Nox1 and Nox4 Containing Oxidases are Required for PDGF-induced Migration of

描述(由申请人提供)：血管平滑肌细胞(VSMCs)的迁移在心血管疾病的进展中起着重要作用。血管平滑肌细胞的迁移与动脉粥样硬化和血管成形术后由于新生内膜形成增加而导致的再狭窄有关。最近的研究表明，血小板衍生生长因子(PDGF)刺激可促进VSMCs ROS的形成和迁移。ROS在调节细胞迁移的细胞通路中扮演着信号分子的角色，但这些ROS的来源、调节其产生的机制以及它们的下游靶标仍不清楚。在这里，我提出了一种机制，通过该机制，NADPH氧化酶NOX1和NOX4都是VSMC迁移所必需的。我推测，PDGF诱导的VSMCs迁移需要基础的NOX4活性和RAC介导的NOX1刺激来调节焦点黏附动力学和肌动蛋白细胞骨架。在这项提议中，我将通过三个目标来评估这一假说。在第一个目标中，我将确定PDGF激活RAC以刺激Nox1并调节改变肌动蛋白聚合的氧化还原敏感信号通路的机制。在目标2中，我将评估NOX4的表达和活性在Rho表达和Rho介导的焦点黏附转换中的作用。第三个也是最后一个目标将通过研究NOX4在新生组织形成中的作用来在体内测试其中一些概念。了解PDGF诱导VSMC迁移的机制对于开发抗击心血管疾病的治疗策略非常重要。

DESCRIPTION (provided by applicant): Migration of vascular smooth muscle cells (VSMCs) plays an important role in cardiovascular disease progression. The migration of VSMCs is associated with atherosclerosis and restenosis after angioplasty due to increased neointima formation. Recent studies demonstrate that platelet derived growth factor (PDGF) stimulation promotes ROS formation and migration of VSMCs. ROS act as signaling molecules in cellular pathways that modulate migration, but the source of these ROS, the mechanisms regulating their production, and their downstream targets remain unclear. Here I propose a mechanism by which both Nox1 and Nox4 NADPH oxidases are required for VSMC migration. I hypothesize that PDGF-induced migration in VSMCs requires basal Nox4 activity and Rac-mediated stimulation of Nox1 to modulate focal adhesion dynamics and the actin cytoskeleton. In this proposal, I will evaluate this hypothesis via three aims. In the first aim, I will determine the mechanism by which PDGF activates Rac to stimulate Nox1 and modulate redox sensitive signaling pathways that alter actin polymerization. In aim 2, I will evaluate the role of Nox4 expression and activity on Rho expression and Rho-mediated focal adhesion turnover in VSMCs. The third and final aim will test some of these concepts in vivo by examining the role of Nox4 in neoinitmal formation. Understanding the mechanism by which PDGF induces VSMC migration is very important to developing therapeutic strategies to combat cardiovascular disease.