Rac2 in Pulmonary Microvascular Endothelial Cells

肺微血管内皮细胞中的 Rac2

• 批准号: 7016315
• 负责人: Claire M Doerschuk
• 金额: $ 36.86万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7016315
• 关键词: biological fluid transport; body water; cell adhesion molecules; cellular pathology; confocal scanning microscopy; cytokine; electron microscopy; enzyme activity; free radical oxygen; gene expression; gene mutation; guanosinetriphosphatases; immune response; immunoprecipitation; interferon gamma; laboratory mouse; lung injury; microcirculation; neutrophil; pulmonary edema; respiratory circulation; tissue /cell culture; tumor necrosis factor alpha; vascular endothelium; vascular endothelium permeability

DESCRIPTION (provided by applicant): Rac2 is a member of the Rac family of GTPases commonly expressed by cells of hematopoietic origin. Our recent studies suggest that Rac2 mRNA and protein is expressed by pulmonary microvascular endothelial cells in a granular pattern within the central perinuclear region, that Rac2 regulates the vascular permeability and enhances the barrier function of normal lungs, that Rac2 is required for increases in pulmonary permeability induced by complement activation, and that endothelial Rac2 expression is regulated by TNF-a. The proposed studies will help to better understand the important roles of this GTPase in lung permeability and inflammation by testing the working hypothesis that Rac2 expressed in endothelial cells modulates fluid flux in healthy lungs and increased vascular permeability in endothelial cell injury by regulating vesicular transport and/or integrity of the endothelial cell borders, and that its activity and expression are modulated during the innate immune response. Aim 1 will determine how Rac2 regulates fluid flux in normal lungs. Extravascular lung water will be measured, the rate of albumin accumulation will be compared in Rac2 deficient and wild type mice, which endothelial cells or other lung parenchymal cells express Rac2 will be evaluated, and whether Rac2 modulates fluid fluxes through changes in the junctional complexes or the vesicular transport system will be determined. Aim 2 will determine how Rac2 is activated during endothelial cell injury. The role of ICAM-1 ligation, reactive oxygen species, and/or deposition of C5b-9 complexes (membrane attack complexes) in initiating Rac2 activation in vivo and in vitro will be examined, as well as the intracellular signaling pathways that lead to Rac2 activation. Aim 3 will determine how TNF-a and other cytokines regulate Rac2. Whether TNF-a, IL-1 and interferon-g all have similar effects on endothelial Rac2 production and activation in vivo and in vitro will be assessed, as well as the role of cytokine-induced signaling pathways. Whether endothelial Rac2 is required for cytokine-induced injury in vivo and in vitro will also be determined. These studies will help to understand the role of endothelial cell Rac2 in enhancing the barrier function and in regulating permeability and other aspects of host defense during injury.

描述（由申请人提供）：Rac2是通常由造血源细胞表达的GTP酶Rac家族的成员。我们最近的研究表明，Rac2 mRNA和蛋白由肺微血管内皮细胞在中央核周区域内呈颗粒状表达，Rac2调节血管通透性并增强正常肺的屏障功能，Rac2是增加肺通透性所必需的补体激活诱导，内皮 Rac2 表达受 TNF-a 调节。拟议的研究将有助于更好地了解这种 GTP 酶在肺通透性和炎症中的重要作用，通过测试以下工作假设：内皮细胞中表达的 Rac2 通过调节囊泡运输和/或调节健康肺部的液体流量，并增加内皮细胞损伤中的血管通透性。或内皮细胞边界的完整性，并且其活性和表达在先天免疫反应过程中受到调节。目标 1 将确定 Rac2 如何调节正常肺部的液体流量。将测量血管外肺水，比较 Rac2 缺陷小鼠和野生型小鼠的白蛋白积累率，评估哪些内皮细胞或其他肺实质细胞表达 Rac2，以及 Rac2 是否通过连接复合物的变化来调节液体流量。将确定囊泡运输系统。目标 2 将确定 Rac2 在内皮细胞损伤期间如何被激活。将检查 ICAM-1 连接、活性氧和/或 C5b-9 复合物（膜攻击复合物）沉积在体内和体外启动 Rac2 激活中的作用，以及导致 Rac2 的细胞内信号通路激活。目标 3 将确定 TNF-a 和其他细胞因子如何调节 Rac2。将评估 TNF-a、IL-1 和干扰素-g 在体内和体外是否对内皮 Rac2 产生和激活具有相似的影响，以及细胞因子诱导的信号通路的作用。内皮 Rac2 是否是细胞因子诱导的体内和体外损伤所必需的也将被确定。这些研究将有助于了解内皮细胞 Rac2 在增强屏障功能、调节通透性以及损伤期间宿主防御的其他方面的作用。