RT Journal Article ID 13a8c1ac601fd48b A1 Liu, Li A1 Carron, Benjamin A1 Yee, Herman T. A1 Yie, Ting-An A1 Hajjou, Mustapha A1 Rom, William N. T1 Wnt Pathway in Pulmonary Fibrosis in the Bleomycin Mouse Model JF Journal of Environmental Pathology, Toxicology and Oncology JO JEP(T) YR 2009 FD 2009-10-05 VO 28 IS 2 SP 99 OP 108 K1 pulmonary fibrosis K1 beta-catenin K1 Wnt pathway AB Background: The Wnt/β-catenin signaling pathway plays an important role in regulating cellular differentiation, proliferation, and polarity. Methods: We used bleomycin to induce lung fibrosis in a transgenic Wnt reporter mouse to characterize the expression pattern of cyclin D1, MMP-7, and TGF-β in conjunction with the Wnt/β-catenin signaling pathway. LacZ expression reveals the Wnt/β-catenin signaling pathway through the activated (nuclear) β-catenin and coactivation of LEF/TCF transcription factors. X-gal staining and immunohistochemical staining of β-catenin, cyclin D1, MMP-7, and TGF-β were assessed after bleomycin administration. Results: We observed LacZ expression in bronchiolar proliferative lesions and the epithelium in remodeled cystic and fibrotic areas at both 1 and 3 weeks. Nuclear β-catenin staining was prominent in epithelial cells of remodeled and fibrotic areas at 3 weeks. MMP-7 was faint in basement membranes of airways and matrix zones in fibrotic areas at 3 weeks. Cyclin D1 was observed in alveolar macrophages (AM), alveolar epithelium, and fibrotic areas consistent with rapid cell turnover in these areas at both 1 and 3 weeks. TGF-β was faintly staining in alveolar macrophages and epithelial cells at 3 weeks. Conclusion: The Wnt/β-catenin pathway is activated in bleomycin-induced lung fibrosis, and downstream genes were localized in AM, alveolar epithelium, and interstitium. PB Begell House LK https://www.dl.begellhouse.com/journals/0ff459a57a4c08d0,5b2ee8f13327d597,13a8c1ac601fd48b.html