Fu Dingkun, Leef Melanie, Nowak Barbara, Bridle Andrew
Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, TAS, 7250, Australia.
Ecotoxicology. 2017 Jul;26(5):600-612. doi: 10.1007/s10646-017-1793-4. Epub 2017 Mar 28.
Arsenic (As) and mercury (Hg) are ubiquitous elements known to disrupt thyroid function in vertebrates. To explore the underlying mechanisms of Hg and As on the fish thyroid system, we investigated the associations between muscle concentrations of Hg and As with thyroid-related gene transcription in flathead (Platycephalus bassensis) from a contaminated estuary. We sampled fish at several sites to determine the hepatic expression of genes including deiodinases (D1 and D2), transthyretin (TTR), thyroid hormone receptors (TRα and TRβ) and related them to Hg and As levels in the same individuals. Negative correlations were observed between Hg levels and D2, TTR, TRα and TRβ, whereas positive associations were found between As concentrations and TTR and TRβ. These results suggest that Hg and As exposures from environmental pollution affect the regulation of genes important for normal thyroid function in fish. These thyroid-related genes could be used as biomarkers for monitoring environmental thyroid-hormone disrupting chemicals.
砷（As）和汞（Hg）是普遍存在的元素，已知会扰乱脊椎动物的甲状腺功能。为了探究汞和砷对鱼类甲状腺系统的潜在作用机制，我们调查了来自受污染河口的扁头鲉（Platycephalus bassensis）肌肉中汞和砷的浓度与甲状腺相关基因转录之间的关联。我们在多个地点采集鱼类样本，以确定包括脱碘酶（D1和D2）、甲状腺素运载蛋白（TTR）、甲状腺激素受体（TRα和TRβ）等基因的肝脏表达，并将其与同一鱼体中汞和砷的水平相关联。汞水平与D2、TTR、TRα和TRβ之间呈负相关，而砷浓度与TTR和TRβ之间呈正相关。这些结果表明，环境污染中的汞和砷暴露会影响鱼类正常甲状腺功能重要基因的调控。这些甲状腺相关基因可作为监测环境中甲状腺激素干扰化学物质的生物标志物。
