Effects of FGF2 and TGFβ1 on the differentiation of human dental pulp stem cells in vitro

Two crucial growth factors, FGF2 and TGFβ1, were investigated in this study to determine their inductive effects on the odontoblastic differentiation of human dental pulp stem cells (DPSCs) in vitro. DPSCs were isolated by immunomagnetic bead selection using the STRO-1 antibody, and then co-cultured respectively with FGF2, TGFβ1 and FGF2 + TGFβ1. The results showed that FGF2 can exert a significant effect on the cell proliferation, while TGFβ1 or FGF2 + TGFβ1 can initiate an odontoblast-like differentiation of DPSCs. Moreover, FGF2 can synergistically upregulate the effects of TGFβ1 on the odontoblastic differentiation of DPSCs, as indicated by the increased alkaline phosphatase activity, the polarized cell appearance and secretary ultrastructural features, the formation of mineralized nodules and the gene/protein expression of dentin sialoprotein and dentin matrix protein-1. Together, FGF2 acted primarily on the cell proliferation, while TGFβ1 and FGF2 + TGFβ1 mainly stimulated the odontoblastic differentiation of DPSCs. This study provides interesting progress in the odontoblastic differentiation of DPSCs induced by FGF2 and TGFβ1.