PSEUDOMONAS PRODUCTS, OXYGEN RADICALS, AND LUNG INJURY

假单胞菌产物、氧自由基和肺损伤

• 批准号: 2070249
• 负责人: BRADLEY E BRITIGAN
• 金额: $ 17.11万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-12-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2070249
• 关键词: Pseudomonas aeruginosa; bacterial pigment; cell adhesion; copper; cytotoxicity; elastases; free radical oxygen; hydrogen peroxide; hydroxyl radical; interleukin 1; iron; lung injury; metal complex; microorganism culture; neutrophil; platelet activating factor; prostacyclins; protein purification; respiratory epithelium; siderophores; superoxides; tissue /cell culture; transferrin; tumor necrosis factor alpha; vascular endothelium

Pseudomonas aeruginosa causes acute and chronic infections of the lung and other sites resulting in marked tissue damage. Formation of reactive oxygen species such as superoxide (O2) hydrogen peroxide (H2O2), and hydroxyl radical (OH) has been increasingly implicated in tissue injury associated with a wide array of human pathology. OH, generated via the iron (Fe)-catalyzed reaction of O2 and H2O2, is the most reactive of the oxygen free radical. Recent work from our laboratory has suggested that three compounds actively secreted by P. aeruginosa may alone, or in conjunction with neutrophil (PMN)-derived O2/H2O2, lead to OH generation and subsequent tissue injury. These P. aeruginosa-derived products are: pyochelin, a P. aeruginosa siderophore (Fe-chelator) which P. aeruginosa employs to acquire microenvironmental FE and which we found is an effective OH catalyst; pseudomonas elastase, aP. aeruginosa protease which we found cleaves the human Fe-binding protein transferrin to form new Fe chelates capable of catalyzing OH production; and pyocyanin aP aeruginosa product which can undergo cell-mediated aerobic redox cycling which results in the generation of O2 and H2O2. The goal of the work proposed is to investigate the potential specific aims have been targeted for study. Aim 1 will assess whether the iron-pyochelin complex, ferripyochelin (Fe-derived O2 and H2O2 by inducing the generation of OH near the cell membrane. Aim 2 will determine what oxidant species are generated during the interaction of Fe-pyochelin with O2/H2O2 what features of the pyochelin molecule serve to promote its ability to enhance O2/H2O2-cell injury, and whether a copper-pyochelin enhances pyocyanin-mediated cytotoxicity by catalyzing OH generation. Aim 4 will determine if pseudomonas elastase cleavage of transferrin also enhances O2/H2O mediated injury of pulmonary epithelial and endothelial cells through OH catalysis. Aim 5 will investigate whether the generation of oxidants by these P aeruginosa products alters endothelial cell function a as to further promote tissue injury by: increasing neutrophil adherence to endothelial cells by modulating the expression of adherence ligands or platelet activating factor (PAF) on the endothelial cell surface: decreasing endothelial cell prostacyclin production: or increasing endothelial cell release of pro-inflammatory cytokines such as TNF an dIL-1. Thus, these studies will explore novel and previously unexplored mechanisms whereby P. aeruginosa-derived products could contribute to lung injury by inducing the production of toxic oxygen species. Such information could eventually result in the design of new therapeutic intervention to decrease the morbidity and mortality of infections of the lung and other organs with P. aeruginosa and related bacterial pathogens.

铜绿假单胞菌引起急性和慢性肺部感染 和其他部位导致明显的组织损伤。 反应性的形成 氧物质，例如超氧化物 (O2)、过氧化氢 (H2O2)，以及 羟自由基 (OH) 与组织损伤的关系日益密切 与多种人类病理学相关。 哦，通过生成 铁 (Fe) 催化的 O2 和 H2O2 反应是反应性最强的 氧自由基。 我们实验室最近的工作表明 铜绿假单胞菌主动分泌的三种化合物可以单独或在 与中性粒细胞 (PMN) 衍生的 O2/H2O2 结合，导致 OH 生成 以及随后的组织损伤。 这些铜绿假单胞菌衍生产品是： 脓螯素，一种铜绿假单胞菌铁载体（铁螯合剂），其中铜绿假单胞菌 用来获取微环境有限元，我们发现这是一个 有效的OH催化剂；假单胞菌弹性蛋白酶，aP。铜绿假单胞菌蛋白酶 我们发现它会裂解人类铁结合蛋白转铁蛋白以形成 能够催化 OH 产生的新型铁螯合物；和绿脓素aP 可以进行细胞介导的有氧氧化还原循环的铜绿假单胞菌产品 从而产生 O2 和 H2O2。 工作目标 提议是调查潜在的具体目标已针对 用于学习。 目标 1 将评估铁-绿脓素复合物是否 ferripyochelin（Fe 衍生的 O2 和 H2O2，通过诱导 OH 的生成 靠近细胞膜。 目标 2 将确定氧化剂种类是什么 Fe-pyochelin 与 O2/H2O2 相互作用时生成什么 绿脓菌素分子的特征有助于促进其能力 增强 O2/H2O2 细胞损伤，以及铜绿脓素是否增强 绿脓素通过催化 OH 的产生介导细胞毒性。 目标4将 确定假单胞菌弹性蛋白酶对转铁蛋白的裂解是否也增强 O2/H2O介导的肺上皮细胞和内皮细胞损伤 通过OH催化。 目标 5 将调查是否产生 这些铜绿假单胞菌产物产生的氧化剂改变内皮细胞功能 a 通过以下方式进一步促进组织损伤： 增加中性粒细胞粘附 通过调节粘附配体的表达作用于内皮细胞 或内皮细胞表面的血小板激活因子（PAF）： 减少内皮细胞前列环素的产生：或增加 内皮细胞释放促炎细胞因子，例如 TNF 和 dIL-1。 因此，这些研究将探索新颖的和以前未探索过的 铜绿假单胞菌衍生产品可能有助于的机制 诱导有毒氧的产生而损伤肺。 这样的 信息最终可能导致新疗法的设计 降低感染发病率和死亡率的干预措施 肺和其他器官有铜绿假单胞菌和相关细菌病原体。