IncRNA CASC7、miR-21、Wnt2b、Smad7在肾纤维化大鼠肾组织中的表达意义分析

Significance of IncRNA CASC7,miR-21,Wnt2b and Smad7 in renal tissues of rats with renal fibrosis

目的:探讨长链非编码(Inc)RNA CASC7、微小RNA-21(miR21)、Wnt2b、Smad7在肾纤维化大鼠肾组织中的表达意义.方法:选取35只雄性8周龄健康SD大鼠,随机分为对照组(n=10)与模型组(n=25),模型组大鼠单侧肾切除后腹腔单次注射链脲佐菌素(40 mg/kg)建立糖尿病肾病模型,模型组大鼠在建模成功后2w、8w时随机选取10只处死后取肾脏组织,进行HE、Masson染色观察肾组织病理及纤维化程度,并通过qRT-PCT检测大鼠肾脏组织中IncRNA CASC7、miR-21相对表达水平,Western blot法检测Wnt2b、Smad7、I型胶原(Col-I)、IV型胶原(Col-IV)及纤维连接蛋白(FN)蛋白表达,并分析IncRNA CASC7、miR-21及Wnt2b、SMAD7与肾组织纤维化程度以及Col-I、Col-IV、FN的相关性.结果:2w、8w时,模型组大鼠尿白蛋白、尿肌酐、UACR、肾体比、肾纤维化严重程度评分、CVF均高于对照组(P<0.05);8w尿白蛋白、尿肌酐、UACR、肾体比、肾纤维化严重程度评分、CVF均高于2w(P<0.05);2w时模型组大鼠表现出肾皮质管壁增厚、炎性细胞浸润和胶原沉积,8 w时模型组大鼠纤维化和胶原沉积加重.与对照组比较,模型组2w、8w时大鼠肾组织CASC7 mRNA水平降低,miR-21 mRNA水平升高(P<0.05),Wnt2b、Smad7、Col-I、Col-IV、FN蛋白表达升高(P<0.05),且8w时上述指标变化趋势更显著(P<0.05).CASC7表达与DN大鼠肾纤维化程度、Col-I、Col-IV、FN呈负相关(P<0.05),miR-21、Wnt2b、Smad7与DN大鼠纤维化程度、Col-I、Col-IV、FN呈正相关(P<0.05).结论:IncRNA CASC7、miR-21、Wnt2b、Smad7参与肾纤维化大鼠疾病进展过程,其表达水平与肾纤维化程度存在关系.

Objective To explore the expression significance of long non-coding(Inc)RNA CASC7,microRNA-21(miR21),Wnt2b and Smad7 in renal tissues of rats with renal fibrosis.Methods A total of 35 healthy male 8-week-old SD rats were randomly divided into control group(n=10)and model group(n=25).In model group,models of diabetic nephropathy were constructed by intraperitoneal injection of streptozotocin(40 mg/kg)after unilateral nephrectomy.At 2 and 8 weeks after successful modeling,10 rats in model groups were executed to collect renal tissues.The pathology and fibrosis of renal tissues were observed by HE and Masson staining.The relative expression levels of IncRNA CASC7 and miR-21 in renal tissues were detected by qRT-PCT.The expressions of Wnt2b,Smad7,type Ⅰ collagen(Col-I),type Ⅳ collagen(Col-Ⅳ)and fibronectin(FN)proteins were detected by Western blot.The correlation between IncRNA CASC7,miR-21,Wnt2b,SMAD7 and the severity of renal fibrosis,Col-Ⅰ,Col-Ⅳ,FN was analyzed.Results At 2 and 8 weeks after modeling,urinary albumin,urinary creatinine,UACR,renal-body ratio,score of renal fibrosis severity and CVF in model group were higher than those in control group(P<0.05),and which at 8 weeks after modeling were higher than those at 2 weeks(P<0.05).At 2 weeks after modeling,there was thickening of renal cortical walls,inflammatory cells infiltration and collagen deposition in model group,and there was aggravation of fibrosis and collagen deposition at 8 weeks after modeling.Compared with control group,level of CASC7 mRNA was decreased,level of miR-21 mRNA was increased(P<0.05),and expressions of Wnt2b,Smad7,Col-Ⅰ,Col-Ⅳ and FN proteins were increased in model group at 2 and 8 weeks after modeling(P<0.05).The change trends of the above indexes were more significant at 8w after modeling(P<0.05).The expression of CASC7 was negatively correlated with the severity of renal fibrosis,Col-Ⅰ,Col-Ⅳ and FN(P<0.05),while miR-21,Wnt2b and Smad7 were positively correlated with them(P<0.05).Conclusion IncRNA CASC7,miR-21,Wnt2b and Smad7 are involved in disease progression of rats with renal fibrosis,and their expression levels are related to the severity of renal fibrosis.