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， 暴露，如职业暴露于室内污染，占20-25%的COPD病例， 美国的暴露于猪隔离设施（SCF）内的有机粉尘是一个重要的可改变的因素， SCF工人肺部疾病的危险因素。许多报告承认， 超临界流体有机粉尘暴露与广谱慢性炎症性肺疾病的发生 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 与农业有关的可持续发展的管理机制仍不清楚。领域的挑战 农业相关的肺病研究包括重建SCF暴露条件的困难和 缺乏研究“真实的世界”接触的生理学相关动物模型。初步数据显示， SCF猪是早期气道上皮损伤和反应的模型，如表型病变所证明的 CB的特征包括分泌的气道粘蛋白水平增加，气道含有杯状细胞 与非SCF（牧场）猪相比，SCF可导致增生、炎症和平滑肌肥大的迹象。 在本研究中，我们将探讨SCF有机粉尘对气道上皮细胞的损伤机制和反应 通过比较SCF和非SCF猪的肺组织的行为。确定炎症来源 介质，肺白细胞，肺切片和猪气管支气管上皮细胞（PTBE）的反应， 将比较SCF和非SCF对内毒素的影响（目的1）。钙/钙调蛋白依赖性蛋白激酶II （CaMKII），一种受氧化应激调节并与肺纤维化有关的激酶，在肺纤维化中更丰富。 SCF猪的气道上皮组织与非SCF猪相比。因此，使用各种抑制剂的研究将 以确定CaMK II和氧化应激在气道炎症激活中的作用 途径，包括核因子κ B，使用来自SCF猪的PTBE细胞（Aim 2）。鉴于遵守 SCF猪气道上皮杯状细胞增生，我们将利用全面的蛋白质组学 在猪模型中鉴定与杯状细胞增生相关的分子途径的方法（目的3）。 利用全局和靶向蛋白质组学方法， 将鉴定细胞增生和粘液分泌。关于调节杯状蛋白的分子途径的知识 细胞增生将作为开发新的治疗策略来治疗CB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.