短期高浓度氟对小鼠磨牙成釉细胞内BMP-2表达的影响

Effect of short exposure to high levels of fluoride induces the expression of BMP-2 in ameloblasts of mice molars

目的通过研究短期高浓度氟对小鼠磨牙成釉细胞形态及骨形成蛋白-2表达的影响,探讨氟对牙釉质发育的作用机制。方法选择4日龄的ICR小鼠共32只,随机分为两组,两组中均等分配实验动物和对照动物,将20mg/k(g体重)和10mg/kg(体重)的NaF分别单次注入实验动物腹腔内,将等剂量的NaCl分别单次注入对照动物腹腔内,注射量均为10μL/g,所有动物24h后被处死。HE染色、免疫组化染色被采用以观察两种浓度氟对小鼠磨牙不同分化阶段成釉细胞形态及骨形成蛋白-2的表达。结果实验组分泌期和过渡期的成釉细胞形态紊乱,对照组动物中BMP-2的表达明显高于实验组动物,差异有统计学意义(P<0.01),而成熟期成釉细胞未见明显变化。结论短期高浓度氟使骨形成蛋白-2在分泌期和过渡期成釉细胞中的表达被抑制,使釉质形成受阻。

Objective To study the BMP-2 expression and structure of ameloblasts of mice molars on the high levels of fluoride after short exposure. Then we explore the possible formation mechanisms of tooth enamel. Methods We selected 32 4-day-old ICR mice into two groups randomly. The experimental animals and the control animals in each group were equal. We gave a single intraperitoneal dose of 20（n=8） and 10（n=8） mg NaF/kg b.w.（body weight） to the experimental animals respectively,the controls （n=9 for each group）were received equal doses of NaC1. We kept the injected volume constant （10 μL/ g b.w.）. After 24 hours all mice were sacrificed. HE and immunohistochemical stainings were used to observe the structural changes and the expression of BMP-2 in ameloblasts of mouse molar at different stages. Results The secretory/transitional ameloblasts distored and lost its normal column contour. The immunohistochemistry results demonstrated that in control animals,the expression of BMP-2 was higher than those in experimental animals. There were significant differences between the statistics （P 〈 0.01）. We found no remarkable differences in maturation ameloblasts. Conclusion In the secretory and transitional ameloblasts,the expression of BMP-2 could be inhibited in the short exposure to high levels of fluoride. They lead to the abnormal development of enamel.