Mechanisms of Airway Epithelial Injury and Response

摘要 吸烟是慢性阻塞性肺疾病(COPD)的主要原因；然而，其他 暴露，如职业暴露于室内污染，占慢性阻塞性肺疾病病例的20%-25% 美国。暴露在猪隔离设施(SCF)内的有机粉尘是一个重要的可修改的 超临界流体作业工人肺部疾病的危险因素许多报告都认识到重复的 SCF有机粉尘暴露与多种慢性炎症性肺部疾病的发展 包括慢性支气管炎(CB)--COPD的两种主要形式之一。然而，细胞和分子 与农业有关的可再生能源的发展机制仍不清楚。在以下领域的挑战 与农业相关的肺部疾病研究包括重建SCF暴露条件的困难以及 缺乏生理上相关的动物模型来研究“真实世界”的暴露。我们的初步数据显示， SCF猪是早期呼吸道上皮损伤和反应的模型，表型病变证明了这一点 慢性支气管炎的特点包括分泌的呼吸道粘蛋白水平增加，呼吸道含有杯状细胞 与非SCF(牧场)猪相比，有增生、炎症和平滑肌肥大的迹象。 在这项计划中，我们将研究呼吸道上皮损伤的机制和对SCF有机粉尘的反应 通过比较SCF猪和非SCF猪肺组织的行为。找出炎症的来源 肺白细胞、肺切片和猪气管-支气管壁上皮(PTBE)细胞的介质反应 比较SCF和非SCF对内毒素的影响(目标1)。钙/钙调蛋白依赖的蛋白激酶II (CaMKII)是一种受氧化应激调节并参与肺纤维化的激酶，在 SCF猪与非SCF猪的呼吸道上皮组织比较。因此，使用各种抑制剂的研究将 确定CaMKII和氧化应激在激活呼吸道炎症中的作用 使用来自SCF猪的PTBE细胞的途径，包括核因子kappa B(目标2)。由于遵守了 SCF猪呼吸道上皮中的杯状细胞增生，我们将利用综合蛋白质组学 在猪模型中识别与杯状细胞增生相关的分子途径的方法(目标3)。 利用全球和靶向蛋白质组学方法，控制高脚杯的启动和进展的途径 细胞增生和粘液分泌将被识别。关于调控高脚杯的分子途径的知识 细胞增殖将成为治疗慢性支气管炎的新治疗策略的潜在靶点 影响到农业工人和普通民众。

ABSTRACT Cigarette smoking is the leading cause of chronic obstructive pulmonary disease (COPD); however, other exposures, such as occupational exposure to indoor pollution accounts for 20-25% of COPD cases in the United States. Exposure to organic dusts within swine confinement facilities (SCF) is a significant modifiable risk factor for lung disease in SCF workers. Numerous reports recognize the association between repetitive SCF organic dust exposure and development of a broad spectrum of chronic inflammatory lung diseases including chronic bronchitis (CB) – one of two major forms of COPD. However, the cellular and molecular mechanisms governing development of agriculture-related CB remain unclear. Challenges in the field of agriculture-related lung disease research include the difficulty in recreating SCF exposure conditions and the lack of physiologically relevant animal models to study `real world' exposures. Our preliminary data show that SCF pigs are a model for early airway epithelium injury and response, as evidenced by phenotypic lesions characteristic of CB including increased levels of the secreted airway mucins, airways contain goblet cell hyperplasia, inflammation, and evidence of smooth muscle hypertrophy compared to non-SCF (pasture) pigs. In this proposal, we will investigate mechanisms of airway epithelial injury and response to SCF organic dust by comparing the behavior of lung tissue from SCF and non-SCF pigs. To identify sources of inflammatory mediators, responses of lung leukocytes, lung slices and porcine tracheobronchial epithelial (PTBE) cells from SCF and non-SCF to endotoxin will be compared (Aim 1). The calcium/calmodulin-dependent protein kinase II (CaMKII), a kinase regulated by oxidative stress and implicated in pulmonary fibrosis, is more abundant in airway epithelial tissue of SCF pigs compared to non-SCF pigs. Therefore, studies using various inhibitors will be conducted to determine the role of CaMKII and oxidative stress in activation of airway inflammation pathways, including nuclear factor kappa B, using PTBE cells from SCF pigs (Aim 2). Given the observance of goblet cell hyperplasia in the airway epithelia of SCF pigs, we will utilize comprehensive proteomics approaches to identify molecular pathways associated with goblet cell hyperplasia in porcine models (Aim 3). Utilizing global and targeted proteomics approaches, pathways governing initiation and progression of goblet cell hyperplasia and mucus secretion will be identified. Knowledge of molecular pathways that regulate goblet cell hyperplasia will serve as potential targets for development of novel therapeutic strategies to treat CB affecting agricultural workers and the general population.