TY - JOUR AB - Pulmonary fibrosis (PF) is a chronic lung disease. The transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway plays an important role in the pathogenesis of pulmonary fibrosis. Bone marrow-derived mesenchymal stem cells (BMSCs) have been shown to be a modulator of the molecular aspects of the fibrosis pathway. However, it is still unknown as to whether the conditioned medium from BMSCs (BMSCs-CM) inhibits the epithelial-mesenchymal transition (EMT) process. This study confirmed the hypothesis that BMSCs-CM exerts an anti-fibrotic effect on human type II alveolar epithelial cells (A549) by suppressing the phosphorylation of Smad3. We used the A549 cells in vitro to detect morphological evidence of EMT by phase-contrast microscopy. These cells were randomly divided into 4 groups as follows: the control group, the TGF-β1 group, the SIS3 (specific inhibitor of Smad3) group and the BMSCs-CM group. The immunofluorescence method was used to determined the location of E-cadherin (E-calcium mucins; E-cad), α-smooth muscle actin (α-SMA) and p-Smad3. The expression levels of E-cad, CK8, α-SMA, vimentin, p-Smad3, Snail1, collagen I (COLI) and collagen III (COLIII) were detected by western blot analysis. Following exposure to TGF-β1, the A549 cells displayed a spindle-shaped fibroblast-like morphology. In accordance with these morphological changes, the expression levels of E-cad and CK8 were downregulated, while the expression levels of α-SMA and vimentin were upregulated. Along with this process, the expression levels of p-Smad3, Snail1, COLI and COLIII were increased. However, the cells in the BMSCs-CM group and SIS3 group exhibited a decrease in the levels of α-SMA and vimentin (which had been upregulated by TGF-β1), and an increase in the levels of E-cad and CK8 expression (which had been downregulated by TGF-β1). On the whole, these results indicated that BMSCs-CM suppressed the EMT which might be associated with TGF-β1/Smad3. This study provides the theoretical basis for the research of the mechanisms responsible for pulmonary disease. AD - School of Basic Medical Sciences, North China University of Science and Technology, Tangshan, Hebei 063210, P.R. China Department of Neurosurgery, Tangshan Workers' Hospital, Tangshan, Hebei 063000, P.R. China AU - Wang,Xin AU - Gao,Jun-Ling AU - Zhao,Man-Man AU - Zhu,Hui-Xing AU - Tian,Yan-Xia AU - Li,Ran AU - Jiang,Xiao-Hua AU - Yu,Lei AU - Tian,Jing-Rui AU - Cui,Jian-Zhong DA - 2018/02/01 DO - 10.3892/ijmm.2017.3284 EP - 668 IS - 2 JO - Int J Mol Med KW - bone marrow-derived mesenchymal stem cells conditioned medium epithelial-mesenchymal transition type II alveolar epithelial cells A549 PY - 2018 SN - 1107-3756 1791-244X SP - 659 ST - Therapeutic effects of conditioned medium from bone marrow-derived mesenchymal stem cells on epithelial-mesenchymal transition in A549 cells T2 - International Journal of Molecular Medicine TI - Therapeutic effects of conditioned medium from bone marrow-derived mesenchymal stem cells on epithelial-mesenchymal transition in A549 cells UR - https://doi.org/10.3892/ijmm.2017.3284 VL - 41 ER -