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Serafini MM, Sepehri S, Midali M, Stinckens M, Biesiekierska M, Wolniakowska A, Gatzios A, Rundén-Pran E, Reszka E, Marinovich M, Vanhaecke T, Roszak J, Viviani B, SenGupta T. Recent advances and current challenges of new approach methodologies in developmental and adult neurotoxicity testing. Arch Toxicol 2024; 98:1271-1295. [PMID: 38480536 DOI: 10.1007/s00204-024-03703-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/06/2024] [Indexed: 03/27/2024]
Abstract
Adult neurotoxicity (ANT) and developmental neurotoxicity (DNT) assessments aim to understand the adverse effects and underlying mechanisms of toxicants on the human nervous system. In recent years, there has been an increasing focus on the so-called new approach methodologies (NAMs). The Organization for Economic Co-operation and Development (OECD), together with European and American regulatory agencies, promote the use of validated alternative test systems, but to date, guidelines for regulatory DNT and ANT assessment rely primarily on classical animal testing. Alternative methods include both non-animal approaches and test systems on non-vertebrates (e.g., nematodes) or non-mammals (e.g., fish). Therefore, this review summarizes the recent advances of NAMs focusing on ANT and DNT and highlights the potential and current critical issues for the full implementation of these methods in the future. The status of the DNT in vitro battery (DNT IVB) is also reviewed as a first step of NAMs for the assessment of neurotoxicity in the regulatory context. Critical issues such as (i) the need for test batteries and method integration (from in silico and in vitro to in vivo alternatives, e.g., zebrafish, C. elegans) requiring interdisciplinarity to manage complexity, (ii) interlaboratory transferability, and (iii) the urgent need for method validation are discussed.
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Affiliation(s)
- Melania Maria Serafini
- Department of Pharmacological and Biomolecular Sciences, "Rodolfo Paoletti", Università degli Studi di Milano, Milan, Italy.
| | - Sara Sepehri
- Department of In Vitro Toxicology and Dermato-Cosmetology (IVTD), Vrije Universiteit Brussels, Brussels, Belgium
| | - Miriam Midali
- Department of Pharmacological and Biomolecular Sciences, "Rodolfo Paoletti", Università degli Studi di Milano, Milan, Italy
| | - Marth Stinckens
- Department of In Vitro Toxicology and Dermato-Cosmetology (IVTD), Vrije Universiteit Brussels, Brussels, Belgium
| | - Marta Biesiekierska
- Department of Translational Research, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Anna Wolniakowska
- Department of Translational Research, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Alexandra Gatzios
- Department of In Vitro Toxicology and Dermato-Cosmetology (IVTD), Vrije Universiteit Brussels, Brussels, Belgium
| | - Elise Rundén-Pran
- The Climate and Environmental Research Institute NILU, Kjeller, Norway
| | - Edyta Reszka
- Department of Translational Research, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Marina Marinovich
- Department of Pharmacological and Biomolecular Sciences, "Rodolfo Paoletti", Università degli Studi di Milano, Milan, Italy
- Center of Research on New Approach Methodologies (NAMs) in chemical risk assessment (SAFE-MI), Università degli Studi di Milano, Milan, Italy
| | - Tamara Vanhaecke
- Department of In Vitro Toxicology and Dermato-Cosmetology (IVTD), Vrije Universiteit Brussels, Brussels, Belgium
| | - Joanna Roszak
- Department of Translational Research, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Barbara Viviani
- Department of Pharmacological and Biomolecular Sciences, "Rodolfo Paoletti", Università degli Studi di Milano, Milan, Italy
- Center of Research on New Approach Methodologies (NAMs) in chemical risk assessment (SAFE-MI), Università degli Studi di Milano, Milan, Italy
| | - Tanima SenGupta
- The Climate and Environmental Research Institute NILU, Kjeller, Norway
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2
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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. FRONTIERS IN TOXICOLOGY 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] [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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Oh HN, Yoo D, Park S, Lee S, Kim WK. Assessment of poly(hexamethylenebicyanoguanide-hexamethylenediamine) hydrochloride-induced developmental neurotoxicity via oxidative stress mechanism: Integrative approaches with neuronal cells and zebrafish. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133146. [PMID: 38064952 DOI: 10.1016/j.jhazmat.2023.133146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/22/2023] [Accepted: 11/28/2023] [Indexed: 02/08/2024]
Abstract
Poly(hexamethylenebicyanoguanide-hexamethylenediamine) hydrochloride (PHMB) is a biocide with a broad spectrum of antibacterial activity. Its use as a disinfectant and preservative in consumer products results in human exposure to PHMB. Toxicity studies on PHMB mainly focus on systemic toxicity or skin irritation; however, its effects on developmental neurotoxicity (DNT) and the underlying mechanisms are poorly understood. In this study, the DNT effects of PHMB were evaluated using IMR-32 and SH-SY5Y cell lines and zebrafish. In both cell lines, PHMB concentrations ≥ 10 µM reduced neurite outgrowth, and cytotoxicity was observed at concentrations up to 40 µM. PHMB regulated expression of neurodevelopmental genes and induced reactive oxygen species (ROS) production and mitochondrial dysfunction. Treatment with N-acetylcysteine reversed the toxic effects of PHMB. Toxicity tests on zebrafish embryos showed that PHMB reduced viability and heart rate and caused irregular hatching. PHMB concentrations of 1-4 µM reduced the width of the brain and spinal cord of transgenic zebrafish and attenuated myelination processes. Furthermore, PHMB modulated expression of neurodevelopmental genes in zebrafish and induced ROS accumulation. These results suggested that PHMB exerted DNT effects in vitro and in vivo through a ROS-dependent mechanism, highlighting the risk of PHMB exposure.
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Affiliation(s)
- Ha-Na Oh
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Donggon Yoo
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea; Human and Environmental Toxicology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Seungmin Park
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea; Human and Environmental Toxicology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Sangwoo Lee
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea; Human and Environmental Toxicology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Woo-Keun Kim
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea; Human and Environmental Toxicology, University of Science and Technology, Daejeon 34113, Republic of Korea.
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4
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Zhao H, Xie J, Wu S, Zhao X, Sánchez OF, Min S, Rochet JC, Freeman JL, Yuan C. Elevated parkinsonism pathological markers in dopaminergic neurons with developmental exposure to atrazine. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168307. [PMID: 37949145 PMCID: PMC10843769 DOI: 10.1016/j.scitotenv.2023.168307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023]
Abstract
Atrazine (ATZ) is one of the most used herbicides in the US and a known endocrine disruptor. ATZ is frequently detected in drinking water, especially in Midwestern regions of the United States, exceeding the EPA regulation of maximum contamination level (MCL) of 3 ppb. Epidemiology studies have suggested an association between ATZ exposure and neurodegeneration. Less, however, is known about the neurotoxic mechanism of ATZ, particularly for exposures at a developmental stage. Here, we exposed floor plate progenitors (FPPs) derived from human induced pluripotent stem cells (hiPSCs) to low concentrations of ATZ at 0.3 and 3 ppb for two days followed by differentiation into dopaminergic (DA) neurons in ATZ-free medium. We then examined the morphology, activity, pathological protein aggregation, and transcriptomic changes of differentiated DA neurons. We observed significant decrease in the complexity of neurite network, increase of neuronal activity, and elevated tau- and α-synuclein (aSyn) pathologies after ATZ exposure. The ATZ-induced neuronal changes observed here align with pathological characteristics in Parkinson's disease (PD). Transcriptomic analysis further corroborates our findings; and collectively provides a strong evidence base that low-concentration ATZ exposure during development can elicit increased risk of neurodegeneration.
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Affiliation(s)
- Han Zhao
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, United States of America
| | - Junkai Xie
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, United States of America
| | - Shichen Wu
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, United States of America
| | - Xihui Zhao
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, United States of America
| | - Oscar F Sánchez
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, United States of America
| | - Sehong Min
- Department of Medicinal Chemistry and Molecular Pharmacy, Purdue University, West Lafayette, IN 47907, United States of America
| | - Jean-Christophe Rochet
- Department of Medicinal Chemistry and Molecular Pharmacy, Purdue University, West Lafayette, IN 47907, United States of America; Purdue Institute of Integrated Neuroscience, Purdue University, West Lafayette, IN 47907, United States of America
| | - Jennifer L Freeman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States of America; Purdue Institute of Integrated Neuroscience, Purdue University, West Lafayette, IN 47907, United States of America
| | - Chongli Yuan
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, United States of America; Purdue Institute of Integrated Neuroscience, Purdue University, West Lafayette, IN 47907, United States of America; Purdue Center of Cancer Research, West Lafayette, IN 47907, United States of America.
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5
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Juberg DR, Fox DA, Forcelli PA, Kacew S, Lipscomb JC, Saghir SA, Sherwin CM, Koenig CM, Hays SM, Kirman CR. A perspective on In vitro developmental neurotoxicity test assay results: An expert panel review. Regul Toxicol Pharmacol 2023; 143:105444. [PMID: 37442267 DOI: 10.1016/j.yrtph.2023.105444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/21/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023]
Abstract
For decades, there has been increasing concern about the potential developmental neurotoxicity (DNT) associated with chemicals. Regulatory agencies have historically utilized standardized in vivo testing to evaluate DNT. Owing to considerations including higher-throughput screening for DNT, reduction in animal use, and potential cost efficiencies, the development of alternative new approach methods (NAMs) occurred; specifically, the advent of the DNT in vitro test battery (DNT IVB). SciPinion convened an expert panel to address specific questions related to the interpretation of in vitro DNT test data. The consensus of the expert panel was that the DNT IVB might be used during initial screening, but it is not presently a complete or surrogate approach to determine whether a chemical is a DNT in humans. By itself, the DNT IVB does not have the ability to capture nuances and complexity of the developing nervous system and associated outcomes including behavioral ontogeny, motor activity, sensory function, and learning/memory. Presently, such developmental landmarks cannot be adequately assessed in the DNT IVB or by other NAMs. The expert panel (all who serve as co-authors of this review) recommended that additional data generation and validation is required before the DNT IVB can be considered for application within global regulatory frameworks for decision-making.
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Affiliation(s)
- D R Juberg
- Juberg Toxicology Consulting LLC, Indianapolis, IN, USA
| | - D A Fox
- DAFoxTox Consulting, Austin, TX, USA
| | | | - S Kacew
- University of Ottawa, Ottawa, CA, USA
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Mie A, Rudén C. Non-disclosure of developmental neurotoxicity studies obstructs the safety assessment of pesticides in the European Union. Environ Health 2023; 22:44. [PMID: 37259092 PMCID: PMC10234068 DOI: 10.1186/s12940-023-00994-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/05/2023] [Indexed: 06/02/2023]
Abstract
BACKGROUND In the European Union (EU), the safety assessment of plant protection products relies to a large extent on toxicity studies commissioned by the companies producing them. By law, all performed studies must be included in the dossier submitted to authorities when applying for approval or renewal of the active substance. METHODS For one type of toxicity, i.e. developmental neurotoxicity (DNT), we evaluated if studies submitted to the U.S. Environmental Protection Agency (EPA) had also been disclosed to EU authorities. RESULTS We identified 35 DNT studies submitted to the U.S. EPA and with the corresponding EU dossiers available. Of these, 9 DNT studies (26%) were not disclosed by the pesticide company to EU authorities. For 7 of these studies, we have identified an actual or potential regulatory impact. CONCLUSIONS We conclude that (1) non-disclosure of DNT studies to EU authorities, in spite of clear legal requirements, seems to be a recurring phenomenon, (2) the non-disclosure may introduce a bias in the regulatory risk assessment, and (3) without full access to all performed toxicity studies, there can be no reliable safety evaluation of pesticides by EU authorities. We suggest that EU authorities should cross-check their data sets with their counterparts in other jurisdictions. In addition, applications for pesticide approval should be cross-checked against lists of studies performed at test facilities operating under Good Laboratory Practice (GLP), to ensure that all studies have been submitted to authorities. Furthermore, rules should be amended so that future studies should be commissioned by authorities rather than companies. This ensures the authorities' knowledge of existing studies and prevents the economic interest of the company from influencing the design, performance, reporting and dissemination of studies. The rules or practices should also be revised to ensure that non-disclosure of toxicity studies carries a significant legal risk for pesticide companies.
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Affiliation(s)
- Axel Mie
- Department of Environmental Science, Stockholm University, Stockholm, 10691, Sweden.
- Department of Clinical Science and Education, Karolinska Institutet, Södersjukhuset, Stockholm, 11883, Sweden.
- Centre for Organic Food and Farming (EPOK), Swedish University of Agricultural Sciences (SLU), Ultuna, Uppsala, Sweden.
| | - Christina Rudén
- Department of Environmental Science, Stockholm University, Stockholm, 10691, Sweden
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7
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von Hellfeld R, Gade C, Baumann L, Leist M, Braunbeck T. The sensitivity of the zebrafish embryo coiling assay for the detection of neurotoxicity by compounds with diverse modes of action. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27662-2. [PMID: 37213015 DOI: 10.1007/s11356-023-27662-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 05/11/2023] [Indexed: 05/23/2023]
Abstract
In the aim to determine neurotoxicity, new methods are being validated, including tests and test batteries comprising in vitro and in vivo approaches. Alternative test models such as the zebrafish (Danio rerio) embryo have received increasing attention, with minor modifications of the fish embryo toxicity test (FET; OECD TG 236) as a tool to assess behavioral endpoints related to neurotoxicity during early developmental stages. The spontaneous tail movement assay, also known as coiling assay, assesses the development of random movement into complex behavioral patterns and has proven sensitive to acetylcholine esterase inhibitors at sublethal concentrations. The present study explored the sensitivity of the assay to neurotoxicants with other modes of action (MoAs). Here, five compounds with diverse MoAs were tested at sublethal concentrations: acrylamide, carbaryl, hexachlorophene, ibuprofen, and rotenone. While carbaryl, hexachlorophene, and rotenone consistently induced severe behavioral alterations by ~ 30 h post fertilization (hpf), acrylamide and ibuprofen expressed time- and/or concentration-dependent effects. At 37-38 hpf, additional observations revealed behavioral changes during dark phases with a strict concentration-dependency. The study documented the applicability of the coiling assay to MoA-dependent behavioral alterations at sublethal concentrations, underlining its potential as a component of a neurotoxicity test battery.
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Affiliation(s)
- Rebecca von Hellfeld
- School of Biological Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UK, UK.
- National Decommissioning Centre, Main Street, Ellon, AB41 6AA, UK.
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Christoph Gade
- School of Biological Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UK, UK
- National Decommissioning Centre, Main Street, Ellon, AB41 6AA, UK
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
- Faculty of Science, Environmental Health & Toxicology, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amersterdam, Netherlands
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitätsstraße 10, 78464, Constance, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
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8
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Chen D, Huang H, Huang Y, Yang W, Shan W, Hao G, Wu J, Song B. Toxicity Tests for Chemical Pesticide Registration: Requirement Differences among the United States, the European Union, Japan, and China? JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:7192-7200. [PMID: 37144888 DOI: 10.1021/acs.jafc.3c00410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Pesticide registration is a scientific, legal, and administrative process that checks if a pesticide is safe and effective for its intended use before it can be used. The toxicity test is a key part of pesticide registration, which includes human health and ecological effect testing. Different countries adopt their own toxicity test criteria for pesticide registration guidelines. However, these differences, which may help accelerate the progress of pesticide registration and reduce the number of animals used, are yet to be explored and compared. Herein, we outlined the details and compared the differences between the toxicity tests in the United States, the European Union, Japan, and China. Some differences lie in the types and waiver policy, while others are in new approach methodologies (NAMs). On the basis of these differences, there is great potential for the optimization of NAMs during the toxicity tests. It is expected that this perspective can contribute to developing and adopting NAMs.
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Affiliation(s)
- Dongyu Chen
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Hui Huang
- Department of Planting Management, Ministry of Agriculture and Rural Affairs, Beijing 100125, People's Republic of China
| | - Yuanqin Huang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Weicheng Yang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Weili Shan
- Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Affairs, Beijing 100125, People's Republic of China
| | - Gefei Hao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Jian Wu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Baoan Song
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
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9
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Calisir M, Yilmaz O, Kolatan HE, Sezgin AK. EFFECTS OF LITTER SIZE AND CAGING ON PHYSICAL AND MENTAL DEVELOPMENT IN RATS. Physiol Behav 2023; 267:114200. [PMID: 37075964 DOI: 10.1016/j.physbeh.2023.114200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/21/2023] [Accepted: 04/14/2023] [Indexed: 04/21/2023]
Abstract
As a multidisciplinary field, laboratory animal science promotes or accelerates the emergence of innovative ideas and products. As research has increased, so has the demand for laboratory animals with reliable, standardized characteristics. Thus, the breeding, reproduction, and welfare of laboratory animals are now animals reliable and more. The aim of this study to investigate whether different litter sizes of mothers and different husbandry methods affect the physical and mental development of pups. 30 adults female Wistar Hanover albino rats weighing 200-250 g were used for the study. The weight of the pups was measured once a week from birth until the end of the study, and their physical development was observed. After the pups were weaned, they were randomly divided into cages by sex. The 45 male and 45 female pups were housed in groups of three, five, and seven per cage. When the pups were 12 weeks old, open field test, elevated plus-maze test and Morris water maze behavioral tests were performed every other day, and then plasma corticosterone levels were measured. When the male and female pups in the groups were 14 weeks old, six females were taken from each housing group and mated, and the conception rates and maternal behavior of the pups were observed. During lactation, physical developmental parameters and the body weight of the rats were affected by litter size. Among the post-weaning housing groups, cage density was found to affect weight gain and body weight between groups. It was found that only the sex factor caused significant differences in the behavior of the animals. Females housed with seven rats per cage had higher corticosteroid levels than other females. As a result, it was observed that cages with seven female rats were more physically and psychologically affected than those with three and five rats.
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Affiliation(s)
- Meryem Calisir
- Department of Laboratory Animal Science, Institute of Health Sciences, Dokuz Eylul University, İzmir, Turkey.
| | - Osman Yilmaz
- Department of Laboratory Animal Science, Institute of Health Sciences, Dokuz Eylul University, İzmir, Turkey
| | - Hatice Efsun Kolatan
- Department of Laboratory Animal Science, Institute of Health Sciences, Dokuz Eylul University, İzmir, Turkey
| | - Ayşe Kocak Sezgin
- Department of Molecular Medicine, Institute of Health Sciences, Dokuz Eylul University, İzmir, Turkey
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10
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Blum J, Masjosthusmann S, Bartmann K, Bendt F, Dolde X, Dönmez A, Förster N, Holzer AK, Hübenthal U, Keßel HE, Kilic S, Klose J, Pahl M, Stürzl LC, Mangas I, Terron A, Crofton KM, Scholze M, Mosig A, Leist M, Fritsche E. Establishment of a human cell-based in vitro battery to assess developmental neurotoxicity hazard of chemicals. CHEMOSPHERE 2023; 311:137035. [PMID: 36328314 DOI: 10.1016/j.chemosphere.2022.137035] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Developmental neurotoxicity (DNT) is a major safety concern for all chemicals of the human exposome. However, DNT data from animal studies are available for only a small percentage of manufactured compounds. Test methods with a higher throughput than current regulatory guideline methods, and with improved human relevance are urgently needed. We therefore explored the feasibility of DNT hazard assessment based on new approach methods (NAMs). An in vitro battery (IVB) was assembled from ten individual NAMs that had been developed during the past years to probe effects of chemicals on various fundamental neurodevelopmental processes. All assays used human neural cells at different developmental stages. This allowed us to assess disturbances of: (i) proliferation of neural progenitor cells (NPC); (ii) migration of neural crest cells, radial glia cells, neurons and oligodendrocytes; (iii) differentiation of NPC into neurons and oligodendrocytes; and (iv) neurite outgrowth of peripheral and central neurons. In parallel, cytotoxicity measures were obtained. The feasibility of concentration-dependent screening and of a reliable biostatistical processing of the complex multi-dimensional data was explored with a set of 120 test compounds, containing subsets of pre-defined positive and negative DNT compounds. The battery provided alerts (hit or borderline) for 24 of 28 known toxicants (82% sensitivity), and for none of the 17 negative controls. Based on the results from this screen project, strategies were developed on how IVB data may be used in the context of risk assessment scenarios employing integrated approaches for testing and assessment (IATA).
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Affiliation(s)
- Jonathan Blum
- In Vitro Toxicology and Biomedicine, Dept Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany.
| | - Stefan Masjosthusmann
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Kristina Bartmann
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Farina Bendt
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Xenia Dolde
- In Vitro Toxicology and Biomedicine, Dept Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany
| | - Arif Dönmez
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Nils Förster
- Bioinformatics Group, Ruhr University Bochum, 44801, Bochum, Germany
| | - Anna-Katharina Holzer
- In Vitro Toxicology and Biomedicine, Dept Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany
| | - Ulrike Hübenthal
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Hagen Eike Keßel
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Sadiye Kilic
- In Vitro Toxicology and Biomedicine, Dept Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany
| | - Jördis Klose
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Melanie Pahl
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Lynn-Christin Stürzl
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany
| | - Iris Mangas
- European Food Safety Authority, PREV Unit, 43126, Parma, Italy
| | - Andrea Terron
- European Food Safety Authority, PREV Unit, 43126, Parma, Italy
| | | | - Martin Scholze
- Institute of Environment Health and Societies, Brunel University London, UK
| | - Axel Mosig
- Bioinformatics Group, Ruhr University Bochum, 44801, Bochum, Germany
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Dept Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany.
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, 40225, Düsseldorf, Germany; Medical Faculty, Heinrich-Heine-University, 40225, Düsseldorf, Germany.
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Jahan S, Nesa M, Hossain ME, Rajbangshi JC, Hossain MS. In vivo and in silico evaluation of analgesic and hypoglycemic activities of Amaranthus blitum L. SOUTH AFRICAN JOURNAL OF BOTANY 2022; 150:565-575. [DOI: 10.1016/j.sajb.2022.07.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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12
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Marty MS, Sauer UG, Charlton A, Ghaffari R, Guignard D, Hallmark N, Hannas BR, Jacobi S, Marxfeld HA, Melching-Kollmuss S, Sheets LP, Urbisch D, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny-part III: how is substance-mediated thyroid hormone imbalance in pregnant/lactating rats or their progeny related to neurodevelopmental effects? Crit Rev Toxicol 2022; 52:546-617. [PMID: 36519295 DOI: 10.1080/10408444.2022.2130166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review investigated which patterns of thyroid- and brain-related effects are seen in rats upon gestational/lactational exposure to 14 substances causing thyroid hormone imbalance by four different modes-of-action (inhibition of thyroid peroxidase, sodium-iodide symporter and deiodinase activities, enhancement of thyroid hormone clearance) or to dietary iodine deficiency. Brain-related parameters included motor activity, cognitive function, acoustic startle response, hearing function, periventricular heterotopia, electrophysiology and brain gene expression. Specific modes-of-action were not related to specific patterns of brain-related effects. Based upon the rat data reviewed, maternal serum thyroid hormone levels do not show a causal relationship with statistically significant neurodevelopmental effects. Offspring serum thyroxine together with offspring serum triiodothyronine and thyroid stimulating hormone appear relevant to predict the likelihood for neurodevelopmental effects. Based upon the collated database, thresholds of ≥60%/≥50% offspring serum thyroxine reduction and ≥20% and statistically significant offspring serum triiodothyronine reduction indicate an increased likelihood for statistically significant neurodevelopmental effects; accuracies: 83% and 67% when excluding electrophysiology (and gene expression). Measurements of brain thyroid hormone levels are likely relevant, too. The extent of substance-mediated thyroid hormone imbalance appears more important than substance mode-of-action to predict neurodevelopmental impairment in rats. Pertinent research needs were identified, e.g. to determine whether the phenomenological offspring thyroid hormone thresholds are relevant for regulatory toxicity testing. The insight from this review shall be used to suggest a tiered testing strategy to determine whether gestational/lactational substance exposure may elicit thyroid hormone imbalance and potentially also neurodevelopmental effects.
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Affiliation(s)
| | - Ursula G Sauer
- Scientific Consultancy-Animal Welfare, Neubiberg, Germany
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13
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Cabrita A, Medeiros AM, Pereira T, Rodrigues AS, Kranendonk M, Mendes CS. Motor dysfunction in Drosophila melanogaster as a biomarker for developmental neurotoxicity. iScience 2022; 25:104541. [PMID: 35769875 PMCID: PMC9234254 DOI: 10.1016/j.isci.2022.104541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 10/30/2021] [Accepted: 06/02/2022] [Indexed: 11/18/2022] Open
Abstract
Adequate alternatives to conventional animal testing are needed to study developmental neurotoxicity (DNT). Here, we used kinematic analysis to assess DNT of known (toluene (TOL) and chlorpyrifos (CPS)) and putative (β-N-methylamino-L-alanine (BMAA)) neurotoxic compounds. Drosophila melanogaster was exposed to these compounds during development and evaluated for survival and adult kinematic parameters using the FlyWalker system, a kinematics evaluation method. At concentrations that do not induce general toxicity, the solvent DMSO had a significant effect on kinematic parameters. Moreover, while TOL did not significantly induce lethality or kinematic dysfunction, CPS not only induced developmental lethality but also significantly impaired coordination in comparison to DMSO. Interestingly, BMAA, which was not lethal during development, induced motor decay in young adult animals, phenotypically resembling aged flies, an effect later attenuated upon aging. Furthermore, BMAA induced abnormal development of leg motor neuron projections. Our results suggest that our kinematic approach can assess potential DNT of chemical compounds. Alternatives to mammalian testing are needed to detect developmental neurotoxicity The pesticide chlorpyrifos causes partial lethality and motor dysfunction Non-lethal levels of BMAA induce motor dysfunction in a dose-dependent manner Kinematic profiling of adult Drosophila can identify developmental neurotoxicity
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Affiliation(s)
- Ana Cabrita
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Alexandra M. Medeiros
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Telmo Pereira
- NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - António Sebastião Rodrigues
- ToxOmics, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Michel Kranendonk
- ToxOmics, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
- Corresponding author
| | - César S. Mendes
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
- Corresponding author
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14
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Coccini T, Spinillo A, Roccio M, Lenta E, Valsecchi C, De Simone U. Human Umbilical Cord Mesenchymal Stem Cell-Based in vitro Model for Neurotoxicity Testing. Curr Protoc 2022; 2:e423. [PMID: 35471597 DOI: 10.1002/cpz1.423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neurotoxicity (NT) testing for regulatory purposes is based on in vivo animal testing. There is general consensus, however, about the need for the development of alternative methodologies to allow researchers to more rapidly and cost effectively screen large numbers of chemicals for their potential to cause NT, or to investigate their mode of action. In vitro assays are considered an important source of information for making regulatory decisions, and human cell-based systems are recommended as one of the most relevant models in toxicity testing, to reduce uncertainty in the extrapolation of results from animal-based models. Human neuronal models range from various neuroblastoma cell lines to stem cell-derived systems, including those derived from mesenchymal stem/stromal cells (hMSC). hMSCs exhibit numerous advantages, including the fact that they can be obtained in high yield from healthy human adult tissues, can be cultured with a minimal laboratory setup and without genetic manipulations, are able of continuous and repeated self-renewal, are nontumorigenic, and can form large populations of stably differentiated cells representative of different tissues, including neuronal cells. hMSCs derived from human umbilical cord (hUC) in particular possess several prominent advantages, including a painless, non-invasive, and ethically acceptable collection procedure, simple and convenient preparation, and high proliferation capacity. In addition, hMSCs can be efficiently differentiated into neuron-like cells (hNLCs), which can then be used for the assessment of neuronal toxicity of potential neurotoxic compounds in humans. Here, we describe a step-by-step procedure to use hMSCs from the umbilical cord for in vitro neurotoxicity testing. First, we describe how to isolate, amplify, and store hMSCs derived from the umbilical cord. We then outline the steps to transdifferentiate these cells into hNLCs, and then use the hNLCs for neurotoxicity testing by employing multiple common cytotoxicity assays after treatment with test compounds. The approach follows the most updated guidance on using human cell-based systems. These protocols will allow investigators to implement an alternative system for obtaining primary NLCs of human origin, and support advancement in neurotoxicity research. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Isolation and maintenance of human mesenchymal stem/stromal cells (hMSCs) obtained from the umbilical cord lining membrane Basic Protocol 2: Transdifferentiation of hMSCs into neuron-like cells (hNLCs) and basic neurotoxicity assessment.
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Affiliation(s)
- Teresa Coccini
- Laboratory of Clinical and Experimental Toxicology, and Pavia Poison Centre-National Toxicology Information Centre, Toxicology Unit, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
| | - Arsenio Spinillo
- Department of Obstetrics and Gynecology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy
| | - Marianna Roccio
- Department of Obstetrics and Gynecology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy
| | - Elisa Lenta
- Immunology and Transplantation Laboratory, Pediatric Hematology Oncology Unit, Cell Factory, Department of Maternal and Children's Health, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Chiara Valsecchi
- Immunology and Transplantation Laboratory, Pediatric Hematology Oncology Unit, Cell Factory, Department of Maternal and Children's Health, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Uliana De Simone
- Laboratory of Clinical and Experimental Toxicology, and Pavia Poison Centre-National Toxicology Information Centre, Toxicology Unit, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
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15
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Koch K, Bartmann K, Hartmann J, Kapr J, Klose J, Kuchovská E, Pahl M, Schlüppmann K, Zühr E, Fritsche E. Scientific Validation of Human Neurosphere Assays for Developmental Neurotoxicity Evaluation. FRONTIERS IN TOXICOLOGY 2022; 4:816370. [PMID: 35295221 PMCID: PMC8915868 DOI: 10.3389/ftox.2022.816370] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/21/2022] [Indexed: 01/06/2023] Open
Abstract
There is a call for a paradigm shift in developmental neurotoxicity (DNT) evaluation, which demands the implementation of faster, more cost-efficient, and human-relevant test systems than current in vivo guideline studies. Under the umbrella of the Organisation for Economic Co-operation and Development (OECD), a guidance document is currently being prepared that instructs on the regulatory use of a DNT in vitro battery (DNT IVB) for fit-for-purpose applications. One crucial issue for OECD application of methods is validation, which for new approach methods (NAMs) requires novel approaches. Here, mechanistic information previously identified in vivo, as well as reported neurodevelopmental adversities in response to disturbances on the cellular and tissue level, are of central importance. In this study, we scientifically validate the Neurosphere Assay, which is based on human primary neural progenitor cells (hNPCs) and an integral part of the DNT IVB. It assesses neurodevelopmental key events (KEs) like NPC proliferation (NPC1ab), radial glia cell migration (NPC2a), neuronal differentiation (NPC3), neurite outgrowth (NPC4), oligodendrocyte differentiation (NPC5), and thyroid hormone-dependent oligodendrocyte maturation (NPC6). In addition, we extend our work from the hNPCs to human induced pluripotent stem cell-derived NPCs (hiNPCs) for the NPC proliferation (iNPC1ab) and radial glia assays (iNPC2a). The validation process we report for the endpoints studied with the Neurosphere Assays is based on 1) describing the relevance of the respective endpoints for brain development, 2) the confirmation of the cell type-specific morphologies observed in vitro, 3) expressions of cell type-specific markers consistent with those morphologies, 4) appropriate anticipated responses to physiological pertinent signaling stimuli and 5) alterations in specific in vitro endpoints upon challenges with confirmed DNT compounds. With these strong mechanistic underpinnings, we posit that the Neurosphere Assay as an integral part of the DNT in vitro screening battery is well poised for DNT evaluation for regulatory purposes.
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Affiliation(s)
- Katharina Koch
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Kristina Bartmann
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Julia Hartmann
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Julia Kapr
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Jördis Klose
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Eliška Kuchovská
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Melanie Pahl
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Kevin Schlüppmann
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Etta Zühr
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Ellen Fritsche
- IUF—Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
- Medical Faculty, Heinrich-Heine-University, Duesseldorf, Germany
- *Correspondence: Ellen Fritsche,
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Bolon B, Dostal LA, Garman RH. Neuropathology Evaluation in Juvenile Toxicity Studies in Rodents: Comparison of Developmental Neurotoxicity Studies for Chemicals With Juvenile Animal Studies for Pediatric Pharmaceuticals. Toxicol Pathol 2021; 49:1405-1415. [PMID: 34620000 DOI: 10.1177/01926233211045321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The developmental neuropathology examination in juvenile toxicity studies depends on the nature of the product candidate, its intended use, and the exposure scenario (eg, dose, duration, and route). Expectations for sampling, processing, and evaluating neural tissues differ for developmental neurotoxicity studies (DNTS) for chemicals and juvenile animal studies (JAS) for pediatric pharmaceuticals. Juvenile toxicity studies typically include macroscopic observations, brain weights, and light microscopic evaluation of routine hematoxylin and eosin (H&E)-stained sections from major neural tissues (brain, spinal cord, and sciatic nerve) as neuropathology endpoints. The DNTS is a focused evaluation of the nervous system, so the study design incorporates perfusion fixation, plastic embedding of at least one nerve, quantitative analysis of selected brain regions, and sometimes special neurohistological stains. In contrast, the JAS examines multiple systems, so neural tissues undergo conventional tissue processing (eg, immersion fixation, paraffin embedding, H&E staining only). An "expanded neurohistopathology" (or "expanded neuropathology") approach may be performed for JAS if warranted, typically by light microscopic evaluation of more neural tissues (usually additional sections of brain, ganglia, and/or more nerves) or/and special neurohistological stains, to investigate specific questions (eg, a more detailed exploration of a potential neuroactive effect) or to fulfill regulatory requests.
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Vorhees CV, Williams MT. Issues in the design, analysis, and application of rodent developmental neurotoxicology studies. Neurotoxicol Teratol 2021; 87:107018. [PMID: 34256163 PMCID: PMC8440477 DOI: 10.1016/j.ntt.2021.107018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/02/2021] [Accepted: 07/09/2021] [Indexed: 12/16/2022]
Abstract
Developmental neurotoxicity (DNT) studies could benefit from revisions to study design, data analysis, and some behavioral test methods to enhance reproducibility. The Environmental Protection Agency (EPA) reviewed 69 studies submitted to the Office of Pesticide Programs. Two of the behavioral tests identified the lowest observable adverse effect level (LOAEL) 20 and 13 times, respectively, while the other two tests identified the LOAEL only 3 and 4 times, respectively. The EPA review showed that the functional observational battery (FOB) was least effective at detecting the LOAEL, whereas tests of learning and memory (L&M) had methodological shortcomings. Human neurodevelopmental toxicity studies over the past 30 years show that most of the adverse effects are on higher cognitive functions such as L&M. The results of human studies together with structure-function relationships from neuroscience, suggest that tests of working memory, spatial navigation/memory, and egocentric navigation/memory should be added to guideline studies. Collectively, the above suggest that EPA and EU DNT studies would better reflect human findings and be more relevant to children by aligning L&M tests to the same domains that are affected in children, removing less useful methods (FOB), and using newer statistical models to better account for random factors of litter and litter × sex. Common issues in study design and data analyses are discussed: sample size, random group assignment, blinding, elimination of subjective rating methods, avoiding confirmation bias, more complete reporting of species, housing, test protocols, age, test order, and litter effects. Litter in DNT studies should at least be included as a random factor in ANOVA models and may benefit from inclusion of litter × sex as random factors.
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Affiliation(s)
- Charles V Vorhees
- Department of Pediatrics, College of Medicine, University of Cincinnati and Division of Pediatric Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States of America.
| | - Michael T Williams
- Department of Pediatrics, College of Medicine, University of Cincinnati and Division of Pediatric Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States of America
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Chesnut M, Paschoud H, Repond C, Smirnova L, Hartung T, Zurich MG, Hogberg HT, Pamies D. Human IPSC-Derived Model to Study Myelin Disruption. Int J Mol Sci 2021; 22:ijms22179473. [PMID: 34502381 PMCID: PMC8430601 DOI: 10.3390/ijms22179473] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 12/15/2022] Open
Abstract
Myelin is of vital importance to the central nervous system and its disruption is related to a large number of both neurodevelopmental and neurodegenerative diseases. The differences observed between human and rodent oligodendrocytes make animals inadequate for modeling these diseases. Although developing human in vitro models for oligodendrocytes and myelinated axons has been a great challenge, 3D cell cultures derived from iPSC are now available and able to partially reproduce the myelination process. We have previously developed a human iPSC-derived 3D brain organoid model (also called BrainSpheres) that contains a high percentage of myelinated axons and is highly reproducible. Here, we have further refined this technology by applying multiple readouts to study myelination disruption. Myelin was assessed by quantifying immunostaining/confocal microscopy of co-localized myelin basic protein (MBP) with neurofilament proteins as well as proteolipid protein 1 (PLP1). Levels of PLP1 were also assessed by Western blot. We identified compounds capable of inducing developmental neurotoxicity by disrupting myelin in a systematic review to evaluate the relevance of our BrainSphere model for the study of the myelination/demyelination processes. Results demonstrated that the positive reference compound (cuprizone) and two of the three potential myelin disruptors tested (Bisphenol A, Tris(1,3-dichloro-2-propyl) phosphate, but not methyl mercury) decreased myelination, while ibuprofen (negative control) had no effect. Here, we define a methodology that allows quantification of myelin disruption and provides reference compounds for chemical-induced myelin disruption.
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Affiliation(s)
- Megan Chesnut
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
| | - Hélène Paschoud
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
| | - Cendrine Repond
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
| | - Lena Smirnova
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
| | - Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
- Center for Alternative to Animla Testing Europe, University of Konstanz, 78464 Konstanz, Germany
| | - Marie-Gabrielle Zurich
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
- Swiss Centre for Applied Human Toxicology (SCAHT), 4055 Basel, Switzerland
| | - Helena T. Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
- Correspondence: (H.T.H.); (D.P.)
| | - David Pamies
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
- Swiss Centre for Applied Human Toxicology (SCAHT), 4055 Basel, Switzerland
- Correspondence: (H.T.H.); (D.P.)
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Chesnut M, Hartung T, Hogberg H, Pamies D. Human Oligodendrocytes and Myelin In Vitro to Evaluate Developmental Neurotoxicity. Int J Mol Sci 2021; 22:7929. [PMID: 34360696 PMCID: PMC8347131 DOI: 10.3390/ijms22157929] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 01/01/2023] Open
Abstract
Neurodevelopment is uniquely sensitive to toxic insults and there are concerns that environmental chemicals are contributing to widespread subclinical developmental neurotoxicity (DNT). Increased DNT evaluation is needed due to the lack of such information for most chemicals in common use, but in vivo studies recommended in regulatory guidelines are not practical for the large-scale screening of potential DNT chemicals. It is widely acknowledged that developmental neurotoxicity is a consequence of disruptions to basic processes in neurodevelopment and that testing strategies using human cell-based in vitro systems that mimic these processes could aid in prioritizing chemicals with DNT potential. Myelination is a fundamental process in neurodevelopment that should be included in a DNT testing strategy, but there are very few in vitro models of myelination. Thus, there is a need to establish an in vitro myelination assay for DNT. Here, we summarize the routes of myelin toxicity and the known models to study this particular endpoint.
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Affiliation(s)
- Megan Chesnut
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
| | - Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
- Center for Alternatives to Animal Testing (CAAT-Europe), University of Konstanz, 78464 Konstanz, Germany
| | - Helena Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
| | - David Pamies
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
- Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
- Swiss Centre for Applied Human Toxicology (SCAHT), 4055 Basel, Switzerland
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Sachana M, Willett C, Pistollato F, Bal-Price A. The potential of mechanistic information organised within the AOP framework to increase regulatory uptake of the developmental neurotoxicity (DNT) in vitro battery of assays. Reprod Toxicol 2021; 103:159-170. [PMID: 34147625 PMCID: PMC8279093 DOI: 10.1016/j.reprotox.2021.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/19/2021] [Accepted: 06/04/2021] [Indexed: 12/24/2022]
Abstract
Current in vivo DNT testing for regulatory purposes is not effective. In vitro assays anchored to key neurodevelopmental processes are available. Development of Adverse Outcome Pathways is required to increase mechanistic understanding of DNT effects. DNT Integrated Approaches to Testing and Assessment for various regulatory purposes should be developed. The OECD Guidance Document on use of in vitro DNT battery of assays is currently under development.
A major challenge in regulatory developmental neurotoxicity (DNT) assessment is lack of toxicological information for many compounds. Therefore, the Test Guidelines programme of the Organisation for Economic Cooperation and Development (OECD) took the initiative to coordinate an international collaboration between diverse stakeholders to consider integration of alternative approaches towards improving the current chemical DNT testing. During the past few years, a series of workshops was organized during which a consensus was reached that incorporation of a DNT testing battery that relies on in vitro assays anchored to key neurodevelopmental processes should be developed. These key developmental processes include neural progenitor cell proliferation, neuronal and oligodendrocyte differentiation, neural cell migration, neurite outgrowth, synaptogenesis and neuronal network formation, as well key events identified in the existing Adverse Outcome Pathways (AOPs). AOPs deliver mechanistic information on the causal links between molecular initiating event, intermediate key events and an adverse outcome of regulatory concern, providing the biological context to facilitate development of Integrated Approaches to Testing and Assessment (IATA) for various regulatory purposes. Developing IATA case studies, using mechanistic information derived from AOPs, is expected to increase scientific confidence for the use of in vitro methods within an IATA, thereby facilitating regulatory uptake. This manuscript summarizes the current state of international efforts to enhance DNT testing by using an in vitro battery of assays focusing on the role of AOPs in informing the development of IATA for different regulatory purposes, aiming to deliver an OECD guidance document on use of in vitro DNT battery of assays that include in vitro data interpretation.
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Affiliation(s)
- Magdalini Sachana
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Co-Operation and Development (OECD), 75775, Paris Cedex 16, France
| | - Catherine Willett
- Humane Society International, 1255 23rd Street NW, Washington, DC, 20037, USA
| | | | - Anna Bal-Price
- European Commission Joint Research Centre (JRC), Ispra, Italy.
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Li RA, Talikka M, Gubian S, Vom Berg C, Martin F, Peitsch MC, Hoeng J, Zupanic A. Systems Toxicology Approach for Assessing Developmental Neurotoxicity in Larval Zebrafish. Front Genet 2021; 12:652632. [PMID: 34211495 PMCID: PMC8239408 DOI: 10.3389/fgene.2021.652632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 05/20/2021] [Indexed: 11/13/2022] Open
Abstract
Adverse outcomes that result from chemical toxicity are rarely caused by dysregulation of individual proteins; rather, they are often caused by system-level perturbations in networks of molecular events. To fully understand the mechanisms of toxicity, it is necessary to recognize the interactions of molecules, pathways, and biological processes within these networks. The developing brain is a prime example of an extremely complex network, which makes developmental neurotoxicity one of the most challenging areas in toxicology. We have developed a systems toxicology method that uses a computable biological network to represent molecular interactions in the developing brain of zebrafish larvae. The network is curated from scientific literature and describes interactions between biological processes, signaling pathways, and adverse outcomes associated with neurotoxicity. This allows us to identify important signaling hubs, pathway interactions, and emergent adverse outcomes, providing a more complete understanding of neurotoxicity. Here, we describe the construction of a zebrafish developmental neurotoxicity network and its validation by integration with publicly available neurotoxicity-related transcriptomic datasets. Our network analysis identified consistent regulation of tumor suppressors p53 and retinoblastoma 1 (Rb1) as well as the oncogene Krüppel-like factor (Klf8) in response to chemically induced developmental neurotoxicity. The developed network can be used to interpret transcriptomic data in a neurotoxicological context.
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Affiliation(s)
- Roman A Li
- Eawag, Dübendorf, Switzerland.,PMI R&D, Philip Morris Products S.A., Neuchâtel, Switzerland
| | - Marja Talikka
- PMI R&D, Philip Morris Products S.A., Neuchâtel, Switzerland
| | - Sylvain Gubian
- PMI R&D, Philip Morris Products S.A., Neuchâtel, Switzerland
| | | | - Florian Martin
- PMI R&D, Philip Morris Products S.A., Neuchâtel, Switzerland
| | | | - Julia Hoeng
- PMI R&D, Philip Morris Products S.A., Neuchâtel, Switzerland
| | - Anze Zupanic
- Eawag, Dübendorf, Switzerland.,National Institute of Biology, Ljubljana, Slovenia
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Marty S, Beekhuijzen M, Charlton A, Hallmark N, Hannas BR, Jacobi S, Melching-Kollmuss S, Sauer UG, Sheets LP, Strauss V, Urbisch D, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny - part II: how can key events of relevant adverse outcome pathways be addressed in toxicological assessments? Crit Rev Toxicol 2021; 51:328-358. [PMID: 34074207 DOI: 10.1080/10408444.2021.1910625] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The current understanding of thyroid-related adverse outcome pathways (AOPs) with adverse neurodevelopmental outcomes in mammals has been reviewed. This served to establish if standard rodent toxicity test methods and in vitro assays allow identifying thyroid-related modes-of-action potentially leading to adverse neurodevelopmental outcomes, and the human relevance of effects - in line with the European Commission's Endocrine Disruptor Criteria. The underlying hypothesis is that an understanding of the key events of relevant AOPs provides insight into differences in incidence, magnitude, or species sensitivity of adverse outcomes. The rodent studies include measurements of serum thyroid hormones, thyroid gland pathology and neurodevelopmental assessments, but do not directly inform on specific modes-of-action. Opportunities to address additional non-routine parameters reflecting critical events of AOPs in toxicological assessments are presented. These parameters appear relevant to support the identification of specific thyroid-related modes-of-action, provided that prevailing technical limitations are overcome. Current understanding of quantitative key event relationships is often weak, but would be needed to determine if the triggering of a molecular initiating event will ultimately result in an adverse outcome. Also, significant species differences in all processes related to thyroid hormone signalling are evident, but the biological implications thereof (including human relevance) are often unknown. In conclusion, careful consideration of the measurement (e.g. timing, method) and interpretation of additional non-routine parameters is warranted. These findings will be used in a subsequent paper to propose a testing strategy to identify if a substance may elicit maternal thyroid hormone imbalance and potentially also neurodevelopmental effects in the progeny.
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Affiliation(s)
- Sue Marty
- The Dow Chemical Company, Midland, MI, USA
| | | | | | | | | | | | | | - Ursula G Sauer
- Scientific Consultancy - Animal Welfare, Neubiberg, Germany
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23
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Hernández‐Jerez A, Adriaanse P, Aldrich A, Berny P, Coja T, Duquesne S, Focks A, Marinovich M, Millet M, Pelkonen O, Pieper S, Tiktak A, Topping C, Widenfalk A, Wilks M, Wolterink G, Crofton K, Hougaard Bennekou S, Paparella M, Tzoulaki I. Development of Integrated Approaches to Testing and Assessment (IATA) case studies on developmental neurotoxicity (DNT) risk assessment. EFSA J 2021. [DOI: 10.2903/j.efsa.2021.6599] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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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. ENVIRONMENTAL SCIENCE & TECHNOLOGY 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] [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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25
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Hougaard KS. Next Generation Reproductive and Developmental Toxicology: Crosstalk Into the Future. FRONTIERS IN TOXICOLOGY 2021; 3:652571. [PMID: 35295122 PMCID: PMC8915852 DOI: 10.3389/ftox.2021.652571] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/17/2021] [Indexed: 12/13/2022] Open
Affiliation(s)
- Karin Sørig Hougaard
- National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Karin Sørig Hougaard
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26
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Vorhees CV, Williams MT, Hawkey AB, Levin ED. Translating Neurobehavioral Toxicity Across Species From Zebrafish to Rats to Humans: Implications for Risk Assessment. FRONTIERS IN TOXICOLOGY 2021; 3:629229. [PMID: 35295117 PMCID: PMC8915800 DOI: 10.3389/ftox.2021.629229] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
There is a spectrum of approaches to neurotoxicological science from high-throughput in vitro cell-based assays, through a variety of experimental animal models to human epidemiological and clinical studies. Each level of analysis has its own advantages and limitations. Experimental animal models give essential information for neurobehavioral toxicology, providing cause-and-effect information regarding risks of neurobehavioral dysfunction caused by toxicant exposure. Human epidemiological and clinical studies give the closest information to characterizing human risk, but without randomized treatment of subjects to different toxicant doses can only give information about association between toxicant exposure and neurobehavioral impairment. In vitro methods give much needed high throughput for many chemicals and mixtures but cannot provide information about toxicant impacts on behavioral function. Crucial to the utility of experimental animal model studies is cross-species translation. This is vital for both risk assessment and mechanistic determination. Interspecies extrapolation is important to characterize from experimental animal models to humans and between different experimental animal models. This article reviews the literature concerning extrapolation of neurobehavioral toxicology from established rat models to humans and from zebrafish a newer experimental model to rats. The functions covered include locomotor activity, emotion, and cognition and the neurotoxicants covered include pesticides, metals, drugs of abuse, flame retardants and polycyclic aromatic hydrocarbons. With more complete understanding of the strengths and limitations of interspecies translation, we can better use animal models to protect humans from neurobehavioral toxicity.
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Affiliation(s)
- Charles V. Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, United States
| | - Michael T. Williams
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, United States
| | - Andrew B. Hawkey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, United States
| | - Edward D. Levin
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, United States
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Toward a Better Testing Paradigm for Developmental Neurotoxicity: OECD Efforts and Regulatory Considerations. BIOLOGY 2021; 10:biology10020086. [PMID: 33498772 PMCID: PMC7912397 DOI: 10.3390/biology10020086] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/09/2021] [Accepted: 01/18/2021] [Indexed: 12/11/2022]
Abstract
Simple Summary It is recognized that the current developmental neurotoxicity (DNT) testing paradigm is not fit-for -purpose for the assessment of a large number of chemicals. In the last two decades there have been scientific advances made for evaluating chemical interactions with the developing nervous system that rely on alternative to animal methods. The Organisation for Economic Co-Operation and Development (OECD) provides a forum to develop internationally harmonised guidance to test and assess chemicals for DNT that is primarily based on cellular models. Given the complexity of the developing nervous system and the availability of a number of non-animal methods to address DNT, integration of data from multiple studies is necessary and an OECD framework for organising existing scientific knowledge can be applied as the canvas of this integration. Herein, we provide a brief overview of the OECD DNT project and summarize various achievements of relevance to the project. The review also presents an opportunity to describe considerations for uptake of the DNT non animal methods in a regulatory context. Abstract Characterization of potential chemical-induced developmental neurotoxicity (DNT) hazard is considered for risk assessment purposes by many regulatory sectors. However, due to test complexity, difficulty in interpreting results and need of substantial resources, the use of the in vivo DNT test guidelines has been limited and animal data on DNT are scarce. To address challenging endpoints such as DNT, the Organisation for Economic Co-Operation and Development (OECD) chemical safety program has been working lately toward the development of integrated approaches for testing and assessment (IATA) that rely on a combination of multiple layers of data (e.g., in vitro, in silico and non-mammalian in vivo models) that are supported by mechanistic knowledge organized according to the adverse outcome pathway (AOP) framework. In 2017, the OECD convened a dedicated OECD expert group to develop a guidance document on the application and interpretation of data derived from a DNT testing battery that relies on key neurodevelopmental processes and is complemented by zebrafish assays. This review will provide a brief overview of the OECD DNT project and summarize various achievements of relevance to the project. The review also presents an opportunity to describe considerations for uptake of the DNT in an in vitro battery in a regulatory context.
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Rosca A, Coronel R, Moreno M, González R, Oniga A, Martín A, López V, González MDC, Liste I. Impact of environmental neurotoxic: current methods and usefulness of human stem cells. Heliyon 2020; 6:e05773. [PMID: 33376823 PMCID: PMC7758368 DOI: 10.1016/j.heliyon.2020.e05773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 11/10/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022] Open
Abstract
The development of central nervous system is a highly coordinated and complex process. Any alteration of this process can lead to disturbances in the structure and function of the brain, which can cause deficits in neurological development, resulting in neurodevelopmental disorders, including, for example, autism or attention-deficit hyperactivity disorder. Exposure to certain chemicals during the fetal period and childhood is known to cause developmental neurotoxicity and has serious consequences that persist into adult life. For regulatory purposes, determination of the potential for developmental neurotoxicity is performed according the OECD Guideline 426, in which the test substance is administered to animals during gestation and lactation. However, these animal models are expensive, long-time consuming and may not reflect the physiology in humans; that makes it an unsustainable model to test the large amount of existing chemical products, hence alternative models to the use of animals are needed. One of the most promising methods is based on the use of stem cell technology. Stem cells are undifferentiated cells with the ability to self-renew and differentiate into more specialized cell types. Because of these properties, these cells have gained increased attention as possible therapeutic agents or as disease models. Here, we provide an overview of the current models both animal and cellular, available to study developmental neurotoxicity and review in more detail the usefulness of human stem cells, their properties and how they are becoming an alternative to evaluate and study the mechanisms of action of different environmental toxicants.
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Affiliation(s)
- Andreea Rosca
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC), Instituto de Salud Carlos III, Madrid, Spain
- Toxicología Ambiental, Centro Nacional de Sanidad Ambiental, Instituto de Salud Carlos III, Madrid, Spain
| | - Raquel Coronel
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Miryam Moreno
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Rosa González
- Unidad de Biología Computacional, Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Andreea Oniga
- Toxicología Ambiental, Centro Nacional de Sanidad Ambiental, Instituto de Salud Carlos III, Madrid, Spain
| | - Alberto Martín
- Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid, Spain
| | - Victoria López
- Unidad de Biología Computacional, Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC), Instituto de Salud Carlos III, Madrid, Spain
| | - María del Carmen González
- Toxicología Ambiental, Centro Nacional de Sanidad Ambiental, Instituto de Salud Carlos III, Madrid, Spain
| | - Isabel Liste
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC), Instituto de Salud Carlos III, Madrid, Spain
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Di Consiglio E, Pistollato F, Mendoza-De Gyves E, Bal-Price A, Testai E. Integrating biokinetics and in vitro studies to evaluate developmental neurotoxicity induced by chlorpyrifos in human iPSC-derived neural stem cells undergoing differentiation towards neuronal and glial cells. Reprod Toxicol 2020; 98:174-188. [PMID: 33011216 PMCID: PMC7772889 DOI: 10.1016/j.reprotox.2020.09.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/17/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022]
Abstract
Human iPSC-derived NSCs undergoing differentiation possess some metabolic competence. CPF entered the cells and was biotrasformed into its two main metabolites (CPFO and TCP). After repeated exposure, very limited bioaccumulation of CPF was observed. Treatment with CPF decreased neurite outgrowth, synapse number and electrical activity. Treatment with CPF increased BDNF levels and the percentage of astrocytes.
For some complex toxicological endpoints, chemical safety assessment has conventionally relied on animal testing. Apart from the ethical issues, also scientific considerations have been raised concerning the traditional approach, highlighting the importance for considering real life exposure scenario. Implementation of flexible testing strategies, integrating multiple sources of information, including in vitro reliable test methods and in vitro biokinetics, would enhance the relevance of the obtained results. Such an approach could be pivotal in the evaluation of developmental neurotoxicity (DNT), especially when applied to human cell-based models, mimicking key neurodevelopmental processes, relevant to human brain development. Here, we integrated the kinetic behaviour with the toxicodynamic alterations of chlorpyrifos (CPF), such as in vitro endpoints specific for DNT evaluation, after repeated exposure during differentiation of human neural stem cells into a mixed culture of neurons and astrocytes. The upregulation of some cytochrome P450 and glutathione S-transferase genes during neuronal differentiation and the formation of the two major CPF metabolites (due to bioactivation and detoxification) supported the metabolic competence of the used in vitro model. The alterations in the number of synapses, neurite outgrowth, brain derived neurotrophic factor, the proportion of neurons and astrocytes, as well as spontaneous electrical activity correlated well with the CPF ability to enter the cells and be bioactivated to CPF-oxon. Overall, our results confirm that combining in vitro biokinetics and assays to evaluate effects on neurodevelopmental endpoints in human cells should be regarded as a key strategy for a quantitative characterization of DNT effects.
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Affiliation(s)
- Emma Di Consiglio
- Istituto Superiore di Sanità, Environment and Health Department, Mechanisms, Biomarkers and Models Unit, Rome, Italy
| | | | | | - Anna Bal-Price
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Emanuela Testai
- Istituto Superiore di Sanità, Environment and Health Department, Mechanisms, Biomarkers and Models Unit, Rome, Italy
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Paparella M, Bennekou SH, Bal-Price A. An analysis of the limitations and uncertainties of in vivo developmental neurotoxicity testing and assessment to identify the potential for alternative approaches. Reprod Toxicol 2020; 96:327-336. [PMID: 32781019 DOI: 10.1016/j.reprotox.2020.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/27/2020] [Accepted: 08/05/2020] [Indexed: 10/23/2022]
Abstract
Limitations of regulatory in vivo developmental neurotoxicity (DNT) testing and assessment are well known, such as the 3Rs conflict, low throughput, high costs, high specific expertise needed and the lack of deeper mechanistic information. Moreover, the standard in vivo DNT data variability and in the experimental animal to human real life extrapolation is uncertain. Here, knowledge about these limitations and uncertainties is systematically summarized using a tabular OECD format. We also outline a hypothesis how alternative, fit-for-purpose Integrated Approaches to Testing and Assessment (IATAs) for DNT could improve current standard animal testing: Relative gains in 3Rs compliance, reduced costs, higher throughput, improved basic study design, higher standardization of testing and assessment and validation without 3Rs conflict, increasing the availability and reliability of DNT data. This could allow a more reliable comparative toxicity assessment over a larger proportion of chemicals within our global environment. The use of early, mechanistic, sensitive indicators for potential DNT could better support human safety assessment and mixture extrapolation. Using kinetic modelling ideally these could provide - eventually context dependent - at least the same level of human health protection. Such new approaches could also lead to a new mechanistic understanding for chemical safety, permitting determination of a dose that is likely not to trigger defined toxicity traits or pathways, rather than a dose not causing the current apical organism endpoints. The manuscript shall motivate and guide the development of new alternative methods for IATAs with diverse applications and support decision-making for their regulatory acceptance.
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Affiliation(s)
- Martin Paparella
- Division of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
| | | | - Anna Bal-Price
- European Commission, Joint Research Centre (JRC), Ispra, Italy
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Predicting In Vitro Neurotoxicity Induced by Nanoparticles Using Machine Learning. Int J Mol Sci 2020; 21:ijms21155280. [PMID: 32722414 PMCID: PMC7432486 DOI: 10.3390/ijms21155280] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 12/31/2022] Open
Abstract
The practice of non-testing approaches in nanoparticles hazard assessment is necessary to identify and classify potential risks in a cost effective and timely manner. Machine learning techniques have been applied in the field of nanotoxicology with encouraging results. A neurotoxicity classification model for diverse nanoparticles is presented in this study. A data set created from multiple literature sources consisting of nanoparticles physicochemical properties, exposure conditions and in vitro characteristics is compiled to predict cell viability. Pre-processing techniques were applied such as normalization methods and two supervised instance methods, a synthetic minority over-sampling technique to address biased predictions and production of subsamples via bootstrapping. The classification model was developed using random forest and goodness-of-fit with additional robustness and predictability metrics were used to evaluate the performance. Information gain analysis identified the exposure dose and duration, toxicological assay, cell type, and zeta potential as the five most important attributes to predict neurotoxicity in vitro. This is the first tissue-specific machine learning tool for neurotoxicity prediction caused by nanoparticles in in vitro systems. The model performs better than non-tissue specific models.
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Retinoids and developmental neurotoxicity: Utilizing toxicogenomics to enhance adverse outcome pathways and testing strategies. Reprod Toxicol 2020; 96:102-113. [PMID: 32544423 DOI: 10.1016/j.reprotox.2020.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 06/02/2020] [Accepted: 06/07/2020] [Indexed: 12/17/2022]
Abstract
The use of genomic approaches in toxicological studies has greatly increased our ability to define the molecular profiles of environmental chemicals associated with developmental neurotoxicity (DNT). Integration of these approaches with adverse outcome pathways (AOPs), a framework that translates environmental exposures to adverse developmental phenotypes, can potentially inform DNT testing strategies. Here, using retinoic acid (RA) as a case example, we demonstrate that the integration of toxicogenomic profiles into the AOP framework can be used to establish a paradigm for chemical testing. RA is a critical regulatory signaling molecule involved in multiple aspects of mammalian central nervous system (CNS) development, including hindbrain formation/patterning and neuronal differentiation, and imbalances in RA signaling pathways are linked with DNT. While the mechanisms remain unresolved, environmental chemicals can cause DNT by disrupting the RA signaling pathway. First, we reviewed literature evidence of RA and other retinoid exposures and DNT to define a provisional AOP related to imbalances in RA embryonic bioavailability and hindbrain development. Next, by integrating toxicogenomic datasets, we defined a relevant transcriptomic signature associated with RA-induced developmental neurotoxicity (RA-DNT) in human and rodent models that was tested against zebrafish model data, demonstrating potential for integration into an AOP framework. Finally, we demonstrated how these approaches may be systematically utilized to identify chemical hazards by testing the RA-DNT signature against azoles, a proposed class of compounds that alters RA-signaling. The provisional AOP from this study can be expanded in the future to better define DNT biomarkers relevant to RA signaling and toxicity.
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Shafer TJ, Brown JP, Lynch B, Davila-Montero S, Wallace K, Friedman KP. Evaluation of Chemical Effects on Network Formation in Cortical Neurons Grown on Microelectrode Arrays. Toxicol Sci 2020; 169:436-455. [PMID: 30816951 DOI: 10.1093/toxsci/kfz052] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Thousands of chemicals to which humans are potentially exposed have not been evaluated for potential developmental neurotoxicity (DNT), driving efforts to develop a battery of in vitro screening approaches for DNT hazard. Here, 136 unique chemicals were evaluated for potential DNT hazard using a network formation assay (NFA) in cortical cells grown on microelectrode arrays. The effects of chemical exposure from 2 h postplating through 12 days in vitro (DIV) on network formation were evaluated at DIV 5, 7, 9, and 12, with cell viability assessed at DIV 12. Only 82 chemicals altered at least 1 network development parameter. Assay results were reproducible; 10 chemicals tested as biological replicates yielded qualitative results that were 100% concordant, with consistent potency values. Toxicological tipping points were determined for 58 chemicals and were similar to or lower than the lowest 50% effect concentrations (EC50) for all parameters. When EC50 and tipping point values from the NFA were compared to the range of potencies observed in ToxCast assays, the NFA EC50 values were less than the lower quartile for ToxCast assay potencies for a subset of chemicals, many of which are acutely neurotoxic in vivo. For 13 chemicals with available in vivo DNT data, estimated administered equivalent doses based on NFA results were similar to or lower than administered doses in vivo. Collectively, these results indicate that the NFA is sensitive to chemicals acting on nervous system function and will be a valuable contribution to an in vitro DNT screening battery.
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Affiliation(s)
- Timothy J Shafer
- Integrated Systems Toxicology Division, NHEERL, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711
| | - Jasmine P Brown
- Integrated Systems Toxicology Division, NHEERL, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711.,Graduate Program in Public Health, University of Michigan, Ann Arbor, MI
| | - Brittany Lynch
- Tandon School of Engineering, New York University, Brooklyn, New York 11201
| | - Sylmarie Davila-Montero
- Department of Electrical and Computer Engineering, Michigan State University, E. Lansing, Michigan 48824
| | - Kathleen Wallace
- Integrated Systems Toxicology Division, NHEERL, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711
| | - Katie Paul Friedman
- National Center for Computational Toxicology, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711
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Fueta Y, Ueno S, Ishidao T, Yoshida Y, Kanda Y, Hori H. Exposure to 1-bromopropane vapors during pregnancy enhances the development of hippocampal neuronal excitability in rat pups during lactation. J Occup Health 2020; 62:e12135. [PMID: 32715571 PMCID: PMC7383040 DOI: 10.1002/1348-9585.12135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/18/2020] [Accepted: 05/19/2020] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Although 1-Bromopropane (1-BP) exposure has been reported to cause neurotoxicity in adult humans and animals, its effects on the development of the central nervous system remain unclear. Recently, we reported delayed developmental neurotoxicity (DNT) upon 1-BP exposure in rats. Here we aimed to study the effect of prenatal 1-BP exposure on the hippocampal excitability in the juvenile offspring. METHODS Pregnant Wistar rats were exposed to vaporized 1-BP for 20 days (6 h/d) with concentrations of 0 (control), 400, or 700 ppm. Hippocampal slices were prepared from male offspring during postnatal days (PNDs) 13, 14, and 15. Field excitatory postsynaptic potential (fEPSP) and population spike (PS) were recorded simultaneously from the CA1 region. RESULTS In the exposed groups, the stimulation/response relationships of fEPSP slope and PS amplitude were enhanced more than in the control group at PND 14. Analysis of fEPSP-spike coupling demonstrated increased values of Top and Eslope50 in the exposed groups. Real-time PCR analysis showed a significant increase in the mRNA levels of the adult type Nav 1.1 Na+ channel subunit and the GluR1 glutamate receptor subunit in the hippocampus of the 700 ppm group at PND 14. CONCLUSIONS Our results provide evidence that prenatal exposure to 1-BP accelerates developmental enhancement of hippocampal excitability in the pups before eye-opening. The current study suggests that our evaluation method of DNT is applicable to the industrial chemical 1-BP.
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Affiliation(s)
- Yukiko Fueta
- Department of Environmental Management and ControlSchool of Health SciencesUniversity of Occupational and Environmental HealthKitakyushuJapan
| | - Susumu Ueno
- Department of PharmacologySchool of MedicineUniversity of Occupational and Environmental HealthKitakyushuJapan
| | - Toru Ishidao
- Department of Environmental Management and ControlSchool of Health SciencesUniversity of Occupational and Environmental HealthKitakyushuJapan
| | - Yasuhiro Yoshida
- Department of Immunology and ParasitologySchool of MedicineUniversity of Occupational and Environmental HealthKitakyushuJapan
| | - Yasunari Kanda
- Division of PharmacologyNational Institute of Health SciencesKawasakiJapan
| | - Hajime Hori
- Department of Environmental Management and ControlSchool of Health SciencesUniversity of Occupational and Environmental HealthKitakyushuJapan
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Sachana M, Bal-Price A, Crofton KM, Bennekou SH, Shafer TJ, Behl M, Terron A. International Regulatory and Scientific Effort for Improved Developmental Neurotoxicity Testing. Toxicol Sci 2019; 167:45-57. [PMID: 30476307 DOI: 10.1093/toxsci/kfy211] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The Organisation for Economic Co-Operation and Development (OECD) coordinates international efforts to enhance developmental neurotoxicity (DNT) testing. In most regulatory sectors, including the ones dealing with pesticides and industrial chemicals registration, historical use of the in vivo DNT test guideline has been limited. Current challenges include a lack of DNT data and mechanistic information for thousands of chemicals, and difficulty in interpreting results. A series of workshops in the last decade has paved the way for a consensus among stakeholders that there is need for a DNT testing battery that relies on in vitro endpoints (proliferation, differentiation, synaptogenesis, etc.) and is complemented by alternative species (eg, zebrafish) assays. Preferably, a battery of in vitro and alternative assays should be anchored toward mechanistic relevance for applying an integrated approach for testing and assessment (IATA) framework. Specific activities have been initiated to facilitate this OECD project: the collation of available DNT in vitro methods and their scoring for readiness; the selection of these methods to form a DNT testing battery; the generation of a reference set of chemicals that will be tested using the battery; the case studies exemplifying how DNT in vitro data can be interpreted; and the development of an OECD guidance document. This manuscript highlights these international efforts and activities.
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Affiliation(s)
- Magdalini Sachana
- Organisation for Economic Co-Operation and Development (OECD), 75775 Paris Cedex 16, France
| | - Anna Bal-Price
- European Commission Joint Research Centre, Health, Consumers and Reference Materials, Unit Chemicals Safety and Alternative Methods I-21027 Ispra (VA), Italy
| | | | - Susanne H Bennekou
- Danish Environmental Protection Agency, Haraldsgade 53, DK - 2100, Copenhagen, Denmark
| | - Timothy J Shafer
- U.S. Environmental Protection Agency (EPA), Office of Research and Development, Research Triangle Park, North Carolina 27711, USA
| | - Mamta Behl
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences Research Triangle Park, North Carolina, 27709 USA
| | - Andrea Terron
- European Food Safety Authority, Via Carlo Magno, 1A, 43126, Parma, Italy
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Zindler F, Beedgen F, Braunbeck T. Time-course of coiling activity in zebrafish (Danio rerio) embryos exposed to ethanol as an endpoint for developmental neurotoxicity (DNT) - Hidden potential and underestimated challenges. CHEMOSPHERE 2019; 235:12-20. [PMID: 31254777 DOI: 10.1016/j.chemosphere.2019.06.154] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 06/09/2023]
Abstract
Detection of developmental neurotoxicity (DNT) has been recognized as a major challenge by regulatory bodies and science. In search of sensitive and specific test methods, spontaneous tail coiling of embryonic zebrafish has been recommended as a promising tool for identification of DNT-inducing chemicals. The present study was designed to develop a protocol for a prolonged test to study neurotoxicity during the entire development of coiling movement in zebrafish embryos. Ambient illumination was found to modulate coiling activity from the very onset of tail movements representing the earliest behavioral response to light possible in zebrafish. In the dark, embryos displayed increased coiling activity in a way known from photokinesis, a stereotypical element of the visual motor response. Elevated coiling activity during dark phases allows for the development of test strategies that integrate later coiling movements under the control of a further developed nervous system. Furthermore, zebrafish embryos were exposed to ethanol, and coiling activity was analyzed according to the new test protocol. Exposure of embryos to non-teratogenic concentrations of ethanol (0.4-1%) resulted in a delay of the onset of coiling activity and heartbeat. Moreover, ethanol produced a dose-dependent increase in coiling frequency at 26 h post-fertilization, indicating the involvement of neurotoxic mechanisms. Analysis of coiling activity during prolonged exposure allowed for (1) attributing effects on coiling activity to different mechanisms and (2) preventing false interpretation of results. Further research is needed to verify the potential of this test protocol to distinguish between different mechanisms of neurotoxicity.
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Affiliation(s)
- Florian Zindler
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| | - Franziska Beedgen
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
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Liu Z, Chandrasekaran A, Becker JM. Determination of offspring NOAEL for zeta-cypermethrin using internal exposure data from rat developmental neurotoxicity studies. Regul Toxicol Pharmacol 2019; 108:104425. [PMID: 31325535 DOI: 10.1016/j.yrtph.2019.104425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/01/2019] [Accepted: 07/16/2019] [Indexed: 11/17/2022]
Abstract
Developmental neurotoxicity (DNT) studies via dietary method of administration have been conducted for zeta-cypermethrin, a pyrethroid insecticide. The objectives of the current study were to determine the toxicokinetics (TK) of zeta-cypermethrin in postnatal day (PND) 11, 21 and 90 rats after gavage doses and use the internal exposure data from the DNT and TK studies to calculate an offspring NOAEL in mg/kg/day during lactation. The DNT studies showed that zeta-cypermethrin is not a developmental neurotoxicant. The NOAEL for maternal and offspring was determined to be 125 ppm (9.0 and 21.4 mg/kg/day for dams during gestation and lactation, respectively), based on systemic toxicity of reductions in maternal body weight, body weight gains and food consumption and offspring body weight at 300 ppm (LOAEL). The TK data from the gavage study showed that dose normalized Cmax and AUC is approximately 3-fold and 2-fold higher in PND 11 and 21 than those in PND 90 rats. By using the mean maternal/offspring plasma concentrations (535/245 ng/mL) during lactation day LD/PND 5-21 from the range-finding DNT studies, a conservative 3.1X relative TK factor (exposure ratio from the gavage study) and equation 3.1 × 535/21.4 = 245/x, the offspring NOAEL of 125 ppm was calculated to be 3.2 mg/kg/day during lactation. The offspring NOAEL based on internal exposure data from DNT studies and TK data after gavage doses is considered conservative for risk assessment for all human populations including infants and children for zeta-cypermethrin.
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Affiliation(s)
- Zhiwei Liu
- FMC Corporation, Stine Research Center, 1090 Elkton Rd, Newark, DE, 19711, USA.
| | | | - John M Becker
- FMC Corporation, Stine Research Center, 1090 Elkton Rd, Newark, DE, 19711, USA
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38
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Qian B, Wang C, Zhao C, Jiang R, Song J. Effects of maternal exposure to BDE209 on neuronal development and transcription of iodothyronine deiodinase in offspring mice. Toxicol Mech Methods 2019; 29:569-579. [DOI: 10.1080/15376516.2019.1624906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Bo Qian
- Department of Occupational and Environmental Health, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
- Guangxi Colleges and University Key Laboratory of Preventive Medicine, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
| | - Chengqiang Wang
- Department of Occupational and Environmental Health, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
- Guangxi Colleges and University Key Laboratory of Preventive Medicine, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
| | - Chaochao Zhao
- Guangxi Colleges and University Key Laboratory of Preventive Medicine, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
- Department of Nutrition and Food Hygiene, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
| | - Rongjuan Jiang
- Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, 541004, People’s Republic of China
| | - Jiale Song
- Guangxi Colleges and University Key Laboratory of Preventive Medicine, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
- Department of Nutrition and Food Hygiene, Guilin Medical University, Guilin, Guangxi, People’s Republic of China
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Shafer TJ. Application of Microelectrode Array Approaches to Neurotoxicity Testing and Screening. ADVANCES IN NEUROBIOLOGY 2019; 22:275-297. [PMID: 31073941 DOI: 10.1007/978-3-030-11135-9_12] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neurotoxicity can be defined by the ability of a drug or chemical to alter the physiology, biochemistry, or structure of the nervous system in a manner that may negatively impact the health or function of the individual. Electrophysiological approaches have been utilized to study the mechanisms underlying neurotoxic actions of drugs and chemicals for over 50 years, and in more recent decades, high-throughput patch-clamp approaches have been utilized by the pharmaceutical industry for drug development. The use of microelectrode array recordings to study neural network electrophysiology is a relatively newer approach, with commercially available systems becoming available only in the early 2000s. However, MEAs have been rapidly adopted as a useful approach for neurotoxicity testing. In this chapter, I will review the use of MEA approaches as they have been applied to the field of neurotoxicity testing, especially as they have been applied to the need to screen large numbers of chemicals for neurotoxicity and developmental neurotoxicity. In addition, I will also identify challenges for the field that when addressed will improve the utility of MEA approaches for toxicity testing.
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Affiliation(s)
- Timothy J Shafer
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory (NHEERL), US EPA, Research Triangle Park, NC, USA.
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40
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Sachana M, Rolaki A, Bal-Price A. Development of the Adverse Outcome Pathway (AOP): Chronic binding of antagonist to N-methyl-d-aspartate receptors (NMDARs) during brain development induces impairment of learning and memory abilities of children. Toxicol Appl Pharmacol 2018; 354:153-175. [PMID: 29524501 PMCID: PMC6095943 DOI: 10.1016/j.taap.2018.02.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 01/06/2023]
Abstract
The Adverse Outcome Pathways (AOPs) are designed to provide mechanistic understanding of complex biological systems and pathways of toxicity that result in adverse outcomes (AOs) relevant to regulatory endpoints. AOP concept captures in a structured way the causal relationships resulting from initial chemical interaction with biological target(s) (molecular initiating event) to an AO manifested in individual organisms and/or populations through a sequential series of key events (KEs), which are cellular, anatomical and/or functional changes in biological processes. An AOP provides the mechanistic detail required to support chemical safety assessment, the development of alternative methods and the implementation of an integrated testing strategy. An example of the AOP relevant to developmental neurotoxicity (DNT) is described here following the requirements of information defined by the OECD Users' Handbook Supplement to the Guidance Document for developing and assessing AOPs. In this AOP, the binding of an antagonist to glutamate receptor N-methyl-d-aspartate (NMDAR) receptor is defined as MIE. This MIE triggers a cascade of cellular KEs including reduction of intracellular calcium levels, reduction of brain derived neurotrophic factor release, neuronal cell death, decreased glutamate presynaptic release and aberrant dendritic morphology. At organ level, the above mentioned KEs lead to decreased synaptogenesis and decreased neuronal network formation and function causing learning and memory deficit at organism level, which is defined as the AO. There are in vitro, in vivo and epidemiological data that support the described KEs and their causative relationships rendering this AOP relevant to DNT evaluation in the context of regulatory purposes.
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Affiliation(s)
| | | | - Anna Bal-Price
- European Commission, Joint Research Centre, Ispra, Italy.
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Bal-Price A, Pistollato F, Sachana M, Bopp SK, Munn S, Worth A. Strategies to improve the regulatory assessment of developmental neurotoxicity (DNT) using in vitro methods. Toxicol Appl Pharmacol 2018; 354:7-18. [PMID: 29476865 PMCID: PMC6095942 DOI: 10.1016/j.taap.2018.02.008] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/05/2018] [Accepted: 02/13/2018] [Indexed: 01/23/2023]
Abstract
Currently, the identification of chemicals that have the potential to induce developmental neurotoxicity (DNT) is based on animal testing. Since at the regulatory level, systematic testing of DNT is not a standard requirement within the EU or USA chemical legislation safety assessment, DNT testing is only performed in higher tiered testing triggered based on chemical structure activity relationships or evidence of neurotoxicity in systemic acute or repeated dose toxicity studies. However, these triggers are rarely used and, in addition, do not always serve as reliable indicators of DNT, as they are generally based on observations in adult rodents. Therefore, there is a pressing need for developing alternative methodologies that can reliably support identification of DNT triggers, and more rapidly and cost-effectively support the identification and characterization of chemicals with DNT potential. We propose to incorporate mechanistic knowledge and data derived from in vitro studies to support various regulatory applications including: (a) the identification of potential DNT triggers, (b) initial chemical screening and prioritization, (c) hazard identification and characterization, (d) chemical biological grouping, and (e) assessment of exposure to chemical mixtures. Ideally, currently available cellular neuronal/glial models derived from human induced pluripotent stem cells (hiPSCs) should be used as they allow evaluation of chemical impacts on key neurodevelopmental processes, by reproducing different windows of exposure during human brain development. A battery of DNT in vitro test methods derived from hiPSCs could generate valuable mechanistic data, speeding up the evaluation of thousands of compounds present in industrial, agricultural and consumer products that lack safety data on DNT potential.
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Affiliation(s)
- Anna Bal-Price
- European Commission, Joint Research Centre (JRC), Ispra, Italy.
| | | | - Magdalini Sachana
- Organisation for Economic Co-operation and Development (OECD), 2 rue André Pascal, 75775 Paris, Cedex 16, France
| | | | - Sharon Munn
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Andrew Worth
- European Commission, Joint Research Centre (JRC), Ispra, Italy
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42
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Audouze K, Taboureau O, Grandjean P. A systems biology approach to predictive developmental neurotoxicity of a larvicide used in the prevention of Zika virus transmission. Toxicol Appl Pharmacol 2018; 354:56-63. [PMID: 29476864 PMCID: PMC6087490 DOI: 10.1016/j.taap.2018.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/09/2018] [Accepted: 02/20/2018] [Indexed: 01/26/2023]
Abstract
The need to prevent developmental brain disorders has led to an increased interest in efficient neurotoxicity testing. When an epidemic of microcephaly occurred in Brazil, Zika virus infection was soon identified as the likely culprit. However, the pathogenesis appeared to be complex, and a larvicide used to control mosquitoes responsible for transmission of the virus was soon suggested as an important causative factor. Yet, it is challenging to identify relevant and efficient tests that are also in line with ethical research defined by the 3Rs rule (Replacement, Reduction and Refinement). Especially in an acute situation like the microcephaly epidemic, where little toxicity documentation is available, new and innovative alternative methods, whether in vitro or in silico, must be considered. We have developed a network-based model using an integrative systems biology approach to explore the potential developmental neurotoxicity, and we applied this method to examine the larvicide pyriproxyfen widely used in the prevention of Zika virus transmission. Our computational model covered a wide range of possible pathways providing mechanistic hypotheses between pyriproxyfen and neurological disorders via protein complexes, thus adding to the plausibility of pyriproxyfen neurotoxicity. Although providing only tentative evidence and comparisons with retinoic acid, our computational systems biology approach is rapid and inexpensive. The case study of pyriproxyfen illustrates its usefulness as an initial or screening step in the assessment of toxicity potentials of chemicals with incompletely known toxic properties.
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Affiliation(s)
- Karine Audouze
- INSERM UMR-S 973, 75013 Paris, France; University of Paris Diderot, 75013 Paris, France
| | - Olivier Taboureau
- INSERM UMR-S 973, 75013 Paris, France; University of Paris Diderot, 75013 Paris, France
| | - Philippe Grandjean
- Harvard T.H. Chan School of Public Health, Boston, MA, USA; University of Southern Denmark, Odense, Denmark.
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Sachana M, Rolaki A, Bal-Price A. Development of the Adverse Outcome Pathway (AOP): Chronic binding of antagonist to N-methyl-d-aspartate receptors (NMDARs) during brain development induces impairment of learning and memory abilities of children. Toxicol Appl Pharmacol 2018; 354:153-175. [PMID: 29524501 DOI: 10.1787/5jlsqs5hcrmq-en] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 05/20/2023]
Abstract
The Adverse Outcome Pathways (AOPs) are designed to provide mechanistic understanding of complex biological systems and pathways of toxicity that result in adverse outcomes (AOs) relevant to regulatory endpoints. AOP concept captures in a structured way the causal relationships resulting from initial chemical interaction with biological target(s) (molecular initiating event) to an AO manifested in individual organisms and/or populations through a sequential series of key events (KEs), which are cellular, anatomical and/or functional changes in biological processes. An AOP provides the mechanistic detail required to support chemical safety assessment, the development of alternative methods and the implementation of an integrated testing strategy. An example of the AOP relevant to developmental neurotoxicity (DNT) is described here following the requirements of information defined by the OECD Users' Handbook Supplement to the Guidance Document for developing and assessing AOPs. In this AOP, the binding of an antagonist to glutamate receptor N-methyl-d-aspartate (NMDAR) receptor is defined as MIE. This MIE triggers a cascade of cellular KEs including reduction of intracellular calcium levels, reduction of brain derived neurotrophic factor release, neuronal cell death, decreased glutamate presynaptic release and aberrant dendritic morphology. At organ level, the above mentioned KEs lead to decreased synaptogenesis and decreased neuronal network formation and function causing learning and memory deficit at organism level, which is defined as the AO. There are in vitro, in vivo and epidemiological data that support the described KEs and their causative relationships rendering this AOP relevant to DNT evaluation in the context of regulatory purposes.
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Affiliation(s)
| | | | - Anna Bal-Price
- European Commission, Joint Research Centre, Ispra, Italy.
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44
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Menzner AK, Gilbert DF. A Protocol for In Vitro High-Throughput Chemical Susceptibility Screening in Differentiating NT2 Stem Cells. Methods Mol Biol 2018; 1601:61-70. [PMID: 28470517 DOI: 10.1007/978-1-4939-6960-9_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The incidence of neurological diseases including learning and developmental disorders has increased in recent years. Concurrently, the number and volume of worldwide registered and traded chemicals have also increased. There is a broad consensus that the developing brain is particularly sensitive to damage by chemicals and that evaluation of chemicals for developmental toxicity or neurotoxicity is critical to human health. Human pluripotent embryonal carcinoma (NTERA-2 or NT2) cells are increasingly considered as a suitable model for in vitro developmental toxicity and neurotoxicity (DT/DNT) studies as they undergo neuronal differentiation upon stimulation with retinoic acid (RA) and allow toxicity assessment at different stages of maturation. Here we describe a protocol for cell fitness screening in differentiating NT2 cells based on the analysis of intracellular ATP levels allowing for the identification of chemicals which are potentially harmful to the developing brain. The described method is suitable to be adapted to low-, medium-, and high-throughput screening and allows multiplexing with other cell fitness indicators. While the presented protocol focuses on cell fitness screening in human pluripotent stem cells it may also be applied to other in vitro models.
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Affiliation(s)
- Ann-Katrin Menzner
- Department of Internal Medicine 5, University Medical Center Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Daniel F Gilbert
- Friedrich-Alexander University (FAU) Erlangen-Nürnberg, Institute of Medical Biotechnology, Paul-Gordan-Street 3, 91052, Erlangen, Germany.
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Terron A, Bennekou SH. Towards a regulatory use of alternative developmental neurotoxicity testing (DNT). Toxicol Appl Pharmacol 2018; 354:19-23. [PMID: 29454059 DOI: 10.1016/j.taap.2018.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 01/24/2018] [Accepted: 02/02/2018] [Indexed: 02/08/2023]
Abstract
There is a need for a more effective Developmental Neurotoxicity (DNT) screening which is scientifically driven by the fact that the developing nervous system might be more sensitive to exposures to some hazardous chemical. Additional concern comes from the recent societal concerns that toxic chemicals can contribute to the prevalence of neurodevelopment disabilities. Consequently, hazard identification and actions to reduce exposure to these chemicals is a priority in chemical risk assessment. To reach this goal a cost-efficient testing strategy based on a reliable in-vitro testing battery should be developed. Although this goal is representing a huge challenge in risk assessment, available data and methodologies are supporting the ultimate aim of developing a predictive model able to respond to different regulatory based problem formulations.
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Fritsche E, Grandjean P, Crofton KM, Aschner M, Goldberg A, Heinonen T, Hessel EVS, Hogberg HT, Bennekou SH, Lein PJ, Leist M, Mundy WR, Paparella M, Piersma AH, Sachana M, Schmuck G, Solecki R, Terron A, Monnet-Tschudi F, Wilks MF, Witters H, Zurich MG, Bal-Price A. Consensus statement on the need for innovation, transition and implementation of developmental neurotoxicity (DNT) testing for regulatory purposes. Toxicol Appl Pharmacol 2018; 354:3-6. [PMID: 29447839 PMCID: PMC6097873 DOI: 10.1016/j.taap.2018.02.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 02/09/2018] [Accepted: 02/10/2018] [Indexed: 01/15/2023]
Abstract
This consensus statement voices the agreement of scientific stakeholders from regulatory agencies, academia and industry that a new framework needs adopting for assessment of chemicals with the potential to disrupt brain development. An increased prevalence of neurodevelopmental disorders in children has been observed that cannot solely be explained by genetics and recently pre- and postnatal exposure to environmental chemicals has been suspected as a causal factor. There is only very limited information on neurodevelopmental toxicity, leaving thousands of chemicals, that are present in the environment, with high uncertainty concerning their developmental neurotoxicity (DNT) potential. Closing this data gap with the current test guideline approach is not feasible, because the in vivo bioassays are far too resource-intensive concerning time, money and number of animals. A variety of in vitro methods are now available, that have the potential to close this data gap by permitting mode-of-action-based DNT testing employing human stem cells-derived neuronal/glial models. In vitro DNT data together with in silico approaches will in the future allow development of predictive models for DNT effects. The ultimate application goals of these new approach methods for DNT testing are their usage for different regulatory purposes. An increased prevalence of neurodevelopmental disorders in children is observed. There is very limited information on neurodevelopmental toxicity (DNT) induced by environmental chemicals. A new framework is required for assessment of chemicals with the potential to disrupt brain development. In vitro DNT data together with in silico approaches should be used for regulatory purposes.
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Affiliation(s)
- Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Philippe Grandjean
- University of Southern Denmark, Harvard T.H. Chan School of Public Health, USA
| | | | | | - Alan Goldberg
- Bloomberg School of Public Health, Founding Director (Emeritus) of Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, USA; Global Food Ethics, Johns Hopkins University, Baltimore, USA
| | - Tuula Heinonen
- Finnish Centre for Alternative Methods (FICAM), University of Tampere, Tampere, Finland
| | - Ellen V S Hessel
- National Institute for Public Health and the Environment, RIVM Center for Health Protection, Bilthoven, Netherlands
| | - Helena T Hogberg
- Centre for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, USA
| | | | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, USA
| | - Marcel Leist
- CAAT - Centre for Alternatives to Animal Testing, University of Konstanz, Konstanz, Germany
| | | | | | - Aldert H Piersma
- RIVM Center for Health Protection, Bilthoven and Institute for Risk Assessment Sciences, Utrecht University, Utrecht, Netherlands
| | - Magdalini Sachana
- Organisation for Economic Co-operation and Development (OECD), Paris, France
| | | | - Roland Solecki
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | | | | | - Martin F Wilks
- SCAHT - Swiss Centre for Applied Human Toxicology, University of Basel, Basel, Switzerland
| | - Hilda Witters
- VITO, Flemish Institute for Technological Research, Unit Environmental Risk and Health, Belgium
| | | | - Anna Bal-Price
- European Commission -DG Joint Research Centre (JRC), Ispra, Italy.
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Legradi JB, Di Paolo C, Kraak MHS, van der Geest HG, Schymanski EL, Williams AJ, Dingemans MML, Massei R, Brack W, Cousin X, Begout ML, van der Oost R, Carion A, Suarez-Ulloa V, Silvestre F, Escher BI, Engwall M, Nilén G, Keiter SH, Pollet D, Waldmann P, Kienle C, Werner I, Haigis AC, Knapen D, Vergauwen L, Spehr M, Schulz W, Busch W, Leuthold D, Scholz S, vom Berg CM, Basu N, Murphy CA, Lampert A, Kuckelkorn J, Grummt T, Hollert H. An ecotoxicological view on neurotoxicity assessment. ENVIRONMENTAL SCIENCES EUROPE 2018; 30:46. [PMID: 30595996 PMCID: PMC6292971 DOI: 10.1186/s12302-018-0173-x] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/31/2018] [Indexed: 05/04/2023]
Abstract
The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems.
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Affiliation(s)
- J. B. Legradi
- Institute for Environmental Research, Department of Ecosystem Analysis, ABBt–Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Environment and Health, VU University, 1081 HV Amsterdam, The Netherlands
| | - C. Di Paolo
- Institute for Environmental Research, Department of Ecosystem Analysis, ABBt–Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - M. H. S. Kraak
- FAME-Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE Amsterdam, The Netherlands
| | - H. G. van der Geest
- FAME-Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE Amsterdam, The Netherlands
| | - E. L. Schymanski
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, 6 Avenue du Swing, 4367 Belvaux, Luxembourg
| | - A. J. Williams
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Dr., Research Triangle Park, NC 27711 USA
| | - M. M. L. Dingemans
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands
| | - R. Massei
- Department Effect-Directed Analysis, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig, Germany
| | - W. Brack
- Department Effect-Directed Analysis, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig, Germany
| | - X. Cousin
- Ifremer, UMR MARBEC, Laboratoire Adaptation et Adaptabilités des Animaux et des Systèmes, Route de Maguelone, 34250 Palavas-les-Flots, France
- INRA, UMR GABI, INRA, AgroParisTech, Domaine de Vilvert, Batiment 231, 78350 Jouy-en-Josas, France
| | - M.-L. Begout
- Ifremer, Laboratoire Ressources Halieutiques, Place Gaby Coll, 17137 L’Houmeau, France
| | - R. van der Oost
- Department of Technology, Research and Engineering, Waternet Institute for the Urban Water Cycle, Amsterdam, The Netherlands
| | - A. Carion
- Laboratory of Evolutionary and Adaptive Physiology, Institute of Life, Earth and Environment, University of Namur, 5000 Namur, Belgium
| | - V. Suarez-Ulloa
- Laboratory of Evolutionary and Adaptive Physiology, Institute of Life, Earth and Environment, University of Namur, 5000 Namur, Belgium
| | - F. Silvestre
- Laboratory of Evolutionary and Adaptive Physiology, Institute of Life, Earth and Environment, University of Namur, 5000 Namur, Belgium
| | - B. I. Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318 Leipzig, Germany
- Eberhard Karls University Tübingen, Environmental Toxicology, Center for Applied Geosciences, 72074 Tübingen, Germany
| | - M. Engwall
- MTM Research Centre, School of Science and Technology, Örebro University, Fakultetsgatan 1, 70182 Örebro, Sweden
| | - G. Nilén
- MTM Research Centre, School of Science and Technology, Örebro University, Fakultetsgatan 1, 70182 Örebro, Sweden
| | - S. H. Keiter
- MTM Research Centre, School of Science and Technology, Örebro University, Fakultetsgatan 1, 70182 Örebro, Sweden
| | - D. Pollet
- Faculty of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Stephanstrasse 7, 64295 Darmstadt, Germany
| | - P. Waldmann
- Faculty of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Stephanstrasse 7, 64295 Darmstadt, Germany
| | - C. Kienle
- Swiss Centre for Applied Ecotoxicology Eawag-EPFL, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - I. Werner
- Swiss Centre for Applied Ecotoxicology Eawag-EPFL, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - A.-C. Haigis
- Institute for Environmental Research, Department of Ecosystem Analysis, ABBt–Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - D. Knapen
- Zebrafishlab, Veterinary Physiology and Biochemistry, University of Antwerp, Wilrijk, Belgium
| | - L. Vergauwen
- Zebrafishlab, Veterinary Physiology and Biochemistry, University of Antwerp, Wilrijk, Belgium
| | - M. Spehr
- Institute for Biology II, Department of Chemosensation, RWTH Aachen University, Aachen, Germany
| | - W. Schulz
- Zweckverband Landeswasserversorgung, Langenau, Germany
| | - W. Busch
- Department of Bioanalytical Ecotoxicology, UFZ–Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - D. Leuthold
- Department of Bioanalytical Ecotoxicology, UFZ–Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - S. Scholz
- Department of Bioanalytical Ecotoxicology, UFZ–Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - C. M. vom Berg
- Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, Dübendorf, 8600 Switzerland
| | - N. Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Canada
| | - C. A. Murphy
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, USA
| | - A. Lampert
- Institute of Physiology (Neurophysiology), Aachen, Germany
| | - J. Kuckelkorn
- Section Toxicology of Drinking Water and Swimming Pool Water, Federal Environment Agency (UBA), Heinrich-Heine-Str. 12, 08645 Bad Elster, Germany
| | - T. Grummt
- Section Toxicology of Drinking Water and Swimming Pool Water, Federal Environment Agency (UBA), Heinrich-Heine-Str. 12, 08645 Bad Elster, Germany
| | - H. Hollert
- Institute for Environmental Research, Department of Ecosystem Analysis, ABBt–Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
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Li AA, Sheets LP, Raffaele K, Moser V, Hofstra A, Hoberman A, Makris SL, Garman R, Bolon B, Kaufmann W, Auer R, Lau E, Vidmar T, Bowers WJ. Recommendations for harmonization of data collection and analysis of developmental neurotoxicity endpoints in regulatory guideline studies: Proceedings of workshops presented at Society of Toxicology and joint Teratology Society and Neurobehavioral Teratology Society meetings. Neurotoxicol Teratol 2017; 63:24-45. [PMID: 28757310 PMCID: PMC6634984 DOI: 10.1016/j.ntt.2017.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/24/2017] [Accepted: 07/26/2017] [Indexed: 11/20/2022]
Abstract
The potential for developmental neurotoxicity (DNT) of environmental chemicals may be evaluated using specific test guidelines from the US Environmental Protection Agency or the Organisation for Economic Cooperation and Development (OECD). These guidelines generate neurobehavioral, neuropathological, and morphometric data that are evaluated by regulatory agencies globally. Data from these DNT guideline studies, or the more recent OECD extended one-generation reproductive toxicity guideline, play a pivotal role in children's health risk assessment in different world areas. Data from the same study may be interpreted differently by regulatory authorities in different countries resulting in inconsistent evaluations that may lead to inconsistencies in risk assessment decisions internationally, resulting in regional differences in public health protection or in commercial trade barriers. These issues of data interpretation and reporting are also relevant to juvenile and pre-postnatal studies conducted more routinely for pharmaceuticals and veterinary medicines. There is a need for development of recommendations geared toward the operational needs of the regulatory scientific reviewers who apply these studies in risk assessments, as well as the scientists who generate DNT data sets. The workshops summarized here draw upon the experience of the authors representing government, industry, contract research organizations, and academia to discuss the scientific issues that have emerged from diverse regulatory evaluations. Although various regulatory bodies have different risk management decisions and labeling requirements that are difficult to harmonize, the workshops provided an opportunity to work toward more harmonized scientific approaches for evaluating DNT data within the context of different regulatory frameworks. Five speakers and their coauthors with neurotoxicology, neuropathology, and regulatory toxicology expertise discussed issues of variability, data reporting and analysis, and expectations in DNT data that are encountered by regulatory authorities. In addition, principles for harmonized evaluation of data were suggested using guideline DNT data as case studies.
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Affiliation(s)
| | | | | | - Virginia Moser
- US EPA National Health and Environmental Effects Research Laboratory, Office of Research and Development (NHEERL, ORD), USA
| | | | - Alan Hoberman
- Charles River Laboratories, Global Developmental, Reproductive and Juvenile Toxicology, USA.
| | - Susan L Makris
- US EPA National Center for Environmental Assessment, Office of Research and Development (NCEA ORD), USA.
| | | | | | | | - Roland Auer
- University of Saskatchewan, Department of Pathology, Canada.
| | | | | | - Wayne J Bowers
- Department of Neuroscience, Carleton University, Ontario, Canada
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49
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Frank CL, Brown JP, Wallace K, Mundy WR, Shafer TJ. From the Cover: Developmental Neurotoxicants Disrupt Activity in Cortical Networks on Microelectrode Arrays: Results of Screening 86 Compounds During Neural Network Formation. Toxicol Sci 2017; 160:121-135. [DOI: 10.1093/toxsci/kfx169] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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50
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Tohyama C. Developmental neurotoxicity test guidelines: problems and perspectives. J Toxicol Sci 2017; 41:SP69-SP79. [PMID: 28250285 DOI: 10.2131/jts.41.sp69] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Epidemiologic evidence has demonstrated associations between early life exposure to industrial chemicals and the occurrence of disease states, including cognitive and behavioral abnormalities, in children. The developing brain in the fetal and infantile periods is extremely vulnerable to chemicals because the blood-brain barrier is not completely formed during these periods. The Organisation for Economic Co-operation and Development (OECD) developmental neurotoxicity (DNT) test guideline, TG426, updated in 2007, comprises in vivo behavioral observational tests and other tests intended to assess DNT induced by exposure to industrial chemicals. These chemicals may enter the market without having been subjected to DNT testing, as DNT test data is not mandated by law at the time of chemical registration. In addition, proprietary rights have led to problems concerning the non-disclosure of industrial chemical toxicity test data, including DNT test data. To overcome the disadvantages of high-cost and low time efficiency of in vivo DNT tests, in vitro or in silico tests are the proposed alternatives, but it is unlikely that the results of such tests would reflect changes in higher brain functions. Accordingly, the current DNT test guidelines need to be revised to avoid overlooking or neglecting the occurrence of DNT induced by exposure to low doses of chemicals. This review also proposes the introduction of novel in vivo DNT testing methods in light of a cost-performance analysis.
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Affiliation(s)
- Chiharu Tohyama
- Health, Environment, Science and Technology International Consulting (HESTIC)
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