title: Bleomycin-induced epithelial-mesenchymal transition in sclerotic skin of mice: possible role of oxidative stress in the pathogenesis.
abstract: Epithelial-mesenchymal transition (EMT) derived myofibroblasts are partly responsible for the increased collagen synthesis and deposition that occur in tissue fibrosis; however EMT occurrence in skin fibrosis and its mechanism remain unknown. The aim of this study was to investigate whether epithelial cells undergo EMT and determine the role of oxidative stress in this process. BALB/c mice were subcutaneously injected with bleomycin (BLM) or phosphate buffer saline (PBS) into the shaved back daily for 2, 3, and 4weeks. Skin collagen deposition was evaluated by histopathology and Western blotting. EMT characteristics in the skin were determined by histopathology and immunofluorescent staining for E-cadherin and vimentin, which were further evaluated by Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR). To investigate the role of oxidative stress in EMT, the antioxidant N-acetylcysteine (NAC) was intraperitoneally (100mg/kg body weight/day) injected daily for 3weeks. The epithelial suprabasal cells were detached from the basement membrane zone (BMZ) in the sclerotic skin treated with BLM. Immunofluorescent staining indicated vimentin-positive epithelial cells frequently occurring in the thickened epidermis of BLM-treated mice. Western blotting and RT-PCR showed that the expression of E-cadherin was significantly decreased but that of vimentin significantly increased in the skin treated with BLM. NAC attenuated BLM induced oxidative damage, changes in E-cadherin and vimentin expressions and collagen deposition in the sclerotic skin of mice. This study provides the first evidence that BLM induces the EMT of the epithelial cells superficial to the basement membrane zone in the skin fibrosis. Oxidative stress may contribute, at least in part, to BLM induced EMT and skin fibrosis in mice.
authors.affiliation: Institute of Dermatology, the First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, China; Department of Occupational Health and Environmental Health, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China. Electronic address: zhouchengfan@sohu.com.
authors.forename: Cheng-Fan
authors.initials: CF
authors.lastname: Zhou
authors.affiliation: Department of Emergency Medicine & Critical Care Medicine, the First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, China.
authors.forename: Deng-Chuan
authors.initials: DC
authors.lastname: Zhou
authors.affiliation: Department of Occupational Health and Environmental Health, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China.
authors.forename: Jia-Xiang
authors.initials: JX
authors.lastname: Zhang
authors.affiliation: Department of Occupational Health and Environmental Health, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Occupational Health and Environmental Health, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China.
authors.forename: Wan-Sheng
authors.initials: WS
authors.lastname: Cha
authors.affiliation: Department of Biochemistry and Physiology, Faculty of Health and Medical Sciences, University of Surrey, UK.
authors.forename: Chang-Hao
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Institute of Dermatology, the First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, China; Department of Occupational Health and Environmental Health, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China. Electronic address: zqxing@yeah.net.
authors.forename: Qi-Xing
authors.initials: QX
authors.lastname: Zhu
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000633:toxicity*; D001761:Bleomycin / Q000633:toxicity*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D005355:Fibrosis; D051379:Mice; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress / Q000187:drug effects*; D012598:Sclerosis; D012871:Skin Diseases / Q000139:chemically induced* / Q000473:pathology; D013047:Specific Pathogen-Free Organisms
chemical_list: D000903:Antibiotics, Antineoplastic; D001761:Bleomycin
keywords: Bleomycin; Epithelial–mesenchymal transition; Mouse model; N-acetylcysteine; Oxidative stress; Skin fibrosis