严重烧伤早期大鼠心肌组织微小RNA-126的表达变化及其与心肌损害的关系  

Expression of microRNA-126 in myocardial tissue of rats in the early stage of severe burn injury and its relation with myocardial damage

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

机构地区：[1]武汉大学同仁医院暨武汉市第三医院烧伤研究所,430060

出　　处：《中华烧伤杂志》2015年第5期367-371,共5页Chinese Journal of Burns

基　　金：武汉市卫计委临床医学科研项目（WX13A08）;武汉市科技计划（2013061402010510）

摘　　要：目的观察严重烧伤早期大鼠心肌组织中微小RNA-126与血清心肌肌钙蛋白I（cTnI）的表达变化以及两者的相关性，并在细胞水平验证微小RNA-126与心肌损害的关系。方法（1）将48只SD大鼠按照随机数字表法分为假伤组8只（致假伤，不予补液）和烧伤组40只（背部造成30％TBSAⅢ度烫伤，以下称烧伤，伤后经腹腔注射乳酸林格液）。假伤组伤后1h收集腹主动脉血，之后处死大鼠取左心室组织；伤后3、6、12、24、48h，烧伤组分别取8只大鼠采集腹主动脉血，之后处死大鼠取左心室组织。实时荧光定量RT—PCR法检测心肌组织中微小RNA-126的表达水平，ELISA法检测血清cTnI水平。（2）将大鼠心肌细胞株H9C2细胞按随机数字表法分为正常对照组（常规培养）、刺激组、阴性转染＋刺激组、转染＋刺激组。刺激组将细胞置于含体积分数10％烧伤大鼠血清的DMEM培养液中行缺氧处理24h；阴性转染＋刺激组、转染＋刺激组分别用微小RNA模拟物阴性对照、微小RNA-126模拟物转染细胞24h后，同刺激组处理。其中烧伤大鼠血清来源于实验（1）伤后6h留取血清。实时荧光定量RT—PCR法检测心肌细胞中微小RNA-126表达（样本数为3），用细胞计数试剂盒8检测心肌细胞活力（样本数为4，数据以吸光度值表示），流式细胞仪检测心肌细胞凋亡率（样本数为3）。对数据行单因素方差分析、LSD—t检验，对大鼠心肌组织微小RNA-126表达与血清cTnI水平行直线相关分析。结果（1）与假伤组伤后1h比较，烧伤组伤后各时相点大鼠心肌组织微小RNA-126表达水平均明显降低（t值为5．68～9．79，P值均小于0．01），其中伤后24h达最低值（0．40±0．08）；与假伤组伤后1h比较，烧伤组伤后各时相点大鼠血清cTnI水平均明显升高（t值为6．68～12．79，P值均小于0．01），其中伤后12h达峰值[（1035±177）pg／mL]。�Objective To observe the changes in the expressions of microRNA-126 in myocardial tissue and cardiac troponin I （cTnI） in serum of rats in the early stage of severe burn injury with analysis of their relationship, and to validate the relationship between microRNA-126 and myocardial damage in cellular level. Methods （ 1 ） Forty-eight SD rats were divided into sham injury group （ n = 8, without fluid ther- apy after sham injury） and burn injury group （ n = 40, inflicted with 30% TBSA full-thickness scald on the back, hereinafter referred to as burn, and received intraperitoneally injection of lactic acid Ringer＇s solution） according to the random number table. Blood was collected from abdominal aorta of rats in sham injury group at post injury hour （PIH） 1 , and then these 8 rats were sacrificed for obtaining left ventricular tissue. Blood was respectively collected from abdominal aorta of 8 rats in burn injury group at PIH 3, 6, 12, 24, and 48, and then they were sacrificed and the left ventrieular tissue was obtained at each time point. The expression of microRNA-126 in myocardial tissue was assessed by real-time fluorescent quantitative RT-PCR. Serum level of cTnI was assessed by ELISA. （2） Rat myocardial cell line H9C2 was divided into normal control group （ NC, routinely cultured） , stimulation group （S） , negative transfeetion ＋ stimulation group （ NT ＋ S） , and transfection ＋ stimulation group （T ＋ S） according to the random number table. Cells in S group were treated with hypoxia for 24 h after being cultured with DMEM containing 10% burn serum obtained from rats in burn injury group at PIH 6 in experiment （ 1 ）. Cells in NT ＋ S group and T ＋ S group were respectively transfected with the negative control of microRNA mimics and microRNA-126 mimics for 24 h, and then were given the same treatment as that of S group. The expression of microRNA-126 in myo- cardial cells was determined by real-time fluorescent quantitative RT-PCR （ with the sample numb

关 键 词：烧伤 缺氧 细胞凋亡 肌钙蛋白I 微小RNA-126 细胞活力 

分 类 号：R644[医药卫生—外科学]