Adhesion Signaling in Vascular Growth and Development

描述（申请人提供）：平滑肌细胞（SMC）的增殖和迁移是血管发生和血管成熟过程中的关键过程，在几种主要心血管疾病状态（如动脉粥样硬化、球囊血管成形术后再狭窄和高血压）的病理生理中起重要作用。有证据表明，SMC在发育和疾病期间的有丝分裂反应是由细胞外基质（ECM）蛋白和通过整合素相关蛋白酪氨酸激酶、局灶黏附激酶（FAK）的信号传导调节的。有趣的是，我们发现FAK的主要抑制形式FRNK （FAK相关非激酶）的表达仅限于SMC，在大血管中观察到特别高的水平。我们假设在SMC中，FRNK通过改变粘附依赖性生长因子信号来调节生长和发育。因此，FRNK可能被证明是血管内操作后SMC生长失调的有效治疗靶点。我们建议采用生化和遗传学方法来表征FRNK在血管生长和发育中的作用。本研究的具体目的如下：1)明确FRNK在血管SMC中抑制生长因子和黏附依赖性细胞增殖和迁移的机制。我们将通过DNA合成和趋化分析来描述哪些SMC有丝分裂原受FAK/FRNK信号调控，并定义FRNK过表达改变的信号通路。特别强调的是确定FRNK在SMC中减弱生长因子信号的机制。2)研究发育过程中FRNK表达的体内调控。我们将采用组织特异性原位方法来表征发育小鼠中的FRNK表达模式。3)评价FAK/FRNK信号在血管生长发育中的功能作用。我们将采用转基因基因靶向方法来确定sm特异性过表达FRNK对血管发育的影响。

DESCRIPTION (provided by applicant): Proliferation and migration of smooth muscle cells (SMC) are critical processes during vasculogenesis and blood vessel maturation and are important in the pathophysiology of several prominent cardiovascular disease states such as atherosclerosis, restenosis following balloon angioplasty, and hypertension. Evidence suggests that the mitogenic responses of SMC during development and disease are modulated by extracellular matrix (ECM) proteins and signaling through the integrin-associated protein tyrosine kinase, focal adhesion kinase (FAK). Interestingly, we have shown that the expression of FRNK (FAK Related Non-Kinase), a dominant-inhibitory form of FAK is restricted to SMC with particularly high levels observed in large blood vessels. We hypothesize that in SMC, FRNK regulates growth and development by modifying adhesion-dependent growth factor signaling. As such, FRNK may prove an effective therapeutic target for disregulated SMC growth following endovascular manipulation. We propose to employ biochemical and genetic approaches to characterize the role of FRNK in vascular growth and development. The specific aims of this proposal are as follows: 1) Define the mechanism by which FRNK attenuates growth factor and adhesion-dependent cell proliferation and migration in vascular SMC. We will characterize which SMC mitogens are regulated by FAK/FRNK signaling using DNA synthesis and chemotaxis assays and define the signaling pathways altered by FRNK overexpression. Particular emphasis will be placed on defining the mechanism by which FRNK attenuates growth factor signaling in SMC. 2) Study the in vivo regulation of FRNK expression during development. We will employ tissue-specific in situ approaches to characterize FRNK expression patterns in the developing mouse. 3) Evaluate a functional role for FAK/FRNK signaling in vascular growth and development. We will employ a transgenic gene targeting approach to determine the effect of SM-specific overexpression of FRNK on vascular development.