hiPSC-ECs来源的外泌体通过miRNA-126-3p影响心肌细胞电生理特性参与应激性心肌病发生的机制研究

内皮功能障碍在应激性心肌病患者中常见，但内皮功能障碍后对心肌的调控机制尚不明确。我们前期研究表明高浓度肾上腺素导致hiPSC-ECs分泌的外泌体中miRNA-126-3p表达增高。同时，高浓度肾上腺素延长hiPSC-CMs动作电位时程，导致离子通道功能异常及心律失常。文献表明RGS3抑制G蛋白介导的信号通路。生物信息学预测RGS3是miRNA-126-3p的潜在靶基因。我们由此提出假说：内皮细胞功能障碍后分泌的外泌体转运miRNA-126-3p到心肌细胞并通过RGS3-G蛋白信号通路影响心肌细胞的电生理特性，参与应激性心肌病调控。本项目采用hiPSC-CMs和hiPSC-ECs，应用钙信号与收缩同步记录、膜片钳、分子生物学等技术，探讨hiPSC-ECs源的外泌体通过其转运的miRNA-126-3p对心肌细胞电生理特性的影响及其机制，为探寻新的病理生理机制和寻找新的治疗靶点提供理论依据。

Increasing evidence suggests that endothelial dysfunction is one of the pathogenesis of stress cardiomyopathy which is also known as Takotsubo cardiomyopathy (TTC). However, the exact mechanism of endothelial dysfunction on the TTC myocardium remains unclear. Our previous study has demonstrated that high concentrations of catecholamines lead to a significant elevation of miRNA-126-3p in exosomes secreted by hiPSC-ECs. Furthermore, high concentrations of catecholamines prolonged the action potential duration (APD) and resulted in abnormal ion channels as well as arrhythmias in hiPSC-CMs. Previous reports showed that RGS3 inhibits G protein-mediated signaling pathways. Bioinformatics analysis has predicted RGS3 to be a potential target gene of miR-126-3p. This project aims to test the hypothesis that exosomes secreted by endothelial cells transport miRNA-126-3p to hiPSC-CMs, affecting the ion channel function and electrophysiological properties of hiPSC-CMs through RGS3-G protein signaling pathway, using TTC model of hiPSC-CMs, and multiple techniques including edge detection system, electrophysiology, cellular and molecular biology. The proposed project will provide evidence for elucidating the effect of vascular endothelial dysfunction on myocardial cell function and advance our understanding of the pathophysiology of TTC.