Hepatocyte Growth Factor Exerts Promoting Functions on Murine Dental Papilla Cells

Hepatocyte growth factor (HGF) is a potent mitogenic and angiogenic factor involved in the development of many tissues including the teeth. We previously reported that dental pulp cells express the HGF receptor c-met and that HGF can enhance cell proliferation and differentiation. The purpose of this study was to determine whether HGF could stimulate proliferation and/or differentiation of murine dental papilla cells (MDPCs). MDPCs were isolated from neonatal mice, and the mitogenic potential of HGF on MDPCs was measured by 3-(4, 5-dimethyl-thyazol-2-yl)-2, 5-diphenyltetrazolium and flow cytometry. Differentiation of MDPCs in the presence of HGF was characterized by mineralization assay, alkaline phosphatase (ALP) activity and reverse-transcription polymerase chain reaction. We reported that MDPCs expressed both HGF and c-met and that HGF enhanced proliferation of MDPCs by concentrations ranging from 5 ng/mL to 20 ng/mL, with 10 ng/mL as the optimal concentration (p < 0.05). HGF prolonged S phase and shortened G1 phase of MDPCs, increased ALP activity significantly over the control (p < 0.05), and enhanced the formation of mineral nodules. ALP, dentin sialophosphoprotein, and dentin matrix protein-1 expression were significantly increased in the presence of HGF (p < 0.05), as were the expression of Msx1, Runx2, and Pax9. Our data suggest that HGF plays an important role in tooth development, by promoting the proliferation and differentiation of MDPCs. (J Endod 2009,-35:382-388)