METHODS: Cultured LS8 were incubated with serum-free medium containing selected concentrations of NaF (0 ∼ 2 mM) for either 24 or 48 h. Subcellular microanatomy was characterized using TEM; meanwhile, selected biomolecules were analysed using various biochemistry techniques. Transient transfection was used to modulate a molecular pathway for apoptosis.
RESULTS: Apoptosis of LS8 was induced by NaF treatment that showed both time and concentration dependency. The activity of caspase-3, -8, -9 was found to be increased with NaF in a dose-dependent manner. Western blot revealed that the protein expression of p-ERK and p-JNK were decreased, while the expression of p-P38 was increased. Inhibition of the p-ERK and p-JNK pathways resulted in a similar decrease for caspase-3.
CONCLUSIONS: During NaF-induced apoptosis of LS8, p-ERK and p-JNK were closely associated with induction of apoptosis, which might be a mechanism of dental fluorosis.
方法:将培养的LS8与含有选定浓度的NaF(0〜2mM)的无血清培养基孵育24或48小时。使用TEM表征亚细胞显微解剖结构;同时,使用各种生物化学技术分析选定的生物分子。瞬时转染用于调节细胞凋亡的分子途径。
结果:NaF处理诱导了LS8的凋亡,表现出时间和浓度依赖性。发现半胱天冬酶-3、-8、-9的活性随NaF以剂量依赖性方式增加。Westernblot显示p-ERK和p-JNK蛋白表达降低,而p-P38的表达增加。p-ERK和p-JNK途径的抑制导致caspase-3的类似降低。
结论:在NaF诱导的LS8凋亡过程中,p-ERK和p-JNK与诱导凋亡密切相关。这可能是氟斑牙的一种机制。