Mechanisms of PMN-mediated Lung Inflammation and Injury

PMN 介导的肺部炎症和损伤的机制

• 批准号: 7457947
• 负责人: Asrar B. Malik
• 金额: $ 32.04万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7457947
• 关键词: 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one; Acute; Adaptor Signaling Protein; Address; Adhesions; Cell Adhesion Molecules; Cell surface; Coupled; Edema; Endothelial Cells; Event; Genetic; Inflammatory; Injury; Intercellular adhesion molecule 1; Lung; Lung Inflammation; Mediating; Microvascular Permeability; Molecular; Mus; NADPH Oxidase; NF-kappa B; Oxidants; Pathway interactions; Phosphotransferases; Physiological; Positioning Attribute; Protein Biosynthesis; Role; Signal Pathway; Signal Transduction; Therapeutic; cytokine; early onset; migration; neutrophil; p21 activated kinase; research study; tumor necrosis factor alpha receptor

The overall objective of Project 1 is to address the critical signaling pathways by which the pro-inflammatory cytokine TNFalpha mediates the expression of the adhesion molecule, ICAM-1, in endothelial cells and thereby induces firm neutrophil (PMN) adhesion. As stable and firm ICAM-1-dependent adhesion of PMNs to endothelial cells may require rapid-onset, protein synthesis-independent ICAM-1 expression as well as delayed protein synthesis-dependent ICAM-1 expression, we will explore both the early course of its expression involving cell surface alterations in the constitutively expressed ICAM-1 in endothelial cells and the delayed expression requiring de novo protein synthesis. We will determine 1) the role of intracellular oxidant signaling by the gp91(phox) (Nox2) NADPH oxidase subunit vs. Nox4 in endothelial cells in mediating ICAM-1 expression and PMN adhesion to endothelial cells downstream of activation of specific TNFalpha receptors, 2) the central role of PKCzeta and its adaptor protein p62 in activating oxidant signaling and thereby in signaling NF-kappaB activation and ICAM-1 expression, 3) the role of the kinases, phosphoinositol 3-kinase and Akt, in signaling PKCzeta activation and thereby in inducing NF-kappaB activation and ICAM-1 expression, and 4) the role of the RhoGTPases, RhoA, Rac, and Cdc42, and downstream effector p21-activated kinase, PAK, in oxidant signaling and mediating the early-onset protein synthesis-independent component of ICAM-1 expression and PMN adhesion. Studies in endothelial cells will utilize molecular approaches to dissect the components of the signaling pathways and delineate the specific pathways mediating ICAM-1 expression, and promoting endothelial adhesivity to PMNs. These studies will be coupled to experiments in intact mouse lung in which the role of these signaling pathways will be determined in mice with specific genetic deletions. The lung studies will involve making physiological assessments of PMN sequestration and migration as well as of microvascular permeability and edema formation. With the completion of these studies, we will have a detailed understanding of the specific signaling mechanisms by which TNFalpha induces endothelial cell ICAM-1 expression and mediates inappropriate PMN adhesion and migration across the pulmonary microvessel barrier. Thus, we will be in the position to develop therapeutic strategies to block the identified specific signaling events mediating acute lung inflammatory injury.

项目1的总体目标是解决促炎性细胞因子TNFALPHA介导内皮细胞中粘附分子ICAM-1的表达，从而诱导企业嗜中性粒细胞（PMN）粘附的关键信号通路。由于PMN对内皮细胞的稳定且坚固的ICAM-1依赖性粘附可能需要快速发作，蛋白质合成独立于ICAM-1表达以及延迟的蛋白质合成依赖性ICAM-1表达，我们将探索其在强度表达的ICAM-1表面构成中的表面变化的早期过程，需要在始终构成的构图中均需要延迟的ICAM-1。我们将确定1）GP91（PHOX）（NOX2）NADPH氧化酶亚基与NOX4在介导ICAM-1表达和PMN对内皮细胞的粘附中的内皮细胞中介导的特定TNFALPHA受体激活的内皮细胞中的介导的内皮细胞中的NADPH氧化酶亚基与NOX4中的NADPH氧化酶亚基与NOX4中的作用。 signaling and thereby in signaling NF-kappaB activation and ICAM-1 expression, 3) the role of the kinases, phosphoinositol 3-kinase and Akt, in signaling PKCzeta activation and thereby in inducing NF-kappaB activation and ICAM-1 expression, and 4) the role of the RhoGTPases, RhoA, Rac, and Cdc42, and downstream effector p21-activated激酶，PAK，在ICAM-1表达和PMN粘附的氧化剂信号传导和介导的早期发作蛋白质合成的成分。内皮细胞中的研究将利用分子方法来剖析信号通路的组成部分并描绘 介导ICAM-1表达的特定途径，并促进对PMN的内皮粘附性。这些研究将与完整小鼠肺的实验耦合，在这些小鼠肺中，这些信号传导途径的作用将在具有特定遗传缺失的小鼠中确定。肺研究将涉及对PMN隔离和迁移以及微血管通透性和水肿形成的生理评估。这些研究的完成后，我们将详细了解TNFALPHA诱导内皮细胞ICAM-1表达并介导不适当的PMN粘附和跨肺部微血管屏障的迁移的特定信号传导机制。因此，我们将有能力制定治疗策略，以阻止介导急性肺炎症损伤的确定的特定信号事件。