Role of heme and PGP matrikines in lung inflammation

血红素和 PGP 基质素在肺部炎症中的作用

• 批准号: 10468254
• 负责人: AMIT GAGGAR
• 金额: $ 54.72万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10468254
• 关键词: Acute; Acute Lung Injury; Address; Attenuated; Binding; Biochemical; Biological Assay; Blood Circulation; C57BL/6 Mouse; Cause of Death; Clinical; Collagen; Critical Illness; Data; Dependence; Disease; Endothelium; Epithelial; Epithelial Cells; Exposure to; Extracellular Matrix; Female; Functional disorder; Generations; Glycine; Goals; Heme; Hemopexin; Human; IL8RB gene; In Vitro; Individual; Inflammation; Inflammation Mediators; Inflammatory; Link; Liquid substance; Lung; Mass Spectrum Analysis; Measures; Mediating; Mediator of activation protein; Modeling; Molecular; Morbidity - disease rate; Mus; Organ; Outcome; Pathogenesis; Pathway interactions; Patients; Peptide Hydrolases; Peptides; Permeability; Pharmacology; Phase II Clinical Trials; Plasma; Proline; Protease Inhibitor; Proteins; Public Health; Pulmonary Inflammation; Reactive Oxygen Species; Role; Sampling; Secondary to; Sepsis; Septic Shock; Severity of illness; Signal Transduction; Signaling Protein; Testing; Therapeutic; airway epithelium; cadherin 5; cecal ligation puncture; endopeptidase A; exosome; extracellular; heme a; human model; improved; in vivo; in vivo evaluation; inhibitor; insight; lung development; lung injury; lung microvascular endothelial cells; male; monolayer; mortality; mouse model; new therapeutic target; novel; predict clinical outcome; prevent; prolinal; prolyl oligopeptidase; prolyl-glycyl-proline; prolyl-proline; sepsis induced acute lung injury; septic patients; small molecule; therapeutic target

PROJECT SUMMARY: Sepsis-related acute lung injury (ALI), characterized by increased lung permeability and inflammation remains a significant cause of death in critically ill individuals. Several inflammatory mediators and mechanisms underlying increased lung leak have been identified, which while leading to improved therapeutics, have plateaued suggesting as yet undefined mechanisms, and / or interactions between distinct mediators. In this proposal, we build upon our preliminary data showing that proline-glycine-proline (PGP) peptides derived from the matrix protein collagen, are increased in human and murine models of sepsis, and that these matrikines promote lung leak via CXCR2 activation. In this application, we address the following three questions i) What mechanisms regulate PGP formation? We hypothesize that free heme, a newly identified mediator of sepsis pathogenesis, stimulates the release of exosomes containing active prolyl endopeptidase (PE), a protease that catalyzes the terminal step of collagen breakdown to PGP in the extracellular compartment. Preliminary data show scavenging of heme by hemopexin decreases circulating PGP levels in vivo; ii) Does endogenous PGP mediate sepsis induced lung permeability? Preliminary data show that administration of Arg-Thr-Arg (RTR), a peptide that selectively binds and inhibits PGP, prevents lung leak in vitro and vivo; iii) Does PGP associate with severity of disease and ALI in human sepsis? Preliminary data show increases in circulating PGP peptides in human sepsis and demonstrate that this is able to elicit pro-permeability signaling. We propose 3 aims to test our hypothesis that PGP matrikines mediate sepsis-ALI, SA1: Determine the role and mechanisms by which free heme mediates PGP peptide formation. SA2: Determine the role and mechanisms by which PGP mediates sepsis-ALI and SA3: Determine whether plasma levels of free heme, PE-exosomes, and PGP peptides correlate both clinical outcomes and development of lung injury in patients with sepsis. We propose to use a combination of primary human epithelial cells, pulmonary microvascular endothelial cells and the cecal-ligation puncture model of sepsis using C57Bl/6 male and female mice to test our hypothesis, and couple this with biochemical and molecular approaches to measure protease activity, free heme levels, exosomes and PGP peptide levels. Mechanistic insights will be gained using selective inhibitors of heme, PGP and proteases that generate PGP, as well as a novel endothelial targeted CXCR2-/- mouse model generated for the proposed studies. Successful completion of these aims will significantly improve our understanding of mechanisms underlying sepsis-ALI with a specific emphasis on protease containing exosomes and matrikines as new mediators and therapeutic targets in this debilitating disorder.

项目摘要： 败血症相关的急性肺损伤（ALI），其特征是肺部渗透性增加和炎症仍然是 重症患者的重大死亡原因。几种炎症介质和机制 已经确定了增加的肺泄漏，尽管导致治疗疗法改善，但已稳定 暗示尚未定义的机制和 /或不同介体之间的相互作用。在这个建议中，我们 建立在我们的初步数据的基础上，表明脯氨酸 - 甘氨酸 - 丙啉（PGP）肽衍生自基质 蛋白质胶原蛋白在败血症的人和鼠模型中增加，并且这些基金会促进肺 通过CXCR2激活泄漏。在此应用程序中，我们解决以下三个问题i）什么机制 调节PGP形成？我们假设自由血红素是败血症发病机理的新鉴定的介体， 刺激含有活性脯氨酰内肽酶（PE）的外泌体的释放，该蛋白酶催化了 胶原蛋白分解到细胞外室中PGP的末端步骤。初步数据显示清除 血红素的血红素在体内降低了循环的PGP水平； ii）内源性PGP介导败血症 诱导肺部渗透性？初步数据表明，Arg-Thr-Arg（RTR）的给药是一种肽 有选择地结合并抑制PGP，可防止体外和体内肺泄漏。 iii）PGP与严重程度相关 人败血症中的疾病和阿里？初步数据显示，人类败血症中循环的PGP肽的增加 并证明这能够引起促进性信号传导。我们提出3个旨在检验我们的假设的目标 PGP Matrikines介导败血症ALI，SA1：确定游离血红素的作用和机制 介导PGP肽形成。 SA2：确定PGP介导脓毒症-ALI的作用和机制 和SA3：确定游离血红素，PE-诊断和PGP肽的等离子水平是否相关 脓毒症患者的临床结局和肺损伤的发育。我们建议将 原发性人类上皮细胞，肺微血管内皮细胞和Cecal-Rigation穿刺模型 使用C57BL/6雄性和雌性小鼠检验我们的假设的败血症，并将其与生化和 测量蛋白酶活性，自由血红素水平，外泌体和PGP肽水平的分子方法。 机械洞察力将使用血红素，PGP和产生PGP的蛋白酶的选择性抑制剂获得。 以及用于拟议研究的新型内皮靶向CXCR2 - / - 小鼠模型。成功的 这些目标的完成将显着提高我们对败血症基础机制的理解 对含有外泌体和基金的蛋白酶作为新介质和治疗靶标的蛋白酶的特定强调 在这种使人衰弱的疾病中。