Biomarker and Metabolomic Investigations in ALI

描述（由申请人提供）：该项目的总体目标是加强我们对急性肺损伤（ALI）发病机制的理解，并扩大生物标志物和代谢组学分析的潜在用途。急性肺损伤（ALI）是一种危及生命的疾病，在美国每年影响20万人，由于没有明确的医学治疗方法，死亡率仍然很高。我们确定哪些高危患者会发展为ALI的能力有限，尽管已经确定了特定的生物标志物，但这些生物标志物如何促进ALI的发病机制仍然存在未解之谜。RAGE是肺泡上皮性肺损伤的标志，与非ALI患者相比，在ALI患者的半壁肺中发现了可溶性RAGE （sRAGE）水平升高。然而，RAGE的激活途径是复杂的，对RAGE进入肺泡空间的机制的解释数据有限。HMGGB1和MMPs参与RAGE通路；然而，没有数据显示所有这些标记物在ALI中同时增加。分析NHLBI生物标本库中的标本使我们能够确认和扩展我们对sRAGE和活性代谢物模式的初步观察。我们建议检验sRAGE、HMGB1、MMP-3和-13作为一个功能单位工作的假设，并且随着时间的推移，ALI患者的水平变化将与死亡率相关。我们将使用代谢组学来扩展这些数据，以显示特定的代谢途径与生物标志物激活和生存状态相关。具体目的是：1)检验半数ALI患者的sRAGE、HMGB1和MMPs与ALI风险对照者相比协调升高的假设；并确定sRAGE、HMGB1和MMP水平随时间持续升高是否与ALI患者的死亡率相关；2)开发与预后相关的ALI高分辨率代谢组学数据库，以便：确定Aim 1中分析的特定代谢组学途径和生物标志物之间的关联，并确定区分ALI幸存者和非幸存者的候选代谢物。为了验证我们的假设，我们将分析从ARDSnet LaSRS试验中获得的NHLBI生物库中的BALF样本，该试验提供了在两个不同时间点收集的BALF。作为对照人群，我们也将从诊断为ALI的有危险的机械通气患者中获得BALF。我们将在BALF中进行HMGB1， MMP-3和-13以及sRAGE的测定。ARDS患者的代谢组学分析将通过高分辨率质谱法进行。长期目标是开发一种可负担得起的方法，可用于预测疾病易感性、诊断、风险分层、治疗反应和预后。

DESCRIPTION (provided by applicant): The overall objective of this project is to enhance our understanding of acute lung injury (ALI) pathogenesis and to expand the potential utility of biomarkers and metabolomic analysis. Acute lung injury (ALI) is a life- threatening disease that affects 200,000 people each year in the US and, because there is no defined medical therapy, mortality rates remain high. Our ability to determine which at-risk patients will progress to ALI i limited, and although specific biomarkers have been identified, there remain unanswered questions about how these biomarkers contribute to ALI pathogenesis. RAGE is a marker of alveolar epithelial lung injury, and elevated levels of soluble RAGE (sRAGE) have been identified in the BALF of patients with ALI when compared to non-ALI patients. However, the RAGE activation pathway is complex and there is limited data explaining the mechanism of sRAGE entry into the alveolar space. HMGGB1 and MMPs have been implicated in the RAGE pathway; however, data showing that all these markers are concomitantly increased in ALI is unavailable. Analyzing specimens from the NHLBI biologic specimen repository allows us to confirm and extend our initial observations about sRAGE and active metabolite patterns. We propose to test the hypothesis that sRAGE, HMGB1 and MMP-3 and -13 work as a functioning unit and changes in levels over time in ALI patients will be associated with mortality. We will extend this data using metabolomics to show that specific metabolic pathways are associated with biomarker activation and survival status. The specific aims are designed to : 1) test the hypothesis that sRAGE, HMGB1 and MMPs are coordinately increased in the BALF of patients with ALI compared to controls at risk for ALI; and determine whether sustained increases in sRAGE, HMGB1 and MMP levels over time are associated with mortality in ALI patients; and 2) develop a high- resolution metabolomic database for ALI linked to outcomes in order to: determine the association between specific metabolomic pathways and biomarkers analyzed in Aim 1, and identify candidate metabolites that differentiate ALI survivors and non-survivors. To test our hypotheses we will analyze BAL samples from the NHLBI biorepository obtained from the ARDSnet LaSRS trial, which provides BALF collected at two different time points. As a control population, we will also obtain BALF from mechanically ventilated patients with an at- risk diagnosis for ALI. We will perform assays measuring HMGB1, MMP-3 and -13, and sRAGE both in BALF. Metabolomic profiling of ARDS patients will be performed via high-resolution mass spectrometry. The long- term goal is to develop an affordable approach that can be used for predicting disease susceptibility, diagnosis, risk stratification, response to therapy and prognosis.