微小RNA-21在大鼠严重烫伤早期心肌组织中的表达变化及作用机制  

Expression of microRNA-21 in myocardial tissue of rats in the early stage of severe scald injury and its mechanism

作　　者：谢琼慧[1] 赵超莉[1] 叶子青[1] 杨飞[1] 阮琼芳[1] 谢卫国[1] 

机构地区：[1]武汉大学同仁医院,武汉市第三医院烧伤研究所430060

出　　处：《中华烧伤杂志》2014年第4期315-319,共5页Chinese Journal of Burns

基　　金：武汉市卫生局科研项目（WX13A08）;武汉市科技局重点攻关项目（20056007071）

摘　　要：目的 观察大鼠严重烫伤早期心肌组织中微小RN A-21以及程序性细胞死亡因子4 （PDCD4）的表达变化,在细胞水平验证两者关系,初步探讨微小RN A-21参与大鼠严重烫伤早期心肌损害的分子机制，方法 （1）将40只SD大鼠按随机数字表法分为假伤组8只（致假伤）和烫伤组32只（背部致30％ TBSAⅢ度烫伤），假伤组伤后不予补液,lh后处死取左心室组织;烫伤组伤后经腹腔注射乳酸林格液,于伤后3、6、12、24 h分别处死8只大鼠取左心室组织.实时荧光定量RT-PCR法检测心肌组织中微小RNA-21的表达水平,蛋白质印迹法检测心肌组织中PDCD4蛋白表达，（2）取大鼠心肌细胞株H9C2按随机数字表法分为微小RNA-21拮抗剂组（转染微小RNA-21拮抗剂）和转染对照组（转染微小RNA拮抗剂阴性对照），转染后48 h实时荧光定量RT-PCR法和蛋白质印迹法分别测定心肌细胞PDCD4的mRNA和蛋白表达水平，对数据行单因素方差分析、ISD-t检验、两独立样本t检验,对大鼠心肌组织微小RNA-21表达与PDCD4蛋白水平行直线相关分析，结果 （1）假伤组伤后lh及烫伤组伤后3、6、12、24 h大鼠心肌组织微小RNA-21的相对表达量分别为0.96±0.13、0.44±0.08、0.42 ±0.10、0.33±0.07、0.61±0.10（F=27.331,P＜0.001），与假伤组伤后1h比较,烫伤组伤后3、6、12、24 h心肌组织微小RNA-21水平均明显下降（t值为4.558～9.410,P值均小于0.01），假伤组伤后1h及烫伤组伤后3、6、12、24 h大鼠心肌组织PDCD4蛋白的相对表达量分别为0.44±0.05、0.60±0.09、0.92±0.15、0.86±0.11、0.57±0.10（F=8.622,P=0.003）,其中烫伤组伤后6、12 h表达量显著高于假伤组伤后1 h（t值分别为4.968和4.122,P值均小于0.01）.烫伤组大鼠各时相点心肌组织微小RN A-21表达水平与PDCD4蛋白表达水平呈明显负相关（r=-0.572,P=0.026），（2）微小RNA-21拮抗剂组心肌细胞PDCD4的mRNA和蛋白的相对表达量分�Objective To explore the molecular mechanism of microRNA-21 in myocardial damage of rats in the early stage of severe scald injury by observing the expression of microRNA-21 and programmed cell death 4 （PDCD4） in myocardial tissue of rat and to validate the relationship between them in cell model.Methods （1） Forty SD rats were divided into sham injury group （n =8,sham injured） and scald injury group （n =32,inflicted with 30% TBSA full-thickness scald on the back） according to the random number table.The left ventricular tissue was collected from rats in sham injury group at post injury hour 1 without any fluid infusion.Rats in scald injury group were given an intraperitoneal injection of lactic acid Ringer＆#39;s solution and 8 rats were respectively sacrificed at post injury hour 3,6,12,24 to harvest left ventricular tissue.The expression of microRNA-21 in myocardial tissue was assessed by real-time fluorescent quantitative RT-PCR.The protein expression of PDCD4 in myocardial tissue was assessed by Western blotting.（2） Rat myocardial cell line H9C2 was divided into microRNA-21 inhibitor group （cells were transfected with microRNA-21 inhibitor） and negative transfection control group （cells were transfected with negative control of microRNA inhibitor） according to the random number table.At post transfection hour 48,real-time fluorescent quantitative RT-PCR and Western blotting were performed respectively to determine the mRNA and protein expression levels of PDCD4 in cells.Data were processed with one-way analysis of variance,LSD-t and two independent samples t test.The relationship between microRNA-21 expression and PDCD4 protein level in myocardial tissue of rats was assessed by linear correlation analysis.Results （1） The expression levels of microRNA-21 in myocardial tissue of rats in sham injury group at post injury hour 1 and in scald injury group at post injury hour 3,6,12,24 were respectively 0.96 ±0.13,0.44±0.08,0.42 ±0.10,0.33±0.07,and 0.61 ±0.10 （F =27.331,P 〈

关 键 词：烧伤 心肌缺血 微小RNA-21 程序性细胞死亡因子4 

分 类 号：R644[医药卫生—外科学]