Effect of Simvastatin on Expression of CTGF and β-catenin in Renal Tubulointerstitium of Rats with Diabetic Nephropathy

Objective:To investigate the effect of simvastatin on the expression of connective tissue growth factor(CTGF) andβ-catenin in the renal tubulointerstitium of rats with diabetic nephropathy.Methods:30 Wistar male rats were divided randomly into three groups:normal control group(N),DN control group(DN),in which diabetes was induced by streptozotocin(STZ) and simvastatin treatment group(DS),in which STZ-induced diabetes rats were treated with simvastatin.All the rats received daily gavages for 12 weeks.The following parameters were measured after 4weeks,8 weeks and 12 weeks in each groups respectively,blood glucose(Glu),body weight and the 24 h urinary protein.after 12 weeks serum creatinine(Scr),urea nitrogen(BUN) and triglyceride(TC) were measured.The renal pathological changes were detected under light microscope.The expression levels of CTGF and β-catenin in the renal tubulointerstitium were assessed by immunohistochemistry method.The expressions of CTGF mRNA and β-catenin mRNA in renal tissue were determined by Real-time quantitative PCR.Results:After 12w,Compared with model group,the 24 h urinary protein,Scr,BUN in the treated group were significantly reduced(P0.05),the expression levels of CTGF and β-catenin in the renal tubulointerstitium were decreased(P0.05).Furthermore,by Real-time quantitative PCR,compared with model group,the mRNA levers of CTGF and β-catenin were decreased markedly(P0.05) in the treated group.Conclusion:Simvastatin can decrease protein urinary,reduce the expression levels of CTGF and β-catenin,protective effect of renal function.These findings suggest that simvastatin intervenes CTGF and wnt/β-catenin signaling pathway,may be probably involved in delaying the tubulointerstitial fibrosis.