Neutrophil Priming in Trauma and Sepsis

描述（由申请方提供）：创伤和脓毒症后的神经元引发和激活是导致成人呼吸窘迫综合征（ARDS）、急性肺损伤（ALI）和多器官衰竭综合征（MOSF）的关键事件。在损伤和脓毒症后由细胞因子引发的呼吸爆发导致NADPH氧化酶产生过量的超氧化物，从而导致自身炎性组织损伤。然而，许多参与NADPH氧化酶引发和激活的分子机制仍然不清楚。我们的长期目标是发展一个详细的分子理解的蛋白激酶和脂质激酶信号通路，包括PI 3-激酶通路，p38 MAPK通路和Erk 1/2通路调节组装，亚细胞靶向，和活动的中性粒细胞NADPH氧化酶在启动和激活。我们以前的工作和初步观察确定PX结构域的p47 phox和p40 phox亚基作为模块化的蛋白质结构域，结合PI 3-激酶的特定脂质产物，并表明，引发剂PAF和TNF 1诱导组装的p47 phox：p67 phox：p40 phox异源三聚体复合物在引发，但未激活的细胞的细胞质中。在本提案中概述的研究中，我们使用生物化学、细胞生物学和小鼠模型研究了PX结构域介导的与脂质和细胞骨架的相互作用以及p47 phox与含PDZ结构域蛋白的结合在中性粒细胞引发和活化中的重要性。此外，我们进一步探讨蛋白激酶依赖的分子机制，在引发过程中异源三聚体的形成。这些研究的结果可能有助于开发新的诊断或治疗试剂，旨在限制患者因败血症和创伤而遭受的自身炎症组织损伤。公共卫生相关性3创伤和脓毒症后的神经元预充和激活是导致成人呼吸窘迫综合征（ARDS）、急性肺损伤（ALI）和多器官衰竭综合征（MOSF）的关键事件，这些是成人外科重症监护室的主要死亡原因。在损伤和脓毒症后由细胞因子引发的中性粒细胞呼吸爆发导致NADPH氧化酶产生过量的超氧化物，并导致在这些综合征中观察到的自身炎性组织损伤。我们的研究旨在更好地了解创伤和脓毒症后NADPH氧化酶的调节，并促进新型诊断和治疗药物的开发，以减少这些危重患者的组织损伤，发病率和死亡率。

DESCRIPTION (provided by applicant): Neutrophil priming and activation following trauma and sepsis is a key event implicated in causing Adult Respiratory Distress Syndrome (ARDS), Acute Lung Injury (ALI) and Multi-Organ Failure Syndrome (MOSF). Priming of the respiratory burst by cytokines following injury and sepsis results in excessive superoxide production by the NADPH oxidase leading to auto-inflammatory tissue damage. Many of the molecular mechanisms involved in priming and activation of the NADPH oxidase, however, remain poorly defined. Our long-term goal is to develop a detailed molecular understanding of how protein kinase and lipid kinase signaling pathways, including the PI 3-kinase pathway, the p38MAPK pathway and the Erk1/2 pathways regulate the assembly, subcellular targeting, and activity of the neutrophil NADPH oxidase during priming and activation. Our previous work and preliminary observations identified PX domains in the p47phox and p40phox subunits as modular protein domains that bind to specific lipid products of PI 3-kinase, and showed that the priming agents PAF and TNF1 induced the assembly of a p47phox:p67phox:p40phox heterotrimeric complex in the cytoplasm of primed but un-activated cells. In the studies outlined in this proposal we investigate the importance of PX domain-mediated interactions with lipids and the cytoskeleton, and p47phox binding to PDZ- domain-containing proteins, in neutrophil priming and activation using biochemistry, cell biology and mouse models. In addition, we further explore protein kinase-dependent molecular mechanisms involved in heterotrimer formation during priming. The results from these studies may assist in the development of novel diagnostic or therapeutic reagents aimed at limiting the auto-inflammatory tissue damage patients suffer as a result of sepsis and trauma. PUBLIC HEALTH RELEVANCE3 Neutrophil priming and activation following trauma and sepsis is a key event implicated in causing Adult Respiratory Distress Syndrome (ARDS), Acute Lung Injury (ALI) and Multi-Organ Failure Syndrome (MOSF), which are the leading causes of death in adult surgical intensive care units. Priming of the neutrophil respiratory burst by cytokines following injury and sepsis results in excessive superoxide production by the NADPH oxidase and contributes to the auto-inflammatory tissue damage seen in these syndromes. Our research is designed to better understand regulation of the NADPH oxidase following trauma and sepsis, and facilitate the development of novel diagnostic and therapeutic agents that will reduce tissue damage, morbidity and mortality in these critically ill patients.