Bioengineering Laboratory-CIETI, ISEP-School of Engineering of Polytechnic Institute of Porto, Rua Dr António Bernardino de Almeida, 431, 4200-072, Porto, Portugal.
CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
Appl Microbiol Biotechnol. 2018 Mar;102(6):2827-2838. doi: 10.1007/s00253-018-8802-2. Epub 2018 Feb 8.
The increasing use of nanoparticles (NPs) has spurred concerns about their toxic effects. This work aimed to assess the potential hazards of nickel oxide (NiO) NPs using the yeast Saccharomyces cerevisiae as a cell model. Yeast cells exposed for 6 h to 100 mg/L NiO NPs presented reduced metabolic activity (esterase activity and FUN-1 dye processing) and enhanced accumulation of reactive oxygen species. NiO NPs induced the loss of cell viability in a dose-dependent manner. Study of the dissolution of NiO NPs in aqueous media, together with the toxicological data, suggests that the nickel released by the NPs cannot explain all the toxic effects observed in S. cerevisiae caused by the NPs. Transmission electron microscopy observations revealed that NiO NPs were adsorbed onto cell surface but did not enter into yeast cells. Isogenic mutants (cwp1∆ and cwp2∆) with increased cell wall porosity did not display enhanced susceptibility to NiO NPs compared to the wild type strain. Our results suggest that NiO NPs exert their toxic effect by an indirect mechanism. This work contributes to knowledge of the potential hazards of NiO NPs and to the elucidation of their mechanisms of toxic action.
纳米粒子（NPs）的使用日益增多，引发了人们对其毒性影响的关注。本研究旨在以酵母酿酒酵母为细胞模型，评估氧化镍（NiO）NPs 的潜在危害。暴露于 100mg/L NiO NPs 下 6 小时的酵母细胞表现出代谢活性降低（酯酶活性和 FUN-1 染料处理）和活性氧物质积累增加。NiO NPs 以剂量依赖的方式诱导细胞活力丧失。对 NiO NPs 在水介质中溶解的研究以及毒理学数据表明，由 NPs 释放的镍不能解释由 NPs 引起的酿酒酵母中观察到的所有毒性作用。透射电子显微镜观察表明，NiO NPs 被吸附在细胞表面上，但没有进入酵母细胞。与野生型菌株相比，细胞壁孔隙率增加的同基因突变体（cwp1∆ 和 cwp2∆）对 NiO NPs 没有表现出更高的敏感性。我们的结果表明，NiO NPs 通过间接机制发挥其毒性作用。这项工作有助于了解 NiO NPs 的潜在危害，并阐明其毒性作用机制。
