Renard et al_SI.xlsx from DNA methylation extends lifespan in the bumblebee <i>Bombus terrestris</i>

Epigenetic alterations are a primary hallmark of ageing. In mammals, age-related epigenetic changes alter gene expression profiles, disrupt cellular homeostasis and physiological functions and, therefore, promote ageing. It remains unclear whether ageing is also driven by epigenetic mechanisms in invertebrates. Here, we used a pharmacological hypomethylating agent (RG108) to evaluate the effects of DNA methylation (DNAme) on lifespan in an insect—the bumble bee Bombus terrestris. RG108 extended mean lifespan by 43% and induced the differential methylation of genes involved in hallmarks of ageing, including DNA damage repair and chromatin organization. Furthermore, the longevity gene sirt1 was overexpressed following the treatment. Functional experiments demonstrated that SIRT1 protein activity was positively associated with lifespan. Overall, our study indicates that epigenetic mechanisms are conserved regulators of lifespan in both vertebrates and invertebrates and provides new insights into how DNAme is involved in the ageing process in insects.表观遗传改变（Epigenetic alterations）是衰老的核心标志性特征之一。在哺乳动物中，年龄相关的表观遗传改变会重塑基因表达谱、破坏细胞稳态与生理功能，进而促进衰老进程。目前尚不清楚无脊椎动物的衰老是否同样由表观遗传机制驱动。本研究采用药理学低甲基化试剂（RG108），以昆虫——熊蜂（Bombus terrestris）为实验对象，评估DNA甲基化（DNA methylation, DNAme）对其寿命的影响。RG108可将平均寿命延长43%，并诱导与衰老标志性特征相关的基因（包括DNA损伤修复、染色质组织相关基因）发生差异甲基化。此外，经RG108处理后，长寿基因沉默信息调节因子1（sirt1）呈现过表达状态。功能实验证实，SIRT1蛋白的活性与寿命呈正相关关系。综上，本研究表明表观遗传机制是脊椎动物与无脊椎动物共有的保守寿命调控因子，并为解析DNA甲基化参与昆虫衰老进程的机制提供了全新视角。