Molecular toxicity of cerium oxide nanoparticles to the freshwater alga Chlamydomonas reinhardtii is associated with supra-environmental exposure concentrations.
Molecular toxicity of cerium oxide nanoparticles to the freshwater alga Chlamydomonas reinhardtii is associated with supra-environmental exposure concentrations.
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DOI：
10.3109/17435390.2014.1002868
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发表时间：
2016
期刊：
影响因子：
5
通讯作者：
Viant MR
中科院分区：
文献类型：
--
作者：
Taylor NS;Merrifield R;Williams TD;Chipman JK;Lead JR;Viant MR
二氧化铈纳米颗粒（NPs）被广泛用作燃料催化剂，因此可能进入环境。在与环境有关的浓度下，它们对生物群的潜在影响，包括吸收和毒性，仍有待阐明，用于评估风险的定量数据也很少。因此，使用充分表征的单分散NP对二氧化铈NP的分子和表型效应进行了明确的评估，因为它们的毒性可能更高，从而能够进行保守的危害评估。使用无偏转录组学和代谢组学方法来研究严格限制的4-5 nm二氧化铈纳米颗粒对单细胞绿色藻类莱茵衣藻（Chlamyeliumreinhardtii）（一种哨兵淡水物种）的潜在毒性。从预测的环境水平（支持危害评估）到超环境水平（提供对分子毒性途径的深入了解），对广泛的接触浓度进行了研究。二氧化铈纳米颗粒被内化到C. reinhardtii，但在任何接触浓度下都不会对藻类生长产生显著影响。仅在超环境氧化铈NP浓度下检测到分子扰动，主要是光合作用和碳固定的下调，并对能量代谢产生相关影响。对于急性暴露于单分散小颗粒，可以得出结论，对于这种营养水平，应该很少关注它们向环境中的扩散。
Ceria nanoparticles (NPs) are widely used as fuel catalysts and consequently are likely to enter the environment. Their potential impacts on. biota at environmentally relevant concentrations, including uptake and toxicity, remain to be elucidated and quantitative data on which to assess risk are sparse. Therefore, a definitive assessment of the molecular and phenotypic effects of ceria NPs was undertaken, using well-characterised mono-dispersed NPs as their toxicity is likely to be higher, enabling a conservative hazard assessment. Unbiased transcriptomics and metabolomics approaches were used to investigate the potential toxicity of tightly constrained 4–5 nm ceria NPs to the unicellular green alga, Chlamydomonas reinhardtii, a sentinel freshwater species. A wide range of exposure concentrations were investigated from predicted environmental levels, to support hazard assessment, to supra-environmental levels to provide insight into molecular toxicity pathways. Ceria NPs were internalised into intracellular vesicles within C. reinhardtii, yet caused no significant effect on algal growth at any exposure concentration. Molecular perturbations were only detected at supra-environmental ceria NP-concentrations, primarily down-regulation of photosynthesis and carbon fixation with associated effects on energy metabolism. For acute exposures to small mono-dispersed particles, it can be concluded there should be little concern regarding their dispersal into the environment for this trophic level.