Modest supplemental oxygen worsens lung injury in a murine model of sepsis

适度补充氧气会加重脓毒症小鼠模型的肺损伤

• 批准号: 7544295
• 负责人: Neil Raj Aggarwal
• 金额: $ 5.09万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7544295
• 关键词: Acetylcysteine; Acute; Acute Lung Injury; Adult Respiratory Distress Syndrome; Alveolar; Alveolar Cell; Alveolar Macrophages; Amplifiers; Animal Model; Antioxidants; Apoptosis; Attenuated; Automobile Driving; Biological Assay; Body Weight decreased; Cell Count; Cells; Cessation of life; Clinical; Count; Data; Dendritic Cells; Development; Disease; Dose; Environment; Enzymes; Epithelial; Exposure to; Generations; Goals; Healthcare Systems; Histologic; Histology; Hospitalization; Hour; Human; In Vitro; Incubated; Inflammatory; Injury; Ligation; Lipopolysaccharides; Luminol; Lung; Measures; Mediator of activation protein; Modeling; Morbidity - disease rate; Mus; Newborn Respiratory Distress Syndrome; Outcome; Oxidative Stress; Oxygen; Pathologic; Pathway interactions; Pattern; Production; Proteins; Public Health; Puncture procedure; Range; Reactive Oxygen Species; Reporting; Respiratory Mechanics; Risk Factors; Role; Sepsis; Severities; Source; Time; Toxic effect; Variant; Weight; Work; antioxidant therapy; clinically relevant; cytokine; day; dichlorofluorescin; experience; extracellular; improved; in vivo; insight; interstitial; intraperitoneal; lung injury; macrophage; mortality; mouse model; neutrophil; research study; wet lung

DESCRIPTION (provided by applicant): Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with high levels of morbidity and mortality, imposing a substantial burden on the health care system. Sepsis is a frequent cause of ALI making the study of sepsis-induced lung injury crucial. Using systemic lipopolysaccharide (LPS) we observed predominantly interstitial lung injury with a paucity of alveolar neutrophils and damage, dramatically different from the prominent alveolar injury and neutrophil influx seen with direct lung injury. Along the way to understanding the difference between direct and indirect injury in mice, we postulated that 50% oxygen would augment lung injury in mice after systemic insult compared to LPS or 50% oxygen alone. Our injury model consists of LPS followed 12 hrs later by exposure to 50% or 21% oxygen for 60 hrs. At day 3, mice exposed to LPS plus oxygen showed a synergistically increase lung injury, with a prominent alveolar component, compare to other groups. We hypothesize that the addition of 50% oxygen to LPS increases oxidative stress and inflammatory cytokine production, thereby augmenting lung injury, and that injury can be mitigated with antioxidant therapy. We plan to examine aspects of this hypothesis with following 2 aims: 1. To examine potential mechanisms driving the augmentation of lung injury by combined exposure to LPS and supplemental oxygen. Mice exposed to LPS, 50% oxygen, or LPS plus oxygen, will be assessed for mortality, weight loss; BAL cell counts, differentials, total protein, wet lung weight; and histology. In addition, we will measure: intracellular and extracellular ROS generation; lung anti-oxidant enzyme levels; BAL/Lung cytokines; and alveolar cell apoptosis at defined intervals. In vitro, we will incubate naive alveolar macrophages (AMs) and dendritic cells (DCs) with LPS, 50% oxygen, or in combination, and measure ROS production and key inflammatory mediators previously identified. 2. To determine if NAc therapy concurrent with supplemental oxygen abrogates lung injury, and examine potential mechanisms of that effect. NAc or control will be given to groups as in Aim 1, and the effect on injury patterns will be assessed. In addition, we will examine cytokine and anti-oxidant potential pathways indicated by Aim 1 findings, as well as time- and cell-specific ROS and apoptosis activity. Public Health Relevance: Significant injury to the lungs requiring hospitalization and death can occur from systemic illness. We will examine the role of moderate oxygen as a potential amplifier of that injury in an animal model. This work has the potential to improve human outcomes and decrease burden on the health care system from this devastating illness.

描述（由申请人提供）：急性肺损伤（ALI）和急性呼吸窘迫综合征（ARDS）与高发病率和死亡率相关，给医疗保健系统带来沉重负担。脓毒症是 ALI 的常见原因，因此脓毒症引起的肺损伤的研究至关重要。使用全身脂多糖（LPS），我们观察到主要是间质性肺损伤，伴有少量肺泡中性粒细胞和损伤，这与直接肺损伤中观察到的显着肺泡损伤和中性粒细胞流入有显着不同。在了解小鼠直接损伤和间接损伤之间的差异的过程中，我们假设与仅使用 LPS 或 50% 氧气相比，50% 氧气会加重全身损伤后小鼠的肺损伤。我们的损伤模型包括 LPS，12 小时后暴露于 50% 或 21% 氧气 60 小时。在第 3 天，与其他组相比，暴露于 LPS 加氧气的小鼠显示出协同增加的肺损伤，其中肺泡成分明显。我们假设向 LPS 中添加 50% 的氧气会增加氧化应激和炎症细胞因子的产生，从而加剧肺损伤，并且可以通过抗氧化治疗减轻损伤。我们计划通过以下两个目标来检验这一假设的各个方面： 1.检验联合暴露于 LPS 和补充氧气导致肺损伤加剧的潜在机制。将评估暴露于 LPS、50% 氧气或 LPS 加氧气的小鼠的死亡率、体重减轻； BAL 细胞计数、差异、总蛋白、肺湿重；和组织学。此外，我们还将测量：细胞内和细胞外 ROS 的生成；肺抗氧化酶水平； BAL/肺细胞因子；和肺泡细胞凋亡在规定的时间间隔。在体外，我们将用 LPS、50% 氧气或两者的组合孵育幼稚肺泡巨噬细胞 (AM) 和树突状细胞 (DC)，并测量 ROS 产生和先前确定的关键炎症介质。 2. 确定 NAc 治疗与补充氧气同时进行是否可以消除肺损伤，并检查该作用的潜在机制。将按照目标 1 向各组提供 NAc 或对照，并评估对损伤模式的影响。此外，我们将检查 Aim 1 研究结果表明的细胞因子和抗氧化潜在途径，以及时间和细胞特异性 ROS 和细胞凋亡活性。公共卫生相关性：全身性疾病可能会导致严重的肺部损伤，需要住院治疗甚至死亡。我们将在动物模型中研究适度的氧气作为潜在的损伤放大器的作用。这项工作有可能改善人类的健康状况，并减轻这种毁灭性疾病给医疗保健系统带来的负担。