Effects Of Berberine On TGF - β1 - Induced Epithelial - Mesenchymal Transition And MRC - 5 Cell Transdifferentiation And Cell Signaling Pathway In A549 Cells

Objective The aim of this study is to investigate the effects of berberine (BBR) on transforming growth factor-β1 (TGF-β1) induced epithelial-mesenchymal transition (EMT) in human lung cancer A549 cells and transdifferentiation in human fetal lung fibroblast MRC-5 cells as well as the phosphorylation level of proteins which involved in p38 MAPK/PI3K/ERK1/2/JNK/Akt signaling pathway in both the cell lines.Methods Suitable concentrations of BBR for in vitro treatment in this study were chosen according to the inhibition profile of cell proliferation measured by MTT assay in A549 or MRC-5 cells. The expression levels of cell EMT or transdifferentiation related biomarkers such as E-cadherin, a-smooth muscle-actin (a-SMA) and fibronectin (FN) were detected by Western blot and an effective concentration of TGF-β1 for cell EMT or transdifferentiation inducing was selected. The expression of an extracelluar matrix protein, hydroxyproline, was analysed by colorimetric method as well as the expression of E-cadherin, a-SMA, FN, and the phosphorylation level of MAPK signaling related molecules such as p38, ERK1/2 and JNK, Akt signaling related molecules such as p-Akt and Snail were determined by Western blot to evaluate the inhibitory effects of BBR on TGF-β1 induced EMT or transdifferentiation in A549 or MRC-5 cells. The transcription levels of EMT and transdifferentiation related biomarkers such as E-cadherin,a-SMA and FN in both the cells were detected by Real-time PCR.Results According to the results of MTT assay in both the cells, three concentrations of BBR (20、40、80μmol/L) were chosen for cell treatments in this study. Western blot analysis indicated that 2 ng/mL of TGF-β1 could effectively induce EMT or transdifferentiation in A549 or MRC-5 cells and the concentration was used for the following treatments in this study. Comparing with the single TGF-β1 treated A549 cells, the A549 cells pretreated with BBR showed lower level of hydroxyproline in cell supernatant. Western blot analysis indicated that the expression of FN, snail and phosphorylation level of ERK1/2 could be significantly suppressed by pretreatment of BBR in the TGF-β1 induced A549 cells. On the contrary, the phosphorylation level of Akt could be significantly promoted by pretreatment of BBR in the TGF-β1 induced A549 cells. In MRC-5 cells, comparing with the single TGF-β1 treated cells, the cells pretreated with BBR showed lower level of hydroxyproline in cell supernatant. Western blot analysis indicated that the expression of a-SMA and FN as well as the phosphorylation level of p38, ERK1/2, JNK, Akt and Snail could be significantly suppressed by preatment of BBR in the TGF-β1 induced MRC-5 cells.Conclusion Pretreatment with BBR can suppress the TGF-β1 induced EMT and down-regulate the phosphorylation level of ERK1/2, snail and up-regulate the phosphorylation level of Akt in A549 cells. Pretreatment with BBR can suppress the TGF-β1 induced transdifferentiation and down-regulate the phosphorylation level of p38, ERK1/2, JNK, Akt as well as the expression of Snail in MRC-5 cells.