成体心脏依赖内源心肌细胞的增殖缓慢再生，而新生心肌细胞的数目不足以修复受损心脏组织，如何高效激活内源心肌细胞增殖潜能成为亟待解决的问题。蛋白激酶 D（PKD）在心脏重塑中发挥重要作用；Yes相关蛋白（YAP）是调控心肌细胞增殖的关键因子，而PKD对心肌细胞增殖的影响及YAP在其中扮演的角色还未见报道。申请人前期成果发现上皮细胞中PKD调控YAP通路活性，预实验发现PKD抑制剂显著降低人胚胎干细胞（hESCs）来源的心肌细胞的增殖。基于此我们提出如下假设：PKD通过调节YAP活性调控心肌细胞增殖。拟利用hESCs来源的心肌细胞和新生大鼠心肌细胞开展以下研究：（1）明确PKD及PKD各亚型对心肌细胞增殖的影响，探讨各亚型的协同或叠加效应；（2）明确PKD与YAP在调节心肌细胞增殖中的关联及PKD调控YAP的分子机制。以上研究帮助了解内源心肌细胞增殖的分子机制，为促进心肌再生提供新策略和新靶点。

Adult heart can slowly self-renewal and regenerate, which mainly relies on the re-entry of the cell cycle through pre-exiting adult cardiomyocytes. However, cardiomyocytes generated from pre-exiting cardiomyocytes have very limited effect on damaged heart repair, and people are still looking for the way to effectively stimulate adult cardiomyocytes proliferation. Accouding to previous studies, protein kinase D( PKD) plays important role in regulating heart remolding; and Yes-associated protein (YAP) is a key factor in regulating cardiomyocytes proliferation, but the role of PKD and its connection with YAP in cardiomyocytes proliferation still need to be known. Our previous published study has already proved that PKD can regulates YAP pathway activity in intestinal epithelium cells, and our preliminary data showed that the proliferation of human embryonic stem cells (hESCs) derived cardiomyocytes is inhibited while cells were treated with PKD inhibitors. Based on that, we have the following hypothesis: PKD regulates cardiomyocytes proliferation through YAP pathway. We will study this from the following aspects: (1) Identifying the role of PKD and each PKD family member in regulating cardiomyocytes proliferation; (2) Identifying the relationship between PKD and YAP in regulating cardiomyocytes proliferation, and clarifying the mechanism of PKD regulating YAP signal pathway. Our research targets the mechanism of cardiomyocytes cell cycle controlling, and this may provide new target and strategy for heart repair and regeneration.