title: Little evidence for epithelial-mesenchymal transition in a murine model of airway fibrosis induced by repeated naphthalene exposure.
abstract: Recent evidence suggests that epithelial-mesenchymal transition (EMT) is involved in the pathogenesis of airway obstructive diseases, such as chronic obstructive pulmonary disease, asthma and bronchiolitis obliterans syndrome after lung transplantation. However, whether EMT occurs in an experimental model of airway fibrosis is not well known. We explored evidence of EMT in a murine model of airway fibrosis induced by repeated exposure to naphthalene. Mice were administered intraperitoneal injections of naphthalene or corn oil vehicle once weekly for 14 consecutive weeks. The animals were sacrificed 5days after the final injection of naphthalene or corn oil vehicle. EMT was evaluated in lung tissue sections using immunohistochemistry and immunofluorescence. Repeated naphthalene exposure induced loss of club cells, hyperplasia of epithelial cells and peribronchial fibrosis. However, we did not find any loss of E-cadherin expression or any acquisition of vimentin, S100A4 or αSMA in epithelial cells in control or naphthalene-exposed mice. These results suggest that EMT does not contribute significantly to naphthalene-induced airway fibrosis in mice.
authors: Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami-machi, Inashiki-gun, Ibaraki 300-0395, Japan. Electronic address: wosamu29@tokyo-med.ac.jp.
authors: Osamu
authors: O
authors: Watanabe
authors: Respiratory Medicine, Institute of Geriatrics Tokyo Women's Medical University, 2-15-1 Shibuya, Shibuya-ku, Tokyo 150-0002, Japan. Electronic address: tsuji.takao@twmu.ac.jp.
authors: Takao
authors: T
authors: Tsuji
authors: Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami-machi, Inashiki-gun, Ibaraki 300-0395, Japan. Electronic address: reo1129@tokyo-med.ac.jp.
authors: Ryota
authors: R
authors: Kikuchi
authors: Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami-machi, Inashiki-gun, Ibaraki 300-0395, Japan. Electronic address: fraser@tokyo-med.ac.jp.
authors: Masayuki
authors: M
authors: Itoh
authors: Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami-machi, Inashiki-gun, Ibaraki 300-0395, Japan. Electronic address: hiroyuki@tokyo-med.ac.jp.
authors: Hiroyuki
authors: H
authors: Nakamura
authors: Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami-machi, Inashiki-gun, Ibaraki 300-0395, Japan. Electronic address: kaoshiba@tokyo-med.ac.jp.
authors: Kazutetsu
authors: K
authors: Aoshiba
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D009281:Naphthalenes / Q000633:toxicity*; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000473:pathology*
chemical_list: D009281:Naphthalenes; C031721:naphthalene
keywords: Airway fibrosis; Chronic obstructive pulmonary disease; Epithelial injury; Epithelial-mesenchymal transition; Naphthalene