Notch配体Delta1对人牙髓干细胞分化的影响

目的:探讨Notch配体Delta1对体外人牙髓干细胞(dentalpulpstemcells,DPSCs)向成牙本质细胞分化能力的影响。方法:利用逆转录病毒载体建立高表达人Delta1基因的人牙髓干细胞系;实验分三组,正常牙髓干细胞组、转导细胞组及混合组(正常与转导细胞比例为100∶1),分别进行体外分化诱导。倒置显微镜观测各组细胞各生长期出现的时间;VonKossa染色计数各组形成钙化结节数;Westernblot法检测各组细胞牙本质涎磷蛋白表达。结果:与正常牙髓干细胞相比,转导细胞各生长期出现时间明显提前,形成的钙化细胞结节数目显著增加,牙本质涎磷蛋白表达显著升高。结论:Delta1基因转导牙髓干细胞仍保持了体外向成牙本质细胞分化的能力;Notch-Delta1信号与分化诱导因子协同作用可促进人牙髓干细胞向成牙本质细胞分化。

Effects of Notch ligand Delta1 on the differentiation of human dental pulp stem cells

AIM:To investigate the effects of Notch ligand Delta1 on the differentiation of human dental pulp stem cells (DPSCs) into odontoblasts in vitro.METHODS:DPSCs were transduced by retrovirus supernatant containing Delta1-EGFP,and selected by puromycin to obtain positive cell clones with high expression of Delta1.The experiments were divided into three groups:wild type DPSCs group as control,Delta1 transduced DPSCs group and the mixing group with a ratio of 1 transduced DPSCs to 100 wild type DPSCs.All groups were cultured in an odonto-inductive medium.The growth timing of each group was observed under phase control microscope,and the number of mineralization nodules was counted after stained by Von Kossa assay.Expression of dentin sialophosphoprotein(DSPP)was detected by western blot.RESULTS:Comparing with wild type DPSCs,the transduced DPSCs could form more calcified cell nodules ahead of schedule. DSPP expression of calcified transduced cells was significantly increased.CONCLUSION:Delta1 transduced DPSCs remain their capability of differentiating into odontoblasts in vitro.Notch-Delta1 signaling could stimulate the differentiation of DPSCs with the coexistence of differentiation-inductive molecules.