慢病毒介导miR-181a-5p过表达对慢性心力衰竭大鼠心脏重塑的影响

Effect of lentivirus-mediated miR-181a-5p overexpression on cardiac remodeling in rats with chronic heart failure

目的探究慢病毒介导微RNA-181a-5p(miR-181a-5p)过表达对慢性心力衰竭(CHF)大鼠心脏重塑的影响。方法采用随机数字表法将40只大鼠随机分为对照组、模型组、空载体组和miR-181a-5p过表达组,每组各10只。模型组、空载体组和miR-181a-5p过表达组均给予5 mg/kg·d^(-1)异丙肾上腺素腹腔注射处理。空载体组和miR-181a-5p过表达组分别尾静脉注射空载体和miR-181a-5p腺病毒载体。采用超声心动图检查大鼠心脏结构及功能,HE染色及Masson染色观察心肌组织病理及胶原纤维变化,实时荧光定量PCR(RT-qPCR)法检测miR-181a-5p、转化生长因子-β1(TGF-β1)mRNA及Smad3 mRNA水平,蛋白质免疫印迹法检测TGF-β1及Smad3蛋白水平。结果(1)与模型组及空载体组比较,miR-181a-5p过表达组大鼠舒张末期左心室内径(LVIDd)、收缩末期左心室内径(LVIDs)和心室质量/体质量(VW/BW)水平均降低,射血分数(EF)、缩短分数(FS)水平均升高,差异均有统计学意义(P<0.05)。(2)模型组及空载体组心肌细胞排列不规则,且有炎性细胞浸润,胶原纤维明显增加;miR-181a-5p过表达组大鼠心肌细胞排列较整齐,炎性细胞浸润较模型组和空载体组轻,胶原纤维较模型组和空载体组明显降低。(3)与模型组及空载体组比较,miR-181a-5p过表达组TGF-β1 mRNA、Smad3 mRNA、TGF-β1及Smad3表达量降低,差异均有统计学意义(P<0.05)。结论miR-181a-5p过表达对CHF大鼠心肌组织有一定保护作用,其机制可能与调控TGF-β1/Smad3通路有关。

Objective To investigate the effect of lentivirus-mediated microRNA-181a-5p(miR-181a-5p)overexpression on cardiac remodeling in rats with chronic heart failure(CHF).Methods Forty rats were randomly divided into control group,model group,empty vector group and miR-181a-5p overexpression group by random number table method,10 rats in each group.The model group,empty vector group and miR-181a-5p overexpression group were given intraperitoneal injection of 5 mg/kg·d^(-1) isoproterenol.The empty vector group and the miR-181a-5p overexpression group were injected into the empty vector and the miR-181a-5p adenovirus vector,respectively.Cardiac structure and function were examined by echocardiography;myocardial histopathology and collagen fiber changes were observed by HE staining and Masson staining;miR-181a-5p,transforming growth factor-β1(TGF-β1)mRNA and Smad3 mRNA were detected by real-time quantitative PCR(RT-qPCR);western blotting method to detect TGF-β1 and Smad3 protein levels.Results(1)Compared with the model group and empty vector group,the levels of left ventricular internal diameter at end-diastole(LVIDd),left ventricular internal diameter at end-systole(LVIDs)and ventricular weight/body weight(VW/BW)in the miR-181a-5p overexpressing group were decreased,and the levels of ejection fraction(EF)and fractional shortening(FS)were increased,the difference was statistically significant(P<0.05).(2)The myocardial cells in the model group and empty vector group were irregularly arranged,and there were inflammatory cell infiltration and collagen fibers increased significantly.The myocardial cells in the miR-181a-5p overexpressing group were arranged neatly,and the inflammatory cell infiltration was lighter than that in the model group and the empty vector group.Collagen fibers were significantly lower than those in the model group and the empty vector group.(3)Compared with the model group and empty vector group,the expression levels of TGF-β1 mRNA,Smad3 mRNA,TGF-β1 and Smad3 in miR-181a-5p overexpression group were decreased,and the differences were statistically significant(P<0.05).Conclusion The overexpression of miR-181a-5p has a protective effect on myocardial tissue of CHF rats,and its mechanism may be related to the regulation of TGF-β1/Smad3 pathway.