Genome-wide sequencing of hippocampal 5-hydroxymethylcytosine links plasticity genes to acute stress

We used an established chemical labeling and affinity purification method coupled with high-throughput sequencing technology to generate the first genome-wide profile of hippocampal 5hmC following exposure to acute restraint stress and a one-hour recovery. This approach found a genome-wide disruption in 5hmC associated with acute stress response, primarily in genic regions, and identified known and potentially novel stress-related targets that have a significant enrichment for neuronal ontological functions. Integration of these data with hippocampal gene expression data from these same mice found stress-related hydroxymethylation correlated to altered transcript levels and sequence motif predictions indicated that 5hmC may function by mediating transcription factor binding to these transcripts. Together, these data reveal an environmental impact on this newly discovered epigenetic mark in the brain and represent a critical step toward understanding stress-related epigenetic mechanisms that alter gene expression and can lead to the development of psychiatric disorders. Overall design: Examined the effect of a 30 minutes acute stress on hippocampal 5hmC profile of adult C57BL/6J background male mice.

本研究采用成熟的化学标记与亲和纯化方法联合高通量测序技术，首次获得了急性束缚应激暴露并恢复1小时后小鼠海马体5-羟甲基胞嘧啶（5hmC）的全基因组图谱。该研究发现，与急性应激应答相关的5hmC修饰存在全基因组范围的紊乱，此类紊乱主要发生于基因区域；同时鉴定出已知及潜在的新型应激相关靶点，这些靶点显著富集神经元功能相关的基因本体注释。将本研究数据与同批次小鼠的海马体基因表达数据进行整合分析后发现，应激相关的羟甲基化修饰与转录水平变化显著相关；序列基序预测分析表明，5hmC可能通过介导转录因子与对应转录本的结合发挥功能。综上，本研究数据揭示了环境应激对大脑中新发现的表观遗传标记的影响，为理解应激相关表观遗传机制迈出了关键一步——此类机制可改变基因表达，进而诱发精神疾病的发生发展。实验设计概述：探究30分钟急性应激对成年C57BL/6J背景雄性小鼠海马体5hmC图谱的影响。