The Protective Effect Of Roscovitine On Kidney Of Diabetic Nephropathy Mice

Objective: With the aging of China’s population and the changes in lifestyle,diabetes(diabetes mellitus,DM)has evolved from a rare disease into an epidemic.As one of the most common microvascular complications of diabetes,diabetic nephropathy(DN)is a serious threat to people’s health and an important cause of disability and mortality of diabetic patients.Renal interstitial fibrosis caused by tubular injury plays an important role in the progression of DN.The initial stage of DN tubular lesions is mainly characterized by thickening of the basement membrane of the renal tubular,increased numbers of tubular and tubular hypertrophy,while the advanced stage is characterized by atrophy of the renal tubular and interstitial fibrosis.The key pathological basis for the progression of chronic kidney disease is renal interstitial fibrosis,which is a better indicator of the degree of kidney damage than glomerulosclerosis.Therefore,it is of great significance to investigate the treatment of renal tubule interstitial fibrosis and delay the progression of interstitial fibrosis so as to improve the prognosis of DN patients.Roscovitine is a purine analogue that plays a role by inhibiting cyclin-dependent kinase activity.Roscovitine has been proved to have a variety of pharmacological effects,such as anti-inflammatory,anti-proliferative and anti-fibrosis.Roscovitine demonstrated significant antifibrosis effects by inhibiting the expression of collagen,fibronectin and connective tissue growth factor in fibroblasts.This study aims to observe the protective effect and mechanism of roscovitine on kidney of diabetic mouse model.Methods: The mouse model of type 1 diabetes was established by abdominal cavity injection of Streptozotocin(STZ)in CD1 mouse.Diabetic model was thought to be successfully established when the venous glucose level was more than >16.7mmol/L after 72 hours and maintained for 1 weeks with positive urine glucose.The control group(NC group)was intraperitoneally injected with citric acid buffer.The control group were During the experiment,the mice in each group were permitted to eat freely and were not given insulin or other oral hypoglycemic drugs.After all the DM mice were successfully modeled,the DM mice were randomly divided into 3 groups(n=5):(1)DM group(2)Roscovitine low dose treatment group(RL group,intraperitoneal injection of 20 mg/kg of Roscovitine dissolved in DMSO daily);(3)Roscovitine high-dose treatment group(RH group,intraperitoneal injection of 40 mg/kg Roscovitine dissolved in DMSO daily).The final concentration of DMSO in each group was < 1%.At the end of 16 weeks,the mice were sacrificed to collect samples of blood,urine and kidney tissues,and blood glucose(Glu),blood urea nitrogen(BUN),creatinine(Scr),urine protein(Alb)were detected by Hitachi 7170-A automatic biochemical analyzer.The ratio of kidney weight(mg)to body weight(g)was used as the Kidney index(Kidney Index,KI).The effect of Roscovitine on kidney of diabetic nephropathy mice was evaluated by electron microscopy,light microscopy,immunohistochemistry and Western blot.Results: Compared with NC group,the blood sugar of DM group mice is significantly increased,and the blood BUN,Scr and urine albumin are all increased.Compared with DM group,Roscovitine treatment can significantly improve the renal function of diabetic mice,and the blood Scr,BUN,urine albumin and blood glucose levels are significantly reduced(P < 0.05).The effect of roscovitine is not associated with the concentration.HE,PAS and transmission electron microscopy showed that in DM mice,glomerular basement membrane was significantly thickened,podocyte foot processes fused,and the number decreased.Roscovitine can significantly reduce glomerular lesions after treatment.Masson staining results showed that the renal interstitial fibrous tissue of DM group mice proliferated significantly.Roscovitine treatment could significantly reduce the level of renal interstitial fibrosis and reduce the expression level of type III and type IV collagen in DM mice.Compared with NC group,the expression level of α-SMA in DM group mice was significantly increased,while the expression of E-cadherin was significantly decreased.Roscovitine has a significant inhibitory effect on tubulointerstitial transdifferentiation after treatment,and reducing the α-SMA expression and increasing the E-cadherin expression,while significantly reducing TGF-β1 expression in renal tissue of DM mice.Conclusions:1.Roscovitine significantly reduced hyperglycemia and improved the glomeruli injury and renal function of diabetic mice.2.Roscovitine can significantly reduce the degree of renal interstitial fibrosis in diabetic mice,and its mechanism of action is related to the down-regulation of TGF-β1 signaling pathway.