Phospholipase D2 regulation of vascular smooth muscle cell migration

描述（由申请人提供）：血管平滑肌细胞（VSMCs）的迁移是血管成形术后动脉粥样硬化和再狭窄过程中的重要事件。细胞迁移是通过膜运输和细胞骨架重组的协调调节实现的。虽然许多研究都集中在VSMCs中细胞骨架重组的调控上，但对膜转运的参与以及细胞骨架重组和膜转运在这些细胞迁移中的协调调节知之甚少。我们的初步数据表明，磷脂酶D2 （PLD2）是磷脂酶D家族的一员，可产生信号脂质磷脂酸（PA），在vsmc的迁移、细胞骨架重组和膜运输中起重要作用。利用脂质体下拉和质谱的结合，我们还鉴定了一些新的PA结合蛋白，这些蛋白揭示了PA细胞功能的新机制。基于我们的研究结果，我们提出pld2产生的PA在VSMC迁移过程中协调调节细胞骨架重组和膜运输。我们将利用一些最新的试剂和独特的跨学科方法，包括分子和细胞生物学、脂质生物学和动物模型，研究PLD2调节体外VSMC迁移的机制，然后在小鼠模型上研究PLD2调节细胞迁移如何促进损伤诱导的血管重塑。提出了三个目标。在目的1中，我们将研究PLD2在VSMCs极化和迁移中的作用。在Aim 2中，我们将阐明pld2控制的膜运输调节VSMC迁移的机制。在Aim 3中，我们将研究PLD2是否在体内调节血管重塑。

DESCRIPTION (provided by applicant): The migration of vascular smooth muscle cells (VSMCs) is an essential event during atherosclerosis and restenosis after angioplasty. Cellular migration is achieved through coordinated regulation of membrane trafficking and cytoskeletal reorganization. While many studies have focused on the regulation of cytoskeletal reorganization in VSMCs, little is known about the involvement of membrane trafficking and the coordinated regulation of cytoskeletal reorganization and membrane trafficking in the migration of these cells. Our preliminary data have suggested that Phospholipase D2 (PLD2), a member of the phospholipase D family that generates the signaling lipid phosphatidic acid (PA), plays important roles in the migration, cytoskeletal reorganization, and membrane trafficking in VSMCs. Using a combination of liposome pull-down and mass spectrometry, we also identified some new PA-binding proteins, which have revealed the novel mechanistic insights into the cellular functions of PA. Based on our findings, we propose that PLD2-generated PA coordinately regulate cytoskeletal reorganization and membrane trafficking during VSMC migration. By using some newly available reagents and a unique interdisciplinary approach including molecular and cell biology, lipid biology, and animal models, we will investigate the mechanisms by which PLD2 regulates VSMC migration in vitro, and then examine how PLD2-regulated cell migration contributes to injury-induced vascular remodeling using mouse models. Three aims are proposed. In Aim 1, we will examine the roles of PLD2 in the polarization and migration of VSMCs. In Aim 2, we will elucidate the mechanisms by which PLD2-controlled membrane trafficking regulates VSMC migration. In Aim 3, we will investigate if PLD2 regulates vascular remodeling in vivo.