Transforming Growth Factor-β1 Enhances Mesenchymal Characteristics of Buffalo (Bubalus bubalis) Bone Marrow-Derived Mesenchymal Stem Cells

Bone marrow-derived mesenchymal stem cells (BMSCs) from livestock are valuable resources for animal reproduction and veterinary therapeutics. Previous studies have shown that BMSCs were prone to malignant transformation of mesenchymal-to-epithelial transition in vitro, which can cause many barriers to further application of BMSCs. The transforming growth factor β (TGF-β) signaling pathway has been widely studied as the most important signaling pathway involved in regulating mesenchymal features of BMSCs. However, the effects of the TGF-β signaling pathway on mesenchymal characteristics of buffalo BMSCs (bBMSCs) remain unclear. In the present study, the impacts of the growth factor, TGF-β1, on cell proliferation, apoptosis, migration, and karyotype of bBMSCs were tested. Besides, the effects of TGF-β1 on pluripotency, mesenchymal markers, and epithelial-to-mesenchymal transition (EMT)-related gene expression of bBMSCs were also examined. Results showed that the suitable concentration and time of TGF-β1 treatment (2 ng/mL and 24 hours) promoted cell proliferation and significantly reduced cell apoptosis (p < 0.05) in bBMSCs. The cell migration capacity and normal karyotype rate of bBMSCs were significantly (p < 0.05) improved under TGF-β1 treatment. The expression levels of pluripotency-related genes (Sox2 and Nanog) and mesenchymal markers (N-cadherin and Fn1) were significantly (p < 0.05) up-regulated under TGF-β1 treatment. Furthermore, TGF-β1 activated the EMT process, thereby contributing to significantly enhancing the expression levels of EMT-related genes (Snail and Slug) (p < 0.05), which in turn improved maintenance of the mesenchymal nature in bBMSCs. Finally, bBMSCs underwent self-transformation more easily and efficiently and exhibited more characteristics of mesenchymal stem cells under TGF-β1 treatment. This study provides theoretical guidance for elucidating the detailed mechanism of the TGF-β signaling pathway in mesenchymal feature maintenance of bBMSCs and is of significance to establish a stable culture system of bBMSCs.