Cigarette smoke and the acute respiratory distress syndrome: mechanisms and the role of alveolar macrophages in priming

项目总结/摘要 急性呼吸窘迫综合征（ARDS），也称为急性肺损伤，是呼吸衰竭的主要来源。 发病率和死亡率，在美国每年有近20万例，死亡率为30- 40%。香烟 吸烟最近被确定为发展为ARDS的危险因素。然而，很少有研究直接 研究了吸烟者易患ARDS的机制，包括肺泡 巨噬细胞是肺泡腔中的主要细胞成分。此外，尚不清楚是否 吸烟者只是容易患上ARDS，或者那些患上ARDS的人是否 与患有ARDS的非吸烟者相比，损伤的关键途径的差异激活。进一步深入了解 吸烟者和非吸烟者的ARDS机制可能确定关键的预防和治疗措施， 没有有效治疗方法的疾病的目标。拟议的项目旨在研究 吸烟者容易发展为ARDS，并确定 吸烟者与非吸烟者的ARDS不同。目的一是研究ARDS的发病机制 通过蛋白质生物标志物和转录组学方法， 确定吸烟者与非吸烟者相比是否有差异激活的损伤途径。我假设 吸烟者会有不同的炎症、氧化应激和损伤的激活途径， 通过蛋白质生物标志物（假设1a）以及增加的促炎和氧化应激来测量 BAL转录组中的基因表达（假设1b）。在目标2中，我将使用人类实验模型 使用吸入性脂多糖（LPS）的急性肺损伤，以研究香烟 吸烟者容易患上ARDS。我假设，在LPS模拟的“第二次打击”的情况下， 来自吸烟者的肺泡巨噬细胞将过度释放炎性细胞因子， 氧化剂/抗氧化剂失衡使吸烟者易患ARDS（假设2）。这些研究将 为吸烟者和非吸烟者的ARDS生物学提供了更多的见解， 为这些亚组患者的新型预防和治疗策略奠定了基础。完成 为了实现这些目标，我组建了一个多学科的指导团队，其专业知识涵盖了相关领域， 需要的学科包括1）卡罗琳卡尔菲博士，我的主要导师和专家在使用翻译 2）Michael Matthay博士，我的共同导师，在使用 研究ARDS发病机制的基础科学实验室方法3）科学顾问普雷斯科特伍德拉夫博士 具有a）基因组学B）人类支气管镜检查研究和c）肺泡巨噬细胞和4） 博士丹尼尔麦考利，一个科学顾问，在安全地使用吸入LPS在人类模型的急性 肺损伤这种指导，沿着旨在解决关键培训差距的培训计划，将使我能够 完成本申请中提出的项目，并为我作为独立调查员的职业生涯做好准备。

PROJECT SUMMARY/ABSTRACT The acute respiratory distress syndrome (ARDS), also known as acute lung injury, is a major source of morbidity and mortality, with nearly 200,000 cases annually in the US and a mortality of 30-40%. Cigarette smoking has recently been identified as a risk factor for developing ARDS. However, few studies have directly examined the mechanisms that predispose smokers to develop ARDS, including the role of alveolar macrophages, the predominant cellular constituent in the alveolar space. Furthermore, it is unknown if cigarette smokers are simply predisposed to develop ARDS, or whether those that do develop ARDS have differential activation of key pathways of injury compared to non-smokers with ARDS. Further insight into the mechanisms of ARDS, both in smokers and non-smokers, may identify key preventative and therapeutic targets for a disease with no effective treatments. The proposed project aims to study the mechanisms through which cigarette smokers are primed to develop ARDS and to determine whether the pathogenesis of ARDS differs in cigarette smokers compared to non-smokers. In Aim 1, I will study the pathogenesis of ARDS via protein biomarker and transcriptomic approaches in an established cohort of critically ill patients to determine if smokers have differentially activated pathways of injury compared to non-smokers. I hypothesize that cigarette smokers will have differentially activated pathways of inflammation, oxidative stress and injury as measured by protein biomarkers (Hypothesis 1a) as well as increased pro-inflammatory and oxidative stress gene-expression in the BAL transcriptome (Hypothesis 1b). In Aim 2, I will use a human experimental model of acute lung injury using inhaled lipopolysaccharide (LPS) to investigate mechanisms through which cigarette smokers are primed to develop ARDS. I hypothesize that in the presence of a “second hit,” modeled by LPS, alveolar macrophages from cigarette smokers will have an exaggerated release of inflammatory cytokines and oxidant/antioxidant imbalance that predisposes smokers to develop ARDS (Hypothesis 2). These studies will provide increased insight into the biology of ARDS in both cigarette smokers and non-smokers, laying the foundation for novel preventative and therapeutic strategies in these subgroups of patients. To accomplish these aims, I have assembled a multidisciplinary mentoring team whose expertise spans the relevant disciplines needed including 1) Dr. Carolyn Calfee, my primary mentor and expert on using translational techniques in human cohorts to study ARDS 2) Dr. Michael Matthay, my co-mentor with expertise in using basic science laboratory approaches to study ARDS pathogenesis 3) Dr. Prescott Woodruff, a scientific advisor with expertise in a) genomics b) human bronchoscopy research studies and c) alveolar macrophages and 4) Dr. Daniel McAuley, a scientific advisor with expertise in safely using inhaled LPS in a human model of acute lung injury. This mentorship, along with a training plan designed to address key training gaps, will allow me to complete the projects proposed in this application and prepare me for a career as an independent investigator.