Alcohol Regulation of Smooth Muscle Migration and Growth

描述(由申请人提供)： 流行病学研究将适度饮酒与心血管疾病发病率的降低联系在一起。此外，动物研究表明，乙醇对动脉粥样硬化病变的发展和进展以及球囊损伤后新生内膜的形成具有抑制作用。然而，调节这些有益效果的确切机制尚不清楚。机械力诱导的动脉平滑肌细胞(SMC)增殖、凋亡和迁移是动脉粥样硬化发病机制和动脉损伤反应的重要过程。一些研究支持蛋白水解酶(尿激酶型纤溶酶原激活物(UPA)和基质金属蛋白酶(MMPs)及其抑制物)在调节SMC增殖、凋亡和迁移中的作用。事实上，我们以前已经证明，脉冲压力诱导的SMC迁移依赖于uPA和MMPs。此外，裸露损伤后，基质金属蛋白酶-9-/-动脉中的SMC迁移和复制受到损害。整合素参与多种信号通路，是机械力诱导的SMC事件的关键介质。作为SMC功能的机械转导和调节因子，值得特别注意的是整合素受体α-v-beta3。有趣的是，最近的研究表明，α-v-beta3参与了血管细胞中基质金属蛋白酶的表达和活性的调控。我们的初步数据还表明，乙醇对血清刺激的SMC在“静态”培养中的增殖和迁移以及对脉冲压力刺激的MMP2和MMP9的表达和活性具有抑制作用。基于这些观察和文献报道，我们的中心假设是乙醇对心血管疾病起到保护作用，部分是通过抑制血管SMC的迁移和增殖。具体地说，我们假设乙醇通过调节机械力激活的整合素α-v-β3受体信号和随后的蛋白酶表达和活性来控制SMC的迁移、增殖和凋亡，从而控制血管重塑。利用灌流的跨毛细血管培养系统和Flexpercell应变装置，分别将人SMC暴露于明确的、生理相关的脉冲压力和循环应变下，我们建议确定乙醇对机械力诱导的SMC生长(增殖和凋亡)和迁移的影响，并阐明相关的信号机制。由于心血管疾病并发症的死亡率如此之高，破译一种物质预防它的机制显然具有重大的临床重要性和意义。因此，明确乙醇在改善机械力诱导的SMC增殖、凋亡和迁移中的保护作用是至关重要的，这些过程是新生内膜形成的标志，是心血管疾病发展的组成部分。

DESCRIPTION (provided by applicant): Epidemiological studies associate moderate alcohol consumption with a reduced incidence of cardiovascular disease. Moreover, animal studies demonstrate an inhibitory effect of ethanol ol the development and progression of atherosclerotic lesions and on neointimal formation following balloon injury. However, the precise mechanisms mediating these beneficial effects are unknown. Mechanical force-induced arterial smooth muscle cell (SMC) proliferation, apoptosis and migration are distinct processes that play an important role in the pathogenesis of atherosclerosis and the arterial response to injury. Several studies support a role for proteases, (urokinase plasminogen activator (uPA) and matrix metalloproteinases (MMPs) and their inhibitors), in regulating SMC proliferation, apoptosis and migration. Indeed, we have previously demonstrated that pulse pressure-induced SMC migration is dependent on uPA and MMPs. Furthermore, SMC migration and replication is impaired in MMP-9 -/- arteries following a denuding injury. Integrins participate in several signaling pathways and are key mediators of mechanical force-induced events in SMC. Of particular notice as a mechano transducer and regulator of SMC function is integrin receptor alpha-v-beta3. Interestingly, recent studies have implicated alpha-v-beta3 in the control of MMP expression and activity in vascular cells. Our preliminary data also demonstrate an inhibitory effect of ethanol on serum stimulated SMC proliferation and migration in 'static' cultures, and on pulse pressure-stimulated MMP-2 and MMP-9 expression and activity. Based on these observations and reports in the literature, our central hypothesis is that ethanol exerts its protective effect on cardiovascular disease, in part, by inhibiting vascular SMC migration and proliferation. Specifically, we hypothesize that ethanol controls the migration, proliferation and apoptosis of SMC, and thus vascular remodeling, by modulating mechanical force activated integrin alpha-v-beta3 receptor signaling and subsequent protease expression and activity. Using a perfused transcapillary culture system in conjunction with a Flexercell strain apparatus to expose human SMC to defined, physiologically relevant pulse pressures and cyclic strains, respectively, we propose to define the effects of ethanol on mechanical force-induced SMC growth (proliferation and apoptosis) and migration and to elucidate the signaling mechanisms involved. Because the mortality from the complications of cardiovascular disease is so high, deciphering the mechanism whereby a substance can protect against it is clearly of major clinical importance and significance. Accordingly, it is critical to define the protective role of ethanol in ameliorating mechanical force-induced SMC proliferation, apoptosis and migration, processes which are hallmarks of neointimal formation and which are integral to the development of cardiovascular disease.