Novel mechanism mediating LPA-induced smooth muscle cell and vascular responses

介导 LPA 诱导平滑肌细胞和血管反应的新机制

• 批准号: 9383988
• 负责人: MEI-ZHEN CUI
• 金额: $ 46.1万
• 依托单位: UNIVERSITY OF TENNESSEE KNOXVILLE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9383988
• 关键词: Adhesions; Animal Model; Apolipoprotein E; Arterial Fatty Streak; Arteries; Atherosclerosis; Automobile Driving; Binding Sites; Blood Vessels; Cardiovascular Diseases; Cause of Death; Cell Lineage; Cell membrane; Cells; Cellular biology; Collaborations; Complex; Coronary; Cytoskeleton; Data; Development; Diet; Ensure; Event; Foam Cells; Focal Adhesion Kinase 1; Goals; Grant; High Fat Diet; Human; Integrin Signaling Pathway; Integrin alpha6beta1; Integrins; Investigation; Knock-in; Knock-in Mouse; Knock-out; Knockout Mice; LDL-Receptor Related Protein 1; Lesion; Lipids; Lysophosphatidic Acid Receptors; Lysophospholipids; Mediating; Mediator of activation protein; Membrane; Methods; Molecular; Mus; Muscle Cells; Nature; Oryctolagus cuniculus; Pathogenesis; Pathologic; Pathway interactions; Phosphotransferases; Plasma; Play; Prevention; Pseudopodia; Regulation; Role; Scientist; Signal Transduction; Small Intestines; Smooth Muscle Myocytes; Testing; United States; Vascular Diseases; Vascular Smooth Muscle; atherogenesis; base; cell motility; cell type; cyr61 protein; disability; in vivo; innovation; insight; knock-down; lipid mediator; lysophosphatidic acid; macrophage; migration; monocyte; mouse model; mutant; novel; paxillin; prevent; receptor; response; restenosis; success; vascular smooth muscle cell migration

ABSTRACT Vascular smooth muscle cell (SMC) migration is a critical event in neointimal formation in the development of atherosclerosis and restenosis, Lysophosphatidic acid (LPA), is emerging as an important lipid mediator of the cellular events contributing to atherosclerosis. During the last grant period, using an LPA receptor knockout mouse model, we identified LPA receptor 1 as the major cell membrane receptor mediating LPA-induced SMC migration and neointimal formation. We also discovered the matricellular protein Cyr61 as the key molecule mediating LPA signaling, leading to SMC migration and neointimal formation. These findings established a new concept that Cyr61 bridges the LPA and integrin signaling pathways, leading to focal adhesion kinase (FAK) activation/SMC migration and neointimal formation. In this grant period, we propose to extend our investigation to identify the molecular mechanism by which LPA-Cyr61 induces SMC migration and the LPA-Cyr61 pathway contribution to atherogenesis. Very recently lineage-tracing studies reveal that a large portion of macrophage marker-positive cells in mouse and human atherosclerotic lesions are vascular SMC-derived cells, suggesting SMC migration/proliferation and differentiation play important roles in atherogenesis. Understanding of SMC migration mechanism will significantly contribute to understanding atherogenesis. To date, little is known about the nature and spatial-temporal regulation of the migration which drives kinases in the polarized leading edge of SMCs. Interestingly, our recent study revealed several exciting novel findings: 1) the novel pseudopodium- enriched atypical kinase 1 (PEAK1) activation is localized in the polarized leading edge of SMCs upon LPA treatment; 2) Cyr61 induces PEAK1 activation and 3) knockdown of PEAK1 blocked SMC migration, suggesting PEAK1 functions as a downstream key mediator of Cyr61, regulating SMC migration. Furthermore, we discovered that PEAK1 interacts with FAK, a key regulator of cell migration. We also observed that phosphorylated PEAK1 levels are highly increased in ApoE-/- atherosclerotic lesions. The function of the novel kinase PEAK1 in vascular disease is unknown. Our data suggest that PEAK1 is the novel mediator for FAK activation and SMC migration. Based on these new observations, we hypothesize that the LPA receptor- Cyr61-integrin-PEAK1-FAK axis mediates SMC cytoskeleton reorganization/migration and lesion formation in atherosclerosis. These hypotheses will be tested in the following specific aims. Aim 1: Determine the novel role of PEAK1/FAK interaction on the activation of the Src/PEAK1/FAK/Paxillin/Rac pathway and SMC migration. Aim 2: Dissect the novel mechanism by which Cyr61 interacts integrin-adhesion complex signaling, leading to membrane protrusion and cell migration using unique Cyr61 mutant SMCs from novel Cyr61dm/dm knock-in mice. Aim 3: Establish the roles of LPA receptors and Cyr61 in the development of atherosclerosis using our innovative LPA receptor/ApoE knockout, Cyr61dm/dm/ApoE-/- and SMC lineage tracing mouse models. The proposed studies are expected to identify novel targets for prevention and treatment of atherogenesis

摘要 血管平滑肌细胞(SMC)迁移是血管内膜形成过程中的关键事件。 动脉粥样硬化和再狭窄，溶血磷脂酸(LPA)，正在成为一种重要的脂质介质。 导致动脉粥样硬化的细胞事件。在最后的授权期内，使用LPA受体基因敲除 小鼠模型中，LPA受体1是介导LPA诱导的SMC的主要细胞膜受体 移行和新生内膜形成。我们还发现基质细胞蛋白Cyr61是关键分子 介导LPA信号转导，导致SMC迁移和新生内膜形成。这些发现建立了一个新的 Cyr61连接LPA和整合素信号通路，导致粘着斑激酶(FAK) 激活/SMC迁移与新生内膜形成。在这一授权期内，我们建议延长我们的调查 LPA-Cyr61诱导SMC迁移及LPA-Cyr61途径的分子机制 对动脉粥样硬化形成的贡献。最近的谱系追踪研究表明，很大一部分巨噬细胞 小鼠和人类动脉粥样硬化病变中的标记阳性细胞是血管SMC来源的细胞，提示 SMC的迁移、增殖和分化在动脉粥样硬化形成中起重要作用。对SMC的理解 迁移机制将对了解动脉粥样硬化的发生有重要意义。到目前为止，人们对此知之甚少 驱动极化前沿中的激酶的迁移的性质和时空调节 SMC的。有趣的是，我们最近的研究揭示了几个令人兴奋的新发现：1)新的伪足- 富集型非典型激酶1(PEAK1)的激活定位于LPA上SMC的极化前沿 2)Cyr61诱导PEAK1激活；3)敲除PEAK1阻断SMC迁移； 提示PEAK1作为Cyr61下游的关键调节因子，调节SMC的迁移。此外， 我们发现PEAK1与FAK相互作用，FAK是细胞迁移的关键调节因子。我们还观察到， 在ApoE-/-动脉粥样硬化病变中，磷酸化的PEAK1水平高度升高。论小说的功能 激酶PEAK1在血管疾病中的作用尚不清楚。我们的数据表明PEAK1是FAK的新的介导物 激活和SMC迁移。基于这些新的观察结果，我们假设LPA受体- Cyr61-整合素-PEAK1-FAK轴介导SMC细胞骨架重组/迁移和病变形成 动脉硬化。这些假设将在以下具体目标中得到检验。目标1：确定新角色 研究PEAK1/FAK相互作用对Src/PEAK1/FAK/paxlin/Rac通路激活和SMC迁移的影响。 目的2：剖析Cyr61与整合素-黏附复合体信号相互作用的新机制，导致 新型Cyr61dm/dm基因敲入的独特Cyr61突变型SMC膜突起和细胞迁移 老鼠。目的3：建立LPA受体和Cyr61在动脉粥样硬化发生发展中的作用 创新的LPA受体/ApoE基因敲除，Cyr61dm/dm/ApoE-/-和SMC血统追踪小鼠模型。这个 拟议的研究有望确定预防和治疗动脉粥样硬化的新靶点。