Focal adhesion kinase regulation of lung vascular permeability and edemagenesis

描述（由申请人提供）：肺血管屏障功能丧失和炎症细胞浸润是急性肺损伤（ALI）的两个主要特征。该项目将研究内皮局灶黏附激酶（FAK）通过抑制细胞内Ca2+升高调节肺血管通透性增加和炎症反应的基本概念。我们将验证FAK诱导靶向Ca2+传感器基质相互作用分子1 （STIM1）的microRNA-150 （miR-150）表达的假设。我们假设通过这种机制下调STIM1对于阻断内皮细胞中的Ca2+信号至关重要，从而防止肺血管屏障和炎症的破坏。为了解决这一假设，我们建立了一种新的他莫昔芬诱导的内皮细胞（EC）特异性FAK敲除（EC-FAK-/-）以及EC- stim1 -/-小鼠模型。我们将解决以下目标：目标1，利用内皮细胞特异性FAK缺失小鼠，确定FAK在调节肺液平衡和调节肺部炎症中的作用；目的2，确定FAK在抑制STIM1活性中的作用，从而阻断Ca2+进入信号，介导肺血管通透性增加和炎症；目的3，确定miR-150作为FAK的基本效应物的作用，该效应物靶向STIM1，从而防止肺血管通透性增加和炎症。这些研究将结合影像学、遗传学和生理学方法，对内皮FAK在调节肺液稳态和炎症中的作用进行全面综合的研究。这些研究的结果将有可能确定针对ALI的新治疗靶点。

DESCRIPTION (provided by applicant): Loss of lung vascular barrier function and inflammatory cell infiltration are two cardinal features of acute lung injury (ALI). The project wil investigate the fundamental concept that endothelial focal adhesion kinase (FAK) modulates the increase in lung vascular permeability and the inflammatory response by suppressing intracellular Ca2+ rise. We will test the hypothesis that FAK induces microRNA-150 (miR-150) expression which targets the Ca2+ sensor, stromal interacting molecule 1 (STIM1). We postulate that STIM1 downregulation by this mechanism is crucial for blocking Ca2+ signaling in endothelial cells and thereby prevents disruption of lung vascular barrier and inflammation. To address this hypothesis, we have generated a novel tamoxifen-inducible endothelial cell (EC)-specific FAK knockout (EC-FAK-/-) as well as EC-STIM1-/- mouse models. We will address the following aims: Aim #1, To define the role of FAK in regulating lung fluid balance and modulating lung inflammation using endothelial cell-specific FAK null mice; Aim #2, To determine the role of FAK in suppressing STIM1 activity and thereby blocking Ca2+ entry signals mediating increased lung vascular permeability and inflammation; and Aim #3, To define the role of miR-150 as an essential effector of FAK that targets STIM1 and thus prevents increased lung vascular permeability and inflammation. These studies will use a combination of imaging, genetic, and physiological approaches to develop a comprehensive and integrated picture of the role of endothelial FAK in regulating lung fluid homeostasis and inflammation. The results of these studies will have the potential of defining novel therapeutic targets directed against ALI. PUBLIC HEALTH RELEVANCE: Acute lung injury (ALI) characterized by plasma leakage, increased white blood cell influx and cytokine generation is a life threatening disease. Although great strides have been made in effectively supporting ALI patients, current treatment strategies have demonstrated limited success in preventing ALI. Therefore the search continues for more effective treatments to reduce the unacceptably high rate of mortality caused by ALI. Proposed studies will investigate the role of endothelial protein, focal adhesion kinase (FAK) in maintaining lung fluid homeostasis and moderating lung inflammatory injury. We hope these studies will offer novel insights and therapeutic targets that we think will lead to the developmen of more effective treatments with improved outcomes for patients suffering from ALI.