miR-30a在心肌梗死大鼠心肌纤维化中的作用机制及对心功能的影响  

Function of miR-30a in myocardial fibrosis and it's impact on cardiac function in rats with myocardial infarction

作　　者：陈立文[1] 朱琳琳[1] 季倩[1] 朱灏[1] 任怡稚 樊仲国 李小波[1] 高晓飞[1] 张瑶俊[1] 田乃亮[1] 

机构地区：[1]南京医科大学附属南京医院南京市第一医院心内科,江苏南京210006

出　　处：《基础医学与临床》2017年第1期80-86,共7页Basic and Clinical Medicine

摘　　要：目的探讨miR-30a在大鼠心肌梗死后对心肌纤维化的作用机制及对心功能的影响。方法构建携带大鼠miR-30a基因的载体,在HEK293细胞中包装病毒载体r AAV9-miR-30a及阴性对照r AAV9-miR-30a-NC,提取纯化后通过冠脉注射方法分别传导PBS缓冲液、r AAV9-miR-30-NC和r AAV9-miR-30a至大鼠心脏,再建立大鼠心肌梗死模型,分别设为PBS组、miR-30-NC组和miR-30a组,同时设立假手术组(sham组)。用心脏彩色多普勒超声检测心功能指标,包括短轴缩短率(FS)及左室射血分数(LVEF);Masson染色观察心肌胶原容积分数(CVF);免疫组化法检测Ⅰ、Ⅲ型胶原表达;实时荧光定量PCR(real-time PCR)检测心肌miR-30a及TGF-β1和CTGF mRNA表达;蛋白印迹法(Western blot)检测TGF-β1及CTGF蛋白的表达。结果 miR-30a组心功能较PBS组及miR-30-NC组显著改善(P<0.05)。miR-30a组的心肌CVF及Ⅰ、Ⅲ胶原表达水平、Ⅰ/Ⅲ型胶原比值较PBS组及miR-30-NC组显著降低(P<0.01);miR-30a组心肌TGF-β1 mRNA及蛋白表达水平与PBS组及miR-30-NC组比较显著下降(P<0.001);CTGF mRNA及蛋白表达水平较PBS组及miR-30-NC组显著降低(P<0.001)。结论 miR-30a过表达能下调心肌梗死后心肌TGF-β1、CTGF mRNA及蛋白水平,从而减少心肌胶原产生,抑制心肌纤维化,进而改善心功能。Objective To explore the potential role and function of miR-30 a in myocardial fibrosis after myocardial infarction（ MI）. Methods We constructed the AAV plasmid vector which carried the miR-30 a gene of rat. The recombinant plasmid was detected by gene sequencing,enzyme digestion and PCR. Virus was packaged into HEK293 cells and virus titer was determined after extraction and purification by PCR. PBS fluid,r AAV9-miR-30 a-NC and r AAV9-miR-30 a were transmited to rat hearts from PBS group,miR-30 a-NC group and miR-30 a group respectively through transcoronary infusion before anterior descending coronary artery ligation. Sham group was set up at the same time. After 4 weeks,heart function was monitored by serial echocardiography,including fractional shortening（ FS）,and left ventricular ejection fraction（ LVEF）. Masson staining was used to calculate collagen volume fraction（ CVF）. The expression of collagen Ⅰ and Ⅲ were detected by immunohistochemistry.The mRNA level of miR-30 a,TGF-β1 and CTGF were detected by real-time PCR. The protein level of TGF-β1and CTGF were detected by western blot analysis. Results The cardiac function of miR-30 a group was improved significantly compared with PBS group and miR-30 a-NC group（ P 〈0. 05）. The levels of CVF,collagen Ⅰ,Ⅲexpression and Collagen Ⅰ / Ⅲ ratio in miR-30 a group was significantly lower than PBS group and miR-30 a-NC group（ P 〈0. 01）. The mRNA and protein level of TGF-β1 and CTGF in miR-30 a group were reduced significantly than PBS group and miR-30 a-NC group（ P 〈0. 001）. Conclusions The overexpression of miR-30 a after MI may reduce the mRNA and protein level of TGF-β1 and CTGF,so as to suppress myocardial fibrosis and improve cardiac function.

关 键 词：miR-30a 心肌梗死 心肌纤维化 转化生长因子Β1 结缔组织生长因子 

分 类 号：R542.22[医药卫生—心血管疾病]