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

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 本研究的重点是细胞周期抑制因子p57Kip2在心肌细胞分化过程中的作用。以前的研究表明，p57Kip2在发育中的心脏中起着调节增殖和分化之间的平衡的重要作用，并表明它参与了导致小鼠薄壁心肌表型(扩张型心肌病)的过程。我们假设心脏过度表达p57Kip2会耗尽心室增殖区，并通过导致心肌细胞早期终末分化而导致心肌表型变薄。这项建议的目的是通过检测p57KIP2在小鼠和斑马鱼动物模型中过度表达的影响来检验这一假设。我将追求两个特定的目标：1.检测p57Kip2在小鼠薄壁心肌表型形成中的作用。-首先，我将分析p57KIP2在已建立的小鼠心肌变薄模型中的表达模式。-第二，我将通过诱导肌球蛋白轻链-2心室(MLC-2v)启动子驱动的Cre-loxP介导的激活来检测p57KIP2在小鼠心脏中过表达的影响。2.鉴定斑马鱼p57KIP2同源物，分离其全长cDNA，并对该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p57KIP2在斑马鱼中结构性和心脏特异性过表达的影响。-研究吗啡诱导斑马鱼p57Kip2失活的效果。这些实验将为进一步研究其作用奠定基础。 P57Kip2在扩张型心肌病、心肌肥厚和心脏再生中的表达。了解心肌细胞退出细胞周期的机制对于治疗一系列心血管疾病具有重要意义。

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.