Cervera-Juanes R, Wilhelm L J, Park B, Grant K A, Ferguson B
Department of Neurosciences, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA.
Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, OR, USA.
Transl Psychiatry. 2017 Jan 10;7(1):e994. doi: 10.1038/tp.2016.266.
Alterations in DNA methylation have been associated with alcohol exposure and proposed to contribute to continued alcohol use; however, the molecular mechanisms involved remain obscure. We investigated the escalating effects of alcohol use on DNA methylation, gene expression and predicted neural effects in the nucleus accumbens of rhesus macaques that self-administered 4% alcohol for over 12 months. Using an exploratory approach to identify CpG-rich regions, followed by bisulfite sequencing, the methylation levels of 2.7 million CpGs were compared between seven low-binge drinkers and nine heavy-very heavy drinking subjects. We identified 17 significant differential methylation regions (DMRs), including 14 with methylation levels that were correlated with average daily alcohol consumption. The size of the DMRs ranged from 29 to 158 bp (mean=63.7), included 4-19 CpGs per DMR (mean=8.06) and spanned a range of average methylation values from 5 to 34%. Eight of the DMRs mapped to genes implicated in modulating synaptic plasticity. Six of the synaptic genes have not previously been linked to alcohol use. Validation studies of these eight DMRs using bisulfite amplicon sequencing and an expanded set of 30 subjects confirmed the significant alcohol-dose-associated methylation of the DMRs. Expression analysis of three of the DMR-associated genes, LRP5, GPR39 and JAKMIP1, revealed significant correlations between DMR methylation and whole-gene or alternative transcript expression, supporting a functional role in regulating gene expression. Together, these studies suggest that alcohol-associated synaptic remodeling may be regulated and coordinated at the level of DNA methylation.
DNA甲基化的改变与酒精暴露有关，并被认为与持续饮酒有关；然而，其中涉及的分子机制仍不清楚。我们研究了恒河猴伏隔核中酒精使用对DNA甲基化、基因表达以及预测的神经效应的逐步影响，这些恒河猴自行饮用4%的酒精超过12个月。我们采用探索性方法来识别富含CpG的区域，随后进行亚硫酸氢盐测序，比较了7名低度暴饮者和9名重度-极重度饮酒者之间270万个CpG的甲基化水平。我们鉴定出17个显著的差异甲基化区域（DMR），其中14个区域的甲基化水平与平均每日酒精摄入量相关。DMR的大小范围为29至158 bp（平均=63.7），每个DMR包含4至19个CpG（平均=8.06），平均甲基化值范围为5%至34%。其中8个DMR映射到与调节突触可塑性相关的基因。其中6个突触基因以前未与酒精使用相关联。使用亚硫酸氢盐扩增子测序和30名受试者的扩展样本对这8个DMR进行的验证研究证实了DMR与酒精剂量相关的显著甲基化。对3个与DMR相关的基因LRP5、GPR39和JAKMIP1的表达分析表明，DMR甲基化与全基因或可变转录本表达之间存在显著相关性，支持其在调节基因表达中的功能作用。总之，这些研究表明，酒精相关的突触重塑可能在DNA甲基化水平上受到调节和协调。
