title: Zebrafish-based reporter gene assays reveal different estrogenic activities in river waters compared to a conventional human-derived assay.
abstract: Endocrine disrupting chemicals (EDCs) act on the endocrine system through multiple mechanisms of action, among them interaction with estrogen receptors (ERs) is a well-identified key event in the initiation of adverse outcomes. As the most commonly used estrogen screening assays are either yeast- or human-cell based systems, the question of their (eco)toxicological relevance when assessing risks for aquatic species can be raised. The present study addresses the use of zebrafish (zf) derived reporter gene assays, both in vitro (i.e. zf liver cell lines stably expressing zfERα, zfERβ1 and zfERβ2 subtypes) and in vivo (i.e. transgenic cyp19a1b-GFP zf embryos), to assess estrogenic contaminants in river waters. By investigating 20 French river sites using passive sampling, high frequencies of in vitro zfER-mediated activities in water extracts were measured. Among the different in vitro assays, zfERβ2 assay was the most sensitive and responsive one, enabling the detection of active compounds at all investigated sites. In addition, comparison with a conventional human-based in vitro assay highlighted sites that were able to active zfERs but not human ER, suggesting the occurrence of zf-specific ER ligands. Furthermore, a significant in vivo estrogenic activity was detected at the most active sites in vitro, with a good accordance between estradiol equivalent (E2-EQ) concentrations derived from both in vitro and in vivo assays. Overall, this study shows the relevance and usefulness of such novel zebrafish-based assays as screening tools to monitor estrogenic activities in complex mixtures such as water extracts. It also supports their preferred use compared to human-based assays to assess the potential risks caused by endocrine disruptive chemicals for aquatic species such as fish.
authors: Institut National de l'Environnement Industriel et des risques (INERIS), Unité Ecotoxicologie in vitro et in vivo, Parc Technologique ALATA, BP2, 60550 Verneuil-en-Halatte, France.
authors: Manoj
authors: M
authors: Sonavane
authors: Institut National de l'Environnement Industriel et des risques (INERIS), Unité Ecotoxicologie in vitro et in vivo, Parc Technologique ALATA, BP2, 60550 Verneuil-en-Halatte, France.
authors: Nicolas
authors: N
authors: Creusot
authors: Institut National de l'Environnement Industriel et des risques (INERIS), Unité Ecotoxicologie in vitro et in vivo, Parc Technologique ALATA, BP2, 60550 Verneuil-en-Halatte, France.
authors: Emmanuelle
authors: E
authors: Maillot-Maréchal
authors: AgroParisTech, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thivernal Grignon, France; INRA, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thivernal Grignon, France.
authors: Alexandre
authors: A
authors: Péry
authors: Institut National de l'Environnement Industriel et des risques (INERIS), Unité Ecotoxicologie in vitro et in vivo, Parc Technologique ALATA, BP2, 60550 Verneuil-en-Halatte, France. Electronic address: francois.brion@ineris.fr.
authors: François
authors: F
authors: Brion
authors: Institut National de l'Environnement Industriel et des risques (INERIS), Unité Ecotoxicologie in vitro et in vivo, Parc Technologique ALATA, BP2, 60550 Verneuil-en-Halatte, France. Electronic address: selim.ait-aissa@ineris.fr.
authors: Selim
authors: S
authors: Aїt-Aïssa
mesh_terms: D000818:Animals; D001681:Biological Assay; D002460:Cell Line; D052244:Endocrine Disruptors / Q000032:analysis / Q000633:toxicity*; D004784:Environmental Monitoring / Q000379:methods*; D004958:Estradiol; D004967:Estrogens; D017930:Genes, Reporter; D006801:Humans; D011960:Receptors, Estrogen / Q000378:metabolism; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D015027:Zebrafish
chemical_list: D052244:Endocrine Disruptors; D004967:Estrogens; D011960:Receptors, Estrogen; D014874:Water Pollutants, Chemical; D004958:Estradiol
keywords: (eco)Toxicological relevance; Complex mixtures; Cross-species differences; Estrogen receptor subtypes; Zebrafish assays