miR-126及VEGF在大鼠心肌梗死交界区表达的动态变化  

Changes of miR-126 and VEGF expression levels in myocardium postacute myocardial infarction in rats

作　　者：李国达[1] 刘衍宇[2] 方凌燕[2] 凌云[2] 梁一波[2] 邓玉丽[2] 余丽[1] 

机构地区：[1]广东医学院研究生院,广东湛江524003 [2]广东医学院第二附属医院临床时间医学实验室,广东湛江524003

出　　处：《心脏杂志》2015年第6期639-644,共6页Chinese Heart Journal

基　　金：湛江市科技财政基金竞争项目资助(2014A01032)

摘　　要：目的观察大鼠心肌梗死(MI)后MI交界区微小RNA-126(miR-126)及血管内皮生长因子(VEGF)表达的动态表达变化,初步探讨miR-126及VEGF对缺血局部血管新生的影响。方法雄性SD大鼠结扎冠状动脉左前降支建立急性心肌梗死模型组(AMI组),另设假手术对照组(Sham组),每组30只。于术后7 d、14 d和28 d分别处死10只大鼠,进行MI面积百分比测定,实时荧光定量PCR法检测心梗交界区miR-126、VEGF mRNA表达水平,免疫组织化学方法检测各组大鼠MI交界区VEGF蛋白的表达。结果 Sham组术后7 d、14 d和28 d心肌组织miR-126mRNA和VEGF mRNA的表达均无明显区别,AMI组术后7 d、14 d和28 d,MI交界区mir-126 mRNA表达与相应的Sham组相比,均有不同程度的下降(P<0.01),而VEGF mRNA的表达则均有不同程度的增高(P<0.01);在AMI组,随着MI时间的延长,miR-126和VEGF mRNA的表达均逐渐升高,且在AMI 14 d达到高峰(P<0.05)。VEGF的蛋白表达情况与其基因表达基本一致。结论大鼠MI后VEGF mRNA及其蛋白的表达明显升高的同时伴随miR-126基因表达的降低,随着缺血时间延长,miR-126 mRNA表达有所恢复。AIM To investigate the changes of miR-126 and VEGF expression levels in myocardium post-acute myocardial infarction （AMI） in rats and to explore the effect of miR-126 and VEGF on the angiogenesis in the junctional zone of infarcted region post-AMI. METHODS The left coronary arteries of male rats were ligated to make the models of AMI （ AMI group, n = 30）. The sham-operated group （ n - 30） was established. VEGF in the marginal zone of infarcted region was detected by immunohisto- chemical staining and the expression levels of miR-126 and VEGF mRNA were determined by real-time RT-PCR at 7, 14 and 28 days after operation. RESULTS Compared with those in sham-operated group, the expression levels of miR-126 at the 7th, 14th and 28th day after AMI obviously decreased （P 〈0. 01）, whereas expressions of VEGF mRNA increased to some extent in the model group （P 〈 0. 01 ）. Expression levels of miR-126 and VEGF mRNA show no significant change in the sham group after the 7th, 14th and 28th days. But the expression levels of miR-126 and VEGF mRNA increased over time in the MI group. Peaks of miR-126 and VEGF mRNA expression emerged at day 14 post-AMI andwere then downregulated. Expression levels of VEGF protein and VEGF mRNA were basically the same. CONCLUSION Gene expressions of miR-126 decrease, whereas VEGF mRNA and protein increase post-AMI in rats. miR-126 mRNA recovers to some extent after infarction for some time.

关 键 词：心肌梗死 交界区 血管新生 微小RNA-126 血管生长因子 

分 类 号：R542.2[医药卫生—心血管疾病]