糖尿病大鼠肾组织中miR-21和SnoN表达的变化

目的探讨糖尿病(DM)大鼠肾组织中微小核糖核酸-21(miR-21)和核转录共抑制因子(SnoN)在肾纤维化过程中的表达变化及其可能机制。方法用链脲佐菌素复制DM大鼠模型,并设对照组(NC),每组n=8。10周后处死大鼠,观察肾组织形态变化;免疫组织化学染色、Western blot及RT-q PCR检测miR-21、SnoN、转化生长因子-β1(TGF-β1)、Smad3、p-Smad3(Ser423/425)、E钙黏蛋白(E-cadherin)、α-平滑肌肌动蛋白(α-SMA)、纤维连接蛋白(FN)、胶原蛋白Ⅰ(collagenⅠ)和胶原蛋白Ⅲ(collagenⅢ)的表达。结果与对照组相比,DM组肾组织p-Smad3(Ser423/425)、TGF-β1和α-SMA蛋白表达增加(P0.05),SnoN、E-cadherin蛋白表达减少(P0.05),但SnoN mRNA和miR-21表达明显上调(P0.05),并伴有collagenⅠ、collagenⅢ和FN在间质沉积增多。结论 TGF-β1可能上调miR-21表达,抑制SnoN翻译水平的表达,促进DN的纤维化病变。

Expressions of miR-21 and SnoN in kidney of diabetic rats

Objective To investigate the expression and possible mechanism of miR-21 and Ski-related novel protein N( SnoN) in the renal fibrosis diabetic process.Methods The animal model was established by tail-vein injection of Streptozotocin,and the other group were normal control ( NC) group.After 10 weeks, the rats were sacrificed to measure biochemical parameters and renal index , and to observe the changes of pathomorphology by HE staining as well.Meanwhile, immunohistochemistry and Western blot were employed to examine protein ex-pression of E-cadherin,α-smooth muscle actin(α-SMA), fibronectin(FN), collagen-Ⅰ(Col-Ⅰ), collagen-Ⅲ(Col-Ⅲ), transforming growth factor-β1(TGF-β1), Smad3, p-Smad3(Ser423/425) and SnoN in the renal tissue. In addition, the expression of SonN mRNA and miR-21 were detected by qPCR.Results In DM group,the ex-pressions of Col-Ⅰ, Col-Ⅲ and FN in renal interstitium were increased ( P <0.05 ) , TGF-β1 increased (P<0.05),while E-cadherin decreased(P<0.05).Compared with NC group, the expression of α-SMA,p-Smad3 (Ser423/425) protein increased in DM group(P<0.05),while the protein level of SnoN decreased but the level of SnoN mRNA increased ( P <0.05 ) .Moreover, the level of miR-21 markedly increased in DM group ( P <0.05 ) .Conclusions TGF-β1 may up-regulate the expression of miR-21 but restrain the translational expression of SnoN, aggravating fibrosis.