叶酸缺乏对小鼠胚胎干细胞Nespas DMR 区甲基化修饰的影响

目的：探讨叶酸缺乏对小鼠胚胎干细胞（ESCs）中Nespas 差异甲基化区域（Differentially Methylated Region, DMR）甲基化修饰的影响以及叶酸浓度与甲基化水平的关系。方法：多种不同浓度叶酸处理小鼠ESCs，化学发光免疫分析法检测ESCs 细胞内叶酸浓度。利用MassARRAY 技术平台检测三种不同叶酸浓度处理后的ESCs中Nespas DMR 启动子区，外显子区和内含子区甲基化修饰状态，并且分析Nespas DMR 启动子区，外显子区和内含子区甲基化水平与叶酸浓度之间的关系。结果：无叶酸组（FF）小鼠ESCs 细胞内叶酸浓度显著低于低叶酸组（FD）与正常叶酸组（FN）（P<0.05）。Nespas DMR 中启动子区、外显子区以及内含子区甲基化水平在FF组显著低于FD 和FN 组（P<0.05），并且Nespas DMR中启动子区以及内含子区甲基化水平与叶酸浓度存在显著的正相关（P<0.05）。结论：叶酸缺乏影响小鼠ESCs 中Nespas DMR 区甲基化修饰的建立。

The Nespas DMR hypomethylation in folate-deficient mouseembryonic stemcells

Objective:We determined whether the methylation level of Nespas DMR was affected by the folate deficiency in themouse ESCs and the relations between the methylation levels and the folate concentrations.Methods:Mouse ESCs were treated withvarious concentrations of folate and intracellular folate content was measured by chemiluminescent immunoassay. Methylation levels ofthe promoter region, exon region and intron region in Nespas DMR were examined by MassARRAY platform. The relationships betweenthe methylation levels and the folate concentrations were analyzed by Pearson''s correlation.Results:The intracellular folate concentrationdecreased under folate-deficient condition(P<0.05). Folate insufficiency induced significantly lower methylation level in folate-free group(FF) compared with that in folate-deficient group (FD) and folate-normal group (FN) (P<0.05). Moreover, methylation levels of thepromoter region and the intron region within Nespas DMR were positively correlated with folate content (P<0.05).Conclusion:Our dataindicated that folate deficiency led to reduced Nespas DMR methylation in mouse ESCs.