HIR-99021促进诱导人表皮干细胞牙向分化

Human keratinocyte stem cells (hKSCs) can be used as epithelial adult stem cells in tooth regeneration. But the tooth formation rate from such cells is relatively low. In this study, we treated hKSCs with small molecules CHIR-99021 to activate the Wnt/β-catenin pathway before we recombined the hKSCs with mouse embryonic dental mesenchyme possessing odontogenic potential. Histology and immunohistochemistry staining were used to detect the chimeric tooth. The results showed that the efficiency of tooth formation(tooth formation rate) of the chimeric tooth treated with FGF8 is 27.80%, and among those formed teeth, the efficiency of hKSCs differentiation into ameloblasts (ameloblasts differentiation rate) is 40.00%. Then CHIR-99021 could improve the ameloblasts differentiation rate to 100%. The synergistic effect of CHIR-99021 and FGF8 can increase the tooth formation rate to 40.00%, and ameloblasts differentiation rate to 75.00%. Further research found that CHIR-99021 could activate the Wnt/β-catenin signaling for hKSCs, and increase protein and mRNA levels of FGF8. These results indicated that CHIR-99021 could activate the Wnt/β-catenin signaling for hKSCs and simultaneously enhance the expression of FGF8, which increase the induction of hKSCs into ameloblasts. This study provides relevant experimental data for tooth regeneration which use hKSCs as a source of human epithelial stem cells.