Role of End Binding 3 in Mechanism of vascular permeability

肺血管通透性的增加导致富含蛋白质的组织水肿，这是成人肺水肿的一个重要特征。 呼吸窘迫综合征微管（MT）细胞骨架在细胞增殖机制中的作用 内皮渗透性还不清楚。众所周知，MT会进行重组，以应对亲 炎症介质，并因此可能有助于增加内皮通透性的机制。的 拟议的研究将解决末端结合蛋白-3（EB 3），一种MT加末端结合因子，在 调节增加的肺血管通透性。我们将检验以下假设：（i）EB 3是一种主要成分 血管内皮（VE）-钙粘蛋白粘附复合物和MT细胞骨架之间的串扰， (ii)EB 3介导的MT动力学控制对维持肺微血管基础通透性至关重要 以及由炎症介质引起的渗透性增加。这些研究将解决以下问题 具体目的：（1）VE-钙粘蛋白介导的信号转导在EB 3磷酸化机制中的作用， MT生长的抑制，从而“由外向内”信号传导在建立基础免疫应答中的作用。 肺内皮细胞的通透性;和（2）EB 3在调节Ca 2+信号传导中的关键作用， 介导内皮通透性增加和肺水肿的发展。我们期望 通过了解VE-钙粘蛋白粘附如何发出EB 3磷酸化信号，以及EB 3如何由此促进细胞凋亡， 屏障通透性增加将为肺液调节异常的机制提供新的见解 体内平衡我们将利用最先进的技术，包括活细胞成像，突变体的表达， 构建、基因转移和肺部炎症的小鼠模型以实现特定目的。

Increases in lung vascular permeability result in protein-rich tissue edema, an important feature of adult respiratory distress syndrome. The role of the microtubule (MT) cytoskeleton in the mechanism of increased endothelial permeability is not well understood. MTs are known to undergo re-organization in response to pro- inflammatory mediators, and may thus contribute to the mechanism of increased endothelial permeability. The proposed studies will address the central role of End Binding protein-3 (EB3), a MT plus-end binding factor, in regulating increased lung vascular permeability. We will test the hypotheses that (i) EB3 is a major component of cross-talk between Vascular Endothelial (VE)-cadherin adhesion complexes and the MT cytoskeleton and (ii) EB3-mediated control of MT dynamics is critical for maintenance of basal permeability of lung microvessels and for permeability increase caused by inflammatory mediators. These studies will address the following Specific Aims: (1) role of VE-cadherin-mediated signaling in the mechanism of EB3 phosphorylation and inhibition of MT growth and, thereby the role of "outside-in" signaling in establishing basal permeability of lung endothelia; and (2) critical role of EB3 in regulating Ca2+ signaling, thus in mediating increased endothelial permeability and development of lung edema. It is our expectation that by understanding how VE-cadherin adhesion signals EB3 phosphorylation and how EB3 thereby elicits the barrier permeability increase will provide novel insights into the mechanisms of dysregulation of lung fluid homeostasis. We will exploit state of the art technologies including live cell imaging, expression of mutant constructs, gene transfer, and murine models of lung inflammation to accomplish the specific aims.