Environment and Geography, University of Manitoba, Winnipeg, MB, Canada.
Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada.
J Hazard Mater. 2024 Mar 5;465:133299. doi: 10.1016/j.jhazmat.2023.133299. Epub 2023 Dec 19.
Traditional risk assessment methods face challenges in the determination of drivers of toxicity for complex mixtures such as those present at legacy-contaminated sites. Bioassay-driven analysis across several levels of biological organization represents an approach to address these obstacles. This study aimed to apply a novel transcriptomics tool, the EcoToxChip, to characterize the effects of complex mixtures of contaminants in adult fathead minnows (FHMs) and to compare molecular response patterns to higher-level biological responses. Adult FHMs were exposed for 4 and 21 days to groundwater mixtures collected from a legacy-contaminated site. Adult FHM showed significant induction of micronuclei in erythrocytes, decrease in reproductive capacities, and some abnormal appearance of liver histology. Parallel EcoToxChip analyses showed a high proportion of upregulated genes and a few downregulated genes characteristic of compensatory responses. The three most enriched pathways included thyroid endocrine processes, transcription and translation cellular processes, and xenobiotics and reactive oxygen species metabolism. Several of the most differentially regulated genes involved in these biological pathways could be linked to the apical outcomes observed in FHMs. We concluded that molecular responses as determined by EcoToxChip analysis show promise for informing of apical outcomes and could support risk assessments of complex contaminated sites.
传统的风险评估方法在确定复杂混合物（如遗留污染场地中的混合物）的毒性驱动因素方面面临挑战。通过多个层次的生物组织进行生物测定驱动分析是解决这些障碍的一种方法。本研究旨在应用一种新型的转录组学工具——EcoToxChip 来描述污染物复杂混合物对成年褐鳟鱼的影响，并比较分子反应模式与更高层次的生物学反应。成年褐鳟鱼被暴露于从遗留污染场地采集的地下水混合物中 4 天和 21 天。成年褐鳟鱼的红细胞出现明显的微核诱导、生殖能力下降以及肝脏组织学出现一些异常外观。平行的 EcoToxChip 分析显示，大量上调基因和少数下调基因具有补偿反应的特征。三个最富集的途径包括甲状腺内分泌过程、转录和翻译细胞过程以及外源化学物质和活性氧物质代谢。在这些生物学途径中，几个差异调节基因与在褐鳟鱼中观察到的顶端结果有关。我们得出结论，EcoToxChip 分析确定的分子反应有望为顶端结果提供信息，并可以支持复杂污染场地的风险评估。
