Département de Chimie, Université de Montréal, Succursale Centre-Ville, Montréal, Quebec, Canada.
Appl Environ Microbiol. 2013 Aug;79(16):4774-85. doi: 10.1128/AEM.00998-13. Epub 2013 May 31.
The widespread use of nanoparticles (NPs) raises concern over their potential toxicological effects in humans and ecosystems. Here we used transcriptome sequencing (RNA-seq) to evaluate the effects of exposure to four different metal-based NPs, nano-Ag (nAg), nano-TiO2 (nTiO2), nano-ZnO (nZnO), and CdTe/CdS quantum dots (QDs), in the eukaryotic green alga Chlamydomonas reinhardtii. The transcriptome was characterized before and after exposure to each NP type. Specific toxicological effects were inferred from the functions of genes whose transcripts either increased or decreased. Data analysis resulted in important differences and also similarities among the NPs. Elevated levels of transcripts of several marker genes for stress were observed, suggesting that only nZnO caused nonspecific global stress to the cells under environmentally relevant conditions. Genes with photosynthesis-related functions were decreased drastically during exposure to nTiO2 and slightly during exposures to the other NP types. This pattern suggests either toxicological effects in the chloroplast or effects that mimic a transition from low to high light. nAg exposure dramatically elevated the levels of transcripts encoding known or predicted components of the cell wall and the flagella, suggesting that it damages structures exposed to the external milieu. Exposures to nTiO2, nZnO, and QDs elevated the levels of transcripts encoding subunits of the proteasome, suggesting proteasome inhibition, a phenomenon believed to underlie the development and progression of several major diseases, including Alzheimer's disease, and used in chemotherapy against multiple myeloma.
纳米粒子（NPs）的广泛应用引起了人们对其在人类和生态系统中潜在毒理学效应的关注。在这里，我们使用转录组测序（RNA-seq）来评估暴露于四种不同金属基 NPs（纳米银（nAg）、纳米二氧化钛（nTiO2）、纳米氧化锌（nZnO）和碲化镉/硫化镉量子点（QDs））对真核绿藻莱茵衣藻的影响。在每种 NP 类型暴露前后，对转录组进行了特征描述。通过转录本增加或减少的基因的功能，推断出特定的毒理学效应。数据分析结果表明，四种 NPs 之间存在重要的差异和相似之处。观察到几种应激标记基因的转录本水平升高，表明只有 nZnO 在环境相关条件下对细胞造成非特异性的全局应激。暴露于 nTiO2 时，与光合作用相关的基因功能急剧下降，而暴露于其他 NP 类型时则略有下降。这种模式表明要么是叶绿体的毒理学效应，要么是类似于从低光到高光的转变。nAg 暴露显著提高了已知或预测的细胞壁和鞭毛成分的编码转录本水平，表明它破坏了暴露于外部环境的结构。暴露于 nTiO2、nZnO 和 QDs 会提高蛋白酶体亚基的转录本水平，表明蛋白酶体抑制，这一现象被认为是阿尔茨海默病等几种主要疾病的发展和进展的基础，并被用于多发性骨髓瘤的化疗。
