TRP离子通道在牵张力诱导的人胚胎干细胞分化的心肌细胞成熟中的作用

The research focuses on the role of transient receptor potential channels (TRP) in regulation of hESC-derived ventricular cardiomyocytes (hESC-VCM) mature in response to cyclic stretch. Fundamental understanding of hESC-derived ventricular cardiomyocytes mature mechanisms help us to grasp the process of the development of cardiomyocyte and to find the key regulation of stem cell therapy which has great significance. TRP channels are Ca2+-permeable non-selective cation channels. These channels are regarded as environmental sensors in many types of cells, which is thought to be involved in sensing osmolarity and membrane stretch. However, their roles in hESC-derived ventricular cardiomyocytes (hESC-VCMs) are still unknown. In vivo cardiomyocytes are faced to cyclic stretch. Therefore, to reveal cardiomyocyte mature signaling pathways and mechanisms under mechanical stretch has important implications for the prevention and treatment of cardiovascular disease using stem cell. However, most important problems in this research area have been unresolved. These problems include which TRP channel plays an important role in the cyclic stretch induced cardiomyocyte maturation process; the possibility of using the inhibition of TRP channels as a means to regulate cardiomyocytes maturation. The purpose of this project is to study: (1) which TRP channel play a role in the regulation of cardiomyocyte in response to cyclic stretch and Ca2+ signal transduction and cardiomyocyte maturation in response to cyclic stretch; (2) In order to confirm the functional role of TRP in regulation of hESC-derived ventricular cardiomyocytes, we will construct several TRP plasmids into chronic virus (lentivirus) expression vector separately, and transfected human embryonic stem cell differentiation of cardiomyocytes for overexpression or reducing TRP expression. (3) We will explore how the TRP channel function in stretch-induced cardiomyocyte maturation for further study. These results of this research will provide an important theoretical basis for TRP channel as a regulatory target for stem cell therapy.

本研究主要集中在TRP通道在周期性牵张力作用下对人胚胎干细胞分化来的心肌细胞成熟的机制，对于干细胞治疗具有重大的意义。瞬时感受器电位通道（TRP）是一类重要的阳离子通道家族，并被认为是心肌细胞感知机械牵张和渗透压改变的重要感受器。但是TRP通道在人胚胎干细胞分化的心肌细胞中的作用还不清楚。因此，揭示人胚胎干细胞分化来的心肌细胞在牵张力的作用下成熟信号途径和机制，对于干细胞治疗心血管相关疾病具有重要的意义。本课题旨在研究（一）阐明哪一种TRP离子通道在周期性牵张力作用下调控心肌细胞Ca2+信号转导和心肌细胞成熟。（二）构建TRP离子通道的慢病毒表达载体，并转染人胚胎干细胞分化的心肌细胞，来研究过表达或降低TRP通道蛋白表达对心肌细胞成熟的影响。 (三）我们还将对TRP离子通道激活的具体机制和路径作进一步的研究。研究成果可为将来能否以TRP通道作为干细胞治疗的靶点提供重要的理论依据。

本研究主要集中在 TRP 通道在周期性牵张力作用下对人胚胎干细胞分化来的心肌细胞成熟和分化的机制，对于干细胞治疗心血管相关疾病的控制具有重大的意义。瞬时感受器电位通道（ TRP）是一类重要的阳离子通道家族，并被认为是心肌细胞感知机械牵张和渗透压改变的重要感受器。本课题揭示了TRPV4在周期性牵张力所诱导的心肌细胞重排中有关键性作用。我们还发现TRPV4离子通道在牵张力所引起的心肌细胞钙内流中起重要的作用。..首先，我们采用机械牵拉的设备来模拟周期性牵张力诱导心肌细胞重排，探究TRPV4在周期性牵张力所诱导的心肌细胞重排中的作用，并对其下游的信号通路进行分析。其次，我们着重研究TRPV4在扩张型心肌病病理机制方面的作用。我们用患者特异性诱导的多能干细胞来源的心肌细胞成功建立了扩张型心肌病模型。在此基础上探索有关的钙离子通道在其中的作用。..结果显示TRPV4可以通过Akt信号通路调控周期性牵张力所诱导的心肌细胞重排。扩张型心肌病病人心肌细胞中机械牵张引起的过度钙内流主要是通过TRPV4离子通道进入。而TRPC1, TRPP2, TRPC1, TRPC3, TRPC5 及TRPC6则并不参于机械牵张引起的过度钙内流。在病人心肌细胞中，机械牵张是通过肌动蛋白来激活TRPV4离子通道从而引起过度钙内流。..这些进展已整理成文，发表于8篇科学论文。主要于发表于BBA-Molecular Basis of Disease，Journal of Molecular and Cellular Cardiology, Stem cells等杂志。