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: 8694252
• 负责人: Arie Horowitz
• 金额: $ 39.63万
• 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 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8694252
• 关键词: Accounting; Actins; Address; Adherens Junction; Angiopoietin-1; Angiopoietins; Atherosclerosis; Binding Proteins; Blood Vessels; Brain; Cardiac; 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; Heart Diseases; Integral Membrane Protein; Intercellular Junctions; Intracranial Hypertension; Ischemia; Knowledge; Lead; Ligands; Macular degeneration; Maintenance; Malignant Neoplasms; Malignant neoplasm of brain; Mediating; Membrane Protein Traffic; Microfilaments; Modeling; Molecular; Morbidity - disease rate; Mus; 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; public health relevance; 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(申请人提供)：在理解内皮细胞(EC)连接维持方面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、心脏缺血和黄斑变性。在这些病理过程中，血管内皮生长因子(VEGF)对细胞连接有很强的破坏作用，并破坏血管的完整性。相反，血管生成素-1(Ang1)与血管内皮生长因子的作用相反，并维持连接的完整性。与Ang1类似，Forin蛋白mdia对细胞连接具有稳定作用，这是因为它维持着皮质肌动蛋白环。我们已经获得了令人兴奋的初步结果，这支持了MDIA是Ang1效应器的假设。基于这些结果，我们的提案有望提供关于对抗效应的第一个详细说明 血管内皮生长因子和血管紧张素转换酶1在细胞连接上的表达。我们的中心假设是，VEGF和Ang1通过膜交通决定mdia和Syx(一种mdia上游的RhoA特异性鸟嘌呤交换因子)活动的空间模式，从而调节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如何招募Syx到EC连接；(2)确定mdia运输在Ang1和VEGF信号转导中的作用；(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。为此，我们将使用与这些通路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信号整合到一个连贯的血管通透性调节机制中，从概念上推动这一领域的发展。这将对对细胞-细胞连接的一般理解产生持久的影响。由于对Ang1对细胞连接的调控知之甚少，导致缺乏针对Ang1信号通路的药物。这条从Ang1/Tie2到MDIA并稳定内皮细胞连接的可能途径，涉及几个以前从未被认为是药物靶点的蛋白质。因此，对这一信号通路的阐明将为设计 防止病理条件下血管渗漏的新疗法。作为一个主要结果，我们将定义关键的检查点，使我们能够选择性地控制VEGF和Ang1/Tie2介导的血管生成。这些特点构成了我们提出的研究的潜在翻译意义。这项拟议的研究具有创新性，因为它将揭示一种新的信号通路来解释Ang1如何稳定EC连接，并将膜交通作为血管生成的一个新组成部分。