Modulation of cell death and differentiation by myocardin-regulated microRNAs during mammalian development

在心血管发育过程中，心脏及其流出道来源于胚胎内的前体细胞。我的实验室对这些前体细胞如何成为心脏的心肌细胞和流出道的血管平滑肌细胞（VSMC）特别感兴趣。这种特化过程称为分化，调节心脏和流出道分化的分子机制仍不完全清楚。分化过程部分地被程序性细胞死亡所反对，程序性细胞死亡是一个用来描述去除不再需要的细胞的术语。这一过程由Bcl-2蛋白家族调控。来自我实验室的数据表明，在心脏和VSMC分化中起关键作用的心肌蛋白可以通过microRNA的表达影响肌细胞分化并对抗细胞死亡，这反过来又抑制促死亡Bcl-2家族成员，称为Bnip 3和Bnip 3L（即Nix）。心脏和血管平滑肌细胞的细胞死亡和分化是我的研究计划的中心焦点。在接下来的5年周期中，我的团队将确定myocardin如何调节细胞死亡和分化，以及Bnip 3和Nix如何通过信号通路进行调节。我的HQP使用创新的和机械的细胞和分子生物学技术，包括人类诱导多能干细胞（iPSC），可以分化成心肌细胞和VSMC使用市售培养基。此外，我们使用原代啮齿动物心肌细胞和血管平滑肌细胞，以及永生化细胞系来研究我们实验的分子细节，并为在我实验室工作的学员开发更先进的细胞培养技能。我预计，在未来5年内，我的实验室将有3名博士生和3名硕士生毕业。** 科学界对干细胞生物学的浓厚兴趣强烈表明，心血管生理学家和发育生物学家将在研究这一领域更多应用方面时寻求有关心脏和VSMC从前体细胞分化的机制的知识。此外，我的实验室有相当多的经验解剖的控制过程，调节细胞死亡和分化，同时保持坚定的承诺，研究生的培训。总的来说，这项拟议的研究计划是可行的，重要的，并符合NSERC的任务。

During cardiovascular development, the heart and its outflow tract are derived from precursor cells that reside within the embryo. My laboratory is particularly interested in how these precursor cells can become cardiac myocytes of the heart and vascular smooth muscle cells (VSMCs) of the outflow tract. This process of specialization is called differentiation and the molecular mechanisms that regulate differentiation in the heart and outflow tract remain incompletely understood. The process of differentiation is partly opposed by programmed cell death, which is a term used to describe the removal of cells that are no longer necessary. This process is regulated by the Bcl-2 family of proteins. Data from my laboratory has shown that myocardin, which has a critical role in cardiac and VSMC differentiation, can affect both myocyte differentiation and oppose cell death through the expression of microRNAs, which in turn inhibit the pro-death Bcl-2 family members, called Bnip3 and Bnip3L (i.e. Nix).******Cell death and differentiation of cardiac and vascular smooth muscle cells is the central focus of my research program. In the next 5-year cycle, my group will determine how myocardin regulates cell death and differentiation, and how Bnip3 and Nix are regulated by signaling pathways. My HQP use innovative and mechanistic cell and molecular biology techniques, including human induced pluripotent stem cells (iPSCs) that can be differentiated into cardiomyocytes and VSMCs using commercially available media. In addition, we use primary rodent cardiomyocytes and vascular smooth muscle cells, and immortalized cells lines to work out the molecular details of our experiments and develop more advanced cell culture skills of trainees working in my laboratory. I predict that 3 PhD students and 3 MSc students will graduate from my lab over the next 5-years. ******The scientific community's keen interest in stem cell biology strongly suggests that knowledge regarding the mechanisms by which cardiac and VSMCs differentiate from precursor cells will be sought after by cardiovascular physiologists and developmental biologists investigating more applied aspects of this field. Furthermore, my laboratory has considerable experience dissecting the control processes that regulate cell death and differentiation, while maintaining a strong commitment to graduate student training. Collectively, this proposed program of research is feasible, significant, and consistent with the mandate of NSERC.