Clinical and Proteomic Characterization of Nucleosomes in Pediatric Acute Respiratory Distress Syndrome

项目摘要/摘要 急性呼吸窘迫综合征(ARDS)的特征是急性发作的弥漫性双侧肺 心力衰竭不能完全解释水肿和严重低氧血症。该综合症影响了印度的4.5万名儿童 美国每年，占儿科重症监护机械通气儿童的10% (PICU)，相关死亡率高达30%。感染是儿童ARDS的主要原因， 高达80%的病例发生在感染性肺炎或非肺部脓毒症的环境中。 尽管进行了几次试验，但没有针对ARDS的特定药物疗法，支持性护理仍然存在 治疗的中流砥柱。在儿童中，缺乏治疗方法的不确定性进一步加剧了 管理，因为指南通常是从成人急性呼吸窘迫综合征推断出来的，适用性不确定。然而， 儿科ARDS具有明显的流行病学和预后特征，因此有必要对此进行专门的研究。 人口。最近的证据表明，核小体，DNA/组蛋白复合体释放到 细胞损伤后核染色质降解导致的循环，是全身脓毒症的致病因素 成人中与创伤相关的ARDS。核小体通常位于细胞核内，释放到 循环对多种细胞类型有毒性，提供了一种新的机制，将各种煽动侮辱与 随后的肺损伤。然而，核小体在儿童ARDS中是否致病尚不清楚。这个 这项提案的主要目标是：1)确定核小体水平和 在儿童ARDS队列中的结果；2)通过以下方式确定致病核小体的组成 确定特定的组蛋白和相关的翻译后修饰；3)证明致病性 翻译后修饰和未修饰的组蛋白在体外细胞培养和体内啮齿动物模型中的差异； 培养成为一名成功的儿科肺损伤转化学家所需的技能 流行病学和蛋白质组学方面的培训。拟议的研究充分利用了 费城儿童医院和宾夕法尼亚大学在儿科ARDS中进行队列研究 并进行新的蛋白质组学分析。一支多元化和经验丰富的指导团队，具有基础、 翻译和临床研究已经汇集在一起，通过严格的培训计划提供指导 参与高级流行病学分析和蛋白质组学的研究指导、教学和强化 师徒关系。拟议的研究将确定血浆核小体与儿童ARDS的相关性， 为分离和分析核小体相关蛋白提供了一种新的技术，并改进了我们的 对循环组蛋白致病性的理解。我们将利用这些洞察力来研究新的疗法 对于ARDS，我将获得必要的临床研究和蛋白质组学方面的培训，以成熟为一个 独立的翻译科学家，致力于改善危重儿童的预后。

PROJECT SUMMARY/ABSTRACT Acute respiratory distress syndrome (ARDS) is characterized by acute onset of diffuse, bilateral pulmonary edema and severe hypoxemia not fully explained by cardiac failure. The syndrome affects 45,000 children in the United States annually, representing 10% of mechanically ventilated children in pediatric intensive care units (PICUs), with an associated mortality rate of up to 30%. Infection is the leading cause of pediatric ARDS, with up to 80% of cases occurring in the setting of either infectious pneumonia or non-pulmonary sepsis. There are no specific pharmacological therapies for ARDS despite several trials, and supportive care remains the mainstay of treatment. In children, a lack of therapies is further compounded by uncertainty in management, as guidelines are typically extrapolated from adult ARDS, with uncertain applicability. However, pediatric ARDS possesses a distinct epidemiologic and outcome profile, necessitating studies specific to this population. Recent evidence has implicated nucleosomes, the DNA/histone complexes released into circulation as a result of nuclear chromatin degradation after cellular damage, as pathogenic in systemic sepsis and trauma-associated ARDS in adults. Normally located within the nucleus, nucleosomes released into the circulation are toxic to multiple cell types, offering a novel mechanism linking diverse inciting insults with subsequent lung injury. However, whether nucleosomes are pathogenic in pediatric ARDS is unknown. The broad objectives of this proposal are to 1) determine the association between nucleosome levels and outcomes in a cohort of pediatric ARDS; 2) determine the composition of the pathogenic nucleosomes by identifying specific histones and associated post-translational modifications; 3) demonstrate the pathogenicity of post-translationally modified and unmodified histones in in vitro cell culture and in vivo rodent models; and 4) develop the skills necessary to become a successful translational scientist in pediatric lung injury by focused training in epidemiology and proteomics. The proposed studies leverage existing infrastructure at the Children’s Hospital of Philadelphia and University of Pennsylvania to conduct a cohort study in pediatric ARDS and to perform novel proteomic analyses. A diverse and experienced mentorship team, with expertise in basic, translational, and clinical research, has been assembled to provide guidance through a rigorous training plan involving research conduct, didactics in advanced epidemiological analyses and proteomics, and intensive mentorship. The proposed studies will establish the relevance of plasma nucleosomes in pediatric ARDS, provide a novel technique for isolating and analyzing nucleosome-associated proteins, and improve our understanding of the pathogenicity of circulating histones. We will use these insights to study novel therapies for ARDS, and I will gain the necessary training in clinical research and proteomics to mature into an independent translational scientist working to improve outcomes for critically ill children.