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）以原始态与转化态在自然环境中的多代暴露场景愈发普遍，但其引发的多代暴露效应目前仍未明确。本研究以秀丽隐杆线虫（Caenorhabditis elegans）为受试生物，探究了10代持续暴露对其暴露于原始态银纳米颗粒、硫化银纳米颗粒（sulfidized Ag ENPs）以及硝酸银（AgNO3）时敏感性的影响。本研究同时设置了恢复种群：初始经6代暴露后，后续4代不进行暴露处理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、原始态银纳米颗粒、硫化银纳米颗粒（Ag2S ENPs）。持续暴露于原始态银纳米颗粒与硝酸银会使F2代线虫产生显著的敏感性增强效应（约为对照组的10倍），且该效应可延续至F10代。而硫化银纳米颗粒暴露引发的敏感性增强效应相对微弱，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。在恢复种群中，初始多代暴露所引发的对原始态银纳米颗粒与硝酸银的敏感性残留效应依然存在。其各项检测终点的响应敏感性与末次祖先暴露世代（F5）更为接近，而非未暴露对照组种群。敏感性的跨代传递机制可能通过表观基因组（epigenome）介导，我们呼吁学界优先开展此类机制毒理学相关研究。