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)

Diabetic nephropathy is now the commonest cause of end stage renal disease and accounts for 30-40% of all patients requiring renal replacement therapy. Furthermore, the incidence of diabetic nephropathy continues to increase, in part due to the improved survival of type 2 diabetic patients as the cardiovascular mortality in this group declines (Ritz and Stefanski, 1996). Clinically incipient nephropathy is first manifest by the onset of persistent microalbuminuria, after which, overt diabetic nephropathy is heralded by the appearance of persistent proteinuria. Subsequently, there is a progressive decline in glomerular filtration rate (GFR) resulting, within 5 years, in end stage renal disease in 50% of patients (Hasslacher et al., 1989). The pathology of the renal lesions are similar in type I and II diabetes (Taft et al., 1994), although it has been suggested that there is more heterogeneity in type II diabetes (Chihara et al., 1986). Studies analysing structural-functional relationships have demonstrated that the development of proteinuria correlates with the degree of mesangial expansion (Mauer et al., 1984; White and Bilous, 2000). Although diabetic nephropathy was traditionally considered a primarily glomerular disease, it is now widely accepted that the rate of deterioration of function correlates best with the degree of renal tubulointerstitial fibrosis (Mauer et al., 1984, Bohle et al., 1991). This suggests that although in the majority of patients the primary event is a condition manifest by glomerular changes resulting in proteinuria, the long-term outcome is determined by events in the renal interstitium. With the increasing awareness of the importance of these pathological interstitial changes, interest has focused on the role of cells, such as the epithelial cells of the proximal tubule (PTC) or the interstitial myofibroblast, in the initiation of fibrosis. The aim of the present review is to analyse the available data supporting the role for the PTC in orchestrating renal interstitial fibrosis in diabetic nephropathy as a result of glucose-dependent alterations in PTC function. The potential for subsequent effects on PTC-fibroblast cross-talk will also be considered.
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PMID:Diabetic nephropathy: the central role of renal proximal tubular cells in tubulointerstitial injury. 1181 75

Administration of spironolactone provides a beneficial effect in various animal models of renal injury. In this study, we investigated whether spironolactone prevents the progression of diabetic nephropathy through reduction of connective tissue growth factor (CTGF) synthesis in type II diabetic rats. In addition, we evaluated the effect of aldosterone and spironolactone on CTGF and collagen production in cultured cells. Renal functional and morphologic changes were examined in Otsuka Long-Evans Tokushima Fatty rats with or without spironolactone treatment (20 mg/kg/day) for 8 months, as well as in non-diabetic age-matched Long-Evans Tokushima Otsuka rats. Spironolactone treatment did not induce any significant differences in body weight, kidney/body weight ratio, serum creatinine concentration, blood glucose levels, or systolic blood pressure. However, urinary protein and albumin excretion were significantly decreased in the spironolactone treatment group, which was associated with amelioration of glomerulosclerosis. In addition, renal CTGF, collagen synthesis demonstrated marked decreases in the spironolactone treatment group. In cultured MC and PTC, aldosterone induced significant increases in CTGF gene expression and protein synthesis associated with increased collagen synthesis, which was abolished by prior treatment with spironolactone. However, aldosterone treatment did not induce transforming growth factor (TGF)-beta1 overproduction, and inhibition of TGF-beta1 by neutralization of TGF-beta1 protein did not significantly prevent aldosterone-induced CTGF production. These results suggest that the antifibrotic effects of spironolactone may be mediated by CTGF through a TGF-beta1-independent pathway in this animal model of diabetic nephropathy.
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PMID:Spironolactone ameliorates renal injury and connective tissue growth factor expression in type II diabetic rats. 1672 84

In PTC, it is clear that TGF-beta1 synthesis may be controlled independently at the levels of transcription and translation. In the context of diabetic nephropathy glucose is a potent stimulus of TGF-beta1 promoter activity. The resultant transcript is however poorly translated such that stimulation of PTC with glucose does not increase de novo TGF-beta1 protein synthesis. Although diabetes is a "metabolic" disease, in the kidney, nephropathy is associated with an inflammatory cell infiltrate. For example using the GK rat model of type II diabetes, we have demonstrated that progressive renal disease is associated with a prominent macrophage influx. This led us to examine TGF-beta1 regulation when the effects of macrophage derived cytokines such as platelet derived growth factor and interleukin-1 are combined with exposure to elevated glucose concentrations. These studies have demonstrated that such cytokines specifically facilitate translation of glucose induced TGF-beta1 transcripts. In addition, direct interaction between monocyte-macrophage CD18 and PTC cell surface ICAM-1 stimulates TGF-beta1 synthesis. Recent data from numerous experimental systems have suggested that the extracellular matrix component hyaluronan (HA) may be involved in the regulation of the inflammatory process. We have now identified HA based structures synthesised on the surface of PTC, which act to prevent PTC-macrophage interaction through ICAM-1 thus preventing macrophage driven TGF-beta1 synthesis. Disease promoting cytokines such as IL-1beta down-regulate these structures whilst potential therapeutic agents such as BMP-7 increase their assembly, that HA may possess disease limiting activity.
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PMID:The role of proximal tubular cells in interstitial fibrosis: understanding TGF-beta1. 1747 23