Regulation of endothelial cell junctions by VEGF and angiopoietin

VEGF 和血管生成素对内皮细胞连接的调节

• 批准号: 8827843
• 负责人: Arie Horowitz
• 金额: $ 39.03万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2015-10-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8827843
• 关键词: Accounting; Actins; Address; Adherens Junction; Angiopoietin-1; Angiopoietins; Atherosclerosis; Binding Proteins; Blood Vessels; Brain; Cells; Code; Cytoplasm; Data; Dependence; Diabetes Mellitus; Disease; Disease Outcome; Drug Targeting; Edema; Endothelial Cells; Extravasation; Eye diseases; Foundations; Genes; Genetic; Glioblastoma; Goals; Guanine; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate Phosphohydrolases; Health; Heart Diseases; Integral Membrane Protein; Intercellular Junctions; Intracranial Hypertension; Knowledge; Lead; Ligands; Macular degeneration; Maintenance; Malignant Neoplasms; Malignant neoplasm of brain; Mediating; Membrane Protein Traffic; Microfilaments; Modeling; Molecular; Morbidity - disease rate; Mus; Myocardial Ischemia; Outcome; Pathology; Pathway interactions; Pattern; Permeability; Pharmaceutical Preparations; Pharmacotherapy; Process; Property; Proteins; Public Health; Receptor Protein-Tyrosine Kinases; Recruitment Activity; Regulation; Research; Rheumatoid Arthritis; Role; Scheme; Signal Pathway; Signal Transduction; Solid; Stroke; TIE-2 Receptor; Tertiary Protein Structure; Testing; Tight Junctions; Vascular Endothelial Growth Factors; Vascular Permeabilities; Vascular System; Zebrafish; angiogenesis; base; cell motility; cytokine; design; effective therapy; improved; in vivo; innovation; loss of function; mouse model; novel; novel strategies; prevent; protein function; response; stem; therapeutic target; trafficking

DESCRIPTION (provided by applicant): A crucial gap in the understanding of endothelial cell (EC) junction maintenance is the absence of a molecular mechanism to explain how angiopoietin-1 (Ang1) and its receptor, Tie2, stabilize the junctions. Loss of junction integrity i implicated in numerous diseases, including cancer, stroke, diabetes, rheumatoid arthritis, atherosclerosis, cardiac ischemia, and macular degeneration. In such pathologies, vascular endothelial growth factor (VEGF) has a potent disruptive effect on cell junctions and undermines vessel integrity. In contrast, angiopoietin-1 (Ang1) opposes the effect of VEGF and maintains junction integrity. Similar to Ang1, the formin protein mDia has a stabilizing effect on cell junctions, due to its maintenance of the cortical actin ring. We have obtained exciting preliminary results, which support the premise that mDia is an Ang1 effector. Based on these results, our proposal is expected to provide the first detailed account of the antagonistic effects of VEGF and Ang1 on cell junctions. Our central hypothesis is that VEGF and Ang1 regulate EC junctions by determining the spatial pattern of the activities of mDia and Syx (a RhoA-specific guanine exchange factor upstream of mDia) via membrane traffic. We will address this hypothesis by pursuing three specific aims: (1) determining how Ang1 recruits Syx to EC junctions; (2) determining the role of mDia trafficking in Ang1 and VEGF signaling; (3) determining how Syx and mDia regulate Ang1 signaling in a murine model of glioblastoma. To this end, we will use mouse and zebrafish loss-of-function models of several of the genes relevant to these pathways. The potential contribution of this study is significant because it will advance the field conceptually by integrating VEGF and Ang1 signaling into a coherent regulatory mechanism of vessel permeability. This will have a lasting effect on the general understanding of cell-cell junctions. A consequence of the poor knowledge of Ang1 regulation of cell junctions is the scarcity of drugs to target the Ang1 signaling pathway. This putative pathway, leading from Ang1/Tie2 to mDia and to the stabilization of endothelial cell junctions, implicates several proteins that have not been considered before as drug targets. The elucidation of this signaling pathway will provide, therefore, a solid foundation for the design of new therapies to prevent vessel leakage in pathological conditions. As a principal outcome, we will define key checkpoints that will allow us to selectively control VEGF vs. Ang1/Tie2 mediated angiogenesis. These features constitute the potential translational significance of our proposed research. The proposed research is innovative in that it will reveal a novel signaling pathway to explain how Ang1 stabilizes EC junctions, and will incorporate membrane traffic as a novel component of angiogenesis.

描述（由申请人提供）：对内皮细胞（EC）连接维持的理解的一个关键差距是缺乏解释血管生成素-1（Ang1）及其受体 Tie2 如何稳定连接的分子机制。连接完整性的丧失与许多疾病有关，包括癌症、中风、糖尿病、类风湿性关节炎、动脉粥样硬化、心肌缺血和黄斑变性。在此类病理中，血管内皮生长因子 (VEGF) 对细胞连接具有强大的破坏作用，并破坏血管的完整性。相反，血管生成素-1 (Ang1) 可对抗 VEGF 的作用并维持连接完整性。与 Ang1 类似，formin 蛋白 mDia 对细胞连接具有稳定作用，因为它能维持皮质肌动蛋白环。我们已经获得了令人兴奋的初步结果，这支持了 mDia 是 Ang1 效应器的前提。基于这些结果，我们的提案预计将首次详细说明拮抗作用 VEGF 和 Ang1 在细胞连接处的表达。我们的中心假设是 VEGF 和 Ang1 通过膜交通确定 mDia 和 Syx（mDia 上游的 RhoA 特异性鸟嘌呤交换因子）活动的空间模式来调节 EC 连接。我们将通过追求三个具体目标来解决这一假设：（1）确定 Ang1 如何将 Syx 招募到 EC 连接处； (2)确定mDia运输在Ang1和VEGF信号传导中的作用； (3) 确定 Syx 和 mDia 如何在胶质母细胞瘤小鼠模型中调节 Ang1 信号传导。为此，我们将使用与这些途径相关的几个基因的小鼠和斑马鱼功能丧失模型。这项研究的潜在贡献是重大的，因为它将 通过将 VEGF 和 Ang1 信号转导整合到血管通透性的连贯调节机制中，从概念上推进了该领域的发展。这将对细胞与细胞连接的一般理解产生持久影响。由于对 Ang1 对细胞连接的调节了解甚少，导致缺乏针对 Ang1 信号通路的药物。这一假定的途径从 Ang1/Tie2 通向 mDia 并稳定内皮细胞连接，涉及几种以前未被认为是药物靶点的蛋白质。因此，对该信号通路的阐明将为设计提供坚实的基础。 防止病理条件下血管渗漏的新疗法。作为主要成果，我们将定义关键检查点，使我们能够选择性地控制 VEGF 与 Ang1/Tie2 介导的血管生成。这些特征构成了我们提出的研究的潜在转化意义。拟议的研究具有创新性，因为它将揭示一种新的信号传导途径来解释 Ang1 如何稳定 EC 连接，并将膜交通纳入血管生成的新组成部分。