PSEUDOMONAS PRODUCTS, OXYGEN RADICALS, AND LUNG INJURY

铜绿假单胞菌引起急性医院获得性肺炎以及 囊性纤维化患者的慢性肺部感染。的机制 导致肺损伤的原因尚不清楚。形成 氧化剂物质如超氧化物和过氧化氢 多种形式的肺损伤。在最初的融资期间， 程序，我们获得的证据表明，三个化合物积极分泌的P。 铜绿假单胞菌通过氧化损伤肺上皮和内皮细胞 生产在下一个融资期，我们将定义蜂窝 氧化还原循环的作用机制。这导致超氧化物和 产生过氧化氢。绿脓菌素会导致大量有害的 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只有有限的数据。此外，委员会认为， 产生氧化剂的部位、机制和性质 绿脓菌素以及细胞靶点也知之甚少。我们 假设绿脓菌素介导的一系列复杂效应发生 通过其诱导位点特异性氧化剂产生的能力， 破坏细胞能量产生和氧化剂活化 敏感的信号通路。为了验证这一假设， 将被完成。目的1是确定上皮细胞的机制， 细胞获取、细胞运输和绿脓菌素的代谢 在体外条件下。目的2是确定绿脓菌素如何消耗 上皮细胞的ATP和cAMP，通过定义绿脓菌素对 氧化磷酸化和糖酵解。这一目标还将解决，如果 绿脓菌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 使用正常和CF细胞的极化上皮细胞单层系统。 目的3将研究绿脓菌素在体外的影响程度 在体内条件下观察到。这项工作将集中在IL-8 释放和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， 生物学和氧化剂化学来定义新的和以前未探索的 铜绿假单胞菌可能导致急性和/或慢性 肺损伤

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.