Dual Oxidase in Airway Epithelial Repair and Remodeling

双氧化酶在气道上皮修复和重塑中的作用

• 批准号: 7533224
• 负责人: ALBERT VAN DER VLIET
• 金额: $ 36.87万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-05 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7533224
• 关键词: Actins; Address; Apical; Asthma; Biological; Biology; Breathing; Cell Adhesion; Cell Proliferation; Cell physiology; Cell surface; Cells; Chronic; Chronic Disease; Development; Disease; Endopeptidases; Environment; Environmental Risk Factor; Enzymes; Epidermal Growth Factor Receptor; Epithelial; Epithelial Cells; Epithelium; Event; Gelatinase B; Gland; Goals; Growth Factor; Homologous Gene; Host Defense; Human; Hydrogen Peroxide; In Vitro; Inflammatory; Injury; Interleukin-13; Interleukin-4; Invasive; Localized; Lung; Maintenance; Matrix Metalloproteinases; Mechanics; Mediating; Mediator of activation protein; Metalloproteases; Mitogen Receptors; Mitogen-Activated Protein Kinases; Modeling; Molecular; Mus; NADPH Oxidase; Naphthalene; Naphthalenes; Organ; Organism; Oxidants; Oxidases; Oxidation-Reduction; Oxidative Stress; Pathway interactions; Peptide Hydrolases; Phagocytes; Process; Production; Protein Isoforms; Protein Tyrosine Phosphatase; Proteins; Proteomics; Public Health; Purinergic P2 Receptors; Purinoceptor; Receptor Activation; Regulation; Role; Salivary; Signal Pathway; Signal Transduction; Small Interfering RNA; Stimulus; Sulfhydryl Compounds; Surface; Thinking; Tissues; Toxin; Tracheobronchial; Up-Regulation; Wound Healing; airway epithelium; airway remodeling; allergic airway disease; allergic airway inflammation; base; cell growth; cell motility; cytokine; extracellular; in vivo; in vivo Model; injured; injury and repair; insight; microbial; microorganism; migration; mouse model; receptor; repaired; response; response to injury; small hairpin RNA; wound

DESCRIPTION (provided by applicant): Recent studies have indicated the presence of new NADPH oxidase (Nox) homologs within the airways, with homology to phagocytic gp91phox (Nox2), that are responsible for apical epithelial production of H2O2 in response to various inflammatory or environmental stimuli. These Nox homologs, termed Dual Oxidases (Duox), exist as two isoforms, of which Duox1 is primarily expressed in the tracheobronchial epithelium, whereas Duox2 has been detected in salivary or submucosal glands. In addition to postulated roles in airway host defense, recent studies have suggested alternative functions of airway epithelial Duox1, including regulation of epithelial H+ transport and involvement in epithelial responses to injury by promoting production of growth factors, metalloproteinases, and cytokines, and stimulating epithelial cell migration and repair. Our recent studies have indicated Duox-mediated H2O2 production in tracheobronchial epithelial cells in response to mechanical injury, which is mediated by cellular release of ATP and stimulation of purinergic P2 receptors at the epithelial surface. Moreover, epithelial cell migration and wound repair were found to be mediated by ATP- mediated activation of mitogen-activated protein kinase (MAPK) pathways and activation of metalloproteinases including matrix metalloproteinase (MMP)-9, by mechanisms involving Duox1. Therefore, we hypothesize that Duox1 contributes to maintenance of airway epithelial barrier integrity, by stimulating epithelial repair processes in response to injury, by localized oxidative events at the epithelial surface and/or by activation of redox-dependent cellular signaling pathways. In addition, based on recent observations that Th2 cytokines (IL-13, IL-4) can induce epithelial Duox1 expression, and that lung Duox1 expression is markedly increased in a mouse model of allergic airway inflammation, we propose that exaggerated or persistent Duox1 activation may contribute to a chronic wound response and airway remodeling, as is observed in chronic asthma. The main objectives of this proposal are to identify the mechanisms by which Duox1 activation mediates epithelial cell migration and repair in vitro, and to establish the contribution of Duox1 to airway epithelial repair and remodeling in vivo. We will determine the contribution of extracellular or cellular H2O2 production and/or localized pH changes and H+ transport to Duox1-mediated epithelial cell migration (Aim 1), identify mechanisms involved in Duox1-dependent MAPK activation and growth factor/MMP activation (Aim 2), and characterize extracellular and cellular redox-sensitive targets of Duox1-derived H2O2 by redox proteomics approaches (Aim 3). Finally, we will investigate the contribution of Duox1 to epithelial repair in a model of epithelial injury using naphthalene, and in a mouse model of allergic airway inflammation (Aim 4). Collectively, these studies will provide important new insights into the epithelial biology of Duox1, and will establish the potential contribution of Duox in airway remodeling during chronic airway diseases such as asthma. PUBLIC HEALTH RELEVANCE. The airway epithelium is in continuous contact with the environment and is critical in lung defense against inhaled toxins and microbial organisms. In chronic airway diseases such as asthma, the airway epithelium is injured and mechanisms that stimulate epithelial cell growth and repair are activated. Recent studies have identified the presence of an oxidant-producing enzyme, Duox1, within the airway epithelium, which may contribute to airway host defense, similar to recent enzymes in phagocytes. However, our recent studies have also demonstrated that Duox contributes to epithelial repair processes after injury. Thus, although oxidative stress is believed to contribute to tissue damage during disease, low levels of oxidant production by epithelial Duox1 may be beneficial in maintaining airway epithelial barrier integrity. The goal of this project is to investigate the molecular mechanisms by which Duox1 activation mediates epithelial repair processes, and how cellular oxidants produced by Duox1 contribute to this. Secondly, we will investigate the importance of Duox1 in epithelial repair in in vivo models of epithelial injury and allergic airway disease such as asthma. Collectively, these studies will further our understanding of the biological roles of airway Duox1, and its potential importance in chronic airway diseases such as asthma.

描述（由申请人提供）：最近的研究表明，气道内存在新的NADPH氧化酶（Nox）同系物，与吞噬细胞gp 91 phox（Nox 2）具有同源性，负责响应各种炎症或环境刺激而产生H2 O2。这些氮氧化物同系物，称为双氧化酶（Duox），存在两种亚型，其中Duox 1主要在气管支气管上皮细胞中表达，而Duox 2已在唾液腺或粘膜下腺中检测到。除了在气道宿主防御中的假定作用外，最近的研究表明气道上皮Duox 1的替代功能，包括通过促进生长因子、金属蛋白酶和细胞因子的产生来调节上皮H+转运和参与上皮对损伤的反应，以及刺激上皮细胞迁移和修复。我们最近的研究表明，Duox介导的H2 O2的生产在气管支气管上皮细胞响应机械损伤，这是介导的细胞释放的ATP和刺激的嘌呤能P2受体在上皮表面。此外，发现上皮细胞迁移和伤口修复通过ATP介导的促分裂原活化蛋白激酶（MAPK）途径的活化和包括基质金属蛋白酶（MMP）-9的金属蛋白酶的活化介导，通过涉及Duox 1的机制。因此，我们假设Duox 1通过刺激上皮细胞损伤后的修复过程、上皮细胞表面的局部氧化事件和/或氧化还原依赖性细胞信号通路的激活，来维持气道上皮屏障的完整性。此外，根据最近的观察，Th 2细胞因子（IL-13，IL-4）可以诱导上皮Duox 1的表达，肺Duox 1的表达显着增加，在小鼠模型的过敏性气道炎症，我们建议，夸大或持续Duox 1激活可能有助于慢性伤口反应和气道重塑，如在慢性哮喘中观察到的。本提案的主要目的是确定Duox 1激活介导上皮细胞迁移和修复的体外机制，并建立Duox 1对气道上皮修复和重塑的体内贡献。我们将确定细胞外或细胞内H2 O2的产生和/或局部pH值的变化和H+转运对Duox 1介导的上皮细胞迁移的贡献（目标1），确定Duox 1依赖的MAPK激活和生长因子/MMP激活（目标2）的机制，并通过氧化还原蛋白质组学方法表征Duox 1衍生的H2 O2的细胞外和细胞氧化还原敏感性靶点（目标3）。最后，我们将研究Duox 1在使用萘的上皮损伤模型和过敏性气道炎症小鼠模型中对上皮修复的贡献（目的4）。总的来说，这些研究将为Duox 1的上皮生物学提供重要的新见解，并将确定Duox在慢性气道疾病（如哮喘）期间气道重塑中的潜在贡献。公共卫生相关性。气道上皮与环境持续接触，在肺防御吸入毒素和微生物有机体方面至关重要。在慢性气道疾病如哮喘中，气道上皮细胞受损，刺激上皮细胞生长和修复的机制被激活。最近的研究已经确定了氧化剂产生酶Duox 1的存在，在气道上皮细胞，这可能有助于气道宿主防御，类似于最近的酶在吞噬细胞。然而，我们最近的研究也表明，Duox有助于损伤后的上皮修复过程。因此，虽然氧化应激被认为有助于疾病期间的组织损伤，但上皮Duox 1产生的低水平氧化剂可能有利于维持气道上皮屏障的完整性。该项目的目标是研究Duox 1激活介导上皮修复过程的分子机制，以及Duox 1产生的细胞氧化剂如何对此做出贡献。其次，我们将在上皮损伤和过敏性气道疾病（如哮喘）的体内模型中研究Duox 1在上皮修复中的重要性。总的来说，这些研究将进一步加深我们对气道Duox 1的生物学作用及其在慢性气道疾病（如哮喘）中的潜在重要性的理解。