Eicosanoid Production By Infected Lung Epithelial Cells

描述(由申请人提供)：在过去的9年里，在我的研究生和研究生学习期间，粘膜表面的炎症机制一直是一个主要的焦点。中性粒细胞(PMN)在呼吸道粘膜的募集是肺炎、囊性纤维化和慢性阻塞性肺疾病等疾病的病理特征。我正在使用体外模型研究一种新的炎症途径，该模型由生长在Transwell过滤器上的肺上皮细胞和分离的人PMN组成。在这个模型中，肺上皮细胞的细菌感染导致上皮细胞分泌一种PMN化学吸引剂，引导PMN穿过上皮。在我的博士后培训期间，我们确定这种PMN化学引诱剂是二十烷类化合物，海波西林A3(HXA3)。这项建议描绘了一种有重点的方法来确定感染的肺上皮中负责HXA3合成的酶。具体来说，将分析磷脂酶A2(PLA2)和12-脂氧合酶(12-LOS)。PLA2酶主要负责生成花生四烯酸，花生四烯酸是所有二十烷类化合物的前体，12-LO介导花生四烯酸转化为HXA3。肺上皮细胞和病原菌都具有PLA2活性，在这项提议中，我们将研究PLA2的每个来源对HXA3产生的贡献。未来的研究将使用更复杂和/或更多与疾病相关的模型来评估HXA3的作用，如气液界面培养、CFTR突变的上皮细胞、与上皮-内皮细胞单层共培养、整个组织和整个动物。此外，未来一个重要的考虑包括分析患有黏膜炎症情况的患者的组织，以确定是否观察到对HXA3产生至关重要的酶的表达增加。彻底了解这一未知途径将导致选择性阻断HXA3产生的策略。我的长期职业目标是开发治疗方法，减轻粘膜表面的破坏性炎症。可能从这一治疗策略中受益的疾病并不是肺独有的。皮肤、泌尿生殖道和肠道的感染，以及银屑病和炎症性肠病等特发性疾病，都在上皮表面共享破坏性的PMN渗透，并可能涉及HXA3合成的调节障碍。这些研究最终可能导致一系列全新的抗炎药物的开发，这些药物对多种病理疾病有效。

DESCRIPTION (provided by applicant): Inflammatory mechanisms at mucosal surfaces have been a major focus over the past 9 years during my graduate and post-graduate studies. Recruitment of neutrophils (PMNs) to the airway mucosa is a pathological hallmark of diseases such as pneumonia, cystic fibrosis and chronic obstructive pulmonary disease. I am investigating a novel inflammatory pathway using an in vitro model consisting of lung epithelial cells grown on Transwell filters and isolated human PMNs. In this model, bacterial infection of lung epithelia cause epithelial secretion of a PMN chemo-attractant, which directs PMNs to cross the epithelium. During my post-doctoral training, we identified this PMN chemo-attractant as the eicosanoid, hepoxilin A3 (HXA3). This proposal delineates a focused approach to identify enzymes responsible for HXA3 synthesis in the infected lung epithelium. Specifically, phospholipase A2s (PLA2) and 12-lipoxygenases (12-LOs) will be analyzed. PLA2 enzymes are primarily responsible for generation arachidonic acid, which is the precursor of all eicosanoids and 12-LO mediates the conversion of arachidonic acid into HXA3. Both lung epithelial cells and pathogenic bacteria possess PLA2 activity and we will investigate the contribution of each source of PLA2 towards the production of HXA3 in this proposal. Future studies will evaluate to role of HXA3 using more complex and/or more disease relevant models such as air-liquid interface cultures, CFTR mutant epithelial cells, co-cultures with epithelial-endothelial monolayers, whole tissue, and whole animal. Also, an important future consideration involves the analysis of tissues from patients with mucosal inflammatory conditions to determine if an increased expression of enzymes critical for HXA3 production is observed. A thorough understanding of this unexplored pathway will lead to strategies that selectively block HXA3 production. My long-term career goal is to develop therapeutics that alleviates destructive inflammation at mucosal surfaces. Diseases that may benefit from this therapeutic strategy are not exclusive to the lung. Infections of the skin, urogenital tract, and gut, as well as idiopathic conditions such as psoriasis and inflammatory bowel disease all share destructive PMN infiltration at the epithelial surface and may involve dys-regulation of HXA3 production. These studies could ultimately result in the development of an entirely new series of anti-inflammatory drugs having efficacy towards a wide range of pathologies