Laboratory of Environment Biomonitoring, Unit of coastal Ecology and Ecotoxicology, Faculty of Sciences of Bizerte, University of Carthage, 7021, Zarzouna, Tunisia; U1198 MMDN (Molecular Mechanisms of Neurodegenerative Diseases), Inserm (National Institute for Health and Medical Research), MGX (Montpellier GenomiX), BioCampus, University of Montpellier, 34095, Montpellier, France.
Laboratory of Environment Biomonitoring, Unit of coastal Ecology and Ecotoxicology, Faculty of Sciences of Bizerte, University of Carthage, 7021, Zarzouna, Tunisia.
Sci Total Environ. 2021 May 20;770:145272. doi: 10.1016/j.scitotenv.2021.145272. Epub 2021 Jan 21.
The ubiquitous use of ethinylestradiol (EE2), an active constituent of birth control preparations, results in continuous release of this synthetic estrogen to surface waters. Many studies document the untoward effects of EE2 on the endocrine system of aquatic organisms. Effects of environmental EE2 on the nervous system are still poorly documented. We studied effects of pico- to nanomolar concentrations of EE2 on early nervous system development of zebrafish larvae. EE2 disrupted axonal nerve regeneration and hair cell regeneration up to 50%. Gene expression in larval brain tissues showed significantly upregulated expression of target genes, such as estrogen and progesterone receptors, and aromatase B. In contrast, downregulation of the tyrosine hydroxylase, involved in the synthesis of neurotransmitters, occurred concomitant with diminution of proliferating cells. Overall, the size of exposed fish larvae decreased by 25% and their swimming behavior was modified compared to non-treated larvae. EE2 interferes with nervous system development, both centrally and peripherally, with negative effects on regeneration and swimming behavior. Survival of fish and other aquatic species may be at risk in chronically EE2-contaminated environments.
己烯雌酚（EE2）是避孕药的一种活性成分，被广泛使用，导致这种合成雌激素持续释放到地表水中。许多研究记录了 EE2 对水生生物内分泌系统的不良影响。EE2 对神经系统的环境影响仍记录甚少。我们研究了皮克至纳摩尔浓度的 EE2 对斑马鱼幼虫早期神经系统发育的影响。EE2 破坏了高达 50%的轴突神经再生和毛细胞再生。幼虫脑组织中的基因表达显示，雌激素和孕激素受体以及芳香酶 B 等靶基因的表达显著上调。相比之下，参与神经递质合成的酪氨酸羟化酶的下调伴随着增殖细胞的减少。总的来说，暴露于 EE2 的鱼幼虫的大小减少了 25%，其游泳行为与未处理的幼虫相比发生了改变。EE2 会干扰中枢和外周神经系统的发育，对再生和游泳行为产生负面影响。鱼类和其他水生物种的生存可能会在长期受 EE2 污染的环境中受到威胁。
