Genome-Wide Bacterial Toxicity Screening Uncovers the Mechanisms of Toxicity of a Cationic Polystyrene Nanomaterial
Genome-Wide Bacterial Toxicity Screening Uncovers the Mechanisms of Toxicity of a Cationic Polystyrene Nanomaterial
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DOI：
10.1021/es203087m
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发表时间：
2012-02-21
影响因子：
11.4
通讯作者：
Godwin, Hilary
中科院分区：
文献类型：
--
作者：
Ivask, Angela;Suarez, Elizabeth;Godwin, Hilary
通过利用细菌单基因缺失突变体的全基因组集合，我们研究了60 nm阳离子（氨基官能化）聚苯乙烯纳米材料（PS-NH 2）在细菌细胞中的毒理学途径。市售60 nm PS-NH 2的IC 50测定为158 μ g/mL，IC 5为108 μ g/mL，母体E的IC 90为190 μ g/mL。coli菌株的基因缺失文库。超过4000个单一的非必需基因缺失突变体的大肠杆菌进行了筛选，每个菌株的生长表型在PS-NH 2的存在和不存在。这表明，脂多糖生物合成途径、外膜转运通道、泛醌生物合成途径、鞭毛运动和DNA修复系统中的基因簇对该生物体如何响应阳离子纳米材料都很重要。这些结果，连同来自本文所述的验证性测定的那些结果，表明60-nm PS-NH 2纳米材料在大肠杆菌中的毒性的主要机制。大肠杆菌是外膜的不稳定和活性氧的产生。本文报告的方法应证明可普遍用于确定细胞如何对各种纳米材料作出反应的途径，并确定不同类型纳米材料的细胞毒性机制。
By exploiting a genome-wide collection of bacterial single-gene deletion mutants, we have studied the toxicological pathways of a 60-nm cationic (amino-functionalized) polystyrene nanomaterial (PS-NH2) in bacterial cells. The IC50 of commercially available 60 nm PS-NH2 was determined to be 158 mu g/mL, the IC5 is 108 mu g/mL, and the IC90 is 190 mu g/mL for the parent E. coli strain of the gene deletion library. Over 4000 single nonessential gene deletion mutants of Escherichia coli were screened for the growth phenotype of each strain in the presence and absence of PS-NH2. This revealed that genes clusters in the lipopolysaccharide biosynthetic pathway, outer membrane transport channels, ubiquinone biosynthetic pathways, flagellar movement, and DNA repair systems are all important to how this organism responds to cationic nanomaterials. These results, coupled with those from confirmatory assays described herein, suggest that the primary mechanisms of toxicity of the 60-nm PS-NH2 nanomaterial in E. coli are destabilization of the outer membrane and production of reactive oxygen species. The methodology reported herein should prove generally useful for identifying pathways that are involved in how cells respond to a broad range of nanomaterials and for determining the mechanisms of cellular toxicity of different types of nanomaterials.