transforming-growth-factor-beta and Diabetic-Cardiomyopathies

Cardiomyopathy (CDM) and related morbidity and mortality are increasing at an alarming rate, in large part because of the increase in the number of diabetes mellitus cases. The clinical consequence associated with CDM is heart failure (HF) and is considerably worse for patients with diabetes mellitus, as compared to nondiabetics. Diabetic cardiomyopathy (DCM) is characterized by structural and functional malfunctioning of the heart, which includes diastolic dysfunction followed by systolic dysfunction, myocyte hypertrophy, cardiac dysfunctional remodeling, and myocardial fibrosis. Indeed, many reports in the literature indicate that various signaling pathways, such as the AMP-activated protein kinase (AMPK), silent information regulator 1 (SIRT1), PI3K/Akt, and TGF-β/smad pathways, are involved in diabetes-related cardiomyopathy, which increases the risk of functional and structural abnormalities of the heart. Therefore, targeting these pathways augments the prevention as well as treatment of patients with DCM. Alternative pharmacotherapy, such as that using natural compounds, has been shown to have promising therapeutic effects. Thus, this article reviews the potential role of the quinazoline alkaloid, oxymatrine obtained from the Sophora flavescensin CDM associated with diabetes mellitus. Numerous studies have given a therapeutic glimpse of the role of oxymatrine in the multiple secondary complications related to diabetes, such as retinopathy, nephropathy, stroke, and cardiovascular complications via reductions in oxidative stress, inflammation, and metabolic dysregulation, which might be due to targeting signaling pathways, such as AMPK, SIRT1, PI3K/Akt, and TGF-β pathways. Thus, these pathways are considered central regulators of diabetes and its secondary complications, and targeting these pathways with oxymatrine might provide a therapeutic tool for the diagnosis and treatment of diabetes-associated cardiomyopathy.

Topics: Alkaloids; AMP-Activated Protein Kinases; Diabetes Mellitus; Diabetic Cardiomyopathies; Humans; Insulin Resistance; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirtuin 1; 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

Both type 1 and type 2 diabetes are associated with cardiac fibrosis that may reduce myocardial compliance, contribute to the pathogenesis of heart failure, and trigger arrhythmic events. Diabetes-associated fibrosis is mediated by activated cardiac fibroblasts, but may also involve fibrogenic actions of macrophages, cardiomyocytes and vascular cells. The molecular basis responsible for cardiac fibrosis in diabetes remains poorly understood. Hyperglycemia directly activates a fibrogenic program, leading to accumulation of advanced glycation end-products (AGEs) that crosslink extracellular matrix proteins, and transduce fibrogenic signals through reactive oxygen species generation, or through activation of Receptor for AGEs (RAGE)-mediated pathways. Pro-inflammatory cytokines and chemokines may recruit fibrogenic leukocyte subsets in the cardiac interstitium. Activation of transforming growth factor-β/Smad signaling may activate fibroblasts inducing deposition of structural extracellular matrix proteins and matricellular macromolecules. Adipokines, endothelin-1 and the renin-angiotensin-aldosterone system have also been implicated in the diabetic myocardium. This manuscript reviews our current understanding of the cellular effectors and molecular pathways that mediate fibrosis in diabetes. Based on the pathophysiologic mechanism, we propose therapeutic interventions that may attenuate the diabetes-associated fibrotic response and discuss the challenges that may hamper clinical translation.

Topics: Animals; Diabetes Mellitus; Diabetic Cardiomyopathies; Endomyocardial Fibrosis; Endothelial Cells; Extracellular Matrix Proteins; Gene Expression Regulation; Glycation End Products, Advanced; Humans; Hypoglycemic Agents; Macrophages; Myocytes, Cardiac; Receptor for Advanced Glycation End Products; Renin-Angiotensin System; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

Diabetic cardiomyopathy (DC) is one of the severe secondary complications of diabetes mellitus in humans. Vinpocetine is an alkaloid having pleiotropic pharmacological effects. The present study is designed to investigate the effect of vinpocetine in DC in rats.. Rats were fed a high-fat diet for nine weeks along with single dose of streptozotocin after the second week to induce DC. The haemodynamic evaluation was performed to assess the functional status of rats using the Biopac system. Cardiac echocardiography, biochemical, oxidative stress parameters and inflammatory cytokine level were analysed in addition to haematoxylin-eosin and Masson's trichome staining to study histological changes, cardiomyocyte diameter and fibrosis, respectively. Phosphodiesterase-1 (PDE-1), transforming growth factor-β (TGF-β) and p-Smad 2/3 expression in cardiac tissues were quantified using western blot/RT-PCR.. Vinpocetine treatment and its combination with enalapril decreased the glucose levels compared to diabetic rats. Vinpocetine improved the echocardiographic parameters and cardiac functional status of rats. Vinpocetine decreased the cardiac biochemical parameters, oxidative stress, inflammatory cytokine levels, cardiomyocyte diameter and fibrosis in rats. Interestingly, expressions of PDE-1, TGF-β and p-Smad 2/3 were ameliorated by vinpocetine alone and in combination with enalapril.. Vinpocetine is a well-known inhibitor of PDE-1 and the protective effect of vinpocetine in DC is exerted by inhibition of PDE-1 and subsequent inhibition of the expression of TGF-β/Smad 2/3.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Enalapril; Fibrosis; Humans; Phosphoric Diester Hydrolases; Rats; Signal Transduction; Transforming Growth Factor beta

The aim of this study was to identify the molecular mechanism for hyperglycaemia-induced metabolic memory in endothelial cells (ECs), and to show its critical importance to development of cardiovascular dysfunction in diabetes.. Hyperglycaemia induces increased nuclear factor-κB (NF-κB) signalling, up-regulation of miR-27a-3p, down-regulation of nuclear factor erythroid-2 related factor 2 (NRF2) expression, increased transforming growth factor-β (TGF-β) signalling, down-regulation of miR-29, and induction of endothelial-to-mesenchymal transition (EndMT), all of which are memorized by ECs and not erased when switched to a low glucose condition, thereby causing perivascular fibrosis and cardiac dysfunction. Similar metabolic memory effects are found for production of nitric oxide (NO), generation of reactive oxygen species (ROS), and the mitochondrial oxygen consumption rate in two different types of ECs. The observed metabolic memory effects in ECs are blocked by NRF2 activator tert-butylhydroquinone and a miR-27a-3p inhibitor. In vivo, the NRF2 activator and miR-27a-3p inhibitor block cardiac perivascular fibrosis and restore cardiovascular function by decreasing NF-κB signalling, down-regulating miR-27a-3p, up-regulating NRF2 expression, reducing TGF-β signalling, and inhibiting EndMT during insulin treatment of diabetes in streptozotocin-induced diabetic mice, whereas insulin alone does not improve cardiac function.. Our data indicate that disruption of hyperglycaemia-induced EC metabolic memory is required for restoring cardiac function during treatment of diabetes, and identify a novel molecular signalling pathway of NF-κB/miR-27a-3p/NRF2/ROS/TGF-β/EndMT involved in metabolic memory.

Topics: Animals; Blood Glucose; Cells, Cultured; Diabetic Cardiomyopathies; Disease Models, Animal; Endothelial Cells; Energy Metabolism; Epithelial-Mesenchymal Transition; Fibrosis; Humans; Hydroquinones; Male; Mice, Inbred BALB C; MicroRNAs; NF-E2-Related Factor 2; NF-kappa B; Reactive Oxygen Species; Signal Transduction; Transforming Growth Factor beta

Diabetic cardiomyopathy (DCM) is one of the primary complications of the cardiovascular system due to diabetes‑induced metabolic injury. The present study investigated the autophagy‑associated regulatory mechanisms of long non‑coding RNAs in cardiac pathological changes in diabetes mellitus (DM). Streptozotocin (STZ)‑induced diabetic rats were intramyocardially injected and high concentration glucose (HG)‑processed H9C2 cells were infected with growth arrest specific transcript 5 (GAS5)‑loaded AAV‑9 adenovirus. HG‑processed H9C2 cells also underwent transfection with small interfering RNA‑p27. Hematoxylin and eosin and Masson staining evaluated myocardial histological changes. Quantitative PCR detected the expression levels of GAS5, fibrosis markers (collagen I, collagen III, TGF‑β and connective tissue growth factor) and microRNA (miR)‑221‑3p. Western blotting determined the expression levels of autophagy‑associated proteins [microtubule‑associated proteins 1A/1B light chain 3B (LC3B) I, LC3B II and p62] and p27. Targetscan7.2 was used to predict binding sites between miR‑221‑3 and p27. Dual luciferase reporter assayed the effect of miR‑221‑3p on luciferase activity of GAS5 and p27. GAS5 downregulated high blood glucose concentrations in STZ‑induced diabetic rats, however its expression levels decreased in both HG‑processed H9C2 cells and the myocardium of DM model rats. GAS5 attenuated the histological abnormalities and reversed the decreased LC3B II and increased p62 expression levels of DM model rats. miR‑221‑3p mimic suppressed the activity of both GAS5‑wild‑type (WT) and p27‑WT. miR‑221‑3p expression levels were increased in both HG‑processed H9C2 and diabetic myocardium. p27 expression levels decreased following HG but were upregulated by GAS5. sip27 abolished the effect of GAS5 on DCM. GAS5 promoted cardiomyocyte autophagy in DCM to attenuate myocardial injury via the miR‑221‑3p/p27 axis.

Topics: Animals; Autophagy; Collagen Type I; Collagen Type II; Connective Tissue Growth Factor; Cyclin-Dependent Kinase Inhibitor p27; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Down-Regulation; Glucose; Male; MicroRNAs; Microtubule-Associated Proteins; Myocardium; Rats; RNA, Small Interfering; RNA, Small Nucleolar; Sequestosome-1 Protein; Streptozocin; Transforming Growth Factor beta; Up-Regulation

Diabetic cardiomyopathy is one of the cardiac complications in diabetes patients, eventually resulting in heart failure and increasing morbidity and mortality. Oxidative stress is a critical pathological feature in diabetic hearts, contributing to the development of DCM. Forskolin (FSK) was shown to reduce oxidative stress. This study was aimed at investigating the effects of FSK on diabetic hearts and the relevant molecular mechanisms.. Streptozotocin- (STZ-) induced diabetes in mice was treated with FSK through intraperitoneal injection. Cardiac functions were evaluated by echocardiography. Hematoxylin-eosin and Masson trichrome staining was employed to determine heart morphological changes and cardiac fibrosis, respectively. Cardiac fibrosis-related markers were detected by western blot. Superoxide dismutase activity, reduced/oxidized glutathione ratio, and malondialdehyde concentration in left ventricles were determined using respective commercial kits.. Abnormal cardiac diastolic dysfunction and cardiac fibrosis were observed in diabetic hearts. FSK treatment significantly improved the cardiac diastolic function and attenuated the abnormal morphological change in diabetic hearts. Moreover, FSK treatment in diabetic mice decreased the expression of fibronectin, collagen I, TGF-. Our study demonstrates that FSK protects against the development of DCM in STZ-induced diabetes in mice. Our study suggests that FSK might be a potential target for drug development in treating DCM.

Topics: Actins; Animals; Apoptosis; Colforsin; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Disease Models, Animal; Fibrosis; Gene Expression Regulation; Heart; Humans; Mice; Myocardium; Oxidative Stress; Transforming Growth Factor beta

Diabetic cardiomyopathy (DCM) is a common diabetic complication characterized by diastolic relaxation abnormalities, myocardial fibrosis and chronic heart failure. Although TGF-β/Smad3 signalling has been shown to play a critical role in chronic heart disease, the role and mechanisms of Smad3 in DCM remain unclear. We reported here the potential role of Smad3 in the development of DCM by genetically deleting the Smad3 gene from db/db mice. At the age of 32 weeks, Smad3WT-db/db mice developed moderate to severe DCM as demonstrated by a marked increase in the left ventricular (LV) mass, a significant fall in the LV ejection fraction (EF) and LV fractional shortening (FS), and progressive myocardial fibrosis and inflammation. In contrast, db/db mice lacking Smad3 (Smad3KO-db/db) were protected against the development of DCM with normal cardiac function and undetectable myocardial inflammation and fibrosis. Interestingly, db/db mice with deleting one copy of Smad3 (Smad3 ± db/db) did not show any cardioprotective effects. Mechanistically, we found that deletion of Smad3 from db/db mice largely protected cardiac Smad7 from Smurf2-mediated ubiquitin proteasome degradation, thereby inducing IBα to suppress NF-kB-driven cardiac inflammation. In addition, deletion of Smad3 also altered Smad3-dependent miRNAs by up-regulating cardiac miR-29b while suppressing miR-21 to exhibit the cardioprotective effect on Smad3KO-db/db mice. In conclusion, results from this study reveal that Smad3 is a key mediator in the pathogenesis of DCM. Targeting Smad3 may be a novel therapy for DCM.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Fibrosis; Inflammation; Mice; Mice, Inbred C57BL; Mice, Knockout; Signal Transduction; Smad3 Protein; Transforming Growth Factor beta

Topics: Animals; Anti-Inflammatory Agents; Cardiotonic Agents; Cell Line; Connexin 43; Diabetic Cardiomyopathies; Fibrosis; Glycyrrhizic Acid; Humans; Myocytes, Cardiac; NAV1.5 Voltage-Gated Sodium Channel; NF-E2-Related Factor 2; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Zucker; Receptor for Advanced Glycation End Products; Receptors, CXCR4; Transforming Growth Factor beta; Troponin I

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

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Fibrosis; Myocardium; ortho-Aminobenzoates; Random Allocation; Rats; Rats, Sprague-Dawley; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

The balance of pro-angiogenic and anti-angiogenic factors has a significant role in the development of diabetic cardiomyopathy. The purpose of this study was to examine the effect of 8 weeks of high-intensity interval training (HIIT) and moderate intensity continuous training (MICT) on the myocardial angiogenic factors and histological changes in male diabetic rats. Thirty-two male Wistar rats were randomly assigned into four groups: healthy non-exercised control, diabetic (D), D + HIIT, and D+ MICT groups. Diabetes type 2 was induced by a high-fat diet for 2 weeks and a single injection of streptozotocin. Following confirmation of diabetes, animals were subjected to HIIT (90 to 95% of VO2max) or MICT (50-65% of VO2max) protocols 5 days a week for 8 weeks. Western blotting was used for detection of protein expressions of vascular endothelial growth factor (VEGF), transforming growth factor-beta (TGF-β), matrix metalloproteinase-2 (MMP2), and tissue inhibitor of matrix metalloproteinase-2 (TIMP2) in the left ventricle. In addition, baseline and final blood glucose and body weight were measured. Histological changes were evaluated using H&E and Masson's trichrome staining. The results showed that exercise increased protein levels of pro-angiogenic factors while reduced anti-angiogenic factors protein levels in diabetic animals. These changes were followed by increased capillary density and reduced interstitial fibrosis in the left ventricle. Moreover, the MICT was superior to HIIT in enhancing angiogenic factors and attenuation of blood glucose and fibrosis in the diabetic rats. These findings confirm the effectiveness of exercise, particularly MICT, in the improvement of diabetic cardiomyopathy.

Topics: Angiogenic Proteins; Animals; Blood Glucose; Coronary Vessels; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Fibrosis; Male; Matrix Metalloproteinase 2; Neovascularization, Physiologic; Physical Conditioning, Animal; Random Allocation; Rats; Rats, Wistar; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Topics: AMP-Activated Protein Kinases; Animals; Antimicrobial Cationic Peptides; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Echocardiography; Endothelial Cells; Endothelium; Epithelial-Mesenchymal Transition; Fibrosis; Glucose; Hemodynamics; Hyperglycemia; Male; Mice; Mice, Inbred C57BL; Pyrazoles; Pyrroles; Signal Transduction; Transforming Growth Factor beta

Matrine might play a vital role in cardiovascular diseases progression and treatment.. We aimed to explore the protective effects and potential mechanism of matrine against diabetic cardiomyopathy (DCM) in rat model.. A rat model of DCM was induced by streptozotocin, which were then divided into two groups and treated with matrine. Inflammatory cytokines were investigated in serum and myocardial cells after matrine administration. The effects of matrine on cardiac reactive oxygen species (ROS) generation, Malondialdehyde (MDA) levels, and Glutathione peroxidase (GPx), PPARγ1 activity were detected in myocardial cells. The protein kinase RNA-like endoplasmic reticulum kinase (PERK) signal pathway in endoplasmic reticulum stress was studied to elaborated protective effects of matrine in DCM rat by Western blot analysis. Fasting blood glucose and hemodynamic parameters were analyzed after treatment with matrine.. Matrine-inhibited expression levels of inflammatory cytokines of tumor necrosis factor alpha (TNF-α) and interleukin 6. Matrine administration decreased ROS generation, MDA, and transforming growth factor beta levels, and Peroxisome proliferator-activated receptor beta (PPARβ) and Peroxisome proliferator-activated receptorγ 1 (PPARγ1) activity. Matrine administration also significantly inhibited PERK expression. Endogenic expression of PERK canceled matrine-induced apoptosis of myocardial cells. Notably, treatment with matrine significantly decreased nonfasting blood glucose levels and improved hemodynamic parameters of DCM rat.. Matrine may be a promising agent for the treatment of DCM.

Topics: Alkaloids; Animals; Apoptosis; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; eIF-2 Kinase; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Humans; Malondialdehyde; Matrines; Myocardium; PPAR gamma; Protein Kinases; Quinolizines; Rats; Reactive Oxygen Species; RNA; Signal Transduction; Transforming Growth Factor beta

In the diabetic heart, there is excessive dependence on fatty acid (FA) utilization to generate ATP. Lipoprotein lipase (LPL)-mediated hydrolysis of circulating triglycerides is suggested to be the predominant source of FA for cardiac utilization during diabetes. In the heart, the majority of LPL is synthesized in cardiomyocytes and secreted onto cell surface heparan sulfate proteoglycan (HSPG), where an endothelial cell (EC)-releasable β-endoglycosidase, heparanase cleaves the side chains of HSPG to liberate LPL for its onward movement across the EC. EC glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) captures this released enzyme at its basolateral side and shuttles it across to its luminal side. We tested whether the diabetes-induced increase of transforming growth factor-β (TGF-β) can influence the myocyte and EC to help transfer LPL to the vascular lumen to generate triglyceride-FA. In response to high glucose and EC heparanase secretion, this endoglycosidase is taken up by the cardiomyocyte (Wang Y, Chiu AP, Neumaier K, Wang F, Zhang D, Hussein B, Lal N, Wan A, Liu G, Vlodavsky I, Rodrigues B. Diabetes 63: 2643-2655, 2014) to stimulate matrix metalloproteinase-9 expression and the conversion of latent to active TGF-β. In the cardiomyocyte, TGF-β activation of RhoA enhances actin cytoskeleton rearrangement to promote LPL trafficking and secretion onto cell surface HSPG. In the EC, TGF-β signaling promotes mesodermal homeobox 2 translocation to the nucleus, which increases the expression of GPIHBP1, which facilitates movement of LPL to the vascular lumen. Collectively, our data suggest that in the diabetic heart, TGF-β actions on the cardiomyocyte promotes movement of LPL, whereas its action on the EC facilitates LPL shuttling. NEW & NOTEWORTHY Endothelial cells, as first responders to hyperglycemia, release heparanase, whose subsequent uptake by cardiomyocytes amplifies matrix metalloproteinase-9 expression and activation of transforming growth factor-β. Transforming growth factor-β increases lipoprotein lipase secretion from cardiomyocytes and promotes mesodermal homeobox 2 to enhance glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1-dependent transfer of lipoprotein lipase across endothelial cells, mechanisms that accelerate fatty acid utilization by the diabetic heart.

Topics: Animals; Blood Glucose; Cell Communication; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Endothelial Cells; Energy Metabolism; Fatty Acids; Glucuronidase; Homeodomain Proteins; Lipoprotein Lipase; Male; Matrix Metalloproteinase 9; Muscle Proteins; Myocytes, Cardiac; Rats, Wistar; Receptors, Lipoprotein; Signal Transduction; Transforming Growth Factor beta

Emerging evidence indicates that irisin provides beneficial effects in diabetes. However, whether irisin influences the development of diabetic cardiomyopathy (DCM) remains unclear. Therefore, we investigated the potential role and mechanism of action of irisin in diabetes-induced myocardial dysfunction in mice. Type 1 diabetes was induced in mice by injecting streptozotocin, and the diabetic mice were administered recombinant r-irisin (low or high dose: 0.5 or 1.5 μg/g body weight/day, I.P.) or PBS for 16 weeks. Irisin treatment did not alter blood glucose levels in the diabetic mice. However, the results of echocardiographical and histopathological assays indicated that low-dose irisin treatment alleviated cardiac fibrosis and left ventricular function in the diabetic mice, whereas high-dose irisin failed to mitigate the ventricular function impairment and increased collagen deposition. The potential mechanism underlying the effect of low-dose irisin involved irisin-mediated inhibition of high glucose-induced endothelial-to-mesenchymal transition (EndMT); conversely, high-dose irisin treatment enhanced high glucose-induced MMP expression by stimulating MAPK (p38 and ERK) signalling and cardiac fibroblast proliferation and migration. Low-dose irisin alleviated DCM development by inhibiting high glucose-induced EndMT. By contrast, high-dose irisin disrupted normal MMP expression and induced cardiac fibroblast proliferation and migration, which results in excess collagen deposition. Thus, irisin can inhibit high glucose-induced EndMT and exert a dose-dependent bidirectional effect on DCM.

Topics: Animals; Blood Glucose; Cell Movement; Cell Proliferation; Collagen; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Enzyme Activation; Extracellular Matrix; Extracellular Signal-Regulated MAP Kinases; Fibroblasts; Fibronectins; Fibrosis; Glucose; Human Umbilical Vein Endothelial Cells; Humans; Mesoderm; Mice, Inbred C57BL; Myocardium; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Signal Transduction; Smad Proteins; Streptozocin; Transforming Growth Factor beta

Cardiac fibrosis is one of the pathological characteristics of diabetic cardiomyopathy (DbCM). Matrine treatment has proven to be effective in cases of organ fibrosis and cardiovascular diseases. In the present study, the anti-fibrosis-associated cardioprotective effects of matrine on DbCM were investigated. Rats with experimental DbCM were administered matrine orally. Cardiac functions were evaluated using invasive hemodynamic examinations. Cardiac compliance was assessed in isolated hearts. Using Sirius Red and fluorescence staining, the collagen in diabetic hearts was visualized. MTT assay was used to select non‑cytotoxic concentrations of matrine, which were subsequently used to treat isolated cardiac fibroblasts incubated under various conditions. Western blotting was performed to assess activation of the transforming growth factor‑β1 (TGF‑β1)/Smad signaling pathway. Rats with DbCM exhibited impaired heart compliance and left ventricular (LV) functions. Excessive collagen deposition in cardiac tissue was also observed. Furthermore, TGF‑β1/R‑Smad (Smad2/3) signaling was revealed to be markedly activated; however, the expression of inhibitory Smad (I‑Smad, also termed Smad7) was reduced in DbCM. Matrine administration led to a marked recovery in LV function and heart compliance by exerting inhibitory effects on TGF‑β1/R‑Smad signaling pathway‑induced fibrosis without affecting I‑Smad. Incubation with a high concentration of glucose triggered the TGF‑β1/R‑Smad (Smad2/3) signaling pathway and suppressed I‑Smad signaling transduction in cultured cardiac fibroblasts, which led to an increase in the synthesis of collagen. After cardiac fibroblasts had been treated with matrine at non‑cytotoxic concentrations without affecting I‑Smad, matrine blocked TGF‑β1/R‑Smad signaling transduction to repress collagen production and deposition. In conclusion, the results of the present study demonstrated that TGF‑β1/Smad signaling‑associated cardiac fibrosis is involved in the impairment of heart compliance and LV dysfunction in DbCM. By exerting therapeutic effects against cardiac fibrosis via its influence on TGF‑β1/Smad signaling, matrine exhibited cardioprotective effects in DbCM.

Topics: Alkaloids; Animals; Blood Glucose; Cardiotonic Agents; Cell Proliferation; Cells, Cultured; Collagen; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Drug Evaluation, Preclinical; Female; Fibrosis; Heart Ventricles; Male; Matrines; Quinolizines; Rats, Sprague-Dawley; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

Diabetic cardiomyopathy (DCM) is a kind of disease caused by metabolic disorders and microangiopathy. The main pathophysiological changes of DCM include fibrosis, myocardial cell apoptosis and autonomic neuropathy. Therefore, treatment aimed at these processes may benefit patients with DCM. We designed an experiment with the peroxisome proliferator-activated receptor-gamma (PPARγ) agonist GW 1929 to detect whether the activation of PPARγ could alleviate the degree of DCM. To further detect the mechanism of PPARγ in DCM, we used the PPARγ antagonist GW 9662 and ERK antagonist PD 098059 both in vitro and in vivo and found that PPARγ functioned by inhibiting ERK. We also performed Western blot, PCR, ELISA, immunohistochemistry, TUNEL assay, Sirius red staining and gelatin zymography to investigate inflammation, apoptosis, MMP activity and epithelial-to-mesenchymal transition (EMT). The results showed that the activation of PPARγ inhibited these reactions and inhibiting ERK also simulated this phenomenon. In conclusion, these results demonstrated that PPARγ activation in the diabetic myocardium of mice reduces myocardial fibrosis via regulation of the TGF-β/ERK pathway and EMT.

Topics: Animals; Benzophenones; Diabetic Cardiomyopathies; Epithelial-Mesenchymal Transition; Fibrosis; Inflammation; Male; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Myocardium; Peroxisome Proliferator-Activated Receptors; PPAR gamma; Signal Transduction; Transforming Growth Factor beta; Tyrosine

Myocardial fibrosis is an essential hallmark of diabetic cardiomyopathy (DCM) contributing to cardiac dysfunctions. Resveratrol, an antioxidant, exerts its anti-fibrotic effect via inhibition of oxidative stress, while the underlying molecular mechanism remains largely elusive. Periostin, a fibrogenesis matricellular protein, has been shown to be associated with oxidative stress. In the present study, we investigated the role of periostin in anti-fibrotic effect of resveratrol in streptozocin (STZ)-induced diabetic heart and the underlying mechanisms.. Diabetic mice were induced by STZ injection. After treatment with resveratrol (5 or 25 mg/kg/day i.g) or Saline containing 0.5% carboxymethyl cellulose (CMC) for 2 months, the hearts were detected for oxidative stress and cardiac fibrosis using western blot, Masson's trichrome staining and Dihydroethidium (DHE) staining. In in vitro experiments, proliferation and differentiation of fibroblasts under different conditions were investigated through western blot, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay and immunofluorescence staining.. Administration of resveratrol significantly mitigated oxidative level, interstitial fibrosis and expressions of related proteins in STZ-induced diabetic hearts. In in vitro experiments, resveratrol exhibited anti-proliferative effect on primary mouse cardiac fibroblasts via inhibiting reactive oxygen species (ROS)/extracellular regulated kinase (ERK) pathway and ameliorated myofibroblast differentiation via suppressing ROS/ERK/ transforming growth factor β (TGF-β)/periostin pathway.. Increased ROS production, activation of ERK/TGF-β/periostin pathway and myocardial fibrosis are important events in DCM. Alleviated ROS genesis by resveratrol prevents myocardial fibrosis by regulating periostin related signaling pathway. Thus, inhibition of ROS/periostin may represent a novel approach for resveratrol to reverse fibrosis in DCM.

Topics: Animals; Antioxidants; Cell Adhesion Molecules; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Fibrosis; Heart; Male; MAP Kinase Signaling System; Mice; Myocardium; Oxidative Stress; Reactive Oxygen Species; Resveratrol; Signal Transduction; Stilbenes; Transforming Growth Factor beta

Diabetic cardiomyopathy (DCM) is an established complication of diabetes mellitus. In West Virginia, the especially high incidence of diabetes and heart failure validate the necessity of developing new strategies for earlier detection of DCM. Since most DCM patients remain asymptomatic until the later stages of the disease when the fibrotic complications become irreversible, we aimed to explore biomarkers that can identify early-stage DCM.. The patients were grouped into 4 categories based on clinical diabetic and cardiac parameters: Control, Diabetes (DM), Diastolic dysfunction (DD), and Diabetes with diastolic dysfunction (DM+DD), the last group being the preclinical DCM group.. Echocardiography images indicated severe diastolic dysfunction in patients with DD+DM and DD compared to DM or control patients. In the DM and DM+DD groups, TNFα, isoprostane, and leptin were elevated compared to control (p<0.05), as were clinical markers HDL, glucose and hemoglobin A1C. Fibrotic markers IGFBP7 and TGF-β followed the same trend. The Control group showed higher beneficial levels of adiponectin and bilirubin, which were reduced in the DM and DM+DD groups (p<0.05).. The results from our study support the clinical application of biomarkers in diagnosing early stage DCM, which will enable attenuation of disease progression prior to the onset of irreversible complications.

Topics: Adiponectin; Bilirubin; Biomarkers; Case-Control Studies; Diabetic Cardiomyopathies; Electrocardiography; Humans; Insulin-Like Growth Factor Binding Proteins; Interleukin-6; Isoprostanes; Leptin; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; West Virginia

Heart failure in diabetics is associated with cardiac hypertrophy, fibrosis and diastolic dysfunction. Activation of transforming growth factor-β/Smad3 signaling in the diabetic myocardium may mediate fibrosis and diastolic heart failure, while preserving matrix homeostasis. We hypothesized that Smad3 may play a key role in the pathogenesis of cardiovascular remodeling associated with diabetes mellitus and obesity.. We generated leptin-resistant db/db Smad3 null mice and db/db Smad3+/- animals. Smad3 haploinsufficiency did not affect metabolic function in db/db mice, but protected from myocardial diastolic dysfunction, while causing left ventricular chamber dilation. Improved cardiac compliance and chamber dilation in db/db Smad3+/- animals were associated with decreased cardiomyocyte hypertrophy, reduced collagen deposition, and accentuated matrix metalloproteinase activity. Attenuation of hypertrophy and fibrosis in db/db Smad3+/- hearts was associated with reduced myocardial oxidative and nitrosative stress. db/db Smad3 null mice had reduced weight gain and decreased adiposity associated with attenuated insulin resistance, but also exhibited high early mortality, in part, because of spontaneous rupture of the ascending aorta. Ultrasound studies showed that both lean and obese Smad3 null animals had significant aortic dilation. Aortic dilation in db/db Smad3 null mice occurred despite reduced hypertension and was associated with perturbed matrix balance in the vascular wall.. Smad3 mediates diabetic cardiac hypertrophy, fibrosis, and diastolic dysfunction, while preserving normal cardiac geometry and maintaining the integrity of the vascular wall.

Topics: Animals; Aorta; Aortic Aneurysm; Aortic Rupture; Cardiomegaly; Diabetic Cardiomyopathies; Dilatation, Pathologic; Disease Models, Animal; Female; Fibrosis; Male; Matrix Metalloproteinases; Mice, Inbred C57BL; Mice, Knockout; Myocardium; Obesity; Signal Transduction; Smad3 Protein; Time Factors; Transforming Growth Factor beta; Vascular Remodeling; Ventricular Dysfunction, Left; Ventricular Remodeling

This study aimed to investigate the effect of Nox2 on cardiac fibrosis and to elucidate the regulatory mechanism of Nox2 in the development of DCM.. We established normal and insulin-resistant cellular model using neonatal rat cardiac fibroblasts. Then Nox2-specific siRNA were transfected into cardiac fibroblasts with Lipofectamine ® 2000 and crambled siRNA sequence was considered as control. Meanwhile, a part of cells were randomly selected to be treated with or without transforming growth factor-β (TGF-β). Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were respectively performed to determine the expression level of related molecules, such as Nox2, collagen type I and III (COL I and III) and PI3K/AKT and PKC/Rho signaling pathway-related proteins.. TGF-β stimulation significantly increased the expression level of Nox2 both in mRNA and protein levels. Suppression of the Nox2 markedly decreased the expression of COL I and COL III in normal and insulin-resistant cellular model with TGF-β stimulation. Moreover, suppression of the Nox2 significantly decreased the expression of PI3K/AKT and PKC/Rho signaling pathway-related proteins in insulin-resistant cellular model with TGF-β stimulation. However, suppression of Nox2 had no effects on these proteins without TGF-β stimulation.. Our finding reveals that Nox2 may promote synthesis of COL I and III via involved in PI3K/AKT and PKC/Rho signaling pathway in a TGF-β dependent manner and consequently promote cardiac fibrosis in the development of DCM.

Topics: Animals; Blotting, Western; Collagen; Diabetic Cardiomyopathies; Disease Models, Animal; Fibroblasts; Fibrosis; Membrane Glycoproteins; NADPH Oxidase 2; NADPH Oxidases; Rats; Real-Time Polymerase Chain Reaction; RNA, Small Interfering; Signal Transduction; Transfection; Transforming Growth Factor beta

Long-standing diabetes is associated with increased oxidative stress and cardiac fibrosis. This, in turn, contributes to the progression of cardiomyopathy. The present study was sought to investigate whether the free radical scavenger, 4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl (tempol) can protect against diabetic cardiomyopathy and to explore the specific underlying mechanism(s) in this setting. Diabetes was induced in rats by a single intraperitoneal injection dose of streptozotocin (50 mg/kg). These animals were treated with tempol (18 mg kg(-1) day(-1), orally) for 8 weeks. Our results showed significant increases in collagen IV and fibronectin protein levels and a marked decrease in matrix metalloproteinase-2 (MMP-2) activity measured by gelatin-gel zymography alongside elevated cardiac transforming growth factor (TGF)-β level determined using ELISA or immunohistochemistry in cardiac tissues of diabetic rats compared with control. This was accompanied by an increased in the oxidative stress as evidenced by increased reactive oxygen species (ROS) production and decreased antioxidant enzyme capacity along with elevated lactate dehydrogenase (LDH) and creatine kinase (CK-MB) serum levels as compared with the control. Tempol treatment significantly corrected the changes in the cardiac extracellular matrix, TGF-β, ROS or serum LDH, CK-MB levels, and normalized MMP-2 activity along with preservation of cardiac tissues integrity of diabetic rats against damaging responses. Moreover, tempol normalized the elevated systolic blood pressure and improved some cardiac functions in diabetic rats. Collectively, our data suggest a potential protective role of tempol against diabetes-associated cardiac fibrosis in rats via reducing oxidative stress and extracellular matrix remodeling.

Topics: Animals; Antioxidants; Collagen Type IV; Creatine Kinase, MB Form; Cyclic N-Oxides; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Fibronectins; Fibrosis; L-Lactate Dehydrogenase; Male; Matrix Metalloproteinase 2; Myocardium; Oxidative Stress; Rats; Rats, Sprague-Dawley; Spin Labels; Transforming Growth Factor beta

Alpha-lipoic acid (ALA), a naturally occurring compound, exerts powerful protective effects in various cardiovascular disease models. However, its role in protecting against diabetic cardiomyopathy (DCM) has not been elucidated. In this study, we have investigated the effects of ALA on cardiac dysfunction, mitochondrial oxidative stress (MOS), extracellular matrix (ECM) remodeling and interrelated signaling pathways in a diabetic rat model.. Diabetes was induced in rats by I.V. injection of streptozotocin (STZ) at 45 mg/kg. The animals were randomly divided into 4 groups: normal groups with or without ALA treatment, and diabetes groups with or without ALA treatment. All studies were carried out 11 weeks after induction of diabetes. Cardiac catheterization was performed to evaluate cardiac function. Mitochondrial oxidative biochemical parameters were measured by spectophotometeric assays. Extracellular matrix content (total collagen, type I and III collagen) was assessed by staining with Sirius Red. Gelatinolytic activity of Pro- and active matrix metalloproteinase-2 (MMP-2) levels were analyzed by a zymogram. Cardiac fibroblasts differentiation to myofibroblasts was evaluated by Western blot measuring smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β). Key components of underlying signaling pathways including the phosphorylation of c-Jun N-terminal kinase (JNK), p38 MAPK and ERK were also assayed by Western blot.. DCM was successfully induced by the injection of STZ as evidenced by abnormal heart mass and cardiac function, as well as the imbalance of ECM homeostasis. After administration of ALA, left ventricular dysfunction greatly improved; interstitial fibrosis also notably ameliorated indicated by decreased collagen deposition, ECM synthesis as well as enhanced ECM degradation. To further assess the underlying mechanism of improved DCM by ALA, redox status and cardiac remodeling associated signaling pathway components were evaluated. It was shown that redox homeostasis was disturbed and MAPK signaling pathway components activated in STZ-induced DCM animals. While ALA treatment favorably shifted redox homeostasis and suppressed JNK and p38 MAPK activation.. These results, coupled with the excellent safety and tolerability profile of ALA in humans, demonstrate that ALA may have therapeutic potential in the treatment of DCM by attenuating MOS, ECM remodeling and JNK, p38 MAPK activation.

Topics: Actins; Animals; Blotting, Western; Cardiac Catheterization; Cardiotonic Agents; Cell Differentiation; Collagen Type I; Collagen Type II; Diabetes Mellitus, Experimental; Diabetic Cardiomyopathies; Enzyme Activation; Enzyme Precursors; Extracellular Matrix; Fibrosis; Gelatinases; Male; Matrix Metalloproteinase 2; Mitochondria, Heart; Mitogen-Activated Protein Kinases; Myocardium; Myofibroblasts; Oxidative Stress; Phosphorylation; Rats; Rats, Wistar; Signal Transduction; Spectrophotometry; Thioctic Acid; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta; Ventricular Function, Left; Ventricular Remodeling

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