ALCOHOL REGULATION OF SMOOTH MUSCLE MIGRATION AND GROWTH

描述(摘自申请者摘要)：流行病学研究表明，适度饮酒或中风、高血压和冠状动脉疾病(CAD)等心血管疾病的发病率具有显著的保护作用，这些疾病是西方世界死亡的主要原因。此外，活体动物研究表明，乙醇对球囊损伤后新生内膜的形成有抑制作用。机械力诱导的动脉平滑肌细胞(SMC)增殖和迁移是高血压、动脉粥样硬化和动脉损伤反应过程中两个不同的过程，在新生内膜形成中发挥重要作用。一些研究已经为丝裂原激活蛋白激酶(MAPKs)和尿激酶型纤溶酶原激活物(UPA)、纤溶酶原激活物抑制物(PAI-1)和基质金属蛋白酶(MMPs)分别在调节SMC生长和迁移中的作用提供了令人信服的证据。初步的体外数据表明，在没有内皮细胞的情况下，脉动血流增加导致的脉压增加会诱导SMC的增殖、迁移和MAPK信号转导。此外，生理浓度的乙醇可抑制压力和血清诱导的SMC迁移增加，这种作用可通过抑制SMC MAPK信号、uPA和基质金属蛋白酶的表达来模拟。此外，乙醇抑制血清刺激的MAPK信号转导和SMC的生长，这种作用也可以用一种特定的MAPK抑制剂来模拟。中心假设是，生理浓度的乙醇对心血管疾病起到保护作用，部分是通过抑制压力诱导的SMC增殖和迁移增加，减少这些细胞中的MAPK信号。这个最初的独立研究项目旨在确定乙醇对脉压引起的SMC信号、生长和迁移变化的影响。利用一种新的灌流跨毛细管培养系统，内皮细胞和血管平滑肌细胞可以长期暴露在生理剪应力和脉冲压力(脉动流)下，研究人员将确定乙醇在以下方面的剂量和时间效应：(I)脉压诱导的SMC增殖和迁移增加，(Ii)脉压诱导的SMC MAPK、uPA、MMP、PAI-1和TIMP信号的变化，以及(Iii)MAPK信号在调节脉压诱导的UPA、MMP、TIMP和PAI-1表达变化以及随后的SMC迁移和增殖变化中的作用。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，确定乙醇在改善机械力诱导的SMC增殖和迁移中的保护作用是至关重要的，这一过程是新生内膜形成的标志，也是心血管疾病发展的组成部分。

DESCRIPTION (Adapted from Applicant's Abstract): Epidemiological studies demonstrate a significant protective effect of moderate alcohol consumption or the incidence of cardiovascular disorders such as stroke, hypertension and coronary artery disease (CAD) which account for the majority of deaths in the Western world. In addition, in vivo animal studies demonstrate an inhibitory effect of ethanol on neointimal formation following balloon injury. Mechanical force-induced arterial smooth muscle cell (SMC) proliferation and migration are two distinct processes that play an important role in neointimal formation during the pathogenesis of hypertension, atherosclerosis and the arterial response to injury. Several studies have provided compelling evidence for a role of mitogen activated protein kinases (MAPKs) and urokinase plasminogen activators (uPA), plasminogen activator inhibitor (PAI-1), and matrix metalloproteinases (MMP) in regulating SMC growth and migration, respectively. Preliminary in vitro data demonstrate that increases in pulse pressure due to increases in pulsatile flow induces SMC proliferation, migration and MAPK signaling in the absence of endothelial cells. Furthermore ethanol, at physiological concentrations, inhibits pressure- and serum-induced increases in SMC migration, an effect that is mimicked by inhibiting SMC MAPK signaling, uPA and MMP expression. In addition, ethanol inhibits serum-stimulated MAPK signaling and growth of SMC, an effect that is also mimicked using a specific MAPK inhibitor. The central hypothesis is that ethanol at physiological concentrations, exerts its protective effect on cardiovascular disease, in part, by inhibiting pressure-induced increases in SMC proliferation and migration by decreasing MAPK signaling in these cells. This initial independent research project proposes to define the effects of ethanol on pulse pressure induced changes in SMC signaling, growth and migration. Utilizing a novel perfused transcapillary culture system, whereby endothelial and vascular smooth muscle cells can be chronically exposed to physiological shear stress and pulse pressures (pulsatile flow), the investigators will define the dose and temporal effects of ethanol on (i) pulse pressure induced increases in SMC proliferation and migration, (ii) pulse pressure induced changes in SMC MAPK, uPA, MMP, PAI-1 and TIMP signaling and (iii) the role of MAPK signaling in modulating pulse pressure-induced changes in uPA, MMP, TIMP and PAI-1 expression and subsequent changes in SMC migration and proliferation. 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 and migration, processes which are hallmarks of neointimal formation and which are integral to the development of cardiovascular disease.