title: Bronchial epithelium-derived IL-8 and RANTES increased bronchial smooth muscle cell migration and proliferation by Krüppel-like factor 5 in areca nut-mediated airway remodeling.
abstract: This study is first to analyze the inflammatory cytokines, produced by the bronchial epithelium after exposure to areca nut extract (ANE), which contribute to airway remodeling by increasing human bronchial smooth muscle cells (BSMC) migration and proliferation. We treated human bronchial epithelial cell lines BEAS-2B and HBE135-E6E7 (HBE) with ANE, saliva-reacted ANE (sANE), and the areca alkaloids arecoline and then harvested the conditioned medium (CM) that was added to BSMC. Exposure of BEAS-2B and HBE to ANE, sANE, and arecoline increased interleukin 8 (IL-8) and Regulated upon Activation, Normal T-cell Expressed, and Secreted (RANTES) production. Cultures of BSMC with ANE-, sANE-, and arecoline-BEAS-2B-CM and -HBE-CM increased BSMC proliferation and migration. Induction of BSMC proliferation and migration by sANE-BEAS-2B-CM and -HBE-CM was associated with increased phosphorylation of Raf, MEK1/2, and extracellular signal regulated kinase (ERK)1/2 and the upregulation of krüppel-like factor 5 (KLF5), cyclin D, and integrin-linked kinase. Blocking ERK1/2 by a specific inhibitor significantly decreased BSMC proliferation and migration by inhibiting KLF5 enhancement. KLF5 knockdown also decreased sANE-BEAS-2B-CM, sANE-HBE-CM, and recombinant human interleukin 8/recombinant human RANTES-mediated BSMC proliferation and migration, suggesting that KLF5 was involved in the regulation of BSMC proliferation and migration. Our study suggests that inhibition of IL-8 and RANTES or IL-8/RANTES-mediated mitogen-activated protein kinase/KLF5 signaling is an attractive therapeutic target for areca nut-induced asthma.
authors.affiliation: Institute of Clinical Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan.
authors.forename: Po-Lin
authors.initials: PL
authors.lastname: Kuo
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Hsu
authors.forename: Ming-Shyan
authors.initials: MS
authors.lastname: Huang
authors.forename: Shang-Lun
authors.initials: SL
authors.lastname: Chiang
authors.forename: Ying-Chin
authors.initials: YC
authors.lastname: Ko
mesh_terms: D001114:Areca; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D018946:Chemokine CCL5 / Q000494:pharmacology*; D017077:Culture Media, Conditioned; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology*; D051741:Kruppel-Like Transcription Factors; D009130:Muscle, Smooth / Q000166:cytology*
chemical_list: C483024:CCL5 protein, human; D018946:Chemokine CCL5; D017077:Culture Media, Conditioned; D016209:Interleukin-8; C492214:KLF5 protein, human; D051741:Kruppel-Like Transcription Factors