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，在呼吸道内存在新的NADPH氧化酶(NOx)同源物，与吞噬细胞gp91Phox(NOX2)同源，负责顶端上皮细胞在各种炎症或环境刺激下产生过氧化氢。这些NOx同源物被称为双重氧化酶(DUOX)，以两种亚型存在，其中Duox1主要在气管、支气管上皮中表达，而DUOX2在唾液或粘膜下腺中也有表达。除了在呼吸道宿主防御中的假设作用外，最近的研究表明，气道上皮细胞Duox1还有其他功能，包括调节上皮细胞H+转运，通过促进生长因子、金属蛋白酶和细胞因子的产生，以及刺激上皮细胞迁移和修复，参与上皮细胞对损伤的反应。我们最近的研究表明，机械损伤时，DUOX介导的气管-支气管壁上皮细胞产生H_2O_2，这是通过细胞释放ATP和刺激上皮表面的嘌呤能P2受体来介导的。此外，细胞迁移和创伤修复被发现是由ATP介导的丝裂原活化蛋白激酶(MAPK)通路的激活和包括基质金属蛋白酶(MMP)-9在内的金属蛋白酶的激活所介导的，涉及Duox1的机制。因此，我们假设Duox1通过刺激损伤反应中的上皮修复过程、通过上皮表面局部的氧化事件和/或通过激活依赖氧化还原的细胞信号通路来维持呼吸道上皮屏障的完整性。此外，根据最近观察到Th2细胞因子(IL-13、IL-4)可以诱导上皮细胞Duox1的表达，并且在过敏性气道炎小鼠模型中肺Duox1的表达显著增加，我们认为过度或持续的Duox1激活可能参与了慢性创伤反应和气道重塑，正如在慢性哮喘中所观察到的那样。本研究的主要目的是确定Duox1激活在体外介导上皮细胞迁移和修复的机制，并在体内确定Duox1在呼吸道上皮修复和重塑中的作用。我们将确定细胞外或细胞内过氧化氢的产生和/或局部的pH变化和H+转运对Duox1介导的上皮细胞迁移的贡献(Aim 1)，确定参与Duox1依赖的MAPK激活和生长因子/MMP激活的机制(Aim 2)，并用氧化还原蛋白质组学方法表征细胞外和细胞内氧化还原敏感的Duox1来源的过氧化氢的靶点(Aim 3)。最后，我们将在使用萘的上皮损伤模型和过敏性呼吸道炎症的小鼠模型中研究Duox1在上皮修复中的作用(目标4)。总之，这些研究将为Duox1的上皮生物学提供重要的新见解，并将确立DUOX在哮喘等慢性呼吸道疾病中的潜在贡献。与公共卫生相关。呼吸道上皮与环境持续接触，在肺部抵御吸入毒素和微生物方面至关重要。在哮喘等慢性呼吸道疾病中，呼吸道上皮受到损伤，刺激上皮细胞生长和修复的机制被激活。最近的研究发现，在呼吸道上皮细胞中存在一种氧化剂产生酶Duox1，它可能有助于呼吸道宿主防御，类似于最近吞噬细胞中的酶。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，尽管氧化应激被认为是疾病期间组织损伤的原因，但上皮Duox1产生的低水平氧化剂可能有助于维持呼吸道上皮屏障的完整性。本项目的目标是研究Duox1激活介导上皮修复过程的分子机制，以及Duox1产生的细胞氧化剂如何参与这一过程。其次，我们将在上皮损伤和过敏性呼吸道疾病(如哮喘)的体内模型中探讨Duox1在上皮修复中的重要性。总而言之，这些研究将进一步加深我们对气道Duox1的生物学作用的理解，以及它在哮喘等慢性呼吸道疾病中的潜在重要性。