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 研究的目的是解决促炎症的关键信号通路 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) 牢固粘附。 我们假设凝血酶通过以下方式诱导 NF-kB 激活和 ICAM-1 表达： 特定异源三聚体 G 蛋白与蛋白酶的相互作用 激活受体-1 (PAR-1) 和由此产生的激活 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性表达 这种机制导致肺中性粒细胞隔离和中性粒细胞依赖性肺血管 损伤和组织水肿。获得对分子发病机制的新见解 PMN 依赖性肺血管损伤的研究，该提案将重点关注特定的 凝血酶激活 PAR-1 对细胞内信号传导的影响 进而调节内皮细胞中 NF-kB 的激活和 ICAM-1 的表达 细胞。该提案的具体目标是： 1. 确定 Galpha-q 在功能上与 PAR-1 偶联，介导凝血酶诱导 NF-kB 激活和 ICAM-1 表达以及由此产生的内皮粘附性 和 PMN 跨内皮屏障迁移。 2.确定PI3的作用 激酶和转导 PAR-1 激活的下游信号事件 介导 NF-kB 激活和 ICAM-1 表达的信号。 3.解决 Galpha-i 在功能上与 PAR-1 耦合，在预防 凝血酶诱导的 NF-kB 激活和内皮细胞中 ICAM-1 的表达。 这些研究将使用人类血管内皮细胞的原代培养物 鼠标模型。我们将使用药物和重组腺病毒 编码信号分子的激活或显性失活形式 调节内皮细胞的基因表达。最后，我们还将使用 PAR-1 和 PI3 激酶敲除小鼠模型，以解决它们在体内作用 凝血酶诱导肺 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 内皮粘附性的调节并提供未来方向 通过药理学和基因操作干扰不适当的 PMN 隔离和 PMN 介导的肺损伤。