A novel anti-inflammatory role for the neutrophil NADPH oxidase

中性粒细胞 NADPH 氧化酶的新型抗炎作用

• 批准号: 8900925
• 负责人: JESSICA G MORELAND
• 金额: $ 19.88万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8900925
• 关键词: Allergic Reaction; Anti-Inflammatory Agents; Anti-inflammatory; Antioxidants; Catalytic Domain; Cells; Cellular biology; Clinical; Complex; Confocal Microscopy; Data; Disease; Down-Regulation; Elements; Endosomes; Endotoxins; Enzymes; Equilibrium; Event; Failure; Family; Generations; Goals; Health; Homeostasis; Host Defense; Human; Immune; Immune response; Immune system; In Vitro; Infection; Inflammation; Inflammatory; Inflammatory Response; Intensive Care; Intensive Care Units; Interphase Cell; Investigation; Knowledge; Laboratories; Lead; Leukocytes; Life; Mediating; Medicine; Minor; Mitogen-Activated Protein Kinases; Modeling; Molecular Target; Mus; NADPH Oxidase; Outcome; Oxidants; Oxidases; Oxygen; Pathogenesis; Pathway interactions; Patients; Phase; Phenotype; Process; Protein phosphatase; Publishing; Reactive Oxygen Species; Regulation; Research; Resolution; Rest; Risk; Role; Sepsis; Sepsis Syndrome; Shock; Signal Pathway; Signal Transduction; Sterility; Stimulus; Superoxides; Syndrome; Testing; Tissues; Trauma; Vesicle; base; cell type; cellular targeting; clinical practice; human MAPK14 protein; immune activation; improved; killings; member; microbial; monocyte; mortality; neutrophil; novel; novel therapeutics; response; segregation; upstream kinase

DESCRIPTION (provided by applicant): Local and systemic inflammatory events elicit immune activation in the host to provide the necessary pro- inflammatory response based on the danger sensed, followed by active resolution and return to baseline. One common clinical example of this process is the Systemic Inflammatory Response Syndrome (SIRS), which can be activated following a range of insults that may include infection, shock, allergic reaction, or trauma. This pro- inflammatory phase of the immune response is overlapped by a compensatory anti-inflammatory response that restores immune homeostasis. Circulating neutrophils (PMN) are critically involved in mediating the consequences of systemic inflammation, in part by the generation of reactive oxygen species (ROS). PMN produce ROS via activation of the NADPH oxidase (Nox), with Nox2 (gp91phox) being the catalytic subunit in this cell type. Despite the unequivocal requirement for neutrophil-derived ROS in microbial defense, it is clearly recognized that PMN activation can lead to host tissue damage. This well-studied proinflammatory activation of PMN is counterbalanced against recent evidence supporting an anti-inflammatory role for Nox2. The current proposal focuses on defining cellular effects and molecular targets of ROS signaling in resting PMNs, and investigation of an anti-inflammatory role of Nox2 in termination of inflammation. These goals are predicated on two subsets of strong preliminary data: 1) demonstration of specific pro-inflammatory phenotypic alterations in resting PMNs in the absence of NADPH oxidase function, and 2) enhanced and persistent inflammation and increased mortality in Nox2-deficient mice using a murine model of sterile generalized inflammation. The overall hypothesis of this proposal is that Nox2 in PMN has an essential anti-inflammatory role in the regulation of the host inflammatory state. Furthermore, we hypothesize that Nox2-derived ROS are required both to maintain resting cellular quiescence and to return to homeostasis following an inflammatory insult. These hypotheses will be tested with the following aims: 1) Nox2 is active in unstimulated PMN and necessary to maintain the resting cell phenotype. 2) Nox2 has anti-inflammatory effects in PMN mediated via the p38 mitogen-activated protein kinase (MAPK) pathway. The approach to these aims will include sophisticated analysis of subcellular vesicles/endosomes of unstimulated human PMN for evidence of assembly and activation of Nox2. In addition, focused exploration of cellular targets of anti-inflammatory ROS signaling, and downstream consequences of this signaling will be undertaken. Primary human PMNs will be used for in vitro analyses of signaling pathways and confocal microscopy will be employed to localize ROS signals. A better understanding of the cell biology of host inflammation will be relevant to numerous disease processes.

描述（由申请人提供）：局部和全身性炎症事件引起宿主的免疫激活，根据感知到的危险提供必要的促炎反应，随后主动解决并恢复到基线。这一过程的一个常见临床例子是全身性炎症反应综合征（SIRS），它可以在一系列损伤（包括感染、休克、过敏反应或创伤）后激活。这种免疫反应的前炎症阶段与恢复免疫稳态的代偿性抗炎反应重叠。循环中性粒细胞（PMN）在介导全身性炎症的后果中起着至关重要的作用，部分原因是活性氧（ROS）的产生。PMN通过激活NADPH氧化酶（Nox）产生ROS，其中Nox2 （gp91phox）是该细胞类型的催化亚基。尽管在微生物防御中明确要求中性粒细胞来源的ROS，但人们清楚地认识到，PMN激活可导致宿主组织损伤。这种经过充分研究的PMN的促炎激活与最近支持Nox2抗炎作用的证据相平衡。目前的建议侧重于确定静息PMNs中ROS信号的细胞效应和分子靶点，并研究Nox2在炎症终止中的抗炎作用。这些目标基于两组强有力的初步数据：1)在缺乏NADPH氧化酶功能的情况下，静息PMNs的特异性促炎表型改变；2)在无菌全能性炎症小鼠模型中，nox2缺陷小鼠的炎症增强和持续，死亡率增加。本研究的总体假设是PMN中的Nox2在调节宿主炎症状态中具有重要的抗炎作用。此外，我们假设nox2衍生的ROS既需要维持静息细胞静止，也需要在炎症损伤后恢复稳态。这些假设将通过以下目的进行验证：1)Nox2在未受刺激的PMN中是活跃的，并且是维持静息细胞表型所必需的。2) Nox2在p38丝裂原活化蛋白激酶（MAPK）途径介导的PMN中具有抗炎作用。实现这些目标的方法将包括对未受刺激的人PMN的亚细胞囊泡/内体进行复杂的分析，以寻找Nox2组装和激活的证据。此外，将重点探索抗炎ROS信号的细胞靶点，以及该信号的下游后果。原代人pmn将用于体外信号通路分析，共聚焦显微镜将用于定位ROS信号。更好地了解宿主炎症的细胞生物学将与许多疾病过程相关。