Evolution and resolution of ARDS molecular phenotypes

抽象的。急性呼吸窘迫综合征(ARDS)与高死亡率、发病率和 医疗费用(Bellani 2016)。数十种治疗ARDS的候选药物已在临床前被确定 在随机对照试验(RCT)中，没有一个模型能持续降低死亡率。这一惨淡的记录是 可能部分是由ARDS定义中包含的异质生物学驱动的(Rubenfeld，2015)。 血浆生物标记物和临床变量的非监督聚类最近确定了两个分子 ARDS的表型(Calfee 2014)，可能会在未来的随机对照试验中实现预测性浓缩。不确定关于 区分这两种表型的关键生物学机制仍然是至关重要的 知识鸿沟。这项建议的总体目标是招募患者到一个既定的队列 机械通气患者和识别ARDS分子肺损伤的不同机制 表型。这一建议的中心假设是ARDS表型由不同的 失调的通路，导致不同的临床轨迹和治疗反应。在目标1中，我将使用 单细胞RNA测序研究气管抽吸物并建立大鼠肺细胞信号传导模型 每种分子表型。I假设高炎症性ARDS与1型T细胞增多有关 巨噬细胞的极化和对干扰素的反应减弱。在《目标2》中，我将使用元翻译 对不同表型的气管吸气微生物组进行测序，以确定其差异。我假设 TA转译酶在每个表型中都有不同的微生物群落组成，这将是 以低炎症表型中肠道细菌负荷增加为特征，并增加 真菌在高炎症表型中的负担。在目标3中，我将收集纵向气管吸气和 血浆样本以研究在每一种情况下促炎、促消退和促纤维化途径的演变 ARDS表型。我假设ARDS的表型有不同的炎症和修复轨迹 机械通气组第一周的路径。我将解决所需知识的一个严重差距 开发针对表型的精确治疗方法。这个K23奖项是由卡罗琳·卡尔菲博士赞助的 经验丰富的ARDS研究人员，他的团队开创了ARDS分子表型分析的先河。 斯蒂芬妮·克里斯滕森是一位计算生物学家，在呼吸道疾病的转录组学方面拥有专长。 他们的指导和在K23的研究和培训计划将支持我继续职业发展 并允许我学习成为一名独立调查员所需的基本技能，包括高级 研究队列的计算分析、流行病学方法和管理。开发这些功能 要实现我的长期目标，即理解区分不同的机械路径，技能是必不可少的 ARDS表型以确定新的潜在治疗方法。提议的目标为R01奠定了基础 建议研究ARDS表型中肺部和全身炎症的相互作用。

ABSTRACT. The acute respiratory distress syndrome (ARDS) is associated with high mortality, morbidity, and health care costs (Bellani 2016). Dozens of candidate drugs for ARDS have been identified in preclinical models, but none consistently reduced mortality in randomized controlled trials (RCTs). This dismal record is likely driven in part by the heterogenous biology encompassed within the definition of ARDS (Rubenfeld 2015). Unsupervised clustering of plasma biomarkers and clinical variables recently identified two molecular phenotypes of ARDS (Calfee 2014) which may enable predictive enrichment in future RCTs. Uncertainty about the key biologic mechanisms that distinguish these two phenotypes from each other remains a critical knowledge gap. The overall objective of this proposal is to recruit patients to an established cohort of mechanically ventilated patients and identify distinct mechanisms of lung injury in ARDS molecular phenotypes. The central hypothesis of this proposal is that ARDS phenotypes are driven by different dysregulated pathways that result in distinct clinical trajectories and responses to treatment. In Aim 1, I will use single cell RNA sequencing to study tracheal aspirates and develop a model of cell signaling in the lung of each molecular phenotype. I hypothesize hyperinflammatory ARDS is associated with increased Type 1 T-cell polarization and a diminished response to interferons in macrophages. In Aim 2, I will use metatranscriptomic sequencing to characterize differences in the tracheal aspirate microbiome in each phenotype. I hypothesize TA metatranscriptomes will have distinct microbial community composition in each phenotype, which will be characterized by increased burden of enteric bacteria in the hypoinflammatory phenotype and an increased burden of fungi in the hyperinflammatory phenotype. In Aim 3, I will collect longitudinal tracheal aspirate and plasma samples to study the evolution of pro-inflammatory, pro-resolution, and pro-fibrotic pathways in each ARDS phenotype. I hypothesize ARDS phenotypes have distinct trajectories of inflammation and repair pathways in the first week of mechanical ventilation. I will address a critical gap in knowledge required to develop phenotype-specific precision treatments. This K23 award is sponsored by Dr. Carolyn Calfee, an experienced ARDS researcher whose group has pioneered analyses of ARDS molecular phenotypes, and Dr. Stephanie Christenson, a computational biologist with expertise in the transcriptomics of airway diseases. Their mentorship and the research and training plan in this K23 will support my continued career development and allow me to learn essential skills I require to be an independent investigator, including advanced computational analyses, epidemiological methods, and management of a research cohort. Developing these skills will be essential to achieve my long-term goal of understanding the mechanistic pathways distinguishing ARDS phenotypes to identify novel potential therapies. The proposed aims lay the foundation for a R01 proposal to study the interaction of pulmonary and systemic inflammation in ARDS phenotypes.