Lung epithelial cell survival signaling in ozone in cystic fibrosis and normals

囊性纤维化和正常人臭氧中肺上皮细胞存活信号传导

• 批准号: 7269499
• 负责人: Carl W White
• 金额: $ 31.62万
• 依托单位: NATIONAL JEWISH HEALTH
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-23 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7269499
• 关键词: 1-Phosphatidylinositol 3-Kinase; Acute; Agonist; Air; Air Pollutants; Alveolar; Apical; Apoptosis; Appearance; Asthma; Bacterial Infections; Bronchoalveolar Lavage; Calcium; Cell Death; Cell Polarity; Cell Survival; Cells; Cessation of life; Chronic Obstructive Airway Disease; Clinical; Clinical Research; Cultured Cells; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Defense Mechanisms; Dependence; Development; Developmental Therapeutics Program; Disease; Early treatment; Energy Metabolism; Epithelial; Epithelial Cells; Epithelium; Event; Excision; Exocytosis; Free Radicals; Gases; Human; In Vitro; Inflammatory; Injury; Interleukin-8; Kinetics; Liquid substance; Lung; Measures; Mediating; Metabolic; Metabolic Pathway; Mouse Strains; Mus; Mutant Strains Mice; Necrosis; Oxidants; Oxygen; Ozone; Particulate; Pathologic; Process; Purines; Range; Regulation; Resistance; Rho-associated kinase; Risk; Role; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Supplementation; Surface; Ultrafine; Uridine Triphosphate; Ursidae Family; airway epithelium; airway inflammation; analog; bronchial epithelium; cell injury; cystic fibrosis airway; cystic fibrosis airway epithelia; cytokine; extracellular; in vivo; injury and repair; monolayer; mutant; ozone exposure; prevent; purine; receptor; repaired; respiratory; response

DESCRIPTION (provided by applicant): Oxidant air pollutants like ozone increase risk for exacerbation of cystic fibrosis, asthma, and COPD. Ultrafine particulates, which also can bear surface free radicals, can have such effects, alone or in synergy with ozone. Oxidant gases like supraphysiologic oxygen and ozone cause extracellular ATP release from lung cells, activating critical survival signals. Prompt, reversible ATP release due to ozone (50-200 ppb) occurs in tracheal, bronchial, small airway, and alveolar epithelial cells, appears due to calcium-, rho kinase-, and PI 3-kinase-dependent vesicular exocytosis, and, in polarized bronchial epithelium, is mainly from the apical surface. Acute ozone exposure also causes ATP release into lung epithelial lining fluid in mice within 15 min. In vitro, enzymatic removal of extracellular ATP increases cell death, while ATP, DTP, or a nonhydrolyzable ATP analog prevent ozone-induced apoptosis and necrosis. The protecting agonists, and their inhibition by P2 and P2Y receptor-specific antagonists, indicate a role for P2Y receptors. Extracellular ATP activates ERK 1/2 and Akt signaling. Besides epithelial injury, ozone causes release of cytokines like interleukin-8 (IL-8). IL-8 appears in CF airways even before bacterial infection, being the earliest identified pathologic event. We hypothesize that extracellular ATP preserves epithelial energy metabolism, airway cell survival and inhibits IL-8 release due to ozone in normals, that impaired ATP release in CF airways causes opposite effects, and that supplemental extracellular ATP or similar agonists will reverse these processes in CF and normals. Our specific aims are: (1) measure ATP release, IL-8 release, and cell death in CF and non-CF airway human epithelium in response to ozone, (2) quantitate ozone-mediated ATP release, inflammatory cytokine release, and cell injury/death in airways of CFTR- mutant and non-mutant mice, (3) assess effects of ATP, DTP and ATP analog supplementation in CF and non-CF airway epithelium in ozone in vitro and in vivo, and determine activated signaling pathways and related metabolic effects. Polarized monolayers of primary and transformed CF-mutant and normal airway epithelium cultured on permeable supports with an air-liquid interface will be used. These studies will increase our understanding of lung oxidant injury and repair in CF and normals, and of normal defense mechanisms of airway epithelium.

描述（由申请人提供）：臭氧等氧化剂空气污染物会增加囊性纤维化、哮喘和慢性阻塞性肺病恶化的风险。超细颗粒也可以携带表面自由基，可以单独或与臭氧协同产生这样的效果。超生理氧气和臭氧等氧化剂气体会导致肺细胞释放细胞外 ATP，激活关键的生存信号。由于臭氧 (50-200 ppb) 导致气管、支气管、小气道和肺泡上皮细胞中发生迅速、可逆的 ATP 释放，这是由于钙、rho 激酶和 PI 3 激酶依赖性囊泡胞吐作用而出现，并且，在极化的支气管上皮中，主要来自心尖面。急性臭氧暴露还会导致小鼠在 15 分钟内将 ATP 释放到肺上皮内层液中。在体外，酶促去除细胞外 ATP 会增加细胞死亡，而 ATP、DTP 或不可水解的 ATP 类似物可防止臭氧诱导的细胞凋亡和坏死。保护性激动剂以及 P2 和 P2Y 受体特异性拮抗剂对其的抑制表明 P2Y 受体的作用。细胞外 ATP 激活 ERK 1/2 和 Akt 信号传导。除了上皮损伤之外，臭氧还会导致白细胞介素 8 (IL-8) 等细胞因子的释放。 IL-8 甚至在细菌感染之前就出现在 CF 气道中，是最早发现的病理事件。我们假设正常情况下细胞外 ATP 可以保护上皮能量代谢、气道细胞存活并抑制臭氧引起的 IL-8 释放，CF 气道中 ATP 释放受损会产生相反的效果，而补充细胞外 ATP 或类似激动剂将逆转 CF 中的这些过程和法线。我们的具体目标是：(1) 测量 CF 和非 CF 气道上皮对臭氧的反应中 ATP 释放、IL-8 释放和细胞死亡，(2) 定量臭氧介导的 ATP 释放、炎症细胞因子释放和细胞死亡。 CFTR突变型和非突变型小鼠气道损伤/死亡，（3）在体外和体内臭氧中评估CF和非CF气道上皮中ATP、DTP和ATP类似物补充剂的影响，以及确定激活的信号通路和相关的代谢效应。将使用在具有气液界面的可渗透支持物上培养的原代和转化的 CF 突变体和正常气道上皮的偏振单层。这些研究将增加我们对 CF 和正常人的肺氧化损伤和修复，以及气道上皮正常防御机制的了解。