Abstract
In the current studies, we examined the ability of human dental follicle cells (DFCs), dental pulp stem cells (DPSCs), and oral mucosal cells (OMCs) to form dentin by analyzing their expression of the odontoblast-specific genes, dentin sialophosphoprotein (DSPP) and dentin sialoprotein (DSP), and the mineralization-associated genes, alkaline phosphatase (ALP) and dentin matrix protein-1 (DMP-1). Phase contrast microscopy showed that DFCs, DPSCs, and OMCs exhibited spindle-shaped and fibroblastic morphologies. Also, more bone nodules were formed in DFCs than in DPSCs, whereas bone nodules were not found in OMCs. Analysis of gene expression by real-time reverse transcriptase-polymerase chain reaction showed a time-dependent increase in the expression of DSPP in differentiating DFCs and DPSCs, but almost no expression in OMCs. The expression of DSPP in DFCs was approximately 4-fold higher than in DPSCs after 15 days in culture, and, almost 6-fold higher after 27 days. In addition, the expression of DSP, DMP-1 and ALP was observed in both DFCs and DPSCs, with a slow increase until 15 days of differentiation, and, after 21 days, there was a rapid increase in the expression of these genes in DFCs. In contrast, expression of these genes was almost undetectable in OMCs and in undifferentiated DFCs, DPSCs and OMCs. These results suggest that, compared to DPSCs, DFCs have a superior capacity for dentin formation and mineralization and that they may be useful for the regeneration of dentin or tooth tissues using tissue engineering technology.
