微小RNA-370在心肌梗死后纤维化中的作用

目的:本实验研究了心肌梗死后梗死交界部位微核糖核酸-370(miR-370)的表达情况以及其在梗死后纤维化过程中的作用。方法:建立SD大鼠心肌梗死模型,2w后RT-PCR法、Western blotting法检测心肌梗死交界区TGFβ1、TGFβRⅡ、ColⅠα1、ColⅢα1 mRNA和miR-370的表达情况以及TGFβ1、TGFβRⅡ、α-SMA蛋白的表达。分离、培养SD大鼠乳鼠心肌成纤维细胞,AngⅡ、miR-370干预细胞后检测上述指标的变化。荧光素酶报告实验验证TGFβRⅡ是否为miR-370的靶基因。结果:心肌梗死后梗死交界区miR-370的表达下降而TGFβ1、TGFβRⅡ、ColⅠα1、ColⅢα1 mRNA表达以及TGFβ1、TGFβRⅡ、α-SMA蛋白的表达均增加。荧光素酶报告实验证实TGFβRⅡ是miR-370的靶基因。miR-370能够通过降低TGFβRⅡ的表达,抑制AngⅡ导致的TGFβRⅡ以及胶原蛋白表达升高以及肌成纤维细胞的分化效应但是并不能抑制TGFβ1表达。结论:miR-370能够通过与TGFβRⅡmRNA结合,抑制TGFβRⅡ蛋白的表达部分阻断了TGFβ1-TGFβRⅡ及下游信号转导通路发挥抗纤维化效应。

The role of miRN-370 in fibrosis after myocardial infaction

Objective:This study investigated the miR-370 expression of infarction junction after myocardial infarction and its role in the process of fibrosis after infarction. Methods: Myocardial infarction SD rats model,two weeks after RT-PCR method,Western blotting was used to detect myocardial infarct border zone TGFβ1,TGFβRⅡ,ColⅠα1,expression of ColⅢα1 mRNA and miR-370,and TGFβ1,TGFβRⅡ,α-SMA protein expression. Isolated and cμLtured SD neonatal rat cardiac fibroblasts,check these indicators. after AngⅡ,miR-370 treat the cells. using Luciferase reporter experiments to check whether TGFβRⅡ is miR-370 target gene. Results: The expression of miR-370 declined in the farction junction after myocardial infarction but TGFβ1,TGFβR Ⅱ,ColⅠα1,Col Ⅲα1 mRNA expression and the expression of TGFβ1,TGFβRⅡ,α-SMA protein were increased. Luciferase reporter experiments confirmed TGFβRⅡ is a target gene of miR-370. miR-370 could inhibit AngⅡ cause collagen protein and TGFβRⅡ increased myofibroblasts differentiation through reducing the expression of TGFβRⅡ but could not inhibit expression of TGFβ1. Conclusion: miR-370 can be combined with the TGFβRⅡ mRNA,partly inhibited the expression of the protein TGFβRⅡ,blocked TGFβ1-TGFβRⅡ and downstream signal transduction pathway to plays an important role of anti-fibrotic effects.