Roles of endothelial tensins

摘要 这些研究的目的是了解控制细胞凋亡的信号转导机制。 血管生成是组织生长和发育以及伤口愈合的重要过程 流程.它也发生在疾病中，如癌症、糖尿病性失明和类风湿性关节炎。在这 本课题主要研究血管紧张素信号通路在血管新生中的作用及其机制。的 张力蛋白家族在组织亚细胞结构和介导信号转导中起关键作用， 粘着斑，是连接细胞外基质和细胞骨架的跨膜结构。 张力蛋白的四个成员（张力蛋白1、张力蛋白2、张力蛋白3和张力蛋白）结合到α-整合素的胞质尾部 通过它们的PTB（磷酸酪氨酸结合）结构域，并通过它们的 N-末端区域，允许张力蛋白桥接肌动蛋白细胞骨架与整联蛋白受体。此外，tensins 含有SH 2（Src同源2）结构域，其与酪氨酸磷酸化以及非酪氨酸磷酸化的蛋白相互作用。 磷酸化的蛋白质，并在粘着斑形成信号复合物。我们最近的研究使用基因敲除 小鼠显示缺乏tensin 1会损害内皮细胞中的管形成活性和血管生成过程 在小鼠中，表明紧张素在血管生成中的重要参与。然而，并不是所有紧张素在 细胞活动。我们发现，tensin 1和tensin 2促进内皮细胞迁移，这是内皮细胞增殖的关键步骤。 血管生成，而tensin 3抑制它。 活动？通过使用荧光标记的tensins和活细胞共聚焦显微镜，我们观察到tensins 显示了迁移细胞中不同的时空定位模式。这些发现引导我们调查 tensins在血管生成中的作用及其调控机制。我们假设紧张素调节 血管生成通过其共同和独特的作用，这是由他们的时空定位决定的 和相关分子，在内皮细胞粘附、迁移和血管腔形成中的作用。三 提出了具体目标（目标1），以确定紧张时空局部化的主要控制 目的2：探讨张力蛋白在体外调控血管内皮细胞形成中的作用及机制 目的3.探讨张力蛋白在细胞内的功能及其调控机制。 使用基因敲除小鼠进行血管生成。我们的研究设计是创新的，因为它探讨了新颖和独特的 张力蛋白在内皮细胞中的功能，并采用多学科方法，整合生物化学， 细胞和分子生物学，活细胞荧光显微镜，细胞培养和小鼠模型，以了解 tensins在血管生成中的作用。该项目具有非常高的临床和翻译相关性， 对血管生成相关疾病的治疗应用的新见解。

Abstract The goal of the proposed studies is to understand the signaling transduction mechanism governing angiogenesis, an important process in growth and development of tissues, as well as in wound healing processes. It also occurs in diseases, such as cancer, diabetic blindness, and rheumatoid arthritis. In this project, we focus on the roles and mechanisms of tensin signaling in endothelial cells during angiogenesis. The tensin family plays critical roles in organizing the subcellular structure and mediating signaling transductions at focal adhesions, which are the transmembrane structures linking the extracellular matrix to the cytoskeleton. The four members of tensin (tensin1, tensin2, tensin3, and cten) bind to the cytoplasmic tails of  integrin through their PTB (phosphotyrosine-binding) domains and interact with actin filaments (except cten) via their N-terminal regions, allowing tensins to bridge the actin cytoskeleton to integrin receptors. In addition, tensins contain an SH2 (Src homology 2) domain that interacts with tyrosine-phosphorylated as well as non- phosphorylated proteins and form signaling complexes at focal adhesions. Our recent studies using knockout mice showed that lack of tensin1 impairs tube formation activities in endothelial cells and angiogenic processes in mice, indicating critical involvements of tensins in angiogenesis. However, not all tensins play similar roles in cellular activities. We found that tensin1 and tensin2 promote endothelial cell migration, a critical step during angiogenesis, whereas tensin3 suppresses it. Why highly homologous tensins exert opposite biological activities? By using fluorescent-tagged tensins and live-cell confocal microscopy, we observed that tensins show different spatiotemporal localization patterns in migrating cells. These findings lead us to investigate the roles and regulatory mechanisms of tensins in angiogenesis. We hypothesize that tensins regulate angiogenesis through their common and unique roles, which are dictated by their spatiotemporal localizations and associated molecules, in endothelial cell adhesion, migration, and vascular lumen formation. Three specific aims are proposed to (Aim 1) determine the primary control of spatiotemporal localizations of tensins during in vitro tube formation; (Aim 2) establish the roles and mechanisms of tensins in regulating endothelial cell tube formation; and (Aim 3) investigate the functions and regulatory mechanisms of tensins in angiogenesis using knockout mice. Our research design is innovative because it probes novel and distinct functions of tensins in endothelial cells, and employs a multidisciplinary approach that integrates biochemistry, cell and molecular biology, live-cell fluorescence microscopy, cell culture and mouse models to understand the roles of tensins in angiogenesis. This project has very high clinical and translational relevance that may offer new insights for therapeutic applications to angiogenic related diseases.