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生成和血管成熟过程中的关键过程，在几种突出的心血管疾病状态的病理生理学中起重要作用，如动脉粥样硬化、球囊血管成形术后再狭窄和高血压。有证据表明，SMC在发育和疾病过程中的有丝分裂反应受到细胞外基质(ECM)蛋白和整合素相关蛋白酪氨酸激酶(FAK)信号的调节。有趣的是，我们已经发现FAK的一种显性抑制形式--FRNK(FAK相关的非激酶)的表达仅限于SMC，尤其在大血管中观察到高水平的表达。我们假设在SMC中，Frnk通过改变黏附依赖生长因子信号来调节生长发育。因此，对于血管内操作后失控的SMC生长，FRNK可能被证明是一个有效的治疗靶点。我们建议使用生化和遗传学方法来表征FRANK在血管生长和发育中的作用。该提案的具体目的如下：1)明确Frnk抑制血管SMC中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合成和趋化分析确定哪些SMC有丝分裂原受FAK/FRANK信号调节，并确定FRANK过表达改变的信号通路。重点将放在确定Frnk减弱SMC中的生长因子信号的机制上。2)研究发育过程中Frnk基因表达的体内调控。我们将使用组织特异性的原位方法来表征发育中的小鼠的frnk表达模式。3)评价FAK/FRANK信号在血管生长发育中的作用。我们将使用转基因基因打靶的方法来确定SM特异性过表达的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.