Hao Hui, Yuan Siliang, Cheng Shiyang, Sun Qian, Giesy John P, Liu Chunsheng
Hubei Provincial Engineering Laboratory for Pond Aquaculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
Hubei Provincial Engineering Laboratory for Pond Aquaculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
Aquat Toxicol. 2020 May;222:105477. doi: 10.1016/j.aquatox.2020.105477. Epub 2020 Mar 26.
As a typical organophosphorus flame retardant, tris (2-chloroethyl) phosphate (TCEP) has been widely detected in various environmental media. Toxicity of TCEP to vertebrates have been investigated, but potential effects on lower trophic level species were unknown to date. In this study, toxic effects and molecular mechanisms of toxic actions of TCEP on the aquatic protozoan Tetrahymena thermophila were evaluated by use of phenotypic observations, transcriptome sequencing analysis and real-time quantitative PCR detection. Exposure to 0.044, 0.411 or 4.26 mg/L TCEP for 5 days decreased the theoretical population, cell viability, number of cilia and cell size of Tetrahymena thermophila in a time- and dose-dependent manner. Meanwhile, RNA-Seq analysis indicated that exposure to 4.26 mg/L TCEP significantly changed expression of 2932 genes (up-regulation: 1228; down-regulation: 1704). Of these, expressions of 9, 10 and 17 genes that were enriched in soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) interaction in vesicular transport, proteasome and endocytosis pathway respectively were down-regulated. Data collected during this study suggested that exposure to high concentrations of TCEP might affect growth and reproduction of Tetrahymena thermophila through down-regulating transcriptional levels of genes encoding proteins associated with vesicle trafficking, proteasome and endocytosis.
作为一种典型的有机磷阻燃剂，磷酸三（2-氯乙基）酯（TCEP）已在各种环境介质中被广泛检测到。TCEP对脊椎动物的毒性已得到研究，但迄今为止，其对低营养级物种的潜在影响尚不清楚。在本研究中，通过表型观察、转录组测序分析和实时定量PCR检测，评估了TCEP对水生原生动物嗜热四膜虫的毒性作用及毒性作用的分子机制。暴露于0.044、0.411或4.26mg/L的TCEP中5天，嗜热四膜虫的理论种群数量、细胞活力、纤毛数量和细胞大小以时间和剂量依赖的方式下降。同时，RNA测序分析表明，暴露于4.26mg/L的TCEP显著改变了2932个基因的表达（上调：1228个；下调：1704个）。其中，分别在囊泡运输中的可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）相互作用、蛋白酶体和内吞途径中富集的9个、10个和17个基因的表达下调。本研究收集的数据表明，暴露于高浓度的TCEP可能通过下调与囊泡运输、蛋白酶体和内吞作用相关的蛋白质编码基因的转录水平，影响嗜热四膜虫的生长和繁殖。
