The Effect Of Tacrolimus On Kidney Podocyte Oxidative Stress In Rats With Type 2 Diabetic Mellitus

Objective: To observation the effect of FK506 on the oxidative stress of kidney podocyte in type 2 diabetic rats.Method: The models were established by feeding high sugar-fat diet(10% lard,20% sucrose,2.5% cholesterol,1% cholate,and 66.5% conventional feed)and combining with a low dose streptozotocin(STZ 30 mg /kg),which were randomly divided into the diabetic mellitus group(DM group),the tacrolimus treatment group(FK group,FK506 0.5 mg /kg·d),and the normal control group(NC group)was also established The usual parameters were measured before and after 8 weeks treatment with FK506;Pathological changes of Nephridial tissue were observed under a light microscope and an electron microscope;Expression of nephrin was determined by immunohistochemistry;Expression of NOX4 was detected using Western blot.Result: There were 30 model rats,21 were successfully established type 2 diabetes rats,the successful rate were 70%.(1)The asting blood glucose(FBG),systolic blood pressure(SBP),creatinine clearance rate(Ccr),total cholesterol(TG),triglyceride(TC),24 h urinary albumin excretion rate(UAER),and the renal hypertrophy index(KW/BW)in groups DM were significantly increased(P<0.05)compared with the group NC,and the UAER、KW/BW were decreased after treatment of FK506(P<0.05).There were no significant difference(P>0.05)for the serum creatinine(SCr),alanine transaminase(ALT),aspartate Aminotransferase(AST),and white blood cell(WBC)in groups.(2)There was no significant abnormal pathological changes of nephridial tissue in group NC under the light microscope.There was significantly increased glomerular volume,proliferative mesangial cells,broaden mesangial area and thicken basement membrane in group DM.The above histopathological changes of groups FK were less compared with group DM(P<0.05);(3)Under the electron microscope,Compared with the group NC,group DM showed a significantly disordered and fused podocytic-process,and the glomerular basement membrane thickness(GBMT)was thickened notably(P<0.05).The above lesions in groups FK were less compared with group DM(P<0.05);(4)The results of immunohistochemistry: The expression of Nephrin in group DM were significantly lower(P<0.05)compared with the group NC,and Nephrin expression was obviously recovered in group FK;(5)Western blot results showed a significantly increased expression of NOX4 in group DM compared with group NC(P<0.05);The above indicators in group FK were significantly lower compared with group DM(P<0.05).(6)The Pearson correlation analysis showed that the renal NOX4 /β-actin leve was negatively correlated with Nephrin expression intensity(r=﹣0.65,p<0.01).Conclusions: Tacrolimus can decrease the proteinuria of the rats with DKD,it may be through reducing the expression of NOX4,inhibit oxidative stress,reduce podocyte injury,thereby slowing the process of DKD.