氟化物作用下体外培养人牙胚内釉上皮细胞中Smad1、5表达的变化

Smad1,5 expression and modulation in inner enamel epithelia of human teeth germs cultured in vitro treated by fluoride

目的观察不同浓度的氟化物对体外培养的人牙胚内釉上皮细胞中Smad1、5表达的影响,从细胞内信号转导水平观察氟对骨形成蛋白(BMP)信号转导的影响。方法Trowell法体外培养人牙胚,分别用10mg/L和25mg/L的氟化物刺激培养的牙胚,免疫组化观察结果。结果经图像分析显示,10mg/L组和25mg/L组从第4天开始,内釉上皮细胞中Smad1、5的表达均低于对照组。结论氟化物能抑制体外培养的人牙胚内釉上皮细胞中Smad1、5表达。提示氟可能通过抑制Smad1、5分子干扰上皮和间充质之间BMP正常的信号转导,进而使釉质的分化发育受到影响,可能是氟斑牙发生的细胞内机制之一。

Objective To investigate Smad1,5 expression and modulation in inner enamel epithelia of human teeth germs cultured in vitro treated by different densities of fluoride and to explore the probable mechanisms inside the cells of dental fluorosis. Methods Human teeth germs were cultured in different densities （10mg/L and 25mg/L） of fluoride in vitro with Trowell＇s method. The result was observed by immnnohistochemical staining. Results Both Smadl and 5 expressions reduced from the fourth day at 10mg/L and 25mg/L levels of fluorine ion. Statistic tests showed there were significant differences between the two groups （the experimental group and the control group）. But on the twelfth day at 25mg/L level, no significant differences were observed. Conclusion Fluoride may inhibit the expression of Smadl, 5 in inner enamel epithelia of human teeth germs cultured in vitro. That suggests fluoride may disturb the signals of BMP transducing between the epithelia and mesenchyma in this way, and inhibit the differentiation and function of the tooth-forming cells.