藏、汉族EPAS1基因启动子区DNA甲基化的差异研究

Investigation of DNA Methylation Difference in EPAS1 Promoter Region between Tibetan and Han Population

目的对比世居高原藏族、世居平原汉族及久居高原汉族中EPAS 1基因启动子区DNA甲基化水平差异,分析EPAS 1基因DNA甲基化在高原低氧适应中的可能作用。方法世居高原藏族、世居平原汉族及久居高原汉族健康男性志愿者各10例,采集EDTA抗凝外周血,提取血液基因组DNA,采用Agena MassArray核酸质谱技术定量检测平原汉族、久居高原汉族及高原藏族3组人群中DNA甲基化程度的差异。提取上述分组血液样本总RNA,反转录为cDNA,qRT-PCR技术检测不同组EPAS 1基因表达量的差异。结果平原汉族、久居高原汉族及高原藏族人群中EPAS 1基因启动子区整体DNA甲基化程度分别为8.87%±10.31%、7.17%±10.12%、9.32%±13.07%,3组人群中均无统计学差异(P>0.05);EPAS 1基因启动子区部分CpG位点的甲基化程度在3组人群中存在显著差异(P<0.05);EPAS 1基因rs13419896、rs1868092及rs4953354位点序列突变与3组人群的DNA甲基化程度无统计学差异(P>0.05)。久居高原汉族EPAS 1基因mRNA表达量显著高于平原汉族,世居高原藏族略高于平原汉族。结论EPAS 1基因启动子区部分CpG位点的DNA甲基化水平在藏、汉族中存在差异,久居高原汉族可能通过DNA甲基化的改变来适应高原低氧环境。

Objective To investigate the role of DNA methylation of EPAS 1 gene in the adaptation to hypoxia at high altitude by comparing the difference of DNA methylation levels in the EPAS 1 gene promoter region among Tibetan group,plain Han group and plateau Han group(>10 years).Methods Blood samples were collected from 30 healthy male volunteers of Tibetan,plain Han and plateau Han,and genomic DNA was extracted.Agena Massarray nucleic acid mass spectrometry was used to quantitatively detect the difference in the degree of DNA methylation among these groups.Total RNA was extracted from the above groups,and the reverse transcription was cDNA.The mRNA expression levels of EPAS 1 in different groups were detected by qRT-PCR.Results The overall DNA methylation degree of EPAS 1 gene promoter region was 8.87%±10.31%,7.17%±10.12%,9.32%±13.07%in the plain Han,plateau Han and Tibetan,respectively,and there was no statistical difference among the three groups(P>0.05).The methylation levels of part of CpG sites in EPAS 1 gene promoter region were significantly different among the three groups(P<0.05).At the same time,the relationship between sequence mutations at rs13419896,rs1868092 and rs4953354 of EPAS 1 gene and DNA methylation was analyzed.There was no statistical difference among the groups(P>0.05).The expression level of EPAS1 mRNA was significantly higher in plateau Han than in plain Han,and slightly higher in Tibetan than in plain Han.Conclusion The DNA methylation level of some CpG sites in EPAS1 gene promoter region is different between Tibetan and Han population,and plateau Han may participate in the adaptation process of hypoxia through the change of DNA methylation.