Project 2 - Shh and Etv2 Signaling Pathways and Cardiovascular Repair in Mouse and Pig

摘要 心血管疾病是常见且致命的疾病。虽然低等生物有巨大的能力 成年哺乳动物心脏的再生能力和肌肉化能力受到更大的限制 损伤后的受损组织，如心肌梗塞。最近，我们定义了一种进化 在Newt和小鼠中保守的Shh信号通路促进心肌细胞的体外和 心脏修复。我们的初步数据支持Gli1(Shh的下游效应器)是一个直接的 Sox4基因上游调控因子和Gli1过表达促进心肌细胞增殖 体外培养。此外，我们已经证明ETV2是内皮细胞系的主要调节者，并且是 对小鼠和猪的血管生成是必要和充分的。重要的是，这些研究的结果提供了一个 为拟议的研究平台，将剖析管理心血管修复和 扩散。因此，我们的总体假设是Shh下游效应器Gli1/Gli2调节 Sox4依赖的心肌细胞增殖和ETV2促进血管内皮细胞增殖 发展共同促进心脏再生。在这些拟议的研究中，我们将使用 我们实验室中可获得的一些新的遗传模型和大型动物模型(以及核心)， 我们开发的生物信息学算法，我们采用一种创新的方法来剖析Gli1的作用， ETV2和Sox4是调控心血管修复和增殖的重要因素。来检查我们的 根据假设，经修订的项目2提案将涉及以下具体目标：具体目标1： 明确Gli和ETV2缺陷心脏的生长和再生能力；具体目标2： 确定Gli1和ETV2过表达对心脏修复和再生的影响以及特异性 目的#3：明确Sox4在心肌细胞谱系中的机制作用。这些目标将 与其他项目相辅相成、协同增效。他们将利用我们最近培育的基因小鼠 模型，可诱导的病毒载体，改良的mRNA-GFP结构，小鼠和猪模型，分子分析 和生物信息学算法，全面定义Gli1、ETV2和Sox4作为基本因素的作用 通过促进心肌细胞增殖和血管生成来管理心脏修复和再生 在受伤之后。鉴于心血管疾病在我们的社会中的巨大发病率和死亡率， 这项提议的潜在影响是巨大的。

ABSTRACT Cardiovascular disease is common and deadly. While lower organisms have a tremendous capacity for regeneration, the adult mammalian heart is more limited in its capacity for regeneration and remuscularization of the damaged tissue following an injury such as a myocardial infarction. Recently, we defined an evolutionary conserved Shh signaling pathway in newt and mouse that promotes cardiomyocyte proliferation in vitro and cardiac repair. Our preliminary data support the hypothesis that Gli1 (a downstream effector of Shh) is a direct upstream regulator of Sox4 gene expression and Gli1 overexpression promotes cardiomyocyte proliferation in vitro. Furthermore, we have demonstrated that Etv2 is a master regulator of the endothelial lineage and is necessary and sufficient for angiogenesis in mouse and pig. Importantly, the results of these studies provide a platform for the proposed studies that will dissect the mechanisms that govern cardiovascular repair and proliferation. Therefore, our overall hypothesis is that the Shh downstream effectors, Gli1/Gli2, regulate cardiomyocyte proliferation in a Sox4 dependent manner and Etv2 promotes endothelial/vascular development to collectively promote cardiac regeneration. In these proposed studies, we will use a number of novel genetic models and large animal models that are available in our laboratory (and the cores), bioinformatics algorithms that we developed and we take an innovative approach to dissect the role of Gli1, Etv2 and Sox4 as important factors that govern cardiovascular repair and proliferation. To examine our hypotheses, the revised Project 2 proposal will address the following specific aims: Specific Aim #1: To define the capacity of Gli and Etv2 deficient hearts for growth and regeneration; Specific Aim #2: To determine the impact of Gli1 and Etv2 overexpression on cardiac repair and regeneration and Specific Aim #3: To define the mechanistic role of Sox4 in the cardiomyocyte lineage. These aims will complement and synergize with the other projects. They will utilize our recently engineered genetic mouse models, inducible viral vectors, modified mRNA-GFP constructs, mouse and pig models, molecular analyses and bioinformatics algorithms to comprehensively define the role for Gli1, Etv2 and Sox4 as essential factors that govern cardiac repair and regeneration by promoting cardiomyocyte proliferation and angiogenesis following injury. Given the tremendous morbidity and mortality of cardiovascular disease in our society, the potential impact of this proposal is tremendous.