School of Environment, Beijing Normal University, 19 Xinjiekouwai Street, 100875 Beijing, P. R. China.
School of Energy & Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, P. R. China.
Environ Sci Technol. 2021 Dec 7;55(23):15776-15787. doi: 10.1021/acs.est.1c04059. Epub 2021 Nov 17.
Increased release of engineered nanoparticles (ENPs) from widely used commercial products has threatened environmental health and safety, particularly the repeated exposures to ENPs with relatively low concentration. Herein, we studied the response of () to single and repeated exposures to silver nanoparticles (AgNPs). Repeated exposures to AgNPs promoted chlorophyll a and carotenoid production, and increased silver accumulation, thus enhancing the risk of AgNPs entering the food chain. Notably, the extracellular polymeric substances (EPS) content of the 1-AgNPs and 3-AgNPs groups were dramatically increased by 119.1% and 151.5%, respectively. We found that cells exposed to AgNPs had several significant alterations in metabolic process and cellular transcription. Most of the genes and metabolites are altered in a dose-dependent manner. Compared with the control group, single exposure had more differential genes and metabolites than repeated exposures. 562, 1341, 4014, 227, 483, and 2409 unigenes were differentially expressed by 1-0.5-AgNPs, 1-5-AgNPs, 1-10-AgNPs, 3-0.5-AgNPs, 3-5-AgNPs, and 3-10-AgNPs treatment groups compared with the control. Metabolomic analyses revealed that AgNPs altered the levels of sugars and amino acids, suggesting that AgNPs reprogrammed carbon/nitrogen metabolism. The changes of genes related to carbohydrate and amino acid metabolism, such as citrate synthase (CS), isocitrate dehydrogenase (IDH1), and malate dehydrogenase (MDH), further supported these results. These findings elucidated the mechanism of biological responses to repeated exposures to AgNPs, providing a new perspective on the risk assessment of nanomaterials.
广泛使用的商业产品中释放出的工程纳米颗粒（ENPs）增加了对环境健康和安全的威胁，尤其是相对低浓度的 ENPs 的重复暴露。在此，我们研究了 （）对银纳米颗粒（AgNPs）的单次和重复暴露的反应。重复暴露于 AgNPs 促进了叶绿素 a 和类胡萝卜素的产生，并增加了银的积累，从而增加了 AgNPs 进入食物链的风险。值得注意的是，1-AgNPs 和 3-AgNPs 组的细胞外聚合物（EPS）含量分别显著增加了 119.1%和 151.5%。我们发现 AgNPs 暴露的 细胞在代谢过程和细胞转录中有几个显著的改变。大多数基因和代谢物都呈剂量依赖性变化。与对照组相比，单次暴露比重复暴露有更多的差异基因和代谢物。与对照组相比，1-0.5-AgNPs、1-5-AgNPs、1-10-AgNPs、3-0.5-AgNPs、3-5-AgNPs 和 3-10-AgNPs 处理组的 562、1341、4014、227、483 和 2409 个基因差异表达。代谢组学分析表明，AgNPs 改变了糖和氨基酸的水平，表明 AgNPs 重新编程了碳/氮代谢。与碳水化合物和氨基酸代谢相关的基因的变化，如柠檬酸合酶（CS）、异柠檬酸脱氢酶 1（IDH1）和苹果酸脱氢酶（MDH），进一步支持了这些结果。这些发现阐明了生物对重复暴露于 AgNPs 的反应机制，为纳米材料的风险评估提供了新的视角。
