上调miR-200c通过抑制TGF-β1/Smad3通路减轻单侧输尿管梗阻小鼠肾纤维化

Upregulation of miR-200c reduces unilateral ureteral obstruction-induced renal fibrosis in mice through inhibiting TGF-β1/Smad3 pathway

目的观察mi R-200c在单侧输尿管梗阻(unilateral ureteral obstruction,UUO)小鼠肾组织中的表达变化及其对UUO小鼠肾间质纤维化和TGF-β1/Smad3通路的影响。方法 45只C57BL/6J小鼠,随机数字表法分为假UUO组、UUO组、UUO+agomi R-200c组,每组15只。假UUO组仅游离左侧输尿管但不结扎;UUO组和UUO+agomi R-200c组通过结扎左侧输尿管建立的肾纤维化模型,手术后第1、7、14d两组小鼠分别给予生理盐水和agomir-200c尾静脉注射。第21d后处死全部小鼠,取血测定血肌酐(Scr)、血尿素氮(BUN)。取小鼠梗阻侧肾脏组织,HE染色和Masson染色评价肾小管间质损伤和肾间质纤维化损伤程度,实时荧光定量PCR(q RT-PCR)检测肾组织mi R-200c的表达,Western blotting检测肾组织TGF-β1、Smad3及α平滑肌肌动蛋白(α-SMA)蛋白的表达。结果与假UUO组比较,UUO组小鼠肾组织mi R-200c的表达水平明显降低,血清Scr、BUN水平明显升高,肾小管间质损伤病理评分升高,肾胶原容积分数(c VF)增加,肾组织中TGF-β1、Smad3及α-SMA水平明显升高。与UUO组比较,UUO+agomi R-200c组小鼠肾组织mi R-200c的表达明显增高,血清Scr、BUN水平明显降低,肾小管间质损伤病理评分下降,肾胶原容积分数减少,肾组织中TGF-β1、Smad3及α-SMA水平明显降低。结论上调mi R-200c能够通过抑制TGF-β1/Smad3通路减轻UUO小鼠肾间质纤维化。

Objective To investigate the effects of miR-200c expression level on renal interstitial fibrosis and transforming growth factor betal(TGF-pl)/Smad3 pathway in unilateral ureteral obstruction(UUO)mice.Methods Forty-five C57BL/6J mice were randomly divided into sham UUO,UUO,UUO+agomiR-200c with 15 rats in each group.Renal fibrosis model was established in UUO and UUO+agomiR-200c groups through ligation of the le ft ureter,w hile in sham UUO group the left ureter was dissociated w ith no ligation.On the 1st,7th,and 14th day after surgery,the mice in UUO and UUO+agomir-200c group were given saline or agomir-200c tailvein injection respectively.A ll rats were sacrificed 21 days later.Blood samples were collected to determine serum creatinine(Scr)and blood urea nitrogen(BUN).Renal tissues in the obstruction side were taken for HE staining and Masson staining to evaluate the degree of tubulointerstitial injury and renal interstitial fibrosis.Furthermore,miR-200c expression in renal tissues was detected using real-time fluorescence quantitative PCR(qRT-PCR),w hile the expression of TG F-pi,Smad3 and a-smooth muscle actin(a-SM A)were detected by Western blotting.Results Compared w ith the sham UUO group,the decrease of miR-200c and the increase of TG F-pl,Smad3 and a-SMA expression were statistically significant in UUO group.In addition,Scr and BUN levels were remarkably increased so as the pathological score of renal tubulointerstitial injury and the renal collagen volume fraction(cVF).Compared w ith UUO group,agomiR-200c treatment was able to reverse the above changes to different degrees.Conclusion Up-regulation of miR-200c can reduce the renal interstitial fibrosis in UUO mice by inhibiting the TGF-pl/Smad3 pathway.