Focal adhesion kinase in the cardiovascular system

描述（由申请人提供）： 该提案的长期目标是了解粘着斑激酶（FAK）及其在心血管系统中的信号通路的机制和作用。 FAK 是一种细胞质酪氨酸激酶，在整合素介导的信号转导途径以及生长因子受体（包括那些在心血管系统中发挥关键调节作用的受体）的信号转导中发挥着关键作用。与体外研究的结果一致，小鼠中 FAK 基因敲除导致胚胎致死表型，中胚层组织和心血管系统存在重大缺陷。尽管人们对 FAK 与其他蛋白质的相互作用及其在体外细胞信号传导中的作用有了丰富的了解，但对于 FAK 在胚胎发育或成体生物体中的体内功能仍然知之甚少。尽管FAK完全敲除小鼠表明FAK在心血管系统中具有潜在作用，但胚胎致死性使其对于研究FAK在成年动物心血管发育或功能中的作用不是很有用。为了克服FAK全基因敲除小鼠的胚胎致死问题，我们在初步研究中培育了FAK基因侧翼有两个loxP位点的FAK floxed小鼠。我们还产生了在内皮细胞（EC）中表达FAK转基因的转基因小鼠，并获得了在EC或心肌细胞中特异性表达Cre重组酶的转基因小鼠。在此应用中，Aim 1 将通过将 FAK/IoxP 小鼠与 TIE2-Cre 小鼠交配来研究 FAK 在 EC 中血管生成和血管生成中的作用，以创建 EC 特异性 FAK 敲除小鼠，并检查其对胚胎和成年小鼠中血管生成和血管生成的影响。目标2将通过将FAK条件敲除小鼠与表达FAK或其突变体的转基因小鼠杂交，并通过从这些小鼠中分离EC来检查FAK与其他蛋白质、细胞内信号传导途径和包括迁移和增殖在内的细胞功能的相互作用，来研究EC中FAK功能的分子和细胞机制。目标3将通过将FAK/loxP小鼠与心肌细胞特异性Cre小鼠杂交产生心脏特异性FAK条件敲除小鼠并分析其对心脏发育和功能的影响，确定FAK在心脏发育和功能中的作用和机制。这些研究不仅将产生对体内 FAK 信号通路生理功能的重要见解，还将为肿瘤血管生成、心脏肥大和心力衰竭病理改变的潜在新疗法提供关键信息。

DESCRIPTION (provided by applicant): The long-term goals of this proposal are to understand the mechanisms and roles of focal adhesion kinase (FAK) and its signaling pathways in the cardiovascular system. FAK is a cytoplasmic tyrosine kinase that plays a key role in integrin-mediated signal transduction pathways as well as in signal transduction by growth factor receptors including those that play critical regulatory roles in the cardiovascular system. Consistent with these results from in vitro studies FAK gene knockout in mice resulted in an embryonic lethal phenotype with major defects in the axial mesodermal tissues and cardiovascular system. Despite the abundant knowledge of FAK interaction with other proteins and its roles in cell signaling in vitro, still relatively little is known about the in vivo Functions of FAK in embryonic development or in the adult organisms. Although the FAK total knockout mice suggested a potential role for FAK in the cardiovascular system, the embryonic lethality made it not very useful for studies on the role of FAK in cardiovascular development or functions in the adult animal. To overcome the problem of embryonic lethality of the FAK total knockout mice, we have generated FAK floxed mice with the FAK gene flanked by two loxP sites in preliminary studies. We have also generated transgenic mice with FAK transgene expression in the endothelial cells (ECs) and obtained transgenic mice with specific expression of Cre recombinase in ECs or cardiomyocytes. In this application, Aim 1 will investigate the role of FAK in ECs in [vasculogenesis and angiogenesis by breeding the FAK/IoxP mice with the TIE2-Cre mice to create EC-specific FAK knockout mice and examine the effects on vasculogenesis and angiogenesis in the embryo and in adult mice. Aim 2 will study molecular and cellular mechanism of FAK function in ECs by crossing the FAK conditional knockout mice with transgenic mice expressing FAK or its mutants and by isolating ECs from these mice to examine FAK interaction with other proteins, intracellular signaling pathways and cellular functions including migration and proliferation. Aim 3 will determine the role and mechanism of FAK in cardiac development and function by crossing FAK/loxP mice with cardiomyocyte specific Cre mice to generate heart specific FAK conditional knockout mice and analyzing the effects on the development and function of the heart. These studies will generate not only significant insights into the physiological function of FAK signaling pathways in vivo but also critical information for potential new therapies for pathological alterations in tumor angiogenesis and cardiac hypertrophy and heart failure.