miR-122在急性心肌梗死大鼠中的表达及其作用机制  

Expression and mechanism of miR-122 in rats with acute myocardial infarction

作　　者：倪卫兵[1] 蔡娟[1] 葛芳清[2] NI Wei-bing;CAI Juan;GE Fang-qing(Department of Cardiology,Nantong Hospital of Traditional Chinese Medicine,Nantong,Jiangsu 226001,China;Radiology Department,Nantong Hospital of Traditional Chinese Medicine,Nantong,Jiangsu 226001, China)

机构地区：[1]南通市中医院心内科,江苏南通226001 [2]南通市中医院放射科,江苏南通226001

出　　处：《海南医学院学报》2020年第10期749-753,759,共6页Journal of Hainan Medical University

基　　金：南通市科技项目(HS2014068)。

摘　　要：目的:探究miR-122在急性心肌梗死(AMI)大鼠中的表达变化及其对心肌细胞凋亡的影响。方法:80只雄性SD大鼠随机分为Sham组、AMI组、空病毒组和病毒组,构建急性心肌梗死大鼠模型。采用超声心动图检测大鼠心功能指标;采用RT-PCR分析miR-122的mRNA相对表达水平;采用TUNEL染色检测大鼠心肌细胞凋亡水平;构建NC-shRNA和miR-122-shRNA稳定细胞系,采用荧光素酶报告基因验证miR-122和XIAP的靶向关系;采用western blot分析miR-122下调对XIAP、Caspase-3和Caspase-7蛋白表达的影响。结果:与Sham组比较,AMI组和空病毒组大鼠心肌组织中miR-122 mRNA的表达、LVEDD和LVESD升高,LVFS和LVEF下降(P<0.05);与AMI组比较,病毒组心肌组织中miR-122 mRNA的表达、LVEDD和LVESD下降,LVFS和LVEF上升(P<0.05)。TUNEL染色显示,AMI组和空病毒组心肌细胞的凋亡水平较Sham组明显增加(P<0.05);与AMI组比较,病毒组心肌细胞的凋亡指数明显下降(P<0.05);荧光素酶报告基因显示miR-122可靶向下调XIAP的表达;Western blot显示,与NC-shRNA细胞比较,miR-122-shRNA细胞中XIAP的蛋白表达明显增加,Caspase-3和Caspase-7的蛋白表达明显下降(P<0.05)。结论:急性心肌梗死后miR-122的表达水平增加,并可能通过靶向XIAP、Caspase-3和Caspase-7的表达,从而调控心肌细胞的凋亡。Objective To investigate the expression of miR-122 in acute myocardial infarction rats and its effect on cardiomyocyte apoptosis.MethodsTotally 80 male SD rats were randomly divided into Sham group,AMI group,empty virus group and virus group,and the rat model of acute myocardial infarction was constructed.The cardiac function index of rats was detected by echocardiography.The mRNA relative expression of miR-122 was analyzed by RT-PCR.The apoptosis of cardiomyocyte in rat was detected by TUNEL staining.The NC-shRNA and miR-122-shRNA stable cell lines were constructed,and the targeting relationship between miR-122 and XIAP was verified using luciferase reporter gene.Western blot was used to analyze the effect of down-regulation of miR-122 on the expression of XIAP,Caspase-3 and Caspase-7.ResultsCompared with Sham group,the miR-122 mRNA expression,LVEDD and LVESD in myocardial tissue of AMI group and empty virus group was significantly increased,while the LVFS and LVEF decreased significantly(P<0.05).Compared with the AMI group,the expression of miR-122 mRNA,LVEDD and LVESD decreased,and LVFS and LVEF increased in the myocardial tissue of the virus group(P<0.05).TUNEL staining showed that the apoptosis of cardiomyocytes in AMI group and empty virus group was significantly higher than that in Sham group(P<0.05),whereas the apoptotic index of cardiomyocytes in the virus group was significantly decreased compared with the AMI group(P<0.05).The luciferase reporter gene showed that miR-122 can down-regulate the expression of XIAP.Western blot showed that compared with NC-shRNA cells,the expression of XIAP in miR-122-shRNA cells was significantly increased,while the expression of Caspase-3 and Caspase-7 was significantly decreased(P<0.05).ConclusionThe expression of miR-122 increased after acute myocardial infarction,and it may regulate the apoptosis of cardiomyocytes by targeting the expression of XIAP,Caspase-3 and Caspase-7.

关 键 词：急性心肌梗死 MIR-122 细胞凋亡 XIAP CASPASE-3 

分 类 号：R542.22[医药卫生—心血管疾病]