Role of Syntaxin 6 Regulated Post-Golgi Trafficking in Angiogenesis

描述(由申请人提供)：Synaxin 6调控的高尔基体后运输在血管生成中的作用指的是从先前存在的血管系统建立新的血管。血管生成功能障碍可导致多种恶性、炎症性和缺血性疾病。新血管的形成涉及多个细胞过程，包括细胞的增殖和迁移，细胞与细胞和细胞与基质的黏附作用，以及管的形态形成。“膜筏”是质膜上富含鞘脂和甾醇的区域。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(VEGFR2)，所有这些都被认为在血管生成中发挥作用。到目前为止，膜筏和相关成分的细胞内运输在血管生成中所起的作用尚不清楚。我们先前已经确定囊泡融合蛋白Synaxin 6(Syn6)在将RAFT相关的脂类和蛋白质输送到质膜(PM)中具有新的作用。我们的长期目标是了解膜筏组件的运输影响细胞运动的机制(S)。这项研究计划的总体目标是确定由内向外运输和向内皮细胞表面输送“膜筏”成分的分子机制，并检查这些过程在血管生成过程中调节细胞运动的重要性。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拥有专业知识，这将使我们能够解决内皮细胞的这些重要问题。在目标1中，我们将使用体外研究来评估在PM中依赖于syn6的膜筏组成的调节如何影响细胞的运动为此，我们将评估焦点黏附相关蛋白的膜域的形成、募集、组织、激活和动力学。在目标2中，我们将进行体外研究，以揭示VEGFR2分泌运输和传递到PM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一般情况下syn6调节的膜支架组件的运输，更具体地说，关于内皮细胞形态发生和血管生成的VEGFR2的功能意义。这些研究的结果将开始揭开Syn6介导的膜运输调节血管生成的机制，并可能为促进或抗血管生成治疗提供新的候选靶点。与公共健康相关的血管生成涉及从原有的血管形成新的血管，在健康和几种疾病中发挥着重要作用。通过细胞表面定位的血管内皮生长因子受体-2(VEGFR2)和“膜筏”传递的信号在血管生成中起着关键作用。然而，我们对维持VEGFR2和RAFT组分定位到细胞表面的运输途径的了解有限。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.