State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academic of Science, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, 310058, China.
Chemosphere. 2020 Jun;249:126536. doi: 10.1016/j.chemosphere.2020.126536. Epub 2020 Mar 17.
This study investigated the influences of titanium dioxide nanoparticles (n-TiO) on the thyroid endocrine disruption and neurobehavioral defects induced by pentachlorophenol (PCP) in zebrafish (Danio rerio). Embryos (2 h post-fertilization) were exposed to PCP (0, 3, 10, and 30 μg/L) or in combination with n-TiO (0.1 mg/L) until 6 days post-fertilization. The results showed that n-TiO alone did not affect thyroid hormones levels or transcriptions of related genes. Exposure to PCP significantly decreased thyroid hormone thyroxine (T4) content, thyroid stimulating hormone (TSH) level and transcription of thyroglobulin (tg), but significantly increased 3,5,3'-triiodothyronine (T3) level and upregulation of deiodinase 2 (dio2). In comparison, the co-exposure with n-TiO significantly reduced the content of T3 by depressing the potential targets, tg and dio2. For neurotoxicity, the single and co-exposure resulted in similar effects with significant downregulation of neurodevelopment-related genes (ELAV like RNA Binding Protein 3, elavl3; Growth associated protein-43, gap43; α-tubulin) and inhibited locomotor activity. The results indicated that the presence of n-TiO significantly enhanced the PCP-induced thyroid endocrine disruption but not the neurobehavioral defects in zebrafish larvae.
本研究探讨了纳米二氧化钛（n-TiO）对五氯酚（PCP）诱导的斑马鱼甲状腺内分泌干扰和神经行为缺陷的影响。胚胎（受精后 2 小时）暴露于 PCP（0、3、10 和 30μg/L）或与 n-TiO（0.1mg/L）联合暴露至受精后 6 天。结果表明，n-TiO 单独处理不会影响甲状腺激素水平或相关基因的转录。PCP 暴露显著降低甲状腺激素甲状腺素（T4）含量、促甲状腺激素（TSH）水平和甲状腺球蛋白（tg）的转录，但显著增加 3,5,3'-三碘甲状腺原氨酸（T3）水平并上调脱碘酶 2（dio2）。相比之下，与 n-TiO 共同暴露会通过抑制潜在靶点 tg 和 dio2 来显著降低 T3 的含量。对于神经毒性，单一和共同暴露具有相似的效果，与神经发育相关基因（ELAV 样 RNA 结合蛋白 3，elavl3；生长相关蛋白 43，gap43；α-微管蛋白）的显著下调和运动活性抑制有关。结果表明，n-TiO 的存在显著增强了 PCP 诱导的斑马鱼幼虫甲状腺内分泌干扰，但没有增强神经行为缺陷。
