Tang Tianle, Yang Yang, Chen Yawen, Tang Wenhao, Wang Fuqiang, Diao Xiaoping
College of Environment and Plant Protection, Hainan University, Haikou 570228, China.
School of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571199, China.
Int J Environ Res Public Health. 2015 Oct 16;12(10):13069-84. doi: 10.3390/ijerph121013069.
Bisphenol AF (BPAF) is extensively used as a raw material in industry, resulting in its widespread distribution in the aqueous environment. However, the effect of BPAF on the hypothalamic-pituitary-thyroidal (HPT) axis remains unknown. For elucidating the disruptive effects of BPAF on thyroid function and expression of the representative genes along the HPT axis in zebrafish (Danio rerio) embryos, whole-body total 3,3',5-triiodothyronine (TT3), total 3,5,3',5'-tetraiodothyronine (TT4), free 3,3',5-triiodothyronine (FT3) and free 3,5,3',5'-tetraiodothyronine (FT4) levels were examined following 168 h post-fertilization exposure to different BPAF concentrations (0, 5, 50 and 500 μg/L). The results showed that whole-body TT3, TT4, FT3 and FT4 contents decreased significantly with the BPAF treatment, indicating an endocrine disruption of thyroid. The expression of thyroid-stimulating hormone-β and thyroglobulin genes increased after exposing to 50 μg/L BPAF in seven-day-old larvae. The expressions of thyronine deiodinases type 1, type 2 and transthyretin mRNAs were also significantly up-regulated, which were possibly associated with a deterioration of thyroid function. However, slc5a5 gene transcription was significantly down-regulated at 50 μg/L and 500 μg/L BPAF exposure. Furthermore, trα and trβ genes were down-regulated transcriptionally after BPAF exposure. It demonstrates that BPAF exposure triggered thyroid endocrine toxicity by altering the whole-body contents of thyroid hormones and changing the transcription of the genes involved in the HPT axis in zebrafish larvae.
双酚AF（BPAF）在工业上被广泛用作原材料，导致其在水环境中广泛分布。然而，BPAF对下丘脑 - 垂体 - 甲状腺（HPT）轴的影响尚不清楚。为了阐明BPAF对斑马鱼（Danio rerio）胚胎甲状腺功能以及HPT轴上代表性基因表达的破坏作用，在受精后168小时暴露于不同浓度（0、5、50和500μg/L）的BPAF后，检测了全身总三碘甲状腺原氨酸（TT3）、总甲状腺素（TT4）、游离三碘甲状腺原氨酸（FT3）和游离甲状腺素（FT4）水平。结果表明，随着BPAF处理，全身TT3、TT4、FT3和FT4含量显著降低，表明甲状腺内分泌受到干扰。在7日龄幼虫中，暴露于50μg/L BPAF后，促甲状腺激素β和甲状腺球蛋白基因的表达增加。1型、2型甲状腺素脱碘酶和转甲状腺素蛋白mRNA的表达也显著上调，这可能与甲状腺功能恶化有关。然而，在暴露于50μg/L和500μg/L BPAF时，slc5a5基因转录显著下调。此外，BPAF暴露后trα和trβ基因转录下调。这表明BPAF暴露通过改变斑马鱼幼虫甲状腺激素的全身含量以及改变HPT轴相关基因的转录引发甲状腺内分泌毒性。
