氟暴露儿童ERα基因甲基化水平与氟斑牙及血清钙水平的关系
Relationship between dental fluorosis, serum calcium level, and ERα gene methylation in children exposed to fluoride

目的:分析雌激素受体α(ERα)基因启动子区甲基化水平与儿童氟斑牙及血清钙水平的关系。方法:采用整群抽样的方法抽取河南省某县氟病区2所小学8～12岁儿童174人,采用Dean分级法对儿童氟斑牙进行分级,并依据病情分为正常组(n=85)、轻度组(n=53)和中重度组(n=36)。采用原子吸收分光光度法测定血清钙含量,采用氟离子选择电极法测定尿氟含量,采用real-time PCR法检测ERα基因启动子区甲基化率。结果:中重度组男性儿童ERα基因启动子区甲基化率为(2.61±0.95)%,高于正常组儿童的(1.89±0.74)%和轻度组儿童的(1.99±0.89)%(P均<0.05); 3组女性儿童ERα基因启动子区甲基化率比较,差异无统计学意义(F=0.585,P=0.559)。ERα基因启动子区甲基化率与血清钙水平呈负相关(r=-0.172,P=0.024)。结论:ERα基因启动子区甲基化水平可能与儿童氟斑牙患病程度有关,且存在性别差异; ERα基因启动子区甲基化水平与血清钙水平呈负相关。
dental fluorosis; estrogen receptor α; DNA methylation; serum calcium Abstract Aim: To explore the relationship between estrogen receptor α(ERα)gene methylation and children dental fluorosis,serum calcium level.Methods: A total of 174 primary school students aged 8～12 years, born and raised up in fluoride exposure areas of Henan Province were selected by cluster sampling, and were divided into normal group(n=85), mild group(n=53), as well as moderate and severe group(n=36)according to dental fluorosis degree. Dental fluorosis was identified with Dean method. Urine fluoride and serum calcium levels were determined using fluoride ion selective electrode and flame atomic absorption spectrometry methods, respectively. The methylation level of ERα gene promoter was detected by real-time PCR procedure.Results: The percentage of ERα gene methylation in the boys of moderate and severe group[(2.61±0.95)%] was significantly higher than those in normal group[(1.89±0.74)%] and mild group [(1.99±0.89)%](P<0.05). No significant difference in ERα gene methylation percentage was observed among the girls from different groups(F=0.585,P=0.559). Negative correlation between methylation level in ERα gene and serum calcium level of children was observed(r=-0.172,P=0.024).Conclusion: ERα gene methylation may be related with the degree of children dental fluorosis and this may have gender specificity. There is a negative correlation between the methylation level of ERα gene and serum calcium level