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Choi MS, Park SM, Kim S, Jegal H, Lee HA, Han HY, Yoon S, Kim SK, Oh JH. Enhanced electrophysiological activity and neurotoxicity screening of environmental chemicals using 3D neurons from human neural precursor cells purified with PSA-NCAM. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 280:116516. [PMID: 38820819 DOI: 10.1016/j.ecoenv.2024.116516] [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: 10/23/2023] [Revised: 05/23/2024] [Accepted: 05/24/2024] [Indexed: 06/02/2024]
Abstract
The assessment of neurotoxicity for environmental chemicals is of utmost importance in ensuring public health and environmental safety. Multielectrode array (MEA) technology has emerged as a powerful tool for assessing disturbances in the electrophysiological activity. Although human embryonic stem cell (hESC)-derived neurons have been used in MEA for neurotoxicity screening, obtaining a substantial and sufficiently active population of neurons from hESCs remains challenging. In this study, we successfully differentiated neurons from a large population of human neuronal precursor cells (hNPC) purified using a polysialylated neural cell adhesion molecule (PSA-NCAM), referred to as hNPCPSA-NCAM+. The functional characterization demonstrated that hNPCPSA-NCAM+-derived neurons improve functionality by enhancing electrophysiological activity compared to total hNPC-derived neurons. Furthermore, three-dimensional (3D) neurons derived from hNPCPSA-NCAM+ exhibited reduced maturation time and enhanced electrophysiological activity on MEA. We employed subdivided population analysis of active mean firing rate (MFR) based on electrophysiological intensity to characterize the electrophysiological properties of hNPCPSA-NCAM+-3D neurons. Based on electrophysiological activity including MFR and burst parameters, we evaluated the sensitivity of hNPCPSA-NCAM+-3D neurons on MEA to screen both inhibitory and excitatory neuroactive environmental chemicals. Intriguingly, electrophysiologically active hNPCPSA-NCAM+-3D neurons demonstrated good sensitivity to evaluate neuroactive chemicals, particularly in discriminating excitatory chemicals. Our findings highlight the effectiveness of MEA approaches using hNPCPSA-NCAM+-3D neurons in the assessment of neurotoxicity associated with environmental chemicals. Furthermore, we emphasize the importance of selecting appropriate signal intensity thresholds to enhance neurotoxicity prediction and screening of environmental chemicals.
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Affiliation(s)
- Mi-Sun Choi
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea; College of Pharmacy, Chungnam National University, Daejeon, the Republic of Korea
| | - Se-Myo Park
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea
| | - Soojin Kim
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea
| | - Hyun Jegal
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea; Department of Human and Environmental Toxicology, University of Science & Technology, Daejeon, the Republic of Korea
| | - Hyang-Ae Lee
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea
| | - Hyoung-Yun Han
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea; Department of Human and Environmental Toxicology, University of Science & Technology, Daejeon, the Republic of Korea
| | - Seokjoo Yoon
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea; Department of Human and Environmental Toxicology, University of Science & Technology, Daejeon, the Republic of Korea
| | - Sang-Kyum Kim
- College of Pharmacy, Chungnam National University, Daejeon, the Republic of Korea.
| | - Jung-Hwa Oh
- Department of predictive toxicology, Korea Institute of Toxicology (KIT), Daejeon, the Republic of Korea; Department of Human and Environmental Toxicology, University of Science & Technology, Daejeon, the Republic of Korea.
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Gutsfeld S, Wehmas L, Omoyeni I, Schweiger N, Leuthold D, Michaelis P, Howey XM, Gaballah S, Herold N, Vogs C, Wood C, Bertotto L, Wu GM, Klüver N, Busch W, Scholz S, Schor J, Tal T. Investigation of Peroxisome Proliferator-Activated Receptor Genes as Requirements for Visual Startle Response Hyperactivity in Larval Zebrafish Exposed to Structurally Similar Per- and Polyfluoroalkyl Substances (PFAS). ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:77007. [PMID: 39046251 PMCID: PMC11268134 DOI: 10.1289/ehp13667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 05/31/2024] [Accepted: 06/04/2024] [Indexed: 07/25/2024]
Abstract
BACKGROUND Per- and polyfluoroalkyl Substances (PFAS) are synthetic chemicals widely detected in humans and the environment. Exposure to perfluorooctanesulfonic acid (PFOS) or perfluorohexanesulfonic acid (PFHxS) was previously shown to cause dark-phase hyperactivity in larval zebrafish. OBJECTIVES The objective of this study was to elucidate the mechanism by which PFOS or PFHxS exposure caused hyperactivity in larval zebrafish. METHODS Swimming behavior was assessed in 5-d postfertilization (dpf) larvae following developmental (1-4 dpf) or acute (5 dpf) exposure to 0.43 - 7.86 μ M PFOS, 7.87 - 120 μ M PFHxS, or 0.4% dimethyl sulfoxide (DMSO). After developmental exposure and chemical washout at 4 dpf, behavior was also assessed at 5-8 dpf. RNA sequencing was used to identify differences in global gene expression to perform transcriptomic benchmark concentration-response (BMC T ) modeling, and predict upstream regulators in PFOS- or PFHxS-exposed larvae. CRISPR/Cas9-based gene editing was used to knockdown peroxisome proliferator-activated receptors (ppars) pparaa/ab, pparda/db, or pparg at day 0. Knockdown crispants were exposed to 7.86 μ M PFOS or 0.4% DMSO from 1-4 dpf and behavior was assessed at 5 dpf. Coexposure with the ppard antagonist GSK3787 and PFOS was also performed. RESULTS Transient dark-phase hyperactivity occurred following developmental or acute exposure to PFOS or PFHxS, relative to the DMSO control. In contrast, visual startle response (VSR) hyperactivity only occurred following developmental exposure and was irreversible up to 8 dpf. Similar global transcriptomic profiles, BMC T estimates, and enriched functions were observed in PFOS- and PFHxS-exposed larvae, and ppars were identified as putative upstream regulators. Knockdown of pparda/db, but not pparaa/ab or pparg, blunted PFOS-dependent VSR hyperactivity to control levels. This finding was confirmed via antagonism of ppard in PFOS-exposed larvae. DISCUSSION This work identifies a novel adverse outcome pathway for VSR hyperactivity in larval zebrafish. We demonstrate that developmental, but not acute, exposure to PFOS triggered persistent VSR hyperactivity that required ppard function. https://doi.org/10.1289/EHP13667.
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Affiliation(s)
- Sebastian Gutsfeld
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Leah Wehmas
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Ifeoluwa Omoyeni
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Nicole Schweiger
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - David Leuthold
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Paul Michaelis
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Xia Meng Howey
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Shaza Gaballah
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Nadia Herold
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Carolina Vogs
- Department of Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Carmen Wood
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Luísa Bertotto
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Gi-Mick Wu
- Research and Development Institute for the Agri-Environment, Quebec, Quebec, Canada
| | - Nils Klüver
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Wibke Busch
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Jana Schor
- Department of Computational Biology and Chemistry, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Tamara Tal
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
- Medical Faculty, University Leipzig, Leipzig, Germany
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3
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Martin MM, Carpenter AF, Shafer TJ, Paul Friedman K, Carstens KE. Chemical effects on neural network activity: Comparison of acute versus network formation exposure in microelectrode array assays. Toxicology 2024; 505:153842. [PMID: 38788893 DOI: 10.1016/j.tox.2024.153842] [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: 03/22/2024] [Revised: 05/08/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024]
Abstract
New approach methodologies (NAMs) can address information gaps on potential neurotoxicity or developmental neurotoxicity hazard for data-poor chemicals. Two assays have been previously developed using microelectrode arrays (MEA), a technology which measures neural activity. The MEA acute network function assay (AcN) uses dissociated rat cortical cells cultured at postnatal day 0 and evaluates network activity during a 40-minute chemical exposure on day in vitro (DIV)13 or 15. In contrast, the MEA network formation assay (NFA) uses a developmental exposure paradigm spanning DIV0 through DIV12. Measures of network activity over time at DIV5, 7, 9, and 12 in the NFA are reduced to an estimated area under the curve to facilitate concentration-response evaluation. Here, we evaluated the hypothesis that chemicals with effects in the AcN also perturb the NFA by examining quantitative and qualitative concordance between assays. Out of 243 chemicals screened in both assays, we observed 70.3% concordance between the AcN and NFA after eliminating activity inferred to be cytotoxic (selective activity), with the majority of discordance explained by chemicals that altered selective activity in the AcN but not NFA. The NFA detected more active chemicals when evaluating activity associated with cytotoxicity. Median potency values were lower in the NFA compared to the AcN, but within-chemical potency values were not uniformly lower in the NFA than the AcN. Lastly, the AcN and NFA captured unique bioactivity fingerprints; the AcN was more informative for identifying chemicals with a shared mode of action, while the NFA provided information relevant to developmental exposure. Taken together, this analysis provides a rationale for using both approaches for chemical evaluation with consideration of the context of use, such as screening/ prioritization, hazard identification, or to address questions regarding biological mechanism or function.
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Affiliation(s)
- Melissa M Martin
- Computational Toxicology & Bioinformatics Branch, Biomolecular and Computational Toxicology Division, CCTE/ORD, US. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Amy F Carpenter
- Computational Toxicology & Bioinformatics Branch, Biomolecular and Computational Toxicology Division, CCTE/ORD, US. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, USA
| | - Timothy J Shafer
- Computational Toxicology & Bioinformatics Branch, Biomolecular and Computational Toxicology Division, CCTE/ORD, US. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Katie Paul Friedman
- Computational Toxicology & Bioinformatics Branch, Biomolecular and Computational Toxicology Division, CCTE/ORD, US. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Kelly E Carstens
- Computational Toxicology & Bioinformatics Branch, Biomolecular and Computational Toxicology Division, CCTE/ORD, US. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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4
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Karaboga S, Severac F, Collins EMS, Stab A, Davis A, Souchet M, Hervé G. Organophosphate toxicity patterns: A new approach for assessing organophosphate neurotoxicity. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134236. [PMID: 38613959 DOI: 10.1016/j.jhazmat.2024.134236] [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: 01/10/2024] [Revised: 03/30/2024] [Accepted: 04/06/2024] [Indexed: 04/15/2024]
Abstract
Organophosphorus compounds or organophosphates (OPs) are widely used as flame retardants, plasticizers, lubricants and pesticides. This contributes to their ubiquitous presence in the environment and to the risk of human exposure. The persistence of OPs and their bioaccumulative characteristics raise serious concerns regarding environmental and human health impacts. To address the need for safer OPs, this study uses a New Approach Method (NAM) to analyze the neurotoxicity pattern of 42 OPs. The NAM consists of a 4-step process that combines computational modeling with in vitro and in vivo experimental studies. Using spherical harmonic-based cluster analysis, the OPs were grouped into four main clusters. Experimental data and quantitative structure-activity relationships (QSARs) analysis were used in conjunction to provide information on the neurotoxicity profile of each group. Results showed that one of the identified clusters had a favorable safety profile, which may help identify safer OPs for industrial applications. In addition, the 3D-computational analysis of each cluster was used to identify meta-molecules with specific 3D features. Toxicity was found to correspond to the level of phosphate surface accessibility. Substances with conformations that minimize phosphate surface accessibility caused less neurotoxic effect. This multi-assay NAM could be used as a guide for the classification of OP toxicity, helping to minimize the health and environmental impacts of OPs, and providing rapid support to the chemical regulators, whilst reducing reliance on animal testing.
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Affiliation(s)
- Sinan Karaboga
- Harmonic Pharma, Campus Artem 92, rue du Sergent Blandan, 54000 Nancy, France
| | - Florence Severac
- R&D Laboratory and Technical Department, NYCO, 75008 Paris, France
| | | | - Aurélien Stab
- Harmonic Pharma, Campus Artem 92, rue du Sergent Blandan, 54000 Nancy, France
| | - Audrey Davis
- UniCaen, Université de Caen Normandie, Normandie, CERMN, 14000 Caen, France
| | - Michel Souchet
- Harmonic Pharma, Campus Artem 92, rue du Sergent Blandan, 54000 Nancy, France
| | - Grégoire Hervé
- R&D Laboratory and Technical Department, NYCO, 75008 Paris, France.
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5
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Silva MH. Investigating open access new approach methods (NAM) to assess biological points of departure: A case study with 4 neurotoxic pesticides. Curr Res Toxicol 2024; 6:100156. [PMID: 38404712 PMCID: PMC10891343 DOI: 10.1016/j.crtox.2024.100156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/28/2023] [Accepted: 02/09/2024] [Indexed: 02/27/2024] Open
Abstract
Open access new approach methods (NAM) in the US EPA ToxCast program and NTP Integrated Chemical Environment (ICE) were used to investigate activities of four neurotoxic pesticides: endosulfan, fipronil, propyzamide and carbaryl. Concordance of in vivo regulatory points of departure (POD) adjusted for interspecies extrapolation (AdjPOD) to modelled human Administered Equivalent Dose (AEDHuman) was assessed using 3-compartment or Adult/Fetal PBTK in vitro to in vivo extrapolation. Model inputs were from Tier 1 (High throughput transcriptomics: HTTr, high throughput phenotypic profiling: HTPP) and Tier 2 (single target: ToxCast) assays. HTTr identified gene expression signatures associated with potential neurotoxicity for endosulfan, propyzamide and carbaryl in non-neuronal MCF-7 and HepaRG cells. The HTPP assay in U-2 OS cells detected potent effects on DNA endpoints for endosulfan and carbaryl, and mitochondria with fipronil (propyzamide was inactive). The most potent ToxCast assays were concordant with specific components of each chemical mode of action (MOA). Predictive adult IVIVE models produced fold differences (FD) < 10 between the AEDHuman and the measured in vivo AdjPOD. The 3-compartment model was concordant (i.e., smallest FD) for endosulfan, fipronil and carbaryl, and PBTK was concordant for propyzamide. The most potent AEDHuman predictions for each chemical showed HTTr, HTPP and ToxCast were mainly concordant with in vivo AdjPODs but assays were less concordant with MOAs. This was likely due to the cell types used for testing and/or lack of metabolic capabilities and pathways available in vivo. The Fetal PBTK model had larger FDs than adult models and was less predictive overall.
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Brüll M, Geese N, Celardo I, Laumann M, Leist M. Preparation of Viable Human Neurites for Neurobiological and Neurodegeneration Studies. Cells 2024; 13:242. [PMID: 38334634 PMCID: PMC10854604 DOI: 10.3390/cells13030242] [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: 12/21/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024] Open
Abstract
Few models allow the study of neurite damage in the human central nervous system. We used here dopaminergic LUHMES neurons to establish a culture system that allows for (i) the observation of highly enriched neurites, (ii) the preparation of the neurite fraction for biochemical studies, and (iii) the measurement of neurite markers and metabolites after axotomy. LUHMES-based spheroids, plated in culture dishes, extended neurites of several thousand µm length, while all somata remained aggregated. These cultures allowed an easy microscopic observation of live or fixed neurites. Neurite-only cultures (NOC) were produced by cutting out the still-aggregated somata. The potential application of such cultures was exemplified by determinations of their protein and RNA contents. For instance, the mitochondrial TOM20 protein was highly abundant, while nuclear histone H3 was absent. Similarly, mitochondrial-encoded RNAs were found at relatively high levels, while the mRNA for a histone or the neuronal nuclear marker NeuN (RBFOX3) were relatively depleted in NOC. Another potential use of NOC is the study of neurite degeneration. For this purpose, an algorithm to quantify neurite integrity was developed. Using this tool, we found that the addition of nicotinamide drastically reduced neurite degeneration. Also, the chelation of Ca2+ in NOC delayed the degeneration, while inhibitors of calpains had no effect. Thus, NOC proved to be suitable for biochemical analysis and for studying degeneration processes after a defined cut injury.
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Affiliation(s)
- Markus Brüll
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Nils Geese
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Ivana Celardo
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Michael Laumann
- Electron Microscopy Centre, University of Konstanz, 78457 Konstanz, Germany;
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
- Center for Alternatives to Animal Testing in Europe (CAAT-Europe), University of Konstanz, 78457 Konstanz, Germany
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Beal MA, Chen G, Dearfield KL, Gi M, Gollapudi B, Heflich RH, Horibata K, Long AS, Lovell DP, Parsons BL, Pfuhler S, Wills J, Zeller A, Johnson G, White PA. Interpretation of in vitro concentration-response data for risk assessment and regulatory decision-making: Report from the 2022 IWGT quantitative analysis expert working group meeting. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023. [PMID: 38115239 DOI: 10.1002/em.22582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 09/15/2023] [Accepted: 12/16/2023] [Indexed: 12/21/2023]
Abstract
Quantitative risk assessments of chemicals are routinely performed using in vivo data from rodents; however, there is growing recognition that non-animal approaches can be human-relevant alternatives. There is an urgent need to build confidence in non-animal alternatives given the international support to reduce the use of animals in toxicity testing where possible. In order for scientists and risk assessors to prepare for this paradigm shift in toxicity assessment, standardization and consensus on in vitro testing strategies and data interpretation will need to be established. To address this issue, an Expert Working Group (EWG) of the 8th International Workshop on Genotoxicity Testing (IWGT) evaluated the utility of quantitative in vitro genotoxicity concentration-response data for risk assessment. The EWG first evaluated available in vitro methodologies and then examined the variability and maximal response of in vitro tests to estimate biologically relevant values for the critical effect sizes considered adverse or unacceptable. Next, the EWG reviewed the approaches and computational models employed to provide human-relevant dose context to in vitro data. Lastly, the EWG evaluated risk assessment applications for which in vitro data are ready for use and applications where further work is required. The EWG concluded that in vitro genotoxicity concentration-response data can be interpreted in a risk assessment context. However, prior to routine use in regulatory settings, further research will be required to address the remaining uncertainties and limitations.
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Affiliation(s)
- Marc A Beal
- Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Guangchao Chen
- Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Utrecht, the Netherlands
| | - Kerry L Dearfield
- Retired from US Environmental Protection Agency and US Department of Agriculture, Washington, DC, USA
| | - Min Gi
- Department of Environmental Risk Assessment, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | | | - Robert H Heflich
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Katsuyoshi Horibata
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Kawasaki, Kanagawa, Japan
| | - Alexandra S Long
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - David P Lovell
- St George's Medical School, University of London, London, UK
| | - Barbara L Parsons
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Stefan Pfuhler
- Global Product Stewardship - Human Safety, Procter & Gamble, Cincinnati, Ohio, USA
| | - John Wills
- Genetic Toxicology and Photosafety, GSK Research & Development, Stevenage, UK
| | - Andreas Zeller
- Pharmaceutical Sciences, pRED Innovation Center Basel, Hoffmann-La Roche Ltd, Basel, Switzerland
| | - George Johnson
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Paul A White
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
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8
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Pitzer EM, Shafer TJ, Herr DW. Identification of neurotoxicology (NT)/developmental neurotoxicology (DNT) adverse outcome pathways and key event linkages with in vitro DNT screening assays. Neurotoxicology 2023; 99:184-194. [PMID: 37866692 DOI: 10.1016/j.neuro.2023.10.007] [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: 04/14/2023] [Revised: 08/14/2023] [Accepted: 10/13/2023] [Indexed: 10/24/2023]
Abstract
There is a need to assess compounds reliably and quickly for neurotoxicity (NT) and developmental neurotoxicity (DNT). Adverse outcome pathways (AOPs) enable the mapping of molecular events to an apical endpoint in a chemical agnostic manner and have begun to be applied in NT and DNT testing frameworks. We assessed the status of NT/DNT AOPs in the AOP-Wiki (ca. 2/1/23; https://aopwiki.org/), to characterize the state of AOP development, identify strengths and knowledge gaps, elucidate areas for improvement, and describe areas for future focus. AOPs in the Wiki database were assessed for inclusion of NT/DNT molecular events and endpoints, AOP development and endorsement, as well as the linkages of key neurodevelopmental processes with in vitro new approach methods (NAMs). This review found that 41 AOPs have been proposed detailing NT/DNT, of which eight were endorsed by working parties in OECD. Further, this review determined that learning and memory is included as an adverse outcome in eight NT/DNT AOPS, often without distinction regarding the varying forms of learning and memory, regional specification, temporal dynamics, or acquisition mechanisms involved. There is also an overlap with key events (KEs) and in vitro NAMs, which synaptogenesis appeared as a common process. Overall, progress on NT/DNT AOPs could be expanded, adding in modes of action that are missing, improvement in defining apical endpoints, as well as utilizing NAMs further to develop AOPs and identify gaps in current knowledge.
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Affiliation(s)
- Emily M Pitzer
- Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Timothy J Shafer
- Center for Computational Toxicology and Exposure, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - David W Herr
- Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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9
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Kreutz A, Hu G, Tokar E. Pluripotent Stem Cell-derived Dopaminergic Neurons for Studying Developmental Neurotoxicity. Stem Cell Rev Rep 2023; 19:2120-2130. [PMID: 37273171 PMCID: PMC10579108 DOI: 10.1007/s12015-023-10555-9] [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] [Accepted: 05/08/2023] [Indexed: 06/06/2023]
Abstract
With the vast number of chemicals in commerce, higher throughput strategies are needed to inform risk assessment. The field of toxicology is therefore moving away from traditional in vivo guideline studies towards in vitro new approach methodologies. There has been a great push for such a shift in the field of developmental neurotoxicity, where there is a particular lack of data. A battery of in vitro new approach methodologies has thus been developed to help fill this gap. Included in this battery are assays for numerous processes critical to neurodevelopment, such as proliferation, migration, and synaptogenesis. The current battery of developmental neurotoxicity new approach methodologies still lacks recapitulation of several critical neurodevelopmental processes, including development of neuronal subtypes. With their pluripotency, alongside other advantages, pluripotent stem cells (PSCs) are uniquely suited to address questions of developmental neurotoxicity, as they can recapitulate the different stages of human in vivo neurodevelopment. Among the various neuronal subtypes, development of dopaminergic neurons (DA) is perhaps the best understood and several approaches exist to differentiate PSCs into DA. Herein we review these approaches and propose utilizing PSCs for screening of the impact of environmental chemicals on development of DA. Related techniques and gaps in knowledge are also addressed.
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Affiliation(s)
- Anna Kreutz
- Mechanistic Toxicology Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, Durham, NC, 27709, USA.
- Epigenetics and Stem Cell Biology Laboratory, Division of Intramural Research, NIEHS, Research Triangle Park, Durham, NC, 27709, USA.
| | - Guang Hu
- Epigenetics and Stem Cell Biology Laboratory, Division of Intramural Research, NIEHS, Research Triangle Park, Durham, NC, 27709, USA
| | - Erik Tokar
- Mechanistic Toxicology Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, Durham, NC, 27709, USA
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Feshuk M, Kolaczkowski L, Dunham K, Davidson-Fritz SE, Carstens KE, Brown J, Judson RS, Paul Friedman K. The ToxCast pipeline: updates to curve-fitting approaches and database structure. FRONTIERS IN TOXICOLOGY 2023; 5:1275980. [PMID: 37808181 PMCID: PMC10552852 DOI: 10.3389/ftox.2023.1275980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 09/08/2023] [Indexed: 10/10/2023] Open
Abstract
Introduction: The US Environmental Protection Agency Toxicity Forecaster (ToxCast) program makes in vitro medium- and high-throughput screening assay data publicly available for prioritization and hazard characterization of thousands of chemicals. The assays employ a variety of technologies to evaluate the effects of chemical exposure on diverse biological targets, from distinct proteins to more complex cellular processes like mitochondrial toxicity, nuclear receptor signaling, immune responses, and developmental toxicity. The ToxCast data pipeline (tcpl) is an open-source R package that stores, manages, curve-fits, and visualizes ToxCast data and populates the linked MySQL Database, invitrodb. Methods: Herein we describe major updates to tcpl and invitrodb to accommodate a new curve-fitting approach. The original tcpl curve-fitting models (constant, Hill, and gain-loss models) have been expanded to include Polynomial 1 (Linear), Polynomial 2 (Quadratic), Power, Exponential 2, Exponential 3, Exponential 4, and Exponential 5 based on BMDExpress and encoded by the R package dependency, tcplfit2. Inclusion of these models impacted invitrodb (beta version v4.0) and tcpl v3 in several ways: (1) long-format storage of generic modeling parameters to permit additional curve-fitting models; (2) updated logic for winning model selection; (3) continuous hit calling logic; and (4) removal of redundant endpoints as a result of bidirectional fitting. Results and discussion: Overall, the hit call and potency estimates were largely consistent between invitrodb v3.5 and 4.0. Tcpl and invitrodb provide a standard for consistent and reproducible curve-fitting and data management for diverse, targeted in vitro assay data with readily available documentation, thus enabling sharing and use of these data in myriad toxicology applications. The software and database updates described herein promote comparability across multiple tiers of data within the US Environmental Protection Agency CompTox Blueprint.
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Affiliation(s)
- M. Feshuk
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
| | - L. Kolaczkowski
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
- National Student Services Contractor, Oak Ridge Associated Universities, Oak Ridge, TN, United States
| | - K. Dunham
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
- National Student Services Contractor, Oak Ridge Associated Universities, Oak Ridge, TN, United States
| | - S. E. Davidson-Fritz
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
| | - K. E. Carstens
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
| | - J. Brown
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
| | - R. S. Judson
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
| | - K. Paul Friedman
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States
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11
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Lemée P, Fessard V, Habauzit D. Prioritization of mycotoxins based on mutagenicity and carcinogenicity evaluation using combined in silico QSAR methods. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121284. [PMID: 36804886 DOI: 10.1016/j.envpol.2023.121284] [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: 09/26/2022] [Revised: 02/01/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
Mycotoxins and their metabolites are a family of compounds that contains a great diversity of both structure and biological properties. Information on their toxicity is spread within several databases and in scientific literature. Due to the number of molecules and their structure diversity, the cost and time required for hazard evaluation of each compound is unrealistic. In that purpose, new approach methodologies (NAMs) can be applied to evaluate such large set of molecules. Among them, quantitative structure-activity relationship (QSAR) in silico models could be useful to predict the mutagenic and carcinogenic properties of mycotoxins. First, a complete list of 904 mycotoxins and metabolites was built. Then, some known mycotoxins were used to determine the best QSAR tools for mutagenicity and carcinogenicity predictions. The best tool was further applied to the whole list of 904 mycotoxins. At the end, 95 mycotoxins were identified as both mutagen and carcinogen and should be prioritized for further evaluation.
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Affiliation(s)
- Pierre Lemée
- ANSES (French Agency for Food, Environmental and Occupational Health & Safety), Toxicology of Contaminants Unit, Fougères, France
| | - Valérie Fessard
- ANSES (French Agency for Food, Environmental and Occupational Health & Safety), Toxicology of Contaminants Unit, Fougères, France
| | - Denis Habauzit
- ANSES (French Agency for Food, Environmental and Occupational Health & Safety), Toxicology of Contaminants Unit, Fougères, France.
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12
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Carstens KE, Freudenrich T, Wallace K, Choo S, Carpenter A, Smeltz M, Clifton MS, Henderson WM, Richard AM, Patlewicz G, Wetmore BA, Paul Friedman K, Shafer T. Evaluation of Per- and Polyfluoroalkyl Substances (PFAS) In Vitro Toxicity Testing for Developmental Neurotoxicity. Chem Res Toxicol 2023; 36:402-419. [PMID: 36821828 PMCID: PMC10249374 DOI: 10.1021/acs.chemrestox.2c00344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a diverse set of commercial chemicals widely detected in humans and the environment. However, only a limited number of PFAS are associated with epidemiological or experimental data for hazard identification. To provide developmental neurotoxicity (DNT) hazard information, the work herein employed DNT new approach methods (NAMs) to generate in vitro screening data for a set of 160 PFAS. The DNT NAMs battery was comprised of the microelectrode array neuronal network formation assay (NFA) and high-content imaging (HCI) assays to evaluate proliferation, apoptosis, and neurite outgrowth. The majority of PFAS (118/160) were inactive or equivocal in the DNT NAMs, leaving 42 active PFAS that decreased measures of neural network connectivity and neurite length. Analytical quality control indicated 43/118 inactive PFAS samples and 10/42 active PFAS samples were degraded; as such, careful interpretation is required as some negatives may have been due to loss of the parent PFAS, and some actives may have resulted from a mixture of parent and/or degradants of PFAS. PFAS containing a perfluorinated carbon (C) chain length ≥8, a high C:fluorine ratio, or a carboxylic acid moiety were more likely to be bioactive in the DNT NAMs. Of the PFAS positives in DNT NAMs, 85% were also active in other EPA ToxCast assays, whereas 79% of PFAS inactives in the DNT NAMs were active in other assays. These data demonstrate that a subset of PFAS perturb neurodevelopmental processes in vitro and suggest focusing future studies of DNT on PFAS with certain structural feature descriptors.
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Affiliation(s)
- Kelly E Carstens
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Theresa Freudenrich
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Kathleen Wallace
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Seline Choo
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee 37830, United States
| | - Amy Carpenter
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee 37830, United States
| | - Marci Smeltz
- Center for Environmental Measurement and Modeling, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Matthew S Clifton
- Center for Environmental Measurement and Modeling, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - W Matthew Henderson
- Center for Environmental Measurement and Modeling, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Ann M Richard
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Grace Patlewicz
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Katie Paul Friedman
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Timothy Shafer
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
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13
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Silva M, Kwok RKH. Use of computational toxicology models to predict toxicological points of departure: A case study with triazine herbicides. Birth Defects Res 2023; 115:525-544. [PMID: 36584090 DOI: 10.1002/bdr2.2144] [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: 07/22/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND Atrazine simazine and propazine, widely used triazine herbicides on food crops and in residential areas, disrupt the neuroendocrine system raising human health concerns. USEPA developed a PBPK model based on triazine common Mode of Action (MOA)-suppression of luteinizing hormone surge in female rats-to generate human regulatory points of departure (POD: mg/kg/day). We compared triazine Human Administered Equivalent Dose (AEDHuman mg/kg/day) predictions from open access computational tools to the PBPK PODs to assess concordance. METHODS Computational tools were the following: ToxCast/Tox21 in vitro assays; Toxicogenomic databases to assess concordance with ToxCast/Tox21 targets; integrated chemical environment (ICE) models with ToxCast/Tox21 inputs to predict AEDHuman PODs and population-based age-refined high throughput toxicokinetics (HTTK-Pop) to compare to age-related PBPK PODs. RESULTS ToxCast/Tox21 assays identified critical targets in the triazine common MOA and gene databases; ICE AEDHuman predictions were mainly concordant with the USEPA PBPK PODs quantitatively. Low fold-differences between PBPK POD and ICE AEDHuman predictions indicated that the ICE models are health-protective. HTTK-Pop age-refinements were within 10-fold of the USEPA PBPK PODs. CONCLUSIONS CompTox tools were used to identify assay targets in the MOA and identify potential molecular initiating targets in the adverse outcome pathway for potential use in risk assessment.
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Affiliation(s)
- Marilyn Silva
- Retired from the California Environmental Protection Agency, Sacramento, California, USA
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14
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Cervetto C, Pistollato F, Amato S, Mendoza-de Gyves E, Bal-Price A, Maura G, Marcoli M. Assessment of neurotransmitter release in human iPSC-derived neuronal/glial cells: a missing in vitro assay for regulatory developmental neurotoxicity testing. Reprod Toxicol 2023; 117:108358. [PMID: 36863571 PMCID: PMC10112275 DOI: 10.1016/j.reprotox.2023.108358] [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: 11/18/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/04/2023]
Abstract
Human induced pluripotent stem cell (hiPSC)-derived neural stem cells (NSCs) and their differentiated neuronal/glial derivatives have been recently considered suitable to assess in vitro developmental neurotoxicity (DNT) triggered by exposure to environmental chemicals. The use of human-relevant test systems combined with in vitro assays specific for different neurodevelopmental events, enables a mechanistic understanding of the possible impact of environmental chemicals on the developing brain, avoiding extrapolation uncertainties associated with in vivo studies. Currently proposed in vitro battery for regulatory DNT testing accounts for several assays suitable to study key neurodevelopmental processes, including NSC proliferation and apoptosis, differentiation into neurons and glia, neuronal migration, synaptogenesis, and neuronal network formation. However, assays suitable to measure interference of compounds with neurotransmitter release or clearance are at present not included, which represents a clear gap of the biological applicability domain of such a testing battery. Here we applied a HPLC-based methodology to measure the release of neurotransmitters in a previously characterized hiPSC-derived NSC model undergoing differentiation towards neurons and glia. Glutamate release was assessed in control cultures and upon depolarization, as well as in cultures repeatedly exposed to some known neurotoxicants (BDE47 and lead) and chemical mixtures. Obtained data indicate that these cells have the ability to release glutamate in a vesicular manner, and that both glutamate clearance and vesicular release concur in the maintenance of extracellular glutamate levels. In conclusion, analysis of neurotransmitter release is a sensitive readout that should be included in the envisioned battery of in vitro assays for DNT testing.
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Affiliation(s)
- Chiara Cervetto
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy; Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Centro 3R, Pisa, Italy.
| | | | - Sarah Amato
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy
| | | | - Anna Bal-Price
- European Commission, Joint Research Centre, JRC, Ispra, Italy.
| | - Guido Maura
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy
| | - Manuela Marcoli
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy; Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Centro 3R, Pisa, Italy.
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15
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Adedara IA, Mohammed KA, Canzian J, Rosemberg DB, Aschner M, Farombi EO, Rocha JB. Nauphoeta cinerea as an emerging model in neurotoxicology. ADVANCES IN NEUROTOXICOLOGY 2023; 9:181-196. [PMID: 37389201 PMCID: PMC10310038 DOI: 10.1016/bs.ant.2023.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Affiliation(s)
- Isaac A. Adedara
- Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Khadija A. Mohammed
- Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Julia Canzian
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Denis B. Rosemberg
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Ebenezer O. Farombi
- Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Joao Batista Rocha
- Department of Biochemical and Molecular Biology, Federal University of Santa Maria, Santa Maria, Brazil
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16
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Braun G, Escher BI. Prioritization of mixtures of neurotoxic chemicals for biomonitoring using high-throughput toxicokinetics and mixture toxicity modeling. ENVIRONMENT INTERNATIONAL 2023; 171:107680. [PMID: 36502700 DOI: 10.1016/j.envint.2022.107680] [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: 07/29/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Modern society continues to pollute the environment with larger quantities of chemicals that have also become more structurally and functionally diverse. Risk assessment of chemicals can hardly keep up with the sheer numbers that lead to complex mixtures of increasing chemical diversity including new chemicals, substitution products on top of still abundant legacy compounds. Fortunately, over the last years computational tools have helped us to identify and prioritize chemicals of concern. These include toxicokinetic models to predict exposure to chemicals as well as new approach methodologies such as in-vitro bioassays to address toxicodynamic effects. Combined, they allow for a prediction of mixtures and their respective effects and help overcome the lack of data we face for many chemicals. In this study we propose a high-throughput approach using experimental and predicted exposure, toxicokinetic and toxicodynamic data to simulate mixtures, to which a virtual population is exposed to and predict their mixture effects. The general workflow is adaptable for any type of toxicity, but we demonstrated its applicability with a case study on neurotoxicity. If no experimental data for neurotoxicity were available, we used baseline toxicity predictions as a surrogate. Baseline toxicity is the minimal toxicity any chemical has and might underestimate the true contribution to the mixture effect but many neurotoxicants are not by orders of magnitude more potent than baseline toxicity. Therefore, including baseline-toxic effects in mixture simulations yields a more realistic picture than excluding them in mixture simulations. This workflow did not only correctly identify and prioritize known chemicals of concern like benzothiazoles, organochlorine pesticides and plasticizers but we were also able to identify new potential neurotoxicants that we recommend to include in future biomonitoring studies and if found in humans, to also include in neurotoxicity screening.
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Affiliation(s)
- Georg Braun
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
| | - Beate I Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany; Environmental Toxicology, Department of Geosciences, Eberhard Karls University Tübingen, Tübingen, Germany
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17
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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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18
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Ishida K, Tatsumi K, Minamigawa Y, Mori K, Matsumaru D, Nagase H, Kanda Y, Takuma K, Nakanishi T. Neuronal differentiation reporter mice as a new methodology for detecting in vivo developmental neurotoxicity. Biochem Pharmacol 2022; 206:115332. [PMID: 36323391 DOI: 10.1016/j.bcp.2022.115332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/18/2022]
Abstract
Current in vivo developmental neurotoxicity (DNT) tests are not performed routinely for chemical risk assessment because they are time and resource intensive and require many animals. Therefore, new methodologies are required that can detect and evaluate the DNT potential of chemicals in a more simple, quantitative, and objective manner. Toward this end, we generated transgenic mice expressing reporter genes (luciferase and lacZ) under the control of the rat synapsin 1 promoter (Syn-Rep mice) and evaluated their usefulness as a DNT detection tool. Brain luciferase expression levels in Syn-Rep mice increased dramatically from just before to after birth, peaked early in the postnatal period, subsequently decreased sharply, and then remained low after weaning. This pattern is analogous to the generally recognized temporal changes in synapse numbers in the developing mammal brain. To evaluate further the responsiveness of Syn-Rep mice during DNT induction, we administered valproic acid (VPA), a reference DNT-inducing chemical, to pregnant mice and evaluated its effect on reporter gene expression in the developing brains of Syn-Rep pups. In vivo luminescence in the brains of VPA-exposed pups was significantly lower than in controls from postnatal days 4 to 13. Moreover, luciferase activity in the prefrontal cortexes of 8-week-old VPA-exposed offspring was significantly lower than in controls, reflecting the reduced number of neurons in the prefrontal cortex. These results suggest that the Syn-Rep mice are potentially useful tools for streamlined detection of chemical-induced DNT in the developing mammalian brain.
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Affiliation(s)
- Keishi Ishida
- Laboratory of Hygienic Chemistry and Molecular Toxicology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan
| | - Kanoko Tatsumi
- Laboratory of Hygienic Chemistry and Molecular Toxicology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan
| | - Yoshiki Minamigawa
- Laboratory of Hygienic Chemistry and Molecular Toxicology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan
| | - Kazuma Mori
- Laboratory of Hygienic Chemistry and Molecular Toxicology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan
| | - Daisuke Matsumaru
- Laboratory of Hygienic Chemistry and Molecular Toxicology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan
| | - Hisamitsu Nagase
- Faculty of Pharmaceutical Sciences, Gifu University of Medical Science, 4-3-3 Nijigaoka, Kani, Gifu 509-0293, Japan
| | - Yasunari Kanda
- Division of Pharmacology, National Institute of Health Sciences, Kanagawa 210-9501, Japan
| | - Kazuhiro Takuma
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tsuyoshi Nakanishi
- Laboratory of Hygienic Chemistry and Molecular Toxicology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan.
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19
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Jarema KA, Hunter DL, Hill BN, Olin JK, Britton KN, Waalkes MR, Padilla S. Developmental Neurotoxicity and Behavioral Screening in Larval Zebrafish with a Comparison to Other Published Results. TOXICS 2022; 10:toxics10050256. [PMID: 35622669 PMCID: PMC9145655 DOI: 10.3390/toxics10050256] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/29/2022] [Accepted: 05/07/2022] [Indexed: 02/04/2023]
Abstract
With the abundance of chemicals in the environment that could potentially cause neurodevelopmental deficits, there is a need for rapid testing and chemical screening assays. This study evaluated the developmental toxicity and behavioral effects of 61 chemicals in zebrafish (Danio rerio) larvae using a behavioral Light/Dark assay. Larvae (n = 16–24 per concentration) were exposed to each chemical (0.0001–120 μM) during development and locomotor activity was assessed. Approximately half of the chemicals (n = 30) did not show any gross developmental toxicity (i.e., mortality, dysmorphology or non-hatching) at the highest concentration tested. Twelve of the 31 chemicals that did elicit developmental toxicity were toxic at the highest concentration only, and thirteen chemicals were developmentally toxic at concentrations of 10 µM or lower. Eleven chemicals caused behavioral effects; four chemicals (6-aminonicotinamide, cyclophosphamide, paraquat, phenobarbital) altered behavior in the absence of developmental toxicity. In addition to screening a library of chemicals for developmental neurotoxicity, we also compared our findings with previously published results for those chemicals. Our comparison revealed a general lack of standardized reporting of experimental details, and it also helped identify some chemicals that appear to be consistent positives and negatives across multiple laboratories.
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Affiliation(s)
- Kimberly A. Jarema
- Center for Public Health and Environmental Assessment, Immediate Office, Program Operations Staff, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
- Correspondence: (K.A.J.); (S.P.); Tel.: +1-919-541-2299 (K.A.J.); +1-919-541-3956 (S.P.)
| | - Deborah L. Hunter
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (D.L.H.); (J.K.O.)
| | - Bridgett N. Hill
- ORISE Research Participation Program Hosted by EPA, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA;
| | - Jeanene K. Olin
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (D.L.H.); (J.K.O.)
| | - Katy N. Britton
- ORAU Research Participation Program Hosted by EPA, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA;
| | - Matthew R. Waalkes
- ORISE Research Participation Program Hosted by EPA, National Health and Environmental Effects Research Laboratory, Integrated Systems Toxicology Division, Genetic and Cellular Toxicology Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA;
| | - Stephanie Padilla
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (D.L.H.); (J.K.O.)
- Correspondence: (K.A.J.); (S.P.); Tel.: +1-919-541-2299 (K.A.J.); +1-919-541-3956 (S.P.)
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20
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Dobreniecki S, Mendez E, Lowit A, Freudenrich TM, Wallace K, Carpenter A, Wetmore BA, Kreutz A, Korol-Bexell E, Friedman KP, Shafer TJ. Integration of toxicodynamic and toxicokinetic new approach methods into a weight-of-evidence analysis for pesticide developmental neurotoxicity assessment: A case-study with DL- and L-glufosinate. Regul Toxicol Pharmacol 2022; 131:105167. [PMID: 35413399 DOI: 10.1016/j.yrtph.2022.105167] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/14/2022] [Accepted: 04/06/2022] [Indexed: 01/13/2023]
Abstract
DL-glufosinate ammonium (DL-GLF) is a registered herbicide for which a guideline Developmental Neurotoxicity (DNT) study has been conducted. Offspring effects included altered brain morphometrics, decreased body weight, and increased motor activity. Guideline DNT studies are not available for its enriched isomers L-GLF acid and L-GLF ammonium; conducting one would be time consuming, resource-intensive, and possibly redundant given the existing DL-GLF DNT. To support deciding whether to request a guideline DNT study for the L-GLF isomers, DL-GLF and the L-GLF isomers were screened using in vitro assays for network formation and neurite outgrowth. DL-GLF and L-GLF isomers were without effects in both assays. DL-GLF and L-GLF (1-100 μM) isomers increased mean firing rate of mature networks to 120-140% of baseline. In vitro toxicokinetic assessments were used to derive administered equivalent doses (AEDs) for the in vitro testing concentrations. The AED for L-GLF was ∼3X higher than the NOAEL from the DL-GLF DNT indicating that the available guideline study would be protective of potential DNT due to L-GLF exposure. Based in part on the results of these in vitro studies, EPA is not requiring L-GLF isomer guideline DNT studies, thereby providing a case study for a useful application of DNT screening assays.
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Affiliation(s)
| | | | - Anna Lowit
- Office of Pesticide Programs USEPA, Washington, DC, USA
| | - Theresa M Freudenrich
- Center for Computational Toxicology and Exposure, Office of Research and Development. US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Kathleen Wallace
- Center for Computational Toxicology and Exposure, Office of Research and Development. US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Amy Carpenter
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, USA
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, Office of Research and Development. US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Anna Kreutz
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, USA
| | | | - Katie Paul Friedman
- Center for Computational Toxicology and Exposure, Office of Research and Development. US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Timothy J Shafer
- Center for Computational Toxicology and Exposure, Office of Research and Development. US Environmental Protection Agency, Research Triangle Park, NC, USA.
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