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Tal T, Myhre O, Fritsche E, Rüegg J, Craenen K, Aiello-Holden K, Agrillo C, Babin PJ, Escher BI, Dirven H, Hellsten K, Dolva K, Hessel E, Heusinkveld HJ, Hadzhiev Y, Hurem S, Jagiello K, Judzinska B, Klüver N, Knoll-Gellida A, Kühne BA, Leist M, Lislien M, Lyche JL, Müller F, Colbourne JK, Neuhaus W, Pallocca G, Seeger B, Scharkin I, Scholz S, Spjuth O, Torres-Ruiz M, Bartmann K. New approach methods to assess developmental and adult neurotoxicity for regulatory use: a PARC work package 5 project. Front Toxicol 2024; 6:1359507. [PMID: 38742231 PMCID: PMC11089904 DOI: 10.3389/ftox.2024.1359507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/18/2024] [Indexed: 05/16/2024] Open
Abstract
In the European regulatory context, rodent in vivo studies are the predominant source of neurotoxicity information. Although they form a cornerstone of neurotoxicological assessments, they are costly and the topic of ethical debate. While the public expects chemicals and products to be safe for the developing and mature nervous systems, considerable numbers of chemicals in commerce have not, or only to a limited extent, been assessed for their potential to cause neurotoxicity. As such, there is a societal push toward the replacement of animal models with in vitro or alternative methods. New approach methods (NAMs) can contribute to the regulatory knowledge base, increase chemical safety, and modernize chemical hazard and risk assessment. Provided they reach an acceptable level of regulatory relevance and reliability, NAMs may be considered as replacements for specific in vivo studies. The European Partnership for the Assessment of Risks from Chemicals (PARC) addresses challenges to the development and implementation of NAMs in chemical risk assessment. In collaboration with regulatory agencies, Project 5.2.1e (Neurotoxicity) aims to develop and evaluate NAMs for developmental neurotoxicity (DNT) and adult neurotoxicity (ANT) and to understand the applicability domain of specific NAMs for the detection of endocrine disruption and epigenetic perturbation. To speed up assay time and reduce costs, we identify early indicators of later-onset effects. Ultimately, we will assemble second-generation developmental neurotoxicity and first-generation adult neurotoxicity test batteries, both of which aim to provide regulatory hazard and risk assessors and industry stakeholders with robust, speedy, lower-cost, and informative next-generation hazard and risk assessment tools.
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Affiliation(s)
- Tamara Tal
- Helmholtz Centre for Environmental Research – UFZ, Chemicals in the Environment Research Section, Leipzig, Germany
- University of Leipzig, Medical Faculty, Leipzig, Germany
| | - Oddvar Myhre
- Norwegian Institute of Public Health – NIPH, Department of Chemical Toxicology, Oslo, Norway
| | - Ellen Fritsche
- IUF – Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
- DNTOX GmbH, Düsseldorf, Germany
- Swiss Centre for Applied Human Toxicology, University of Basel, Basel, Switzerland
| | - Joëlle Rüegg
- Uppsala University, Department of Organismal Biology, Uppsala, Sweden
| | - Kai Craenen
- European Chemicals Agency (ECHA), Helsinki, Finland
| | | | - Caroline Agrillo
- Uppsala University, Department of Organismal Biology, Uppsala, Sweden
| | - Patrick J. Babin
- Université de Bordeaux, Institut National de la Santé et de la Recherche Médicale (INSERM), Maladies Rares: Génétique et Métabolisme (MRGM), Pessac, France
| | - Beate I. Escher
- Helmholtz Centre for Environmental Research – UFZ, Chemicals in the Environment Research Section, Leipzig, Germany
| | - Hubert Dirven
- Norwegian Institute of Public Health – NIPH, Department of Chemical Toxicology, Oslo, Norway
| | | | - Kristine Dolva
- University of Oslo, Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, Olso, Norway
| | - Ellen Hessel
- Dutch Nation Institute for Public Health and the Environment (RIVM), Centre for Health Protection, Bilthoven, Netherlands
| | - Harm J. Heusinkveld
- Dutch Nation Institute for Public Health and the Environment (RIVM), Centre for Health Protection, Bilthoven, Netherlands
| | - Yavor Hadzhiev
- University of Birmingham, Centre for Environmental Research and Justice, Birmingham, UK
| | - Selma Hurem
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Ås, Norway
| | - Karolina Jagiello
- University of Gdansk, Laboratory of Environmental Chemoinformatics, Gdansk, Poland
| | - Beata Judzinska
- University of Gdansk, Laboratory of Environmental Chemoinformatics, Gdansk, Poland
| | - Nils Klüver
- Helmholtz Centre for Environmental Research – UFZ, Chemicals in the Environment Research Section, Leipzig, Germany
| | - Anja Knoll-Gellida
- Université de Bordeaux, Institut National de la Santé et de la Recherche Médicale (INSERM), Maladies Rares: Génétique et Métabolisme (MRGM), Pessac, France
| | - Britta A. Kühne
- University of Veterinary Medicine Hannover, Foundation, Institute for Food Quality and Food Safety, Hannover, Germany
| | - Marcel Leist
- University of Konstanz, In Vitro Toxicology and Biomedicine/CAAT-Europe, Konstanz, Germany
| | - Malene Lislien
- Norwegian Institute of Public Health – NIPH, Department of Chemical Toxicology, Oslo, Norway
| | - Jan L. Lyche
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Ås, Norway
| | - Ferenc Müller
- University of Birmingham, Centre for Environmental Research and Justice, Birmingham, UK
| | - John K. Colbourne
- University of Birmingham, Centre for Environmental Research and Justice, Birmingham, UK
| | - Winfried Neuhaus
- AIT Austrian Institute of Technology GmbH, Competence Unit Molecular Diagnostics, Center Health and Bioresources, Vienna, Austria
- Danube Private University, Faculty of Dentistry and Medicine, Department of Medicine, Krems, Austria
| | - Giorgia Pallocca
- University of Konstanz, In Vitro Toxicology and Biomedicine/CAAT-Europe, Konstanz, Germany
| | - Bettina Seeger
- University of Veterinary Medicine Hannover, Foundation, Institute for Food Quality and Food Safety, Hannover, Germany
| | - Ilka Scharkin
- IUF – Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Stefan Scholz
- Helmholtz Centre for Environmental Research – UFZ, Chemicals in the Environment Research Section, Leipzig, Germany
| | - Ola Spjuth
- Uppsala University and Science for Life Laboratory, Department of Pharmaceutical Biosciences, Uppsala, Sweden
| | - Monica Torres-Ruiz
- Instituto de Salud Carlos III (ISCIII), Centro Nacional de Sanidad Ambiental (CNSA), Environmental Toxicology Unit, Majadahonda, Spain
| | - Kristina Bartmann
- IUF – Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
- DNTOX GmbH, Düsseldorf, Germany
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2
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Kramer L, Schulze T, Klüver N, Altenburger R, Hackermüller J, Krauss M, Busch W. Curated mode-of-action data and effect concentrations for chemicals relevant for the aquatic environment. Sci Data 2024; 11:60. [PMID: 38200014 PMCID: PMC10781676 DOI: 10.1038/s41597-023-02904-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/29/2023] [Indexed: 01/12/2024] Open
Abstract
Chemicals in the aquatic environment can be harmful to organisms and ecosystems. Knowledge on effect concentrations as well as on mechanisms and modes of interaction with biological molecules and signaling pathways is necessary to perform chemical risk assessment and identify toxic compounds. To this end, we developed criteria and a pipeline for harvesting and summarizing effect concentrations from the US ECOTOX database for the three aquatic species groups algae, crustaceans, and fish and researched the modes of action of more than 3,300 environmentally relevant chemicals in literature and databases. We provide a curated dataset ready to be used for risk assessment based on monitoring data and the first comprehensive collection and categorization of modes of action of environmental chemicals. Authorities, regulators, and scientists can use this data for the grouping of chemicals, the establishment of meaningful assessment groups, and the development of in vitro and in silico approaches for chemical testing and assessment.
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Affiliation(s)
- Lena Kramer
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany
| | - Tobias Schulze
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
| | - Nils Klüver
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany
| | - Rolf Altenburger
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany
- RWTH Aachen University, Institute for Environmental Research, 52074, Aachen, Germany
| | - Jörg Hackermüller
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany
- University of Leipzig, Faculty of Mathematics and Computer Science, Ritterstr. 26, 04109, Leipzig, Germany
| | - Martin Krauss
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany
| | - Wibke Busch
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
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3
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Bashirova N, Poppitz D, Klüver N, Scholz S, Matysik J, Alia A. A mechanistic understanding of the effects of polyethylene terephthalate nanoplastics in the zebrafish (Danio rerio) embryo. Sci Rep 2023; 13:1891. [PMID: 36732581 PMCID: PMC9894871 DOI: 10.1038/s41598-023-28712-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
Plastic pollution, especially by nanoplastics (NPs), has become an emerging topic due to the widespread existence and accumulation in the environment. The research on bioaccumulation and toxicity mechanism of NPs from polyethylene terephthalate (PET), which is widely used for packaging material, have been poorly investigated. Herein, we report the first use of high-resolution magic-angle spinning (HRMAS) NMR based metabolomics in combination with toxicity assay and behavioural end points to get systems-level understanding of toxicity mechanism of PET NPs in intact zebrafish embryos. PET NPs exhibited significant alterations on hatching and survival rate. Accumulation of PET NPs in larvae were observed in liver, intestine, and kidney, which coincide with localization of reactive oxygen species in these areas. HRMAS NMR data reveal that PET NPs cause: (1) significant alteration of metabolites related to targeting of the liver and pathways associated with detoxification and oxidative stress; (2) impairment of mitochondrial membrane integrity as reflected by elevated levels of polar head groups of phospholipids; (3) cellular bioenergetics as evidenced by changes in numerous metabolites associated with interrelated pathways of energy metabolism. Taken together, this work provides for the first time a comprehensive system level understanding of toxicity mechanism of PET NPs exposure in intact larvae.
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Affiliation(s)
- Narmin Bashirova
- Institute for Medical Physics and Biophysics, Leipzig University, Leipzig, Germany.,Institute for Analytical Chemistry, Leipzig University, Leipzig, Germany
| | - David Poppitz
- Institute of Chemical Technology, Leipzig University, Leipzig, Germany
| | - Nils Klüver
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Jörg Matysik
- Institute for Analytical Chemistry, Leipzig University, Leipzig, Germany
| | - A Alia
- Institute for Medical Physics and Biophysics, Leipzig University, Leipzig, Germany. .,Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands.
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4
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Thessen AE, Marvel S, Achenbach JC, Fischer S, Haendel MA, Hayward K, Klüver N, Könemann S, Legradi J, Lein P, Leong C, Mylroie JE, Padilla S, Perone D, Planchart A, Prieto RM, Muriana A, Quevedo C, Reif D, Ryan K, Stinckens E, Truong L, Vergauwen L, Vom Berg C, Wilbanks M, Yaghoobi B, Hamm J. Implementation of Zebrafish Ontologies for Toxicology Screening. Front Toxicol 2022; 4:817999. [PMID: 35387429 PMCID: PMC8979167 DOI: 10.3389/ftox.2022.817999] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/24/2022] [Indexed: 01/16/2023] Open
Abstract
Toxicological evaluation of chemicals using early-life stage zebrafish (Danio rerio) involves the observation and recording of altered phenotypes. Substantial variability has been observed among researchers in phenotypes reported from similar studies, as well as a lack of consistent data annotation, indicating a need for both terminological and data harmonization. When examined from a data science perspective, many of these apparent differences can be parsed into the same or similar endpoints whose measurements differ only in time, methodology, or nomenclature. Ontological knowledge structures can be leveraged to integrate diverse data sets across terminologies, scales, and modalities. Building on this premise, the National Toxicology Program’s Systematic Evaluation of the Application of Zebrafish in Toxicology undertook a collaborative exercise to evaluate how the application of standardized phenotype terminology improved data consistency. To accomplish this, zebrafish researchers were asked to assess images of zebrafish larvae for morphological malformations in two surveys. In the first survey, researchers were asked to annotate observed malformations using their own terminology. In the second survey, researchers were asked to annotate the images from a list of terms and definitions from the Zebrafish Phenotype Ontology. Analysis of the results suggested that the use of ontology terms increased consistency and decreased ambiguity, but a larger study is needed to confirm. We conclude that utilizing a common data standard will not only reduce the heterogeneity of reported terms but increases agreement and repeatability between different laboratories. Thus, we advocate for the development of a zebrafish phenotype atlas to help laboratories create interoperable, computable data.
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Affiliation(s)
- Anne E. Thessen
- Center for Health AI, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- *Correspondence: Anne E. Thessen,
| | - Skylar Marvel
- Department of Biological Sciences, Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States
| | - J. C. Achenbach
- Aquatic and Crop Resource Development Research Center, National Research Council of Canada, Halifax, NS, Canada
| | | | - Melissa A. Haendel
- Center for Health AI, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Kimberly Hayward
- Department of Environmental and Molecular Toxicology and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Nils Klüver
- Department Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - Sarah Könemann
- Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Jessica Legradi
- Environment & Health, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Pamela Lein
- Department of Molecular Biosciences, University of California, Davis, Davis, CA, United States
| | - Connor Leong
- Department of Environmental and Molecular Toxicology and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - J. Erik Mylroie
- Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, United States
| | - Stephanie Padilla
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| | - Dante Perone
- Department of Environmental and Molecular Toxicology and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Antonio Planchart
- Center for Human Health and the Environment, and Center for Environmental and Health Effects of PFAS, Biological Sciences, NC State University, Raleigh, NC, United States
| | | | | | | | - David Reif
- Department of Biological Sciences, Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States
| | - Kristen Ryan
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Evelyn Stinckens
- Zebrafishlab, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium
| | - Lisa Truong
- Department of Environmental and Molecular Toxicology and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Lucia Vergauwen
- Zebrafishlab, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium
| | - Colette Vom Berg
- Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Mitch Wilbanks
- Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, United States
| | - Bianca Yaghoobi
- Department of Molecular Biosciences, University of California, Davis, Davis, CA, United States
| | - Jon Hamm
- Integrated Laboratory Systems, LLC, Contractor supporting the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, National Institute of Environmental Health Sciences, Durham, NC, United States
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5
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Henneberger L, Klüver N, Mühlenbrink M, Escher B. Trout and Human Plasma Protein Binding of Selected Pharmaceuticals Informs the Fish Plasma Model. Environ Toxicol Chem 2022; 41:559-568. [PMID: 33201515 DOI: 10.1002/etc.4934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/19/2020] [Accepted: 11/12/2020] [Indexed: 06/11/2023]
Abstract
Concerns are increasing that pharmaceuticals released into the environment pose a risk to nontarget organism such as fish. The fish plasma model is a read-across approach that uses human therapeutic blood plasma concentrations for estimating likely effects in fish. However, the fish plasma model neglects differences in plasma protein binding between fish and humans. Because binding data for fish plasma are scarce, the binding of 12 active pharmaceutical ingredients (APIs; acidic, basic, and neutral) to rainbow trout (Oncorhynchus mykiss) and human plasma was measured using solid-phase microextraction (SPME). The plasma/water distribution ratios (D plasma/w ) of neutral and basic APIs were similar for trout and human plasma, differing by no more than a factor of 2.7 for a given API. For the acidic APIs, the D plasma/w values of trout plasma were much lower than for human plasma, by up to a factor of 71 for naproxen. The lower affinity of the acidic APIs to trout plasma compared with human plasma suggests that the bioavailability of these APIs is higher in trout. Read-across approaches like the fish plasma model should account for differences in plasma protein binding to avoid over- or underestimation of effects in fish. For the acidic APIs, the effect ratio of the fish plasma model would increase by a factor of 5 to 60 if the unbound plasma concentrations were used to calculate the effect ratio. Environ Toxicol Chem 2022;41:559-568. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
| | - Nils Klüver
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | | | - Beate Escher
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
- Center for Applied Geoscience, Eberhard Karls University of Tübingen, Tübingen, Germany
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6
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Ford AT, Ågerstrand M, Brooks BW, Allen J, Bertram MG, Brodin T, Dang Z, Duquesne S, Sahm R, Hoffmann F, Hollert H, Jacob S, Klüver N, Lazorchak JM, Ledesma M, Melvin SD, Mohr S, Padilla S, Pyle GG, Scholz S, Saaristo M, Smit E, Steevens JA, van den Berg S, Kloas W, Wong BBM, Ziegler M, Maack G. The Role of Behavioral Ecotoxicology in Environmental Protection. Environ Sci Technol 2021; 55:5620-5628. [PMID: 33851533 PMCID: PMC8935421 DOI: 10.1021/acs.est.0c06493] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
For decades, we have known that chemicals affect human and wildlife behavior. Moreover, due to recent technological and computational advances, scientists are now increasingly aware that a wide variety of contaminants and other environmental stressors adversely affect organismal behavior and subsequent ecological outcomes in terrestrial and aquatic ecosystems. There is also a groundswell of concern that regulatory ecotoxicology does not adequately consider behavior, primarily due to a lack of standardized toxicity methods. This has, in turn, led to the exclusion of many behavioral ecotoxicology studies from chemical risk assessments. To improve understanding of the challenges and opportunities for behavioral ecotoxicology within regulatory toxicology/risk assessment, a unique workshop with international representatives from the fields of behavioral ecology, ecotoxicology, regulatory (eco)toxicology, neurotoxicology, test standardization, and risk assessment resulted in the formation of consensus perspectives and recommendations, which promise to serve as a roadmap to advance interfaces among the basic and translational sciences, and regulatory practices.
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Affiliation(s)
- Alex T Ford
- University of Portsmouth, Portsmouth, United Kingdom
| | - Marlene Ågerstrand
- Department of Environmental Science, Stockholm University, Stockholm, Sweden
| | - Bryan W Brooks
- Department of Environmental Science, Institute of Biomedical Studies, Baylor University, Waco, Texas 76706, United States
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, China
| | - Joel Allen
- U.S. EPA Office of Research and Development, Cincinnati, Ohio 45268, United States
| | | | - Tomas Brodin
- Swedish University of Agricultural Sciences, Umeå, Sweden
| | - ZhiChao Dang
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Utrecht, The Netherlands
| | | | - René Sahm
- German Environment Agency (UBA), Dessau, Germany
| | - Frauke Hoffmann
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | | | | | - Nils Klüver
- Environmental Research Center (UFZ), Leipzig, Germany
| | - James M Lazorchak
- U.S. EPA Office of Research and Development, Cincinnati, Ohio 45268, United States
| | - Mariana Ledesma
- Swedish Chemicals Agency (KemI), Sundbyberg, Stockholms Lan, Sweden
| | - Steven D Melvin
- Australian Rivers Institute, Griffith University, Southport, Australia
| | - Silvia Mohr
- German Environment Agency (UBA), Dessau, Germany
| | - Stephanie Padilla
- Center for Computational Toxicology and Exposure, U.S. EPA, Durham, North Carolina, United States
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Canada
| | - Stefan Scholz
- Swedish Chemicals Agency (KemI), Sundbyberg, Stockholms Lan, Sweden
| | - Minna Saaristo
- Environment Protection Authority Victoria (EPA), Carlton, Australia
| | - Els Smit
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Utrecht, The Netherlands
| | - Jeffery A Steevens
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, Missouri 65201, United States
| | | | - Werner Kloas
- Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Bob B M Wong
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michael Ziegler
- Animal Physiological Ecology, University of Tübingen, Tübingen, Germany
| | - Gerd Maack
- German Environment Agency (UBA), Dessau, Germany
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7
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Fischer FC, Abele C, Henneberger L, Klüver N, König M, Mühlenbrink M, Schlichting R, Escher BI. Cellular Metabolism in High-Throughput In Vitro Reporter Gene Assays and Implications for the Quantitative In Vitro–In Vivo Extrapolation. Chem Res Toxicol 2020; 33:1770-1779. [DOI: 10.1021/acs.chemrestox.0c00037] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Fabian C. Fischer
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Cedric Abele
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Luise Henneberger
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Nils Klüver
- Department Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Maria König
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Marie Mühlenbrink
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Rita Schlichting
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Beate I. Escher
- Department Cell Toxicology, Helmholtz Centre for Environmental Research—UFZ, Permoserstraße 15, 04318 Leipzig, Germany
- Centre for Applied Geoscience, Eberhard Karls University Tübingen, 72074 Tübingen, Germany
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8
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Escher BI, Abagyan R, Embry M, Klüver N, Redman AD, Zarfl C, Parkerton TF. Recommendations for Improving Methods and Models for Aquatic Hazard Assessment of Ionizable Organic Chemicals. Environ Toxicol Chem 2020; 39:269-286. [PMID: 31569266 DOI: 10.1002/etc.4602] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/04/2019] [Accepted: 09/20/2019] [Indexed: 05/19/2023]
Abstract
Ionizable organic chemicals (IOCs) such as organic acids and bases are an important substance class requiring aquatic hazard evaluation. Although the aquatic toxicity of IOCs is highly dependent on the water pH, many toxicity studies in the literature cannot be interpreted because pH was not reported or not kept constant during the experiment, calling for an adaptation and improvement of testing guidelines. The modulating influence of pH on toxicity is mainly caused by pH-dependent uptake and bioaccumulation of IOCs, which can be described by ion-trapping and toxicokinetic models. The internal effect concentrations of IOCs were found to be independent of the external pH because of organisms' and cells' ability to maintain a stable internal pH milieu. If the external pH is close to the internal pH, existing quantitative structure-activity relationships (QSARs) for neutral organics can be adapted by substituting the octanol-water partition coefficient by the ionization-corrected liposome-water distribution ratio as the hydrophobicity descriptor, demonstrated by modification of the target lipid model. Charged, zwitterionic and neutral species of an IOC can all contribute to observed toxicity, either through concentration-additive mixture effects or by interaction of different species, as is the case for uncoupling of mitochondrial respiration. For specifically acting IOCs, we recommend a 2-step screening procedure with ion-trapping/QSAR models used to predict the baseline toxicity, followed by adjustment using the toxic ratio derived from in vitro systems. Receptor- or plasma-binding models also show promise for elucidating IOC toxicity. The present review is intended to help demystify the ecotoxicity of IOCs and provide recommendations for their hazard and risk assessment. Environ Toxicol Chem 2020;39:269-286. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
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Affiliation(s)
- Beate I Escher
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
- Center for Applied Geoscience, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Ruben Abagyan
- Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA
| | - Michelle Embry
- Health and Environmental Sciences Institute, Washington, DC, USA
| | - Nils Klüver
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | | | - Christiane Zarfl
- Center for Applied Geoscience, Eberhard Karls University of Tübingen, Tübingen, Germany
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9
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Bittner L, Klüver N, Henneberger L, Mühlenbrink M, Zarfl C, Escher BI. Combined Ion-Trapping and Mass Balance Models To Describe the pH-Dependent Uptake and Toxicity of Acidic and Basic Pharmaceuticals in Zebrafish Embryos ( Danio rerio). Environ Sci Technol 2019; 53:7877-7886. [PMID: 31177773 DOI: 10.1021/acs.est.9b02563] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The aim of the current study was to understand and develop models to predict the pH-dependent toxicity of ionizable pharmaceuticals in embryos of the zebrafish Danio rerio. We found a higher uptake and toxicity with increasing neutral fraction of acids (diclofenac, genistein, naproxen, torasemide, and warfarin) and bases (metoprolol and propranolol). Simple mass balance models accounting for the partitioning to lipids and proteins in the zebrafish embryo were found to be suitable to predict the bioconcentration after 96 h of exposure if pH values did not differ much from the internal pH of 7.55. For other pH values, a kinetic ion-trap model for the zebrafish embryo explained the pH dependence of biouptake and toxicity. The total internal lethal concentrations killing 50% of the zebrafish embryos (ILC50) were calculated from the measured BCF and LC50. The resulting ILC50 were independent of external pH. Critical membrane concentrations were deduced by an internal mass balance model, and apart from diclofenac, whose specific toxicity in fish had already been established, all pharmaceuticals were confirmed to act as baseline toxicants in zebrafish.
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Affiliation(s)
- Lisa Bittner
- Helmholtz Centre for Environmental Research - UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Nils Klüver
- Helmholtz Centre for Environmental Research - UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Luise Henneberger
- Helmholtz Centre for Environmental Research - UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Marie Mühlenbrink
- Helmholtz Centre for Environmental Research - UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Christiane Zarfl
- Eberhard Karls University of Tübingen , Center for Applied Geoscience , Hölderlinstrasse 12 , 72074 Tübingen , Germany
| | - Beate I Escher
- Helmholtz Centre for Environmental Research - UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
- Eberhard Karls University of Tübingen , Center for Applied Geoscience , Hölderlinstrasse 12 , 72074 Tübingen , Germany
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10
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Bittner L, Teixidó E, Keddi I, Escher BI, Klüver N. pH-Dependent Uptake and Sublethal Effects of Antihistamines in Zebrafish (Danio rerio) Embryos. Environ Toxicol Chem 2019; 38:1012-1022. [PMID: 30779379 DOI: 10.1002/etc.4395] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/19/2019] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
Reported off-target effects of antihistamines in humans draw interest in ecotoxicity testing of first- and second-generation antihistamines, the latter of which have fewer reported side effects in humans. Because antihistamines are ionizable compounds, the pH influences uptake and toxicity and thus is highly relevant when conducting toxicity experiments. Zebrafish embryo toxicity tests were performed with the 3 first-generation antihistamines ketotifen, doxylamine, and dimethindene and the 2 second-generation antihistamines cetirizine and levocabastine at pH 5.5, 7.0, and 8.0. We detected effects on survival, phenotype, swimming activity, and heart rate for 4 antihistamines with the exception of levocabastine, which did not show any lethal or sublethal effects. When compared to lethal concentrations, effect concentrations neither of phenotype malformation nor of swimming activity or heart rate deviated by more than a factor of 10 from lethal concentrations, indicating that all sublethal effects were fairly nonspecific. First-generation antihistamines are weak bases and showed decreasing external effect concentrations with increasing neutral fraction, accompanied by increased uptake in the fish embryo. As a result, internal effect concentrations were independent from external pH. The pH-dependent toxicity originates from speciation-dependent uptake, with neutral species taken up in higher amounts than the corresponding ionic species. Cetirizine, which shifts from a zwitterionic to an anionic state in the measured pH range, did not show any pH-dependent uptake or toxicity. Environ Toxicol Chem 2019;00:1-11. © 2019 SETAC.
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Affiliation(s)
- Lisa Bittner
- Department Cell Toxicology, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
| | - Elisabet Teixidó
- Department Bioanalytical Toxicology, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
| | - Isabel Keddi
- Department Cell Toxicology, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
| | - Beate I Escher
- Department Cell Toxicology, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
- Department Environmental Toxicology, Center for Applied Geoscience, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Nils Klüver
- Department Cell Toxicology, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
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11
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Klüver N, Bittermann K, Escher BI. QSAR for baseline toxicity and classification of specific modes of action of ionizable organic chemicals in the zebrafish embryo toxicity test. Aquat Toxicol 2019; 207:110-119. [PMID: 30557756 DOI: 10.1016/j.aquatox.2018.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 12/03/2018] [Accepted: 12/04/2018] [Indexed: 05/06/2023]
Abstract
The fish embryo toxicity (FET) test with the zebrafish Danio rerio is widely used to assess the acute toxicity of chemicals thereby serving as animal alternative to the acute fish toxicity test. The minimal toxicity of neutral chemicals in the FET can be predicted with a previously published Quantitative Structure-Activity Relationship (QSAR) based on the liposome-water partition coefficient Klipw. Such a QSAR may serve to plan toxicity testing and to evaluate whether an observed effect is caused by a specific mode of action (MoA). The applicability domain of this QSAR was extended to ionizable organic chemicals (IOC) without any modification of slope and intercept simply by replacing the Klipw with the speciation-corrected liposome-water distribution ratio (Dlipw(pH)) as descriptor for the uptake into the embryo. FET LC50 values of IOCs were extracted from an existing FET database and published literature. IOCs were selected that are present concomitantly as neutral and charged, species, i.e., acids with an acidity constant pKa <10 and bases with pKa>5. IOCs were grouped according to their putative MoA of acute aquatic toxicity. The toxic ratios (TR) in the FET were derived by of the experimental FET-LC50 in comparison with the baseline toxicity QSAR. Baseline toxicants were confirmed to align well with the FET baseline toxicity QSAR (TR < 10). Chemicals identified to act as specific or reactive chemicals with the toxic ratio analysis in the FET test (TR > 10) were generally consistent with MoA classification for acute fish toxicity with a few exceptions that were suspected to have had issues with the stability of the pH during testing. One critical aspect for the effect analysis of ionizable chemicals is the pH, since the difference between pH and pKa determines the speciation and thereby the Dlipw(pH).
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Affiliation(s)
- Nils Klüver
- UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Kai Bittermann
- UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Beate I Escher
- UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany; Eberhard Karls University Tübingen, Center for Applied Geoscience, Environmental Toxicology Hölderlinstr. 12, 72074, Tübingen, Germany
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12
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Leuthold D, Klüver N, Altenburger R, Busch W. Can Environmentally Relevant Neuroactive Chemicals Specifically Be Detected with the Locomotor Response Test in Zebrafish Embryos? Environ Sci Technol 2019; 53:482-493. [PMID: 30516976 DOI: 10.1021/acs.est.8b04327] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Chemicals considered as neuroactive (such as certain pesticides, pharmaceuticals, and industrial chemicals) are among the largest groups of bioactive substances recently detected in European rivers. However, the determination of nervous-system-specific effects has been limited using in vitro tests or conventional end points including lethality. Thus, neurobehavioral tests using in vivo models (e.g., zebrafish embryo) have been proposed as complementary approaches. To investigate the specificity and sensitivity of a light-dark transition locomotor response (LMR) test in 4 to 5 days post fertilization zebrafish with respect to different modes of action (MoAs), we analyzed a set of 18 environmentally relevant compounds with various anticipated MoAs. We found that exposure-induced behavioral alterations were reproducible and dependent on concentration and time. Comparative and quantitative analyses of the obtained locomotor patterns revealed that behavioral effects were not restricted to compounds primarily known to target the nervous system. A clear distinction of MoAs based on locomotor patterns was not possible for most compounds. Furthermore, chemicals with an anticipated same MoA did not necessarily provoke similar behavioral phenotypes. Finally, we determined an increased sensitivity (≥10-fold) compared to observed mortality in the LMR assay for five of eight neuroactive chemicals as opposed to non-neuroactive compounds.
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Bittner L, Teixido E, Seiwert B, Escher BI, Klüver N. Influence of pH on the uptake and toxicity of β-blockers in embryos of zebrafish, Danio rerio. Aquat Toxicol 2018; 201:129-137. [PMID: 29906695 DOI: 10.1016/j.aquatox.2018.05.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/24/2018] [Accepted: 05/26/2018] [Indexed: 05/22/2023]
Abstract
ß-Blockers are weak bases with acidity constants related to their secondary amine group. At environmental pH they are protonated with the tendency to shift to their neutral species at more alkaline pH. Here we studied the influence of pH from 5.5 to 8.6 on the toxicity of the four ß-blockers atenolol, metoprolol, labetalol and propranolol in zebrafish embryos, relating toxicity not only in a conventional way to external aqueous concentrations but also to measured internal concentrations. Besides lethality, we evaluated changes in swimming activity and heartbeat, using the Locomotor Response (LMR) method and the Vertebrate Automated Screening Technology (VAST) for high throughput imaging. Effects of metoprolol, labetalol and propranolol were detected on phenotype, heart rate and swimming activity. External effect concentrations decreased with increasing neutral fraction for all three pharmaceuticals, attributed by an enhanced uptake of the neutral species in comparison to the corresponding charged form. The LC50 of metoprolol decreased by a factor of 35 from 1.91 mM with almost complete cationic state at pH 7.0 to 0.054 mM with 8% neutral fraction at pH 8.6. For propranolol the LC50 of 2.42 mM at pH 5.5 was even 100 fold higher than the LC50 at pH 8 with 0.023 mM where 3% were neutral fraction. No effects were detected in the zebrafish embryo exposed to atenolol. The internal concentrations for metoprolol and propranolol were quantified at non-toxic concentrations and at the LC10. Apparent bioconcentration factors (BCF) ranged from 1.96 at pH 7.0 to 32.0 at pH 8.6 for metoprolol and from 1.86 at pH 5.5 to 169 at pH 8.0 for propranolol. The BCFs served to predict the internal effect concentrations from the measured external effect concentrations. Internal effect concentrations of metoprolol and propranolol were in a similar range for all pH-values and for all endpoints. Interestingly, the internal effect concentrations were in the internal concentration range of baseline toxicity, which suggests that the effects of the ß-blockers are rather unspecific, even for sublethal effects on heart rate. In summary, our data confirm that the pH-dependent toxicity related to external concentrations can be explained by toxicokinetic effects and that the internal effect concentrations are pH-independent.
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Affiliation(s)
- Lisa Bittner
- Department Cell Toxicology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Elisabet Teixido
- Department Bioanalytical Toxicology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Bettina Seiwert
- Department Analytical Chemistry, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Beate I Escher
- Department Cell Toxicology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany; Environmental Toxicology, Centre for Applied Geoscience, Eberhard-Karls University, Hölderlinstr. 12, 72074 Tübingen, Germany
| | - Nils Klüver
- Department Cell Toxicology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany.
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Sobanska M, Scholz S, Nyman AM, Cesnaitis R, Gutierrez Alonso S, Klüver N, Kühne R, Tyle H, de Knecht J, Dang Z, Lundbergh I, Carlon C, De Coen W. Applicability of the fish embryo acute toxicity (FET) test (OECD 236) in the regulatory context of Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH). Environ Toxicol Chem 2018; 37:657-670. [PMID: 29226368 DOI: 10.1002/etc.4055] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/11/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
In 2013 the Organisation for Economic Co-operation and Development (OECD) test guideline (236) for fish embryo acute toxicity (FET) was adopted. It determines the acute toxicity of chemicals to embryonic fish. Previous studies show a good correlation of FET with the standard acute fish toxicity (AFT) test; however, the potential of the FET test to predict AFT, which is required by the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation (EC 1907/2006) and the Classification, Labelling and Packaging (CLP) Regulation (EC 1272/2008), has not yet been fully clarified. In 2015 the European Chemicals Agency (ECHA) requested that a consultant perform a scientific analysis of the applicability of FET to predict AFT. The purpose was to compare the toxicity of substances to fish embryos and to adult fish, and to investigate whether certain factors (e.g., physicochemical properties, modes of action, or chemical structures) could be used to define the applicability boundaries of the FET test. Given the limited data availability, the analysis focused on organic substances. The present critical review summarizes the main findings and discusses regulatory application of the FET test under REACH. Given some limitations (e.g., neurotoxic mode of action) and/or remaining uncertainties (e.g., deviation of some narcotic substances), it has been found that the FET test alone is currently not sufficient to meet the essential information on AFT as required by the REACH regulation. However, the test may be used within weight-of-evidence approaches together with other independent, relevant, and reliable sources of information. The present review also discusses further research needs that may overcome the remaining uncertainties and help to increase acceptance of FET as a replacement for AFT in the future. For example, an increase in the availability of data generated according to OECD test guideline 236 may provide evidence of a higher predictive power of the test. Environ Toxicol Chem 2018;37:657-670. © 2017 SETAC.
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Affiliation(s)
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | | | | | | | - Nils Klüver
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Ralph Kühne
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Henrik Tyle
- Danish Environmental Protection Agency, Copenhagen, Denmark
| | - Joop de Knecht
- Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Zhichao Dang
- Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | | | | | - Wim De Coen
- European Chemicals Agency, Helsinki, Finland
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15
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Baumer A, Bittermann K, Klüver N, Escher BI. Baseline toxicity and ion-trapping models to describe the pH-dependence of bacterial toxicity of pharmaceuticals. Environ Sci Process Impacts 2017; 19:901-916. [PMID: 28574566 DOI: 10.1039/c7em00099e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In numerous studies on the toxicity of ionisable organic chemicals, it has been shown that the toxicity was typically higher, when larger fractions of the neutral species were present. This observation was explained in some cases by slower uptake of charged species. In other cases it was suggested that the neutral species has intrinsically higher toxicity than the charged species or is alone responsible for the toxicity. However, even permanently charged and organic chemicals with multiple acid and base functional groups and zwitterions are toxic. We set out to reconcile the divergent views and to compare the various existing models for describing the pH-dependence of toxicity with the goal to derive one model that is valid independent of the type and number of charges on the molecule. To achieve this goal we measured the cytotoxicity of 18 acidic, 15 basic and 9 multiprotic/zwitterionic pharmaceuticals at pH 5.5 to pH 9 with the bioluminescence inhibition test using Aliivibrio fischeri (Microtox assay). This assay is useful for an evaluation of various models to describe pH-dependent toxicity because the majority of chemicals act as baseline toxicants in this 30 min cytotoxicity assay. Therefore baseline toxicity with constant membrane concentrations of the sum of all chemical species of approximately 200 mmol kglip-1 served for the validation of the suitability of the various tested models. We confirmed that most tested pharmaceuticals acted as baseline toxicants in this assay at all examined pH values, when toxicity was modeled with a mixture model of concentration addition between the neutral species and all charged species. An ion trapping model, that assumes that the membrane permeability of charged species is kinetically limited, improved model predictions for some pharmaceuticals and pH values. However, neither unhindered uptake nor no uptake of the charged species were ideal models; the reality lies presumably between the two limiting cases with a slower uptake of the charged species than the neutral species. For practical applications a previously developed QSAR model with the ionisation-corrected liposome-water distribution ratio as the sole physicochemical descriptor proved to be generally applicable for all ionisable organic chemicals including those with multiple charges and zwitterions.
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Affiliation(s)
- Andreas Baumer
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany.
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Escher BI, Baumer A, Bittermann K, Henneberger L, König M, Kühnert C, Klüver N. General baseline toxicity QSAR for nonpolar, polar and ionisable chemicals and their mixtures in the bioluminescence inhibition assay with Aliivibrio fischeri. Environ Sci Process Impacts 2017; 19:414-428. [PMID: 28197603 DOI: 10.1039/c6em00692b] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The Microtox assay, a bioluminescence inhibition assay with the marine bacterium Aliivibrio fischeri, is one of the most popular bioassays for assessing the cytotoxicity of organic chemicals, mixtures and environmental samples. Most environmental chemicals act as baseline toxicants in this short-term screening assay, which is typically run with only 30 min of exposure duration. Numerous Quantitative Structure-Activity Relationships (QSARs) exist for the Microtox assay for nonpolar and polar narcosis. However, typical water pollutants, which have highly diverse structures covering a wide range of hydrophobicity and speciation from neutral to anionic and cationic, are often outside the applicability domain of these QSARs. To include all types of environmentally relevant organic pollutants we developed a general baseline toxicity QSAR using liposome-water distribution ratios as descriptors. Previous limitations in availability of experimental liposome-water partition constants were overcome by reliable prediction models based on polyparameter linear free energy relationships for neutral chemicals and the COSMOmic model for charged chemicals. With this QSAR and targeted mixture experiments we could demonstrate that ionisable chemicals fall in the applicability domain. Most investigated water pollutants acted as baseline toxicants in this bioassay, with the few outliers identified as uncouplers or reactive toxicants. The main limitation of the Microtox assay is that chemicals with a high melting point and/or high hydrophobicity were outside of the applicability domain because of their low water solubility. We quantitatively derived a solubility cut-off but also demonstrated with mixture experiments that chemicals inactive on their own can contribute to mixture toxicity, which is highly relevant for complex environmental mixtures, where these chemicals may be present at concentrations below the solubility cut-off.
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Affiliation(s)
- Beate I Escher
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany. and Eberhard Karls University Tübingen, Environmental Toxicology, Center for Applied Geosciences, 72074 Tübingen, Germany
| | - Andreas Baumer
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany. and Department of Clinical Pharmacy, Leipzig University, Eilenburger Str. 15a, 04317 Leipzig, Germany
| | - Kai Bittermann
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany.
| | - Luise Henneberger
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany.
| | - Maria König
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany.
| | - Christin Kühnert
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany.
| | - Nils Klüver
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, DE-04318 Leipzig, Germany.
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17
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Escher BI, Hackermüller J, Polte T, Scholz S, Aigner A, Altenburger R, Böhme A, Bopp SK, Brack W, Busch W, Chadeau-Hyam M, Covaci A, Eisenträger A, Galligan JJ, Garcia-Reyero N, Hartung T, Hein M, Herberth G, Jahnke A, Kleinjans J, Klüver N, Krauss M, Lamoree M, Lehmann I, Luckenbach T, Miller GW, Müller A, Phillips DH, Reemtsma T, Rolle-Kampczyk U, Schüürmann G, Schwikowski B, Tan YM, Trump S, Walter-Rohde S, Wambaugh JF. From the exposome to mechanistic understanding of chemical-induced adverse effects. Environ Int 2017; 99:97-106. [PMID: 27939949 PMCID: PMC6116522 DOI: 10.1016/j.envint.2016.11.029] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/27/2016] [Accepted: 11/29/2016] [Indexed: 05/17/2023]
Abstract
The exposome encompasses an individual's exposure to exogenous chemicals, as well as endogenous chemicals that are produced or altered in response to external stressors. While the exposome concept has been established for human health, its principles can be extended to include broader ecological issues. The assessment of exposure is tightly interlinked with hazard assessment. Here, we explore if mechanistic understanding of the causal links between exposure and adverse effects on human health and the environment can be improved by integrating the exposome approach with the adverse outcome pathway (AOP) concept that structures and organizes the sequence of biological events from an initial molecular interaction of a chemical with a biological target to an adverse outcome. Complementing exposome research with the AOP concept may facilitate a mechanistic understanding of stress-induced adverse effects, examine the relative contributions from various components of the exposome, determine the primary risk drivers in complex mixtures, and promote an integrative assessment of chemical risks for both human and environmental health.
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Affiliation(s)
- Beate I Escher
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Jörg Hackermüller
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Tobias Polte
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Stefan Scholz
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Achim Aigner
- Leipzig University, Rudolf Boehm Institute for Pharmacology & Toxicology, Clinical Pharmacology, Haertelstr. 16-18, 04107 Leipzig, Germany
| | - Rolf Altenburger
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Alexander Böhme
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Stephanie K Bopp
- European Commission Joint Research Centre, Directorate F - Health, Consumers and Reference Materials, Via E. Fermi 2749, 21027 Ispra, VA, Italy
| | - Werner Brack
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Wibke Busch
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Marc Chadeau-Hyam
- University London, Imperial College, Department Epidemiology & Biostatistics, School of Public Health, St Marys Campus, Norfolk Place, London W2 1PG, England, United Kingdom
| | - Adrian Covaci
- Toxicological Center, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk-Antwerp, Belgium
| | | | - James J Galligan
- Vanderbilt University, School of Medicine, A.B. Hancock Jr. Memorial Laboratory for Cancer Research, Department Biochemistry, Nashville, TN 37232, USA
| | - Natalia Garcia-Reyero
- US Army Engineer Research & Development Center, Vicksburg, MS, USA; Mississippi State University, Starkville, MS, USA
| | - Thomas Hartung
- Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA; University of Konstanz, Germany
| | - Michaela Hein
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Gunda Herberth
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Annika Jahnke
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Jos Kleinjans
- Maastricht University, Department Toxicogenomics, 6200 MD Maastricht, The Netherlands
| | - Nils Klüver
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Martin Krauss
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Marja Lamoree
- Vrije Universiteit, Faculty of Earth & Life Sciences, Institute for Environmental Studies, 1081 HV Amsterdam, The Netherlands
| | - Irina Lehmann
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Till Luckenbach
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Gary W Miller
- Dept of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Andrea Müller
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - David H Phillips
- King's College London, MRC-PHE Centre for Environment & Health, Analytical & Environmental Sciences Division, London SE1 9NH, England, United Kingdom
| | - Thorsten Reemtsma
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Ulrike Rolle-Kampczyk
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Gerrit Schüürmann
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany; Technical University Bergakademie Freiberg, Institute for Organic Chemistry, 09596 Freiberg, Germany
| | | | - Yu-Mei Tan
- US EPA, National Exposure Research Laboratory, Research Triangle Park, NC 27711, USA
| | - Saskia Trump
- Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | | | - John F Wambaugh
- US EPA, National Center for Computational Toxicology, Research Triangle Park, NC 27711, USA
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Klüver N, Vogs C, Altenburger R, Escher BI, Scholz S. Development of a general baseline toxicity QSAR model for the fish embryo acute toxicity test. Chemosphere 2016; 164:164-173. [PMID: 27588575 DOI: 10.1016/j.chemosphere.2016.08.079] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/15/2016] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
Fish embryos have become a popular model in ecotoxicology and toxicology. The fish embryo acute toxicity test (FET) with the zebrafish embryo was recently adopted by the OECD as technical guideline TG 236 and a large database of concentrations causing 50% lethality (LC50) is available in the literature. Quantitative Structure-Activity Relationships (QSARs) of baseline toxicity (also called narcosis) are helpful to estimate the minimum toxicity of chemicals to be tested and to identify excess toxicity in existing data sets. Here, we analyzed an existing fish embryo toxicity database and established a QSAR for fish embryo LC50 using chemicals that were independently classified to act according to the non-specific mode of action of baseline toxicity. The octanol-water partition coefficient Kow is commonly applied to discriminate between non-polar and polar narcotics. Replacing the Kow by the liposome-water partition coefficient Klipw yielded a common QSAR for polar and non-polar baseline toxicants. This developed baseline toxicity QSAR was applied to compare the final mode of action (MOA) assignment of 132 chemicals. Further, we included the analysis of internal lethal concentration (ILC50) and chemical activity (La50) as complementary approaches to evaluate the robustness of the FET baseline toxicity. The analysis of the FET dataset revealed that specifically acting and reactive chemicals converged towards the baseline toxicity QSAR with increasing hydrophobicity. The developed FET baseline toxicity QSAR can be used to identify specifically acting or reactive compounds by determination of the toxic ratio and in combination with appropriate endpoints to infer the MOA for chemicals.
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Affiliation(s)
- Nils Klüver
- UFZ - Helmholtz Centre for Environmental Research, Department of Cell Toxicology, Permoserstr. 15, 04318, Leipzig, Germany; UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318, Leipzig, Germany.
| | - Carolina Vogs
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318, Leipzig, Germany
| | - Rolf Altenburger
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318, Leipzig, Germany; RWTH Aachen University, Institute for Environmental Research, Biologie V, Worringerweg 1, 52074, Aachen, Germany
| | - Beate I Escher
- UFZ - Helmholtz Centre for Environmental Research, Department of Cell Toxicology, Permoserstr. 15, 04318, Leipzig, Germany; Eberhard Karls University Tübingen, Center for Applied Geosciences, Environmental Toxicology, Hölderlinstr. 12, 72074, Tübingen, Germany
| | - Stefan Scholz
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318, Leipzig, Germany
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Klüver N, König M, Ortmann J, Massei R, Paschke A, Kühne R, Scholz S. Fish embryo toxicity test: identification of compounds with weak toxicity and analysis of behavioral effects to improve prediction of acute toxicity for neurotoxic compounds. Environ Sci Technol 2015; 49:7002-11. [PMID: 25939044 DOI: 10.1021/acs.est.5b01910] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The fish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, but concerns have been raised for its predictivity given that a few compounds have been shown to exhibit a weak acute toxicity in the fish embryo. In order to better define the applicability domain and improve the predictive capacity of the fish embryo test, we performed a systematic analysis of existing fish embryo and acute fish toxicity data. A correlation analysis of a total of 153 compounds identified 28 compounds with a weaker or no toxicity in the fish embryo test. Eleven of these compounds exhibited a neurotoxic mode of action. We selected a subset of eight compounds with weaker or no embryo toxicity (cyanazine, picloram, aldicarb, azinphos-methyl, dieldrin, diquat dibromide, endosulfan, and esfenvalerate) to study toxicokinetics and a neurotoxic mode of action as potential reasons for the deviating fish embryo toxicity. Published fish embryo LC50 values were confirmed by experimental analysis of zebrafish embryo LC50 according to OECD guideline 236. Except for diquat dibromide, internal concentration analysis did not indicate a potential relation of the low sensitivity of fish embryos to a limited uptake of the compounds. Analysis of locomotor activity of diquat dibromide and the neurotoxic compounds in 98 hpf embryos (exposed for 96 h) indicated a specific effect on behavior (embryonic movement) for the neurotoxic compounds. The EC50s of behavior for neurotoxic compounds were close to the acute fish toxicity LC50. Our data provided the first evidence that the applicability domain of the fish embryo test (LC50s determination) may exclude neurotoxic compounds. However, neurotoxic compounds could be identified by changes in embryonic locomotion. Although a quantitative prediction of acute fish toxicity LC50 using behavioral assays in fish embryos may not yet be possible, the identification of neurotoxicity could trigger the conduction of a conventional fish acute toxicity test or application of assessment factors while considering the very good fish embryo-acute fish toxicity correlation for other compounds.
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Affiliation(s)
- Nils Klüver
- †Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Maria König
- †Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Julia Ortmann
- †Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Riccardo Massei
- †Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Albrecht Paschke
- ‡Department of Ecological Chemistry, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Ralph Kühne
- ‡Department of Ecological Chemistry, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Stefan Scholz
- †Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
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Scholz S, Ortmann J, Klüver N, Léonard M. Extensive review of fish embryo acute toxicities for the prediction of GHS acute systemic toxicity categories. Regul Toxicol Pharmacol 2014; 69:572-9. [PMID: 24929227 DOI: 10.1016/j.yrtph.2014.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 04/14/2014] [Accepted: 06/02/2014] [Indexed: 10/25/2022]
Abstract
Distribution and marketing of chemicals require appropriate labelling of health, physical and environmental hazards according to the United Nations global harmonisation system (GHS). Labelling for (human) acute toxicity categories is based on experimental findings usually obtained by oral, dermal or inhalative exposure of rodents. There is a strong societal demand for replacing animal experiments conducted for safety assessment of chemicals. Fish embryos are considered as alternative to animal testing and are proposed as predictive model both for environmental and human health effects. Therefore, we tested whether LC50s of the fish embryo acute toxicity test would allow effectively predicting of acute mammalian toxicity categories. A database of published fish embryo LC50 containing 641 compounds was established. For these compounds corresponding rat oral LD50 were identified resulting in 364 compounds for which both fish embryo LC50 and rat LD50 was available. Only a weak correlation of fish embryo LC50 and rat oral LD50 was obtained. Fish embryos were also not able to effectively predict GHS oral acute toxicity categories. We concluded that due to fundamental exposure protocol differences (single oral dose versus water-borne exposure) a reverse dosimetry approach is needed to explore the predictive capacity of fish embryos.
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Affiliation(s)
- Stefan Scholz
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Julia Ortmann
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany
| | - Nils Klüver
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany
| | - Marc Léonard
- L'ORÉAL Advanced Research, Environmental Research Department, 1 avenue Eugène Schueller, 93601 Aulnay sous Bois, France
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Klüver N, Ortmann J, Paschke H, Renner P, Ritter AP, Scholz S. Transient overexpression of adh8a increases allyl alcohol toxicity in zebrafish embryos. PLoS One 2014; 9:e90619. [PMID: 24594943 PMCID: PMC3940891 DOI: 10.1371/journal.pone.0090619] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 02/03/2014] [Indexed: 11/28/2022] Open
Abstract
Fish embryos are widely used as an alternative model to study toxicity in vertebrates. Due to their complexity, embryos are believed to more resemble an adult organism than in vitro cellular models. However, concerns have been raised with respect to the embryo's metabolic capacity. We recently identified allyl alcohol, an industrial chemical, to be several orders of magnitude less toxic to zebrafish embryo than to adult zebrafish (embryo LC50 = 478 mg/L vs. fish LC50 = 0.28 mg/L). Reports on mammals have indicated that allyl alcohol requires activation by alcohol dehydrogenases (Adh) to form the highly reactive and toxic metabolite acrolein, which shows similar toxicity in zebrafish embryos and adults. To identify if a limited metabolic capacity of embryos indeed can explain the low allyl alcohol sensitivity of zebrafish embryos, we compared the mRNA expression levels of Adh isoenzymes (adh5, adh8a, adh8b and adhfe1) during embryo development to that in adult fish. The greatest difference between embryo and adult fish was found for adh8a and adh8b expression. Therefore, we hypothesized that these genes might be required for allyl alcohol activation. Microinjection of adh8a, but not adh8b mRNA led to a significant increase of allyl alcohol toxicity in embryos similar to levels reported for adults (LC50 = 0.42 mg/L in adh8a mRNA-injected embryos). Furthermore, GC/MS analysis of adh8a-injected embryos indicated a significant decline of internal allyl alcohol concentrations from 0.23-58 ng/embryo to levels below the limit of detection (< 4.6 µg/L). Injection of neither adh8b nor gfp mRNA had an impact on internal allyl alcohol levels supporting that the increased allyl alcohol toxicity was mediated by an increase in its metabolization. These results underline the necessity to critically consider metabolic activation in the zebrafish embryo. As demonstrated here, mRNA injection is one useful approach to study the role of candidate enzymes involved in metabolization.
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Affiliation(s)
- Nils Klüver
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Julia Ortmann
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Heidrun Paschke
- Department of Analytical Chemistry, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Patrick Renner
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Axel P. Ritter
- Department of Analytical Chemistry, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
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Scholz S, Sela E, Blaha L, Braunbeck T, Galay-Burgos M, García-Franco M, Guinea J, Klüver N, Schirmer K, Tanneberger K, Tobor-Kapłon M, Witters H, Belanger S, Benfenati E, Creton S, Cronin MT, Eggen RI, Embry M, Ekman D, Gourmelon A, Halder M, Hardy B, Hartung T, Hubesch B, Jungmann D, Lampi MA, Lee L, Léonard M, Küster E, Lillicrap A, Luckenbach T, Murk AJ, Navas JM, Peijnenburg W, Repetto G, Salinas E, Schüürmann G, Spielmann H, Tollefsen KE, Walter-Rohde S, Whale G, Wheeler JR, Winter MJ. A European perspective on alternatives to animal testing for environmental hazard identification and risk assessment. Regul Toxicol Pharmacol 2013; 67:506-30. [DOI: 10.1016/j.yrtph.2013.10.003] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/02/2013] [Accepted: 10/16/2013] [Indexed: 12/20/2022]
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Fischer S, Klüver N, Burkhardt-Medicke K, Pietsch M, Schmidt AM, Wellner P, Schirmer K, Luckenbach T. Abcb4 acts as multixenobiotic transporter and active barrier against chemical uptake in zebrafish (Danio rerio) embryos. BMC Biol 2013; 11:69. [PMID: 23773777 PMCID: PMC3765700 DOI: 10.1186/1741-7007-11-69] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 06/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In mammals, ABCB1 constitutes a cellular "first line of defense" against a wide array of chemicals and drugs conferring cellular multidrug or multixenobiotic resistance (MDR/MXR). We tested the hypothesis that an ABCB1 ortholog serves as protection for the sensitive developmental processes in zebrafish embryos against adverse compounds dissolved in the water. RESULTS Indication for ABCB1-type efflux counteracting the accumulation of chemicals in zebrafish embryos comes from experiments with fluorescent and toxic transporter substrates and inhibitors. With inhibitors present, levels of fluorescent dyes in embryo tissue and sensitivity of embryos to toxic substrates were generally elevated. We verified two predicted sequences from zebrafish, previously annotated as abcb1, by cloning; our synteny analyses, however, identified them as abcb4 and abcb5, respectively. The abcb1 gene is absent in the zebrafish genome and we explored whether instead Abcb4 and/or Abcb5 show toxicant defense properties. Quantitative real-time polymerase chain reaction (qPCR) analyses showed the presence of transcripts of both genes throughout the first 48 hours of zebrafish development. Similar to transporter inhibitors, morpholino knock-down of Abcb4 increased accumulation of fluorescent substrates in embryo tissue and sensitivity of embryos toward toxic compounds. In contrast, morpholino knock-down of Abcb5 did not exert this effect. ATPase assays with recombinant protein obtained with the baculovirus expression system confirmed that dye and toxic compounds act as substrates of zebrafish Abcb4 and inhibitors block its function. The compounds tested comprised model substrates of human ABCB1, namely the fluorescent dyes rhodamine B and calcein-am and the toxic compounds vinblastine, vincristine and doxorubicin; cyclosporin A, PSC833, MK571 and verapamil were applied as inhibitors. Additionally, tests were performed with ecotoxicologically relevant compounds: phenanthrene (a polycyclic aromatic hydrocarbon) and galaxolide and tonalide (two polycyclic musks). CONCLUSIONS We show that zebrafish Abcb4 is a cellular toxicant transporter and provides protection of embryos against toxic chemicals dissolved in the water. Zebrafish Abcb4 thus is functionally similar to mammalian ABCB1, but differs from mammalian ABCB4, which is not involved in cellular resistance to chemicals but specifically transports phospholipids in the liver. Our data have important implications: Abcb4 could affect bioavailability - and thus toxicologic and pharmacologic potency - of chemicals to zebrafish embryos and inhibition of Abcb4 therefore causes chemosensitization, that is, enhanced sensitivity of embryos to toxicants. These aspects should be considered in (eco)toxicologic and pharmacologic chemical screens with the zebrafish embryo, a major vertebrate model.
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Affiliation(s)
- Stephan Fischer
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research, 04318 Leipzig, Germany.
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Scholz S, Büttner A, Klüver N, Ortmann J. Prediction of human toxicity with the zebrafish embryo model. Reprod Toxicol 2012. [DOI: 10.1016/j.reprotox.2012.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Klüver N, Yang L, Busch W, Scheffler K, Renner P, Strähle U, Scholz S. Transcriptional response of zebrafish embryos exposed to neurotoxic compounds reveals a muscle activity dependent hspb11 expression. PLoS One 2011; 6:e29063. [PMID: 22205996 PMCID: PMC3242778 DOI: 10.1371/journal.pone.0029063] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 11/20/2011] [Indexed: 01/13/2023] Open
Abstract
Acetylcholinesterase (AChE) inhibitors are widely used as pesticides and drugs. Their primary effect is the overstimulation of cholinergic receptors which results in an improper muscular function. During vertebrate embryonic development nerve activity and intracellular downstream events are critical for the regulation of muscle fiber formation. Whether AChE inhibitors and related neurotoxic compounds also provoke specific changes in gene transcription patterns during vertebrate development that allow them to establish a mechanistic link useful for identification of developmental toxicity pathways has, however, yet not been investigated. Therefore we examined the transcriptomic response of a known AChE inhibitor, the organophosphate azinphos-methyl (APM), in zebrafish embryos and compared the response with two non-AChE inhibiting unspecific control compounds, 1,4-dimethoxybenzene (DMB) and 2,4-dinitrophenol (DNP). A highly specific cluster of APM induced gene transcripts was identified and a subset of strongly regulated genes was analyzed in more detail. The small heat shock protein hspb11 was found to be the most sensitive induced gene in response to AChE inhibitors. Comparison of expression in wildtype, ache and sop(fixe) mutant embryos revealed that hspb11 expression was dependent on the nicotinic acetylcholine receptor (nAChR) activity. Furthermore, modulators of intracellular calcium levels within the whole embryo led to a transcriptional up-regulation of hspb11 which suggests that elevated intracellular calcium levels may regulate the expression of this gene. During early zebrafish development, hspb11 was specifically expressed in muscle pioneer cells and Hspb11 morpholino-knockdown resulted in effects on slow muscle myosin organization. Our findings imply that a comparative toxicogenomic approach and functional analysis can lead to the identification of molecular mechanisms and specific marker genes for potential neurotoxic compounds.
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Affiliation(s)
- Nils Klüver
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany.
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Klüver N, Scheffler K, Renner P, Scholz S. Toxicogenomic response of azinphos-methyl treated zebrafish embryos and implication for the development of predictive models for chronic (fish) toxicity. Toxicol Lett 2009. [DOI: 10.1016/j.toxlet.2009.06.284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Scholz S, Klüver N. Effects of Endocrine Disrupters on Sexual, Gonadal Development in Fish. Sex Dev 2009; 3:136-51. [DOI: 10.1159/000223078] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 11/12/2008] [Indexed: 11/19/2022] Open
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Klüver N, Herpin A, Braasch I, Driessle J, Schartl M. Regulatory back-up circuit of medaka Wt1 co-orthologs ensures PGC maintenance. Dev Biol 2008; 325:179-88. [PMID: 18992736 DOI: 10.1016/j.ydbio.2008.10.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 09/23/2008] [Accepted: 10/12/2008] [Indexed: 11/16/2022]
Abstract
In mammals, the Wilms' tumor suppressor gene, Wt1, encodes a transcription factor critical for development of the urogenital system. In teleost fish, however, two wt1 genes have been identified. In medaka wt1a is expressed in the lateral plate mesoderm during early embryogenesis. Later in development, wt1a is additionally expressed in the somatic cells of the gonadal primordium. We show here for the first time that in teleosts wt1 gene expression is observed during gonad development. Wt1b is expressed later during embryogenesis and is not expressed in the gonadal primordium. Analysis of morpholino knockdown experiments revealed functions of wt1 genes in pronephros development. Unexpectedly, by down-regulating Wt1a protein we observed wt1b expression during embryogenesis in the wildtype wt1a expression domains including somatic cells of the gonadal primordium. Interestingly, neither wt1a nor wt1b morphants showed effects on the gonad development, whereas the double knockdown of wt1a and wt1b displayed strong influences on the number of primordial germ cell (PGC) during gonad development. Our results indicate that medaka wt1 co-orthologs show genetic redundancy in PGC maintenance or survival through responsive backup circuits. This provides first evidence for a conditional co-regulation of these genes within a transcriptional network.
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Affiliation(s)
- Nils Klüver
- University of Würzburg, Physiological Chemistry I, Biozentrum, Am Hubland, D-97074 Würzburg, Germany
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Pala I, Klüver N, Thorsteinsdóttir S, Schartl M, Coelho MM. Expression pattern of anti-Müllerian hormone (amh) in the hybrid fish complex of Squalius alburnoides. Gene 2008; 410:249-58. [PMID: 18242010 DOI: 10.1016/j.gene.2007.12.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 12/03/2007] [Accepted: 12/12/2007] [Indexed: 11/25/2022]
Abstract
In fish of the Squalius alburnoides complex, hybridisation and polyploidy have affected sex ratios, resulting in strong correlations between sex and genotype. The preponderance of females among triploids and the occurrence of an all male lineage among diploids seem to imply that sex ratio deviations should have a strong genetic basis. Until now, no information has been gathered regarding the molecular basis of sex determination in this intricate hybrid system. Thus, putative regulatory elements of the cascade that potentially are involved in sex determination in S. alburnoides have to be investigated. Being reported to have an important role in teleost sex determination, and more particularly in male gonad development, the anti-Müllerian hormone, amh was a good initial candidate. Here we report the isolation, cloning and characterization of the amh ortholog in S. alburnoides and the ancestral species S. pyrenaicus. In adult S. alburnoides and S. pyrenaicus of both sexes, amh shows a gonad specific expression pattern, restricted to the Sertoli cell lineage in testis and to granulosa cells in ovaries. During development, it plays an early role in male gonad differentiation in S. alburnoides. Overall the observed patterns are similar to what has been reported in other teleost species. This suggests a conserved role of amh and implies that its expression dynamics cannot be directly responsible for the sex ratio deviations reported in S. alburnoides. It is possible that a conjunction of other factors could be contributing for sex ratio imbalance. The present results constitute the starting point in the characterization of the S. alburnoides sex determination cascade, a process that we expect to shed some light on the molecular basis of sex distribution, within the context of hybrid system evolution.
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Affiliation(s)
- I Pala
- Departamento de Biologia Animal, Faculdade de Ciências de Lisboa, Lisbon, Portugal.
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Klüver N, Pfennig F, Pala I, Storch K, Schlieder M, Froschauer A, Gutzeit HO, Schartl M. Differential expression of anti-Müllerian hormone (amh) and anti-Müllerian hormone receptor type II (amhrII) in the teleost medaka. Dev Dyn 2007; 236:271-81. [PMID: 17075875 DOI: 10.1002/dvdy.20997] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In mammals, the anti-Müllerian hormone (Amh) is responsible for the regression of the Müllerian ducts; therefore, Amh is an important factor of male sex differentiation. The amh gene has been cloned in various vertebrates, as well as in several teleost species. To date, all described species show a sexually dimorphic expression of amh during sex differentiation or at least in differentiated juvenile gonads. We have identified the medaka amh ortholog and examined its expression pattern. Medaka amh shows no sexually dimorphic expression pattern. It is expressed in both developing XY male and XX female gonads. In adult testes, amh is expressed in the Sertoli cells and in adult ovaries in granulosa cells surrounding the oocytes, like in mammals. To better understand the function of amh, we cloned the anti-Müllerian hormone receptor type II (amhrII) ortholog and compared its expression pattern with amh, aromatase (cyp19a1), and scp3. During gonad development, amhrII is coexpressed with medaka amh in somatic cells of the gonads and shows no sexually dimorphic expression. Only the expression level of the Amh type II receptor gene was decreased noticeably in adult female gonads. These results suggest that medaka Amh and AmhrII are involved in gonad formation and maintenance in both sexes.
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Affiliation(s)
- Nils Klüver
- University of Würzburg, Department of Physiological Chemistry I, Biozentrum, Würzburg, Germany
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Veith AM, Schäfer M, Klüver N, Schmidt C, Schultheis C, Schartl M, Winkler C, Volff JN. Tissue-Specific Expression ofdmrtGenes in Embryos and Adults of the PlatyfishXiphophorus maculatus. Zebrafish 2006; 3:325-37. [DOI: 10.1089/zeb.2006.3.325] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Anne-Marie Veith
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
| | - Matthias Schäfer
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
| | - Nils Klüver
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
| | - Cornelia Schmidt
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
| | | | - Manfred Schartl
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
| | - Christoph Winkler
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
| | - Jean-Nicolas Volff
- Physiologische Chemie I, Biozentrum, University of Würzburg, Würzburg, Germany
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Klüver N, Kondo M, Herpin A, Mitani H, Schartl M. Divergent expression patterns of Sox9 duplicates in teleosts indicate a lineage specific subfunctionalization. Dev Genes Evol 2005; 215:297-305. [PMID: 15818483 DOI: 10.1007/s00427-005-0477-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Accepted: 02/15/2005] [Indexed: 01/27/2023]
Abstract
Sry-related HMG-box genes are key regulators of several developmental processes. Sox9 encodes a transcription factor required for cartilage formation and testis determination in mammals. In zebrafish (Danio rerio) and stickleback (Gasterosteus aculeatus) two co-orthologs of Sox9 are present. To date, only one Sox9 had been identified in medaka (Oryzias latipes). We have now isolated the second Sox9 gene. Sequence analysis, phylogenetic data, linkage mapping as well as expression pattern all together suggest that the medaka Sox9a and Sox9b are co-orthologs. During embryogenesis, the expression pattern of Sox9a and Sox9b are distinct but overlap considerably in craniofacial cartilage elements. Comparing the zebrafish Sox9a and Sox9b expression patterns with medaka Sox9a and Sox9b expression domains revealed that some are identical but others are clearly different. We conclude that Sox9 regulatory subfunctions were not partitioned before divergence of the teleosts and evolved to lineage-specific expression domains.
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Affiliation(s)
- Nils Klüver
- Department of Physiological Chemistry I, University of Würzburg, 97074 Würzburg, Germany
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