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)

The possibility that tumor necrosis factor (TNF) and interleukin-1 (IL-1) could participate in the development of diabetic nephropathy was evaluated in streptozocin (STZ)-treated diabetic rats. Diabetic rats were divided into two groups: aminoguanidine treated group (25 mg/kg body wt, daily i.p. injection; DM-AG group) and untreated group (DM group). Non-diabetic age-matched rats were also divided into two groups with the same manner and used as controls. After twelve weeks of treatment, glomerular basement membranes (GBM) were isolated from rats of each experimental group. When thioglycollate-elicited peritoneal macrophages (M phi) from normal rats were incubated with these GBM materials, GBM from DM group induced significantly greater levels of TNF and IL-1 production than did GBM from other three groups with at doses of 2.5 to 10 mg. The TNF and IL-1 production by stimulation of GBM from the DM-AG group were similar to those from each control group. Aminoguanidine treatment significantly decreased the accumulation of advanced glycation end-products (AGEs) in GBM of diabetic rats. These findings suggest that AGE-proteins may be involved in the production of TNF and IL-1 from M phi. AGE-induced cytokines may be implicated in the development of diabetic nephropathy.
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PMID:Possible role of tumor necrosis factor and interleukin-1 in the development of diabetic nephropathy. 176 1

We have previously reported that the mRNA levels of endothelin (ET-1), tumor necrosis factor-alpha), (TNF-alpha), platelet-derived growth factor (PDGF)-B chain, transforming growth factor (TGF-beta), and basic fibroblast growth factor (bFGF) all increased with age in diabetic rat glomeruli. We have now assessed the effect of the angiotensin-converting enzyme inhibitor enalapril on the expression of the ET-1, TNF-alpha, PDGF-B, TGF-beta, and bFGF genes in 24-week-old rat glomeruli after streptozotocin injection. Animals were divided into controls, enalapril-treated diabetic rats, and untreated diabetic rats. Treatment continued for 24 weeks. Enalapril reduced both creatinine clearance (p < 0.001) and urinary protein excretion (p < 0.01) in diabetic rats. Enalapril produced a nonsignificant 15 mm Hg reduction in blood pressure in diabetic rats. Enalapril also attenuated the increases in ET-1 mRNA levels observed in the glomeruli of diabetic rats (0.5-fold compared with untreated diabetic rats at 24 weeks [p < 0.01]) but had no effect on increased mRNA levels of TNF-alpha, PDGF-B, TGF-beta, and bFGF. These findings suggest that enalapril therapy may be effective in reducing ET-1 mRNA expression in the glomeruli of diabetic nephropathy.
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PMID:Effects of enalapril on endothelin-1 and growth factor gene expression in diabetic rat glomeruli. 819 82

Hypertension, diabetes mellitus and chronic glomerular diseases reportedly cause in excess of 80% of the incident cases of end-stage renal disease (ESRD) in the U.S. The factors that initiate progressive renal failure in patients with these disorders remain unknown. Several investigators have reported enhanced synthesis and activity of cytokines in the kidneys of patients with renal failure. The ensuing inflammation and fibrosis have been postulated to contribute to the development of progressive renal failure. There is also abundant evidence supporting the contribution of genetic factors in ESRD susceptibility based upon the strong familial clustering of ESRD, particularly in African Americans. Therefore, genetic linkage analysis may be useful to evaluate the role of candidate genes in several cytokine cascades that could contribute to the pathogenesis of chronic renal failure. We tested for genetic linkage between eight cytokine candidate genes and chronic renal failure in a collection of African American sibling pairs concordant for ESRD. Epidermal growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF) beta 1, TGF-beta 2 and TGF-beta 3, and tumor necrosis factor (TNF)-alpha and TNF-beta candidate genes were selected for analysis due to their putative roles in diabetic renal disease and chronic glomerulonephritis. The interleukin-1 receptor antagonist gene (IL1RN) was also genotyped due to its reported association with diabetic nephropathy. Non-parametric (genetic model independent) affected sib pair linkage analysis was used to evaluate evidence for linkage. In order to genotype TGF-beta 3, we identified four closely linked, previously unidentified, highly polymorphic microsatellite loci near the TGF-beta 3 gene. Linkage of ESRD and transforming growth factor beta 2 polymorphisms on human chromosome 1 approached significance for non-diabetic nephropathy (predominantly chronic glomerular disease, hypertensive nephrosclerosis and unknown etiology) (P = 0.08), but showed no linkage to diabetic nephropathy. The other candidate loci did not demonstrate linkage to ESRD in the total population or in the subgroups with diabetic or non-diabetic etiologies of ESRD. The IL1RN gene did not show significant evidence for linkage to ESRD; however, we did confirm an association between allele 2 of IL1RN and ESRD (as reported in diabetic nephropathy). Overall, these results suggest that these growth factor loci do not make major contributions to the pathogenesis of ESRD in African Americans.
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PMID:Genetic linkage analysis of growth factor loci and end-stage renal disease in African Americans. 906 16

In order to investigate the status of some circulating factors in nephrotic syndrome, we examined the secretion of monocyte chemotactic peptide (MCP)-1, tumor necrosis factor (TNF) alpha or fibronectin in sera or by peripheral blood mononuclear cells (PBMC) from patients with membranous nephropathy (MN), diabetic nephropathy (DN) or minimal change disease (MCD). Also the effects of PBMC or sera on human mesangial cells (MC) were evaluated. Serum TNF alpha levels were higher in patients with MN than in controls, but PBMC exhibited no differences in TNF alpha production between patients and controls. Serum fibronectin levels were higher in patients with MN than in controls. PBMC from diabetic patients with or without nephropathy produced more MCP-1 than cells from controls. When MC were cultured with PBMC supernatants from patients, TNF alpha levels in PBMC supernatants correlated with production of MCP-1 or fibronectin by MC. PBMC supernatants obtained from patients with MCD and MN decreased MCP-1 production by MC, but did not affect thymidine incorporation or fibronectin production by MC. Sera obtained from patients with DN and MCD reduced thymidine incorporation in MC. In summary, serum TNF alpha or fibronectin levels were increased in patients with MN that is known to progress to renal failure. MCP-1 Production was increased by PBMC obtained from diabetic patients with or without nephropathy. Also TNF alpha production by PBMC in individual patients may affect the pathophysiology of their MC.
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PMID:Circulating factors in sera or peripheral blood mononuclear cells in patients with membranous nephropathy or diabetic nephropathy. 944 93

In 24 diabetic patients with advanced renal failure (creatinine clearance [C(Cr)] < 35 mL/min), we prospectively studied serum tumor necrosis factor-alpha (TNF-alpha) levels, the possible relationship with urinary protein excretion, and the effects of pentoxifylline (PTF) administration. PTF (400 mg daily) was administered for 6 months to 14 patients, and the results were compared with data from a control group (n = 10). Baseline parameters were similar in both groups. At the end of the study, urinary protein excretion and serum TNF-alpha decreased in the active group from 2.7 (1.2 to 5.8) g/d and 569 +/- 285 pg/mL to 1.1 (0.3 to 4.0) g/d and 329 +/- 232 pg/mL, respectively (P < 0.001). By contrast, proteinuria and TNF-alpha did not change in the control group. Regression analysis showed a significant correlation between proteinuria and serum TNF-alpha both at basal (r = 0.55) and at the sixth month (r = 0.57). Furthermore, the reduction of urinary protein excretion was strongly correlated with the decrease of TNF-alpha (r = 0.72, P < 0.01). Serum Cr and C(Cr) remained stable in both groups during the study. Our findings suggest that cytokines might play a role in renal damage in diabetic nephropathy. PTF is effective in reducing proteinuria in diabetic patients with advanced renal failure. The anticytokine activity of PTF may be a further explanation for this antiproteinuric effect.
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PMID:Urinary protein excretion and serum tumor necrosis factor in diabetic patients with advanced renal failure: effects of pentoxifylline administration. 1007 Sep 9

Intraglomerular hypertension is a primary causal factor in the progressive glomerulosclerosis that characterizes diabetic nephropathy or severe renal ablation. However, inflammation of the glomerular mesangium also participates in at least the early phase of these diseases. In glomerulonephritis, where inflammation is thought to be the predominant causal factor, intraglomerular hypertension is also often present. Mesangial cells (MCs) are critical in orchestrating key functions of the glomerulus including extracellular matrix metabolism, cytokine production, and interaction with leukocytes. Because MCs are subject to increased stretching when intraglomerular hypertension is present, and in glomerulonephritis MC/leukocyte interactions seem to be mediated primarily via the up-regulation of intercellular adhesion molecule-1 (ICAM-1), we examine the possibility that cyclic stretching is a stimulus for increased MC ICAM-1 activity. We demonstrate that the normal low levels of MC ICAM-1 mRNA and protein are dramatically up-regulated by even short intervals of cyclic stretch. This effect is dose- and time-dependent, and requires little amplitude and a brief period of elongation for significant induction. Stretch-induced MC ICAM-1 also leads to a marked elevation in phagocytic leukocyte adherence. This stimulated adherence is equal or greater than that induced by the inflammatory cytokine tumor necrosis factor-alpha, whereas an additive effect occurs when both are applied in combination. Our results indicate that stretch-induced ICAM-1 may provide a direct link between hypertension and inflammation in the progression of injury and glomerulosclerosis in diabetes, renal ablation, and other forms of glomerulonephritis.
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PMID:Cyclic stretching of mesangial cells up-regulates intercellular adhesion molecule-1 and leukocyte adherence: a possible new mechanism for glomerulosclerosis. 1114 73

In experimental and human diabetic nephropathy (DN), it has been shown that advanced glycation end products (AGEs), in particular, carboxymethyl-lysine and pentosidine, accumulate with malondialdehyde in glomerular lesions in relation to disease severity and in the presence of an upregulated receptor for AGE (RAGE) in podocytes. Toxic effects of AGEs result from structural and functional alterations in plasma and extracellular matrix (ECM) proteins, in particular, from cross-linking of proteins and interaction of AGEs with their receptors and/or binding proteins. In mesangial and endothelial cells, the AGE-RAGE interaction caused enhanced formation of oxygen radicals with subsequent activation of nuclear factor-kappaB and release of pro-inflammatory cytokines (interleukin-6, tumor necrosis factor-alpha), growth factors (transforming growth factor-beta1 [TGF-beta1], insulin-like growth factor-1), and adhesion molecules (vascular cell adhesion molecule-1, intercellular adhesion molecule-1). In tubular cells, incubation with AGE albumin was followed by stimulation of the mitogen-activating protein (MAP) kinase pathway and its downstream target, the activating protien-1 (AP-1) complex, TGF-beta1 overexpression, enhanced protein kinase C activity, decreased cell proliferation, and impaired protein degradation rate, in part caused by decreased cathepsin activities. The pathogenic relevance of AGEs was further verified by in vivo experiments in euglycemic rats and mice by the parenteral administration of AGE albumin, leading in the glomeruli to TGF-beta1 overproduction, enhanced gene expression of ECM proteins, and morphological lesions similar to those of DN. Evidence for the pathogenic relevance of AGEs in DN also comes from experimental studies in which the formation and/or action of AGEs was modulated by aminoguanidine, OPB-9195, pyridoxamine, soluble RAGEs, serine protease trypsin, and antioxidants, resulting in improved cell and/or renal function.
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PMID:Advanced glycation end products and the progressive course of renal disease. 1157 32

To compare levels of interleukin (IL)-18, tumor necrosis factor-alpha (TNF-alpha), and IL-6 in serum, we studied 151 type 2 diabetes mellitus patients with various degrees of nephropathy, as well as 80 healthy volunteers. IL-18, TNF-alpha, and IL-6 in serum were measured using an enzyme-linked immunosorbent assay (ELISA) with the respective mouse monoclonal antibodies. Significant differences in serum levels of IL-18 and TNF-alpha were observed between the patients and control subjects (IL-18, 278.0 +/- 11.9 pg/mL v 172.8 +/- 7.7 pg/mL, P <.0001; TNF-alpha, 2.41 +/- 0.18 pg/mL v 0.46 +/- 0.18 pg/mL, P <.0001), whereas that of IL-6 was not different between the two groups (0.73 +/- 0.10 pg/mL v 0.65 +/- 0.08 pg/mL, difference not significant [NS]), although patients with nephropathy showed higher levels. In addition, IL-18 levels were increased in diabetic patients with the development of urinary albumin excretion, with the highest found in those with microalbuminuria (<30 micro g/mg creatinine, 252.7 +/- 16.4 pg/mL; 30 to >300 micro g/mg creatinine, 352.7 +/- 35.2 pg/mL; >>300 micro g/mg creatinine, 350.0 +/- 16.0 pg/mL). Similarly, TNF-alpha and IL-6 in diabetic patients with microalbuminuria or clinical albuminuria were significantly increased as compared with those without albuminuria (TNF-alpha, 3.20 +/- 0.41 pg/mL v 1.94 +/- 0.18 pg/mL; IL-6, 1.64 +/- 1.11 pg/mL v 0.51 +/- 0.05 pg/mL, P <.05, respectively). These results suggest that serum levels of IL-18, TNF-alpha, and IL-6 may have some etiopathogenic roles in diabetic nephropathy.
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PMID:Elevated levels of interleukin-18 and tumor necrosis factor-alpha in serum of patients with type 2 diabetes mellitus: relationship with diabetic nephropathy. 1476 84

The role of inflammatory cytokines in the pathogenesis of diabetic nephropathy has been studied in streptozotocin-induced diabetic rats. Rat kidneys were examined by light and electron microscopy and kidney homogenates were also analyzed by Western blot and flow cytometry for the expression of markers of inflammation namely, CD4+ and CD8+ T cells, macrophages, MHC classes I and II, the proinflammatory cytokines tumor necrosis factor-alpha, interferon-gamma and nitric oxide (NO). Light and electron microscope examination revealed infiltration of mononuclear cells throughout the renal parenchyma, with the glomeruli being more severely affected especially at 8 months after disease induction. Western blot and flow cytometric analyses revealed the infiltrating cells to be CD4+ T cells, CD8+ T cells and macrophages. Western blot analyses also revealed increased expression of the proinflammatory and Th1 cytokines tumor necrosis factor-alpha, interferon-gamma as well as nitric oxide. Using flow cytometry, we have shown that the difference in expression of CD4+ T cells in control and diabetic kidneys is more significant at 1 month than at 8 months, while expression of CD8+ T cells is more significant at 8 months. We speculate therefore that diabetic nephropathy is probably initiated and driven by a Th1 process. CD8+ T cells, however, become more significant at later stages of the disease when tissue loss is evident. Since NO induction also occurs only after 8 months, we hypothesize that NO might be significant for the later stages of the disease. Our data implicate inflammation in the pathogenesis of diabetic nephropathy in view of the overexpression of the proinflammatory cytokines TNF-alpha and IFN-gamma and the cells that secrete them in the early and late phases of the disease.
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PMID:Streptozotocin-induced diabetic nephropathy in rats: the role of inflammatory cytokines. 1597 18

We examined the effect of PGE1 on the expression of plasminogen activator inhibitor-1 (PAI-1) mRNA induced by tumor necrosis factor-alpha (TNF-alpha) in human mesangial cells, because PAI-1 is one of major factors for the progression of glomerulosclerosis. The expression of PAI-1 mRNA was increased after stimulation with TNF-alpha, and it was diminished by pre-incubation with PGE1. Next, we examined the effect of PGE1 on the phosphorylation of mitogen activated protein kinase (MAPK) family and Akt. TNF-alpha activated the phosphorylation of p44/42 MAPK, p38 MAPK, SAPK/JNK and Akt in mesangial cells. PGE1 inhibited the TNF-alpha induced phosphorylation of SAPK/JNK and Akt, but not p44/42 MAPK and p38 MAPK. The TNF-alpha induced expression of PAI-1 mRNA was not affected by PD98059, an inhibitor of MEK, SB203580, an inhibitor of p38 MAPK, nor LY294002, an inhibitor of PI3 K. However, DMAP, an inhibitor of SAPK/JNK, inhibited the expression of PAI-1 mRNA, suggesting that the TNF-alpha induced expression of PAI-1 mRNA is regulated by the SAPK/JNK dependent pathway in human mesangial cells. By the incubation with H8, an inhibitor of PKA, the inhibitory effect of PGE1 on the expression of PAI-1 mRNA was abolished, suggesting that PGE1 inhibited the PAI-1 mRNA expression via the PKA pathway. Our results suggest that the inhibition of PAI-1 synthesis by PGE1 in human mesangial cells may have therapeutic implications for glomerulosclerosis such as occurs in diabetic nephropathy.
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PMID:PGE1 inhibits the expression of PAI-1 mRNA induced by TNF-alpha in human mesangial cells. 1602 96


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