Fraunhofer Attract Eco'n'OMICs, Fraunhofer Institute for Molecular Biology and Applied Ecology, Schmallenberg, Germany; Department Evolutionary Ecology and Environmental Toxicology, Faculty Biological Sciences, Goethe University Frankfurt, Frankfurt, Germany.
Fraunhofer Attract Eco'n'OMICs, Fraunhofer Institute for Molecular Biology and Applied Ecology, Schmallenberg, Germany.
Chemosphere. 2022 Mar;291(Pt 1):132746. doi: 10.1016/j.chemosphere.2021.132746. Epub 2021 Nov 5.
For specific primary modes of action (MoA) in environmental non-target organisms, EU legislation restricts the usage of active substances of pesticides or biocides. Corresponding regulatory hazard assessments are costly, time consuming and require large numbers of non-human animal studies. Currently, predictive toxicology of development compounds relies on their chemical structure and provides little insights into toxicity mechanisms that precede adverse effects. Using the zebrafish embryo model, we characterized transcriptomic responses to a range of sublethal concentrations of six nerve- and muscle-targeting insecticides with different MoA (abamectin, carbaryl, chlorpyrifos, fipronil, imidacloprid & methoxychlor). Our aim was to identify affected biological processes and suitable biomarker candidates for MoA-specific signatures. Abamectin showed the most divergent signature among the tested insecticides, linked to lipid metabolic processes. Differentially expressed genes (DEGs) after imidacloprid exposure were primarily associated with immune system and inflammation. In total, 222 early responsive genes to either MoA were identified, many related to three major processes: (1) cardiac muscle cell development and functioning (tcap, desma, bag3, hspb1, hspb8, flnca, myoz3a, mybpc2b, actc2, tnnt2c), (2) oxygen transport and hypoxic stress (alas2, hbbe1.1, hbbe1.3, hbbe2, hbae3, igfbp1a, hif1al) and (3) neuronal development and plasticity (npas4a, egr1, btg2, ier2a, vgf). The thyroidal function related gene dio3b was upregulated by chlorpyrifos and downregulated by higher abamectin concentrations. Important regulatory genes for cardiac muscle (tcap) and forebrain development (npas4a) were the most frequently ifferentially expressed across all insecticide treatments. We consider the identified gene sets as useful early warning biomarker candidates, i.e. for developmental toxicity targeting heart and brain in aquatic vertebrates. Our findings provide a better understanding about early molecular events in response to the analyzed MoA. Perceptively, this promotes the development for sensitive and informative biomarker-based in vitro assays for toxicological MoA prediction and AOP refinement, without the suffering of adult fish.
对于环境非靶标生物的特定主要作用模式 (MoA)，欧盟法规限制了杀虫剂或生物杀灭剂的活性物质的使用。相应的监管危害评估既昂贵又耗时，并且需要大量非人类动物研究。目前，发育化合物的预测毒理学依赖于其化学结构，几乎无法深入了解毒性机制，而毒性机制先于不良反应。我们使用斑马鱼胚胎模型，表征了 6 种具有不同 MoA（阿维菌素、甲萘威、毒死蜱、氟虫腈、氯吡虫啉和甲氧氯）的亚致死浓度神经和肌肉靶向杀虫剂的转录组反应。我们的目的是确定受影响的生物过程和适合 MoA 特异性特征的生物标志物候选物。在测试的杀虫剂中，阿维菌素表现出最具差异的特征，与脂质代谢过程有关。氯吡氟虫胺暴露后的差异表达基因 (DEG) 主要与免疫系统和炎症有关。总共鉴定出 222 个对任何 MoA 均有早期反应的基因，其中许多与三个主要过程有关：(1) 心肌细胞发育和功能 (tcap、desma、bag3、hspb1、hspb8、flnca、myoz3a、mybpc2b、actc2、tnnt2c)，(2) 氧气运输和缺氧应激 (alas2、hbbe1.1、hbbe1.3、hbbe2、hbae3、igfbp1a、hif1al) 和 (3) 神经元发育和可塑性 (npas4a、egr1、btg2、ier2a、vgf)。甲状腺功能相关基因 dio3b 被毒死蜱上调，被高浓度阿维菌素下调。心肌 (tcap) 和前脑发育 (npas4a) 的重要调节基因是所有杀虫剂处理中最常差异表达的基因。我们认为所鉴定的基因集是有用的早期预警生物标志物候选物，即针对水生脊椎动物心脏和大脑的发育毒性。我们的发现提供了对分析的 MoA 响应的早期分子事件的更好理解。从感知的角度来看，这促进了基于敏感和信息丰富的生物标志物的毒性 MoA 预测和 AOP 细化的体外测定的发展，而无需使成年鱼类遭受痛苦。
