G-protein-induced Signaling of PMN-mediated Lung Injury

G 蛋白诱导的 PMN 介导的肺损伤信号转导

• 批准号: 6786625
• 负责人: ARSHAD RAHMAN
• 金额: $ 27.56万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6786625
• 关键词: G protein; biological signal transduction; cell adhesion molecules; human tissue; laboratory mouse; lung injury; neutrophil; nuclear factor kappa beta; phosphatidylinositol 3 kinase; receptor coupling; receptor expression; thrombin; thrombin receptor; tissue /cell culture; vascular endothelium

DESCRIPTION (provided by applicant): The overall objective of the proposed studies is to address the critical signaling pathways by which pro-inflammatory mediators such as thrombin mediate the expression of adhesion molecule ICAM-1 (CD54) in endothelial cells and thereby induce firm neutrophil (PMN) adhesion. We hypothesize that thrombin induces NF-kB activation and ICAM-1 expression by the interaction of specific heterotrimeric G-proteins with the Proteinase Activated Receptor-1 (PAR-1) and the resultant activation of phosphatidylinositol 3-kinase (PI3 kinase)-dependent signaling pathways. We further postulate that thrombin-induced expression of endothelial adhesivity by this mechanism leads to lung PMN sequestration and PMN-dependent lung vascular injury and tissue edema. To gain new insights into the molecular pathogenesis of PMN-dependent lung vascular injury, this proposal will focus on specific aspects of thrombin activation of PAR-1 on intracellular signaling which in turn regulate the activation of NF-kB and expression of ICAM-1 in endothelial cells. The specific aims of this proposal are to: 1. Determine the role of Galpha-q that is functionally coupled to PAR-1 in mediating thrombin-induced NF-kB activation and ICAM-1 expression, and resultant endothelial adhesivity and PMN migration across endothelial barrier. 2. Determine the role of PI3 kinase and the downstream signaling events in transducing PAR-1-activated signals that mediate NF-kB activation and ICAM-1 expression. 3. Address the role of Galpha-i, which is functionally coupled to PAR-1, in preventing thrombin-induced NF-kB activation and ICAM-1 expression in endothelial cells. These studies will use primary cultures of human vascular endothelial cells and mouse models. We will use pharmacological agents and recombinant adenoviruses encoding activating or dominant negative forms of signaling molecules to modulate the genetic expression of endotheial cells. Finally, we also will use PAR-1 and PI3 kinase knockout mouse models to address their in vivo role in the mechanism of thrombin-induced lung PMN uptake and PMN-dependent lung vascular injury and tissue edema. The information gained will increase our understanding of the regulation of endothelial adhesivity and provide future directions for pharmacological and genetic manipulations to interfere with inappropriate PMN sequestration and PMN-mediated lung injury.

描述（由申请人提供）：拟议的总体目标 研究是为了解决促炎的关键信号通路 诸如凝血酶等介质介导粘附分子ICAM-1的表达 （CD54）在内皮细胞中，从而诱导中性粒细胞（PMN）粘附。 我们假设凝血酶通过 特异性异三聚体G蛋白与蛋白酶的相互作用 活化的受体1（PAR-1）和结果激活 磷脂酰肌醇3-激酶（PI3激酶）依赖性信号通路。我们 进一步假设凝血酶诱导的内皮粘附表达 这种机制导致肺PMN固相和PMN依赖性肺血管 损伤和组织水肿。为了获得对分子发病机理的新见解 该建议将集中在PMN依赖性肺血管损伤中 PAR-1在细胞内信号传导上激活凝血酶的各个方面 转动调节NF-KB的激活和ICAM-1在内皮中的表达 细胞。该提案的具体目的是：1。确定 Galpha-Q在介导凝血酶诱导的中与PAR-1的功能耦合 NF-KB激活和ICAM-1表达，以及由此导致的内皮粘附性 和PMN跨越内皮屏障的迁移。 2。确定PI3的作用 激酶和下游信号传导事件转导PAR-1激活 介导NF-KB激活和ICAM-1表达的信号。 3。地址 Galpha-i的作用在功能上耦合到PAR-1，在防止 凝血酶诱导的内皮细胞中NF-KB激活和ICAM-1表达。 这些研究将使用人血管内皮细胞的原发性培养物和 鼠标模型。我们将使用药理学剂和重组腺病毒 编码信号分子的激活或主要负面形式 调节内托细胞的遗传表达。最后，我们还将使用 PAR-1和PI3激酶基因敲除小鼠模型，以解决它们在体内的作用 凝血酶诱导的肺PMN摄取和PMN依赖性肺血管的机制 损伤和组织水肿。获得的信息将增加我们的理解 调节内皮粘附性，并为未来的方向提供 药理和遗传操作会干扰不适当的PMN 隔离和PMN介导的肺损伤。