Hemoglobin in ARDS: a novel mediator of aveolar epithelial cell dysfunction

ARDS 中的血红蛋白：肺泡上皮细胞功能障碍的新型介质

基本信息

批准号：
9236215
负责人：
Julie Anne Bastarache
金额：
$ 40.98万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2020-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9236215
关键词：
Acetaminophen Actins Acute Lung Injury Acute Renal Failure with Renal Papillary Necrosis Acute respiratory failure Address Adult Respiratory Distress Syndrome Advanced Glycosylation End Products Affect Albumins Alveolar American Animal Model Animals Attenuated Blood capillaries Cell Culture Techniques Cell Separation Cell model Cells Chemistry Clinical Clinical Trials Complement Control Groups Critical Illness Cytoskeleton Data Disease Edema Electrical Resistance Electron Spin Resonance Spectroscopy Environment Epithelial Epithelial Cells Epithelium Erythrocytes Exposure to F2-Isoprostanes Functional disorder Future Gases Generations Goals Hemeproteins Hemoglobin Hemorrhage Human Imaging Techniques Impairment Injury Iron Life Lipid Peroxidation Lipid Peroxides Liquid substance Lung Measures Mechanical ventilation Mediating Mediator of activation protein Methemoglobin Methods Mitochondria Modeling Molecular Morbidity - disease rate Mus Outcome Oxidants Oxidation-Reduction Oxidative Stress Oxides PARP9 gene Pathogenicity Patients Permeability Peroxidases Plasma Proteins Porphyrins Pre-Clinical Model Proteins Pulmonary Edema Reactive Oxygen Species Reducing Agents Research Personnel Resources Role Sampling Sepsis Severities Supportive care Testing Therapeutic Effect Tight Junctions United States Ventilator Ventilator-induced lung injury Work capillary cell injury clinically relevant clinically significant improved in vivo imaging inhibitor/antagonist innovation lung injury monolayer mortality multidisciplinary new therapeutic target novel novel therapeutics oxidation public health relevance receptor targeted treatment therapeutic evaluation

项目摘要

DESCRIPTION (provided by applicant): ARDS is a major cause of morbidity and mortality in the United States. There are no specific therapies for ARDS other than protective mechanical ventilation and conservative fluid management and mortality remains high at 30-50%. Thus, there is a critical need for specific therapies that target fundamental mechanisms of ARDS. Increased lung epithelial permeability is a pathophysiologic hallmark of ARDS and is manifest clinically by pulmonary edema, impaired gas exchange and acute respiratory failure. We have identified cell free hemoglobin as a novel mediator of increased epithelial permeability in ARDS. Our preliminary data show that airspace levels of cell-free hemoglobin are high in ARDS and are associated with increased lung permeability and poor clinical outcomes. Furthermore, it is the Ferryl oxidized form of hemoglobin that is elevated in the airspaces in ARDS. In a clinical trial in severe sepsis, the leading cause of ARDS, treatment with an inhibitor of Ferryl hemoglobin, acetaminophen, decreased lipid peroxidation and attenuated acute kidney injury. In cultured lung epithelial cells, hemoglobin treatment induces epithelial barrier permeability through cellular and mitochondrial reactive oxygen species generation. Furthermore, intratracheal administration of cell-free hemoglobin to the lungs of mice leads to generation of oxidized Ferryl hemoglobin and increased lung alveolar capillary barrier permeability. These findings support the overall hypothesis for the proposed studies, that formation of Ferryl-Hgb in the airspace in ARDS causes alveolar epithelial cell oxidative stress and increased epithelial permeability, contributing to the pathophysiology of ARDS. To test this hypothesis I have assembled a cross-disciplinary team of co-Investigators and consultants with expertise in clinical ARDS (Ware), Hgb redox chemistry (Roberts), primary alveolar epithelial cell isolation and culture (Guttentag), mitochondrial oxidative stress (Dikalov), human models of ARDS (Matthay) and advanced in vivo imaging techniques (West) whose expertise complements my own in cellular models of epithelial permeability and animal models of ARDS. We will utilize clinical samples of pulmonary edema fluid already collected from patients with ARDS and hydrostatic pulmonary edema along with mouse and epithelial cell culture studies to show that levels of Ferryl hemoglobin in the airspace are increased in human ARDS and cause increased lung epithelial permeability in mice and cultured epithelial cells (Aim 1). We will define the cellular and molecular mechanism of hemoglobin induced increases in epithelial permeability and cellular and mitochondrial oxidative stress in the epithelium (Aim 2). Finally we will test a therapy targeted at Ferryl hemoglobin (acetaminophen) in cell culture, in a clinically relevant model of ventilator induced lung injury in mice and in an isolated perfused human lung model (Aim 3). This proposal is highly innovative and addresses a clinically significant problem. Results from these studies will greatly advance our understanding of the mechanisms of lung epithelial permeability in acute lung injury and will pave the way for future novel targeted therapeutics in ARDS.

描述（由申请人提供）：ARDS 是美国发病和死亡的主要原因，除了保护性机械通气和保守液体管理外，没有针对 ARDS 的具体治疗方法，因此死亡率仍然很高，高达 30-50%。迫切需要针对 ARDS 基本机制的特异性治疗。肺上皮通透性增加是 ARDS 的病理生理学标志，临床上表现为肺水肿、气体交换受损和急性呼吸衰竭。我们已经确定无细胞血红蛋白是 ARDS 中上皮通透性增加的一种新介质。我们的初步数据表明，ARDS 中空腔中的无细胞血红蛋白水平较高，并且与肺通透性增加和不良临床结果相关。在急性呼吸窘迫综合征 (ARDS) 患者气腔中升高的铁基氧化形式的血红蛋白在一项针对严重脓毒症（ARDS 的主要原因）的临床试验中，使用铁基抑制剂进行治疗。在培养的肺上皮细胞中，血红蛋白、对乙酰氨基酚可减少脂质过氧化并减轻急性肾损伤。此外，气管内给予小鼠肺部无细胞血红蛋白可诱导上皮屏障通透性。氧化铁血红蛋白的产生和肺泡毛细血管屏障通透性增加这些发现支持了总体假设。对于拟议的研究，ARDS 气腔中 Ferryl-Hgb 的形成会导致肺泡上皮细胞氧化应激和上皮通透性增加，从而促进 ARDS 的病理生理学。为了验证这一假设，我组建了一个跨学科的联合研究小组。以及在临床 ARDS (Ware)、Hgb 氧化还原化学 (Roberts)、原代肺泡上皮细胞分离和培养方面具有专业知识的顾问（Guttentag）、线粒体氧化应激（Dikalov）、ARDS 人类模型（Matthay）和先进的体内成像技术（West），其专业知识补充了我在上皮通透性细胞模型和 ARDS 动物模型方面的专业知识。已经从 ARDS 和静水压肺水肿患者收集的肺水肿液以及小鼠和上皮细胞培养研究表明，空气中的铁血红蛋白水平在人类 ARDS 并导致小鼠和培养的上皮细胞的肺上皮通透性增加（目标 1），我们将定义血红蛋白诱导上皮细胞通透性以及细胞和线粒体氧化应激增加的细胞和分子机制（目标 2）。将在呼吸机诱发的小鼠肺损伤的临床相关模型中，在细胞培养物中测试针对铁基血红蛋白（对乙酰氨基酚）的疗法以及在分离的灌注人肺模型中（目标 3），这些研究的结果将极大地促进我们对急性肺损伤中肺上皮通透性机制的理解，并铺平道路。未来针对 ARDS 的新型靶向治疗。