Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011881 (diabetic nephropathy)
 10,836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vascular endothelial growth factor (VEGF) is a dimeric glycoprotein that exerts a proliferative effect specifically on endothelial cells. VEGF can increase vascular permeability and collagenase activity, is chemotactic for monocytes, and may dilate blood vessels. It can be induced by phorbol ester and cAMP in both mesenchymal and epithelial cells. In vitro cell culture experiments suggest that VEGF is upregulated by oxygen deprivation. In this study we tested whether in vivo acute and/or chronic reduction of renal blood flow by vascular obstruction would result in increased expression of VEGF mRNA and protein. Three normal kidneys, five human kidneys with narrowing of preglomerular vessels by vascular rejection or by vasculitis, and eight kidneys with nephrosclerosis and/or diabetic nephropathy were examined. In situ hybridization with 35S-labelled riboprobes showed a pronounced expression of VEGF mRNA in acutely hypoxic proximal and distal tubules of both the cortex and medulla; VEGF protein was demonstrated in the epithelia of these tubules by immunohistochemistry. In kidneys with chronically reduced blood flow, the majority of atrophic tubules were negative for VEGF mRNA and protein, although interstitial cells expressed VEGF mRNA. In arcuate arteries showing intimal and adventitial fibrosis, some medial smooth muscle cells were positive for VEGF mRNA. In glomeruli with segmental sclerosis, viable podocytes showed a prominent signal for VEGF mRNA. Mesangial cells did not express VEGF in the cases studied. It is possible that hypoxia itself led to the upregulation of VEGF in tubular epithelia and vascular smooth muscle cells. The vasodilatory and permeability-promoting effects of the endothelial growth factor produced by damaged tubular epithelia may constitute a mechanism to alleviate a decrease in blood flow and substrate availability and to re-establish vascular integrity.
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PMID:Expression of vascular endothelial growth factor in renal vascular disease and renal allografts. 855 88

Vascular endothelial growth factor (VEGF) stimulates nitric oxide (NO) production by endothelial cells in vitro and in vivo. However, the impact of VEGF on inducible nitric oxide synthase (iNOS) activity and NO synthesis in cultured mesangial cells is not known. Therefore, we measured nitrite accumulation in cytokine-stimulated, rat mesangial cells (RMC) in response to graded concentrations of VEGF. Addition of VEGF (10-50 ng/ml) did not alter RMC viability or NO production in either normal (5.6 mM) or high (33.3 mM) glucose conditions. Exposure of RMC to VEGF did not modify the effects of L-arginine (20 mM) or L-NAME (1 mM) on nitrite accumulation in normal or high glucose media. The steady state abundance of iNOS mRNA and the cytosolic content of iNOS protein were unaffected by addition of VEGF. Cultured RMC expressed the high-affinity tyrosine kinase VEGF receptors, flt and flk/KDR, and the levels were not modulated by incubation in normal or high glucose media. We conclude that VEGF does not regulate proliferation or NO production in cultured RMC. These findings suggest that disturbances in the normal interaction between VEGF and NO are not involved in the pathogenesis of abnormal mesangial cell structure or function in diabetic nephropathy.
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PMID:Effect of vascular endothelial growth factor on nitric oxide production by cultured rat mesangial cells. 957 Nov 72

The morphologic alterations in the kidney and the retina that can be present in patients with diabetic microangiopathy are mediated by growth factors. Vascular endothelial growth factor (VEGF) is a mediator of neoangiogenesis in diabetic retinopathy. Transforming growth factor-beta (TGF-beta) is involved in the extracellular matrix proliferation in diabetic nephropathy. The aim of the present study was to investigate the presence of VEGF and TGF-beta1 in peritoneal effluents of patients undergoing continuous ambulatory peritoneal dialysis who are being treated with glucose-containing dialysis solutions in relation to parameters of peritoneal transport. Standard peritoneal permeability analyses with 3.86% glucose dialysate were performed in 16 stable patients undergoing peritoneal dialysis (PD) (median duration of PD 39 months, range 1 to 104 months). The power relationship that is present between dialysate/serum (D/S) ratios of serum proteins that are transported only across the peritoneal membrane and their molecular weights was used to predict the D/S ratios when diffusion would be the only explanation for the measured dialysate concentration. It was assumed that all TGF-beta1 in the circulation was bound to alpha2-macroglobulin. The D/S ratios of VEGF (P < .0005) and TGF-beta1 (P < .015) were significantly higher than expected when VEGF and TGF-beta1 would have been transported from the circulation only by diffusion. No relationship was present between the effluent concentration attributed to the local production of VEGF (LVEGF) and that of TGF-beta1 (LTGF-beta1). LVEGF correlated with the mass transfer area coefficient (MTAC) creatinine value (r = 0.69, P < .007), MTAC urate value (r = 0.60, P < .02), and glucose absorption value (r = 0.75, P < .004), all reflections of the peritoneal vascular surface area. A negative correlation was observed between the transcapillary ultrafiltration (926 mL/4 h, 394 to 1262 mL/4 h) and LVEGF (r = -0.52, P < .045). This negative tendency was also observed between the net ultrafiltration (622 mL/4 h, -43 to 938 mL/4 h) and LVEGF (r = -0.48) but did not reach significance. LVEGF and the duration of treatment did not correlate, possibly because of the relatively small number of patients. LTGF-beta1 showed no relationship with transport parameters or duration of treatment. In conclusion, we found evidence for the local production of both VEGF and TGF-beta1 in the peritoneal membrane of patients undergoing long-term peritoneal dialysis with glucose-based dialysate solutions. The analogy with VEGF in diabetic retinopathy suggests a pathogenetic role of high dialysate glucose concentrations in the development of these alterations in the peritoneal membrane.
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PMID:Growth factors VEGF and TGF-beta1 in peritoneal dialysis. 1044 22

Diabetic nephropathy associated with hyperglycemia is characterized by glomerular hyperfiltration and endothelial dysfunction. Vascular endothelial growth factor (VEGF) is known to be primarily involved in neoangiogenesis and increased endothelial permeability. The purpose of this study was to investigate VEGF expression in response to high glucose in rat cultured mesangial cells and to identify its signal pathway via protein kinase C (PKC). Rat mesangial cells were cultured with different concentrations of glucose: normal (5 mM d-glucose), medium (15 mM d-glucose) and high (30 mm d-glucose). Calphostin-C as a PKC inhibitor and phorbol myristate acetate (PMA) as a PKC downregulator were instillated into culture media to evaluate the role of PKC in mediating the glucose-induced increase in VEGF expression. High glucose increased expression of VEGF at the mRNA and protein levels, identified by semi-quantitative RT-PCR and western blotting, within 3 h and in a time- and glucose concentration-dependent manner. Calphostin-C and PMA inhibited glucose-induced increases in VEGF expression at the mRNA and protein levels. In conclusion, high glucose can directly increase VEGF expression in rat mesangial cells via a PKC-dependent mechanism. These results suggest that VEGF could be a potential mediator of glomerular hyperfiltration and proteinuria in diabetic nephropathy.
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PMID:Expression of vascular endothelial growth factor in response to high glucose in rat mesangial cells. 1082 45

Vascular endothelial growth factor (VEGF) is a cytokine that potently stimulates angiogenesis, microvascular hyperpermeability, and endothelium-dependent vasodilation, effects that are largely mediated by endothelial nitric oxide synthase (eNOS). The expression of VEGF is pronounced in glomerular visceral epithelial cells, but its function in renal physiology and pathophysiology is unknown. VEGF expression is upregulated by high ambient glucose concentrations in several cell types in vitro and in glomeruli of diabetic rats. To assess the role of VEGF in the pathophysiology of early renal dysfunction in diabetes, monoclonal anti-VEGF antibodies (Ab) were administered to control and streptozotocin-induced diabetic rats for 6 wk after induction of diabetes. Based on in vitro binding studies, an adequate serum VEGF inhibitory activity was achieved during the entire course of anti-VEGF Ab administration. Anti-VEGF Ab treatment but not administration of isotype-matched control Ab decreased hyperfiltration, albuminuria, and glomerular hypertrophy in diabetic rats. VEGF blockade also prevented the upregulation of eNOS expression in glomerular capillary endothelial cells of diabetic rats. Antagonism of VEGF had no effect on GFR and glomerular volume in control rats. These results identify VEGF as a pathogenetic link between hyperglycemia and early renal dysfunction in diabetes. Targeting VEGF may prove useful as a therapeutic strategy for the treatment of early diabetic nephropathy.
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PMID:Antibodies against vascular endothelial growth factor improve early renal dysfunction in experimental diabetes. 1131 58

Vascular endothelial growth factor (VEGF) is involved in the pathogenesis of diabetic retinopathy but its role in diabetic nephropathy is only speculative so far. It has been shown that in renal cortex of normal kidneys, glomerular and tubular epithelial cells express VEGF and that VEGF 165 is the predominant isoform. Two VEGF receptors, KDR (kinase domain region) and Flt-1 (fms-like tyrosine kinase) are co-expressed by glomerular and peritubular capillary endothelial cells. However, VEGF and VEGF receptors are predominantly expressed at glomerular level. We recently demonstrated that in type 2 diabetic patients glomerular qualitative and quantitative changes of VEGF mRNA expression are associated with functional and structural renal changes. In the present work we focused on the tubulo-interstitial compartment; by reverse transcription/polymerase chain reaction (RT/PCR) we evaluated the expression of VEGF, KDR, Flt-1 and the relationship between the two main type of VEGF isoforms, VEGF121 and VEGF165 in the tubulo-interstitium of type 2 diabetic patients. Patients were divided in three category on the basis of renal structure pattern: CI, with normal or near normal renal structure; CII, with glomerular and tubulo-interstitial lesions occurring in parallel (typical diabetic nephropathology); CIII, with atypical pattern of renal injury, i.e., more severe tubulo-interstitial and vascular than glomerular changes. Comparison between the two cortical compartments revealed that, both in glomeruli and in tubulo-interstitium. VEGF121 isoform exceed VEGF165 while Flt-1 was significantly lower in glomeruli. CIII patients had the lowest tubulo-interstitial level of VEGF and Flt-1 mRNAs. These results suggest that the transcriptional shifting from VEGF165 to VEGF121 isoform and the unbalanced FIt-1 expression between tubulo-interstitium and glomeruli could be involved in the pathogenesis of diabetic nephropathy. Furthermore, at least in CIII patients, down-regulation of the VEGF-Flt-1 system could be involved in the mechanisms leading to tubulointerstitial diabetic lesions.
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PMID:Vascular endothelial growth factor (VEGF) and VEGF receptors in diabetic nephropathy: expression studies in biopsies of type 2 diabetic patients. 1149 63

This study was designed to evaluate whether vascular endothelial growth factor serum concentrations may identify adolescents with onset of type 1 diabetes during childhood at greater risk to develop persistent microalbuminuria and incipient diabetic nephropathy. In January 1989, vascular endothelial growth factor serum levels were measured in 101 normoalbuminuric diabetic children and adolescents (aged 7-14.9 yr; onset of diabetes before age 18 yr; duration of diabetes >7 yr). Participants were clinically examined at baseline and annually thereafter. Vascular endothelial growth factor serum concentrations were measured every year during the 8-yr follow-up period. Over 8 yr, 11 of 101 patients (10.9%) developed persistent microalbuminuria; no patient developed overt nephropathy. The risk of developing microalbuminuria was higher in children with increased vascular endothelial growth factor serum levels (using 160 pg/ml as the arbitrary cut-off point; group 1) compared with those with normal vascular endothelial growth factor serum levels at the beginning of the study (group 2; 19.2 vs. 2.0%; P < 0.01; sensitivity, 90.9%; specificity, 53.3%). The odds ratio for the occurrence of microalbuminuria after adjustment for confounding variables (albumin excretion rate, sex, hemoglobin A(1c), mean blood pressure, cholesterol, and triglycerides) in type 1 diabetic adolescents with elevated vascular endothelial growth factor serum levels was 4.1 (95% confidence interval, 2.0-10.9). These results suggest that vascular endothelial growth factor serum concentrations may be one of the predictors and risk factors for microalbuminuria and incipient diabetic nephropathy in adolescents and young adults with onset of diabetes during childhood. Persistently increased vascular endothelial growth factor serum levels may help to identify normotensive, normoalbuminuric patients with type 1 diabetes who are predisposed to develop persistent microalbuminuria later in life.
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PMID:Increased vascular endothelial growth factor serum concentrations may help to identify patients with onset of type 1 diabetes during childhood at risk for developing persistent microalbuminuria. 1150 26

Vascular endothelial growth factor, VEGF, is essential for endothelial cell differentiation (vasculogenesis) and for the sprouting of new capillaries from preexisting vessels (angiogenesis). In addition, there is strong evidence that VEGF is a survival factor allowing the cells to survive and proliferate under conditions of extreme stress. Hypoxia is a key regulator of VEGF gene expression. Besides hypoxia, many cytokines, hormones and growth factors can up-regulate VEGF mRNA expression in various cell types. VEGF is present in the glomerulus of both the fetal and adult kidney. The VEGF produced by glomerular epithelial cell may be responsible for maintenance of the fenestrated phenotype of glomerular epithelial cells, thus facilitating the high rate of glomerular ultrafiltration. But there is little known about the role of VEGF in the tubule. VEGF is thought to be involved in many kinds of kidney diseases. Whereas VEGF has a beneficial role in the pathogenesis in some diseases, it does harmful action in others. Because VEGF is known to be associated with the pathogenesis of some diseases, such as diabetic nephropathy, renal tumor and polycystic kidney disease, the study about the role of VEGF is going to be a target for disease control. On the other hand, an attempt at enhancing the role of VEGF has to be made at diseases like several ARF models and experimental glomerulonephritis.
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PMID:Role of VEGF in kidney development, microvascular maintenance and pathophysiology of renal disease. 1287 42

Diabetic retinopathy and nephropathy cause significant morbidity in patients with diabetes. Vascular endothelial growth factor (VEGF) is a potent angiogenic and vascular permeability factor and is implicated in both of these diabetes complications. We previously reported transfection studies showing the VEGF -460 and VEGF +405 polymorphisms to increase basal VEGF promoter activity by 71% compared with the wild-type sequence. Therefore, we investigated the association of these VEGF polymorphisms with proliferative diabetic retinopathy and diabetic nephropathy. DNA was isolated from 267 U.K. Caucasians with diabetes, comprising 69 patients with proliferative retinopathy and 198 patients with other grades of retinopathy. The distribution of VEGF -460 genotype was significantly different between the proliferative retinopathy and nonproliferative retinopathy groups (P = 0.027); specifically, carriage of the VEGF -460C allele was associated with proliferative diabetic retinopathy (odds ratio 2.5 [95% CI 1.20-5.23]). The VEGF -460 genotype was predictive of retinopathy, even after controlling for blood pressure, glycemic control, duration of diabetes, and obesity (P = 0.02). The VEGF +405 genotype did not associate with proliferative retinopathy, and neither polymorphism was associated with diabetic nephropathy. The VEGF -460C polymorphism is a positive independent predictive factor for the development of proliferative diabetic retinopathy. Increased VEGF production from high-expressing haplotypes, including -460C, may promote neovascularization.
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PMID:Association of the VEGF gene with proliferative diabetic retinopathy but not proteinuria in diabetes. 1498 76

Vascular endothelial growth factor (VEGF) is considered to have a role in the pathogenesis of diabetic retinopathy. Recent experimental observations that anti-VEGF neutralizing antibody fully abolished the hyperfiltration and the increase in urinary albumin excretion suggested the contribution of VEGF to the development of diabetic nephropathy, as well. Here, we present a case of POEMS (Crow-Fukase) syndrome with Type 2 diabetes, which was associated with elevated plasma VEGF level, but no sign of diabetic nephropathy. The findings obtained from this case did not support the hypothesis that VEGF may enhance the development of diabetic nephropathy.
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PMID:No nephropathy in Type 2 diabetic patient with POEMS syndrome with an elevated plasma VEGF. 1500 43


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