Sulforaphane attenuates pulmonary fibrosis by inhibiting the epithelial-mesenchymal transition

• Published in: BMC pharmacology & toxicology Vol. 19; no. 1; pp. 13 - 10
• Main Authors: Kyung, Sun Young, Kim, Dae Young, Yoon, Jin Young, Son, Eun Suk, Kim, Yu Jin, Park, Jeong Woong, Jeong, Sung Hwan
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 02.04.2018; BioMed Central; BMC
• Subjects: Analysis; Animals; Bleomycin; Bone morphogenetic proteins; Cell Line; Collagen; Collagen Type I - metabolism; Collagen Type IV - metabolism; DNA binding proteins; Epithelial-mesenchymal transition; Epithelial-Mesenchymal Transition - drug effects; Fibronectins; Humans; Idiopathic pulmonary fibrosis; Isothiocyanates - pharmacology; Isothiocyanates - therapeutic use; Lung - drug effects; Lung - metabolism; Lung - pathology; Male; Mice, Inbred C57BL; Muscle proteins; Pulmonary fibrosis; Pulmonary Fibrosis - chemically induced; Pulmonary Fibrosis - drug therapy; Pulmonary Fibrosis - metabolism; Pulmonary Fibrosis - pathology; Respiratory tract diseases; Smad2 Protein - metabolism; Smad3 Protein - metabolism; Stem cells; Sulforaphane; Transforming Growth Factor beta - metabolism; Transforming growth factors; Epithelial-mesenchymal transition; Bleomycin; Idiopathic pulmonary fibrosis; Sulforaphane
• ISSN: 2050-6511; 2050-6511
• DOI: 10.1186/s40360-018-0204-7

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease with no effective treatment. The epithelial-mesenchymal transition (EMT) is a critical stage during the development of fibrosis. To assess the effect of sulforaphane (SFN) on the EMT and fibrosis using an in vitro transforming growth factor (TGF)-β1-induced model and an in vivo bleomycin (BLM)-induced model. In vitro studies, cell viability, and cytotoxicity were measured using a Cell Counting Kit-8. The functional TGF-β1-induced EMT and fibrosis were assessed using western blotting and a quantitative real-time polymerase chain reaction. The lungs were analyzed histopathologically in vivo using hematoxylin and eosin and Masson's trichrome staining. The BLM-induced fibrosis was characterized by western blotting and immunohistochemical analyses for fibronectin, TGF-β1, E-cadherin (E-cad), and α-smooth muscle actin (SMA) in lung tissues. SFN reversed mesenchymal-like changes induced by TGF-β1 and restored cells to their epithelial-like morphology. The results confirmed that the expression of the epithelial marker, E-cadherin, increased after SFN treatment, while expression of the mesenchymal markers, N-cadherin, vimentin, and α-SMA decreased in A549 cells after SFN treatment. In addition, SFN inhibited TGF-β1-induced mRNA expression of the EMT-related transcription factors, Slug, Snail, and Twist. The SFN treatment attenuated TGF-β1-induced expression of fibrosis-related proteins, such as fibronection, collagen I, collagen IV, and α-SMA in MRC-5 cells. Furthermore, SFN reduced the TGF-β1-induced phosphorylation of SMAD2/3 protein in A549 cells and MRC-5 cells. BLM induced fibrosis in mouse lungs that was also attenuated by SFN treatment, and SFN treatment decreased BLM-induced fibronectin expression, TGF-β1 expression, and the levels of collagen I in the lungs of mice. SFN showed a significant anti-fibrotic effect in TGF-β-treated cell lines and BLM-induced fibrosis in mice. These findings showed that SFN has anti-fibrotic activity that may be considered in the treatment of IPF.