摘要
Halobenzoquinones(HBQs) are emerging disinfection byproducts(DBPs) with a widespread presence in drinking water that exhibit much higher cytotoxicity than regulated DBPs. However, the developmental neurotoxicity of HBQs has not been studied in vivo. In this work, we studied the neurotoxicity of HBQs on zebrafish embryos, after exposure to varying concentrations(0-8 μmol/L) of three HBQs, 2,5-dichloro-1,4-benzoquinone(2,5-DCBQ), 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ), and 2,5-dibromo-1,4-benzoquinone(2,5-DBBQ) for 4 to 120 hr post fertilization(hpf). HBQ exposure significantly decreased the locomotor activity of larvae, accompanied by significant reduction of neurotransmitters(dopamine and γ-aminobutyric acid) and acetylcholinesterase activity. Furthermore, the expression of genes involved in neuronal morphogenesis( gfap, α1-tubulin, mbp, and syn-2 α) were downregulated by 4.4-, 5.2-, 3.0-, and 4.5-fold in the 5 μmol/L 2,5-DCBQ group and 2.0-, 1.6-, 2.1-, and 2.3-fold in the 5 μmol/L 2,5-DBBQ group, respectively. Transcriptomic analysis revealed that HBQ exposure affected the signaling pathways of neural development. This study demonstrates the significant neurotoxicity of HBQs in embryonic zebrafish and provides molecular evidence for understanding the potential mechanisms of HBQ neurotoxicity.
基金
the National Natural Science Foundation of China (Nos. 21677062, 21607059 and 21507155)
the Scientific and Technological Innovation Special Project of Jianghan University (No. 2021KJZX002)
the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chairs Program, Alberta Innovates, and Alberta Health for their support
the support of the China Scholarship Council。
