PSEUDOMONAS PRODUCTS, OXYGEN RADICALS, AND LUNG INJURY

假单胞菌产物、氧自由基和肺损伤

• 批准号: 6124279
• 负责人: BRADLEY E BRITIGAN
• 金额: $ 22.49万
• 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 2003-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6124279
• 关键词: Pseudomonas aeruginosa; bacterial cytopathogenic effect; bacterial pigment; bacterial toxins; cell transplantation; cellular pathology; cystic fibrosis; cytotoxicity; free radical oxygen; interleukin 8; lung injury; microorganism culture; oxidative stress; protein purification; respiratory epithelium; tissue /cell culture

Pseudomonas aeruginosa causes acute nosocomial pneumonia as well as chronic lung infections in cystic fibrosis patients. The mechanisms responsible for the resulting lung injury remain unclear. Formation of oxidant species such as superoxide and hydrogen peroxide are associated with many forms of lung injury. During the initial funding period of this program, we obtained evidence that three compounds actively secreted by P. aeruginosa damage pulmonary epithelial and endothelial cells via oxidant production. In the next funding period we will define the cellular mechanisms of action of redox cycling. This results in superoxide and hydrogen peroxide generation. Pyocyanin causes a host of deleterious effects on cellular functions both in vitro and in vivo. In spite of this, there is only limited data on the cellular events by cells. Furthermore, the site(s), mechanism(s), and nature of the oxidants produced by pyocyanin, as well as the cellular targets are also poorly understood. We hypothesize that the complex series of effects mediated by pyocyanin occur through its ability to induce site specific oxidant production which leads to the disruption of cellular energy generation and activation of oxidant sensitive signaling pathways. To test this hypothesis three specific aims will be accomplished. Aim 1 is to identify the mechanism(s) of epithelial cell acquisition, cellular trafficking, and metabolism of pyocyanin under in vitro conditions. Aim 2 is to determine how pyocyanin deplete epithelial cells of ATP and cAMP by defining the effects of pyocyanin on oxidative phosphorylation and glycolysis. This aim will also address if pyocyanin acts on oxidant-regulated signaling pathways, IL-8 expression will serve as a model system. The first two aims will use an in vitro system of polarized epithelial cell monolayers using normal and CF cells. Aim 3 will examine the extent to which the in vitro effects of pyocyanin are observed occur under in vivo conditions. This work will focus on IL-8 release and utilize xenografts of human respiratory epithelial cells in SCID mice. These studies will use state of the art technique of cell biology and oxidant chemistry to define novel and previously unexplored mechanisms whereby P. aeruginosa may contribute to acute and/or chronic lung injury.

铜绿假单胞菌可引起急性院内肺炎 囊性纤维化患者的慢性肺部感染。机制 造成肺损伤的原因尚不清楚。的形成 氧化剂如超氧化物和过氧化氢相关 患有多种形式的肺损伤。在本次初始资助期间 计划中，我们获得了 P. 主动分泌的三种化合物的证据。 铜绿假单胞菌通过氧化剂损伤肺上皮和内皮细胞 生产。在下一个资助期内，我们将定义蜂窝 氧化还原循环的作用机制。这会产生超氧化物和 过氧化氢的产生。绿脓素会引起一系列有害物质 对体外和体内细胞功能的影响。尽管如此， 关于细胞的细胞事件的数据有限。此外， 产生氧化剂的位点、机制和性质 对绿脓素以及细胞靶标也知之甚少。我们 假设发生了由绿脓素介导的一系列复杂的效应 通过其诱导位点特异性氧化剂产生的能力，从而导致 破坏细胞能量产生和氧化剂激活 敏感的信号通路。为了检验这个假设的三个具体目标 将会实现。目标 1 是确定上皮细胞的机制 细胞获取、细胞运输和绿脓素代谢 体外条件。目标 2 是确定绿脓素如何消耗 通过定义绿脓素对 ATP 和 cAMP 上皮细胞的影响 氧化磷酸化和糖酵解。这一目标还将解决如果 绿脓素作用于氧化剂调节的信号通路、IL-8 表达 将作为一个模型系统。前两个目标将使用体外 使用正常细胞和 CF 细胞的极化上皮细胞单层系统。 目标 3 将检查绿脓素的体外影响程度 观察到在体内条件下发生。这项工作将重点关注 IL-8 释放并利用人呼吸道上皮细胞的异种移植物 SCID小鼠。这些研究将使用最先进的细胞技术 生物学和氧化化学来定义新颖的和以前未探索过的 铜绿假单胞菌可能导致急性和/或慢性的机制 肺损伤。