The Herbicide Atrazine Activates Endocrine Gene Networks via Non-Steroidal NR5A Nuclear Receptors in Fish and Mammalian Cells

Atrazine (ATR) remains a widely used broadleaf herbicide in the United States despite the fact that this s-chlorotriazine has been linked to reproductive abnormalities in fish and amphibians. Here, using zebrafish we report that environmentally relevant ATR concentrations elevated zcyp19a1 expression encoding aromatase (2.2 µg/L), and increased the ratio of female to male fish (22 µg/L). ATR selectively increased zcyp19a1, a known gene target of the nuclear receptor SF-1 (NR5A1), whereas zcyp19a2, which is estrogen responsive, remained unchanged. Remarkably, in mammalian cells ATR functions in a cell-specific manner to upregulate SF-1 targets and other genes critical for steroid synthesis and reproduction, including Cyp19A1, StAR, Cyp11A1, hCG, FSTL3, LHß, INHα, αGSU, and 11ß-HSD2. Our data appear to eliminate the possibility that ATR directly affects SF-1 DNA- or ligand-binding. Instead, we suggest that the stimulatory effects of ATR on the NR5A receptor subfamily (SF-1, LRH-1, and zff1d) are likely mediated by receptor phosphorylation, amplification of cAMP and PI3K signaling, and possibly an increase in the cAMP-responsive cellular kinase SGK-1, which is known to be upregulated in infertile women. Taken together, we propose that this pervasive and persistent environmental chemical alters hormone networks via convergence of NR5A activity and cAMP signaling, to potentially disrupt normal endocrine development and function in lower and higher vertebrates

Caractérisation d'une implication de la stéroïdogenèse dans le processus de différenciation sexuelle de la gonade chez le poisson zèbre <em>(Danio rerio)</em> à des fins d'études écotoxicologiques

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Caractérisation de nouveaux modèles de poissons zèbres transgéniques pour étudier l’impact de perturbateurs endocriniens sur la différenciation sexuelle du poisson zèbre

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Corrigendum to ‘Refinement of an OECD test guideline for evaluating the effects of endocrine disrupting chemicals on aromatase gene expression and reproduction using novel transgenic cyp19a1a-eGFP zebrafish’ [Aquat. Toxicol. 220 (2020) 105403](S0166445X19308392)(10.1016/j.aquatox.2020.105403)

The authors deeply regret that errors occurred in the original above article. Corrections follow below. - In the 2.7. Vitellogenin ELISA section of the Materials and methods section, the sentence “Standard / samples were pre-incubated … overnight at 4°C.” should read as “Standard / samples were pre-incubated with the primary antibody (1:1 with DR-264 zebrafish anti-VTG antibody diluted to 1:500, Biosense Laboratories, Norway) overnight at 4°C.” - In Figure 2, the authors have inadvertently forgot to apply dilution factors to the circulating E2 concentrations. The correct E2 concentrations can be found on the corrected figure bellow. [Formula presented] - In the 3.4. Circulating estradiol concentrations section of the Results section, the sentence “Nevertheless, a 48% inhibition was seen…concentration (172.6 µg/L)” should now read as “Nevertheless, a 40% inhibition was seen between the fish in the different control groups and the fish exposed to the highest concentration (PCZ 172.6 μg/l).” - In the 3.5. Circulating vitellogenin concentrations section of the Results section, the sentence “A significant decrease was measured in fish … (PCZ 172.6 μg/l).” should read as “A significant decrease was measured in fish exposed to the highest concentration of PCZ, with a fall from 23.40 ± 5.11 mg/ml (DMSO) to 6.10 ± 0.74 mg/ml (PCZ 172.6 μg/l).” - In Figure 3, the unit reported on the Y-axis for the vitellogenin concentrations in mg/ml should read as ng/ml. - In the 4.1. Effect of PCZ on classical endpoints of the OECD TG 229 in cyp19a1a-eGFP zebrafish of the Discussion section, the sentence “From a quantitative point of view, the data….(Doering et al., 2019)” should now read as “From a quantitative point of view, the data we obtained in the cyp19a1a-eGFP zebrafish (40 % decrease of estradiol concentration in the high concentration of PCZ compared to control females, leading to a 65 % decrease of circulating VTG and finally to 60 % less eggs produced) are in perfect adequation with the quantitative relationships existing between all key events of the AOP recently described for wildtype zebrafish (Doering et al., 2019).” These corrections do not affect the conclusions of the article in any way. The authors would like to apologise for any inconvenience caused. DOI of original article: https://doi.org/10.1016/j.aquatox.2020.105403 Nathalie Hinfray © 202

Both aromatase isoforms are expressed in all gonads during sexual differentiation in zebrafish

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New transgenic zebrafish models to study the expression of key steroidgenic enzymes and their perturbation by endocrine disrupting chemicals

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Effect of (xeno)-estrogens on zebrafish P450c17 (C17, 17 alpha-hydroxylase/17, 20-lyase) mRNA and protein expression in gonadal tissue.

PosterInternational audienc

Brain and gonadal aromatases as molecular and biochemical targets of endocrine disrupters in a model species, the zebrafish (Danio rerio).

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