COBRE: WI HOSP OF RI: P57KIP2 IN VENTRICULAR CARDIOMYOCYTE DIFFERENTIATION

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。该建议的重点是细胞周期抑制剂p57 KIP 2在心室肌细胞分化中的作用。先前的研究表明，p57 KIP 2在调节发育中心脏的增殖和分化之间的平衡中起重要作用，并表明其参与引起小鼠薄壁心室肌表型（扩张型心肌病）。我们推测p57 KIP 2在心脏的过度表达会导致心室增殖区的耗竭，并通过引起心肌细胞的早期终末分化而导致心肌表型变薄。本研究的目的是通过检测p57 KIP 2在小鼠和斑马鱼动物中的过度表达来验证这一假设 模型我将追求两个具体目标：1。检查p57 KIP 2在小鼠薄壁心肌表型产生中的作用。- 首先，我将分析p57 KIP 2在已建立的小鼠薄心肌模型中的表达模式。第二，我将通过诱导由肌球蛋白轻链-2心室（MLC-2 v）启动子驱动的Cre-loxP介导的激活来检查小鼠心脏中p57 KIP 2过表达的影响。2.鉴定斑马鱼p57 KIP 2同源物，分离其全长cDNA并对该斑马鱼同源物进行深入分析，包括：-通过整体原位杂交和RT-PCR详细分析其时空表达模式。- 研究p57 KIP 2在斑马鱼中的组成性和心脏特异性过表达的影响。- 研究吗啉代诱导的斑马鱼p57 KIP 2失活的影响。这些实验将为进一步研究P57 KIP 2在扩张型心肌病、心室肥大和心脏再生中的作用奠定基础。了解心肌细胞从细胞周期中退出的机制对于治疗各种心血管疾病都很重要。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This proposal focuses on the role of the cell cycle inhibitor p57KIP2, on the differentiation of ventricular myocytes. Previous studies suggest that p57KIP2 plays an important role regulating the balance between proliferation and differentiation in the developing heart and suggests its involvement in causing a thin-walled ventricular myocardium phenotype (dilated cardiomyopathy) in the mouse. We hypothesize that cardiac over-expression of p57KIP2 depletes the ventricular proliferative zone and leads to a thin myocardium phenotype by causing early terminal differentiation of cardiomyocytes. The goal of this proposal is to test this hypothesis by examining the effects of p57 KIP2 over-expression in the mouse and zebrafish animal models. I will pursue two specific aims: 1. Examine the role of p57KIP2 in the generation of the thin-walled myocardium phenotype in the mouse. - First, I will analyze the pattern of expression of p57 KIP2 in established murine models of thin myocardium. -Second, I will examine the effects of p57 KIP2 over-expression in the mouse heart by inducing Cre-loxP mediated activation driven by the myosin light chain-2 ventricular (MLC-2v) promoter. 2. Identify the zebrafish p57 KIP2 homologue, isolate its full length cDNA and perform in depth analysis of this zebrafish homologue, including: -detailed analysis of its temporal and spatial expression pattern by whole mount in situ hybridization and RT-PCR. -study the effects of the constitutive and cardiac specific over-expression of p57 KIP2 in the zebrafish. -study the effects of the morpholino induced inactivation of p57KIP2 in the zebrafish. These experiments will form the foundation for further investigating the role of P57KIP2 in the settings of dilated cardiomyopathy, ventricular hypertrophy and cardiac regeneration. Understanding the mechanisms underlying withdrawal of cardiomyocytes from the cell cycle will be important for the treatment of a wide range of cardiovascular diseases.