transforming-growth-factor-beta and Diabetic-Angiopathies

Diabetes mellitus is characterized by a lack of insulin causing elevated blood glucose, often with associated insulin resistance. Over time, especially in genetically susceptible individuals, such chronic hyperglycemia can cause tissue injury. One pathological response to tissue injury is the development of fibrosis, which involves predominant extracellular matrix (ECM) accumulation. The main factors that regulate ECM in diabetes are thought to be pro-sclerotic cytokines and protease/anti-protease systems. This review will examine the key markers and regulators of tissue fibrosis in diabetes and whether their levels in biological fluids may have clinical utility.

Topics: Animals; Basement Membrane; Biomarkers; Cardiomyopathies; Connective Tissue Growth Factor; Diabetes Complications; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Endothelium, Vascular; Extracellular Matrix; Fatty Liver; Fibrosis; Glycation End Products, Advanced; Heart Diseases; Heart Failure; Humans; Hyperglycemia; Immediate-Early Proteins; Insulin Resistance; Intercellular Signaling Peptides and Proteins; Liver Cirrhosis; Metalloproteases; Peptide Fragments; Procollagen; Renin-Angiotensin System; Transforming Growth Factor beta; Tunica Intima; Up-Regulation

Topics: Animals; Clinical Trials as Topic; Diabetic Angiopathies; Disease Models, Animal; Humans; Indoles; Maleimides; Protein Kinase C; Protein Kinase C beta; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Topics: Animals; Diabetic Angiopathies; Humans; Muscle, Smooth, Vascular; Neovascularization, Pathologic; Risk Factors; Transforming Growth Factor beta

Diabetic retinopathy (DR) and diabetic nephropathy (DN) are the most common microvascular complications of diabetes. DR is a leading cause of blindness, and DN is a major cause of end-stage renal diseases. Diabetic macular edema (DME) resulting from increased vascular permeability in the retina and retinal neovascularization (NV) represent two major pathological changes in DR and are the primary causes of vision loss in diabetic patients. Previous studies have shown that angiogenic factors such as vascular endothelial growth factor (VEGF) play a key role in the development of DME and retinal NV. Studies in recent years have demonstrated that a number of endogenous angiogenic inhibitors are present in the normal retina and counter act the effect of VEGF in the regulation of angiogenesis and vascular permeability. Decreased levels of angiogenic inhibitors in the vitreous and retina have been found in diabetic patients and diabetic animal models. The decreased levels of angiogenic inhibitors shift the balance between angiogenic factors and angiogenic inhibitors and consequently, lead to the development of DME and retinal NV. Recently, we have found that these angiogenic inhibitors are expressed at high levels in the normal kidney and are down-regulated in diabetes. Moreover, these inhibitors inhibit the activity of VEGF and TGF-beta, two major pathogenic factors of DN. Therefore, decreased levels of these angiogenic inhibitors in diabetes may be associated with pathologies of DN. This review will summarize recent progress in these fields and therapeutic approaches to use angiogenic inhibitors for the treatment of diabetic complications.

Topics: Angiogenesis Inhibitors; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Down-Regulation; Growth Substances; Humans; Incidence; Models, Biological; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Diabetes in its early stages is associated with enhanced glomerular blood flow and systemic vasodilation. Possible consequences of enhanced glomerular blood flow are glomerular hypertrophy, increased shear stress, and subsequent glomerulosclerosis. The prosclerotic cytokine, transforming growth factor-beta (TGF-beta), has been well established to play a key role in mesangial matrix accumulation in diabetes; however, its role in regulating vascular tone has not been studied in depth. Earlier studies have demonstrated that vascular smooth muscle cells and mesangial cells pretreated with TGF-beta have impaired calcium mobilization to inositol 1,4,5-trisphosphate (IP3) generating agonists, such as platelet-derived growth factor (PDGF) and Angiotensin I1 (Ang II). We postulated that this action of TGF-beta may be caused by regulation of the key intracellular calcium channel, the inositol 1,4,5-trisphosphate receptor (IP3R). Mesangial and smooth muscle cells primarily contain the types I IP3R and III IP3R isoforms. Short-term exposure of mesangial cells to TGF-beta (15-60 min) leads to phosphorylation of the type I IP3R at specific serine residues. Long-term exposure of mesangial cells to TGF-beta (24 hours) leads to down-regulation of protein levels of both types I and III IP3Rs as assessed by Western blot and confocal analysis. Permeabilization of cells and exposure to IP3 leads to impaired calcium mobilization if cells are pretreated with TGF-beta. As an in vivo correlation, we found that streptozotocin-induced diabetic rats and mice have reduced renal type I IP3R expression. By immunostaining, we found reduction of type I IP3R in glomerular cells and arteriolar smooth muscle cells of the diabetic rat kidney. Treatment of diabetic mice with a neutralizing anti-TGF-beta antibody completely prevents diabetic glomerular hypertrophy. We conclude that the vascular dysfunction of diabetes leading to glomerular hypertrophy is mediated, in part, by TGF-beta-induced regulation of IP3Rs.

Topics: Animals; Calcium; Calcium Channels; Diabetic Angiopathies; Humans; Hypertrophy; Inositol 1,4,5-Trisphosphate Receptors; Kidney Glomerulus; Mice; Protein Isoforms; Rats; Receptors, Cytoplasmic and Nuclear; Transforming Growth Factor beta

Patients with insulin-dependent diabetes mellitus (IDDM) and albuminuria are at high risk for severe micro- and macrovascular complications. Diabetic vascular complications are characterized by structural alterations of extracellular matrix (ECM) components in glomeruli and large vessel walls, namely, accumulation of collagen IV, collagen VI and fibronectin and relative decrease of heparan sulphate proteoglycan (HSPG). We hypothesize that the defect remodelling of ECM contributing to nephropathy and macrovascular disease is induced by overproduction of transforming growth factor-beta (TGF-beta). Recent reports indicate that hyperglycaemia, increased intraglomerular pressure, and glycated proteins potentially induce overproduction of TGF-beta in diabetes. TGF-beta stimulates production of ECM components such as collagen IV, fibronectin, proteoglycans (decorin and biglycan) without increasing HSPG. TGF-beta overproduction leads to glomerulosclerosis and TGF-beta is a causal factor in myointimal hyperplasia after balloon injury of carotid artery. It mediates angiotensin II modulator effect on smooth muscle cell growth. These findings may indicate TGF-beta overproduction to be a common pathogenetic step explaining the well-known association between micro- and macrovascular complications in diabetic patients. TGF-beta antagonists, such as decorin, betaglycan, and possibly also heparin, might be potential candidates for future therapy to prevent diabetic vascular disease.

Topics: Animals; Cytokines; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Diabetic Nephropathies; Extracellular Matrix; Humans; Risk Factors; Transforming Growth Factor beta

Diabetes mellitus is associated with typical patterns of long term vascular complications which vary with the organ involved. The microvascular kidney disease (Olgemoller and Schleicher, 1993) is characterized by thickening of the capillary basement membranes and increased deposition of extracellular matrix components (ECM), while loss of microvessels with subsequent neovascularisation is predominant in the eye and peripheral nerves. On the other hand macrovascular disease is characterized by accelerated atherosclerosis. These complications are dependent on long term hyperglycemia. Specific biochemical pathways linking hyperglycaemia to microvascular changes were proposed: the polyol pathway (Greene et al., 1987), non-enzymatic glycation of proteins (Brownlee et al., 1988), glucose autooxidation and oxidative stress (Hunt et al., 1990), hyperglycemic pseudohypoxia (Williamson et al., 1993) enhanced activation of protein kinase C by de novo-synthesis of diacyl glycerol (Lee et al., 1989; DeRubertis and Craven 1994) and others. These pathways are not mutually exclusive (Larkins and Dunlop, 1992; Pfeiffer and Schatz, 1992). They may be linked to alterations in the synthesis of growth factors particularly since atherosclerosis and angioneogenesis are associated with increased proliferation of endothelial and smooth muscle cells. Increased synthesis of ECM components is stimulated by growth factors like transforming growth factor beta (TGF beta) (Derynck et al., 1984) and insulin-like growth factor I (IGF-I) (Moran et al., 1991). This review will summarize some of the recent evidence for an involvement of growth factors in diabetic vascular complications and will attempt to assign their emergence in the sequence of events leading to vascular complications.

Topics: Animals; Arteriosclerosis; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Epidermal Growth Factor; Fibroblast Growth Factor 2; Growth Hormone; Growth Substances; Humans; Hyperglycemia; Insulin Resistance; Insulin-Like Growth Factor I; Receptors, Somatotropin; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

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

The renoprotective effect of captopril on progression of diabetic nephropathy was demonstrated by the Collaborative Study Group Captopril Trial and might be independent of blood pressure. Because angiotensin II is known to stimulate the prosclerotic cytokine, transforming growth factor-beta (TGF-beta), we postulated that the renoprotective effect may be due to inhibition of TGF-beta1 production. TGF-beta1 levels were measured in serum at baseline and 6 months from patients in the captopril trial. TGF-beta1 analyses were performed on all available patient sera. Analysis was performed between the percent change in TGF-beta1 levels during the first 6 months versus the percent change in glomerular filtration rate (GFR) in the subsequent 2 years. TGF-beta1 levels increased by 11% (P = 0. 003) in the placebo group (n = 24), whereas there was a decrease of 14% (P = 0.01) in the captopril group (n = 34). There was an inverse correlation between the percent change in TGF-beta1 levels during the first 6 months and the percent change in GFR over the ensuing 2-year period in patients from both the placebo (r = -0.55, P = 0. 005) and captopril groups (r = -0.45, P = 0.008). In patients with initial GFR below 75 mL/min, there was an even stronger correlation in percent change in TGF-beta1 levels and percent change in GFR in both placebo (n = 9, r = -0.69, P = 0.03) and captopril groups (n = 21, r = -0.73, P = 0.0001). Our data suggest that captopril decreases TGF-beta1 levels in diabetic nephropathy and that changes in TGF-beta1 levels may predict the course of diabetic nephropathy.

Topics: Adult; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Blood Pressure; Captopril; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Female; Follow-Up Studies; Glomerular Filtration Rate; Glycated Hemoglobin; Humans; Hypertension, Renal; Kidney Function Tests; Male; 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

To investigate the effects of ibuprofen on cardiac fibrosis in a rat model of type 1 diabetes.. The diabetic model was established by injecting streptozotocin into the rats. Then, ibuprofen or pioglitazone was given by gavage for 8 weeks. The cardiac fibrosis was assessed, and the major components of the renin-angiotensin system, the transforming growth factor β1 (TGF-β1) and the mammalian target of rapamycin (mTOR), were evaluated by histopathological, immunohistochemical, Western blot analysis or ELISA assay.. Obvious cardiac fibrosis was detected in the diabetic group and was alleviated by ibuprofen treatment. Angiotensin-converting enzyme (ACE), angiotensin (Ang) II and AngII type 1 receptor (AT1-R) levels were higher, and ACE2, Ang(1-7) and Mas receptor (Mas-R) were lower in the diabetic group. The ratio of ACE to ACE2 was raised in the diabetic group. All these changes were ameliorated by ibuprofen. TGF-β1 and mTOR were raised in the hearts of the diabetic group and were attenuated by ibuprofen treatment. There was no significant difference between the ibuprofen and the pioglitazone groups.. Ibuprofen could ameliorate the cardiac fibrosis in diabetic rats by reduction of the ACE/AngII/AT1-R axis and enhancement of the ACE2/Ang(1-7)/Mas-R axis, leading to a decrease in TGF-β1 and mTOR.

Topics: Angiotensin-Converting Enzyme 2; Animals; Cardiotonic Agents; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Down-Regulation; Fibrosis; Ibuprofen; Male; Myocardium; Peptidyl-Dipeptidase A; Rats, Sprague-Dawley; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Up-Regulation

Fibroblast growth factor 21 (FGF21) is an important regulator in glucose and lipid metabolism, and has been considered as a potential therapy for diabetes. The effect of FGF21 on the development and progression of diabetes-induced pathogenic changes in the aorta has not currently been addressed. To characterize these effects, type 1 diabetes was induced in both FGF21 knockout (FGF21KO) and C57BL/6 J wild type (WT) mice via multiple-dose streptozotocin injection. FGF21KO diabetic mice showed both earlier and more severe aortic remodeling indicated by aortic thickening, collagen accumulation and fibrotic mediator connective tissue growth factor expression. This was accompanied by significant aortic cell apoptosis than in WT diabetic mice. Further investigation found that FGF21 deletion exacerbated aortic inflammation and oxidative stress reflected by elevated expression of tumor necrosis factor α and transforming growth factor β, and the accumulation of 3-nitrotyrocine and 4-Hydroxynonenal. FGF21 administration can reverse the pathologic changes in FGF21KO diabetic mice. These findings demonstrate that FGF21 deletion aggravates aortic remodeling and cell death probably via exacerbation of aortic inflammation and oxidative stress. This marks FGF21 as a potential therapy for the treatment of aortic damage due to diabetes.

Topics: Aldehydes; Animals; Aorta; Aortic Diseases; Apoptosis; Collagen; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Fibroblast Growth Factors; Fibrosis; Gene Deletion; Genetic Predisposition to Disease; Male; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase Type III; Oxidative Stress; Phenotype; Signal Transduction; Time Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Tyrosine; Vascular Remodeling

Impairment of coronary flow reserve (CFR) has been generally demonstrated in diabetic patients and animals with microvascular complications but without obvious obstructive coronary atherosclerosis. There have been few studies investigating CFR in cases of relatively well-controlled therapy. The purpose of this study is to evaluate the effect of treatment with a Sphingosine-1-phosphate (S1P) receptor potent agonist, FTY720, on early diabetic rats in terms of CFR. METHODS AND RESULTS: Male Sprague-Dawley (SD) rats were divided into 3 groups: (1) streptozotocin-uninjected rats (control rats); (2) streptozotocin-injected hyperglycemic rats (diabetic group); and (3) FTY720-fed and streptozotocin-injected hyperglycemic rats. FTY720 (1.25 mg/kg per day orally) was administrated for 9 weeks in SD rats (from 6 weeks old to 15 weeks old). CFR was evaluated by (13)NH3-positron emission tomography. No obvious pathological changes of macrovascular atherosclerosis were observed in each group. Diabetic rats had impaired CFR compared with the control group (1.39±0.26 vs. 1.94±0.24, P<0.05). Treatment with FTY720 for 9 weeks attenuated the heart histological changes and improved CFR in 32% of diabetic rats (1.84±0.36 vs. 1.39±0.26, P<0.05).. In summary, long-term therapy with the Sphingosine-1-phosphate receptor agonist, FTY720, improved CFR by attenuating the heart histological changes, and it might have a beneficial effect on coronary microvascular function in diabetic rats.

Topics: Ammonia; Animals; Blood Glucose; Capillaries; Cell Adhesion Molecules; Collagen; Coronary Circulation; Coronary Disease; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Drug Evaluation, Preclinical; Fingolimod Hydrochloride; Gene Expression Regulation; Interleukin-6; Lysophospholipids; Male; Microcirculation; Myocardium; Nitrogen Radioisotopes; Positron-Emission Tomography; Propylene Glycols; Rats; Rats, Sprague-Dawley; Receptors, Lysosphingolipid; Sphingosine; Transforming Growth Factor beta

To verify if innate immunity, and namely the assembly of terminal complement complex (TCC) could be involved in the development of early diabetic vascular damage.. At first in 2 groups of diabetic or non-diabetic Wistar rats the occurrence of basal or stimulated stable adherence to the endothelial layer and extravasation of circulating fluorescently-labelled leukocytes was assessed by using an in vivo videomicroscopy technique. In a second part of the study, the development of vascular damage in short term diabetes was studied in the genetically C6 deficient rats of the PVG strain, and compared with those observed in the wild-type C6 sufficient animals. Here, the analysis of mesentery vascular expression of mRNA for vascular cell adhesion molecule (VCAM)-1, transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), and platelet-derived growth factor (PDGF), the evaluation of intravascular protein levels of VCAM-1, TGF-β, CTGF, proliferative cell nuclear antigen (PCNA), as well as the assessment of structural changes and Complement components deposition at the mesentery arterial vascular wall were also performed.. Leukocyte trafficking, mesentery arteries hypertrophy, extracellular matrix deposition, local vascular gene and protein expression of VCAM-1, TGF-β, CTGF and PCNA, as well as PGDF gene expression were all increased by short term diabetes, but all significantly reduced in the C6 deficient diabetic animals, thus suggesting an active role for TCC in the development of vascular inflammation in the early phases of experimental diabetes.

Topics: Analysis of Variance; Animals; Atherosclerosis; Blood Pressure; Complement Activation; Complement C3; Complement C6; Complement C9; Complement Membrane Attack Complex; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Extracellular Matrix; Gene Expression Regulation; Hypertrophy; Immunity, Innate; Inflammation; Inflammation Mediators; Leukocyte Rolling; Male; Mesenteric Arteries; Microscopy, Video; Platelet-Derived Growth Factor; Proliferating Cell Nuclear Antigen; Rats; Rats, Transgenic; Rats, Wistar; Time Factors; Transforming Growth Factor beta; Vascular Cell Adhesion Molecule-1

Excess accumulation of vascular extracellular matrix (ECM) is an important pathological process in cardiovascular diseases including diabetes-associated atherosclerosis. We explored how a recently identified molecule, cell division autoantigen 1 (CDA1), influences the profibrotic TGF-beta pathway leading to vascular ECM accumulation.. Expression levels of genes encoding for CDA1, TGF-beta and connective tissue growth factor (CTGF) were examined in aorta from Apoe(-/-) mice with or without diabetes. We used retroviral and adenoviral constructs to knockdown or overexpress Tspyl2, the gene encoding CDA1, in mouse vascular smooth muscle cells (VSMCs) with or without TGF-beta treatment in order to demonstrate the role of CDA1 in TGF-beta signalling.. In vivo studies indicated that the mRNA levels of CDA1-encoding gene Tspyl2 and protein levels of CDA1 were elevated in the aorta of diabetic Apoe(-/-) mice, accompanied by increased levels of Tgf-beta (also known as Tgfb1), Ctgf and ECM accumulation. In vitro studies in vascular cells showed that TGF-beta treatment rapidly increased CDA1 protein levels, which then amplified TGF-beta signalling leading to upregulation of ECM genes. Knockdown of CDA1-encoding gene Tspyl2 to reduce cellular CDA1 level markedly attenuated TGF-beta-stimulated MAD homologue 3 (drosophila; SMAD3) phosphorylation and transcriptional activities. CDA1 overproduction increased and Tspyl2 knockdown decreased expression of TGF-beta receptor type I, TbetarI (also known as Tgfbr1), but not TGF-beta receptor type II, TbetarII (also known as Tgfbr2), providing a mechanism for CDA1's action in modulating TGF-beta signalling. Knockdown of CDA1-encoding gene Tspyl2 also blocked the profibrotic effect of TGF-beta in VSMCs.. CDA1 plays an important role in vascular ECM accumulation by amplifying TGF-beta signalling. This is critical for the profibrotic effect of TGF-beta in the vasculature. CDA1 is therefore a potential target for attenuating vascular ECM accumulation caused by enhanced TGF-beta action, as seen in diabetic atherosclerosis.

Topics: Animals; Aorta; Atherosclerosis; Autoantigens; Blood Glucose; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Extracellular Matrix; Gene Expression Regulation; Genes, Reporter; Glycated Hemoglobin; Lipoproteins; Luciferases; Mice; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Transforming Growth Factor beta

The multiligand RAGE (receptor for advanced glycation end products) contributes to atherosclerosis in apolipoprotein (Apo)E-null mice.. To delineate the specific mechanisms by which RAGE accelerated atherosclerosis, we performed Affymetrix gene expression arrays on aortas of nondiabetic and diabetic ApoE-null mice expressing RAGE or devoid of RAGE at nine weeks of age, as this reflected a time point at which frank atherosclerotic lesions were not yet present, but that we would be able to identify the genes likely involved in diabetes- and RAGE-dependent atherogenesis.. We report that there is very little overlap of the genes that are differentially expressed both in the onset of diabetes in ApoE-null mice, and in the effect of RAGE deletion in diabetic ApoE-null mice. Pathway-Express analysis revealed that the transforming growth factor-beta pathway and focal adhesion pathways might be expected to play a significant role in both the mechanism by which diabetes facilitates the formation of atherosclerotic plaques in ApoE-null mice, and the mechanism by which deletion of RAGE ameliorates this effect. Quantitative polymerase chain reaction studies, Western blotting, and confocal microscopy in aortic tissue and in primary cultures of murine aortic smooth muscle cells supported these findings.. Taken together, our work suggests that RAGE-dependent acceleration of atherosclerosis in ApoE-null mice is dependent, at least in part, on the action of the ROCK1 (rho-associated protein kinase 1) branch of the transforming growth factor-beta pathway.

Topics: Animals; Aorta; Aortic Diseases; Apolipoproteins E; Atherosclerosis; Blotting, Western; Cell Movement; Cell Proliferation; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Disease Progression; Enzyme Activation; Focal Adhesions; Gene Expression Profiling; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Confocal; Muscle, Smooth, Vascular; Oligonucleotide Array Sequence Analysis; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Reverse Transcriptase Polymerase Chain Reaction; rho-Associated Kinases; Signal Transduction; Thrombospondin 1; Time Factors; Transforming Growth Factor beta

CCN3 belongs to the CCN family, which constitutes multifunctional secreted proteins that act as matrix cellular regulators. We investigated the pathophysiological roles of CCN3 in the vessels.. We examined the effects of CCN3 on the proliferation and migration of rat vascular smooth muscle cells (VSMC). CCN3 knockout mice were created, and vascular phenotypes and neointimal hyperplasia induced by photochemically induced thrombosis were investigated. CCN3 suppressed the VSMC proliferation induced by fetal bovine serum. The neutralizing antibody for transforming growth factor-beta did not affect the growth inhibitory effect of CCN3. Moreover, CCN3 enhanced the mRNA expression of cyclin-dependent kinase inhibitors, p21 and p15. Gamma secretase inhibitor, an inhibitor of Notch signaling, partially inhibited the enhanced expression of p21 induced by CCN3. CCN3 also inhibited the VSMC migration. Finally, the histopathologic evaluation of the arteries 21 days after the endothelial injury revealed a 6-fold enhancement of neointimal thickening in the null mice compared with the wild-type mice.. CCN3 suppresses neointimal thickening through the inhibition of VSMC migration and proliferation. Our findings indicate the involvement of CCN3 in vascular homeostasis, especially on injury, and the potential usefulness of this molecule in the modulation of atherosclerotic vascular disease.

Topics: Amyloid Precursor Protein Secretases; Animals; Aorta; Cell Cycle; Cell Movement; Cell Proliferation; Cells, Cultured; Cyclin-Dependent Kinase Inhibitor p15; Cyclin-Dependent Kinase Inhibitor p21; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Femoral Artery; Genotype; Hyperplasia; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nephroblastoma Overexpressed Protein; Phenotype; Protease Inhibitors; Rats; Rats, Wistar; Receptors, Notch; Recombinant Proteins; Signal Transduction; Thrombosis; Time Factors; Transfection; Transforming Growth Factor beta

Peripheral blood CD34(+) cells from diabetic patients demonstrate reduced vascular reparative function due to decreased proliferation and diminished migratory prowess, largely resulting from decreased nitric oxide (NO) bioavailability. The level of TGF-beta, a key factor that modulates stem cell quiescence, is increased in the serum of type 2 diabetic patients. We asked whether transient TGF-beta1 inhibition in CD34(+) cells would improve their reparative ability.. To inhibit TGF-beta1 protein expression, CD34(+) cells were treated ex vivo with antisense phosphorodiamidate morpholino oligomers (TGF-beta1-PMOs) and analyzed for cell surface CXCR4 expression, cell survival in the absence of added growth factors, SDF-1-induced migration, NO release, and in vivo retinal vascular reparative ability.. TGF-beta1-PMO treatment of diabetic CD34(+) cells resulted in increased expression of CXCR4, enhanced survival in the absence of growth factors, and increased migration and NO release as compared with cells treated with control PMO. Using a retinal ischemia reperfusion injury model in mice, we observed that recruitment of diabetic CD34(+) cells to injured acellular retinal capillaries was greater after TGF-beta1-PMO treatment compared with control PMO-treated cells.. Transient inhibition of TGF-beta1 may represent a promising therapeutic strategy for restoring the reparative capacity of dysfunctional diabetic CD34(+) cells.

Topics: Animals; Antigens, CD34; Capillaries; Cell Survival; Diabetes Mellitus; Diabetic Angiopathies; Diabetic Retinopathy; Flow Cytometry; Hematopoietic Stem Cells; Humans; Mice; Morpholines; Morpholinos; Nitric Oxide; Receptors, CXCR4; Reperfusion Injury; Transforming Growth Factor beta; Transforming Growth Factor beta1

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

Bone marrow mesenchymal stem cells (MSC) mediate their protection by paracrine mechanism under ischemic conditions and anoxic pre-conditioning (AP) of MSC strongly enhances their survival and regenerative capacity. However, there is no report about the therapeutic potency of MSC transplantation on diabetic cardiomyopathy (DCM), an important cause of heart failure.. Four months after streptozotocin injection, diabetic rats were randomly given an intramyocardial injection of one of the following: DMEM, MSC, or AP-MSC (no.=10 for each group). Two weeks after transplantation, MSC, especially AP-MSC greatly increased the fractional shortening of diabetic heart (p<0.01, respectively). AP-MSC increased the capillary density of diabetic myocardium and attenuated myocardial fibrosis (p<0.01, respectively) by increasing the activity of matrix metalloproteinase-2 and inhibitiing transforming growth factor beta-1 (p<0.01, respectively). AP-MSC are anti-apoptotic in the rat DCM model, possibly mediated through cardiac upregulation of Bcl-2/Bax ratio (p<0.05) and inhibiting the expression and activation of caspase- 3 (p<0.01).. Intramyocardial transplantation of MSC has a protective effect on diabetic myocardium and anoxic pre-conditioning can enhance this protective effect. AP-MSC transplantation improved cardiac function in the rat DCM model, possibly through an anti-apoptotic effect on diabetic myocarium and attenuation of cardiac remodeling.

Topics: Animals; Apoptosis; Bone Marrow Cells; Bone Marrow Transplantation; Cardiomyopathies; Cell Hypoxia; Cells, Cultured; Coronary Vessels; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Ischemic Preconditioning, Myocardial; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Age-related medial calcification (elastocalcinosis) of large arteries is accelerated in diabetes and appears mainly in distal arteries. The aim was to devise a rat model of elastocalcinosis in association with diabetes to examine the hypothesis that diabetes accelerates vascular calcification experimentally.. Male Wistar rats received a high fat diet during 2 months followed by a low dose of streptozotocin to induce diabetes (D). Elastocalcinosis was facilitated by 3 weeks of treatment with warfarin and vitamin K (WVK). We started WVK treatment 1 week (D4WVK) and 4 weeks (D7WVK) after the injection of streptozotocin and in age-matched healthy rats. Measurements of hemodynamic and metabolic parameters, aortic and femoral calcium content, and immunohistochemistry for alkaline phosphatase, osteopontin, tumor necrosis factor (TNF)-alpha, and transforming growth factor (TGF)-TGF-beta were performed.. Three weeks of WVK treatment alone did not increase the calcium content in the aorta and femoral arteries. However, in the D7WVK group, femoral calcification, but not aortic calcium content, increased significantly as compared to the WVK group. This response was not observed in the D4WVK group. In femoral arteries, strong immunostaining for alkaline phosphatase and osteopontin was observed in the D7WVK group. TNF-alpha and TGF-beta expressions were mainly localized in the adventitia of arteries from diabetic rats.. We have established a model of accelerated elastocalcinosis in diabetes related to its duration and localized in distal arteries. The modification of local protein expression is also in accordance with clinical data, suggesting that this model could be useful to investigate mechanisms related to this important clinical macrovascular complication of diabetes.

Topics: Alkaline Phosphatase; Animals; Aorta; Arteriosclerosis; Calcinosis; Calcium; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Femoral Artery; Immunohistochemistry; Male; Models, Animal; Osteopontin; Rats; Rats, Wistar; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vitamin K; Warfarin

Vascular calcification is common in diabetes but the pathogenesis is poorly understood.. To investigate the pathogenesis, we first examined the histology of inferior epigastric arteries from diabetic and non-diabetic patients undergoing a renal transplant. To examine the role of hyperglycaemia, bovine vascular smooth muscle cells (BVSMCs) were incubated with normal (5 mM) or high glucose (25 mM) for 48 or 72 h.. The results demonstrated that diabetic patients, compared with non-diabetic patients, had significantly greater calcification and increased expression of the bone matrix proteins osteopontin, type I collagen, bone sialoprotein and alkaline phosphatase (ALP). The in vitro studies demonstrated that high glucose increased the expression of the osteoblast transcription factor core binding factor alpha subunit 1 (Cbfa1) and its downstream protein osteocalcin by 1.9-fold and 1.8-fold, respectively, and ALP activity by 1.5-fold. These findings were blunted in the presence of an inhibitor to protein kinase C. High glucose also significantly enhanced calcification in BVSMC in a time-dependent manner (2.20 +/- 0.50 vs 1.35 +/- 0.55 micromol/mg, day 7; 5.04 +/- 1.35 vs 3.12 +/- 0.92 micromol/mg, day 14; P < 0.05). High glucose also induced the secretion of bone morphogenetic protein-2, a known osteoinductive factor, and further increased the secretion normally seen during calcification by 43% at day 7 and 57% at day 14.. These results demonstrate that vascular calcification in patients with diabetes is a cell-mediated process characterized by a phenotypic change of VSMCs to osteoblast-like cells with increased bone matrix protein expression, and that hyperglycaemia may directly induce these changes.

Topics: Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Calcinosis; Cattle; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Diabetic Angiopathies; Glucose; Humans; Muscle, Smooth, Vascular; Transforming Growth Factor beta; Vascular Diseases

The pathological accumulation of extracellular matrix is a characteristic feature of diabetic cardiomyopathy that is directly related to a loss of function. Tranilast (n-[3,4-anthranilic acid), used for the treatment of fibrotic skin diseases, has also been shown to inhibit transforming growth factor-beta (TGF-beta)-induced matrix production in kidney epithelial cells.. To investigate the effects of tranilast in the diabetic heart, we examined its effects in cultured cardiac fibroblasts and then assessed its effects in (mRen-2)27 diabetic rats with established disease (8 weeks after streptozotocin).. In vitro studies demonstrated a 58% reduction in TGF-beta1-induced 3[H]-hydroxyproline incorporation with tranilast 30 microM (p<0.01). At 16 weeks, diabetes in the Ren-2 rat was associated with increased cardiac fibrosis and evidence of TGF-beta1 activation, as measured by the abundance of phosphorylated Smad2. Despite persistent hyperglycaemia and hypertension, tranilast attenuated cardiac fibrosis by 37% (p<0.05) in association with reduction in phospho-Smad2 (p<0.01).. These findings indicate that tranilast has antifibrotic actions in the Ren-2 model of experimental diabetic cardiac disease by mechanisms that might attributable to reduced TGF-beta activity.

Topics: Animals; Collagen; Diabetes Mellitus, Experimental; Diabetic Angiopathies; DNA-Binding Proteins; Extracellular Matrix; Female; Fibroblasts; Fibrosis; Heart; Myocardium; ortho-Aminobenzoates; Phosphorylation; Rats; Smad2 Protein; Trans-Activators; Transforming Growth Factor beta; Transforming Growth Factor beta1

While it is thought that advanced glycation end products (AGEs) act by stimulating transforming growth factor (TGF)-beta to mediate diabetic injury, we report that AGEs can activate TGF-beta signaling, Smads, and mediate diabetic scarring directly and independently of TGF-beta. AGEs activate Smad2/3 in renal and vascular cells at 5 min, peaking over 15-30 min before TGF-beta synthesis at 24 h and occurs in TGF-beta receptor I and II mutant cells. This is mediated by RAGE and ERK/p38 mitogen-activated protein kinases (MAPKs). In addition, AGEs also activate Smads at 24 h via the classic TGF-beta-dependent pathway. A substantial inhibition of AGE-induced Smad activation and collagen synthesis by ERK/p38 MAPK inhibitors, but not by TGF-beta blockade, suggests that the MAPK-Smad signaling crosstalk pathway is a key mechanism in diabetic scarring. Prevention of AGE-induced Smad activation and collagen synthesis by overexpression of Smad7 indicates that Smad signaling may play a critical role in diabetic complications. This is further supported by the findings that activation of Smad2/3 in human diabetic nephropathy and vasculopathy is associated with local deposition of AGEs and up-regulation of RAGE. Thus, AGEs act by activating Smad signaling to mediate diabetic complications via both TGF-beta-dependent and -independent pathways, shedding new light on the pathogenesis of diabetic organ injury.

Topics: Cells, Cultured; Collagen; Diabetic Angiopathies; Diabetic Nephropathies; DNA-Binding Proteins; Enzyme Inhibitors; Glycation End Products, Advanced; Humans; Kinetics; Mitogen-Activated Protein Kinases; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Signal Transduction; Smad2 Protein; Smad3 Protein; Smad7 Protein; Trans-Activators; Transforming Growth Factor beta

Genetic background appears to modulate the development of diabetic vascular complications. In particular, polymorphisms in the ACE gene have been associated with diabetic nephropathy and, in some studies, macrovascular complications. However, the links between ACE gene polymorphism and factors implicated in diabetes complications remain unknown. The aim of this study was to determine whether the ACE genotype could modify factors, such as transforming growth factor (TGF)-beta 1, involved in the complications of diabetes. For this purpose, congenic rats (L.BNAce10), differing from the LOU strain in only a small segment of chromosome 10 containing the ACE locus, were generated. These congenic rats have plasma ACE levels twice as high as the donor strain. Diabetes was induced in rats of both strains, and its effects on ACE and TGF-beta 1 expressions were evaluated in lungs and kidneys. In lung, the main source of ACE production, ACE mRNA levels and activity were higher in L.BNAce10 rats than in LOU rats. Diabetes increased ACE lung expression in rats of both strains in a similar manner. TGF-beta 1 expression was also higher in lungs of L.BNAce10 compared with LOU rats and was also increased by diabetes. Furthermore, a strong correlation was found between TGF-beta 1 and ACE expressions. In renal arterioles, ACE and TGF-beta mRNA expressions were higher in L.BNAce10 rats than LOU rats (both diabetic and nondiabetic). In these vessels, there was also a correlation between ACE and TGF-beta 1 expressions. Urine TGF-beta 1 concentration depended on the genotype and was further increased by diabetes. These results show that TGF-beta 1 expression is correlated with ACE expression and suggest that this growth factor could be a link between ACE gene polymorphism and diabetic vascular complications.

Topics: Animals; Blood Pressure; Chromosome Mapping; Crosses, Genetic; Diabetic Angiopathies; Diabetic Nephropathies; Gene Expression Regulation, Enzymologic; Genetic Markers; Genotype; Heart Rate; Peptidyl-Dipeptidase A; Rats; Rats, Inbred BN; Rats, Mutant Strains; Renin; RNA, Messenger; Transcription, Genetic; Transforming Growth Factor beta

Macrovascular complications in diabetes are associated with exaggerated growth responses of vascular smooth muscle cells. We studied the effect of high glucose media on the growth responses of vascular smooth muscle cells from the left anterior descending (LAD) coronary artery of young sheep. Experiments were conducted in DMEM containing 5.5 or 25 mmol/l glucose and mitogenic responses assessed by 3H-thymidine incorporation. In the absence of growth factors there was a slight and variable response to high glucose but the maximum response to platelet derived growth factor-bb (PDGF-bb) (100 ng/ml) was increased more than 2-fold. Transforming growth factor-beta1 (1 ng/ml) caused a 100% increase of the PDGF-bb response in both normal and high glucose media. The acute stimulatory effect of high glucose was not affected by pre-incubation of the cells for 24 h in the high glucose medium. The mitogenic response occurring in the presence of PDGF-bb and high glucose was totally inhibited by the tyrosine kinase inhibitors (imatinib and genistein) and could not be mimicked by increasing diacylglycerol in low glucose media with the diacylglycerol kinase inhibitor, R59949. In conclusion, high glucose, per se, only very weakly stimulates smooth muscle cell growth but it interacts positively to potentiate the responses to the vascular derived growth factors PDGF and TGF-beta1. The effect of high glucose is transduced via receptor tyrosine kinases and may not involve diacylglycerol that is subject to diacylglycerol kinase catabolism. The data provide explanations for the accelerated vascular smooth muscle cell proliferation in diabetes.

Topics: Animals; Becaplermin; Cell Division; Cells, Cultured; Coronary Vessels; Diabetic Angiopathies; Glucose; Muscle, Smooth, Vascular; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Sheep; Thymidine; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tunica Media

TGF-beta-induced gene-h3 (beta ig-h3) is an adhesive molecule that interacts with integrins. Because TGF-beta plays an important role in diabetic complications and beta ig-h3 serves as a cell substrate, we hypothesized that diabetic conditions might increase beta ig-h3 synthesis in vascular smooth muscle cells (VSMCs), which may subsequently contribute to the pathogenesis of diabetic angiopathy. The concentrations of beta ig-h3 and TGF-beta were measured in conditioned media using an enzyme-linked immunosorbent assay. An immunohistochemical study showed that beta ig-h3 was expressed in the VSMCs and the matrix of rat aortas. TGF-beta stimulated beta ig-h3 production, and high glucose induced beta ig-h3 as well as TGF-beta production in the VSMCs. The high glucose-induced beta ig-h3 expression was almost entirely blocked by an anti-TGF-beta antibody. beta ig-h3 protein mediated the adhesion, spreading, migration, and proliferation of rat VSMCs. These results suggest that the high glucose-induced beta ig-h3 in VSMCs regulates VSMC functions and may play an important role in diabetic angiopathy.

Topics: Animals; Aorta, Thoracic; Cell Adhesion; Cell Division; Cell Movement; Cells, Cultured; Diabetic Angiopathies; Extracellular Matrix Proteins; Glucose; Growth Substances; Humans; Intercellular Signaling Peptides and Proteins; Male; Myocytes, Smooth Muscle; Peptides; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

The growth factors transforming growth factor-B (TGF-B) and epidermal growth factor (EGF) have both been implicated in the hypertrophic structural changes in the vasculature that are characteristic features of both human and experimental diabetes. Recently, tranilast (N(3,4-dimethoxycinnamoyl)anthranilic acid), a drug used in the treatment of allergic and dermatological diseases, has also been reported to inhibit transforming growth factor-B (TGF-B)-mediated collagen formation. However, its effects on vascular hypertrophy in diabetes are unknown. The present study thus sought to determine the effects of tranilast on both TGF-B and EGF expression and mast cells in mediating the trophic vascular changes in experimental diabetes.. Vessel morphology, growth factors and collagen gene expression and matrix deposition were examined in the mesenteric arteries of control rats treated with or without tranilast, and streptozotocin-induced diabetic Sprague-Dawley rats treated with or without tranilast (200 mg/kg/day) during a 3-week period.. Compared with control animals, diabetic rats had significantly increased vessel weight, wall: lumen ratio, ECM accumulation, gene expression of TGF-B1, EGF, and both alpha1 (I) and alpha1 (IV) collagen. Tranilast treatment did not influence plasma glucose or systemic blood pressure. However, tranilast significantly reduced mesenteric weight, wall: lumen ratio and matrix deposition and also attenuated the overexpression of TGF-B1, EGF, and both alpha1 (I) and alpha1 (IV) collagen mRNA in diabetic rats.. These findings indicate that tranilast ameliorates pathological vascular changes observed in experimental diabetes in association with reduced growth factor expression independent of blood glucose or systemic blood pressure.

Topics: Animals; Base Sequence; Blood Vessels; Collagen; Diabetes Mellitus, Experimental; Diabetic Angiopathies; DNA Primers; Epidermal Growth Factor; Gene Expression Regulation; Growth Substances; Hypertrophy; Immunohistochemistry; Male; ortho-Aminobenzoates; Platelet Aggregation Inhibitors; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta

Diabetes and renal failure have been associated with extremely high restenosis rates following successful angioplasty, resulting in increased morbidity and mortality. Advanced glycosylation end products (AGEs) accumulate in vascular tissues with aging and at an accelerated rate in diabetes and renal failure. AGEs are particularly abundant at sites of atherosclerotic lesions. AGEs interact with specific receptors (RAGE) present on all cells relevant to the restenosis process including inflammatory cells and smooth muscle cells. AGEs-RAGE interaction in vessel wall may lead to inflammation, smooth muscle cell proliferation, and extracellular matrix production, culminating in exaggerated intimal hyperplasia and restenosis. Following arterial injury, the interaction of AGEs with monocytes expressing RAGE can promote migration of inflammatory cells into the lesion and subsequent release of growth factors and cytokines. Binding of AGEs-RAGE on smooth muscle cells increases chemotactic migration and cellular proliferation. AGEs trigger the generation of reactive oxygen species, and upregulate the multifunctional transcription factor NF-kappa B. Finally, AGEs can augment extracellular matrix production by upregulating transforming growth factor-beta. Thus, accumulation of AGEs in vessel wall provides a common mechanism for the high restenosis rates of patients with diabetes and renal failure.

Topics: Angioplasty, Balloon, Coronary; Coronary Disease; Coronary Restenosis; Cytokines; Diabetic Angiopathies; Diabetic Nephropathies; Extracellular Matrix; Glycation End Products, Advanced; Growth Substances; Humans; Hyperplasia; Kidney Failure, Chronic; Models, Biological; Muscle, Smooth, Vascular; NF-kappa B; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Stents; Transforming Growth Factor beta; Tunica Intima; Tunica Media

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

The primary etiologic factor in diabetic glomerulosclerosis appears to be an overproduction of transforming growth factor-beta by mesangial cells, which in turn reflects a hyperglycemically mediated overactivation of protein kinase C (PKC) throughout the glomerulus. Membrane-active antioxidants, fish oil, and angiotensin-converting enzyme inhibitors can act to down-regulate glomerular PKC activity, via a variety of mechanisms that may include activation of diacylglycerol kinase and suppression of phosphatidate phosphohydrolase, support of endothelial nitric oxide and heparan sulfate production, inhibition of thromboxane and angiotensin synthesis/activity, and correction of glomerular hypertension. The beneficial impact of these measures on vascular endothelial function may be of more general utility in the prevention of diabetic complications such as retinopathy, neuropathy, and atherosclerosis. Adjunctive use of gamma-linolenic acid is indicated for prevention of neuropathy, and it is conceivable that bioactive chromium will have protective activity not solely attributable to improved glycemic control. Re-establishing euglycemia must clearly remain the core strategy for preventing diabetic complications, but when glycemic control remains suboptimal, practical, safe measures are at hand for decreasing risk.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Antioxidants; Diabetic Angiopathies; Diabetic Nephropathies; Enzyme Activation; Fish Oils; Heparitin Sulfate; Humans; Hyperglycemia; Kidney Glomerulus; Lipid Peroxidation; Models, Biological; Nitric Oxide; Protein Kinase C; Thromboxane A2; Transforming Growth Factor beta

The purpose of this study was to assess the role of transforming growth factor (TGF)-beta1 in the development of diabetes-associated mesenteric vascular hypertrophy and in the antitrophic effect of angiotensin converting enzyme inhibitors.. Streptozotocin-induced diabetic and control Sprague-Dawley rats were randomly allocated to treatment with the angiotensin converting enzyme inhibitor ramipril or to no treatment and were killed 1 or 3 weeks after the streptozotocin injection. Blood was collected and mesenteric vessels removed. Mesenteric vascular weight was measured and TGF-beta1 and alpha1 (type IV) collagen messenger (m)RNA levels were analysed by Northern analysis. Immunohistochemical analyses for TGF-beta1 and type IV collagen were also performed.. The diabetic rats had increased mesenteric vessel weight at 3 weeks but not at 1 week and a concomitant rise in mesenteric TGF-beta1 and in alpha1 (type IV) collagen mRNA levels. Ramipril treatment attenuated mesenteric vessel hypertrophy and prevented the increase in TGF-beta1 and alpha1 (type IV) collagen mRNA levels after 3 weeks of diabetes. The immunohistochemical analysis revealed that diabetes was associated with increased TGF-beta1 and type IV collagen protein and extracellular matrix accumulation in mesenteric vessels, and this increase was reduced by ramipril treatment.. These results support the concept that TGF-beta is involved in the changes associated with diabetic vascular disease, and suggest a mechanism by which angiotensin converting enzyme inhibitors exert their antitrophic effects.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Glucose; Blood Pressure; Blotting, Northern; Body Weight; Collagen; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Gene Expression; Immunohistochemistry; Male; Ramipril; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Vascular Diseases

Vascular disease is now the major cause of morbidity and mortality in the diabetic population. Our group explored the vascular changes associated with experimental diabetes and examined whether these changes can be ameliorated by angiotensin-converting enzyme (ACE) inhibition. The ACE inhibitor perindopril (PE) was administered to streptozotocin-induced diabetic rats for 24 weeks. At death, mesenteric vessels were perfused in vivo followed by assessment of the vascular architecture by quantitative histomorphometry. In a subgroup of animals, RNA was extracted from the mesenteric vasculature for assessment of gene expression of the prosclerotic cytokine, transforming growth factor beta 1 (TGFbeta1), and the matrix protein, type IV collagen. Diabetes was associated with smooth muscle hypertrophy and extracellular matrix (ECM) accumulation. ECM accumulation, particularly collagen deposition, was observed in the medial and adventitial layers. ACE inhibition prevented mesenteric vascular hypertrophy after 24 weeks of diabetes. In addition, overexpression of TGFbeta1 in the vessels of diabetic animals was prevented by PE treatment. Similarly, type IV collagen mRNA levels were increased in diabetic vessels, and this overexpression was also prevented by PE therapy. In summary, ACE inhibition attenuates many of the vascular changes observed in experimental diabetes and may have important clinical implications as a vasoprotective agent in human diabetes.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Vessels; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Hypertrophy; Indoles; Male; Perindopril; Rats; Rats, Sprague-Dawley; RNA, Messenger; Splanchnic Circulation; 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

Endothelial cells are known to secrete various antiproliferative and vasodilating factors. Although injury of endothelial cells has been postulated as an initial trigger of the progression of atherosclerosis in patients with diabetes, the mechanisms of endothelial injury in diabetes are not yet clarified. Therefore, it is important to know the effects of high glucose on the factors that may influence endothelial cell growth. A novel member of endothelium-specific growth factors, hepatocyte growth factor (HGF), is produced in vascular cells. To investigate the effects of high glucose on vascular cells, we examined 1) the effects of high glucose on endothelial cell and vascular smooth muscle cell (VSMC) growth and 2) the effects of high glucose on local HGF production in endothelial cell and VSMC. Treatment of human aortic endothelial cell with a high concentration of D-glucose, but not mannitol and L-glucose, resulted in a significant decrease in cell number. Interestingly, addition of recombinant HGF attenuated high D-glucose-induced endothelial cell death. Therefore, we measured local HGF secretion of endothelial cell. Importantly, local HGF production was significantly decreased by high D-glucose treatment. In contrast, high D-glucose treatment resulted in a significant increase in the number of human aortic VSMCs, whereas local HGF production was significantly decreased in accordance with increase in D-glucose concentration. No significant changes in numbers were observed in VSMC treated with high mannitol and L-glucose. We also studied the mechanisms of local HGF suppression by high D-glucose. High D-glucose treatment stimulated transforming growth factor-beta (TGF-beta) concentration in endothelial cell and VSMC. Decreased local vascular HGF production was abolished by addition of anti-TGF-beta antibody. As TGF-beta inhibited local HGF production in endothelial cell and VSMC, increased TGF-beta induced by high D-glucose may suppress local HGF production. This study demonstrated that high D-glucose induced endothelial cell death, stimulated VSMC growth, and decreased local HGF production through the stimulation of TGF-beta production both in endothelial cell and VSMC. Overall, decrease in a local endothelial stimulant, HGF, by high D-glucose may be a trigger of endothelial injury in diabetes, potentially resulting in the progression of atherosclerosis.

Topics: Animals; Aorta; Arteriosclerosis; Cell Division; Cells, Cultured; CHO Cells; Cricetinae; Culture Media, Conditioned; Diabetic Angiopathies; Endothelium, Vascular; Glucose; Hepatocyte Growth Factor; Humans; Mannitol; Muscle, Smooth, Vascular; Recombinant Proteins; Transforming Growth Factor beta

The distribution of atherosclerotic arterial disease in diabetes mellitus characteristically involves the infragenicular arterial tree including the anterior tibial, posterior tibial, and peroneal arteries. The proliferation of vascular smooth muscle cell (VSMC) is essential in the development of the atherosclerotic lesion. It has long been held that insulin plays a causative role in the formation of the atherosclerotic lesion in diabetes. We studied the role played by insulin in the proliferation of these cells in culture and the interaction of insulin with transforming growth factor beta 1 (TGF beta 1), a factor known for its possible inhibitory effects.. We have grown and characterized a line of VSMC harvested from atherosclerotic infragenicular arteries of human subjects undergoing below-knee amputation. The cultures were defined as being of VSMC origin by immunohistochemical staining with alpha-smooth muscle actin. Confluent cultures of passages 4 through 7 were seeded into six well plates at a density of 5000 cells/well. After serum deprivation the cells were exposed to insulin (100 ng/ml) alone or in combination with TGF beta 1 (6 ng/ml).. Our findings indicate that a 48-hour incubation with insulin augments the proliferation of human infragenicular VSMC, producing a 207% increase in cell number when compared with control cells (11,328 +/- 686, n = 56 vs 3682 +/- 182, n = 87; p < 0.0001). The addition of TGF beta 1 in combination with insulin abolished the accelerated growth rate seen in test groups treated with insulin alone (3614 +/- 247, n = 32 vs 11,328 +/- 686, n = 56; p < 0.0001).. These results strongly suggest that insulin is a potent stimulant of human infragenicular VSMC proliferation. The mitogenic effect of insulin is inhibited by TGF beta 1, producing proliferation rates comparable to those observed in control cells incubated with serum-free media.

Topics: Actins; Arteriosclerosis; Cell Count; Cell Division; Cell Line; Diabetic Angiopathies; Dose-Response Relationship, Drug; Humans; Immunohistochemistry; Insulin; Leg; Muscle, Smooth, Vascular; 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