Data from: Multigenerational exposure to silver ions and silver nanoparticles reveals heightened sensitivity and epigenetic memory in Caenorhabditis elegans

The effects from multigenerational exposures to engineered nanoparticles (ENPs) in their pristine and transformed states are currently unknown despite such exposures being an increasingly common scenario in natural environments. Here, we examine how exposure over 10 generations affects the sensitivity of the nematode Caenorhabditis elegans to pristine and sulfidized Ag ENPs and AgNO3. We also include populations that were initially exposed over six generations but kept unexposed for subsequent four generations to allow recovery from exposure. Toxicity of the different silver forms decreased in the order AgNO3, Ag ENPs and Ag2S ENPs. Continuous exposure to Ag ENPs and AgNO3 caused pronounced sensitization (approx. 10-fold) in the F2 generation, which was sustained until F10. This sensitization was less pronounced for Ag2S ENP exposures, indicating different toxicity mechanisms. Subtle changes in size and lifespan were also measured. In the recovery populations, the sensitivity to Ag ENPs and AgNO3 resulting from the initial multigenerational exposure persisted. Their response sensitivity for all endpoints was most closely related to the last ancestral exposed generation (F5), rather than unexposed controls. The mechanisms of transgenerational transfer of sensitivity are probably organized through the epigenome, and we encourage others to investigate such effects as a priority for mechanistic toxicology.

尽管工程纳米颗粒（engineered nanoparticles, ENPs）的原生态与转化态在自然环境中的多代暴露场景已日益普遍，但目前学界对这类暴露所产生的影响仍不明晰。本研究针对10代暴露过程中，秀丽隐杆线虫（Caenorhabditis elegans）对原生态、硫化改性银基工程纳米颗粒（sulfidized Ag ENPs）以及硝酸银（AgNO3）的敏感性变化展开探究。同时设置恢复组种群：先经6代暴露，后续4代停止暴露以实现暴露后的恢复。不同银基制剂的毒性强弱依次为：硝酸银 > 银基工程纳米颗粒（Ag ENPs） > 硫化银工程纳米颗粒（Ag2S ENPs）。持续暴露于Ag ENPs与硝酸银会使F2代线虫产生显著的敏感性增强效应（约为对照的10倍），且该效应可持续至F10代。而Ag2S ENPs暴露引发的敏感性增强效应则相对微弱，提示二者的毒性作用机制存在差异。研究同时观测到线虫体型与寿命的细微变化。在恢复组种群中，初始多代暴露所引发的对Ag ENPs与硝酸银的敏感性仍持续存在。该种群的各项检测终点的响应敏感性，与末次祖先暴露代（F5）的关联性显著高于未暴露对照组。敏感性的跨代传递机制可能通过表观基因组（epigenome）调控，我们呼吁学界将此类效应作为机制毒理学的优先研究方向。