四膜虫摄取与外排AuNPs和Au(Ⅲ)的差异及单细胞异质性分析  

Uptake and efflux of AuNPs and ionic Au(Ⅲ)by Tetrahymena thermophila and the single-cell heterogeneity

作　　者：张柳 吴琪 曲广波 史建波[1,2,3] 江桂斌 ZHANG Liu;WU Qi;QU Guangbo;SHI Jianbo;JIANG Guibin(Institute of Environment and Health,Jianghan University,Wuhan,430056,China;State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing,100085,China;Advanced Research Institute of Hangzhou,University of Chinese Academy of Sciences,Hangzhou,310024,China)

机构地区：[1]江汉大学,环境与健康研究学院,武汉430056 [2]中国科学院生态环境研究中心,环境化学与生态毒理学国家重点实验室,北京100085 [3]中国科学院大学,杭州高等研究院,杭州310024

出　　处：《环境化学》2023年第7期2163-2170,共8页Environmental Chemistry

基　　金：国家自然科学基金(21976189)资助.

摘　　要：纳米材料的广泛应用导致其不可避免地对水环境造成污染.单细胞水生生物体内累积的纳米材料可能会沿着食物链/网向上传递,造成一定的环境风险.为了探究真实环境中的金属纳米颗粒及其溶解态金属离子对水生生物的影响,本文研究了在低剂量暴露下,单细胞水生生物嗜热四膜虫(四膜虫)对金纳米颗粒(AuNPs)和三价金离子(Au(Ⅲ))的累积特征.结果表明,1 ng·mL^(−1)暴露剂量下AuNPs和Au(Ⅲ)对四膜虫的膜通透性未产生明显影响;在持续暴露实验中,发现四膜虫累积Au(Ⅲ)与AuNPs相比有一定的滞后性;撤除暴露(48 h)后,四膜虫细胞内的AuNPs和Au(Ⅲ)会快速外排,但仍有部分AuNPs和Au(Ⅲ)未被排出.在整个实验过程中,四膜虫累积AuNPs和Au(Ⅲ)在单细胞水平具有较高的异质性,有一小部分个体(分别为6.72%和11.83%)能够累积较多的AuNPs和Au(Ⅲ),而这小部分个体有可能进入食物链/网对高营养级生物产生影响.借助质谱流式技术能够在单细胞水平同时检测多个金属元素的优势,可以通过适当的金属同位素生物分子标记物,进一步探究部分四膜虫细胞个体Au的异质性累积的分子机制.The wide application of nanomaterials inevitably results in the environmental water contamination.Nanoparticles accumulated in unicellular aquatic organisms could be transported to higher trophic levels through the food chain/web,causing certain environmental risks.To explore the effects of metal nanoparticles and metal ions on aquatic organisms in real environments,we investigated the characteristics of gold nanoparticles(AuNPs)and ionic Au(Ⅲ)accumulation by the unicellular aquatic organism Tetrahymena thermophila under low-dose exposure.The results showed that AuNPs and ionic Au(Ⅲ)had no significant effect on the membrane permeability of T.thermophila at 1 ng·mL^(−1).In the exposure experiment,we found that the accumulation of ionic Au(Ⅲ)by T.thermophila was slower than that of AuNPs.After the exposure was removed(48 h),AuNPs and ionic Au(Ⅲ)in T.thermophila were rapidly excreted,however,some AuNPs and ionic Au(Ⅲ)could not be eliminated.In this study,the heterogeneity of the accumulation of AuNPs and ionic Au(Ⅲ)in T.thermophila was revealed at the single-cell level.A few T.thermophila individuals(6.72%and 11.83%,respectively)could accumulate more AuNPs and ionic Au(Ⅲ)than other T.thermophila cells,and through these individuals,Au may affect the organisms at the higher trophic level.Since CyTOF allows multielement detection of a single cell,the mechanisms underlying different abilities of uptake of Au by T.thermophila cells could be further studied by utilizing proper stable metal isotope bio-markers.

关 键 词：单细胞分析 生物累积 金属纳米材料 单细胞质谱流式 细胞异质性. 

分 类 号：X171.5[环境科学与工程—环境科学]