DNA methylation is an epigenetic modification of genome that is involved in many human diseases. Recent studies revealed DNA methylation may be associated with fluorosis. This study was aimed to evaluate the dose-response effect of fluoride on DNA methylation in human and rat blood. A commercial ELISA kit was employed to evaluate 5-methylcytosine (5-mC) level of genome in human and rat blood. A total of 281 subjects were enrolled in this study and divided into four equal-size groups by the quartile of fluoride in drinking water. The difference of 5-mC among the four groups was significant. The U-shaped relationship was found between fluoride and 5-mC in the population. The U-shaped curve was also observed in the rats with three months of fluoride treatments. Taken together, these results clue the disruption of DNA methylation in mammals may has a certain association with fluoride in natural exposures.

DNA甲基化是基因组的表观遗传修饰，与许多人类疾病有关。最近的研究表明 DNA 甲基化可能与氟中毒有关。本研究旨在评估氟化物对人和大鼠血液中 DNA 甲基化的剂量反应效应。采用商业 ELISA 试剂盒评估人和大鼠血液中基因组的 5-甲基胞嘧啶 (5-mC) 水平。共有 281 名受试者参加了这项研究，并根据饮用水中氟化物的四分位数分为四个大小相等的组。四组间5-mC差异有显着性。人群中氟化物与 5-mC 之间存在 U 形关系。在接受三个月氟化物治疗的大鼠中也观察到了 U 形曲线。总而言之，这些结果表明哺乳动物 DNA 甲基化的破坏可能与自然接触氟化物有一定的关联。