Objectives

Toothpaste with fluoride concentration up to 5000 ppm are recommended to the patients who are susceptible to root caries; however, the effects of fluoride on cementoblasts have received less attention.

Methods

The OCCM-30 cells were exposed to 0,0.5, 5, 10 mM NaF respectively. A TUNEL (TdT-mediated dUTP-biotin nick end labeling) assay kit was used to detect the DNA fragmentation. Hoechst staining was used to determine changes of nuclear morphology. Real-time quantitative RT-PCR and Western blotting were performed to investigate the mRNA and protein expression of caspase-3,-8,-9, cleaved Poly (ADP-ribose) polymerase (PARP) and Fas-ligand (Fas-L), a ligand of death receptor. CA-DCF-DA [5 (6)-Carboxy-2′,7′-dichlorofluorescein diacetate] was used to measure the generation of reactive oxygen species (ROS) in OCCM-30 cells after the NaF stimulation.

Results

The results showed apoptotic morphological changes and DNA fragmentation in OCCM-30 cells exposed to high concentration of NaF. 10 mM NaF induced the expression of cleaved caspase-3,-8,-9 and cleaved Poly (ADP-ribose) polymerase (PARP). The mRNA expression of the Fas-L was also increased in cells exposed to 5 mM NaF. Furthermore, 10 mM NaF stimulation resulted in a significant generation of ROS in the OCCM-30 cells.

Conclusions

Our research demonstrated that apoptosis is activated by NaF in OCCM-30 cells through both of the extrinsic death receptor-dependent and oxidative stress-related intrinsic apoptotic pathway.

Clinical significance

More consideration should be given about the fluoride concentration and the frequency of dental products when used to prevent the root caries for patients with gingival recession.

中文翻译：

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氟化钠在成骨细胞中引起氧化应激和细胞凋亡

目标

对于易患龋齿的患者，建议使用氟化物浓度最高为5000 ppm的牙膏。然而，氟化物对成骨细胞的作用受到的关注较少。

方法

将OCCM-30细胞分别暴露于0,0.5、5、10 mM NaF中。TUNEL（TdT介导的dUTP-生物素缺口末端标记）测定试剂盒用于检测DNA片段化。Hoechst染色用于确定核形态的变化。进行实时定量RT-PCR和Western印迹研究caspase-3，-8，-9，裂解的聚（ADP-核糖）聚合酶（PARP）和Fas-配体（Fas-L）的mRNA和蛋白表达。 ，是死亡受体的配体。CA-DCF-DA [5（6）-羧基-2'，7'-二氯荧光素二乙酸酯]用于测量NaF刺激后OCCM-30细胞中活性氧（ROS）的产生。

结果

结果显示，暴露于高浓度NaF的OCCM-30细胞凋亡形态变化和DNA片段化。10 mM NaF诱导裂解的caspase-3，-8，-9和裂解的聚（ADP-核糖）聚合酶（PARP）的表达。在暴露于5 mM NaF的细胞中，Fas-L的mRNA表达也有所增加。此外，10 mM NaF刺激导致OCCM-30细胞中大量生成ROS。

结论

我们的研究表明，NaF在OCCM-30细胞中通过外部死亡受体依赖性和氧化应激相关的固有凋亡途径激活细胞凋亡。

临床意义

当用于预防牙龈萎缩患者的龋齿时，应该更多地考虑氟化物的浓度和牙科产品的使用频率。