Study on the influence of Wnt3a on osteogenetic differentiation ability of dental pulp stem cells induced by mineralizing medium

Objective To investigate the effects of Wnt3a protein on proliferation and osteogenic differentiation of human dental pulp stem cells(DPSC). Methods Intact human permanent teeth extracted for orthodontic reasons were collected and used as study models. The biological effects of Wnt3a on DPSC were investigated using methyl thiazolyl tetrazolium(MTT), alkaline phosphatase(ALP) activity assay, alizarin red S staining and realtime fluorescence quantitative PCR. Osteogenic-related gene expression of induced DPSC was examinedby using tests of bone sialoprotein(BSP), osteocalcin(OCN), collagen type Ⅰ (COL-Ⅰ) and Runt-related transcription factor 2(RUNX-2). Results Wnt3a proteininduced an increase of cell growth and treatment of DPSC with Wnt3a induced a highest increase in cell growth at the concentration of 5 μg/L. 5 μg/L Wnt3a proteins combined with the osteogenic medium treatment caused up-regulated osteogenic differentiation, ALP activity and express of osteogenic-related genes of DPSC, and the ALP activity(0.47±0.04) was significantly stronger than the other groups(osteogenic medium: 0.39±0.05; 20 μg/L: 0.34±0.03; 50 μg/L: 0.27±0.07; 100 μg/L: 0.20±0.03). Conclusions Exogenous Wnt3a protein treatment on DPSC could affect the proliferation and osteogenic differentiation. Key words: Wnt proteins; Cell proliferation; Dental pulp stem cells; Osteogenesis