氟化物作用下体外培养人牙胚内釉上皮细胞中Smad4表达的变化

Smad4 expression and modulation in inner enamel epithelium of human tooth germ 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Smad4表达的影响 ,从细胞内信号转导水平探讨发生氟牙症可能的细胞内机制。方法 :Trowell法体外培养人牙胚 ,用 10mg/L和2 5mg/L的氟分别刺激培养的牙胚 ,免疫组化观察结果。结果 :免疫组化结果经图像分析显示 10mg/L组从第8天 ,2 5mg/L组从第 4天开始内釉上皮细胞中Smad4的表达低于对照组。结论 :观察到 ,氟化物能抑制体外培养的人牙胚内釉上皮细胞中Smad4表达。提示 :氟可能通过抑制Smad4分子来干扰上皮和间充质之间正常的信号转导 ,进而使釉质的分化发育受到影响。这有可能即是氟牙症发生的细胞内机制之一。

AIM:To investigate Smad4 expression and modulation in inner enamel epithelium of human tooth Germ cultured in vitro treated by different densities of fluoride and to explore the probable mechanism inside cells of dental fluorosis.METHODS:Human teeth germs were cultured in different densities (10 mg/L and 25 mg/L) of fluoride in vitro with Trowell′s method. To observe the result by immunohistochemical staining.RESULTS:Smad4 expression reduced from the eighth day at 10 mg/L level of fluorine ion, from the fourth day at 25 mg/L level. Statistic test showed there were significant differences between the both groups (the experiment group and the control group). CONCLUSION: Fluoride may inhibit the expression of Smad4 in inner enamel epithelium of human tooth germ cultured in vitro .That suggests fluoride maybe disturb the signals′ transducing between the epithelia and mesenchyma in this way, then inhibit the differentiation and function of the tooth-forming cells.