title: Arylhydrocarbon receptor (AhR) activation in airway epithelial cells induces MUC5AC via reactive oxygen species (ROS) production.
abstract: The dioxins and dioxin-like compounds in cigarette smoke regulate various immunological responses via the arylhydrocarbon receptor (AhR). These environmental toxicants are known to cause bronchitis, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. Recent studies have demonstrated that AhR activation upregulates the expression of mucin 5AC, oligomeric mucus/gel-forming (MUC5AC) in the airway epithelial cell line. However, the mechanism for the production of mucin has not been clarified. In this study, we investigated the role and pathway of AhR in airway epithelial cells by using selective agonists and antagonists. After stimulation with or without benzopyrene (B[a]P), an AhR agonist, MUC5AC expression was measured by real-time RT-PCR. The mechanism of AhR-induced MUC5AC expression in airway epithelial cells was studied in terms of the production of cytokine and reactive oxygen species (ROS). Treatment with B[a]P increased ROS generation in NCI-H₂₉₂ cells. Furthermore, B[a]P-induced MUC5AC upregulation and mucin production were inhibited by AhR siRNA or the use of an antioxidative agent. These results suggest that the AhR-induced increase of mucin production is partially mediated by ROS generation. An antioxidant therapy approach may help to cure AhR-induced mucus hypersecretory diseases.
authors: Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. allheart@dermatol.med.kyushu-u.ac.jp
authors: Takahito
authors: T
authors: Chiba
authors: Hiroshi
authors: H
authors: Uchi
authors: Gaku
authors: G
authors: Tsuji
authors: Hisaki
authors: H
authors: Gondo
authors: Yoichi
authors: Y
authors: Moroi
authors: Masutaka
authors: M
authors: Furue
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D001564:Benzo(a)pyrene / Q000633:toxicity; D001980:Bronchi / Q000378:metabolism*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D055271:Mucin 5AC / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species / Q000378:metabolism*; D018336:Receptors, Aryl Hydrocarbon / Q000502:physiology*
chemical_list: C524678:MUC5AC protein, human; D055271:Mucin 5AC; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D018336:Receptors, Aryl Hydrocarbon; D001564:Benzo(a)pyrene; D000111:Acetylcysteine