Activation of the hsp70 promoter by environmental inorganic and organic chemicals: relationships with cytotoxicity and lipophilicity.

International audienceStress proteins (heat shock proteins, HSPs) have been proposed as general markers of cellular aggression and their use for environmental monitoring is often suggested. The aim of this work was to study the potency of various environmentally relevant organic and inorganic chemicals to induce the expression of the HSP70 marker. For this purpose, we used an established HeLa cell line containing the chloramphenicol acetyl transferase (CAT) gene under the control of the hsp70 promoter. The screening of three metallic and 15 organic chemicals revealed differences in their capacities to induce the hsp70 promoter. The three metals tested (cadmium, zinc and mercury) were able to induce a stress response. Some organochlorine compounds (chlorophenol derivatives, tetrachlorohydroquinone, 3, 4-dichloroaniline, ethyl parathion and 1-chloro-2,4-dinitrobenzene) induced a response, whereas other common halogenated pesticides or aromatic hydrocarbons (e.g. benzo(a)pyrene, 2, 4-dichlorophenoxyacetic acid, endosulfan, diuron, 4-nonylphenol) did not. The potency to induce hsp70 was significantly correlated to the octanol-water partition coefficient (log K(ow)) of the inducing chemicals, except for 1-chloro-2,4-dinitrobenzene and ethyl parathion. Cytotoxicity assays run in parallel to the induction measurements revealed that the three metals were effective at non cytotoxic doses whereas all organic compounds, except tetrachlorohydroquinone and 1-chloro-2,4-dinitrobenzene, induced the promoter at cytotoxic doses. These results suggest that hsp70 is induced by different mechanisms of toxicity. We propose that this model can be used in mechanistic studies for the detection of toxic effects of certain pollutants

Effects of human pharmaceuticals on cytotoxicity, EROD activity and ROS production in fish hepatocytes.

Pharmaceuticals are found in the aquatic environment but their potential effects on non-target species like fish remain unknown. This in vitro study is a first approach in the toxicity assessment of human drugs on fish. Nine pharmaceuticals were tested on two fish hepatocyte models: primary cultures of rainbow trout hepatocytes (PRTH) and PLHC-1 fish cell line. Cell viability, interaction with cytochrome P450 1A (CYP1A) enzyme and oxidative stress were assessed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrasodium bromide tetrazolium (MTT), 7-ethoxyresorufin-o-deethylase (EROD) and dichlorofluorescein (DCFH-DA) assays, respectively. The tested drugs were clofibrate (CF), fenofibrate (FF), carbamazepine (CBZ), fluoxetine (FX), diclofenac (DiCF), propranolol (POH), sulfamethoxazole (SFX), amoxicillin (AMX) and gadolinium chloride (GdCl(3)). All substances were cytotoxic, except AMX at concentration up to 500 microM. The calculated MTT EC(50) values ranged from 2 microM (CF) to 651 microM (CBZ) in PLHC-1, and from 53 microM (FF) to 962 microM (GdCl(3)) in PRTH. CF, FF, and FX were the most cytotoxic drugs and induced oxidative stress before being cytotoxic. Compared to hepatocytes from human and dog, fish hepatocytes seemed to be more susceptible to the peroxisome proliferators (PPs) CF and FF. In PLHC-1 cells none of the tested drugs induced the EROD activity whereas POH appeared as a weak EROD inducer in PRTH. Moreover, in PRTH, SFX, DiCF, CBZ and to a lesser extend, FF and CF inhibited the basal EROD activity at clearly sublethal concentrations which may be of concern at the biological and chemical levels in a multipollution context

A stable fish reporter cell line to study estrogen receptor transactivation by environmental (xeno)estrogens.

International audienceCross-species differences between human and fish estrogen receptor (ER) binding by environmental chemicals have been reported. To study ER transactivation in a fish cellular context, we stably co-transfected the PLHC-1 fish hepatoma cell line with a rainbow trout estrogen receptor (rtER) and the luciferase reporter gene driven by an estrogen response element (ERE). This new cell model, called PELN-rtER (for PLHC-1-ERE-Luciferase-Neomycin), responded to 17beta-estradiol (E2) in a both concentration- and temperature-dependent manner, as well as to environmental ER ligands from different chemical classes: natural and synthetic estrogens, zearalenone metabolites, genistein, alkyphenoles and benzophenone derivatives. The comparison with other in vitro models, i.e. human reporter cell lines (HELN-rtER, MELN) and vitellogenin induction in primary cultures of rainbow trout hepatocytes, showed an overall higher sensitivity of the human cells for a majority of ligands, except for benzophenone derivatives which were active at similar or lower concentrations in fish cells, suggesting species-specificity for these substances. Correlation analyses suggest that the fish cell line is closer to the trout hepatocyte than to the human cell context, and could serve as a relevant mechanistic tool to study ER activation in fish hepatic cellular context

Anti-androgens act jointly in suppressing spiggin concentrations in androgen-primed female three-spined sticklebacks - Prediction of combined effects by concentration addition

This is the post-print version of the final paper published in Aquatic Toxicology. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2013 Elsevier B.V.Increasing attention is being directed at the role played by anti-androgenic chemicals in endocrine disruption of wildlife within the aquatic environment. The co-occurrence of multiple contaminants with anti-androgenic activity highlights a need for the predictive assessment of combined effects, but information about anti-androgen mixture effects on wildlife is lacking. This study evaluated the suitability of the androgenised female stickleback screen (AFSS), in which inhibition of androgen-induced spiggin production provides a quantitative assessment of anti-androgenic activity, for predicting the effect of a four component mixture of anti-androgens. The anti-androgenic activity of four known anti-androgens (vinclozolin, fenitrothion, flutamide, linuron) was evaluated from individual concentration-response data and used to design a mixture containing each chemical at equipotent concentrations. Across a 100-fold concentration range, a concentration addition approach was used to predict the response of fish to the mixture. Two studies were conducted independently at each of two laboratories. By using a novel method to adjust for differences between nominal and measured concentrations, good agreement was obtained between the actual outcome of the mixture exposure and the predicted outcome. This demonstrated for the first time that androgen receptor antagonists act in concert in an additive fashion in fish and that existing mixture methodology is effective in predicting the outcome, based on concentration-response data for individual chemicals. The sensitivity range of the AFSS assay lies within the range of anti-androgenicity reported in rivers across many locations internationally. The approach taken in our study lays the foundations for understanding how androgen receptor antagonists work together in fish and is essential in informing risk assessment methods for complex anti-androgenic mixtures in the aquatic environment.European Commission and Natural Environment Research Council

Inventaire et évaluation des méthodes biologiques issues de l'écotoxicologie pour la surveillance des milieux aquatiques en vue de leur utilisation dans le cadre de la DCE: COMPTE RENDU DES ACTIVITES DU GROUPE DE TRAVAIL NATIONAL SUR LES BIOESSAIS ANIME PAR L'OFB ET AQUAREF

Dans le cadre des missions du laboratoire de référence sur la surveillance des milieux aquatiques Aquaref, l’OFB et l’INERIS ont coanimé à partir de 2018 un groupe de travail national sur les essais écotoxicologiques (ou bioessais) applicables à la surveillance de la qualité chimique des milieux aquatiques et des rejets aqueux (GT bioessais). Les objectifs de ce GT étaient d’une part, la réalisation d’un inventaire des bioessais disponibles à ce jour pour la caractérisation de l’écotoxicité des milieux aquatiques et des rejets, et d’autre part, l’évaluation des bioessais recensés sur la base de critères scientifiques et technico économiques établis par le GT et la proposition de batteries de bioessais pertinentes et opérationnelles, en lien avec les objectifs de la directive cadre sur l’eau (DCE). Cet exercice de hiérarchisation a permis aussi de distinguer les bioessais les plus adéquats de ceux qui apparaissent moins aisés à mettre en oeuvre en fonction de scénarios d’utilisation prédéfinis.Ce rapport présente l’inventaire des bioessais, les critères d’évaluation retenus, l’évaluation à proprement parler des bioessais inventoriés, ainsi que le classement de bioessais pour deux contextes d’utilisation en lien avec les objectifs DCE : « Evaluation de la qualité des effluents aqueux, impact des rejets sur le milieu récepteur » et « Surveillance générale de la qualité des eauxde surface ». Il représente l’avis du GT et a été rédigé sur la base des différents échanges, des discussions et du travail fourni par les personnes constituant ce GT et représentant différents organismes, universités, entreprises ou laboratoires prestataires

Anti-androgenic activities of environmental pesticides in the MDA-kb2 reporter cell line.

International audiencePesticides have been suspected to act as endocrine disruptive compounds (EDCs) through several mechanisms of action, however data are still needed for a number of currently used pesticides. In the present study, 30 environmental pesticides selected from different chemical classes (azole, carbamate, dicarboximide, oganochlorine, organophosphorus, oxadiazole, phenylureas, pyrazole, pyrimidine, pyrethroid and sulfonylureas) were tested for their ability to alter in vitro the transcriptional activity of the androgen receptor in the MDA-kb2 reporter cell line. The responsiveness of the system was checked by using a panel of reference ligands of androgen and glucocorticoid receptors. When tested alone at concentrations up to 10 muM, none of the studied pesticides were able to induce the reporter gene after a 18 hour exposure. Conversely, co-exposure experiments with 0.1 nM dihydrotestosterone (DHT) allowed identifying 15 active pesticides with IC(50) ranging from 0.2 muM for vinclozolin to 12 muM for fenarimol. Fipronil and bupirimate were here newly described for their AR antagonistic activity

Développement et utilisation d'outils bio-analytiques pour la surveillance des milieux et le contrôle d'enquête. Démarche bio-analytique pour l'identification de polluants émergents dans les milieux aquatiques - Application aux sédiments de l'étude prospective. Rapport final

L’étude prospective réalisée en 2012 a été initiée par la direction de l’eau et de la biodiversité (DEB) du MEDDE dans le cadre de l’action 16 du plan d’action national pour lutter contre la pollution des milieux aquatiques (Plan Micropolluants) prévoyant la mise à jour des listes de substances à surveiller (Botta et Dulio 2014). Elle fait également résonnance à l’étude prospective prévue dans le plan national sur les résidus de médicaments dans les eaux (mai 2011) visant à rechercher des résidus de médicaments dans les eaux. Les résultats de cette étude visent à contribuer à la réflexion qui doit être menée par les agences de l'eau et les offices de l'eau pour mettre à jour la liste des substances pertinentes à surveiller de manière régulière sur un nombre de point limité du RCS, dans leurs futurs programmes de surveillance.Dans le cadre de cette étude, il a été décidé de mettre en oeuvre des outils biologiques innovants sur un nombre restreint de sites (20) pour évaluer la contamination chimique des milieux sur la base de réponses biologiques et déterminer l’opérationnalité de ces outils pour la surveillance. Ces premiers travaux ont fait l’objet d’un rapport en 2014, dressant l’intérêt de tels outils (Aït-Aïssa et al 2014). Dans le présent rapport, nous rapportons l'application des bioessais in vitro et in vivo au sein d'une démarche bio-analytique intégrée pour caractériser la contamination organique des sédiments de l'ensemble des sites métropolitains (120) de l'étude prospective. Cette étude a mis en avant plusieurs résultats significatifs relatifs à la démarche bio-analytique et à la caractérisation des contaminants de type perturbateurs endocriniens et dioxin-like dans les sédiments

Monitoring of dioxin-like, estrogenic and anti-androgenic activities in sediments of the Bizerta lagoon (Tunisia) by means of in vitro cell-based bioassays: contribution of low concentrations of polynuclear aromatic hydrocarbons (PAHs).

International audienceWe used an array of in vitro cell-based bioassays to assess dioxin-like, estrogenic and (anti-)androgenic activities in organic extracts of sediments from the Bizerta lagoon, one of the largest Tunisian lagoons subjected to various anthropogenic and industrial pressures. The sediments were sampled both in winter and summer 2006 in 6 stations differently impacted and in one reference station located in the seawards entrance of Ghar el Melh lagoon. Chemical analyses of the 16 priority PAHs showed that the sediments were low to moderately contaminated (2-537 ng/g dry weight). By using the estrogen- (MELN) and androgen-responsive (MDA-kb2) reporter cell lines, significant estrogenic and anti-androgenic activities were detected only in the Menzel Bourguiba (MB) site, the most contaminated site, both in winter and summer. By using 7-ethoxyresorufin-O-deethylase (EROD) induction in the fish PLHC-1 cell line after both 4 and 24 h of cell exposure, dioxin-like activities were detected in all analysed samples. Dioxin-like activities were higher after 4 h exposure, and varied according to the sites and the sampling season. While highly significant correlation was observed between bioassay- and chemical analyses-derived toxic equivalents (TEQs), PAHs accounted for only a small part (up to 4%) of the detected biological activities, suggesting that other readily metabolised EROD-inducing compounds were present. This study argues for the use of short time exposure to assess biological TEQs in low contaminated samples and provides new induction equivalent factors (IEF(4h)) for 16 PAHs in the PLHC-1 cell line. Finally, our results stress the need to further characterise the nature of organic chemical contamination as well as its long-term impacts on aquatic wildlife in the Bizerta lagoon

Combined effects of environmental xeno-estrogens within multi-component mixtures: Comparison of in vitro human- and zebrafish-based estrogenicity bioassays

EU Seventh Framework Programme; French Ministry of Ecolog