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 mouse embryonic stem cells

Objective：We determined whether the methylation level of Nespas DMR was affected by the folate deficiency in the mouse ESCs and the relations between the methylation levels and the folate concentrations.Methods：Mouse ESCs were treated with various concentrations of folate and intracellular folate content was measured by chemiluminescent immunoassay.Methylation levels of the promoter region,exon region and intron region in Nespas DMR were examined by MassARRAY platform.The relationships between the methylation levels and the folate concentrations were analyzed by Pearson＇s correlation.Results：The intracellular folate concentration decreased 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 the promoter region and the intron region within Nespas DMR were positively correlated with folate content（P〈0.05）.Conclusion：Our data indicated that folate deficiency led to reduced Nespas DMR methylation in mouse ESCs.