The Expression And Ubiquitin-dependent Degradation Of Ski Protein In Renal Interstitial Fibrosis And The Intervention Of Silybin

Objective:1.To observed expression of Ski in renal tissue of interstitial fibrosis,explored the role of Ski in renal interstitial fibrosis,and ubiquitinated degradation of Ski by Arkadia.2.To investigate the effect of silybin in the process of renal interstitial fibrosis and discuss its mechanism.Methods: 36 normal male Sprague-Dawley rats were divided into 3 groups randomly,sham opration group(S group),unilateral ureteral obstruction(UUO)model group(U group),Silybin(200mg/kg)therapy group(D group).The rates in U group and D group were ligatured left ureter,turning into tubulointerstitial fibrosis models.Six rats of each group were killed at the 7th day randomly,others were killed at the 14 th day.HE staining and Masson staining were used to observe the change of the renal pathological.The expressionof Ski,TGF-β1,E-cadherin,α-SMA,Smad3,FNandCol-Ⅲ by immunohistochemistry.Western Blot was used to examine the expression of Ski,Arkadia,TGF-β1,E-cadherin,α-SMA,Smad3,FN and Col-Ⅲ.The qRT-PCR were used to examine the expression of Ski,TGF-β1,Arkadia.Results: Compared with S group,the expression of Ski and E-cadherin decreased in the U group,while the expression of TGF-β1,E-cadherin,α-SMA,Smad3,FN,col-III,and Arkadia increased in time-depended manner(P<0.05).Compared with the U group,The expressions of Ski and E-cadherin proteins were significantly up-regulated in D group,while the expression of TGF-β1,α-SMA,Smad3,FN,col-III,and Arkadia were down-regulated in time-depended manner(P<0.05).The results of qRT-PCR showed that The expression of Ski mRNA in the model group was opposite to that in the protein expression,and the expression was increased,and the expression was decreased in the treatment group.The mRNA expression of TGF-β1 and Arkadia were consistent with that of protein expression,but silybin was not statistically different from Arkadia.Silybin has no effect on the expression of Arkadia.Conclusion: 1.Ski possibly prevent renal interstitial fibrosis by the inhibition of TGF-β/smad signaling pathway.2.The mechanism of reduction of Ski protein may be related to its ubiquitin-dependent degradation in renal interstitial fibrosis.3.Silybin possibly delay the progression of renal interstitial fibrosis by up-regulating Ski and inhibition of TGFβ/samds signaling pathway.