Wu Minghong, Liu Shuai, Hu Lei, Qu Haidong, Pan Chenyuan, Lei Penghui, Shen Yingjia, Yang Ming
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 China.
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 China; College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361005, China.
Aquat Toxicol. 2017 Nov;192:274-283. doi: 10.1016/j.aquatox.2017.09.027. Epub 2017 Sep 28.
Antidepressants are among the most commonly detected pharmaceuticals in aqueous systems, and, as emerging organic pollutants, may exert negative effects on non-target aquatic organisms. Previously, it has been revealed that antidepressant exposure significantly inhibits the growth and development of fish during their early developmental stages. Thus, in the present study, we aimed to identify and compare the underlying mechanisms of action of different antidepressants at the transcriptional level using zebrafish (Danio rerio) embryos. Through high-throughput RNA sequencing (RNA-Seq) data analysis, 32, 34, and 130 differentially expressed genes (DEGs) were obtained from zebrafish larvae after 120h of embryonic exposure to sublethal concentrations of amitriptyline, fluoxetine, and mianserin, respectively. The expression profiles of the identified DEGs showed similar trends in response to the three antidepressant treatments, suggesting consistent toxic effects of low concentrations of these three drugs on the regulation of gene expression in fish. Several metabolic and signaling pathways, including glycolysis/gluconeogenesis and the insulin pathway, were affected in the exposed fish larvae. The expression profiles of selected DEGs were then verified by the qRT-PCR method, which indicated significant positive correlations with the RNA-Seq results. Next, we determined the concentration-dependent expression patterns of 6 selected DEGs in fish larvae exposed to three antidepressants at a series of environmentally relevant concentrations. The results revealed a significant concentration-dependent reduction in the levels of dual-specificity phosphatase 5 (dusp5) mRNA, as well as a non-concentration-dependent gene expression inhibition of prostaglandin D2 synthase b (ptgdsb); the circadian rhythm-related genes, i.e. those encoding nuclear receptor subfamily 1, group D, member 1 (nr1d1) and period 2 (per2); and genes encoding early growth response factors (egr1 and egr4), in the antidepressant-treated fish larvae. In summary, to our knowledge, our findings demonstrate, for the first time, that the three different categories of antidepressants have common effects on the gene expression involved in multiple biological processes and signaling pathways during the early development of fish and thus provide information for characterizing the adverse outcome pathways and on the ecological risk assessment of these pharmaceutical pollutants in the aquatic environment.
抗抑郁药是水系统中最常检测到的药物之一，作为新兴有机污染物，可能对非目标水生生物产生负面影响。此前研究表明，抗抑郁药暴露会显著抑制鱼类早期发育阶段的生长和发育。因此，在本研究中，我们旨在利用斑马鱼（Danio rerio）胚胎在转录水平上鉴定和比较不同抗抑郁药的潜在作用机制。通过高通量RNA测序（RNA-Seq）数据分析，在胚胎暴露于亚致死浓度的阿米替林、氟西汀和米安色林120小时后，分别从斑马鱼幼虫中获得了32、34和130个差异表达基因（DEG）。所鉴定的DEG的表达谱在对三种抗抑郁药处理的反应中显示出相似趋势，表明低浓度的这三种药物对鱼类基因表达调控具有一致的毒性作用。暴露的鱼类幼虫中，包括糖酵解/糖异生和胰岛素途径在内的几种代谢和信号通路受到影响。然后通过qRT-PCR方法验证了所选DEG的表达谱，结果表明与RNA-Seq结果具有显著正相关。接下来，我们确定了在一系列与环境相关浓度下暴露于三种抗抑郁药的鱼类幼虫中6个所选DEG的浓度依赖性表达模式。结果显示，双特异性磷酸酶5（dusp5）mRNA水平显著呈浓度依赖性降低，以及前列腺素D2合酶b（ptgdsb）、昼夜节律相关基因（即编码核受体亚家族1、D组成员1（nr1d1）和周期蛋白2（per2）的基因）和编码早期生长反应因子（egr1和egr4）的基因在抗抑郁药处理的鱼类幼虫中呈非浓度依赖性基因表达抑制。总之，据我们所知，我们的研究结果首次证明，这三种不同类别的抗抑郁药在鱼类早期发育过程中对参与多个生物过程和信号通路的基因表达具有共同影响，从而为表征不良结局途径以及对这些药物污染物在水生环境中的生态风险评估提供了信息。
