Role of Syntaxin 6 Regulated Post-Golgi Trafficking in Angiogenesis

描述（由申请人提供）：突触融合蛋白6在血管生成中调节高尔基体后运输的作用是指从预先存在的脉管系统建立新血管。血管生成功能障碍可导致几种恶性、炎性和缺血性疾病。新血管形成涉及多个细胞过程，包括细胞增殖和迁移、细胞-细胞和细胞-基质粘附相互作用以及管形态发生。“膜筏”是富含鞘脂和固醇的质膜区域。这些结构域还富含信号蛋白，包括某些激酶、整合素和血管内皮生长因子受体-2（VEGFR 2），所有这些都被认为在血管生成中起作用。迄今为止，膜筏和相关成分的细胞内运输在血管生成中的作用仍不清楚。我们以前已经确定了一个新的作用，囊泡融合蛋白syntaxin 6（syn 6）在交付筏相关的脂质和蛋白质的质膜（PM）。我们的长期目标是了解膜筏组分的运输影响细胞运动的机制。这项研究的总体目标是确定的分子机制，内向外贩运和交付的“膜筏”组件的内皮细胞表面，并检查这些过程中的血管生成过程中的细胞运动的调节的重要性。总的来说，我们的团队在多种功能丧失方法，活细胞成像，分子和细胞生物学技术以及几种体外和体内血管生成模型方面具有专业知识，这将使我们能够解决内皮细胞中的这些重要问题。在目标1中，我们将使用体外研究来评估细胞运动性如何受到PM处膜筏组成的syn 6依赖性调节的影响。为此，我们将评估膜结构域的形成，招聘，组织，激活和动力学的局灶性粘附相关蛋白。在目标2中，我们将进行体外研究，以阐明分泌运输和VEGFR 2递送到PM背后的分子机制。在目标3中，我们将使用体外和体内模型系统来测试syn 6调节的膜筏组件的运输的功能意义，更具体地说，VEGFR 2，相对于内皮管形态发生和血管生成。这些研究的发现将开始阐明syn 6介导的膜运输调节血管生成的机制，并可能为促或抗血管生成疗法提供新的候选靶点。血管生成涉及从先前存在的血管形成新的血管，并且在健康和多种疾病中起重要作用。通过细胞表面定位的血管内皮生长因子受体2（VEGFR 2）和“膜筏”的信号传导在血管生成中起关键作用。然而，我们对维持VEGFR 2和筏组件定位到细胞表面的运输途径的知识是有限的。通过研究和了解血管生成调节分子的运输，我们可以确定一个新的治疗靶点。

DESCRIPTION (provided by applicant): Role of syntaxin 6 regulated post-Golgi trafficking in angiogenesis refers to the establishment of new vessels from preexisting vasculature. Dysfunctions in angiogenesis can lead to several malignant, inflammatory, and ischemic disorders. New vessel formation involves multiple cellular processes, including cellular proliferation and migration, cell-cell and cell-matrix adhesion interactions, and tube morphogenesis. "Membrane rafts" are regions of the plasma membrane that are enriched in sphingolipids and sterols. These domains are also enriched in signaling proteins including certain kinases, integrins and vascular endothelial growth factor receptor-2 (VEGFR2), all of which are believed to play roles in angiogenesis. To date, the roles that membrane rafts and the intracellular trafficking of associated components play in angiogenesis remain unclear. We have previously identified a novel role for the vesicle fusion protein syntaxin 6 (syn6) in the delivery of raft-associated lipids and proteins to the plasma membrane (PM). Our long-term objective is to understand the mechanism(s) by which the trafficking of membrane raft components influences cell motility. The overall goals of this research proposal are to define the molecular mechanisms that underlie inside-out trafficking and the delivery of "membrane raft" components to the endothelial cell surface, and to examine the importance of these processes in the regulation of cellular motility during angiogenesis. Collectively, our group has expertise in multiple loss-of-function approaches, live- cell imaging, molecular and cell biological techniques, and several in vitro and in vivo angiogenesis models, and this will allow us to address these important questions in endothelial cells. In Aim 1, we will use in vitro studies to assess how cell motility is affected by syn6-dependent modulation of membrane raft composition at the PM. To this end, we will evaluate the membrane domain formation, recruitment, organization, activation, and dynamics of focal adhesion-associated proteins. In Aim 2, we will perform in vitro studies to unravel the molecular mechanism behind secretory transport and delivery of VEGFR2 to the PM. In Aim 3, we will use both in vitro and in vivo model systems to test the functional significance of syn6-regulated trafficking of membrane raft components generally, and of VEGFR2 more specifically, with respect to endothelial tube morphogenesis and angiogenesis. Findings from these studies will begin to unravel the mechanisms by which syn6-mediated membrane trafficking regulate angiogenesis, and may provide novel candidate targets for pro- or anti- angiogenic therapies. PUBLIC HEALTH RELEVANCE Angiogenesis involves the formation of new vessels from preexisting ones, and plays an important role in health and several diseases. Signaling via the cell surface-localized vascular endothelial growth factor receptor-2 (VEGFR2) and "membrane rafts" plays key role in angiogenesis. However, our knowledge about the trafficking pathways involved in the maintenance of VEGFR2 and raft component localization to the cell surface is limited. By studying and understanding the trafficking of angiogenesis-regulatory molecules, we may identify a novel target for therapy.