic Acid; Endomyocardial Fibrosis; Gene Expression Regulation; Humans; Insulin; Insulin Resistance; Mice; Mice, Transgenic; Myocardium; NF-kappa B; NIH 3T3 Cells; Nitriles; Nod1 Signaling Adaptor Protein; Signal Transduction; Sulfones; Transforming Growth Factor beta

Recent studies have suggested that renal Nox is important in the progression of diabetic nephropathy. Therefore, we investigated the effect of a novel pan-NOX-inhibitor, APX-115, on diabetic nephropathy in type 2 diabetic mice. Eight- week-old db/m and db/db mice were treated with APX-115 for 12 weeks. APX-115 was administered by oral gavage at a dose of 60 mg/kg per day. To compare the effects of APX-115 with a dual Nox1/Nox4 inhibitor, db/db mice were treated with GKT137831 according to the same protocol. APX-115 significantly improved insulin resistance in diabetic mice, similar to GKT137831. Oxidative stress as measured by plasma 8-isoprostane level was decreased in the APX-115 group compared with diabetic controls. All lipid profiles, both in plasma and tissues improved with Nox inhibition. APX-115 treatment decreased Nox1, Nox2, and Nox4 protein expression in the kidney. APX-115 decreased urinary albumin excretion and preserved creatinine level. In diabetic kidneys, APX-115 significantly improved mesangial expansion, but GKT137831 did not. In addition, F4/80 infiltration in the adipose tissue and kidney decreased with APX-115 treatment. We also found that TGF-β stimulated ROS generation in primary mouse mesangial cells (pMMCs) from wild-type, Nox1 KO, and Duox1 KO mice, but did not induce Nox activity in pMMCs from Nox2 knockout (KO), Nox4 KO, or Duox2 KO mice. These results indicate that activating Nox2, Nox4, or Duox2 in pMMCs is essential for TGF-β-mediated ROS generation. Our findings suggest that APX-115 may be as effective or may provide better protection than the dual Nox1/Nox4 inhibitor, and pan-Nox inhibition with APX-115 might be a promising therapy for diabetic nephropathy.

Topics: Animals; Blotting, Western; Cells, Cultured; Cytokines; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme Inhibitors; Female; Gene Expression; Isoenzymes; Kidney; Lipid Peroxidation; Lipids; Male; Mesangial Cells; Mice, Inbred C57BL; Mice, Knockout; NADPH Oxidases; Organ Size; Protective Agents; Pyrazoles; Pyrazolones; Pyridines; Pyridones; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transforming Growth Factor beta

Type 2 diabetes mellitus (DM) is a risk factor for the development of active tuberculosis (TB), although its role in the TB-induced responses in latent TB (LTB) is not well understood. Since Th1, Th2, and Th17 responses are important in immunity to LTB, we postulated that coincident DM could alter the function of these CD4(+) T-cell subsets. To this end, we examined mycobacteria-induced immune responses in the whole blood of individuals with LTB-DM and compared them with responses of individuals without DM (LTB-NDM). T-cell responses from LTB-DM are characterized by diminished frequencies of mono- and dual-functional CD4(+) Th1, Th2, and Th17 cells at baseline and following stimulation with mycobacterial antigens-purified protein derivative, early secreted antigen-6, and culture filtrate protein-10. This modulation was at least partially dependent on IL-10 and TGF-β, since neutralization of either cytokine resulted in significantly increased frequencies of Th1 and Th2 cells but not Th17 cells in LTB-DM but not LTB individuals. LTB-DM is therefore characterized by diminished frequencies of Th1, Th2, and Th17 cells, indicating that DM alters the immune response in latent TB leading to a suboptimal induction of protective CD4(+) T-cell responses, thereby providing a potential mechanism for increased susceptibility to active disease.

Topics: Adult; Aged; Antibodies, Neutralizing; Antigens, Bacterial; Bacterial Proteins; Diabetes Mellitus, Type 2; Disease Susceptibility; Female; Humans; Interleukin-10; Latent Tuberculosis; Lymphocyte Activation; Male; Middle Aged; Th1 Cells; Th17 Cells; Th2 Cells; Transforming Growth Factor beta; Young Adult

Essentials Endothelial protein C receptor (EPCR) promotes diabetic nephropathy (DN) outcome improvement. Renal expression and shedding of EPCR were measured in diabetic patients with or without DN. Inhibition of metalloproteinase-driven EPCR shedding restored glomerular endothelium phenotype. EPCR shedding through metalloproteinase ADAM17 contributes to the worsening of DN.. Background Diabetic nephropathy (DN) represents the leading cause of end-stage renal disease. The endothelial protein C receptor (EPCR) and its ligand (activated protein C) have been shown to ameliorate the phenotype of DN in mice. EPCR activity can be regulated by proteolytic cleavage involving ADAMs, yielding a soluble form of EPCR (sEPCR). Objective To characterize the renal expression and shedding of EPCR during DN. Methods EPCR levels were measured in plasma, urine and biopsy samples of diabetic patients with (n = 73) or without (n = 63) DN. ADAM-induced cleavage of EPCR was investigated in vitro with a human glomerular endothelium cell line. Results DN patients showed higher plasma and urinary levels of sEPCR than diabetic controls (112.2 versus 135.2 ng mL(-1) and 94.35 versus 140.6 ng mL(-1) , respectively). Accordingly, glomerular endothelial EPCR expression was markedly reduced in patients with DN, and this was associated with increased glomerular expression of ADAM-17 and ADAM-10. In vitro, EPCR shedding was induced by incubation of glomerular endothelium in high-glucose medium, and this shedding was suppressed by ADAM-17 inhibition or silencing, which led to improved vascular endothelial cadherin (VE-cadherin) expression and reduced mRNA expression of transforming growth factor (TGF)-β. In addition, EPCR silencing led to minor effects on VE-cadherin but to a significant increase in TGF-β mRNA expression. Conclusion Inhibition of ADAM-driven glomerular EPCR shedding restored the endothelial phenotype of glomerular endothelium, whereas EPCR silencing led to enhanced expression of TGF-β, a marker of endothelial-mesenchymal transition. These findings demonstrate that EPCR shedding driven by ADAMs contributes to the worsening of DN.

Topics: ADAM10 Protein; ADAM17 Protein; Aged; Amyloid Precursor Protein Secretases; Biopsy; Cell Line; Diabetes Mellitus; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelial Protein C Receptor; Endothelium; Female; Gene Silencing; Humans; Kidney; Kidney Glomerulus; Ligands; Male; Membrane Proteins; Metalloproteases; Middle Aged; Phenotype; RNA, Small Interfering; Transforming Growth Factor beta

Hyperglycemia, hyperlipidemia, and insulin resistance are hallmarks of obesity-induced type 2 diabetes, which is often caused by a high-fat diet (HFD). However, the molecular mechanisms underlying HFD-induced insulin resistance have not been elucidated in detail. In this study, we established a Drosophila model to investigate the molecular mechanisms of HFD-induced diabetes. HFD model flies recapitulate mammalian diabetic phenotypes including elevated triglyceride and circulating glucose levels, as well as insulin resistance. Expression of glass bottom boat (gbb), a Drosophila homolog of mammalian transforming growth factor-β (TGF-β), is elevated under HFD conditions. Furthermore, overexpression of gbb in the fat body produced obese and insulin-resistant phenotypes similar to those of HFD-fed flies, whereas inhibition of Gbb signaling significantly ameliorated HFD-induced metabolic phenotypes. We also discovered that tribbles, a negative regulator of AKT, is a target gene of Gbb signaling in the fat body. Overexpression of tribbles in flies in the fat body phenocopied the metabolic defects associated with HFD conditions or Gbb overexpression, whereas tribbles knockdown rescued these metabolic phenotypes. These results indicate that HFD-induced TGF-β/Gbb signaling provokes insulin resistance by increasing tribbles expression.

Topics: Animals; Cell Cycle Proteins; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Drosophila Proteins; Fat Body; Gene Expression Regulation; Humans; Insulin Resistance; Male; Obesity; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Transforming Growth Factor beta

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

The role of inflammation in both diabetes and diabetic kidney disease (DKD) is becoming more widely accepted. However, the role of recently characterized T cell cytokines interleukin (IL)-9 and IL-17 in diabetes and especially DKD is less well studied. Transforming growth factor beta (TGF-β) controls the secretion of both of these cytokines. In this study, we estimated the levels of IL-9, IL-17, and TGF-β in the serum of subjects with normal glucose tolerance (NGT = 88) and subjects with type 2 diabetes without (diabetes mellitus (DM) = 65) and with DKD (DKD = 97) using enzyme-linked immunosorbent assay (ELISA), and we correlated these levels with the clinical risk factors of diabetes and DKD. IL-17 levels showed a serial decline and TGF-β levels showed a serial increase from NGT to DM to DKD (p < 0.001). However, the IL-9 levels were significantly reduced in the DM group compared to the NGT and DKD group (p < 0.001). While TGF-β and IL-17 showed a positive and negative correlation, respectively, with fasting and postprandial glucose levels and glycated hemoglobin (HbA1c), IL-9 showed positive correlation with urea and microalbuminuria. Apart from pro-inflammatory cytokines, T helper (Th) cytokines might play an important role in insulin resistance and DKD.

Topics: Adult; Aged; Albuminuria; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme-Linked Immunosorbent Assay; Fasting; Female; Glycated Hemoglobin; Humans; Insulin Resistance; Interleukin-17; Interleukin-9; Male; Middle Aged; Postprandial Period; Risk Factors; Transforming Growth Factor beta

Type 2 diabetes mellitus (T2DM) is one of the most frequent metabolic disorders in industrialized countries. Among other complications, T2DM patients have an increased fracture risk and delayed fracture healing. We have demonstrated that supraphysiological glucose and insulin levels inhibit primary human osteoblasts׳ maturation. We aimed at developing a more physiologically relevant in vitro model to analyze T2DM-mediated osteoblast changes. Therefore, SCP-1-immortalized pre-osteoblasts were differentiated with T2DM or control (non-obese and obese) sera. Between both control groups, no significant changes were observed. Proliferation was significantly increased (1.69-fold), while AP activity and matrix mineralization was significantly reduced in the T2DM group. Expression levels of osteogenic marker genes and transcription factors were altered, e.g. down-regulation of RUNX2 and SP-7 or up-regulation of STAT1, in the T2DM group. Active TGF-β levels were significantly increased (1.46-fold) in T2DM patients׳ sera. SCP-1 cells treated with these sera showed significantly increased TGF-β signaling (2.47-fold). Signaling inhibition effectively restored osteoblast maturation in the T2DM group. Summarizing our data, SCP-1 cells differentiated in the presence of T2DM patients׳ serum exhibit reduced osteoblast function. Thus, this model has a high physiological impact, as it can identify circulating factors in T2DM patients׳ blood that may affect bone function, e.g. TGF-β.

Topics: Adult; Aged; Alkaline Phosphatase; Bone Diseases, Metabolic; Case-Control Studies; Cell Differentiation; Cell Line; Diabetes Mellitus, Type 2; Female; Gene Expression; Humans; Male; Middle Aged; Osteoblasts; Transforming Growth Factor beta

Tuberculosis (TB) remains an eminent global burden with one third of the world's population latently infected with Mycobacterium tuberculosis (M. tb). Individuals with compromised immune systems are especially vulnerable to M. tb infection. In fact, individuals with Type 2 Diabetes Mellitus (T2DM) are two to three times more susceptible to TB than those without T2DM. In this study, we report that individuals with T2DM have lower levels of glutathione (GSH) due to compromised levels of GSH synthesis and metabolism enzymes. Transforming growth factor beta (TGF-β), a cytokine that is known to decrease the expression of the catalytic subunit of glutamine-cysteine ligase (GCLC) was found in increased levels in the plasma samples from individuals with T2DM, explaining the possible underlying mechanism that is responsible for decreased levels of GSH in individuals with T2DM. Moreover, increased levels of pro-inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-17 (IL-17) were observed in plasma samples isolated from individuals with T2DM. Increased levels of IL-6 and IL-17 was accompanied by enhanced production of free radicals further indicating an alternative mechanism for the decreased levels of GSH in individuals with T2DM. Augmenting the levels of GSH in macrophages isolated from individuals with T2DM resulted in improved control of M. tb infection. Furthermore, cytokines that are responsible for controlling M. tb infection at the cellular and granuloma level such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-2 (IL-2), interferon-gamma (IFN-γ), and interleukin-12 (IL-12), were found to be compromised in plasma samples isolated from individuals with T2DM. On the other hand, interleukin-10 (IL-10), an immunosuppressive cytokine was increased in plasma samples isolated from individuals with T2DM. Overall, these findings suggest that lower levels of GSH in individuals with T2DM lead to their increased susceptibility to M. tb infection.

Topics: Adult; Blotting, Western; Cytokines; Diabetes Complications; Diabetes Mellitus, Type 2; Disease Susceptibility; Flow Cytometry; Glutathione; Humans; Immunoblotting; Interleukin-17; Interleukin-6; Macrophages; Middle Aged; Reactive Oxygen Species; Rosaniline Dyes; Transforming Growth Factor beta; Tuberculosis

To investigate the effects of bariatric surgery on metabolic parameters, incretin hormone secretion, and duodenal and ileal mucosal gene expression.. Nine patients with type 2 diabetes mellitus (T2DM), chronic serum hyperglycemia for more than 2 years, and a body mass index (BMI) of 30-35 kg/m(2) underwent metabolic surgery sleeve gastrectomy with transit bipartition between May 2011 and December 2011. Blood samples were collected pre and 3, 6 and 12 mo postsurgery. Duodenal and ileal mucosa samples were collected pre- and 3 mo postsurgery. Pre- and postoperative blood samples were collected in the fasting state before ingestion of a standard meal (520 kcal) and again 30, 60, 90, and 120 min after the meal to determine hemoglobin A1c (HbA1c) levels and the lipid profile, which consisted of triglyceride and total cholesterol levels. Intestinal gene expression of p53 and transforming growth factor (TGF)-β was analyzed using quantitative reverse-transcription PCR. Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were quantified using the enzyme-linked immunoassay method and analyzed pre- and postoperatively. Student's t test or repeated measurements analysis of variance with Bonferroni corrections were performed as appropriate.. BMI values decreased by 15.7% within the initial 3 mo after surgery (31.29 ± 0.73 vs 26.398 ± 0.68, P < 0.05) and then stabilized at 22% at 6 mo postoperative, resulting in similar values 12 mo postoperatively (20-25 kg/m(2)). All of the patients experienced improved T2DM, with 7 patients (78%) achieving complete remission (HbA1c < 6.5%), and 2 patients (22%) achieving improved diabetes (HbA1c < 7.0% with or without the use of oral hypoglycemic agents). At 3 mo postoperatively, fasting plasma glucose had also decreased (59%) (269.55 ± 18.24 mg/dL vs 100.77 ± 3.13 mg/dL, P < 0.05) with no further significant changes at 6 or 12 mo postoperatively. In the first month postoperatively, there was a complete withdrawal of hypoglycemic medications in all patients, who were taking at least 2 hypoglycemic drugs preoperatively. GLP-1 levels significantly increased after surgery (149.96 ± 31.25 vs 220.23 ± 27.55) (P < 0.05), while GIP levels decreased but not significantly. p53 gene expression significantly increased in the duodenal mucosa (P < 0.05, 2.06 fold) whereas the tumor growth factor-β gene expression significantly increased (P < 0.05, 2.52 fold) in the ileal mucosa after surgery.. Metabolic surgery ameliorated diabetes in all of the patients, accompanied by increased anti-proliferative intestinal gene expression in non-excluded segments of the intestine.

Topics: Adult; Bariatric Surgery; Biomarkers; Biopsy; Blood Glucose; Body Mass Index; Cell Proliferation; Diabetes Mellitus, Type 2; Duodenum; Fasting; Female; Gastrectomy; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Ileum; Intestinal Mucosa; Male; Middle Aged; Obesity; Postprandial Period; Remission Induction; Time Factors; Transforming Growth Factor beta; Treatment Outcome; Tumor Suppressor Protein p53; Weight Loss

This study evaluated the influence of type 2 diabetes mellitus (T2DM) on the gene expression of bone-related factors in alveolar bone tissue from sites designated to receive dental implants. Bone biopsies were harvested from sites of planned implants for 19 systemically healthy patients and 35 patients with T2DM (17 with better-controlled T2DM (glycated haemoglobin (HbA1c) levels ≤8%) and 18 with poorly controlled T2DM (HbA1c levels >8%)). The mRNA levels of tumour necrosis factor alpha, transforming growth factor beta, receptor activator of the nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), runt-related transcription factor 2, alkaline phosphatase, bone sialoprotein (BSP), type I collagen (COL-I), and osteocalcin were evaluated by quantitative real-time polymerase chain reaction. T2DM up-regulates RANKL levels and the ratio of RANKL/OPG, whereas it down-regulates COL-I and BSP expression (P<0.05). Higher mRNA levels of RANKL/OPG were observed in the poorly controlled T2DM patients compared to those with better-controlled T2DM and systemically healthy patients (P<0.05). A lower amount of COL-I and BSP was detected in the biopsies from individuals with poorly controlled T2DM compared to systemically healthy patients (P<0.05). In conclusion, RANKL, RANKL/OPG, COL-I, and BSP are negatively affected in diabetics. Additionally, the patient's glycaemic status appears to modulate bone-related genes in a different manner.

Topics: Adult; Aged; Alkaline Phosphatase; Alveolar Process; Biomarkers; Biopsy; Collagen Type I; Core Binding Factor Alpha 1 Subunit; Dental Implants; Diabetes Mellitus, Type 2; Female; Gene Expression; Humans; Integrin-Binding Sialoprotein; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Real-Time Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

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

Multiple studies have shown that diabetes mellitus is an established risk factor for periodontitis. Recently mesenchymal stem cells derived from periodontal ligament (PDLSCs) have been utilized to reconstruct tissues destroyed by chronic inflammation. However, impact of periodontitis with diabetes mellitus on PDLSCs and mechanisms mediating effects of complex microenvironments remain poorly understood. In this study, we found multiple differentiation potential of PDLSCs from chronic periodontitis with diabetes mellitus donors (D-PDLSCs) was damaged significantly. Inhibition of NF-κB signaling could rescue osteogenic potential of PDLSCs from simple chronic periodontitis patients (P-PDLSCs), whereas did not promote D-PDLSCs osteogenesis. In addition, we found expression of DKK1 in D-PDLSCs did not respond to osteogenic signal and decreased osteogenic potential of D-PDLSCs treated with DKK1 could be reversed. To further elucidate different character between P-PDLSCs and D-PDLSCs, we treated PDLSCs with TNF-α and advanced glycation end products (AGEs), and find out AGEs which enhance effect of TNF-α in PDLSCs might mediate special personality of D-PDLSCs. The adverse effect of AGEs in PDLSCs could be reversed when PDLSCs were treated with DKK1. These results suggested DKK1 mediating WNT signaling might be a therapy target to rescue potential of PDLSCs in periodontitis with diabetes mellitus.

Topics: Adult; Aged; Animals; beta Catenin; Cell Differentiation; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Diabetes Mellitus, Type 2; Glycation End Products, Advanced; Humans; Intercellular Signaling Peptides and Proteins; Male; Mesenchymal Stem Cells; Mice; Mice, Inbred NOD; Mice, SCID; Middle Aged; NF-kappa B; Osteogenesis; Periodontal Ligament; Periodontitis; Transforming Growth Factor beta

Scavenger receptor, class B type I (SR-BI) is a physiologically relevant regulator of high density lipoprotein (HDL) metabolism. Low HDL is a common feature of patients with non-alcoholic fatty liver disease (NAFLD). Here, hepatic SR-BI expression was analyzed in human and murine NAFLD. In primary human hepatocytes NAFLD relevant factors like inflammatory cytokines, lipopolysaccharide and TGF-β did not affect SR-BI protein. Similarly, oleate and palmitate had no effect. The adipokines chemerin, adiponectin, leptin and omentin did not regulate SR-BI expression. Accordingly, hepatic SR-BI was not changed in human and murine fatty liver and non-alcoholic steatohepatits. SR-BI was higher in type 2 diabetes patients but not in those with hypercholesterolemia. The current study indicates a minor if any role of SR-BI in human and murine NAFLD.

Topics: Adiponectin; Adult; Aged; Aged, 80 and over; Animals; Chemokines; Cytokines; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; GPI-Linked Proteins; Hepatocytes; Humans; Intercellular Signaling Peptides and Proteins; Lectins; Leptin; Lipopolysaccharides; Lipoproteins, HDL; Liver; Male; Mice; Middle Aged; Non-alcoholic Fatty Liver Disease; Oleic Acid; Palmitic Acid; Primary Cell Culture; Scavenger Receptors, Class B; Signal Transduction; Transforming Growth Factor beta

βig-h3/TGF-βi is a secreted protein capable of binding to both extracellular matrix and cells. Human genetic studies recently revealed that in the tgfbi gene encoding for βig-h3, three single nucleotide polymorphisms were significantly associated with type 1 diabetes (T1D) risk. Pancreatic islets express βig-h3 in physiological conditions, but this expression is reduced in β-cell insult in T1D. Since the integrity of islets is destroyed by autoimmune T lymphocytes, we thought to investigate the impact of βig-h3 on T-cell activation. We show here that βig-h3 inhibits T-cell activation markers as well as cytotoxic molecule production as granzyme B and IFN-γ. Furthermore, βig-h3 inhibits early T-cell receptor signaling by repressing the activation of the early kinase protein Lck. Moreover, βig-h3-treated T cells are unable to induce T1D upon transfer in Rag2 knockout mice. Our study demonstrates for the first time that T-cell activation is modulated by βig-h3, an islet extracellular protein, in order to efficiently avoid autoimmune response.

Topics: Animals; Autoimmunity; Biomarkers; Cadaver; Cells, Cultured; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Female; Humans; Hypoglycemic Agents; Lymph Nodes; Lymphocyte Activation; Lymphocyte Specific Protein Tyrosine Kinase p56(lck); Mice, Inbred C57BL; Mice, Inbred NOD; Mice, Knockout; Protein Kinase Inhibitors; Receptors, Antigen, T-Cell; Recombinant Proteins; Signal Transduction; Specific Pathogen-Free Organisms; T-Lymphocytes; Transforming Growth Factor beta

Increase in matrix protein content in the kidney is a cardinal feature of diabetic kidney disease. While renal matrix protein content is increased by chronic hyperglycemia, whether it is regulated by acute elevation of glucose and insulin has not been addressed. In this study, we aimed to evaluate whether short duration of combined hyperglycemia and hyperinsulinemia, mimicking the metabolic environment of prediabetes and early type 2 diabetes, induces kidney injury. Normal rats were subjected to either saline infusion (control, n = 4) or 7 h of combined hyperglycemic-hyperinsulinemic clamp (HG+HI clamp; n = 6). During the clamp, plasma glucose and plasma insulin were maintained at about 350 mg/dl and 16 ng/ml, respectively. HG+HI clamp increased the expression of renal cortical transforming growth factor-β (TGF-β) and renal matrix proteins, laminin and fibronectin. This was associated with the activation of SMAD3, Akt, mammalian target of rapamycin (mTOR) complexes, and ERK signaling pathways and their downstream target events in the initiation and elongation phases of mRNA translation, an important step in protein synthesis. Additionally, HG+HI clamp provoked renal inflammation as shown by the activation of Toll-like receptor 4 (TLR4) and infiltration of CD68-positive monocytes. Urinary F2t isoprostane excretion, an index of renal oxidant stress, was increased in the HG+HI clamp rats. We conclude that even a short duration of hyperglycemia and hyperinsulinemia contributes to activation of pathways that regulate matrix protein synthesis, inflammation, and oxidative stress in the kidney. This finding could have implications for the control of short-term rises in blood glucose in diabetic individuals at risk of developing kidney disease.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme Activation; Fibronectins; Fibrosis; Hyperglycemia; Hyperinsulinism; Inflammation; Kidney; Laminin; Male; MAP Kinase Signaling System; NF-kappa B; Oxidative Stress; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; RNA, Messenger; Smad3 Protein; Toll-Like Receptor 4; TOR Serine-Threonine Kinases; Transforming Growth Factor beta

Inflammation and its consequent fibrosis are two main features of diabetic nephropathy (DN), but target therapy on these processes for DN remains yet ineffective. We report here that miR-29b is a novel therapeutic agent capable of inhibiting progressive renal inflammation and fibrosis in type 2 diabetes in db/db mice. Under diabetic conditions, miR-29b was largely downregulated in response to advanced glycation end (AGE) product, which was associated with upregulation of collagen matrix in mesangial cells via the transforming growth factor-β (TGF-β)/Smad3-dependent mechanism. These pathological changes were reversed by overexpressing miR-29b, but enhanced by knocking-down miR-29b. Similarly, loss of renal miR-29b was associated with progressive diabetic kidney injury, including microalbuminuria, renal fibrosis, and inflammation. Restored renal miR-29b by the ultrasound-based gene therapy was capable of attenuating diabetic kidney disease. Further studies revealed that inhibition of Sp1 expression, TGF-β/Smad3-dependent renal fibrosis, NF-κB-driven renal inflammation, and T-bet/Th1-mediated immune response may be mechanisms associated with miR-29b treatment in db/db mice. In conclusion, miR-29b may play a protective role in diabetic kidney disease and may have therapeutic potential for diabetic kidney complication.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibrosis; Genetic Therapy; Humans; Inflammation; Mice; MicroRNAs; Signal Transduction; Smad3 Protein; Transforming Growth Factor beta

Microfibril-associated glycoprotein 1 (MAGP1) is a component of extracellular matrix microfibrils. Here we show that MAGP1 expression is significantly altered in obese humans, and inactivation of the MAGP1 gene (Mfap2(-/-)) in mice results in adipocyte hypertrophy and predisposition to metabolic dysfunction. Impaired thermoregulation was evident in Mfap2(-/-) mice prior to changes in adiposity, suggesting a causative role for MAGP1 in the increased adiposity and predisposition to diabetes. By 5 weeks of age, Mfap2(-/-) mice were maladaptive to cold challenge, uncoupling protein-1 expression was attenuated in the brown adipose tissue, and there was reduced browning of the subcutaneous white adipose tissue. Levels of transforming growth factor-β (TGF-β) activity were elevated in Mfap2(-/-) adipose tissue, and the treatment of Mfap2(-/-) mice with a TGF-β-neutralizing antibody improved their body temperature and prevented the increased adiposity phenotype. Together, these findings indicate that the regulation of TGF-β by MAGP1 is protective against the effects of metabolic stress, and its absence predisposes individuals to metabolic dysfunction.

Topics: Adipocytes; Adipose Tissue; Animals; Contractile Proteins; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Genetic Pleiotropy; Genetic Predisposition to Disease; Male; Mice; Mice, Inbred C57BL; Obesity; Phenotype; RNA Splicing Factors; Signal Transduction; Thermogenesis; Transforming Growth Factor beta

Transforming growth factor beta-induced (TGFBI/βIG-H3), also known as βig-H3, is a protein inducible by TGFβ1 and secreted by many cell types. It binds to collagen, forms part of the extracellular matrix and interacts with integrins on the cell surface. Recombinant TGFBI and transgenic TGFBI overexpression can promote both islet survival and function. In this study, we generated TGFBI KO mice and further assessed TGFBI function and signaling pathways in islets. Islets from KO mice were of normal size and quantity, and these animals were normoglycemic. However, KO islet survival and function was compromised in vitro. In vivo, KO donor islets became inferior to wild-type donor islets in achieving normoglycemia when transplanted into KO diabetic recipients. TGFBI KO mice were more prone to straptozotocin-induced diabetes than the wild-type counterpart. Phosphoprotein array analysis established that AKT1S1, a molecule linking the AKT and mTORC1 signaling pathways, was modulated by TGFBI in islets. Phosphorylation of four molecules in the AKT and mTORC1 signaling pathway, i.e. AKT, AKT1S1, RPS6 and EIF4EBP1, was upregulated in islets upon TGFBI stimulation. Suppression of AKT activity by a chemical inhibitor, or knockdown of AKT1S1, RPS6 and EIF4EBP1 expression by small interfering RNA, modulated islet survival, proving the relevance of these molecules in TGFBI-triggered signaling. Human genetic studies revealed that in the TGFBI gene and its vicinity, three single-nucleotide polymorphisms were significantly associated with type 1 diabetes risks, and one with type 2 diabetes risks. Our study suggests that TGFBI is a potential risk gene for human diabetes.

Topics: Animals; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Genetic Predisposition to Disease; Humans; Islets of Langerhans; Islets of Langerhans Transplantation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Phosphoproteins; Phosphorylation; Polymorphism, Single Nucleotide; Risk Factors; Signal Transduction; Tissue Survival; Transforming Growth Factor beta; Transforming Growth Factor beta1

Topics: Adipocytes; Adipose Tissue; Animals; Contractile Proteins; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Male; Obesity; RNA Splicing Factors; Transforming Growth Factor beta

Type 2 diabetes (T2DM) promotes premature atherosclerosis and inferior prognosis after arterial reconstruction. Vascular smooth muscle cells (SMC) respond to patho/physiological stimuli, switching between quiescent contractile and activated synthetic phenotypes under the control of microRNAs (miRs) that regulate multiple genes critical to SMC plasticity. The importance of miRs to SMC function specifically in T2DM is unknown. This study was performed to evaluate phenotype and function in SMC cultured from non-diabetic and T2DM patients, to explore any aberrancies and investigate underlying mechanisms. Saphenous vein SMC cultured from T2DM patients (T2DM-SMC) exhibited increased spread cell area, disorganised cytoskeleton and impaired proliferation relative to cells from non-diabetic patients (ND-SMC), accompanied by a persistent, selective up-regulation of miR-143 and miR-145. Transfection of premiR-143/145 into ND-SMC induced morphological and functional characteristics similar to native T2DM-SMC; modulating miR-143/145 targets Kruppel-like factor 4, alpha smooth muscle actin and myosin VI. Conversely, transfection of antimiR-143/145 into T2DM-SMC conferred characteristics of the ND phenotype. Exposure of ND-SMC to transforming growth factor beta (TGFβ) induced a diabetes-like phenotype; elevated miR-143/145, increased cell area and reduced proliferation. Furthermore, these effects were dependent on miR-143/145. In conclusion, aberrant expression of miR-143/145 induces a distinct saphenous vein SMC phenotype that may contribute to vascular complications in patients with T2DM, and is potentially amenable to therapeutic manipulation.

Topics: Actins; Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; Glucose; Humans; Hypoglycemic Agents; Interleukin-1alpha; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Male; MicroRNAs; Middle Aged; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Myosin Heavy Chains; Phenotype; Primary Cell Culture; Saphenous Vein; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Type 1 diabetes is recognized as an autoimmune inflammatory disease and low grade inflammation is also observed in type 2 diabetic patients. Interleukin 17 (IL-17) is a new player in inflammation. Th17 cells, as the main source of IL-17, require transforming growth factor β (TGF-β) and interleukin 23 (IL-23). The aim of this study was to investigate serum IL-17, IL-23 and TGF-β levels in diabetic patients and controls. In this case-control study, serum levels of IL-17, IL-23, and TGF-β were measured in 24 type 1 diabetic patients and 30 healthy controls using the ELISA method. Simultaneously, the same methodology was used to compare serum concentration of these three cytokines in 38 type 2 diabetic patients and 40 healthy controls. There was no significant difference between serum levels of IL-17 and IL-23 cytokines between cases and controls. However, TGF-β was significantly lower in type 1 diabetic patients (P < 0.001). Serum IL-17 and IL-23 levels demonstrate no association with type 1 and type 2 diabetes, but, in line with previous studies, TGF-β levels were lower in type 1 diabetic patients.

Topics: Adolescent; Adult; Case-Control Studies; Child; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Healthy Volunteers; Humans; Interleukin-17; Interleukin-23; Male; Transforming Growth Factor beta

Dysfunction or death of pancreatic β cells underlies both types of diabetes. This functional decline begins with β cell stress and de-differentiation. Current drugs for type 2 diabetes (T2D) lower blood glucose levels but they do not directly alleviate β cell stress nor prevent, let alone reverse, β cell de-differentiation. We show here that Urocortin 3 (Ucn3), a marker for mature β cells, is down-regulated in the early stages of T2D in mice and when β cells are stressed in vitro. Using an insulin expression-coupled lineage tracer, with Ucn3 as a reporter for the mature β cell state, we screen for factors that reverse β cell de-differentiation. We find that a small molecule inhibitor of TGFβ receptor I (Alk5) protects cells from the loss of key β cell transcription factors and restores a mature β cell identity even after exposure to prolonged and severe diabetes.

Topics: Animals; Biomarkers; Cell Dedifferentiation; Cytokines; Diabetes Mellitus, Type 2; Humans; Insulin Resistance; Insulin-Secreting Cells; Mice, Inbred C57BL; Nerve Tissue Proteins; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; Signal Transduction; Small Molecule Libraries; Stress, Physiological; Transcription Factors; Transforming Growth Factor beta; Up-Regulation; Urocortins

Diabetic nephropathy (DN) is a serious complication for patients with diabetes mellitus (DM). Emerging evidence suggests that complement C3a is involved in the progression of DN. The aim of this study was to investigate the effect of C3a Receptor Agonist (C3aRA) on DN and its potential mechanism of action in rats with type 2 diabetes mellitus (T2DM).. T2DM was induced in SD rats by a high fat diet (HFD) plus repeated low dose streptozocin (STZ) injections. T2DM rats were treated with vehicle or C3aRA for 8 weeks. Biochemical analysis, HE and PAS stains were performed to evaluate the renal function and pathological changes. Human renal glomerular endothelial cells (HRGECs) were cultured and treated with normal glucose (NG), high glucose (HG), HG+C3a, HG+C3a+C3aRA and HG+C3a+BAY-11-7082 (p-IKBα Inhibitor) or SIS3 (Smad3 Inhibitor), respectively. Real-time PCR, immunofluorescent staining and western blot were performed to detect the mRNA and protein levels, respectively.. T2DM rats showed worse renal morphology and impaired renal function compared with control rats, including elevated levels of serum creatinine (CREA), blood urea nitrogen (BUN) and urine albumin excretion (UACR), as well as increased levels of C3a, C3aR, IL-6, p-IKBα, collagen I, TGF-β and p-Smad3 in the kidney of T2DM rats and C3a-treated HRGECs. In contrast, C3aRA treatment improved renal function and morphology, reduced CREA, UACR and the intensity of PAS and collagen I staining in the kidney of T2DM rats, and decreased C3a, p-IKBα, IL-6, TGF-β, p-Smad3 and collagen I expressions in HRGECs and T2DM rats.. C3a mediated pro-inflammatory and pro-fibrotic responses and aggravated renal injury in T2DM rats. C3aRA ameliorated T2DN by inhibiting IKBα phosphorylation and cytokine release, and also TGF-β/Smad3 signaling and ECM deposition. Therefore, complement C3a receptor is a potential therapeutic target for DN.

Topics: Animals; Blotting, Western; Complement C3a; Diabetes Mellitus, Type 2; Diabetic Nephropathies; I-kappa B Kinase; Male; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptors, Complement; Smad3 Protein; Transforming Growth Factor beta

Emerging evidence suggests that activin with its associated receptors, second messengers, and antagonists would be excellent targets for therapeutic drug development in the treatment of diabetes. We undertook the current study to investigate the ability to extrapolate findings from rodent studies to human islets in which data thus far has been scarce. We tested the hypothesis that human islets synthesize activin and that activin participates in the regulation of islet β-cells. Human islets from 33 separate isolations were categorized based on functional status, culture status and diabetic status. Statistical comparisons were made by ANOVA with Tukey post-hoc adjustment for multiple comparisons. Experiments investigating activin utilized qPCR, FACS cell sorting, immunofluorescent antibody staining, functionality assays, viability assays and protein secretion assays. We have defined the transcript expression patterns of activin and the TGFβ superfamily in human islets. We found INHBA (the gene encoding activin A) to be the most highly expressed of the superfamily in normal, cultured islets. We elucidated a link between the islet microenvironment and activin A. We found differential ligand expression based on diabetic, culture and functional status. Further, this is also the first report that links direct effects of activin A with the ability to restore glucose-stimulated insulin secretion in human islets from type 2 diabetic donors thereby establishing the relevance of targeting activin for therapeutic drug development.

Topics: Activins; Adult; Aged; Cell Survival; Cells, Cultured; Diabetes Mellitus, Type 2; Female; Flow Cytometry; Gene Expression; Glucagon-Secreting Cells; Humans; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Real-Time Polymerase Chain Reaction; Transforming Growth Factor beta; Young Adult

Cardiovascular complications are a leading cause of death in patients with type 2 diabetes mellitus (T2DM). Diastolic dysfunction is one of the earliest manifestations of diabetes-induced changes in left ventricular (LV) function, and results from a reduced rate of relaxation and increased stiffness. The mechanisms responsible for increased stiffness are not completely understood. Chronic hyperglycemia, advanced glycation endproducts (AGEs), and increased levels of proinflammatory and profibrotic cytokines are molecular pathways known to be involved in regulating extracellular matrix (ECM) synthesis and accumulation resulting in increased LV diastolic stiffness. Experiments were conducted using a genetically-induced mouse model of T2DM generated by a point mutation in the leptin receptor resulting in nonfunctional leptin receptors (db/db murine model). This study correlated changes in LV ECM and stiffness with alterations in basal activation of signaling cascades and expression of profibrotic markers within primary cultures of cardiac fibroblasts from diabetic (db/db) mice with nondiabetic (db/wt) littermates as controls. Primary cultures of cardiac fibrobroblasts were maintained in 25 mM glucose (hyperglycemic-HG; diabetic db/db) media or 5 mM glucose (normoglycemic-NG, nondiabetic db/wt) media. The cells then underwent a 24-hour exposure to their opposite (NG; diabetic db/db) media or 5 mM glucose (HG, nondiabetic db/wt) media. Protein analysis demonstrated significantly increased expression of type I collagen, TIMP-2, TGF-β, PAI-1 and RAGE in diabetic db/db cells as compared to nondiabetic db/wt, independent of glucose media concentration. This pattern of protein expression was associated with increased LV collagen accumulation, myocardial stiffness and LV diastolic dysfunction. Isolated diabetic db/db fibroblasts were phenotypically distinct from nondiabetic db/wt fibroblasts and exhibited a profibrotic phenotype in normoglycemic conditions.

Topics: Actins; Animals; Blotting, Western; Cardiomyopathies; Cells, Cultured; Collagen Type I; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Extracellular Matrix; Fibroblasts; Glucose; Male; Mice; Mice, Mutant Strains; Muscle, Smooth; Myocardium; Myofibroblasts; Plasminogen Activator Inhibitor 1; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Reverse Transcriptase Polymerase Chain Reaction; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta

Dyslipidemia is common in patients with diabetes mellitus (DM) and is considered a risk factor for the progression of diabetic nephropathy (DN). Hyperlipidemia and hyperglycemia act synergistically to induce renal injury. The present study was designed to investigate the protective effects of tocotrienols as tocotrienol-rich fraction (TRF) extracted from palm (PO) and rice bran oils (RBO) against lipid induced nephropathy in type-2 diabetic rats and its probable molecular mechanism. Male Wistar rats (175-200 g) were divided into four groups. The first group served as diabetic control, while the second and third groups received PO-TRF and RBO-TRF, respectively by gavage over a period of sixteen weeks post-induction of diabetes. The fourth group comprised of age-matched rats that served as normal control. The effects of TRF on serum lipid profile, oxidative stress markers, expression of TGF-β, fibronectin and collagen type IV were analyzed in the kidney of diabetic rats. Treatment with PO-TRF and RBO-TRF significantly improved glycemic status, serum lipid profile and renal function in type-2 diabetic rats. In addition, TRF supplementation down-regulated the expression of TGF-β, fibronectin and collagen type IV in the kidney of diabetic rats. Transforming growth factor-β (TGF-β) plays a critical role in progression of DN, but its modulation by tocotrienols in DN remains unexplored. TRF ameliorated lipid induced nephropathy in type-2 diabetes by its hypoglycemic, hypolipidemic and antioxidant activities as well as by modulation of TGF-β to prevent increased expression of collagen type IV and fibrinogen. We finally propose a mechanism for the expression of molecular markers that are significant in the events leading to diabetic nephropathy and its modulation by tocotrienols/TRF.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Gene Expression Regulation; Lipids; Male; Plant Extracts; Protective Agents; Random Allocation; Rats; Rats, Wistar; Tocotrienols; Transforming Growth Factor beta

Nox (NADPH oxidase)-derived ROS (reactive oxygen species) have been implicated in the development of diabetic nephropathy. Of the Nox isoforms in the kidney, Nox4 is important because of its renal abundance. In the present study, we tested the hypothesis that GKT136901, a Nox1/4 inhibitor, prevents the development of nephropathy in db/db (diabetic) mice. Six groups of male mice (8-week-old) were studied: (i) untreated control db/m, (ii) low-dose GKT136901-treated db/m (30 mg/kg of body weight per day), (iii) high-dose GKT136901-treated db/m (90 mg/kg of body weight per day), (iv) untreated db/db; (v) low dose GKT136901-treated db/db; and (vi) high-dose GKT136901-treated db/db. GKT136901, in chow, was administered for 16 weeks. db/db mice developed diabetes and nephropathy as evidenced by hyperglycaemia, albuminuria and renal injury (mesangial expansion, tubular dystrophy and glomerulosclerosis). GKT136901 treatment had no effect on plasma glucose or BP (blood pressure) in any of the groups. Plasma and urine TBARSs (thiobarbituric acid-reacting substances) levels, markers of systemic and renal oxidative stress, respectively, were increased in diabetic mice. Renal mRNA expression of Nox4, but not of Nox2, increased, Nox1 was barely detectable in db/db. Expression of the antioxidant enzyme SOD-1 (superoxide dismutase 1) decreased in db/db mice. Renal content of fibronectin, pro-collagen, TGFβ (transforming growth factor β) and VCAM-1 (vascular cell adhesion molecule 1) and phosphorylation of ERK1/2 (extracellular-signal-regulated kinase 1/2) were augmented in db/db kidneys, with no change in p38 MAPK (mitogen-activated protein kinase) and JNK (c-Jun N-terminal kinase). Treatment reduced albuminuria, TBARS and renal ERK1/2 phosphorylation and preserved renal structure in diabetic mice. Our findings suggest a renoprotective effect of the Nox1/4 inhibitor, possibly through reduced oxidative damage and decreased ERK1/2 activation. These phenomena occur independently of improved glucose control, suggesting GKT136901-sensitive targets are involved in complications of diabetes rather than in the disease process.

Topics: Albuminuria; Animals; Blood Glucose; Blood Pressure; Blotting, Western; Body Weight; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Kidney; Male; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; NADH, NADPH Oxidoreductases; NADPH Oxidase 1; NADPH Oxidase 4; NADPH Oxidases; Pyrazoles; Pyridones; Reverse Transcriptase Polymerase Chain Reaction; Superoxide Dismutase; Superoxide Dismutase-1; Thiobarbituric Acid Reactive Substances; Transforming Growth Factor beta; Vascular Cell Adhesion Molecule-1

Healing of tooth extraction sockets in poorly controlled diabetic patients is often delayed and accompanied by severe infection. The exact cellular and molecular mechanisms underlying the pathogenesis of this complication are still not fully understood.. The purpose of this study was to investigate molecular changes associated with delayed oral wound healing in diabetes.. Six to eight weeks old male type 2 diabetes and age matched control inbred mice were used and maxillary molar tooth extractions were performed. At 4 and 7 days after tooth extraction, the edentulous mucosa of the mice were harvested, and analyzed for histology and gene expression of key wound healing factors.. In the diabetic model, histological analysis showed that epithelial tissue migration for wound closure was delayed after tooth extraction compared to the control. Quantitative real-time PCR revealed that expression of the TGF-β1, TGF-β2, TGF-β3, TGFβRII and TGFβRIII genes was significantly downregulated in the diabetic model at 4 and 7 days after tooth extraction.. These results suggest that delayed wound healing of oral mucosa in diabetes may be associated with decreased expression levels of these regulatory genes which play important roles in controlling epithelial wound closure.

Topics: Animals; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Disease Models, Animal; Down-Regulation; Epithelial Cells; Gene Expression Regulation; Gingiva; Interleukin-1beta; Lymphocytes; Male; Matrix Metalloproteinase 8; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Molar; Mouth Mucosa; Protein Serine-Threonine Kinases; Proteoglycans; Re-Epithelialization; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Time Factors; Tooth Extraction; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2; Transforming Growth Factor beta3; Wound Healing

We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy.

Topics: Administration, Oral; Albuminuria; Animals; Antioxidants; Bilirubin; Biliverdine; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Gene Expression Regulation; Humans; Kidney; Male; Mice; Mice, Inbred C57BL; NADPH Oxidases; Oxidative Stress; Phycobilins; Phycocyanin; Spirulina; Superoxides; Time Factors; Transforming Growth Factor beta

As microRNA-21 (miR-21) plays a pathological role in fibrosis, we hypothesised that it may be a therapeutic target for diabetic nephropathy.. Abundance of miR-21 was examined in diabetic kidneys from db/db mice. The therapeutic potential of miR-21 in diabetic kidney injury was examined in db/db mice by an ultrasound-microbubble-mediated miR-21 small hairpin RNA transfer. In addition, the role and mechanisms of miR-21 in diabetic renal injury were examined in vitro under diabetic conditions in rat mesangial and tubular epithelial cell lines by overexpressing or downregulating miR-21.. In db/db mice, a mouse model of type 2 diabetes, renal miR-21 at age 20 weeks was increased twofold compared with db/m (+) mice at the same age, and this increase was associated with the development of microalbuminuria and renal fibrosis and inflammation. More importantly, gene transfer of miR-21 knockdown plasmids into the diabetic kidneys of db/db mice at age 10 weeks significantly ameliorated microalbuminuria and renal fibrosis and inflammation at age 20 weeks, revealing a therapeutic potential for diabetic nephropathy by targeting miR-21. Overexpression of miR-21 in kidney cells enhanced, but knockdown of miR-21 suppressed, high-glucose-induced production of fibrotic and inflammatory markers. Targeting Smad7 may be a mechanism by which miR-21 regulates renal injury because knockdown of renal miR-21 restored Smad7 levels and suppressed activation of the TGF-β and NF-κB signalling pathways.. Inhibition of miR-21 might be an effective therapy for diabetic nephropathy.

Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Diabetic Nephropathies; In Situ Hybridization; Kidney; Male; Mice; Mice, Inbred C57BL; MicroRNAs; Rats; Smad7 Protein; Transforming Growth Factor beta

Genome-wide association studies (GWASs) have discovered association of several loci with Type 2 diabetes (T2D), a common complex disease characterized by impaired insulin secretion by pancreatic β cells and insulin signaling in target tissues. However, effect of genetic risk variants on continuous glycemic measures in nondiabetic subjects mainly elucidates perturbation of insulin secretion. Also, the disease associated genes do not clearly converge on functional categories consistent with the known aspects of T2D pathophysiology. We used a systems biology approach to unravel genome to phenome correlation in T2D. We first examined enrichment of pathways in genes identified in T2D GWASs at genome-wide or lower levels of significance. Genes at lower significance threshold showed enrichment of insulin secretion related pathway. Notably, physical and genetic interaction network of these genes showed robust enrichment of insulin signaling and other T2D pathophysiology related pathways including insulin secretion. The network also overrepresented genes reported to interact with insulin secretion and insulin action targeting antidiabetic drugs. The drug interacting genes themselves showed overrepresentation of insulin signaling and other T2D relevant pathways. Next, we generated genome-wide expression profiles of multiple insulin responsive tissues from nondiabetic and diabetic patients. Remarkably, the differentially expressed genes showed significant overlap with the network genes, with the intersection showing enrichment of insulin signaling and other pathways consistent with T2D pathophysiology. Literature search led our genomic, interactomic, transcriptomic and toxicogenomic evidence to converge on TGF-beta signaling, a pathway known to play a crucial role in pancreatic islets development and function, and insulin signaling. Cumulatively, we find that GWAS genes relate directly to insulin secretion and indirectly, through collaborating with other genes, to insulin resistance. This seems to support the epidemiological evidence that environmentally triggered insulin resistance interacts with genetically programmed β cell dysfunction to precipitate diabetes.

Topics: Diabetes Mellitus, Type 2; Female; Gene Expression Profiling; Gene Expression Regulation; Gene-Environment Interaction; Genetic Association Studies; Genome-Wide Association Study; Genome, Human; Genotype; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Phenotype; Signal Transduction; Systems Biology; Transforming Growth Factor beta

We have previously reported that intrarenal angiotensin II (Ang II) levels are increased long before diabetes becomes apparent in obese Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats, a model of type 2 diabetes. In this study, we examined the changes in intrarenal renin-angiotensin system (RAS) activity in the developing kidneys of OLETF rats. Ang II contents and mRNA levels of RAS components were measured in male OLETF and control Long-Evans Tokushima (LETO) rats at postnatal days (PND) 1, 5, and 15, and at 4-30 weeks of age. In both LETO and OLETF rats, kidney Ang II levels peaked at PND 1, then decreased during the pre- and post-weaning periods. However, Ang II levels and gene expression of RAS components, including angiotensinogen (AGT), renin, and angiotensin-converting enzyme (ACE), were not significantly different between LETO and OLETF rats. Intrarenal Ang IIcontents further decreased during puberty (from 7 to 11 weeks of age) in LETO rats, bur not in OLETF rats. At 11 weeks of age, kidney Ang II levels, urinary AGT excretion, and mRNA levels of AGT and renin were higher in OLETF rats than in LETO rats, while blood glucose levels were not significantly different between these groups of rats. These data indicate that continued intrarenal expression of Ang II during pubescence contributes to the increases in intrarenal Ang II levels in prediabetic OLETF rats, and is associated with increased intrarenal AGT and renin expression. Inappropriate activation of the intrarenal RAS in the prediabetic stage may facilitate the onset and development of diabetic nephropathy in later life.

Topics: Albuminuria; Angiotensin II; Angiotensinogen; Animals; Blood Glucose; Blood Pressure; Body Weight; Collagen; Connective Tissue Growth Factor; Creatinine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; Kidney; Organ Size; Peptidyl-Dipeptidase A; Rats; Rats, Inbred OLETF; Receptors, Angiotensin; Renin; Renin-Angiotensin System; Time Factors; Transforming Growth Factor beta

The aim of this study is to evaluate the gene expression of immune-inflammatory markers in gingival biopsies of patients with type 2 diabetes with chronic periodontitis (CP).. Gingival biopsies were harvested from systemically and periodontally healthy patients (SPH), systemically healthy patients with CP (SHCP), and patients with better-controlled and poorly controlled diabetes and CP. The levels of mRNA of interleukin (IL)-17, IL-6, IL-23, IL-10, IL-4, interferon-γ, toll-like receptor (TLR)-2, TLR-4, osteoprotegerin, receptor activator of nuclear factor-kappa B ligand (RANKL), tumor necrosis factor-α, transforming growth factor-β, transcription factor forkhead box p3, transcription factor orphan nuclear receptor C2 (RORC2), and receptor of advanced glycation end products (RAGE) were evaluated by quantitative real-time polymerase chain reaction.. All CP groups presented higher levels of mRNA of TLR-2, TLR-4, IL-17, RANKL, and RAGE and a higher frequency of IL-17 and TLR-2 mRNA-positive biopsies when compared to SPH (P <0.05). There was a higher frequency of detection of RORC2 in the biopsies from both groups with diabetes compared to the other groups (P <0.05). The frequency of IL-4 mRNA-positive tissues was lower in patients with diabetes compared to SHCP (P <0.05).. CP, but not type 2 diabetes mellitus, significantly affected the expressions of the evaluated genes related to the innate and adaptive immune responses.

Topics: Adaptive Immunity; Adult; Biomarkers; Chronic Periodontitis; Cytokines; Diabetes Mellitus, Type 2; Female; Forkhead Transcription Factors; Gingiva; Humans; Immunity, Innate; Inflammation Mediators; Interferon-gamma; Interleukin-10; Interleukin-12; Interleukin-17; Interleukin-4; Interleukin-6; Male; Middle Aged; Nuclear Receptor Subfamily 1, Group F, Member 3; Osteoprotegerin; RANK Ligand; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Toll-Like Receptor 2; Toll-Like Receptor 4; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

The TGF-β/MAD homologue (SMAD) and nuclear factor κB (NF-κB) signalling pathways have been shown to play a critical role in the development of renal fibrosis and inflammation in diabetic nephropathy. We therefore examined whether targeting these pathways by a kidney-targeting Smad7 gene transfer has therapeutic effects on renal lesions in the db/db mouse model of type 2 diabetes.. We delivered Smad7 plasmids into the kidney of db/db mice using kidney-targeting, ultrasound-mediated, microbubble-inducible gene transfer. The histopathology, ultrastructural pathology and pathways of TGF-β/SMAD2/3-mediated fibrosis and NF-κB-dependent inflammation were evaluated.. In this mouse model of type 2 diabetes, Smad7 gene therapy significantly inhibited diabetic kidney injury, compared with mice treated with empty vectors. Symptoms inhibited included: (1) proteinuria and renal function impairment; (2) renal fibrosis such as glomerular sclerosis, tubulo-interstitial collagen matrix abundance and renal inflammation, including Inos (also known as Nos2), Il1b and Mcp1 (also known as Ccl2) upregulation, as well as macrophage infiltration; and (3) podocyte and endothelial cell injury as demonstrated by immunohistochemistry and/or electron microscopy. Further study demonstrated that the improvement of type 2 diabetic kidney injury by overexpression of Smad7 was associated with significantly inhibited local activation of the TGF-β/SMAD and NF-κB signalling pathways in the kidney.. Our results clearly demonstrate that kidney-targeting Smad7 gene transfer may be an effective therapy for type 2 diabetic nephropathy, acting via simultaneous modulation of the TGF-β/SMAD and NF-κB signalling pathways.

Topics: Animals; Apoptosis; Diabetes Complications; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Gene Transfer Techniques; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Microscopy, Confocal; NF-kappa B; Podocytes; Polymerase Chain Reaction; Signal Transduction; Smad Proteins; Smad7 Protein; Transforming Growth Factor beta; Ultrasonics

The protective effects of TGF-β have been documented in various autoimmune diseases, mostly in organ-specific autoimmunity including type 1 diabetes mellitus (T1DM). However, TGF-β also plays a role as a pro-inflammatory mediator by induction of Th17 cytokine production. IL-23 also plays a key role in differentiation of Th17 cells, which are implicated in pathogenesis of autoimmune conditions including T1DM. The aim of this study was to investigate and compare the difference in the level of TGF-β1 and IL-23 gene expression in unstimulated peripheral blood mononuclear cells (PBMCs) of patients with different forms of diabetes compared with normal healthy controls subjects. Patients with T1DM were grouped as early-onset T1DM (N = 20) with age at diagnosis <18 years and late-onset T1DM (N = 20) with the age at onset >18 years. Patients with T2DM (N = 20) and normal healthy controls (N = 20) were recruited from the same area. TGF-β1 and IL-23 gene expression in fresh unstimulated PBMCs was determined in each group using quantitative real-time PCR. The results confirmed that a significant difference in TGF-β1 and IL-23 gene expression was observed in both forms of juvenile-onset T1DM and adult-onset T1DM compared to the controls and T2DM patients. There was no significant difference for TGF-β gene expression in patients with T2DM and controls. We therefore conclude that our results support the previous data on TGF-β gene down-regulation in T1DM. Also up-regulation of IL-23 has been observed in T1DM whilst it was down-regulated in T2DM. We also found no significant difference between juvenile-onset and adult-onset T1DM indicating same mechanism might be involved in the pathogenesis of both types. More studies on different cytokines in Th17 pathways are required to further confirm our finding.

Topics: Adolescent; Adult; Age of Onset; Aged; Child; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; Humans; Interleukin-23; Iran; Leukocytes, Mononuclear; Male; Middle Aged; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Young Adult

We sought to identify novel urinary biomarkers of kidney function in type 2 diabetes. We screened the renal transcriptome of db/db and db/m mice for differentially expressed mRNA transcripts that encode secreted proteins with human orthologs. Whether elevated urine levels of the orthologous proteins correlated with diminished glomerular filtration rate was tested in a cross-sectional study of n = 56 patients with type 2 diabetes. We identified 36 putative biomarker genes in db/db kidneys: 31 upregulated and 5 downregulated. Urinary protein levels of six selected candidates (endothelin-1, lipocalin-2, transforming growth factor-β, growth and differentiation factor-15, interleukin-6, and macrophage chemoattractant protein-1) were elevated in type 2 diabetic patients with subnormal glomerular filtration rate (i.e., <90 ml·min(-1)·1.73 m(-2)), independent of microalbuminuria, age, sex, race, and use of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists. In contrast, urinary levels of fibroblast growth factor were not increased. A composite variable of urine albumin and any of the six candidate markers was associated with subnormal estimated glomerular filtration rate more closely than albumin alone. In addition, urinary endothelin-1, growth and differentiation factor-15, and interleukin-6 were associated with a marker of proximal tubule damage, N-acetyl-β-d-glucosaminidase activity. These results suggest that gene expression profiling in diabetic mouse kidney can complement existing proteomic-based approaches for renal biomarker discovery in humans.

Topics: Acute-Phase Proteins; Adult; Animals; Biomarkers; Case-Control Studies; Chemokine CCL2; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Female; Glomerular Filtration Rate; Growth Differentiation Factor 15; Humans; Immunoassay; Interleukin-6; Kidney; Lipocalin-2; Lipocalins; Male; Mice; Middle Aged; Pilot Projects; Proto-Oncogene Proteins; Transcriptome; Transforming Growth Factor beta

Affecting more than 230,000,000 patients, diabetes mellitus is one of the most frequent metabolic disorders in developed countries. Among other complications, diabetic patients have an increased fracture risk and show delayed fracture healing. During the disease progression, these patients' blood glucose and insulin levels vary significantly. Thus, the aim of this study was to analyze the effects of glucose and insulin on primary human osteoblasts. Although, in the presence of insulin and glucose, proliferation of osteoblasts was increased (1.2- to 1.7-fold), their alkaline phosphatase activity and, consequently, production of mineralized matrix were significantly reduced down to 55 % as compared to control cells (p < 0.001). Interestingly, the observed effects were mainly due to stimulation with insulin. Increase in glucose did not alter osteoblasts' function significantly but further enhanced the effects of insulin. Expression of active and total transforming growth factor beta (TGF-β) was increased by glucose and insulin. Stimulation with both glucose and insulin induced gene expression changes (e.g., osteocalcin, Runx2, Satb2, or Stat1) comparable to treatment with recombinant TGF-β(1), further indicating osteoblasts' dysfunction. Inhibition of TGF-β signaling completely abolished the negative effects of glucose and insulin. In summary, glucose and insulin treatment causes osteoblast dysfunction, which is accompanied by an increased TGF-β expression. Blocking TGF-β signaling abrogates the functional loss observed in glucose- and insulin-treated osteoblasts, thus identifying TGF-β as a key regulator. Therefore, increased TGF-β expression during diabetes may be a feasible pathogenic mechanism underlying poor bone formation in uncontrolled diabetes mellitus.

Topics: Alkaline Phosphatase; Blood Glucose; Bone Resorption; Cell Proliferation; Diabetes Mellitus, Type 2; Disease Progression; Gene Expression Profiling; Gene Expression Regulation; Humans; Hyperinsulinism; In Vitro Techniques; Insulin; Osteoblasts; Osteogenesis; Recombinant Proteins; Transforming Growth Factor beta; Up-Regulation

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

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. To date, the molecular mechanisms of DN remain largely unclear. The present study aimed to identify and characterize novel proteins involved in the development of DN by a proteomic approach. Proteomic analysis revealed that 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase 2 (HMGCS2), the key enzyme in ketogenesis, was increased fourfold in the kidneys of type 2 diabetic db/db mice. Consistently, the activity of HMGCS2 in kidneys and 24-h urinary excretion of the ketone body β-hydroxybutyrate (β-HB) were significantly increased in db/db mice. Immunohistochemistry, immunofluorescence, and real-time PCR studies further demonstrated that HMGCS2 was highly expressed in renal glomeruli of db/db mice, with weak expression in the kidneys of control mice. Because filtered ketone bodies are mainly reabsorbed in the proximal tubules, we used RPTC cells, a rat proximal tubule cell line, to examine the effect of the increased level of ketone bodies. Treating cultured RPTC cells with 1 mM β-HB significantly induced transforming growth factor-β1 expression, with a marked increase in collagen I expression. β-HB treatment also resulted in a marked increase in vimentin protein expression and a significant reduction in E-cadherin protein levels, suggesting an enhanced epithelial-to-mesenchymal transition in RPTCs. Collectively, these findings demonstrate that diabetic kidneys exhibit excess ketogenic activity resulting from increased HMGCS2 expression. Enhanced ketone body production in the diabetic kidney may represent a novel mechanism involved in the pathogenesis of DN.

Topics: 3-Hydroxybutyric Acid; Animals; Blotting, Western; Cells, Cultured; Collagen Type I; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Epithelium; Fluorescent Antibody Technique; Hydroxymethylglutaryl-CoA Synthase; Immunohistochemistry; In Vitro Techniques; Ketone Bodies; Kidney; Kidney Glomerulus; Kidney Tubules, Proximal; Mesoderm; Mice; Mice, Inbred C57BL; Proteomics; Rats; RNA; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Transforming Growth Factor beta

The active type of coagulation factor X (factor Xa) activates various cell-types through protease-activated receptor 2 (PAR2). We previously reported that a factor Xa inhibitor could suppress Thy-1 nephritis. Considering that fibrin deposition is observed in diabetic nephropathy as well as in glomerulonephritis, this study examined the roles of the coagulation pathway and factor Xa in the development of diabetic nephropathy using type 2 diabetic model mice. Diabetic (db/db) and normoglycemic (m+/m+) mice were immunohistochemically evaluated for their expression/deposition of PAR2, transforming growth factor (TGF)-β, fibrin, extracellular matrix (ECM) proteins, and CD31 at week 20. Significantly greater numbers of PAR2-positive cells and larger amounts of fibronectin, and collagen IV depositions were observed in the glomeruli of db/db mice than those in m+/m+ mice. Next, expression of PAR2 versus deposition of collagen IV and fibronectin was compared between week 20 and week 30, and the number of PAR2-positive cells in the glomeruli decreased in contrast with the increased accumulation of ECM proteins. In an intervention study, fondaparinux, a factor Xa inhibitor, was subcutaneously administered for ten weeks from week 10 to 20. Fondaparinux treatment significantly suppressed urinary protein, glomerular hypertrophy, fibrin deposition, expression of connective tissue growth factor, and ECM proteins deposition together with CD31-positive capillaries. These results suggest that coagulation pathway and glomerular PAR2 expression are upregulated in the early phase of diabetes, together with the increase of profibrotic cytokines expression, ECM proteins deposition and CD-31-positive vessels. Factor Xa inhibition may ameliorate glomerular neoangiogenesis and ECM accumulation in diabetic nephropathy.

Topics: Animals; Anticoagulants; Blood Coagulation; Capillaries; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Extracellular Matrix Proteins; Factor Xa; Factor Xa Inhibitors; Fibrin; Fondaparinux; Hypertrophy; Kidney; Kidney Glomerulus; Male; Mice; Mice, Obese; Platelet Endothelial Cell Adhesion Molecule-1; Polysaccharides; Proteinuria; Receptor, PAR-2; Transforming Growth Factor beta; Up-Regulation

Wound healing (WH) impairment is a well-documented phenomenon in clinical and experimental diabetes. Sex hormones, in addition to a number of signaling pathways including transforming growth factor-β1 (TGF-β1)/Smads and TNF-α/NF-κB in macrophages and fibroblasts, appear to play a cardinal role in determining the rate and nature of WH. We hypothesized that a defect in resolution of inflammation and an enhancement in TNF-α/NF-κB activity induced by estrogen deficiency contribute to the impairment of TGF-β signaling and delayed WH in diabetes models. Goto-Kakizaki (GK) rats and full thickness excisional wounds were used as models for type 2 diabetes (T2D) and WH, respectively. Parameters related to the various stages of WH were assessed using histomorphometry, western blotting, real-time PCR, immunofluorescence microscopy and ELISA-based assays. Retarded re-epithelialization, suppressed angiogenesis, delayed wound closure, reduced estrogen level and heightened states of oxidative stress were characteristic features of T2D wounds. These abnormalities were associated with a defect in resolution of inflammation, shifts in macrophage phenotypes, increased β3-integrin expression, impaired wound TGF-β1 signaling (↓p-Smad2/↑Smad7) and enhanced TNF-α/NFκB activity. Human/rat dermal fibroblasts of T2D, compared to corresponding control values, displayed resistance to TGF-β-mediated responses including cell migration, myofibroblast formation and p-Smad2 generation. A pegylated form of soluble TNF receptor-1 (PEG-sTNF-RI) or estrogen replacement therapy significantly improved re-epithelialization and wound contraction, enhanced TGFβ/Smad signaling, and polarized the differentiation of macrophages toward an M2 or "alternatively" activated phenotype, while limiting secondary inflammatory-mediated injury. Our data suggest that reduced estrogen levels and enhanced TNF-α/NF-κB activity delayed WH in T2D by attenuating TGFβ/Smad signaling and impairing the resolution of inflammation; most of these defects were ameliorated with estrogen and/or PEG-sTNF-RI therapy.

Topics: Animals; Cell Line; Cell Movement; Diabetes Mellitus, Type 2; Estrogens; Female; Fibroblasts; Humans; Inflammation; Macrophages; NF-kappa B; Oxidative Stress; Rats; Rats, Wistar; Signal Transduction; Skin; Smad2 Protein; Smad7 Protein; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Wound Healing

To study the effect of Shengmai San ((see text) Pulse-activating Powder) in protecting myocardium in the rat of the type 2 diabetic cardiomyopathy (DCM) model.. The DCM rat model was established by combination of insulin resistance induced by a high-fat diet with intraperitoneal injection of high dose streptozotocin (50 mg/kg). And these rat models were randomly divided into three groups: a normal group (n = 12,one of them died), a model group (n = 15) and a Shengmai San group (treatment group, n = 15).The damage of the myocardium was assessed by electrocardiogram at the twelfth week after modeling, and the blood glucose, cholesterol and triglyceride levels were determined; the content of the left cardiac ventricle myocardial collagen was quantified by Masson staining test; the level of myocardial cell apoptosis was detected with TUNEL apoptosis detection kit; the damage extent of the myocardial sub-cellular structures was observed by electron microscopy; the expression levels of cardiac TSP-1 (Thrombospondin-1), TGF-beta1 (Transforming Growth F factor-beta) and TRB-3 (Tribbles homolog 3) proteins were detected by immunohistochemical method; the expression levels of cardiac TSP-1, A-TGF-beta1 and L-TGF-beta1 proteins were detected by Western blotting; and the expression levels of TSP-1 and TRB-3 mRNAs were detected by real-time quantitative PCR.. Compared with the control group, the blood glucose, cholesterol, triglycerides levels in both the model groups and the Shengmai San group were significantly decreased; the myocardial tissue was less damaged and the collagen content was reduced in the Shengmai San group; the myocardial sub-cellular structure was injured to a lesser extent; the expression levels of myocardial TSP-1, TGF-beta1, TRB-3, and TSP-1, A-TGF-beta1, L-TGF-beta1 and chymase were decreased, and the expression levels of TSP-1 mRNA and TRB-3 mRNA were decreased in both the model groups and the Shengmai San group (the latter was better),.. Shengmai San can inhibit myocardial fibrosis in the rat of diabetic cardiomyopathy, and significantly delay the formation of diabetic cardiomyopathy in hyperglycemia rats through multiple pathways.

Topics: Animals; Apoptosis; Blotting, Western; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Drug Combinations; Drugs, Chinese Herbal; Immunohistochemistry; Male; Myocardium; Polymerase Chain Reaction; Protein Kinases; Protein Serine-Threonine Kinases; Rats; Rats, Sprague-Dawley; Thrombospondin 1; Transforming Growth Factor beta; Transforming Growth Factor beta1

The pathogenesis of diabetic nephropathy, mainly characterized by macroalbuminuria, is still poorly understood, but it is reported that transforming growth factor-beta (TGF-beta) plays a key role. In vitro evidence suggests that administration of oxidized LDL (ox-LDL) can lead to upregulation of TGF-beta by human glomerular mesangial cells. This study aimed to evaluate the association between macroalbuminuria, ox-LDL, and TGF-beta in diabetic patients. A total of 77 type 2 diabetic patients with macroalbuminuria (albumin excretion rate: AER > or = 300 mg/24 h) and 66 patients with normoalbuminuria (AER < or = 30 mg/24 h) were recruited. Fasting blood samples were obtained and serum levels of ox-LDL and TGF-beta were determined. Ox-LDL and TGF-beta were significantly higher in patients with macroalbuminuria than in those with normoalbuminuria (98.93 + or - 3.99 vs. 72.45 + or - 2.48 U/l; P < 0.001 and 6.46 + or - 0.74 vs. 2.49 + or - 0.39 ng/ml; P < 0.001, respectively). In patients with macroalbuminuria, there was a significant correlation between Ox-LDL and TGF-beta (r = 0.376; P < 0.01). AER was significantly correlated to ox-LDL (r = 0.302; P < 0.05) and TGF-beta (r = 0.306; P < 0.05) in macroalbuminuric patients. This association remained significant after adjustment for potential confounders. Adjustment for TGF-beta (ox-LDL), attenuated the association of ox-LDL (TGF-beta) with AER. In conclusion, this study demonstrated the association of TGF-beta and ox-LDL with albuminuria in macroalbuminuric type 2 diabetic patients, and suggested that this relationship is highly mediated through the correlation between TGF-beta and ox-LDL.

Topics: Albuminuria; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Humans; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Transforming Growth Factor beta

Accumulating evidence suggests that alcohol, hepatitis C virus infection, steatosis with obesity, and insulin resistance are accompanied by iron overload states. Phlebotomy and oral iron chelators are effective treatments for these conditions and for hemochromatosis. However, the mechanisms by which iron depletion improves clinical factors remain unclear. We examined the effect of iron depletion in a model of type 2 diabetes, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Age-matched Long-Evans Tokushima Otsuka (LETO) rats were used as controls for all experiments. Iron restriction was performed by eliminating iron in the diet from 15 wk of age or by phlebotomy. Phlebotomy was commenced at 29 wk of age by removing 4 and 3 ml of blood from the tail vein every week in OLETF and LETO rats, respectively. Rats were euthanized at 43 wk of age, and detailed analyses were performed. The plasma ferritin concentration was markedly higher in OLETF rats and decreased in iron-deficient (ID) diet and phlebotomy rats. Hemoglobin A(1c) (Hb A(1c)) was decreased significantly in OLETF rats fed the ID diet and in the phlebotomy group. Increased levels of triglycerides, glucose, free fatty acids, and total cholesterol were found in ID OLETF rats. Plasma, liver, and pancreas lipid peroxidation and hepatic superoxide production decreased in both groups. Pancreatic fibrosis and insulin levels improved in both groups of OLETF rats. Pancreatic levels of peroxisome proliferator-activated receptor-beta/delta (PPARbeta/delta) ligands and hypoxia-inducible factor (HIF)-1alpha were decreased significantly in OLETF rats. These factors were normalized in both rats fed ID and phlebotomy groups of OLETF rats. In conclusion, iron depletion improved diabetic complications by inhibition of oxidative stress and TGFbeta signal pathways and the maintenance of pancreatic PPARbeta/delta and HIF-1alpha pathways.

Topics: Animals; Diabetes Mellitus, Type 2; Ferritins; Gene Expression; Glycated Hemoglobin; Hypoxia-Inducible Factor 1, alpha Subunit; Immunohistochemistry; Insulin; Iron; Iron Deficiencies; Liver; Male; Malondialdehyde; Oxidative Stress; Pancreas; PPAR delta; Rats; Rats, Inbred OLETF; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Superoxide Dismutase; Transforming Growth Factor beta

Addition of aliskiren, a direct renin inhibitor, to losartan provides additive reduction of urinary albumin excretion in type 2 diabetic patients. However, the detailed effect of aliskiren on type 2 diabetic nephropathy is still unknown. This study was undertaken to examine the efficacy of aliskiren and the combination of aliskiren with valsartan on type 2 diabetic nephropathy.. db/db mice were treated with aliskiren (3 mg/kg per day), valsartan (5 or 10 mg/kg per day), combined aliskiren (3 mg/kg per day) and valsartan (5 mg/kg per day), and hydralazine (80 mg/kg per day), for 6 weeks, and the protective effects against diabetic nephropathy were compared among each group.. Aliskiren significantly attenuated albuminuria and glomerular mesangial matrix expansion in db/db mice, which was associated with the improvement of the increased glomerular transforming growth factor-beta and type IV collagen expressions, the increased macrophage infiltration, and the decreased glomerular nephrin expression of db/db mice. These protective effects of aliskiren in db/db mice were attributed to the attenuation of p22(phox)-related nicotinamide adenine dinucleotide phosphate oxidase-induced superoxide. Addition of aliskiren to valsartan treatment provided more beneficial effects on all the above-mentioned parameters than valsartan monotherapy.. Aliskiren protected against type 2 diabetic nephropathy, through pleiotropic effects, and significantly enhanced the protective effects of valsartan against diabetic nephropathy in db/db mice.

Topics: Albuminuria; Amides; Animals; Collagen Type IV; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Synergism; Fumarates; Kidney Glomerulus; Losartan; Male; Mice; Mice, Inbred C57BL; Tetrazoles; Transforming Growth Factor beta; Valine; Valsartan

Loss of functional beta-cells is the primary cause of type 2 diabetes, so that there is an acute need to understand how beta-cell number and function are regulated in the adult under normal physiological conditions. Recent studies suggest that members of the transforming growth factor (TGF)-beta family regulate beta-cell function and glucose homeostasis. These factors are also likely to influence beta-cell proliferation and/or the incorporation of new beta-cells from progenitors in adults. Soluble TGFbeta antagonists also appear to have important roles in maintaining homeostasis, and the coordinated activity of TGFbeta family members is likely to regulate the differentiation and function of adult beta-cells, raising the possibility of developing new diabetes therapies based on TGFbeta agonists or antagonists.

Topics: Animals; Diabetes Mellitus, Type 2; Glucose; Homeostasis; Insulin-Secreting Cells; Mice; Signal Transduction; Transforming Growth Factor beta

Recent data indicate that loss-of-function mutation in the gene encoding the facilitative glucose transporter GLUT10 (SLC2A10) causes arterial tortuosity syndrome via upregulation of the TGF-β pathway in the arterial wall, a mechanism possibly causing vascular changes in diabetes.. We genotyped 10 single nucleotide polymorphisms and one microsatellite spanning 34 kb across the SLC2A10 gene in a prospective cohort of 372 diabetic patients. Their association with the development of peripheral arterial disease (PAD) in type 2 diabetic patients was analyzed.. At baseline, several common SNPs of SLC2A10 gene were associated with PAD in type 2 diabetic patients. A common haplotype was associated with higher risk of PAD in type 2 diabetic patients (haplotype frequency: 6.3%, P = 0.03; odds ratio [OR]: 14.5; 95% confidence interval [CI]: 1.3- 160.7) at baseline. Over an average follow-up period of 5.7 years, carriers with the risk-conferring haplotype were more likely to develop PAD (P = 0.007; hazard ratio: 6.78; 95% CI: 1.66- 27.6) than were non-carriers. These associations remained significant after adjustment for other risk factors of PAD.. Our data demonstrate that genetic polymorphism of the SLC2A10 gene is an independent risk factor for PAD in type 2 diabetes.

Topics: Aged; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Genotype; Glucose Transport Proteins, Facilitative; Haplotypes; Humans; Longitudinal Studies; Male; Middle Aged; Odds Ratio; Peripheral Vascular Diseases; Polymorphism, Single Nucleotide; Risk; Risk Factors; Transforming Growth Factor beta

Recent data suggest that aldosterone antagonists have beneficial effects on diabetic nephropathy. In this study, we investigated the dose-dependent effect of eplerenone and a combined treatment with eplerenone and enalapril compared with each drug alone on renal function in type II diabetic rats. To further explore the molecular mechanism of action of combination therapy, we also performed in vitro study.. The animals were divided into six groups as follows: normal control Long-Evans Tokushima Otsuka (LETO) rats, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, OLETF rats treated with low dose of eplerenone (50 mg/kg/day), OLETF rats treated with high dose of eplerenone (200 mg/kg/day), OLETF rats treated with enalapril (10 mg/kg/day) and OLETF rats treated with a combination of both drugs (eplerenone 200 mg/kg/day and enalapril 10 mg/kg/day) for 6 months.. Treatment of OLETF rats had no significant effect on body weight, kidney weight and blood glucose levels. However, urinary albumin excretion, glomerular filtration rate and glomerulosclerosis were significantly improved in the enalapril group and improvement was observed in a dose-dependent manner in the eplerenone groups; the most dramatic decreases were observed in the combination group. In accordance with these findings, renal expressions of TGF-beta1, type IV collagen and PAI-1 were also markedly decreased in the treatment groups, with the combined treatment providing the most significant level of improvement. In cultured mesangial cells, combined treatment resulted in an additive decrease in TGF-beta1, PAI-1 and collagen gene expressions and protein production induced by high glucose and aldosterone stimulation.. Aldosterone receptor antagonism provided additional benefits beyond blockade of the renin-angiotensin system in type II diabetic nephropathy.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Base Sequence; Collagen Type IV; Diabetes Mellitus, Type 2; Diabetic Nephropathies; DNA Primers; Dose-Response Relationship, Drug; Drug Therapy, Combination; Enalapril; Eplerenone; Extracellular Matrix Proteins; Gene Expression; Glomerular Filtration Rate; In Vitro Techniques; Male; Mesangial Cells; Mineralocorticoid Receptor Antagonists; Plasminogen Activator Inhibitor 1; Rats; Rats, Inbred OLETF; Renin-Angiotensin System; Spironolactone; Transforming Growth Factor beta; Transforming Growth Factor beta1

Recent in vitro evidence suggests that oxidized low-density lipoprotein (ox-LDL) stimulates the expression of transforming growth factor-beta (TGF-beta) by human glomerular epithelial cells. An elevated level of TGF-beta, which is a multifunctional growth cytokine, is also reported in diabetic patients. This study aimed to determine the association between ox-LDL and TGF-beta in healthy and type 2 diabetic participants. A total of 80 type 2 diabetic patients, who were referred to the outpatient diabetes clinic of a university general hospital, and 80 healthy controls matched for sex, age, and body mass index (BMI) were recruited. Fasting blood samples were obtained, and fasting plasma glucose, cholesterol, high-density lipoprotein-cholesterol (HDL-c), LDL-cholesterol, triglycerides, creatinine, HbA1C, ox-LDL, and TGF-beta were measured. Ox-LDL and TGF-beta were significantly greater in diabetic patients than healthy controls (72.66 +/- 3.11, 46.02 +/- 1.64, P < 0.001 and 4.75 +/- 0.43, 2.06 +/- 0.31, P < 0.001, respectively). Ox-LDL was significantly correlated to TGF-beta in diabetic patients (r = 0.318, P = 0.004). This significant association was not observed in healthy controls (r = 0.148, P = 0.191). In multivariate linear regression analysis after adjustment for age, sex, BMI, and creatinine, ox-LDL was a significant independent predictor of TGF-beta (beta = 0.308, P = 0.007). In conclusion, this study demonstrated that ox-LDL is significantly correlated to TGF-beta in type 2 diabetic patients.

Topics: Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Humans; Linear Models; Lipoproteins, LDL; Male; Middle Aged; Multivariate Analysis; Predictive Value of Tests; Risk Factors; Transforming Growth Factor beta

Pancreatic islet beta-cell dysfunction is a signature feature of Type 2 diabetes pathogenesis. Consequently, knowledge of signals that regulate beta-cell function is of immense clinical relevance. Transforming growth factor (TGF)-beta signaling plays a critical role in pancreatic development although the role of this pathway in the adult pancreas is obscure. Here, we define an important role of the TGF-beta pathway in regulation of insulin gene transcription and beta-cell function. We identify insulin as a TGF-beta target gene and show that the TGF-beta signaling effector Smad3 occupies the insulin gene promoter and represses insulin gene transcription. In contrast, Smad3 small interfering RNAs relieve insulin transcriptional repression and enhance insulin levels. Transduction of adenoviral Smad3 into primary human and non-human primate islets suppresses insulin content, whereas, dominant-negative Smad3 enhances insulin levels. Consistent with this, Smad3-deficient mice exhibit moderate hyperinsulinemia and mild hypoglycemia. Moreover, Smad3 deficiency results in improved glucose tolerance and enhanced glucose-stimulated insulin secretion in vivo. In ex vivo perifusion assays, Smad3-deficient islets exhibit improved glucose-stimulated insulin release. Interestingly, Smad3-deficient islets harbor an activated insulin-receptor signaling pathway and TGF-beta signaling regulates expression of genes involved in beta-cell function. Together, these studies emphasize TGF-beta/Smad3 signaling as an important regulator of insulin gene transcription and beta-cell function and suggest that components of the TGF-beta signaling pathway may be dysregulated in diabetes.

Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Glucose; Humans; Hyperinsulinism; Hypoglycemia; Insulin; Insulin-Secreting Cells; Mice; Mice, Knockout; Primates; Promoter Regions, Genetic; RNA, Small Interfering; Signal Transduction; Smad3 Protein; Transcription, Genetic; Transforming Growth Factor beta

Impaired wound healing is one of the most common complications associated with diabetes. Adiponectin is an abundant circulating adipocyte-derived cytokine that has beneficial effects on disorders accompanying diabetes. Herein we report that adiponectin has a regulatory effect on the growth and differentiation of HaCaT human keratinocyte cells. Furthermore, adiponectin regulated the expression of TGFbeta isoforms in keratinocytes in a dose-dependent manner, which implies that adiponectin modulates other types of cells related to wound repair via secretion of growth factors from keratinocytes. Moreover, TUNEL assay results revealed that adiponectin enhances apoptosis of keratinocytes. Taken together, the present results indicate that adiponectin has suppressive effects on the formation of hyperkeratosis commonly seen in patients with diabetic foot and its application may be beneficial for developing treatment for that disorder.

Topics: Adiponectin; Apoptosis; Cell Differentiation; Cell Line; Cell Proliferation; Diabetes Mellitus, Type 2; Diabetic Foot; Gene Expression; Humans; Keratinocytes; Transforming Growth Factor beta; Wound Healing

Activation of the thrombospondin-1 (TSP-1)-TGF-beta pathway by glucose and the relevance of TSP-1-dependent activation of TGF-beta for renal matrix expansion, renal fibrosis and sclerosis have previously been demonstrated by our group in in vivo and in vitro studies. Design and methods. We investigated renal biopsies (n = 40) and clinical data (n = 30) of patients with diabetic nephropathy. Ten kidneys without evidence of renal disease served as controls. Glomerular and cortical expression of TSP-1, p-smad2/3, fibrosis and glomerular sclerosis (PAS) were assessed by immunhistochemical staining and related with clinical data.. Glomerular (g) and cortical (c) TSP-1 were increased during diabetic nephropathy (g: 2.62 +/- 2.65; c: 4.5 +/- 4.2) compared to controls (g: 0.67 +/- 0.7; c: 1.5 +/- 1.2). P-smad2/3 was significantly increased (g: 16.7 +/- 12.9; c: 148.7 +/- 92.8) compared to controls (g: 7.1 +/- 3.6; c: 55 +/- 25; P < 0.05). TSP-1 was coexpressed with p-smad2/3 as an indicator of TGF-beta activation. TSP-1 correlated with enhanced tubulointerstitial p-smad2/3 positivity (r = 0.39 and r = 0.4, P < 0.05) and glomerular p-smad2/3 correlated with proteinuria (r = 0.35, P < 0.05).. In summary, the present study suggests a functional activity of the TSP-1/TGF-beta axis, especially in the tubulointerstitium of patients with diabetic nephropathy. The positive correlation of glomerular p-smad2/3 positivity with proteinuria further supports the importance of the TSP-1/TGF-beta system as a relevant mechanism for progression of human type-2 diabetic nephropathy.

Topics: Adult; Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fibrosis; Humans; Middle Aged; Proteinuria; Signal Transduction; Smad2 Protein; Smad3 Protein; Thrombospondin 1; Transforming Growth Factor beta

Chronic renal hypoxia is suspected to play a pathogenic role in the genesis of diabetic nephropathy (DN). Cobalt enhances the activity of the hypoxia-inducible factor (HIF), a key factor in the defence against hypoxia. Its long-term effect on DN is evaluated.. Cobalt chloride was given to hypertensive, type 2 diabetic rats with nephropathy (SHR/NDmcr-cp). Treatment was initiated at the age of 13 weeks and continued for 26 weeks.. Cobalt did not correct hypertension and metabolic abnormalities (obesity, hyperglycaemia and hyperlipidaemia) but reduced proteinuria as well as histological kidney injury. Cobalt upregulated renal HIF-1alpha and HIF-2alpha expression and increased the expression of HIF-regulated genes, including erythropoietin, vascular endothelial growth factor and heme oxygenase-1. The renal expression of transforming growth factor (TGF)-beta and connective tissue growth factor (CTGF) was significantly reduced by cobalt. The renal expression of NADPH oxidase, a marker of oxidative stress, and the renal content of pentosidine, a marker of advanced glycation, were also significantly reduced by cobalt.. Cobalt achieved renal protection independently of metabolic status and blood pressure. Its effect was attributed to the upregulation of HIF and HIF-regulated genes and to a mitigated advanced glycation and oxidative stress.

Topics: Animals; Antimutagenic Agents; Arginine; Basic Helix-Loop-Helix Transcription Factors; Blood Pressure; Blotting, Western; Chromatography, High Pressure Liquid; Cobalt; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Gene Expression; Glycation End Products, Advanced; Hypertension; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Immediate-Early Proteins; Insulin-Like Growth Factor Binding Proteins; Intercellular Signaling Peptides and Proteins; Kidney; Lysine; Male; NADPH Oxidases; Obesity; Oxidative Stress; Polymerase Chain Reaction; Rats; Rats, Inbred SHR; RNA, Messenger; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) is a key mediator in the pathogenesis of renal diseases. Betaglycan, also known as the type III TGF-beta receptor, regulates TGF-beta action by modulating its access to the type I and II receptors. Betaglycan potentiates TGF-beta; however, soluble betaglycan, which is produced by the shedding of the membrane-bound receptor, is a potent antagonist of TGF-beta. In the present work, we have used a recombinant form of soluble betaglycan (SBG) to prevent renal damage in genetically obese and diabetic db/db mice. Eight-wk-old db/db or nondiabetic (db/m) mice were injected intraperitoneally with 50 mug of SBG or vehicle alone three times a wk for 8 wk. The db/db mice that received vehicle presented albuminuria and increased serum creatinine, as well as glomerular mesangial matrix expansion. The db/db mice treated with SBG exhibited a reduction in serum creatinine, albuminuria, and structural renal damage. These effects were associated with lower kidney levels of mRNAs encoding TGF-beta1, TGF-beta2, TGF-beta3, collagen IV, collagen I, fibronectin, and serum glucocorticoid kinase as well as a reduction in the immunostaining of collagen IV and fibronectin. Our data indicate that SBG is a renoprotective agent that neutralized TGF-beta actions in this model of nephropathy. Because SBG has a high affinity for all TGF-beta isoforms, in particular TGF-beta2, it is found naturally in serum and tissues and its shedding may be regulated. We believe that SBG shall prove convenient for long-term treatment of kidney diseases and other pathologies in which TGF-beta plays a pathophysiological role.

Topics: Albuminuria; Animals; Collagen; Creatinine; Diabetes Mellitus, Type 2; Disease Progression; Down-Regulation; Fibronectins; Glomerular Mesangium; Immunohistochemistry; Kidney Diseases; Kidney Glomerulus; Male; Mice; Mice, Inbred C57BL; Polysaccharides; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tissue Distribution; Transforming Growth Factor beta

We tested the hypothesis that AMP-activated protein kinase (AMPK), an energy sensor, regulates diabetes-induced renal hypertrophy. In kidney glomerular epithelial cells, high glucose (30 mM), but not equimolar mannitol, stimulated de novo protein synthesis and induced hypertrophy in association with increased phosphorylation of eukaryotic initiation factor 4E binding protein 1 and decreased phosphorylation of eukaryotic elongation factor 2, regulatory events in mRNA translation. These high-glucose-induced changes in protein synthesis were phosphatidylinositol 3-kinase, Akt, and mammalian target of rapamycin (mTOR) dependent and transforming growth factor-beta independent. High glucose reduced AMPK alpha-subunit theronine (Thr) 172 phosphorylation, which required Akt activation. Changes in AMP and ATP content could not fully account for high-glucose-induced reductions in AMPK phosphorylation. Metformin and 5-aminoimidazole-4-carboxamide-1beta-riboside (AICAR) increased AMPK phosphorylation, inhibited high-glucose stimulation of protein synthesis, and prevented high-glucose-induced changes in phosphorylation of 4E binding protein 1 and eukaryotic elongation factor 2. Expression of kinase-inactive AMPK further increased high-glucose-induced protein synthesis. Renal hypertrophy in rats with Type 1 diabetes was associated with reduction in AMPK phosphorylation and increased mTOR activity. In diabetic rats, metformin and AICAR increased renal AMPK phosphorylation, reversed mTOR activation, and inhibited renal hypertrophy, without affecting hyperglycemia. AMPK is a newly identified regulator of renal hypertrophy in diabetes.

Topics: Aminoimidazole Carboxamide; AMP-Activated Protein Kinases; Animals; Carrier Proteins; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucose; Hypertrophy; Intracellular Signaling Peptides and Proteins; Kidney; Metformin; Multienzyme Complexes; Phosphoproteins; Protein Serine-Threonine Kinases; Rats; Ribonucleosides; Transforming Growth Factor beta

We investigated the effect of KIOM-79, 80% ethanolic extract of a new herbal prescription, on non-obese type 2 diabetic Goto-Kakizaki (GK) rats. The rats were treated orally with KIOM-79 (500 mg/kg body weight) once a day for 13 weeks to examine the long-term effects on hyperglycemia and glomerular histology as well as biochemical and functional abnormalities in kidney. As the results, we found that KIOM-79 reduced hyperglycemia (p<0.01), ameliorated insulin resistance (p<0.001), urinary protein excretion (p<0.01) and creatinine clearance (Ccr) (p<0.001), and inhibited glomerular AGE formation (p<0.001) in diabetic GK rats. We also found that KIOM-79 prevented the glomeruli enlargement, overexpression of type IV collagen (p<0.001), PKC protein (p<0.01), TGF-beta mRNA (p<0.05) and VEGF mRNA (p<0.05). Thus, based on our finding, KIOM-79 could reduce the hyperglycemia, and prevent or retard the development of diabetic nephropathy.

Topics: Administration, Oral; Animals; Blood Glucose; Collagen Type IV; Creatine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Administration Schedule; Fasting; Glycation End Products, Advanced; Herbal Medicine; Hypoglycemic Agents; Immunohistochemistry; Insulin; Insulin Resistance; Kidney Cortex; Male; Plant Extracts; Protein Kinase C; Proteinuria; Rats; Rats, Inbred Strains; RNA, Messenger; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

The increasing prevalence of nonalcoholic steatohepatitis (NASH) is due to the epidemic of obesity and type 2 diabetes, both of which are associated with insulin resistance.. To clarify the causal relationship between insulin resistance and the development of NASH, steatohepatitis was induced in obese diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) and nondiabetic control Long-Evans Tokushima Otsuka (LETO) rats by feeding them a methionine and choline-deficient (MCD) diet. Insulin sensitivity of the rats was altered by adding a high-fat (HF) diet or the peroxisomal-proliferator activated receptor-gamma agonist pioglitazone to the MCD diet.. The MCD diet-induced steatohepatitis was accelerated in OLETF rats after 8 weeks. Steatosis preceded inflammation, which led to fibrosis and the development of steatohepatitis. The hepatic gene expression for transforming growth factor-beta, alpha1 procollagen and plasminogen activator inhibitor-1 was up-regulated in OLETF rats compared with LETO rats. The MCD + HF diet further enhanced insulin resistance and led to rapid development of pre-cirrhosis in OLETF rats by increasing the triglyceride pool, activating stellate cells, and up-regulating gene expression for sterol regulatory element-binding protein-1c and fatty acid synthase in the liver. In contrast, pioglitazone attenuated the MCD diet-induced steatohepatitis in OLETF rats but not in LETO rats by reversing the underlying pathogenesis involved in this model through improvement of insulin resistance. These results confirm a link between insulin resistance and the development/progression of steatohepatitis, at least partly via up-regulation of genes for lipogenesis, inflammation, and fibrogenesis, in animal models.. Insulin resistance and/or diabetes may accelerate the entire pathologic spectrum of NASH.

Topics: Animal Feed; Animals; Choline; Collagen Type I; Collagen Type I, alpha 1 Chain; Diabetes Mellitus, Type 2; Dietary Fats; Disease Models, Animal; Fatty Liver; Hyperinsulinism; Hypoglycemic Agents; Insulin Resistance; Liver; Male; Methionine; Obesity; Pioglitazone; Plasminogen Activator Inhibitor 1; PPAR gamma; Rats; Rats, Inbred OLETF; Rats, Long-Evans; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Thiazolidinediones; Transforming Growth Factor beta; Up-Regulation

Increased extracellular matrix material is a pathological hallmark of diabetic nephropathy. In addition to collagens, a variety of non-collagenous glycoproteins such as fibronectin also accumulate in the kidney of diabetics. The effect of diabetes on degradative pathways, in particular those involving non-collagenous proteins, are relatively unexplored. In this study, we determined the expression of the major matrix metalloproteinase (MMP) responsible for degrading the non-collagenous matrix glycoprotein fibronectin. Furthermore, the modulation of these MMPs by advanced glycation end products (AGE), a key factor in the diabetic milieu, was explored. Exposure of mesangial cells to AGEs led to a significant reduction in MMP-7, but not MMP-3 or -10. MMP-7 expression was normalized by both aminoguanidine, an inhibitor of glycation product formation, or by a neutralizing anti-transforming growth factor-beta (TGF-beta) antibody. In streptozotocin-induced diabetic rats, the diminution in MMP-7 expression and excessive fibronectin accumulation were attenuated by aminoguanidine. Humans with type 2 diabetes and nephropathy displayed similar alterations in MMP-7 to their rodent counterparts. Our findings suggest that diminished expression of the glycoprotein-degrading enzyme, MMP-7, may play a role in fibronectin accumulation in the diabetic kidney in response to AGEs and/or TGF-beta.

Topics: Adult; Animals; Antibodies; Cells, Cultured; Culture Media, Conditioned; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Down-Regulation; Female; Fibronectins; Glycation End Products, Advanced; Glycosylation; Guanidines; Humans; Male; Matrix Metalloproteinase 10; Matrix Metalloproteinase 3; Matrix Metalloproteinase 7; Mesangial Cells; Middle Aged; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors; Transforming Growth Factor beta

The status of the patient's associated disease can generally affect the onset or healing of acquired reactive perforating collagenosis (ARPC). We treated eight cases of ARPC and noted that the patients had similar findings. However, it was not clear why ARPC developed in the patients with these diseases. Nevertheless, several factors related to the diseases associated with ARPC could affect the degeneration of collagen fibers or the production of dermal products. Some patients had diseases that were characterized by fibrosis and an increased amount of reticular fibers. Factors related to tissue remodeling might act not only in diseases associated with ARPC but also in ARPC itself.

Topics: Adolescent; Adult; Aged; Carcinoma, Hepatocellular; Collagen; Collagen Diseases; Diabetes Mellitus, Type 2; Female; Humans; Liver Cirrhosis; Liver Neoplasms; Male; Middle Aged; Pulmonary Fibrosis; Reticulin; Skin Diseases; Transforming Growth Factor beta

Hyperinsulinemia has been implicated in the development of diabetic nephropathy. In the present study we compared the renoprotective effects of the thiazolidinedione, pioglitazone (PGZ), to that of insulin in a hypertensive, obese, type II diabetic rat model. PGZ aggravated obesity and gave less glycemic control than insulin. However, renoprotection was markedly better with PZG compared to insulin as shown by lower proteinuria, improved renal function, and less histological evidence of diabetic glomerular and tubulointerstitial lesions. PZG and insulin both reduced renal accumulation of pentosidine and oxidative stress to a similar extent. In contrast, PGZ but not insulin suppressed enhanced transforming growth factor-beta (TGF-beta) expression. We further confirmed in cultured rat proximal tubular cells that insulin enhanced TGF-beta mRNA expression and protein production. Our results identify hyperinsulinemia and the attendant increase of TGF-beta expression as potential therapeutic targets in diabetes independent of glycemic control. This confirms prior clinical evidence that PZG provides renoprotection in obese, diabetic patients with nephropathy.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Glycation End Products, Advanced; Hyperinsulinism; Hypertension, Renal; Hypoglycemic Agents; Insulin; Kidney; Male; Obesity; Oxidative Stress; Pioglitazone; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; RNA, Messenger; Thiazolidinediones; Transforming Growth Factor beta

Aortic calcification is prevalent in type II diabetes (T2DM), enhancing morbidity and tracking metabolic syndrome parameters. Ldlr(-/-) mice fed high-fat "Westernized" diets (HFD) accumulate aortic calcium primarily in the tunica media, mediated via osteogenic morphogens and transcriptional programs that induce aortic alkaline phosphatase (ALP). Because elevated TNF-alpha is characteristic of obesity with T2DM, we examined contributions of this inflammatory cytokine.. HFD promoted obesity, hyperglycemia, and hyperlipidemia, and upregulated serum TNF-alpha in Ldlr(-/-) mice. Serum haptoglobin (inflammatory marker) was increased along with aortic expression of BMP2, Msx2, Wnt3a, and Wnt7a. Dosing with the TNF-alpha neutralizing antibody infliximab did not reduce obesity, hypercholesterolemia, or hyperglycemia; however, haptoglobin, aortic BMP2, Msx2, Wnt3a, and Wnt7a and aortic calcium accumulation were downregulated by infliximab. Mice with vascular TNF-alpha augmented by a transgene (SM22-TNFalphaTg) driven from the SM22 promoter upregulated aortic Msx2, Wnt3a, and Wnt7a. Furthermore, SM22-TNFalphaTg;TOPGAL mice exhibited greater aortic beta-galactosidase reporter staining versus TOPGAL sibs, indicating enhanced mural Wnt signaling. In aortic myofibroblast cultures, TNF-alpha upregulated Msx2, Wnt3a, Wnt7a, and ALP. ALP induction was inhibited by Dkk1, an antagonist of paracrine Wnt actions.. TNF-alpha promote aortic Msx2-Wnt programs that contribute to aortic calcium accumulation in T2DM.

Topics: Alkaline Phosphatase; Animals; Anti-Inflammatory Agents; Antibodies, Monoclonal; Aorta; Aortic Diseases; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Calcinosis; Cells, Cultured; Diabetes Mellitus, Type 2; Dietary Fats; Disease Models, Animal; DNA-Binding Proteins; Fibroblasts; Haptoglobins; Homeodomain Proteins; Inflammation; Infliximab; Intercellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Microfilament Proteins; Muscle Proteins; Promoter Regions, Genetic; Receptors, LDL; RNA, Messenger; Signal Transduction; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Wnt Proteins; Wnt3 Protein; Wnt3A Protein

Advanced diabetic nephropathy (DN) is difficult to address experimentally in mice because available models of DN lack global glomerulosclerosis and major tubulointerstitial pathology. Accelerating the development of DN in mice would be desirable for feasible experimental validation of potential targets that mediate the progression to late stage DN.. 6 week old male db/db mice underwent uninephrectomy and the development of nephropathy was compared to wild-type mice and sham-operated db/db mice.. Uninephrectomy at young age was associated with increased albuminuria and severe glomerulosclerosis in 37% of glomeruli at 24 weeks of age as compared to sham-operated db/db mice (8%). Uninephrectomy also increased the number of glomerular macrophages in db/db mice. The uninephrectomy-related acceleration of glomerular damage was associated with significant tubulointerstitial injury as indicated by an increase in indices of tubular cell damage, tubular dilatation, and expansion of interstitial volume. Uninephrectomy markedly increased the renal mRNA expression of Mcp-1/Ccl2, Tgf-beta, and collagen I.. Early uninephrectomy can accelerate the development of advanced DN in db/db mice which may be instrumental in the design of interventional studies that intend to focus on the molecular pathology of the progression to late stage DN.

Topics: Animals; Atrophy; Biomarkers; Chemokine CCL2; Collagen Type I; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Gene Expression; Kidney Glomerulus; Kidney Tubules; Male; Mice; Mice, Inbred C57BL; Nephrectomy; Nephritis, Interstitial; RNA, Messenger; Transforming Growth Factor beta

Rhein and angiotensin-converting enzyme inhibitor (ACEI) have been reported to prevent the progression of diabetic nephropathy (DN). We further explore the unknown ability to induce renal-protection of rhein and ACEI combined therapy in DN compared with the therapeutic effects of single treatment of them by using db/db mouse of type 2 diabetes model.. db/db and db/m mice, 8 weeks of age, were divided into five groups according to the following treatments: (A) db/m, given saline treatment; (B) db/db, given saline treatment; (C) db/db, given rhein treatment (150 mg/kg/day); (D) db/db, given benazepril treatment (10 mg/kg/day); (E) db/db, given rhein (150 mg/kg/day) with benazepril (10 mg/kg/day). Body weight, plasma glucose, plasma lipid and 24 h urinary albumin excretion levels were measured every 4 weeks. Morphometry of renal tissue and immunohistology of transforming growth factor-beta1 (TGF-beta) and fibronectin were determined for all groups at the end of the treatment.. It was found that after treatment urinary albumin excretion was reduced after 4 weeks treatment in group E and after 8 weeks treatment in groups C and D, when compared to group B (p<0.05). Plasma creatinine levels dropped significantly for group E, compared with the diabetic control group by the end of the treatment period. Furthermore, after the treatment body weight, plasma glucose, cholesterol, triglyceride and low density lipoprotein all decreased in groups C and E compared to group B (p<0.05). Histological morphometric analysis revealed that the whole glomerular area and extracellular matrix area was significantly reduced in groups C, D and E compared to group B, at 20 weeks of age, an effect most pronounced in group E. Using immunohistochemistry, the expression of fibronectin and TGF-beta1 in groups C, D and E was found to have decreased compared to group B, after 12 weeks treatment, again the effect being more pronounced in group E.. There appeared to be a similar renal protective effect of rhein compared with benazepril in diabetic nephropathy. A combined therapy may offer a more beneficial complementary effect on kidney injury in db/db mice, as reflected by urinary albumin excretion, renal function and histological changes. Our findings suggest that a therapeutic approach that combines rhein with ACEI provides a more effective therapy for DN than does either agent alone.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Anthraquinones; Benzazepines; Blood Glucose; Cholesterol; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Therapy, Combination; Enzyme Inhibitors; Fibronectins; Fluorescent Antibody Technique, Direct; Immunohistochemistry; Mice; Mice, Inbred C57BL; Random Allocation; Transforming Growth Factor beta; Triglycerides

Diabetic nephropathy is currently the most common cause of end-stage renal disease. Diabetic nephropathy patients, whether insulin dependent or not, develop fibrotic changes in glomeruli that manifest as overt nephropathy. Previously, we demonstrated that 5-chloro-2-{(1E)-3-[2-(4-methoxybenzoyl)-4-methyl-1H-pyrrol-1-yl]prop-1-en-1-yl}-N-(methylsulfonyl)benzamide (SMP-534) reduces extracellular matrix (ECM) production induced by transforming growth factor-beta (TGF-beta) in vitro and prevents the accumulation of ECM in glomeruli in rat Thy-1 nephritis models. In this study, we examined the long-term effects of SMP-534 on renal insufficiency and glomerulosclerosis in db/db mice, which are models of type 2 diabetes. A diet containing SMP-534 was given to the mice from the age of 9 to 25 wk, and blood and urine analysis were performed at 8, 17, and 25 wk. At the end of study, kidney tissues were analyzed histologically. Treatment with SMP-534 dose dependently suppressed the increase of urinary albumin and type IV collagen excretion in db/db mice. The renal histological analysis showed that SMP-534 dose dependently suppressed the increase of mesangial expansion in the kidney. In the immunohistological analysis, fibronectin and type IV collagen expression were lower in SMP-534-treated db/db mice compared with vehicle-treated db/db mice. This study suggested that SMP-534 ameliorated the increase of ECM production in kidney of db/db mice, possibly through the inhibition of TGF-beta action. Hence, antifibrotic agents such as SMP-534 might be a new therapeutic option for the treatment of diabetic nephropathy.

Topics: Administration, Oral; Albuminuria; Animal Feed; Animals; Benzamides; Collagen Type IV; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Dose-Response Relationship, Drug; Extracellular Matrix; Mice; Mice, Inbred Strains; Transforming Growth Factor beta

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

Diabetic nephropathy is the leading cause of end-stage renal disease. Dopamine receptors are involved in the regulation of renal hemodynamics and may play a role in diabetes-induced hyperfiltration. To test this hypothesis, we investigated the renal effect of a dopamine D3 receptor antagonist (D3-RA) in hypertensive type II diabetic SHR/N-cp rats. Lean and obese SHR/N-cp rats were randomly assigned to D3-RA, angiotensin-converting enzyme inhibitor (ACE-i), or D3-RA+ACE-i treatment or control conditions. Treated animals were given the D3-RA A-437203 (10 mg/kg/body weight (BW)/day) or the ACE-i trandolapril (0.3 mg/kg BW/day) or a combination of both. At 6 months following perfusion, fixed kidneys were analyzed by morphological and stereological methods. Indices of renal damage (glomerulosclerosis, glomerulosclerosis damage index (GSI), tubulointerstitial and vascular damage), glomerular geometry and functional variables such as urinary albumin excretion, glomerular filtration rate, blood pressure, blood chemistry and BW were determined. The GSI (score 0-4) was significantly higher (P<0.05) in untreated diabetic animals (1.62+/-0.3) compared to nondiabetic controls (0.4+/-0.2) and the treatment groups (D3-RA: 0.31+/-0.12; ACE-i: 0.29+/-0.1; combination treatment: 0.12+/-0.01). Urinary albumin excretion (mg/24 h) was higher in untreated diabetic controls (102+/-19) compared to nondiabetic controls (31+/-12) and the treatment groups (D3-RA: 44+/-15; ACE-i: 41+/-13; combination treatment: 15+/-8). Mean glomerular volume was higher in untreated diabetic animals compared to nondiabetic controls and to the treatment groups. Desmin expression, a marker of podocyte damage, was elevated in untreated diabetic controls and diminished in all treatment groups. These data suggest that in a model of type II diabetes, the dopamine D3-RA had a beneficial effect on renal morphology and albuminuria, which was comparable in magnitude to that of ACE-i treatment.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dopamine Antagonists; Drug Therapy, Combination; Endothelin-1; Gene Expression; Kidney; Kidney Diseases; Kidney Function Tests; Kidney Glomerulus; Male; Rats; Rats, Inbred SHR; Receptors, Dopamine D3; RNA, Messenger; Transforming Growth Factor beta

In type 2 diabetic nephropathy, there is no animal model which has been completely matched with humans. Advanced glycation end products (AGE) and transforming growth factor-beta (TGF-beta) are closely related to hyperglycaemia and their pathobiochemistry could explain diabetic nephropathy. The objective of the present study was to evaluate the KK-A(y)/Ta mouse as a suitable model for type 2 diabetic nephropathy including pathological changes and immunohistochemical analyses of AGE and TGF-beta, compared with the non-diabetic BALB/cA mouse.. The urinary albumin/creatinine ratio (ACR), body weight (BW), fasting and casual blood glucose, blood haemoglobin A(1c) (HbA(1c)), creatinine clearance (Ccr) and blood pressure were measured for phenotypic characterisation. The pathological changes of glomeruli were evaluated by light microscopy, immunofluorescence and electron microscopy. AGE and TGF-beta accumulation were evaluated by immunoperoxidase staining.. The mean levels of ACR, casual blood glucose, blood HbA(1c) and Ccr in KK-A(y)/Ta mice were higher than those in age-matched non-diabetic BALB/cA mice after 12 weeks of age. There were no significant changes in the levels of systemic blood pressure among all groups. The pathological changes of glomeruli in KK-A(y)/Ta mice were consistent with those in the early stage of human diabetic nephropathy. AGE and TGF-beta protein appeared to be localised in the glomerular mesangial matrices.. It appears that KK-A(y)/Ta mice, especially in terms of histopathological findings, are a suitable animal model for the early stage of type 2 diabetic nephropathy.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Glycation End Products, Advanced; Kidney Glomerulus; Male; Mice; Mice, Inbred BALB C; Transforming Growth Factor beta

This paper was aimed to investigate (1) the early marker of endothelial injury in type 2 diabetes, (2) the intrarenal hemodynamics and renal function, and (3) the therapeutic strategy aiming to restore renal function. Fifty patients (35 normoalbuminuric and 15 albuminuric type 2 diabetes) were examined. Blood was collected for determination of circulating vascular endothelial cells (CEC) and the serum was prepared for determination of transforming growth factor beta (TGFbeta), ratio of CEC/TGFbeta, and soluble vascular cell adhesion molecule. Intrarenal hemodynamics and renal function were also assessed. The results showed that increased number of circulating EC, elevated TGFbeta and depleted ratio of CEC/TGFbeta were significantly observed. Intrarenal hemodynamic study revealed a hemodynamic maladjustment characterized by preferential constriction of the efferent arteriole, intraglomerular hypertension and reduction in peritubular capillary flow. It was concluded that early marker of endothelial injury is reflected by increasing number of CEC. Such markers correlate with the glomerular endothelial dysfunction associated with hemodynamic maladjustment. Early detection of endothelial injury and appropriate correction of hemodynamic maladjustment by multidrug vasodilators can effectively restore renal function in type 2 diabetic nephropathy.

Topics: Adult; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelial Cells; Glomerular Filtration Rate; Humans; Magnesium; Middle Aged; Regression Analysis; Renal Circulation; Statistics, Nonparametric; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vasodilator Agents

One of the mechanisms involved in the progression of diabetic nephropathy, the most common cause of end-stage renal failure, is angiogenic phenomenon associated with the increase of angiogenic factors such as vascular endothelial growth factor (VEGF)-A and angiopoietin (Ang)-2, an antagonist of Ang-1. In the present study, we examined the therapeutic efficacy of 2-(8-hydroxy-6-methoxy-1-oxo-1H-2-benzopyran-3-yl) propionic acid (NM-3), a small molecule isocoumarin with antiangiogenic activity, using diabetic db/db mice, a model of obese type 2 diabetes. Increases in kidney weight, glomerular volume, creatinine clearance, urinary albumin excretion, total mesangial fraction, glomerular type IV collagen, glomerular endothelial area (CD31(+)), and monocyte/macrophage accumulation (F4/80(+)) observed in control db/db mice were significantly suppressed by daily intraperitoneal injection of NM-3 (100 mg/kg, for 8 weeks). Increases in renal expression of VEGF-A, Ang-2, fibrogenic factor transforming growth factor (TGF)-beta1, and chemokine monocyte chemoattractant protein-1 but not tumor necrosis factor-alpha were also inhibited by NM-3 in db/db mice. Furthermore, decreases of nephrin mRNA and protein levels in db/db mice were recovered by NM-3. In addition, treatment of db/db mice with NM-3 did not affect body weight, blood glucose, serum insulin, or food consumption. NM-3 significantly suppressed the increase of VEGF induced by high glucose in cultured podocytes and also suppressed the increase of VEGF and TGF-beta induced by high glucose in cultured mesangial cells. Taken together, these results demonstrate the potential use of NM-3 as a novel therapeutic agent for renal alterations in type 2 diabetes.

Topics: Angiogenesis Inhibitors; Animals; Chemokine CCL2; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Heart; Insulin; Interleukin-6; Isocoumarins; Kidney; Liver; Mice; Obesity; Organ Size; Placebos; Polymerase Chain Reaction; Transforming Growth Factor beta

The expression of TGF beta-inducible gene h3(beta ig-h3) has been used to assess the biological activity of TGF beta in the kidney. In this study, we investigated whether the urinary concentration of beta ig-h3 is associated with diabetic nephropathy in patients with Type 2 diabetes mellitus. We also evaluated the relationship between the urinary concentration of beta ig-3 and proteinuria and microalbuminuria (AER) in a normal healthy population and in Type 2 diabetes patients.. Four hundred and seventy-nine Type 2 diabetic patients without non-diabetic kidney diseases and 528 healthy control subjects were enrolled. The study subjects were divided into five groups: a non-diabetic healthy control group with normal ACR (n = 443), a non-diabetic healthy control group with microalbuminuria (n = 85), a normoalbuminuric diabetic group (n = 198), a microalbuminuric diabetic group (n = 155) and an overt proteinuria group (n = 126). Urinary levels of beta ig-h3 were measured by enzyme-linked immunosorbent assay.. (i) Urinary excretion of beta ig-h3 was significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage (25.02 +/- 8.84 vs. 18.67 +/- 6.56, P = 0.03). In diabetic patients, urinary beta ig-h3 levels increased significantly as diabetic nephropathy advanced (25.02 +/- 8.84 vs. 34.06 +/- 24.55 vs. 169.63 +/- 57.33, P < 0.001). (ii) Proteinuria was found to be significantly correlated with urinary beta ig-h3 (healthy control; r = 0.137, P = 0.019, diabetic patients; r = 0.604, P < 0.001). ACR was also found to be significantly related with urinary beta ig-h3 in diabetic patients (r = 0.383, P = 0.006). (iii) In diabetic patients, urinary beta ig-h3 was significantly related with systolic and diastolic blood pressure (systolic blood pressure: r = 0.436, P = 0.024; diastolic blood pressure, r = 0.365, P = 0.042), total cholesterol and HbA(1c) (cholesterol: r = 0.169, P = 0.03, HbA(1c); r = 0.387, P = 0.044). Logistic regression analyses showed that urinary beta ig-h3 was associated with a significant increase in the risk of microalbuminuria and proteinuria in diabetic patients.. Longitudinal monitoring of urinary beta ig-h3 may improve the likelihood of detecting diabetic nephropathy at an earlier stage and beta ig-h3 could be a sensitive marker of diabetic kidney disease progression.

Topics: Albuminuria; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix Proteins; Female; Humans; Male; Middle Aged; Proteinuria; Risk Factors; Transforming Growth Factor beta

Whether temporary angiotensin II (AngII) blockade at the prediabetic stage attenuates renal injury in type 2 diabetic OLETF rats later in life was investigated. OLETF rats were treated with an AT(1) receptor antagonist (olmesartan, 0.01% in food), angiotensin-converting enzyme inhibitor (temocapril, 0.01% in food), a combination of the two, or hydralazine (25 mg/kg per d) at the prediabetic stage (4 to 11 wk of age) and then monitored without further treatment until 50 wk of age. At 11 wk of age, blood glucose levels and urinary protein excretion (U(protein)V) were similar between OLETF and control LETO rats. However, OLETF rats showed higher kidney AngII contents and type IV collagen mRNA expression than LETO rats at this age. These decreased with olmesartan, temocapril, and a combination of these but not with hydralazine. At 50 wk of age, diabetic OLETF rats showed higher BP, U(protein)V, and intrarenal AngII levels than LETO rats. Temporary AngII blockade did not affect glucose metabolism or the development of hypertension in OLETF rats but significantly suppressed proteinuria and ameliorated glomerular injury. However, no parameters were affected by temporary hydralazine treatment. The present study demonstrated that intrarenal AngII and type IV collagen expression are already augmented long before diabetes becomes apparent in OLETF rats. Furthermore, temporary AngII blockade at the prediabetic stage attenuates the progression of renal injury in these animals. These data suggest that early AngII blockade could be an effective strategy for preventing the development of type 2 diabetic renal injury later in life.

Topics: Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Blood Glucose; Blood Pressure; Body Weight; Collagen; Connective Tissue Growth Factor; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Therapy, Combination; Hydralazine; Imidazoles; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Male; NADPH Oxidases; Olmesartan Medoxomil; Prediabetic State; Rats; Rats, Inbred OLETF; Receptors, Angiotensin; Renin; Tetrazoles; Thiazepines; Thiobarbituric Acid Reactive Substances; Transforming Growth Factor beta

In an effort to identify genetic polymorphisms in potential candidate genes for type 2 diabetes mellitus (T2DM), we have sequenced the transforming growth factor beta-induced gene (TGFBI), and examined the association with T2DM and diabetic phenotypes in a Korean T2DM study (775 T2DM patients and 316 normal controls). Twenty-eight polymorphisms were identified in TGFBI. Although no significant associations were detected with the risk of T2DM, one SNP in intron 16 (c.2011+137C>T) and one SNP in the 3' untranslated region (UTR) (c.2589T>G), showed significant association with the levels of insulin and body mass index (BMI) among nondiabetic controls. The lower insulin and BMI were observed in individuals who carry one or two copies of minor alleles than others. For example, the highest BMI (24.21 kg/m(2)) in individuals with homozygote major alleles (T) of c.2589T>G (n=99), the intermediate BMI (23.68 kg/m(2)) in individuals with heterozygote alleles (n=156), and the lowest BMI (22.69 kg/m(2)) in individuals with homozygote minor alleles (G) (n=57, P=0.005) were observed. The present study provides, for the first time, information about genetic polymorphisms in TGFBI and positive associations of those polymorphisms with levels of insulin and BMI in the Korean population.

Topics: 3' Untranslated Regions; Aged; Alleles; Amino Acid Substitution; Blood Glucose; Body Mass Index; Cholesterol; Cholesterol, HDL; Diabetes Mellitus, Type 2; Exons; Extracellular Matrix Proteins; Female; Genetic Predisposition to Disease; Genotype; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Introns; Korea; Male; Middle Aged; Mutation, Missense; Polymorphism, Genetic; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Risk; Transforming Growth Factor beta; Triglycerides; Waist-Hip Ratio

To search for a gene(s) conferring susceptibility to diabetic nephropathy (DN), we genotyped over 80,000 gene-based single nucleotide polymorphisms (SNPs) in Japanese patients and identified that the engulfment and cell motility 1 gene (ELMO1) was a likely candidate for conferring susceptibility to DN, in view of the significant association of an SNP in this gene with the disease (intron 18+9170, GG vs. GA+AA, chi(2) = 19.9, P = 0.000008; odds ratio 2.67, 95% CI 1.71-4.16). In situ hybridization (ISH) using the kidney of normal and diabetic mice revealed that ELMO1 expression was weakly detectable mainly in tubular and glomerular epithelial cells in normal mouse kidney and was clearly elevated in the kidney of diabetic mice. Subsequent in vitro analysis revealed that ELMO1 expression was elevated in cells cultured under high glucose conditions (25 mmol/l) compared with cells cultured under normal glucose conditions (5.5 mmol/l). Furthermore, we identified that the expression of extracellular matrix protein genes, such as type 1 collagen and fibronectin, were increased in cells that overexpress ELMO1, whereas the expression of matrix metalloproteinases was decreased. These results indicate that ELMO1 is a novel candidate gene that both confers susceptibility to DN and plays an important role in the development and progression of this disease.

Topics: Adaptor Proteins, Signal Transducing; Alleles; Animals; Base Sequence; COS Cells; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Extracellular Matrix Proteins; Gene Expression; Genetic Predisposition to Disease; Genetic Variation; Humans; In Situ Hybridization; Kidney; Matrix Metalloproteinases; Mice; Mice, Inbred NOD; Polymorphism, Single Nucleotide; Transforming Growth Factor beta; Transforming Growth Factor beta1

Oxidative stress and inflammatory cytokines such as monocyte chemoattractant protein 1 (MCP-1), TGF-beta, and IL-2 are supposed to play crucial roles in the pathogenesis of insulin resistance (IR). Tranilast is an anti-allergic drug which exerts anti-inflammatory and anti-angiogenesis effects through inhibition of expression of MCP-1, TGF-beta, and antigen-induced IL-2 lymphocyte responsiveness. It also possesses a certain antioxidant activity. Considering the above facts and in view of its safety, tranilast may prove invaluable in the treatment of IR.

Topics: Adipose Tissue; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Chemokine CCL2; Cytokines; Depression, Chemical; Diabetes Mellitus, Type 2; Gene Expression Regulation; Humans; Insulin Resistance; Intercellular Adhesion Molecule-1; Interleukin-2; Models, Biological; ortho-Aminobenzoates; Oxidative Stress; Transforming Growth Factor beta

End-stage renal disease caused by diabetes disproportionately affects patients of African origin. The biological mechanism(s) for this observation is unclear. Emerging data from cross-sectional studies suggest that increased oxidative stress and the cytokine, transforming growth factor beta(1), are associated with this phenomenon. Therefore, a pathway involving these factors could alter the vulnerability to renal disease and impact adversely on the rate of loss of renal function.. We assessed the relationship between renal function, oxidative stress, and transforming growth factor beta(1) in 58 patients with type 2 diabetes of African and Caucasian origin over 174 patient-years of follow-up. Oxidative stress was assessed by measuring plasma lipid hydroperoxide and vitamin E in the postprandial state. Creatinine clearance was calculated from the Cockcroft-Gault equation. Patients received standardized management of hypertension, hyperglycemia, and hypercholesterolemia. Data were adjusted by multiple regression analysis to account for potential confounders.. Lipid hydroperoxide was higher and vitamin E lower, while there was no difference in fasting transforming growth factor beta(1) between the African (N= 22) and Caucasian (N= 36) patients [5.1(1.2) vs. 4.3 (1.8) micromol/L; P= 0.02 and 29.8 (10.8) vs. 41.3(19.7) micromol/L; P= 0.02 and 6.33 (5.5) vs. 6.84 (3.9) ng/mL; P= 0.73], respectively. The mean (95% confidence interval) of the difference in creatinine clearance between the patients of African and Caucasian origin was -12.5 (-23.4 to -1.7) mL/min; P= 0.015 at baseline, the magnitude of which increased to -17.5 (-28.4 to -6.5) mL/min; P= 0.002 after 3 years. The fall in creatinine clearance from baseline among the patients of African origin was greater for lower levels of vitamin E (rho = 0.48; P= 0.03). Final plasma creatinine was significantly higher in the African patients compared with the Caucasian patients [109.0 (25.8) vs. 94.0 (20.0) micromol/L; P= 0.0017]. In regression analysis, vitamin E was a significant and independent predictor of plasma creatinine (t -3.17, P= 0.003).. In these patients with type 2 diabetes, vitamin E is a determinant of renal function, and may explain some of the racial differences in renal disease susceptibility that precedes the divergence in incidence of end-stage renal disease.

Topics: Aged; Black People; Blood Glucose; Blood Pressure; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Follow-Up Studies; Humans; Lipid Peroxides; Lipids; Male; Middle Aged; Oxidative Stress; Transforming Growth Factor beta; Transforming Growth Factor beta1; United Kingdom; Vitamin E; White People

Macrophage infiltration in kidney is one of the most important events for the progression of diabetic nephropathy. Mycophenolate mofetil (MMF), an anti-inflammatory agent, has been shown to suppress macrophage infiltration and to improve renal injury in streptozotocin-induced diabetic kidneys. We examined whether mizoribine, which acts through immunosuppressive mechanisms similar to MMF, inhibits progression of diabetic nephropathy in non-insulin-dependent diabetic rats.. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a non-insulin-dependent diabetic model, and Long-Evans Tokushima Otsuka (LETO) rats, a non-diabetic control, were studied at 35 weeks of age. OLETF rats were randomized to receive mizoribine (5 or 10 mg/kg) or normal saline for 8 weeks. Histological changes such as glomerulosclerosis and interstitial fibrosis and the number of ED1- and CD5-positive cells in the kidney were assessed. By using reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry, monocyte chemoattractant protein-1 (MCP-1), osteopontin (OPN) and transforming growth factor (TGF)-beta1 expression in the kidney was also analysed.. Urinary albumin excretion in OLETF rats increased compared with that in LETO rats. Administration of mizoribine suppressed urinary albumin excretion. Development of glomerulosclerosis, interstitial fibrosis and macrophage infiltration in the kidney was also inhibited by treatment with mizoribine. The expression of MCP-1, OPN and TGF-beta1 mRNA in untreated OLETF rats was significantly increased compared with that in LETO rats. By immunohistochemistry, increased expression of MCP-1, OPN and TGF-beta1 was found in the tubules and glomeruli of untreated OLETF rats. This expression was significantly suppressed by treatment with mizoribine.. Mizoribine inhibited renal macrophage accumulation and prevented the progression of glomerulosclerosis and interstitial fibrosis in non-insulin-dependent diabetic kidneys. In addition to standard treatments, anti-inflammatory agents may be useful for management of non-insulin-dependent diabetic nephropathy.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Chemokine CCL2; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fibrosis; Glomerulosclerosis, Focal Segmental; Immunoenzyme Techniques; IMP Dehydrogenase; Macrophages; Male; Nephritis, Interstitial; Osteopontin; Rats; Rats, Inbred OLETF; Rats, Long-Evans; Reverse Transcriptase Polymerase Chain Reaction; Ribonucleosides; RNA, Messenger; Sialoglycoproteins; Transforming Growth Factor beta; Transforming Growth Factor beta1

Diabetic kidney disease has been associated with the presence of lipid deposits, but the mechanisms for the lipid accumulation have not been fully determined. In the present study, we found that db/db mice on the FVB genetic background with loss-of-function mutation of the leptin receptor (FVB-Lepr(db) mice or FVBdb/db) develop severe diabetic nephropathy, including glomerulosclerosis, tubulointerstitial fibrosis, increased expression of type IV collagen and fibronectin, and proteinuria, which is associated with increased renal mRNA abundance of transforming growth factor-beta, plasminogen activator inhibitor-1, and vascular endothelial growth factor. Electron microscopy demonstrates increases in glomerular basement membrane thickness and foot process (podocyte) length. We found that there is a marked increase in neutral lipid deposits in glomeruli and tubules by oil red O staining and biochemical analysis for cholesterol and triglycerides. We also detected a significant increase in the renal expression of adipocyte differentiation-related protein (adipophilin), a marker of cytoplasmic lipid droplets. We examined the expression of sterol regulatory element-binding protein (SREBP)-1 and -2, transcriptional factors that play an important role in the regulation of fatty acid, triglyceride, and cholesterol synthesis. We found significant increases in SREBP-1 and -2 protein levels in nuclear extracts from the kidneys of FVBdb/db mice, with increases in the mRNA abundance of acetyl-CoA carboxylase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoA reductase, which mediates the increase in renal triglyceride and cholesterol content. Our results indicate that in FVBdb/db mice, renal triglyceride and cholesterol accumulation is mediated by increased activity of SREBP-1 and -2. Based on our previous results with transgenic mice overexpressing SREBP-1 in the kidney, we propose that increased expression of SREBPs plays an important role in causing renal lipid accumulation, glomerulosclerosis, tubulointerstitial fibrosis, and proteinuria in mice with type 2 diabetes.

Topics: Animals; CCAAT-Enhancer-Binding Proteins; Cell Nucleus; Cholesterol; Diabetes Mellitus, Type 2; Diabetic Nephropathies; DNA-Binding Proteins; Female; Gene Expression Regulation; Hyperlipidemias; Kidney; Lipid Metabolism; Mice; Mutation; Obesity; Plasminogen Activator Inhibitor 1; Proteinuria; Receptors, Cell Surface; Receptors, Leptin; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Sterol Regulatory Element Binding Protein 2; Transcription Factors; Transforming Growth Factor beta; Triglycerides; Vascular Endothelial Growth Factor A

Galectins are beta-galactoside-binding lectins that are involved in various biologic processes, such as apoptosis, cell proliferation, and cell-cycle regulation. Galectin-9 (Gal-9) was identified previously and demonstrated to have apoptotic potential to thymocytes in mice and activated CD8(+) T cells in nephrotoxic serum nephritis model. In this study, the effect of Gal-9 on G1-phase cell-cycle arrest, one of the hallmark pathologic changes in early diabetic nephropathy, was investigated. Eight-week-old male db/db mice received injections of recombinant Gal-9 or vehicle for 8 wk. The injection of Gal-9 into db/db mice significantly inhibited glomerular hypertrophy and mesangial matrix expansion and reduced urinary albumin excretion. Gal-9 reduced glomerular expression of TGF-beta1 and the number of p27(Kip1)- and p21(Cip1)-positive cells in glomeruli. Double staining with nephrin and type IV collagen revealed that podocytes were mainly positive for p27(Kip1). For further confirming the cell-cycle regulation by Gal-9, conditionally immortalized mouse podocyte cells were cultured under 5.5 and 25 mM d-glucose supplemented with Gal-9. Cell-cycle distribution analyses revealed that Gal-9 maintained further progression of cell cycle from the G1 phase. Gal-9 reversed the high-glucose-mediated upregulation of p27(Kip1) and p21(Cip1) and inhibited cell-cycle-dependent hypertrophy, i.e., reduced [(3)H]proline incorporation. The data suggest that Gal-9 plays a central role in inducing their successful progression from G1 to G2 phase by suppressing glomerular expression of TGF-beta1 and inhibition of cyclin-dependent kinase inhibitors. Gal-9 may give an impetus to develop new therapeutic tools targeted toward diabetic nephropathy.

Topics: Animals; Cell Culture Techniques; Cell Cycle; Diabetes Mellitus, Type 2; Disease Models, Animal; DNA Primers; Galectins; Glucose; Hypertrophy; Kidney Glomerulus; Male; Mice; Mice, Mutant Strains; Podocytes; Polymerase Chain Reaction; Recombinant Proteins; Transforming Growth Factor beta; Transforming Growth Factor beta1

Rats fed a high fat diet and given a low dose of streptozotocin (STZ) (35 mg/kg) develop type 2 diabetes with insulin resistance, hyperinsulinemia, moderate hyperglycemia, hyperlipidemia, and salt-sensitive hypertension. We postulated that rats with noninsulinopenic (type 2) diabetes develop lesions of diabetic nephropathy significantly more prominent than those seen in classic insulinopenic (type 1) diabetic rats.. Rats were fed regular chow or high fat diet (60% calories from fat and 70% animal fat). After 5 weeks, rats fed regular chow received vehicle (controls) or 55 mg/kg STZ (type 1 diabetes mellitus). Rats fed high fat diet received vehicle (high fat) or low dose STZ, 35 mg/kg (type 2 diabetes mellitus). Rats were sacrificed 14 weeks after STZ/vehicle injection.. Blood glucose, systolic blood pressure, and urinary protein excretion were significantly higher in both diabetes groups than in controls. Serum insulin levels (ng/mL) were higher in type 2 diabetes than in type 1 diabetes groups (0.49 +/- 0.12 vs. 0.07 +/- 0.07) (P= 0.01). Percentage of sclerosed glomeruli was significantly higher in type 2 diabetes group than in control and type 1 diabetes groups. Fibronectin expression was significantly increased in high fat, type 1 and type 2 diabetes groups compared to controls. The expression of type IV collagen, connective tissue growth factor (CTGF), and transforming growth factor-beta (TGF-beta) was significantly increased in high fat and type 2 diabetes groups compared to controls.. Rats fed a high fat diet and given a low dose of STZ developed diabetes (with normal/high insulin levels), hypertension, and proteinuria. Kidney lesions in this type 2 model appear to be more pronounced than in type 1 diabetic rats despite lower blood glucose levels and proteinuria. We present a nongenetic rat model of type 2 diabetes mellitus and nephropathy.

Topics: Animals; Blood Glucose; Blood Pressure; Body Weight; Collagen Type IV; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Glycated Hemoglobin; Immediate-Early Proteins; Insulin; Intercellular Signaling Peptides and Proteins; Kidney; Lipids; Male; Organ Size; Proteinuria; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Patients with type 2 diabetes and macroalbuminuria generally experience progressive glomerular filtration rate (GFR) decline despite angiotensin-converting enzyme inhibition (ACEI) and blood pressure (BP) control but this therapy generally stabilizes GFR in those without macroalbuminuria. Cigarette smoking exacerbates GFR decline in patients with type 2 diabetes and macroalbuminuria despite ACEI and BP control; whether this therapy prevents nephropathy progression in nonmacroalbuminuric type 2 diabetic smokers is unknown.. We determined the course of urine excretion of indices of renal injury that distinguished patients with type 2 diabetes with and without macroalbuminuria but with normal plasma creatinine who were prospectively followed 6 months while receiving ACEI and BP control. We compared this course in nonsmokers and smokers with normo-, micro-, and macroalbuminuria (n = 157) and in response to smoking cessation in a separate cohort (n = 80) with microalbuminuria.. Urine excretion of transforming growth factor beta-1 (UTGFbetaV) increased in macroalbuminuric but not in nonmacroalbuminuric nonsmokers and UTGFbetaV rate was higher in smokers than nonsmokers within each albuminuria group. In the separate microalbuminuric cohort, the rate of UTGFbetaV change for quitting smokers was not different from nonsmokers (0.093 versus -0.123 ng/g of creatine/week, P = not significant) but that for nonquitting smokers (0.970) was higher than nonsmokers (P = 0.017).. Patients with type 2 diabetes who are at high risk compared with low risk for nephropathy progression have progressive renal injury as measured by increasing UTGFbetaV. Cigarette smoking exacerbates renal injury in type 2 diabetes despite BP control and ACEI, but its cessation in those with microalbuminuria ameliorates the progressive renal injury caused by continued smoking.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Collagen Type IV; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Female; Follow-Up Studies; Glomerular Filtration Rate; Humans; Hypertension; Male; Middle Aged; Regression Analysis; Renal Insufficiency; Smoking; Smoking Cessation; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) has multiple functions including increasing extracellular matrix deposition in fibrosis. It functions through a complex family of cell surface receptors that mediate downstream signaling. We report here that a transmembrane heparan sulfate proteoglycan, syndecan-2 (S2), can regulate TGF-beta signaling. S2 protein increased in the renal interstitium in diabetes and regulated TGF-beta-mediated increased matrix deposition in vitro. Transfection of renal papillary fibroblasts with S2 or a S2 construct that has a truncated cytoplasmic domain (S2DeltaS) promoted TGF-beta binding and S2 core protein ectodomain directly bound TGF-beta. Transfection with S2 increased the amounts of type I and type II TGF-beta receptors (TbetaRI and TbetaRII), whereas S2DeltaS was much less effective. In contrast, S2DeltaS dramatically increased the level of type III TGF-beta receptor (TbetaRIII), betaglycan, whereas S2 resulted in a decrease. Syndecan-2 specifically co-immunoprecipitated with betaglycan but not with TbetaRI or TbetaRII. This is a novel mechanism of control of TGF-beta action that may be important in fibrosis.

Topics: Binding Sites; Diabetes Mellitus, Type 2; Humans; Membrane Glycoproteins; Protein Binding; Protein Structure, Tertiary; Proteoglycans; Signal Transduction; Syndecan-2; Transforming Growth Factor beta

We evaluated whether ramipril, one of long-acting ACEIs, has a direct effect on pancreas islets in animal model of type 2 diabetes. OLETF rats were treated with ramipril for 24 weeks. We assessed the body weight, glucose tolerance, and the amount of islet fibrosis. RT-PCR and Western blot analysis of transforming growth factor-beta with its downstream signals were performed from the pancreas. Ramipril treatment remarkably reduced weight gain and the area under the curve of glucose. Islet fibrosis and the expression of TGF-beta with its downstream signal molecules were significantly reduced in the pancreas of ramipril-treated group than in control and paired-feeding group. These beneficial effects of ramipril might be related to the downregulation of TGF-beta and its downstream signals in OLETF rats. To our knowledge, this is the first report suggesting the potential effect of ramipril on the prevention of islet destruction by fibrosis in the animal model of type 2 diabetes mellitus.

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Blotting, Western; Body Weight; Diabetes Mellitus, Type 2; Fibrosis; Glucose Tolerance Test; Insulin Resistance; Islets of Langerhans; Male; Ramipril; Rats; Rats, Inbred OLETF; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Transforming Growth Factor beta

Diabetic nephropathy (DN) is a frequent complication in patients with diabetes mellitus. To find improved intervention strategies in this disease, it is necessary to investigate the molecular mechanisms involved. To obtain more insight into processes that lead to DN, messenger RNA expression profiles of diabetic glomeruli and glomeruli from healthy individuals were compared.. Two morphologically normal kidneys and 2 kidneys from patients with DN were used for the study. Glomerular RNA was hybridized in duplicate on Human Genome U95Av2 Arrays (Affymetrix, Santa Clara, CA). Several transcripts were tested further in independent patient groups and at the protein level by immunohistochemistry.. Ninety-six genes were upregulated in diabetic glomeruli, whereas 519 genes were downregulated. The list of overexpressed genes in DN includes aquaporin 1, calpain 3, hyaluronoglucosidase, and platelet/endothelial cell adhesion molecule. The list of downregulated genes includes bone morphogenetic protein 2, vascular endothelial growth factor (VEGF), fibroblast growth factor 1, insulin-like growth factor binding protein 2, and nephrin. A decrease in VEGF and nephrin could be validated at the protein level and also at the RNA level in renal biopsy specimens from 5 additional patients with diabetes.. Results of oligonucleotide microarray analyses on control and diabetic glomeruli are presented and discussed in their relation to vascular damage, mesangial matrix expansion, proliferation, and proteinuria. Our findings suggest that progression of DN might result from diminished tissue repair capability.

Topics: Adult; Aged; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Gene Expression Profiling; Humans; Immunohistochemistry; Kidney Glomerulus; Male; Membrane Proteins; Middle Aged; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Proteins; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A

Transforming growth factor-beta (TGF-beta) is a pro-sclerotic growth factor implicated in the pathogenesis of diabetic nephropathy. betaig-h3 is an extracellular matrix protein which is induced in many cells by TGF-beta. This study examined urinary betaig-h3 excretion in diabetic patients with elevated urinary albumin excretion and the clinical application of urinary betaig-h3 as a marker of diabetic nephropathy. Urinary and serum betaig-h3 levels were determined by enzyme-linked immunosorbent assay in 163 type 2 diabetic patients and 101 healthy control subjects of comparable age and weight. The ratio of urinary betaig-h3 and TGF-beta to creatinine was analyzed in patients with different degree of nephropathy. The betaig-h3 to creatinine ratio in urine was elevated in all groups of type 2 diabetics with normoalbuminuria (101.6 +/- 9.27), microalbuminuria (120.2 +/- 14.48), and overt proteinuria (146.3 +/- 16.34), when compared with control subjects (64.8 +/- 7.14) (P < 0.01). There was a positive correlation between urinary betaig-h3 and TGF-beta excretion rate and a positive correlation between urinary betaig-h3 and albumin excretion rate (AER). These data show that urinary levels of betaig-h3 are elevated in type 2 diabetic patients with nephropathy and may be used as a marker of diabetic nephropathy.

Topics: Albuminuria; Biomarkers; Blood Glucose; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Extracellular Matrix Proteins; Female; Humans; Insulin; Male; Middle Aged; Reference Values; Transforming Growth Factor beta

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors that are related to retinoid, steroid and thyroid hormone receptors. The PPAR subfamily comprises of three members, PPAR-alpha, PPAR-beta and PPAR-gamma. There is good evidence that ligands of PPAR-gamma, including certain thiazolinediones, reduce myocardial tissue injury and infarct size. The use of PPAR-gamma agonists in the treatment of heart failure is, however, controversial.

Topics: Animals; Chemokine CCL2; Diabetes Mellitus, Type 2; Disease Models, Animal; Heart Diseases; Humans; Hypoglycemic Agents; Ligands; Mice; Myocardial Infarction; Pioglitazone; PPAR gamma; Rats; Thiazolidinediones; Transforming Growth Factor beta; Treatment Outcome; Tumor Necrosis Factor-alpha

We examined the effects of early treatment with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor pravastatin on the progression of glucose intolerance and cardiovascular remodeling in a model of spontaneously developing type II diabetes mellitus (DM), the Otsuka Long-Evans Tokushima Fatty (OLETF) rats.. Clinical trials showed that pravastatin prevented new-onset DM in hypercholesterolemic patients, and that it was effective in prevention of cardiovascular events in diabetics.. The OLETF rats were treated with pravastatin (100 mg/kg/day) from 5 weeks of age and compared with age-matched untreated OLETF rats and normal Long-Evans Tokushima Otsuka (LETO) rats on serial oral glucose tolerance tests (OGTT) and Doppler echocardiography and on histopathological/biochemical analyses of the heart at 30 weeks.. The OGTT revealed that 40% and 89% of untreated OLETF rats were diabetic at 20 and 30 weeks, respectively, but 0% and only 30%, respectively, were diabetic in the treated OLETF. Left ventricular diastolic function was found impaired from 20 weeks in untreated OLETF but remained normal in the treated-OLETF. The wall-to-lumen ratio and perivascular fibrosis of coronary arteries were increased in untreated-OLETF but were limited in the treated-OLETF at 30 weeks. Moreover, cardiac expressions of a fibrogenic growth factor, transforming growth factor-beta1 (TGF-beta1), and a proinflammatory chemokine, monocyte chemoattractant protein-1 (MCP-1), were increased in untreated-OLETF. However, in the treated-OLETF, overexpressions of TGF-beta1 and MCP-1 were attenuated, which was associated with overexpression of endothelial nitric oxide synthase (eNOS) (2.5-fold of control LETO).. Early pravastatin treatment prevented cardiovascular remodeling in the spontaneous DM model by retarding the progression of glucose intolerance, overexpressing cardiac eNOS, and inhibiting overexpressions of fibrogenic/proinflammatory cytokines.

Topics: Animals; Blood Glucose; Chemokine CCL2; Cholesterol; Diabetes Mellitus, Type 2; Disease Models, Animal; DNA Primers; Glucose Tolerance Test; Hydroxymethylglutaryl CoA Reductases; Immunohistochemistry; Insulin; Leptin; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Pravastatin; Rats; Rats, Inbred OLETF; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Triglycerides; Tumor Necrosis Factor-alpha; Ventricular Remodeling

The majority of the presentations a the conference were on three highly sought-after targets for type 2 diabetes mellitus, namely PTP1B, PPARs and DPP-IV, reflecting the current focus and trend in the industry. A couple of novel targets were discussed, including the potential of myostatin as a type 2 diabetes mellitus target and a novel GPCR target. While small molecules were dominant, several biological-based approaches were covered: antibody therapeutics and oligonucleotide-based approaches (ASO and siRNA). In searching for small-molecule leads, structure-based rational design and focused combination chemistry appear to produce better results than a random high-throughput approach over the entire chemical library. The biggest challenges for diabetes and obesity drugs remain similar to those mentioned in previous meetings: increasing specificity to reduce side effects and maintaining long-term effect while maintaining or increasing efficacy. Due to the tremendous interest of the pharmaceutical industry in metabolic disease drug development, our knowledge of food intake and metabolism regulation has increased exponentially. Overall, the prospect of better drugs for, and better control of, type 2 diabetes mellitus and obesity is promising.

Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Delivery Systems; Drug Design; Humans; Insulin; Protease Inhibitors; Research; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) mediates the excess accumulation of extracellular matrix in the diabetic kidney. Smad family proteins have been identified as signal transducers for the TGF-beta superfamily. We sought to characterize the role of Smad proteins in mediating TGF-beta responses in the development of diabetic nephropathy.. We evaluated the time course of TGF-beta1 fibronectin, Smad2 and Smad3 protein expression and Smad3 activation in glomeruli from spontaneously diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats, using immunohistochemistry and Western blot analysis.. The glomeruli of diabetic OLETF rats showed not only accelerated activation of Smad3, but also enhanced protein expression of Smad2 and Smad3, which occurred in parallel to the increased expression of TGF-beta and fibronectin compared with glomeruli of control, Long-Evans Tokushima Otsuka (LETO) rats at 30 weeks of age. No differences were found in TGF-beta1 fibronectin, Smad2 and Smad3 protein expression and Smad3 activation in glomeruli between the two strains at 12 weeks of age when OLETF rats were not diabetic.. The enhancement of Smad protein expression and activation may be involved in the TGF-beta signaling cascade that plays an important role in the development of diabetic nephropathy through progressive expansion of the mesangial matrix.

Topics: Animals; Blotting, Western; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Gene Expression Profiling; Immunohistochemistry; Kidney Glomerulus; Male; Rats; Rats, Inbred OLETF; Signal Transduction; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta; Transforming Growth Factor beta1

Abundant evidence suggests that cytokines involve in the pathogenesis of latent autoimmune diabetes of adults (LADA). This is a slowly progressive form of type 1 diabetes, which is initially diagnosed as type 2 diabetes. In this study, healthy individuals LADA and type 2 diabetic patients were genotyped for IL-6-174G/C, TNF-alpha-308A/G, TGF-beta1-codon10T/C, TGF-beta1-codon25G/C, IL-10-1082A/G, IL-10-819T/C, IL-10-592A/C gene polymorphisms, by sequence-specific-primer polymerase chain reaction methodology. A significant difference in the frequencies of -1082A/G IL-10 alleles was observed, with the -1082*A allele (known to be associated with low IL-10 production), predominating in LADA diabetics than type 2 diabetics (p=0.036). No significant differences of genotypes, phenotypes, or haplotype frequencies in the remaining cytokine polymorphisms were observed. Analysis of allele combinations revealed a significant involvement of the low and high in vitro production IL-10 alleles in the development of LADA and type 2 diabetes, respectively. These results suggest that the G/A mutation at position -1082 of IL-10 promoter gene region might be one of the factors participating to the pathogenesis of LADA diabetes and that identification of cytokine gene polymorphisms might contribute to the characterization of the different types of diabetes mellitus.

Topics: Adult; Cytokines; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Genotype; Haplotypes; Humans; Interleukin-10; Interleukin-6; Phenotype; Polymerase Chain Reaction; Polymorphism, Genetic; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Osteopontin (OPN) mediates progressive renal injury in various renal diseases by attracting macrophages, and its expression is regulated by the renin-angiotensin system (RAS). We studied the association between OPN expression and tubulointerstitial injury, and investigated the effect of ramipril on OPN expression in an animal model of non-insulin-dependent diabetes mellitus (NIDDM): Otsuka Long-Evans Tokushima Fatty (OLETF) rats.. Control (Long-Evans Tokushima Otsuka, LETO) and diabetic (OLETF) rats were treated with ramipril (3 mg/kg in drinking water) or vehicle for nine months, starting at 20 weeks of age. Systolic blood pressure, body weight, urinary protein excretion and oral glucose tolerance tests (OGTT) were monitored periodically. Renal function, histology (glomerulosclerosis, tubulointerstitial fibrosis, and ED-1-positive cells as a measure of macrophage infiltration), and expressions of OPN and transforming growth factor-beta1 (TGF-beta1) were evaluated at the end of the study.. Compared with the LETO rats, OLETF rats showed declines in creatinine clearance rate, increases in urinary protein excretion and systolic blood pressure, and development of glomerulosclerosis, tubulointerstitial fibrosis, and inflammatory cell infiltration (all P < 0.05). Blocking angiotensin II with ramipril significantly improved all of these parameters (all P < 0.01). At the molecular level, expressions of OPN and TGF-beta1 were up-regulated in the OLETF rats, and were markedly suppressed following ramipril treatment. The sites of strong OPN mRNA and protein expressions were localized to areas of renal injury. Of note, the expression of OPN mRNA was strongly correlated with the number of ED-1-positive cells (r = 0.560, P = 0.01) and the tubulointerstitial fibrosis score (r = 0.500, P < 0.05).. Up-regulation of OPN expression may play a role in tubulointerstitial injury associated with diabetic nephropathy, and blockade of the RAS by ramipril may confer renoprotection by decreasing OPN expression in non-insulin-dependent diabetic nephropathy.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Administration Schedule; Ectodysplasins; Kidney; Macrophages; Male; Membrane Proteins; Nephritis, Interstitial; Osteopontin; Ramipril; Rats; Rats, Inbred OLETF; Rats, Long-Evans; RNA, Messenger; Sialoglycoproteins; Transforming Growth Factor beta; Transforming Growth Factor beta1

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

Although it is known that diabetic nephropathy is accelerated by hypertension, the mechanisms involved in this process are not clear. In this study we aimed to clarify these mechanisms using male Wistar fatty rats (WFR) as a type 2 diabetic model and male Wistar lean rats (WLR) as a control. Each group was fed a normal or high sodium diet from the age of 6 to 14 weeks. We determined the blood pressure and urinary albumin excretion (UAE). At the end of the study, the expressions of mitogen-activated protein kinases (MAPK) and transforming growth factor-beta1 (TGF-beta1) were examined in the isolated glomeruli by Western blot analysis, and the number of glomerular lesions was determined by conventional histology. High sodium load caused hypertension and a marked increase in UAE in the WFR but not in the WLR. Glomerular volume was increased in the hypertensive WFR. There was no difference among the four groups in the expression of c-Jun-NH2-terminal kinase (JNK). In contrast, the expressions of extracellular signal-regulated kinase 1/2 (ERK1/2) and its upstream regulator, MAPK/ERK kinase 1 (MEK1), were augmented in the hypertensive WFR. Expression of p38 MAPK was increased in the normotensive WFR, and further enhanced in the hypertensive WFR. Moreover, administration of high sodium load to WFR augmented the expression of TGF-beta1. In conclusion, systemic hypertension in WFR accelerates the diabetic nephropathy in type 2 diabetes via MEK-ERK and p38 MAPK cascades. TGF-beta1 is also involved in this mechanism.

Topics: Albuminuria; Animals; Blotting, Western; Body Weight; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Hemodynamics; Hypertension; Kidney; Kidney Glomerulus; Male; Mitogen-Activated Protein Kinases; Organ Size; p38 Mitogen-Activated Protein Kinases; Proto-Oncogene Proteins c-jun; Rats; Rats, Wistar; Sodium; Transforming Growth Factor beta

We have recently described an impaired proliferative response of CD4(+) T-cells to primary antigens in patients with insulin-dependent diabetes mellitus (IDDM) [Clin. Immunol. 103 (2002) 249]. In order to further investigate possible mechanisms underlying this impairment, several factors known to be involved in the down-regulation of the immune response both at the level of APCs and CD4(+) T-cells were investigated: Monocyte-derived dendritic cells (MDDC) from IDDM patients were shown to express elevated amounts of CD86 (B7.2) (p=0.003) and reduced amounts of the adhesion molecule CD54 (ICAM-1) (p=0.03) on their cell surface compared to age-matched healthy controls and patients with non-insulin-dependent diabetes mellitus (NIDDM) as well as decreased SDS-PAGE stability of HLA-DQ and -DR peptide complexes directly isolated from the IDDM patients' peripheral blood mononuclear cells (PBMCs). Expression of CTLA-4 (CD152), known to be involved in the down-regulation of the immune response, was shown to be increased on CD4(+) T-cells from IDDM patients after exposure to the primary antigen KLH (keyhole limpet hemocyanin) presented by MDDC (p=0.0047). Likewise, purified CD4(+) T-cells from IDDM patients produced elevated levels of the cytokine TGF-beta1 after stimulation with immobilized monoclonal antibodies directed against CD3 and CD28 (p=0.014). When monocytes from IDDM patients were stimulated with lipopolysaccharide (LPS), an increased tendency to produce the inhibitory cytokine interleukin (IL)-10 (p=0.007) and the acute phase cytokine IL-6 (p=0.044) was observed, whereas the concentrations of tumor necrosis factor (TNF)-alpha, IL-1beta, and IL-12 were comparable to controls. Taken together, our data suggest that a deviation in the expression of certain molecules known to be involved in the peripheral control of the immune response is present in IDDM patients and is underlying the observed impairment of the primary immune response.

Topics: Abatacept; Adult; Antibodies, Monoclonal; Antigens, CD; Antigens, Differentiation; B7-2 Antigen; CD28 Antigens; CD3 Complex; CD4-Positive T-Lymphocytes; Cells, Cultured; CTLA-4 Antigen; Cytokines; Dendritic Cells; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Electrophoresis, Polyacrylamide Gel; Female; HLA-DQ Antigens; HLA-DR Antigens; Humans; Immunoconjugates; Intercellular Adhesion Molecule-1; Lipopolysaccharides; Lymphocyte Activation; Male; Membrane Glycoproteins; Middle Aged; Monocytes; Transforming Growth Factor beta

TSC-22 is a leucine zipper transcriptional factor and expression of the TSC-22 gene is highly induced by TGF-beta treatment. We estimated the frequency of the -396 A/G polymorphism of the TSC-22 gene with an Alu I-Restriction fragment length polymorphism (RFLP) method in 498 Japanese subjects with type 2 diabetes mellitus. We also determined the promoter activity. The diabetic patients with the AA genotype had a significantly higher incidence of the diabetic nephropathy (vs. the AG genotype, P<0.05, odds ratio: 1.95; 95% confidence intervals 1.14-3.33). There was no significant difference in the promoter activity between the fragments with -396A and -396G. These findings suggest that the TSC-22 gene (-396) A allele is associated with an increasing risk of the diabetic nephropathy.

Topics: Cell Line, Tumor; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Genotype; Humans; Logistic Models; Luciferases; Male; Middle Aged; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Promoter Regions, Genetic; Repressor Proteins; Transcription Factors; Transforming Growth Factor beta

Coronary remodeling based on collagen abnormalities in diabetes might be associated with potential interactions between the matrix metalloproteinase (MMP) system, which regulates extracellular matrix turnover, and the fibrinolytic system, which is involved in the fibrin degradation process. We characterized the profiles of the MMP and fibrinolytic systems in insulin-resistant diabetic rat hearts.. By immunohistochemistry and in situ hybridization, transforming growth factor-beta1 (TGF-beta1) expression increased in coronary vessels, the perivascular area, and cardiomyocytes in diabetic rat hearts. Increased expression of plasminogen activator inhibitor-1 (PAI-1) in coronary vessels and the perivascular area was evident in diabetic hearts. In contrast, diabetic hearts exhibited reduced activity and expression of MMP-2 and decreased expression of membrane type-1 MMP (MT1-MMP). Both intravascular and extravascular collagen type I and III immunoreactivity and fibrin deposition were seen in diabetic coronary vessels. These alterations were reversed to nondiabetic levels by the angiotensin II type 1 receptor blocker candesartan, which prevented the development of perivascular fibrosis observed after Masson's trichrome staining.. In addition to upregulation of PAI-1, downregulation of MMP-2 and MT1-MMP might play a crucial role in coronary matrix remodeling in insulin-resistant diabetes. These molecules appear to be regulated by angiotensin II via stimulation of TGF-beta1.

Topics: Angiotensin II; Animals; Collagen Type I; Collagen Type III; Coronary Vessels; Diabetes Mellitus, Type 2; Down-Regulation; Fibrin; Fibrosis; Insulin Resistance; Matrix Metalloproteinase 2; Matrix Metalloproteinases; Rats; Rats, Inbred OLETF; Receptor, Melatonin, MT1; Transforming Growth Factor beta

The pathomechanisms that cause renal damage in diabetes have not been completely clarified. Treatment with angiotensin-converting enzyme inhibitors (ACE-i) is highly effective but fails to completely prevent end-stage renal disease. The effects of ET(A)-receptor blockers (ET(A)-RB) on renal damage are controversial and have rarely been investigated in type 2 diabetes. We compared the influence of the selective ET(A)-RB LU135252 and the ACE-i Trandolapril on renal structure in the SHR/N-cp rat model of type 2 diabetes. Three-month-old male SHR/N-cp rats were left untreated or received daily either Trandolapril or LU135252. The experiment was terminated after 6 months. The glomerulosclerosis index; tubulointerstitial damage index; and glomerular geometry, glomerular cell number, and capillary density were investigated. Proliferating cell nuclear antigen and desmin expression of podocytes, renal mRNA expression of endothelin (ET-1) and transforming growth factor-beta, blood pressure, and urine albumin excretion were measured. The glomerulosclerosis index was significantly higher in untreated diabetic animals than in the groups that were treated with ACE-i and ET(A)-RB. There were analogous changes in tubulointerstitial damage index. Treatment with either substance comparably lowered urinary albumin excretion in diabetic SHR/N-cp. Podocyte and endothelial cell numbers per glomerulus decreased in untreated diabetic animals; this was prevented by the ACE-i but not by the ET(A)-RB. Glomerular capillary length density was lower in SHR/N-cp, and this was normalized by ACE-i only. Increased expression of desmin and proliferating cell nuclear antigen expression of podocytes in the SHR/N-cp was abrogated by ACE-i but not by ET(A)-RB. Treatment with ACE-i or ET(A)-receptor antagonist resulted in less structural and functional alterations, but the ET(A)-RB was inferior to the ACE-i. This is particularly the case for podocyte changes pointing to angiotensin II-dependent pathomechanisms.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Immunohistochemistry; Indoles; Kidney; Male; Phenylpropionates; Proliferating Cell Nuclear Antigen; Pyrimidines; Rats; RNA, Messenger; Transforming Growth Factor beta

Hypertension is the main risk factor for the progression of kidney damage in diabetes mellitus. The aim of the present work is to compare the effect of the treatment with irbesartan (IRBE) and omapatrilat (OMA), in obese Zucker rats (OZR).. A group of 45 OZR were uninephrectomized to accelerate renal damage, and divided into three groups: two experimental groups (IRBE and OMA) treated with 50 and 40 mg/kg/d, respectively; and the control group (CG). At the end of the 8-month follow-up period, animals were killed and the remnant kidney was removed for histologic study and to evaluate the transforming growth factor-beta1 (TGF-beta1) expression.. Both therapies reduced blood pressure (BP) versus CG (P <.001). Moreover, systolic BP was significantly lower in the OMA group than in the IRBE group (P <.001). Also, both treatments significantly lowered the urinary albumin excretion (P <.001). The OMA treatment exhibited lower values than the IRBE treatment (P <.05). The kidney TGF-beta1 expression was reduced by both treatments to a similar level. The correlation between systolic BP and glomerulosclerosis (GS) is very high (r = 0.90; P <.0001). Also, a high correlation was observed between GS and proteinuria (r = 0.79, P <.0001). The correlation between systolic BP and proteinuria was weaker (r = 0.69; P <.01).. These data suggest that both therapies are effective in ameliorating the progression of renal damage in this experimental model. Omapatrilat affords greater long-term renoprotection than irbesartan, mainly due to its potent effect in reducing systolic BP.

Topics: Albuminuria; Animals; Antihypertensive Agents; Biphenyl Compounds; Blood Pressure; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Hypertension, Renal; Irbesartan; Kidney; Nephrectomy; Pyridines; Rats; Rats, Zucker; Tetrazoles; Thiazepines; Transforming Growth Factor beta; Transforming Growth Factor beta1

Type 2 diabetes mellitus is a social and civilization-related disease that leads to various micro- and macroangiopathic complications, including diabetic nephropathy. At present, the most sensitive and non-invasive indicator of the progression of diabetic nephropathy is microalbuminuria. Morphological features such as accumulation of extracellular matrix proteins, thickening of glomerules' basement membranes are prior to microalbuminuria. The aim of our clinical study was to establish whether urine and serum TGF beta 1 levels may be significant in prognosing and evaluating a risk for developing diabetic nephropathy. The trial was carried out in 68 patients with type 2 diabetes mellitus and a group of 10 healthy subjects served as control. Urine and serum TGF beta 1 concentrations were evaluated, as well as basic laboratory parameters. After one-year-observation serum creatinine level and microalbuminuria value were investigated in 60 patients with type 2 diabetes mellitus. In patients with type 2 diabetes mellitus both urine and serum TGF beta 1 concentration were elevated. After one-year-observation of patients with type 2 diabetes mellitus it was established that the increase of serum creatinine concentration and that of microalbuminuria value were higher in those patients, whose initial TGF beta 1 levels exceeded normal values. A positive correlation between urine TGF beta 1 level and the progression of renal failure measured by the increase of serum creatinine level was observed. In conclusion, our findings indicate that urine TGF beta 1 level may be a good prognostic factor of the development of diabetic nephropathy in the course of diabetes mellitus.

Topics: Biomarkers; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Predictive Value of Tests; Prognosis; Risk Factors; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1

Progression of diabetic nephropathy is closely associated with morphological changes in glomeruli, such as thickening of the glomerular basement membrane, mesangial expansion, and glomerulosclerosis. To elucidate early glomerular events, we compared the mitogenic activity and extracellular matrix production in mesangial cells (MC) isolated from diabetic rats prior to the manifestation of nephropathy and those showing overt nephropathy. This study may help to clarify the mechanisms underlying diabetic nephropathy and provide clues about early therapeutic interventions for preventing or slowing this process.. Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a chronic model for human type 2 diabetes mellitus, and age-matched control (LETO) rats were used. Glomerular cell numbers, expression of immediate early genes (c-Fos and c-Myc) and proliferating cell nuclear antigen (PCNA), and low-density lipoprotein (LDL) deposition were determined in renal tissue sections from rats aged 15 to 75 weeks. Mesangial cells (MCs) from OLETF rats at two different stages of the disease, that is, young (12- to 14-week-old) OLETF rats (y-OLETF) prior to the manifestation of nephropathy and old (48- to 50-week-old) OLETF rats (o-OLETF) showing nephropathy, were isolated and cultured. After stimulation with native (n-) or oxidized (ox-) LDL or angiotensin II (Ang II), DNA synthesis and extracellular matrix (ECM) production were examined. Cellular expression of LDL/scavenger receptors was analyzed using fluorescence-labeled LDL and binding to 125I-labeled-LDL.. The number of cells per glomerular cross section was significantly higher in OLETF rats than in LETO rats between 25 and 65 weeks of age. In OLETF glomeruli, c-Fos, c-Myc, and PCNA were transiently expressed in the early phase. Glomerular LDL deposition increased with the age of OLETF rats. Addition of a low dose of n-LDL (10 microg/mL) to the culture medium significantly stimulated DNA synthesis of y-OLETF MCs, as compared with o-OLETF MCs and LETO MCs (P < 0.05). A high dose of n-LDL (100 microg/mL) caused cytotoxic effects in all cells. Exposure to ox-LDL minimally affected DNA synthesis of OLETF or LETO MCs. LDL receptors and scavenger receptors were predominant in y-OLETF and o-OLETF, respectively. After stimulation with n-LDL and ox-LDL, expression of type I and type III collagen, along with transforming growth factor-beta (TGF-beta), was higher in o-OLETF MCs that in y-OLETF MCs or LETO MCs. Exposure to Ang II markedly induced DNA synthesis and ECM mRNA expression in y-OLETF MCs and o-OLETF MCs, respectively.. These findings indicate that the cell proliferation process precedes the evolution of diabetic glomerulopathy. The responses of OLETF MCs to n-LDL/ox-LDL and Ang II differed depending on the stage of diabetes. In the early phase, MCs were prone to proliferate, whereas in the late stage, MCs, which expressed higher levels of TGF-beta, tended to synthesize ECM. A functional switch in MCs may contribute to the development of glomerulosclerosis in diabetic nephropathy.

Topics: Angiotensin II; Animals; Cell Count; Cell Division; Cells, Cultured; Cholesterol, LDL; Collagen Type I; Diabetes Mellitus, Type 2; Diabetic Nephropathies; DNA; Extracellular Matrix; Gene Expression; Glomerular Mesangium; Iodine Radioisotopes; Lipoproteins, LDL; Male; Matrix Metalloproteinase 2; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-myc; Rats; Rats, Inbred OLETF; Receptors, LDL; RNA, Messenger; Transforming Growth Factor beta; Vasoconstrictor Agents

Myostatin is a TGF-beta family member that acts as a negative regulator of muscle growth. Mice lacking the myostatin gene (Mstn) have a widespread increase in skeletal muscle mass resulting from a combination of muscle fiber hypertrophy and hyperplasia. Here we show that Mstn-null mice have a significant reduction in fat accumulation with increasing age compared with wild-type littermates, even in the setting of normal food intake (relative to body weight), normal body temperature, and a slightly decreased resting metabolic rate. To investigate whether myostatin might be an effective target for suppressing the development of obesity in settings of abnormal fat accumulation, we analyzed the effect of the Mstn mutation in two genetic models of obesity, agouti lethal yellow (A(y)) and obese (Lep(ob/ob)). In each case, loss of Mstn led to a partial suppression of fat accumulation and of abnormal glucose metabolism. Our findings raise the possibility that pharmacological agents that block myostatin function may be useful not only for enhancing muscle growth, but also for slowing or preventing the development of obesity and type 2 diabetes.

Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Eating; Female; Glucose; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Myostatin; Obesity; Organ Size; Transforming Growth Factor beta

Diabetes mellitus (DM) is a well-established risk factor of cardiovascular diseases. We investigated the mechanism of the progression of arteriosclerosis in DM, focusing on the role of oxidative stress and insulin resistance in vivo. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an experimental model of type 2 DM, were assigned to 3 groups, based on supplementation with vitamin E (VE) or troglitazone (TR), a VE-derived agent which improves insulin-resistance. At 36 weeks, plasma and aortic tissue 8-iso-PGF2alpha contents, a vascular proliferating eicosanoid produced in vivo by oxidative stress, were measured by EIA. TGF-beta1 and TGF-beta1 receptor II were immunohistochemically analyzed. Histopathologically, medial area and the nuclear number of smooth muscle cells of the aorta were measured. The tissue 8-iso-PGF2alpha content (pg/g tissue) was significantly decreased by either VE or TR in the aorta (untreated-OLETF, 15,332+/-3,254 vs. TR-treated-OLETF, 7,092+/-1,992 or VE-treated-OLETF, 5,394+/-836, both p<0.01), but that in plasma decreased by only VE. VE and TR improved the increased the level of the actual medial area and the number of smooth muscle cells. The expression of TGF-beta1 was reduced, but TGF-beta1 receptor II was not. 8-iso-PGF2alpha may play an important role in the progression of arteriosclerosis. Antioxidant treatment may promise significant clinical benefits in the early diabetic stage.

Topics: Animals; Aorta; Arteriosclerosis; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dinoprost; Disease Progression; Eicosanoids; F2-Isoprostanes; Lipids; Male; Oxidative Stress; Rats; Rats, Inbred OLETF; Rats, Long-Evans; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Transforming Growth Factor beta1

To determine whether urinary type IV collagen can serve as an indicator specific for diabetic nephropathy.. Using a novel sandwich ABC-ELISA to measure type IV collagen directly, the 24-hour urinary type IV collagen excretion rate was determined in 120 diabetic patients and some groups of controls. Urinary albumin determinations were made with a RIA kit at the same time. A total of 13 diabetic patients with microalbuminuria underwent percutaneous renal biopsy for definitive diagnosis of diabetic nephropathy. Type IV collagen and TGF-beta 1 immunoreactivities were detected with ABC methods in renal biopsies.. Urinary type IV collagen excretion was significantly increased in diabetic patients with microalbuminuria, especially those with albumin excretion above 200 mg/24 h. By comparison, collagen excretion was equivalent to that in healthy controls when measured in diabetics with normalbuminuria and in patients with primary glomerular disease, primary hypertension, or coronary heart disease. Urinary type IV collagen excretion in diabetics was negatively correlated with creatinine clearance. In renal biopsies from subjects with elevated collagen excretion, the glomeruli showed pathological changes typical of diabetic nephropathy. Also, excessive type IV collagen and TGF-beta 1 immunoreactivity were detected in the glomeruli, Bowman's capsule and interstitium.. Excretion of type IV collagen, possibly reflecting increased production or decreased degradation of this protein, may be a clinically useful indicator of incipient diabetic nephropathy.

Topics: Albuminuria; Biomarkers; Collagen Type IV; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Transforming Growth Factor beta

We investigated whether endothelium-derived relaxing (EDRF) and hyperpolarizing factor (EDHF) is impaired in type 2 diabetic rats (Otsuka Long-Evans Tokushima Fatty (OLETF) rat) and whether the exercise training improves impaired EDRF and EDHF. Diabetic rats were divided into the sedentary and exercise-trained groups at the age of 16 weeks. Long-Evans Tokushima Otsuka (LETO) rats were used as age-matched non-diabetic controls. EDRF as well as EDHF induced by acetylcholine in the presence of indomethacine and L-nitro N-arginine was significantly attenuated in the diabetic rats, and was further impaired with age. Exercise training significantly improved it. Both insulin resistance and abdominal fat accumulation were significantly greater in the diabetic rats, compared with the non-diabetic rats, but were decreased in exercise-trained rats. Urinary NO(2) secretion was decrease in the diabetic rats at each age, and it was improved by exercise training. The results of the study indicated that exercise training prevented impairment of EDHF, as well as EDRF in type 2 diabetic rats, presumably due to improvement of hyperglycemia and insulin resistance and increase in the production of nitric oxide by exercise training.

Topics: Acetylcholine; Age Factors; Animals; Aorta, Abdominal; Aorta, Thoracic; Biological Factors; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Endothelium, Vascular; Exercise Therapy; Histamine; Lipids; Male; Muscle Relaxation; Nitric Oxide; Rats; Rats, Inbred OLETF; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Treatment Outcome; Vasodilator Agents

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

Type 2 diabetes mellitus results from an inadequate adaptation of the functional pancreatic beta cell mass in the face of insulin resistance. Changes in the concentration of glucose play an essential role in the regulation of beta cell turnover. In human islets, elevated glucose concentrations impair beta cell proliferation and induce beta cell apoptosis via up-regulation of the Fas receptor. Recently, it has been shown that the caspase-8 inhibitor FLIP may divert Fas-mediated death signals into those for cell proliferation in lymphatic cells. We observed expression of FLIP in human pancreatic beta cells of nondiabetic individuals, which was decreased in tissue sections of type 2 diabetic patients. In vitro exposure of islets from nondiabetic organ donors to high glucose levels decreased FLIP expression and increased the percentage of apoptotic terminal deoxynucleotidyltransferase-mediated UTP end labeling (TUNEL)-positive beta cells; FLIP was no longer detectable in such TUNEL-positive beta cells. Up-regulation of FLIP, by incubation with transforming growth factor beta or by transfection with an expression vector coding for FLIP, protected beta cells from glucose-induced apoptosis, restored beta cell proliferation, and improved beta cell function. The beneficial effects of FLIP overexpression were blocked by an antagonistic anti-Fas antibody, indicating their dependence on Fas receptor activation. The present data provide evidence for expression of FLIP in the human beta cell and suggest a novel approach to prevent and treat diabetes by switching Fas signaling from apoptosis to proliferation.

Topics: Aged; Aged, 80 and over; Carrier Proteins; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspase Inhibitors; Cell Division; Cells, Cultured; Diabetes Mellitus, Type 2; fas Receptor; Glucose; Humans; Intracellular Signaling Peptides and Proteins; Islets of Langerhans; Liposomes; Middle Aged; Recombinant Proteins; Signal Transduction; Transfection; Transforming Growth Factor beta

Activation of the renal transforming growth factor-beta (TGF-beta) system likely mediates the excess production of extracellular matrix in the diabetic kidney. To establish the role of the TGF-beta system in type 2 diabetic nephropathy, we examined the intrarenal localization and expression of the TGF-beta1 isoform, the TGF-beta type II receptor, and the Smad signaling pathway in the 16-week-old db/db mouse, a genetic model of type 2 diabetes that exhibits mesangial matrix expansion, glomerular basement membrane thickening, and renal insufficiency that closely resemble the human disease. Compared with its nondiabetic db/m littermate, the db/db mouse showed significantly increased TGF-beta1 mRNA expression by in situ hybridization in both glomerular and tubular compartments. Likewise, TGF-beta1 protein, by immunohistochemical staining, was increased in both renal compartments, but the fractional expression of TGF-beta1 protein was less than that of the mRNA in the glomerulus. In situ hybridization and immunohistochemical staining for the TGF-beta type II receptor revealed concordant and significant increases of both mRNA and protein in the glomerular and tubular compartments of diabetic animals. Finally, immunohistochemistry showed preferential accumulation of Smad3 in the nuclei of glomerular and tubular cells in diabetes. The complementary technique of Southwestern histochemistry using a labeled Smad-binding element demonstrated increased binding of nuclear proteins to Smad-binding element, indicating active signaling downstream of the TGF-beta stimulus. We therefore propose that the TGF-beta system is up-regulated at the ligand, receptor, and signaling levels throughout the renal cortex in this animal model of type 2 diabetes. Our findings suggest that the profibrotic effects of TGF-beta may underlie the progression to glomerulosclerosis and tubulointerstitial fibrosis that characterize diabetic nephropathy.

Topics: Animals; Binding Sites; Cell Nucleus; Diabetes Mellitus, Type 2; DNA-Binding Proteins; Gene Expression; Glomerular Mesangium; Immunohistochemistry; In Situ Hybridization; Kidney Tubules; Mice; Mice, Inbred C57BL; Microscopy, Electron; Nuclear Proteins; Protein Binding; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; RNA, Messenger; Signal Transduction; Smad3 Protein; Trans-Activators; Transforming Growth Factor beta; Transforming Growth Factor beta1

Topics: Animals; Antibodies, Monoclonal; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fibrosis; Humans; Kidney; Mice; Signal Transduction; Transforming Growth Factor beta

Activation of protein kinase C (PKC) is implicated as an important mechanism by which diabetes causes vascular complications. We have recently shown that a PKC beta inhibitor ameliorates not only early diabetes-induced glomerular dysfunction such as glomerular hyperfiltration and albuminuria, but also overexpression of glomerular mRNA for transforming growth factor beta1 (TGF-beta1) and extracellular matrix (ECM) proteins in streptozotocin-induced diabetic rats, a model for type 1 diabetes. In this study, we examined the long-term effects of a PKC beta inhibitor on glomerular histology as well as on biochemical and functional abnormalities in glomeruli of db/db mice, a model for type 2 diabetes. Administration of a PKC beta inhibitor reduced urinary albumin excretion rates and inhibited glomerular PKC activation in diabetic db/db mice. Administration of a PKC beta inhibitor also prevented the mesangial expansion observed in diabetic db/db mice, possibly through attenuation of glomerular expression of TGF-beta and ECM proteins such as fibronectin and type IV collagen. These findings provide the first in vivo evidence that the long-term inhibition of PKC activation in the renal glomeruli can ameliorate glomerular pathologies in diabetic state, and thus suggest that a PKC beta inhibitor might be an useful therapeutic strategy for the treatment of diabetic nephropathy.

Topics: Albuminuria; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme Inhibitors; Gene Expression Regulation; Glomerular Mesangium; Indoles; Isoenzymes; Kidney Glomerulus; Male; Maleimides; Mice; Mice, Mutant Strains; Protein Kinase C; Protein Kinase C beta; Rats; Transforming Growth Factor beta

Recent data have suggested that certain growth factors and cytokines are involved in the development of diabetic nephropathy. The aim of this study was to investigate whether circulating transforming growth factor beta 1 (TGF-beta1) and tumor necrosis factor alpha (TNF-alpha) are associated with diabetic kidney disease. Serum levels of active and total TGF-beta1 and TNF-alpha were measured in type 2 diabetic patients with nephropathy (n = 23) or without (n = 35) and normoglycemic controls (n = 12). Serum levels of circulating active TGF-beta1 were significantly higher in patients with diabetic nephropathy (0.43 +/- 0.06 ng x mL(-1)) compared with diabetic patients without renal involvement (0.23 +/- 0.03 ng x mL(-1), P = .002) and healthy controls (0.24 +/- 0.03 ng x mL(-1), P= .001), whereas the levels of total (active + latent) TGF-beta1 were not different between the subgroups. Active TGF-beta1 concentrations were correlated with urinary albumin excretion (r = .49, P < .003) and serum creatinine (r= .55, P < .01). Sera from patients with type 2 diabetes contained significantly more TNF-alpha than sera from normoglycemic controls (3.07 +/- 0.24 v 1.65 +/- 0.20 pg x mL(-1), P = .001). However, the comparison of serum TNF-alpha concentrations between microalbuminuric and normoalbuminuric diabetic patients showed no significant difference (3.21 +/- 0.28 v 2.97 +/- 0.34 pg x mL(-1), P = .12). In conclusion, type 2 diabetic patients with diabetic nephropathy exhibit increased activation of TGF-beta1, in serum, suggesting an association between circulating TGF-beta1 activity and the development of renal disease.

Topics: Aged; Albuminuria; Body Mass Index; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Humans; Male; Middle Aged; Reference Values; Regression Analysis; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Emerging evidence suggests that transforming growth factor-beta (TGF-beta) is an important mediator of diabetic nephropathy. We showed previously that short-term treatment with a neutralizing monoclonal anti-TGF-beta antibody (alphaT) in streptozotocin-diabetic mice prevents early changes of renal hypertrophy and increased matrix mRNA. To establish that overactivity of the renal TGF-beta system mediates the functional and structural changes of the more advanced stages of nephropathy, we tested whether chronic administration of alphaT prevents renal insufficiency and glomerulosclerosis in the db/db mouse, a model of type 2 diabetes that develops overt nephropathy. Diabetic db/db mice and nondiabetic db/m littermates were treated intraperitoneally with alphaT or control IgG, 300 microgram three times per week for 8 wk. Treatment with alphaT, but not with IgG, significantly decreased the plasma TGF-beta1 concentration without decreasing the plasma glucose concentration. The IgG-treated db/db mice developed albuminuria, renal insufficiency, and glomerular mesangial matrix expansion associated with increased renal mRNAs encoding alpha1(IV) collagen and fibronectin. On the other hand, treatment with alphaT completely prevented the increase in plasma creatinine concentration, the decrease in urinary creatinine clearance, and the expansion of mesangial matrix in db/db mice. The increase in renal matrix mRNAs was substantially attenuated, but the excretion of urinary albumin factored for creatinine clearance was not significantly affected by alphaT treatment. We conclude that chronic inhibition of the biologic actions of TGF-beta with a neutralizing monoclonal antibody in db/db mice prevents the glomerulosclerosis and renal insufficiency resulting from type 2 diabetes.

Topics: Animals; Antibodies, Monoclonal; Carrier Proteins; Diabetes Mellitus, Type 2; Disease Models, Animal; Extracellular Matrix; Extracellular Matrix Proteins; Glomerular Mesangium; Mice; Mice, Mutant Strains; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Cell Surface; Receptors, Leptin; Receptors, Transforming Growth Factor beta; Renal Insufficiency; Transforming Growth Factor beta; Up-Regulation

Topics: Animals; Antibodies, Monoclonal; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Mice; Mice, Mutant Strains; Transforming Growth Factor beta

Advanced glycation end products (AGEs) participate in the pathogenesis of diabetic nephropathy. We reported earlier that OPB-9195, a synthetic thiazolidine derivative and novel inhibitor of advanced glycation, prevented progression of diabetic glomerulosclerosis by lowering serum concentrations of advanced glycation end products and reducing their deposition in the glomeruli. Here, we examined their contribution and that of growth factors, such as transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF), to the progression of diabetic nephropathy. We also investigated the expression of type IV collagen in the kidneys of Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats, a Type II (non-insulin-dependent) diabetes mellitus model, after treatment with OPB-9195.. Using northern blots and immunohistochemical techniques, we determined the renal expression of TGF-beta and type IV collagen mRNAs and proteins in OLETF rats. We also examined OPB-9195's effects on renal expression of VEGF mRNA and protein.. Concomitant increases in TGF-beta and type IV collagen expression were observed at each point in time in OLETF rats not given OPB-9195. In contrast, OPB-9195 treatment greatly suppressed the renal expression of TGF-beta, VEGF and type IV collagen mRNAs and proteins to that seen in non-diabetic rats.. Since OPB-9195, an AGE-inhibitor, prevented the progression of diabetic nephropathy by blocking type IV collagen production and suppressing overproduction of two growth factors, TGF-beta and VEGF, in diabetic rats, this compound warrants further investigation.

Topics: Animals; Blood Glucose; Collagen; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelial Growth Factors; Gene Expression; Glycation End Products, Advanced; Kidney; Kidney Glomerulus; Lymphokines; Male; Rats; Rats, Inbred OLETF; RNA, Messenger; Thiadiazoles; Thiazolidines; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Topics: Adult; Case-Control Studies; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Humans; Male; Smoking; Transforming Growth Factor beta

The primary aim of this study was to determine whether microalbuminuria is associated with endothelial dysfunction in Type 1 diabetes mellitus. The secondary aim was to determine whether any reported biochemical markers of cardiovascular risk are associated with endothelial dysfunction in this group.. Measurements were made of the vasodilatory responses of the brachial artery to post-ischaemic hyperaemia and to sublingual glyceryl trinitrate (GTN) (causing endothelium-dependent and endothelium-independent dilation, respectively) using a high-resolution ultrasound technique in 18 Type 1 diabetic patients with microalbuminuria, 18 age and sex-matched normoalbuminuric Type 1 diabetic patients and 18 non-diabetic control subjects.. There was a significant reduction in flow-mediated dilation (FMD) in microalbuminuric and normoalbuminuric diabetic patients compared with control subjects (2.4% (95% confidence interval (CI) 1.0-3.8%) and 2.3% (95% CI 0.7-3.9%) respectively vs. 6.3% (95% CI 5.1-7.5%), P<0.0001) but no difference in GTN-mediated dilation (14.7% (95% CI 10.7-18.7%) and 15.2% (95% CI 11.2-19.2%) vs. 18.7% (95% CI 16.1-21.3%), P = 0.09). There was no significant difference in FMD, however, between the microalbuminuric group and normoalbuminuric group (P=0.45). FMD was not significantly associated with urinary albumin-creatinine ratio, glycosylated haemoglobin, plasma glucose, lipid or lipoprotein concentrations in diabetic patients. There was a positive correlation between active transforming growth factor (TGF)-beta concentration, a novel biochemical marker of macrovascular disease, and FMD in diabetic patients (r=0.36, P<0.05). GTN-mediated dilation was positively associated with HDL-cholesterol concentration (r = 0.49, P = 0.002) but not with other biochemical variables (including active TGF-beta concentration). Active TGF-beta concentration was not associated with degree of microalbuminuria or other biochemical parameters.. These data suggest that endothelial dysfunction occurs in Type 1 diabetic patients regardless of urine albumin status. Endothelial dysfunction appears therefore to predate the development of microalbuminuria as a marker for the development of coronary artery disease. It is also concluded that low plasma levels of active TGF-beta are associated with an impaired endothelial response and this may provide a useful tool for identifying Type 1 diabetic patients at a greater risk of coronary artery disease.

Topics: Adult; Albuminuria; Brachial Artery; Cholesterol, HDL; Diabetes Mellitus, Type 2; Endothelium, Vascular; Female; Glycated Hemoglobin; Humans; Hyperemia; Insulin; Ischemia; Male; Nitroglycerin; Transforming Growth Factor beta; Vasodilation; Vasodilator Agents

Increases in extracellular matrix (ECM) and changes in its components have been documented in the glomeruli of diabetic nephropathy. Advanced glycation end products formed by glycoxidation have been shown to induce the synthesis of ECM components and transforming growth factor beta (TGF-beta), suggesting that advanced glycation end products may be involved in the etiology of imbalance of ECM components in diabetic glomerulosclerosis. The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an inbred strain that spontaneously develops non-insulin-dependent diabetes mellitus which progresses to diabetic glomerulosclerosis. Nepsilon-(carboxymethyl)lysine (CML) is known to be formed by glycoxidation. To clarify the involvement of glycoxidation in diabetic nephropathy, we examined the localization of CML, ECM components, and TGF-beta1 in the glomeruli of OLETF rats. The amounts of alpha3(IV) collagen, type VI collagen, and fibronectin were significantly increased in the glomeruli of OLETF rats, whereas the heparan sulfate proteoglycan levels were decreased. After 6 months of age, CML levels were significantly increased in the mesangial area of the glomeruli in these animals. The overexpression of TGF-beta1 preceded the increase in glomerular ECM components. The present study demonstrated that the accumulation of CML precedes the changes of glomerular ECM components in the glomeruli during the course of diabetic nephropathy, suggesting that glycoxidation may be one of the major causes of diabetic glomerulosclerosis.

Topics: Animals; Diabetes Mellitus, Type 2; Extracellular Matrix; Fluorescent Antibody Technique; Glycation End Products, Advanced; Immunoenzyme Techniques; Kidney Glomerulus; Lysine; Male; Microscopy, Electron; Rats; Rats, Inbred Strains; Time Factors; Transforming Growth Factor beta

The accumulation of extracellular matrix in the glomeruli of human and experimental models of diabetic nephropathy is associated with disease progression. Transforming growth factor beta 1 (TGF-beta1), which is a multifunctional peptide growth factor, plays a key role in the synthesis of extracellular matrix protein in vitro, and the expression of TGF-beta1 is elevated in human and rat diabetic nephropathy. In this study, we measured the urinary TGF-beta1 excretion in 57 patients with non-insulin-dependent diabetes mellitus and in 20 healthy volunteers to examine whether the determination of urinary TGF-beta1 excretion would facilitate the evaluation of the degree of mesangial expansion in patients with diabetic nephropathy. Both active and total TGF-beta1 levels in 24-hour urine samples collected from patients with diabetes mellitus and normal controls were measured using an enzyme-linked immunosorbent assay. We observed a higher excretion of urinary TGF-beta1 in patients with diabetes mellitus than in normal controls. In addition, the urinary TGF-beta1 excretion was elevated in patients with severe mesangial expansion. These results suggest that urinary TGF-beta1 may represent one parameter that can be used to evaluate the progression of diabetic nephropathy.

Topics: Biomarkers; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged; Transforming Growth Factor beta

Immunohistochemical and morphometrical studies were performed to elucidate the specificity of atherosclerosis in the descending branch (the segments 5 and 6) of the left coronary artery associated with acute myocardial infarction (AMI) in the anterior wall of the heart and non-insulin-dependent diabetes mellitus (NIDDM). The NIDDM without AMI group showed diffuse intimal thickening with smooth muscle cells, combined with much more intense immunostaining of tenascin than the non diabetic groups. The AMI without NIDDM group showed atheromatous thickening with decreased smooth muscle cells, a large number of macrophage and TUNEL-positive cells compared with the groups without AMI. However, the AMI with NIDDM group revealed atherosclerotic lesion with decreased smooth muscle cells, increased macrophages and TUNEL positive cells associated with the increased localization of tenascin and TGF-beta1 compared with the control. These findings suggest that the specificity of coronary atherosclerosis in diabetic patients may be the extensive atherosclerotic changes associated with increased tenascin. In AMI with NIDDM, increased TGF beta1 may induce apoptosis in the atheroma and coronary dysfunction, contributing to the development of acute myocardial infarction.

Topics: Actins; Aged; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Case-Control Studies; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; DNA Fragmentation; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Macrophages; Middle Aged; Muscle, Smooth, Vascular; Myocardial Infarction; Tenascin; Transforming Growth Factor beta

Diabetic nephropathy is a common complication in patients with either type I or type II diabetes. The pathogenesis of diabetic nephropathy is thought to involve both metabolic and vascular factors leading to chronic accumulation of glomerular mesangial matrix. In this context, both transforming growth factor-beta (TGF-beta) and endothelin may contribute to these processes. To determine if diabetic patients demonstrate increased renal production of TGF-beta and endothelin, aortic, renal vein, and urinary levels of these factors were measured in 14 type II diabetic patients and 11 nondiabetic patients who were undergoing elective cardiac catheterization. Renal blood flow was measured in all patients to calculate net mass balance across the kidney. Diabetic patients demonstrated net renal production of immunoreactive TGF-beta1 (830 +/- 429 ng/min [mean +/- SE]), whereas nondiabetic patients demonstrated net renal extraction of circulating TGF-beta1 (-3479 +/- 1010 ng/min, P < 0.001). Urinary levels of bioassayable TGF-beta were also significantly increased in diabetic patients compared with nondiabetic patients (2.435 +/- 0.385 vs. 0.569 +/- 0.190 ng/mg creatinine, respectively; P < 0.001). Renal production of immunoreactive endothelin was not significantly increased in diabetic patients. In summary, type II diabetes is associated with enhanced net renal production of TGF-beta1, whereas nondiabetic patients exhibit net renal extraction of circulating TGF-beta1. Increased renal TGF-beta production may be an important manifestation of diabetic kidney disease.

Topics: Aged; Cardiac Catheterization; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelins; Female; Humans; Kidney; Male; Middle Aged; Regional Blood Flow; Renal Circulation; Renal Veins; Transforming Growth Factor beta

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

The mechanism of peripheral immunological tolerance has not been fully established. While anergic T cells have been noted in tolerant hosts, the mechanism by which they contribute to the induction and maintenance of tolerance has not been defined. As we previously reported, an accelerated form of diabetogenic autoimmunity in nonobese diabetic mice can be blocked by passive transfer of a CD3+, CD8+, beta-chain variable region 11-positive islet-infiltrating T-cell clone (IS-2.15). In this report we examine the properties of this T-cell clone. We have established that this clone is unresponsive to mitogenic concentrations of anti-T-cell receptor or anti-CD3 monoclonal antibodies and is only weakly responsive to syngeneic islet and spleen cells. Moreover, these T cells secrete an inhibitory factor(s) that irreversibly inhibits interleukin (IL) 2/IL-4-driven proliferation of IL-2/IL-4 indicator T-cell lines. This noncytotoxic factor, which possesses an apparent size of 10-30 kDa, does not interfere with low-affinity IL-2 receptor expression. These data indicate that at least some anergic T cells can play an active role in peripheral tolerance by secreting suppressor factor(s) that regulate IL-2/IL-4-dependent proliferation.

Topics: Animals; CD8 Antigens; Diabetes Mellitus, Type 2; Immune Tolerance; Interleukin-2; Interleukin-4; Islets of Langerhans; Lymphocyte Activation; Lymphokines; Mice; Mice, Inbred NOD; Molecular Weight; Receptor Aggregation; Receptors, Antigen, T-Cell; Receptors, Interleukin-2; T-Lymphocyte Subsets; Transforming Growth Factor beta