RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic.
Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.
PLoS One. 2018 Aug 29;13(8):e0203087. doi: 10.1371/journal.pone.0203087. eCollection 2018.
The knowledge on environmentally relevant chemicals that may interfere with thyroid signaling is scarce. Here, we present a method for the screening of goitrogens, compounds that disrupt the thyroid gland function, based on the automatic orientation of zebrafish in a glass capillary and a subsequent imaging of reporter gene fluorescence in the thyroid gland of embryos of the transgenic zebrafish line tg(tg:mCherry). The tg(tg:mCherry) reporter gene indicates a compensatory upregulation of thyroglobulin, the thyroid hormone precursor, in response to inhibition of thyroid hormone synthesis. Fish embryos were exposed to a negative control compound (3,4-dichloroaniline), or a concentration series of known goitrogenic compounds (resorcinol, methimazole, potassium perchlorate, 6-propyl-2-thiouracil, ethylenethiourea, phloroglucinol, pyrazole) with maximum exposure concentration selected based on mortality and/or solubility. Exposure to 3,4-dichloroaniline decreased the fluorescence signal. All goitrogenic compounds exhibited clear concentration-dependent inductions of reporter fluorescence 1.4 to 2.6 fold above control levels. Concentration-response modelling was used to calculate goitrogenic potencies based on EC50 values. The new automated method offers an efficient screening approach for goitrogenic activity.
关于可能干扰甲状腺信号的环境相关化学物质的知识还很匮乏。在这里，我们提出了一种基于斑马鱼在玻璃毛细管中自动定向的方法，对甲状腺功能紊乱的致甲状腺肿物质（干扰甲状腺功能的化合物）进行筛选，并用转基因斑马鱼系 tg(tg:mCherry) 的胚胎的甲状腺中的报告基因荧光进行后续成像。tg(tg:mCherry)报告基因表明，甲状腺球蛋白（甲状腺激素前体）的补偿性上调是对甲状腺激素合成抑制的反应。将鱼胚胎暴露于阴性对照化合物（3,4-二氯苯胺）或一系列已知的致甲状腺肿化合物（间苯二酚、甲巯咪唑、高氯酸钾、6-丙基-2-硫代尿嘧啶、乙撑硫脲、根皮苷、吡唑）中，根据死亡率和/或溶解度选择最大暴露浓度的浓度系列。暴露于 3,4-二氯苯胺会降低荧光信号。所有致甲状腺肿化合物均表现出明显的浓度依赖性报告荧光诱导，比对照水平高 1.4 到 2.6 倍。基于 EC50 值，使用浓度反应模型计算致甲状腺肿能力。这种新的自动化方法为致甲状腺肿活性提供了一种有效的筛选方法。
