Endurance training remodels sperm-borne small RNA expression and methylation at neurological gene hotspots [RRBS]. Endurance training remodels sperm-borne small RNA expression and methylation at neurological gene hotspots [RRBS]

Remodelling of the sperm epigenome by lifestyle factors before conception could account for altered metabolism in the next generation offspring. Here, we hypothesized that endurance training changes the epigenome of human spermatozoa. Using small RNA (sRNA) sequencing and Reduced Representation Bisulfite Sequencing (RRBS), we respectively investigated sRNA expression and DNA methylation in pure fractions of motile spermatozoa collected from young healthy individuals before, after 6 weeks of endurance training and after 3 months without exercise. Expression of 8 piwi interacting RNA were changed by exercise training. RRBS analysis revealed 330 differentially methylated regions (DMRs) after training and 303 DMRs after the detraining period which were, in both conditions, enriched at close vicinity of transcription start sites. Ontology analysis of genes located at proximity of DMRs returned terms related to neurological function at the trained state and, to a much lesser extent, at the detrained state. Our study reveal that short-term endurance training induces marked remodelling of the sperm epigenome, and identify genes related to the development of the central nervous system as potential hot spots for epigenetic variation upon environmental stress. Overall design: Reduced representation bisulfite sequencing (RRBS) and sncRNA-Seq on the spermatozoa of 9 lean men undergoing endurance training

孕前生活方式因素对精子表观基因组的重塑，或可解释子代代谢异常的发生机制。本研究提出假设：耐力训练可改变人类精子的表观基因组。我们采用小RNA（small RNA, sRNA）测序与简化代表性亚硫酸氢盐测序（Reduced Representation Bisulfite Sequencing, RRBS）技术，分别对健康年轻个体在耐力训练6周前、训练后以及停训3个月后收集的高活力精子纯化组分中的sRNA表达水平与DNA甲基化状态进行了检测。研究发现，8种piwi相互作用RNA（piwi interacting RNA, piRNA）的表达在耐力训练后发生显著改变。RRBS分析结果显示，训练后共鉴定出330个差异甲基化区域（differentially methylated regions, DMRs），停训3个月后则鉴定出303个差异甲基化区域；两类条件下的差异甲基化区域均显著富集于转录起始位点附近区域。对差异甲基化区域邻近基因开展基因本体富集分析发现，训练状态下富集到与神经系统功能相关的术语，而停训状态下此类富集程度显著更低。本研究表明，短期耐力训练可显著重塑精子表观基因组，并明确中枢神经系统发育相关基因为环境应激诱导表观遗传变异的潜在热点区域。总体实验设计：对9名体瘦男性在耐力训练周期内采集的精子样本开展简化代表性亚硫酸氢盐测序（RRBS）与小非编码RNA测序（sncRNA-Seq）