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: 7473229
• 负责人: ARSHAD RAHMAN
• 金额: $ 30.8万
• 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 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7473229
• 关键词: 1-Phosphatidylinositol 3-Kinase; Address; Adhesions; Adult Respiratory Distress Syndrome; Air; Binding; Biochemical; Blood Vessels; Cell Adhesion Molecules; Cell surface; Cells; Coagulation Process; Complex; Coupling; Data; Development; Disease; Edema; Endothelial Cells; Event; Family; Functional disorder; Future; G-Protein-Coupled Receptors; G-substrate; GTP-Binding Proteins; Gene Expression; Genetic; Grant; Host Defense; ICAM1 gene; Inflammatory; Injury; Integrins; Intercellular adhesion molecule 1; Knowledge; Leukocytes; Light; Liposomes; Lung; Mediating; Mediator of activation protein; Molecular Biology; Molecular and Cellular Biology; Mus; PAR-1 Receptor; Pathway interactions; Phase; Phosphatidylinositols; Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide; Phosphotransferases; Physiological; Physiology; Play; Protein Isoforms; Protein Kinase C; Protein Overexpression; Protein-Serine-Threonine Kinases; Range; Raptors; Regulation; Research Personnel; Role; Sepsis; Serine Protease; Signal Pathway; Signal Transduction; Sirolimus; Small Interfering RNA; Structure of parenchyma of lung; Surface; Testing; Therapeutic; Thrombin; Tissues; Vascular Endothelium; base; cell growth; defense response; in vivo; interdisciplinary approach; interest; lung injury; lung vascular injury; migration; mutant; neutrophil; novel; programs; receptor; response; trafficking; upstream kinase

DESCRIPTION (provided by applicant): The overall objective of the proposed studies in this renewal application is to define the mechanisms by which the procoagulant thrombin, a serine protease released during clotting initiated by sepsis or vascular injury, regulates the expression of adhesion molecule, ICAM-1, in endothelial cells, and thereby endothelial adhesivity toward neutrophil (PMN). In the last grant cycle, we showed that PKC(, PI3 kinase, and the downstream target Akt mediate thrombin-induced IKK/NF-(B activation and ICAM-1 expression in endothelial cells. We now have evidence that thrombin-induced IKK/NF-(B activation and ICAM-1 expression are tightly regulated through the functional coupling of PKC( and PI3 kinase to the mammalian target of rapamycin (mTOR). Our data show that mTOR down-regulates thrombin-induced ICAM-1 expression in endothelial cells by controlling a delayed and transient activation of NF-(B. In light of these findings, we hypothesize that thrombin activates mTOR complexes via PKC(- and PI3 kinase/Akt-dependent pathways and that activated mTOR complexes in turn down-regulate IKK/NF-(B activation and ICAM-1 expression in endothelial cells. We further postulate that loss of mTOR-mediated inhibition of thrombin- induced endothelial adhesivity leads to marked exacerbation in lung PMN sequestration and PMN-dependent lung vascular injury and tissue edema. We will address this hypothesis by completion of the following specific aims. Aim 1: Determine the role of mTOR complexes, mTOR-raptor and mTOR-rictor, in modulating thrombin-induced IKK/NF-(B activation, ICAM-1 expression, endothelial adhesivity, and PMN migration across endothelial barrier. Aim 2: Determine the role of PKC( in signaling thrombin-induced activation of mTOR complexes and in thereby modulating IKK/NF-(B activation, ICAM-1 expression, and PMN migration across endothelial barrier. Aim 3: Determine the role of PI3 kinase/Akt in mediating thrombin-induced activation of mTOR complexes, and in thereby modulating NF-(B activation, ICAM-1 expression, and PMN migration across endothelial barrier. Studies will utilize multidisciplinary approaches ranging from biochemical, cellular, and molecular biology to lung physiology to identify the critical inhibitory pathways that are integrated with the stimulatory pathways but in a temporally divergent fashion to tightly regulate ICAM-1 expression induced by thrombin. With the knowledge gained, we believe that it will be possible to block PMN-mediated lung vascular injury by promoting the specific inhibitory signaling events controlling ICAM-1 expression associated with intravascular coagulation. These studies may provide future directions for development of therapeutic strategies for inflammatory disease states such as Acute Respiratory Distress Syndrome (ARDS).

描述（由申请人提供）：本次更新申请中拟议研究的总体目标是确定促凝血酶（脓毒症或血管损伤引发的凝血过程中释放的一种丝氨酸蛋白酶）调节粘附分子 ICAM 表达的机制。 -1，在内皮细胞中，从而内皮细胞对中性粒细胞（PMN）的粘附力。在上一个资助周期中，我们证明 PKC(、PI3 激酶和下游靶标 Akt 介导凝血酶诱导的 IKK/NF-(B 在内皮细胞中的激活和 ICAM-1 表达。我们现在有证据表明凝血酶诱导的 IKK/ NF-(B 激活和 ICAM-1 表达通过 PKC( 和 PI3 激酶与哺乳动物雷帕霉素靶点 (mTOR) 的功能耦合受到严格调节。我们的数据表明mTOR 通过控制 NF-(B) 的延迟和瞬时激活，下调凝血酶诱导的内皮细胞中 ICAM-1 的表达。根据这些发现，我们假设凝血酶通过 PKC(- 和 PI3 激酶/Akt-) 激活 mTOR 复合物依赖性途径，并且激活的 mTOR 复合物反过来下调内皮细胞中 IKK/NF-(B 的激活和 ICAM-1 的表达。我们进一步假设这种损失mTOR 介导的对凝血酶诱导的内皮粘附性的抑制导致肺 PMN 隔离和 PMN 依赖性肺血管损伤和组织水肿显着恶化。我们将通过完成以下具体目标来解决这一假设。目标 1：确定 mTOR 复合物、mTOR-raptor 和 mTOR-rictor 在调节凝血酶诱导的 IKK/NF-(B 激活、ICAM-1 表达、内皮粘附性和 PMN 跨内皮屏障迁移中的作用。目标 2：确定PKC( 在信号传导凝血酶诱导的 mTOR 复合物激活中的作用，从而调节 IKK/NF-(B 激活、ICAM-1 表达，目标 3：确定 PI3 激酶/Akt 在介导凝血酶诱导的 mTOR 复合物激活中的作用，从而调节 NF-(B 激活、ICAM-1 表达和 PMN 跨内皮屏障迁移。研究将利用从生物化学、细胞和分子生物学到肺生理学的多学科方法来确定与刺激途径整合但暂时的关键抑制途径。根据所获得的知识，我们相信通过促进控制与血管内凝血相关的 ICAM-1 表达的特定抑制信号事件来阻断 PMN 介导的肺血管损伤是可能的。这些研究可能为急性呼吸窘迫综合征（ARDS）等炎症性疾病治疗策略的开发提供未来方向。