Preliminary investigation of multi-biomarker responses in three-spined stickleback (Gasterosteus aculeatus L.) sampled in contaminated streams

International audienceRecently, the three-spined stickleback (Gasterosteus aculeatus L.) has been proposed as a suitable fish species for detecting both androgen- and estrogen-induced endocrine disruption by environmental pollutants. This relatively pollution-tolerant fish is present in most European streams and small rivers but also coastal and estuarian areas. The purpose of the present field study was to determine the extent to which multiple biomarkers in this fish species could distinguish between streams with different pollution levels. Sticklebacks were sampled in French rivers characterised by various urban, industrial or agricultural contaminations and in outdoor lotic mesocosms as reference site. Physiological parameters including condition factor and liver somatic index, biotransformation enzymes such as 7-ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase, antioxidant enzymes including glutathione peroxidase and total glutathione (GSH) content and lipoperoxidation (as TBARS) showed several differences between sites. For example, fish from an heavily contaminated stream exhibited a 9-fold EROD induction associated to a decrease of GSH and a 3-fold increase of TBARS content in comparison to fish from uncontaminated sites. When fish were transferred from polluted river to clean water, some of these biomarkers rapidly returned to basal levels found in fish in the reference site while others, like TBARS levels were still high after 2 weeks of depuration. Based on multivariate analyses, the battery of biomarkers proved to differentiate all sites, with a very good classification rate for highly contaminated streams. Influence of fish gender and sampling period on biomarker responses was also observed and is discussed. The results of this field study provide additional support for the use of stickleback for in situ multi-biomarker assessment

Copper-induced oxidative stress in three-spined stickleback : relationship with hepatic metal levels

International audienceThe aim of this study was to characterise biomarker responses in three-spined sticklebacks exposed to copper. For this purpose, adult sticklebacks were exposed for 3 weeks to copper sulphate at 0. 25 100 and 200 mug L-1 as Cu. At days 4, 8, 12 and 21. several parameters were measured including liver, gonad and spleen somatic indexes, hepatic biomarkers (catalase (CAT), superoxide dismutase (SOD). glutathione peroxidase (GPx), glutathione (GSH), glutathione-S-transferase (GST) and 7-ethoxyresorufin-O-deethylase (EROD)) and hepatic copper and zinc concentrations. Copper induced a rapid and transient increase of antioxidant enzymes and a depletion of gluiathione content during the first 8 days of exposure. Significant copper and zinc accumulation in fish liver were observed for the two higher exposure concentrations after 8 and 12 days, respectively. This study showed that copper induced an oxidative stress in fish liver before significant metal accumulation in the liver could be detected, suggesting the involvement of differential mechanisms in copper uptake and metabolism. Three-spined stickleback appears to be a sensitive model to stud), oxidative stress induced by metals

Evaluation of an in vitro hsp 70 induction test for toxicity assessment of complex mixtures : comparaison with chemical analyses and ecotoxicity tests

International audienceThe aim of this study was to assess the potential of a human cell line containing the hsp70 promoter linked to the chloramphenicol acetyltransferase reporter gene in evaluating the toxic potential of complex mixtures. Cells were exposed to eluates of industrial wastes and the cellular responses were compared with the metal contents of the samples and with standardized aquatic (microalgal growth inhibition, daphnia Immobilization, bacterial luminescence inhibition, Ceriodaphnia dubia reproduction inhibition) and terrestrial (earthworm lethality, plant growth inhibition) tests. The hsp70 promoter was significantly induced by 11 of 14 samples, with different dose-response patterns. Significant correlations of in vitro induction potency with aquatic ecotoxicity, especially with chronic tests, and with the metal contents of the samples were observed. Our study provides new information on the relevance of hsp70 gene induction as a criterion of toxicity and suggests its usefulness for the detection of toxicity associated with metallic pollution in complex mixtures

Induction of the HSP70 gene promoter by various anticancer drugs

International audienceHeLa cells containing the chloramphenicol acetyl transferase (CAT) gene under the control of the hsp70 promoter have been exposed in vitro to various anticancer drugs. Cisplatin induced CAT production with a dose-effect relationship at a non-cytotoxic dose, whereas no induction was detected with carboplatin. Etoposid induced a significant response at a cytotoxic concentration. The limited positive response with doxorubicin, daunomycin and mitoxantrone was not statistically significant. These chemicals are known to produce reactive oxygen species and induce apoptosis. No induction of the hsp70 promoter could be detected with the other cytostatic compounds that have been tested such as base analogues (5-fluorouracil, cytosine arabinoside 3'-MP), inhibitors of DNA synthesis (amethopterin, aminopterin), antimitotics (vinblastine, colchicine), and alkylating (streptozotocine, carboplatin, melphalan) or intercalating agents (bleomycin). In addition, the role of the transcription inhibitory activity of doxorubicin in this model is evidenced and the consequent question of the suitability of the reporter gene system is discussed. Our results suggest that specific genotoxic compounds are not able to induce the hsp70 promoter, and are in agreement with the concept that stimulation of HSP70 synthesis occurs through a biochemical process involving proteotoxicity

Strengthen the European collaborative environmental research to meet European policy goals for achieving a sustainable, non-toxic environment

To meet the United Nations (UN) sustainable development goals and the European Union (EU) strategy for a non-toxic environment, water resources and ecosystems management require cost-efficient solutions for prevailing complex contamination and multiple stressor exposures. For the protection of water resources under global change conditions, specific research needs for prediction, monitoring, assessment and abatement of multiple stressors emerge with respect to maintaining human needs, biodiversity, and ecosystem services. Collaborative European research seems an ideal instrument to mobilize the required transdisciplinary scientific support and tackle the large-scale dimension and develop options required for implementation of European policies. Calls for research on minimizing society’s chemical footprints in the water–food–energy–security nexus are required. European research should be complemented with targeted national scientific funding to address specific transformation pathways and support the evaluation, demonstration and implementation of novel approaches on regional scales. The foreseeable pressure developments due to demographic, economic and climate changes require solution-oriented thinking, focusing on the assessment of sustainable abatement options and transformation pathways rather than on status evaluation. Stakeholder involvement is a key success factor in collaborative projects as it allows capturing added value, to address other levels of complexity, and find smarter solutions by synthesizing scientific evidence, integrating governance issues, and addressing transition pathways. This increases the chances of closing the value chain by implementing novel solutions. For the water quality topic, the interacting European collaborative projects SOLUTIONS, MARS and GLOBAQUA and the NORMAN network provide best practice examples for successful applied collaborative research including multi-stakeholder involvement. They provided innovative conceptual, modelling and instrumental options for future monitoring and management of chemical mixtures and multiple stressors in European water resources. Advancement of EU water framework directive-related policies has therefore become an option

Adverse effects in wild fish living downstream from pharmaceutical manufacture discharges

International audienceA set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations

EDA-EMERGE: an FP7 initial training network to equip the next generation of young scientists with the skills to address the complexity of environmental contamination with emerging pollutants

The initial training network consortium novel tools in effect-directed analysis to support the identification and monitoring of emerging toxicants on a European scale (EDA-EMERGE) was formed in response to the seventh EU framework program call to train a new generation of young scientists (13 PhD fellows and 1 postdoctoral fellow) in the interdisciplinary techniques required to meet the major challenges in the monitoring, assessment, and management of toxic pollution in European river basins. This 4-year project is of particular relevance considering the multidisciplinary analytical chemistry and biology skills required to investigate the enormous complexity of contamination, effects, and cause-effect relationships. By integrating innovative mode-of-action-based biodiagnostic tools including in vitro and in vivo tests, transgenic organisms, and ‘omics’ techniques with powerful fractionation and cutting edge, analytical, and computational structure elucidation tools, powerful new EDA approaches are being developed for the identification of toxicants in European surface and drinking waters. Innovative method development by young researchers at major European universities, research centers, and private companies has been closely interlinked with a joint European demonstration program, higher-tier EDA, and specialized training courses and secondments. Using a simplified protocol based on existing EDA tools, EDA-EMERGE fellows are also being trained to organize and run international and interdisciplinary sampling and monitoring campaigns within selected European river basin sites. Strong networking between academia, the private sector, and leading regulators in the field of river basin management and pollution management ensures the relevance of the research for practice and excellent employment opportunities for the fellows. Additionally, an internationally composed advisory board has been tasked to introduce new perspectives on monitoring, assessment, and management of emerging pollutants within and outside of Europe. The combination of cutting edge science with specialized training in complimentary soft skills is being offered with a strong emphasis on commercial exploitation and media competence which further enhances the employability of the fellows in research, academia, and beyond.publishedVersio

Mixtures of Chemical Pollutants at European Legislation Safety Concentrations: How Safe Are They?

The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentration

Mixtures of chemical pollutants at European legislation safety concentrations: how safe are they?

The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentrations