miR-30e-3p调控的自噬在冠状动脉微栓塞致心肌损伤中的作用及机制研究

Coronary microembolization (CME) is an intractable complication of acute coronary syndrome and percutaneous coronary intervention. Previous studies found that cardiomyocyte autophagy was markedly downregulated after CME, while the underlying mechanisms remain obscure. As screened by microarray in our pilot experiments, the expression levels of miR-30e-3p and transcription factor Egr-1, one of its candidate target gene, were both changed in rat hearts with CME and closely related to autophagy, implying a possible regulation of miR-30e-3p in myocardial autophagy via Egr-1 signaling pathway. Here we will establish rat CME models and in vitro oxygen-glucose deprivation (OGD) cardiomyocytes model, then employ luciferase reporter assays and gene-rescue manipulation to confirm the miR-30e-3p / Egr-1 signaling pathway, especially in myocardial autophagy following CME. Furthermore, we will manipulate the expression of miR-30e-3p and its target genes using gene transfection techniques both in vivo and in vitro, to analyze the consequences on myocardial autophagy and their effect on myocardial injury and cardiac function. Moreover, we then test the activation of distinct autophagy-related signaling pathways and screen the possible underlying molecular mechanisms. This work will be greatly helpful to elucidate the specific role of miR-30e-3p / Egr-1 signaling pathway in myocardial autophagy following CME and provide new insight into the prevention and treatment against CME.

冠状动脉微栓塞（CME）是急性冠脉综合征及其介入治疗的严重并发症。前期研究发现CME后心肌自噬水平明显下调，但相关的具体作用和调控机制尚不明确。我们在预实验中筛选发现miR-30e-3p及其潜在靶基因Egr-1均在CME时出现表达变化，可能与自噬相关，由此推测该信号系统可能在心肌自噬参与CME致心肌损伤的过程中起调节作用。本项目拟以大鼠CME模型和缺氧-缺糖心肌细胞模型为基础，用双荧光素酶报告基因系统验证miR-30e-3p对Egr-1的具体调控；进而分别在组织和细胞水平通过基因转染调控miR-30e-3p及Egr-1的表达水平，观察CME后心肌细胞自噬水平、心肌损伤及心功能的变化；并进一步分析相关自噬信号通路的激活情况，探讨相应分子机制。本研究有望阐明miR-30e-3p调控CME后心肌自噬的具体作用机制，揭示新的关键调控因素，为临床防治CME致心肌损伤提供新思路和干预靶点。

冠状动脉微栓塞（CME）是急性冠脉综合征及其介入治疗的严重并发症。前期研究发现CME后心肌自噬水平明显下调，但相关的具体作用和调控机制尚不明确。我们在预实验中筛选发现miR-30e-3p及其潜在靶基因Egr-1均在CME时出现表达变化，可能与自噬相关，由此推测该信号系统可能在心肌自噬参与CME致心肌损伤的过程中起调节作用。本项目首先成功构建大鼠CME模型和缺氧-缺糖心肌细胞模型，双荧光素酶报告基因系统证实miR-30e-3p可靶向调控Egr-1的表达，动物研究结果发现CME大鼠模型中心肌组织miR-30e-3p表达水平下调，心肌自噬被抑制，心脏功能下降；Egr-1/Bim/Beclin-1 信号通路通过调控心肌细胞自噬及凋亡参与CME致心肌损伤。细胞研究结果发现新生大鼠原代心肌细胞缺氧-缺糖模型中，miR-30e-3p表达水平下调，心肌细胞自噬被抑制，细胞凋亡增多，心肌细胞损伤增加；上调miR-30e-3p可起到增加心肌细胞自噬，减少细胞凋亡，降低细胞损伤；在缺血缺氧环境中，Egr-1作用使心肌细胞自噬被抑制，细胞凋亡增多，心肌细胞损伤增加；Egr-1/Bim/Beclin-1 信号通路通过调控心肌细胞自噬及凋亡参与缺血缺氧致心肌细胞损伤；本研究阐明miR-30e-3p调控CME后心肌自噬的具体作用机制，揭示新的关键调控因素，为临床防治CME致心肌损伤提供新思路和干预靶点。