MicroRNA-21在单侧输尿管梗阻大鼠间质纤维化肾脏组织中的表达及意义?

目的：观察 MicroRNA-21(miRNA-21)在单侧输尿管梗阻(UUO)大鼠肾脏组织中的表达,初步探讨其在转化生长因子-β1(TGF-β1)/Smad3致大鼠肾间质纤维化(RIF)信号通路中的机制。方法选择20只 SD 雄性大鼠,分为 UUO 组和假手术组(Sham 组),分别于建模后第3天、第7天各采集每组5只大鼠肾脏组织,应用实时荧光定量 PCR(Real-time qPCR)方法检测肾脏组织中 miRNA-21的表达变化,采用 Masson 染色、苏木素-伊红(HE)染色和免疫组织化学技术评价肾组织纤维化,使用免疫组织化学检测肾脏组织中 TGF-β1、Smad3、Ⅰ型胶原蛋白(Col-Ⅰ)和α平滑肌肌动蛋白(α-SMA)表达情况。结果建模后第3天和第7天 UUO 组肾脏组织中 miRNA-21与 Sham 组比较均升高(P <0.01),7 d UUO 组肾组织中 miRNA-21与3 d UUO 组相比升高(P <0.01)。建模后3、7 d UUO 组 Masson 染色纤维化评分、TGF-β1、Samd3、α-SMA 及 Col-Ⅰ蛋白阳性表达面积较 Sham 组升高(P <0.01),以上指标7 d UUO 组较3 d UUO 组比较表达增强(P <0.01)。UUO 组肾组织中 miRNA-21的表达与肾间质纤维化评分正相关(r=0.888,P <0.01)；肾组织 miRNA-21与 TGF-β1、Smad3、Col-Ⅰ、α-SMA 蛋白表达呈正相关(r =0.799、0.849、0.882、0.896,P <0.01)。结论UUO 大鼠肾组织中 miRNA-21在建模后表达上调,且间质纤维化程度越重表达越高,TGF-β1/Smad3信号通路可能是通过上调 miRNA-21从而介导大鼠肾间质纤维化。

Expression and significance of MicroRNA-21 in renal tubulointerstitial fibrosis tissues of UUO rats

Objective To observe the expression of MicroRNA-21(miRNA-21)in kidney tissue of unilateral ureteral obstruc-tion (UUO)rats and explore mechanisms of miRNA-21 involved in TGF-β1/Smad3 signaling pathway in renal interstitial fibrosis (RIF).Methods Totally 20 adult male SD rats were divided into UUO group and Sham operation group.The left ureter of rats in UUO group were ligated,and the rats in sham group were dissociated left ureter only,but not to be obstructed.The left kidney tis-sue was collected at the 3rd、7th days after surgery.Real-time quantitative PCR analysed the expression of miRNA-21.Masson stai-ning,HE staining and immunohislochemistry staining were used to evaluate the degree of RIF.The expression of transforming growth factor-β1(TGF-β1)、Smad3,α-smooth muscle actin (α-SMA)、and collagenⅠ(Col-Ⅰ)were examined by immunohislochemis-try staining.Results The expression of miRNA-21 in kidney tissue was higher at 3rd、7th days after surgery in UUO groups than that in Sham group(P <0.01).The expression in UUO group at 7th day was higher than 3rd day after surgery(P <0.01).The fi-brosis score,positive TGF-β1、Smad3、Col-Ⅰ、α-SMA area in UUO group were significantly higher than those of Sham group at 3rd、7th days (P <0.01),Which at 7th day were higher than 3rd day in UUO group(P <0.01).The expressions of miRNA-21 in kidney tissue was positive correlations with the fibrosis score(r=0.888,P <0.01).The expressions of miRNA-21 in kidney tissue was positive correlations with TGF-β1、Smad3、Col-Ⅰ、α-SMA(r=0.799,0.849,0.882,0.896,P <0.01).Conclusion The expres-sion of miRNA-21 was upregulated in UUO kidney tissue after model establishment.The RIF degree might be positive correlations with miRNA-21 expression,and TGF-β1/Smad3 signaling pathway positively regulate miRNA-21 to mediate rats RIF.