不同质量浓度氟对大鼠切牙成釉细胞转化生长因子-β1表达的影响

The effect of different fluoride concentrations on the expression of transforming growth factor-β1 in amelo-blast of rat incisor

目的研究不同质量浓度氟对大鼠切牙生长过程中转化生长因子-β1(TGF-β1)表达的影响,探讨氟斑牙的发病机制。方法 40只Wistar大鼠随机分为3组,建立氟斑牙动物模型。3组分别为低剂量氟组(F-质量浓度60 mg.L-1,13只)、高剂量氟组(F-质量浓度120 mg.L-1,13只)和对照组(蒸馏水,14只)。10周后取材,采用苏木精-伊红(HE)染色和免疫组织化学染色的方法观察氟对大鼠切牙成釉细胞的形态及TGF-β1表达的影响。结果实验组大鼠切牙均出现典型的氟斑牙症状,牙面出现白垩色改变,釉质表面有横纹。HE染色结果显示成釉细胞形态发生改变,细胞排列紊乱,甚至成灶性堆积,可见空泡性变。免疫组织化学染色结果显示TGF-β1在分泌期和成熟期成釉细胞均为强阳性表达,在星网状层、中间层均为阳性表达,在新形成的釉基质中呈阳性表达。2个实验组TGF-β1的表达强度明显低于对照组(P<0.01),2个实验组之间的差异无统计学意义(P>0.05)。结论氟可能通过抑制TGF-β1的表达而干扰了成釉细胞的分化和基质分泌,造成釉质发育障碍。

Objective To investigate the effect of different concentrations of fluoride on the expression of trans-forming growth factor-β1（TGF-β1）,and explore the mechanism of dental fluorosis.Methods 40 Wistar rats were randomly divided into three groups,and supplied with low dose F-（60 mg·L-1,13 rats）,high dose F-（120 mg·L-1,13 rats） and distilled water（control group,14 rats） respectively.After 10 weeks,hematoxylin-eosin（HE） and immunohisto-chemistry staining were used to observe the changes of the ameloblasts and the expression of TGF-β1 in rat incisors.Results The fluoride groups showed typical symptoms of dental fluorosis.The surfaces of the rat teeth fed with fluoride appeared chalky color and cross striation on the enamel surface.The HE staining showed that the morphous of ameloblast were disarranged and cellular derangement,even appeared vacuolar change.TGF-β1 were expressed both in ameloblast of the secretory and maturation stage,and also in stellate reticulum and stratum intermedium.The ex-pression of TGF-β1 in rat＇s ameloblasts in experiment group was significantly lower than that in the control group（P0.01）,yet low dose group and high dose group still had no significant difference（P0.05）.Conclusion By inhibiting the expression of TGF-β1 in ameloblast,fluoride interferes the normal signal transduction between epithelial and mesenchymal,and affect the differentiation and development of enamel,so leading to the occurrence of dental fluorosis.