Novel Mechanisms Controlling Endothelial Junctions and Vascular Permeability

控制内皮连接和血管通透性的新机制

• 批准号: 10681680
• 负责人: BARRY M. GUMBINER
• 金额: $ 61万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-15 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10681680
• 关键词: Novel; Mechanisms; Controlling; Endothelial; Junctions

Project Summary The vascular endothelium forms a highly regulated permeability barrier between the blood stream and interstitial tissues. Excessive vascular leakiness contributes to many inflammation related disease processes, including edema, sepsis, acute respiratory distress syndrome (ARDS), ischemic stroke, and hemorrhage. To prevent tissue damage resulting from vascular leakiness during inflammation, there is a need to be able to enhance endothelial barrier function. Intercellular junctions control changes in endothelial paracellular permeability, and Vascular-endothelial cadherin (VE-cadherin, CDH5) is a major regulator of endothelial junctions and paracellular permeability. We will explore a novel hypothesis and approach to understanding its role in permeability regulation, based on our findings of allosteric regulation of other cadherins at the cell surface in response to signaling events. The main hypothesis to be examined is that allosteric regulation of VE- cadherin, in coordination with activities of the actin cytoskeleton, is a key mechanism by which it regulates endothelial permeability in response to a range of vascular factors. We will use two novel activating monoclonal antibodies (mAbs) to VE-cadherin that prevent the increase in endothelial permeability induced by thrombin, VEGF, and TNFa, as major tools to test this hypothesis both in vitro and in vivo and to study the mechanism of regulation. The specific aims are: A. Determine whether VE-cadherin cell surface regulation is a common mechanism for a range of endothelial physiological processes. In vitro experiments will be used to determine whether it is similarly regulated by other key factors, including histamine, angiopoietins, Tie2 receptors, and S1P. Endothelial cells from different microvascular beds will be examined. Collaborative experiments will be done to determine flow and shear forces affect mAb induced barrier function. We will also investigate whether activating mAbs inhibit leukocyte diapedesis or affect endothelial morphogenesis and angiogenesis. B. Elucidate the cellular and biochemical mechanisms underlying VE-cadherin cell surface regulation. We will investigate the structural and biophysical basis of its activation by mAbs and test the roles of the phosphorylation of VE-cadherin and associated catenins in activation. We’ll also explore the relationship between cell surface regulation and endocytosis as well as barrier altering cytoskeletal functions. C. Investigate whether activation of VE-cadherin by mAbs enhances barrier function in vivo in mice in leaky vascular conditions or inflammation. We’ll test the effects of activating mAbs on induced acute induced vascular leak, and leukocyte infiltration. We will also examine their effects on mouse models of inflammatory disease processes involving the vasculature, including sepsis and Inflammatory Bowel Disease. These studies will help us understand regulation of endothelial permeability and develop novel approaches to enhance endothelial barrier function to reduce inflammatory processes and diseases.

项目摘要 血管内皮形成了血液和血流之间高度调节的渗透率 间质组织。 包含水肿，败血症，急性呼吸窘迫综合征（ARDS），缺血性中风和出血 防止炎症期间血管泄漏导致的组织损伤，需要能够 增强内皮屏障函数。 渗透性和血管 - 内皮钙粘蛋白（VE-钙粘蛋白，CDH5）是吸收性的主要调节剂。 连接和细胞的渗透性。 根据我们对细胞中其他钙粘蛋白的变构调节的发现，在渗透率调节中的作用 对信号事件的反应。 钙粘蛋白与肌动蛋白细胞骨架的活动协调，是调节的关键机制 响应一系列血管因素的内皮渗透性。 单克隆抗体（mAb）ve-钙粘着蛋白会增加诱导型诱导性诱导性。 凝血酶，VEGF和TNFA是在体外和研究中测试该假设的主要工具。 调节机制。 用于一系列的实质生理过程的常见机制将用于体外实验 确定它是否受其他关键因素的调节，包括组胺，血管生成素，TIE2 将检查来自不同微血管床的受体和S1P 实验将确定流量和剪切forct mab诱导的屏障功能 研究激活mAB是否抑制白细胞尿道化或影响内皮形态发生和 血管生成。 调节。 在激活中，VE-钙粘着蛋白和相关的蛋白酶的磷酸化。 在细胞表面调节和内吞作用以及改变细胞骨架功能的障碍之间。 C.调查MAB的激活VE-cadherin是否会增强渗漏中小鼠体内的屏障功能 血管含量或违反。 血管泄漏和白细胞浸润。 涉及血管的疾病过程，包括败血症和炎症的肠道疾病 地狱会理解对荷兰渗透性的调节，并开发小说台上的小说台化方法以增强 验证屏障功能可减少炎症过程和疾病。