1
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Wegner S, Workman T, Park JJ, Harris S, Wallace J, Stanaway I, Hong S, Hansen B, Griffith WC, Faustman EM. A Dynamic In vitro developing testis model reflects structures and functions of testicular development in vivo. Reprod Toxicol 2023; 118:108362. [PMID: 37011698 DOI: 10.1016/j.reprotox.2023.108362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/03/2023] [Accepted: 03/14/2023] [Indexed: 04/03/2023]
Abstract
To better define appropriate applications of our 3-dimensional testicular co-culture as a model for reproductive toxicology, we evaluated the ability of the model to capture structural and functional elements that can be targeted by reproductive toxicants. Testicular co-cultures were prepared from postnatal day 5 male rats and cultured with a Matrigel overlay. Following a 2-day acclimation period, we characterized functional pathway dynamics by evaluating morphology, protein expression, testosterone concentrations, and global gene expression at a range of timepoints from experimental days 0 to 21. Western blotting confirmed expression of Sertoli cell, Leydig cell, and spermatogonial cell-specific protein markers. Testosterone detected in cell culture media indicates active testosterone production. Quantitative pathway analysis identified Gene Ontology biological processes enriched among genes significantly changing over the course of 21 days. Processes enriched among genes significantly increasing through time include general developmental processes (morphogenesis, tissue remodeling, etc.), steroid regulation, Sertoli cell development, immune response, and stress and apoptosis. Processes enriched among genes significantly decreasing over time include several related to male reproductive development (seminiferous tubule development, male gonad development, Leydig cell differentiation, Sertoli cell differentiation), all of which appear to peak in expression between days 1 and 5 before decreasing at later timepoints. This analysis provides a temporal roadmap for specific biological process of interest for reproductive toxicology in the model and anchors the model to sensitive phases of in vivo development, helping to define the relevance of the model for in vivo processes.
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Affiliation(s)
- Susanna Wegner
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Tomomi Workman
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Julie Juyoung Park
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Sean Harris
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - James Wallace
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Ian Stanaway
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Sungwoo Hong
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Brad Hansen
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - William C Griffith
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA
| | - Elaine M Faustman
- Institute for Risk Analysis and Risk Communication, University of Washington School of Public Health, Seattle, WA, USA.
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2
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Bose R, Spulber S, Ceccatelli S. The Threat Posed by Environmental Contaminants on Neurodevelopment: What Can We Learn from Neural Stem Cells? Int J Mol Sci 2023; 24:ijms24054338. [PMID: 36901772 PMCID: PMC10002364 DOI: 10.3390/ijms24054338] [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: 01/08/2023] [Revised: 02/03/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Exposure to chemicals may pose a greater risk to vulnerable groups, including pregnant women, fetuses, and children, that may lead to diseases linked to the toxicants' target organs. Among chemical contaminants, methylmercury (MeHg), present in aquatic food, is one of the most harmful to the developing nervous system depending on time and level of exposure. Moreover, certain man-made PFAS, such as PFOS and PFOA, used in commercial and industrial products including liquid repellants for paper, packaging, textile, leather, and carpets, are developmental neurotoxicants. There is vast knowledge about the detrimental neurotoxic effects induced by high levels of exposure to these chemicals. Less is known about the consequences that low-level exposures may have on neurodevelopment, although an increasing number of studies link neurotoxic chemical exposures to neurodevelopmental disorders. Still, the mechanisms of toxicity are not identified. Here we review in vitro mechanistic studies using neural stem cells (NSCs) from rodents and humans to dissect the cellular and molecular processes changed by exposure to environmentally relevant levels of MeHg or PFOS/PFOA. All studies show that even low concentrations dysregulate critical neurodevelopmental steps supporting the idea that neurotoxic chemicals may play a role in the onset of neurodevelopmental disorders.
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3
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Yazdian-Robati R, Tarhriz V, Ranjbaran H, Karimi N, Abasi M. Efficient Neural Differentiation of Mouse Embryonic Stem Cells by Mastic Gum. Biopreserv Biobank 2023; 21:38-45. [PMID: 35446125 DOI: 10.1089/bio.2021.0130] [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: 11/13/2022] Open
Abstract
Purpose: Promoting neurogenesis is a promising strategy to treat neurodegenerative disorders. In the present study, we aimed to evaluate the effect of mastic gum resin from the Pistacia lentiscus var. Chia (Anacardiaceae family) in proliferation capacity and differentiation of embryonic mesenchymal stem cells into a neural lineage. Methods: For this purpose, mastic gum was applied as a neural inducer for stem cell differentiation into the neuronal lineage. Following treatment of embryonic stem cells (ESCs) with mastic gum, verification differentiation of the ESCs into the neuronal lineage, gene expression analysis, and immunocytochemistry staining approach were performed. Results: Gene expression analysis demonstrated that mastic gum increased the expression level of neuron markers in the ESCs-derived neuron-like cells. Moreover, our immunocytochemistry staining results of two important neural stem cell markers, including Nestin and microtubule-associated protein-2 (Map2) expression confirmed that mastic gum has the potential to promote neuronal differentiation in ESCs. Conclusion: In summary, the use of mastic gum to stimulate the differentiation of ESCs into a neural lineage can be considered as a good candidate in stem cell therapy.
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Affiliation(s)
- Rezvan Yazdian-Robati
- Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Vahideh Tarhriz
- Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Ranjbaran
- Immunogenetics Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Narges Karimi
- Immunogenetics Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mozhgan Abasi
- Immunogenetics Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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4
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Piersma AH, Baker NC, Daston GP, Flick B, Fujiwara M, Knudsen TB, Spielmann H, Suzuki N, Tsaioun K, Kojima H. Pluripotent stem cell assays: Modalities and applications for predictive developmental toxicity. Curr Res Toxicol 2022; 3:100074. [PMID: 35633891 PMCID: PMC9130094 DOI: 10.1016/j.crtox.2022.100074] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/21/2022] [Accepted: 05/09/2022] [Indexed: 12/02/2022] Open
Abstract
This manuscript provides a review focused on embryonic stem cell-based models and their place within the landscape of alternative developmental toxicity assays. Against the background of the principles of developmental toxicology, the wide diversity of alternative methods using pluripotent stem cells developed in this area over the past half century is reviewed. In order to provide an overview of available models, a systematic scoping review was conducted following a published protocol with inclusion criteria, which were applied to select the assays. Critical aspects including biological domain, readout endpoint, availability of standardized protocols, chemical domain, reproducibility and predictive power of each assay are described in detail, in order to review the applicability and limitations of the platform in general and progress moving forward to implementation. The horizon of innovative routes of promoting regulatory implementation of alternative methods is scanned, and recommendations for further work are given.
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Affiliation(s)
- Aldert H. Piersma
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | | | - George P. Daston
- Global Product Stewardship, The Procter & Gamble Company, Cincinnati, OH, USA
| | - Burkhard Flick
- Experimental Toxicology and Ecology, BASF SE, Ludwigshafen am Rhein, Germany
| | - Michio Fujiwara
- Drug Safety Research Labs, Astellas Pharma Inc., Tsukuba-shi, Japan
| | - Thomas B. Knudsen
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, USA
| | - Horst Spielmann
- Institute for Pharmacy, Faculty of Biology, Chemistry, and Pharmacy, Freie Universität, Berlin, Germany
| | - Noriyuki Suzuki
- Cell Science Group Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., Osaka, Japan
| | - Katya Tsaioun
- Evidence-Based Toxicology Collaboration at Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Hajime Kojima
- National Institute of Health Sciences, Kawasaki, Japan
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5
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Abbott LC, Nigussie F. Mercury Toxicity and Neurogenesis in the Mammalian Brain. Int J Mol Sci 2021; 22:ijms22147520. [PMID: 34299140 PMCID: PMC8305137 DOI: 10.3390/ijms22147520] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/12/2021] [Accepted: 07/05/2021] [Indexed: 01/21/2023] Open
Abstract
The mammalian brain is formed from billions of cells that include a wide array of neuronal and glial subtypes. Neural progenitor cells give rise to the vast majority of these cells during embryonic, fetal, and early postnatal developmental periods. The process of embryonic neurogenesis includes proliferation, differentiation, migration, the programmed death of some newly formed cells, and the final integration of differentiated neurons into neural networks. Adult neurogenesis also occurs in the mammalian brain, but adult neurogenesis is beyond the scope of this review. Developing embryonic neurons are particularly susceptible to neurotoxicants and especially mercury toxicity. This review focused on observations concerning how mercury, and in particular, methylmercury, affects neurogenesis in the developing mammalian brain. We summarized information on models used to study developmental mercury toxicity, theories of pathogenesis, and treatments that could be used to reduce the toxic effects of mercury on developing neurons.
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Affiliation(s)
- Louise C. Abbott
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4458 TAMU, College Station, TX 77843-4458, USA
- Correspondence: ; Tel.: +1-541-254-0779
| | - Fikru Nigussie
- College of Veterinary Medicine, Oregon State University, 700 SW 30th Street, Corvallis, OR 97331, USA;
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6
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de Leeuw VC, Pennings JLA, Hessel EVS, Piersma AH. Exploring the biological domain of the neural embryonic stem cell test (ESTn): Morphogenetic regulators, Hox genes and cell types, and their usefulness as biomarkers for embryotoxicity screening. Toxicology 2021; 454:152735. [PMID: 33636252 DOI: 10.1016/j.tox.2021.152735] [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: 10/27/2020] [Revised: 01/25/2021] [Accepted: 02/20/2021] [Indexed: 11/25/2022]
Abstract
Animal-free assessment of compound-induced developmental neurotoxicity will most likely be based on batteries of multiple in vitro tests. The optimal battery is built by combining tests with complementary biological domains that together ideally cover all relevant toxicity pathways. Thus, biological domain definition, i.e. which biological processes and cell types are represented, is an important assay characteristic for determining the place of assays in testing strategies. The murine neural embryonic stem cell test (ESTn) is employed to predict the developmental neurotoxicity of compounds. The aim of this study was to explore the biological domain of ESTn according to three groups of biomarker genes of early (neuro)development: morphogenetic regulators, Hox genes and cell type markers for the ectodermal and neural lineages. These biomarker groups were selected based on their crucial regulatory role in (neuro)development. Analysis of these genes in a series of previously generated whole transcriptome datasets of ESTn showed that at day 7 in culture cell differentiation resembled hindbrain/branchial/thoracic development between E6.5-E12.5 in vivo, with subsequent development into a mixed cell culture containing different neural subtypes, astrocytes and oligodendrocytes by day 13. In addition, the selected biomarkers showed common and distinct responses to compound exposure. Monitoring the biological domain of ESTn through gene expression patterns of morphogenetic regulators, Hox genes and cell type markers proved instrumental in providing mechanistic understanding of compound effects on neural differentiation in ESTn, and can aid in positioning of the test in a battery of complementary in vitro tests in integrated approaches to testing and assessment.
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Affiliation(s)
- Victoria C de Leeuw
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands.
| | - Jeroen L A Pennings
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Ellen V S Hessel
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Aldert H Piersma
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
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7
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Raposo RDS, Pinto DV, Moreira R, Dias RP, Fontes Ribeiro CA, Oriá RB, Malva JO. Methylmercury Impact on Adult Neurogenesis: Is the Worst Yet to Come From Recent Brazilian Environmental Disasters? Front Aging Neurosci 2020; 12:591601. [PMID: 33328968 PMCID: PMC7719787 DOI: 10.3389/fnagi.2020.591601] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022] Open
Abstract
Worldwide environmental tragedies of anthropogenic origin causing massive release of metals and other pollutants have been increasing considerably. These pollution outbreaks affect the ecosystems and impact human health. Among those tragedies, recent large-scale environmental disasters in Brazil strongly affected riverside populations, leading to high-risk exposure to methylmercury (MeHg). MeHg is highly neurotoxic to the developing brain. This toxicant causes neural stem cell dysfunction and neurodevelopmental abnormalities. However, less is known about the effects of MeHg in the postnatal neurogenic niche, which harbors neural stem cells and their progeny, in the adult brain. Therefore, taking in consideration the impact of MeHg in human health it is urgent to clarify possible associations between exposure to mercury, accelerated cognitive decline, and neurodegenerative diseases. In this perspectives paper, we discuss the neurotoxic mechanisms of MeHg on postnatal neurogenesis and the putative implications associated with accelerated brain aging and early-onset cognitive decline in populations highly exposed to this environmental neurotoxicant.
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Affiliation(s)
- Ramon da Silva Raposo
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB) and Institute of Pharmacology and Experimental Therapeutics, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, Coimbra, Portugal
- Experimental Biology Core, Health Sciences Center, University of Fortaleza, Fortaleza, Brazil
| | - Daniel Vieira Pinto
- Laboratory of Tissue Healing, Ontogeny and Nutrition, Department of Morphology, School of Medicine, Institute of Biomedicine, Federal University of Ceara, Fortaleza, Brazil
| | - Ricardo Moreira
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB) and Institute of Pharmacology and Experimental Therapeutics, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, Coimbra, Portugal
| | - Ronaldo Pereira Dias
- Laboratory of Tissue Healing, Ontogeny and Nutrition, Department of Morphology, School of Medicine, Institute of Biomedicine, Federal University of Ceara, Fortaleza, Brazil
| | - Carlos Alberto Fontes Ribeiro
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB) and Institute of Pharmacology and Experimental Therapeutics, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, Coimbra, Portugal
| | - Reinaldo Barreto Oriá
- Laboratory of Tissue Healing, Ontogeny and Nutrition, Department of Morphology, School of Medicine, Institute of Biomedicine, Federal University of Ceara, Fortaleza, Brazil
| | - João Oliveira Malva
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB) and Institute of Pharmacology and Experimental Therapeutics, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, Coimbra, Portugal
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8
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de Leeuw VC, van Nieuwland M, Bokkers BGH, Piersma AH. Culture Conditions Affect Chemical-Induced Developmental Toxicity In Vitro: The Case of Folic Acid, Methionine and Methotrexate in the Neural Embryonic Stem Cell Test. Altern Lab Anim 2020; 48:173-183. [PMID: 33034509 DOI: 10.1177/0261192920961963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In vitro tests are increasingly applied in chemical hazard assessment. Basic culture conditions may affect the outcome of in vitro tests and should be optimised to reduce false predictions. The neural embryonic stem cell test (ESTn) can predict early neurodevelopmental effects of chemicals, as it mimics the differentiation of stem cells towards the neuroectodermal lineage. Normal early neural differentiation depends crucially on folic acid (FA) and methionine (MET), both elements of the one-carbon (1C) cycle. The aim of this study was to assess the concentration-dependent influence of FA and MET on neural differentiation in the ESTn, and its consequences for assay sensitivity to methotrexate (MTX), a compound that interferes with the 1C cycle. Neural differentiation was inhibited below 0.007 mM and above 0.22 mM FA, while both stem cell viability (< 0.097 mM, > 1.52 mM) and neural differentiation (< 0.181 mM, > 1.35 mM) were affected when changing MET concentrations. A 10-day exposure to 13 nM MTX inhibited neural differentiation, especially in FA- and MET-deficient conditions. However, a 24-hour exposure to 39 nM MTX decreased neural cell and neural crest cell differentiation markers only when the concentration of FA in the medium was three times the standard concentration, which was expected to have a protective effect against MTX. These results show the importance of nutrient concentrations, exposure scenarios and timing of read-outs for cell differentiation and compound sensitivity in the ESTn. Caution should be taken when interpreting results from a single in vitro test, especially when extrapolating to effects on complex morphogenetic processes, like neural tube development.
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Affiliation(s)
- Victoria C de Leeuw
- Centre for Health Protection, National Institute for Public Health and the Environment (10206RIVM), Bilthoven, the Netherlands.,Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
| | - Marieke van Nieuwland
- Centre for Health Protection, National Institute for Public Health and the Environment (10206RIVM), Bilthoven, the Netherlands.,Radboudumc, Medical Faculty, Nijmegen, the Netherlands
| | - Bas G H Bokkers
- Centre for Health Protection, National Institute for Public Health and the Environment (10206RIVM), Bilthoven, the Netherlands.,Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (10206RIVM), Bilthoven, the Netherlands
| | - Aldert H Piersma
- Centre for Health Protection, National Institute for Public Health and the Environment (10206RIVM), Bilthoven, the Netherlands.,Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
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9
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Mennen RH, de Leeuw VC, Piersma AH. Oxygen tension influences embryonic stem cell maintenance and has lineage specific effects on neural and cardiac differentiation. Differentiation 2020; 115:1-10. [PMID: 32738735 DOI: 10.1016/j.diff.2020.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/08/2020] [Indexed: 02/06/2023]
Abstract
The importance of oxygen tension in in vitro cultures and its effect on embryonic stem cell (ESC) differentiation has been widely acknowledged. Research has mainly focussed on ESC maintenance or on one line of differentiation and only few studies have examined the potential relation between oxygen tension during ESC maintenance and differentiation. In this study we investigated the influence of atmospheric (20%) versus physiologic (5%) oxygen tension in ESC cultures and their differentiation within the cardiac and neural embryonic stem cell tests (ESTc, ESTn). Oxygen tension was set at 5% or 20% and cells were kept in these conditions from starting up cell culture until use for differentiation. Under these oxygen tensions, ESC culture showed no differences in proliferation and gene and protein expression levels. Differentiation was either performed in the same or in the alternative oxygen tension compared to ESC culture creating four different experimental conditions. Cardiac differentiation in 5% instead of 20% oxygen resulted in reduced development of spontaneously beating cardiomyocytes and lower expression of cardiac markers Nkx2.5, Myh6 and MF20 (myosin), regardless whether ESC had been cultured in 5% or 20% oxygen tension. As compared to the control (20% oxygen during stem cell maintenance and differentiation), neural differentiation in 5% oxygen with ESC cultured in 20% oxygen led to more cardiac and neural crest cell differentiation. The opposite experimental condition of neural differentiation in 20% oxygen with ESC cultured in 5% oxygen resulted in more glial differentiation. ESC that were maintained and differentiated in 5% oxygen showed an increase in neural crest and oligodendrocytes as compared to 20% oxygen during stem cell maintenance and differentiation. This study showed major effects on ESC differentiation in ESTc and ESTn of oxygen tension, which is an important variable to consider when designing and developing a stem cell-based in vitro system.
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Affiliation(s)
- Regina H Mennen
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands.
| | - Victoria C de Leeuw
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
| | - Aldert H Piersma
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
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10
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Defining embryonic developmental effects of chemical mixtures using the embryonic stem cell test. Food Chem Toxicol 2020; 140:111284. [DOI: 10.1016/j.fct.2020.111284] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/19/2020] [Accepted: 03/16/2020] [Indexed: 12/23/2022]
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11
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Wegner SH, Park JJ, Workman T, Hermsen SAB, Wallace J, Stanaway IB, Kim HY, Griffith WC, Hong S, Faustman EM. Anchoring a dynamic in vitro model of human neuronal differentiation to key processes of early brain development in vivo. Reprod Toxicol 2020; 91:116-130. [PMID: 31740287 PMCID: PMC6980388 DOI: 10.1016/j.reprotox.2019.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 01/04/2023]
Abstract
We characterize temporal pathway dynamics of differentiation in an in vitro neurotoxicity model with the aim of informing design and interpretation of toxicological assays. Human neural progenitor cells (hNPCs) were cultured in differentiation conditions up to 21 days. Genes significantly changed through time were identified and grouped according to temporal dynamics. Quantitative pathway analysis identified gene ontology (GO) terms enriched among significantly changed genes and provided a temporal roadmap of pathway trends in vitro. Gene expression in hNPCs was compared with publicly available gene expression data from developing human brain tissue in vivo. Quantitative pathway analysis of significantly changed genes and targeted analysis of specific pathways of interest identified concordance between in vivo and in vitro expression associated with proliferation, migration, differentiation, synapse formation, and neurotransmission. Our analysis anchors gene expression patterns in vitro to sensitive windows of in vivo development, helping to define appropriate applications of the model.
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Affiliation(s)
- Susanna H Wegner
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Julie Juyoung Park
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Tomomi Workman
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Sanne A B Hermsen
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Jim Wallace
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Ian B Stanaway
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Hee Yeon Kim
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - William C Griffith
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Sungwoo Hong
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States
| | - Elaine M Faustman
- Institute for Risk Analysis and Risk Communication, Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, United States.
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12
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Differential effects of fluoxetine and venlafaxine in the neural embryonic stem cell test (ESTn) revealed by a cell lineage map. Neurotoxicology 2019; 76:1-9. [PMID: 31593710 DOI: 10.1016/j.neuro.2019.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/21/2019] [Accepted: 09/22/2019] [Indexed: 01/21/2023]
Abstract
There is a need for in vitro tests for the evaluation of chemicals and pharmaceuticals that may cause developmental neurotoxicity (DNT) in humans. The neural embryonic stem cell test (ESTn) is such an in vitro test that mimics early neural differentiation. The aim of this study was to define the biological domain of ESTn based on the expression of selective markers for certain cell types, and to investigate the effects of two antidepressants, fluoxetine (FLX) and venlafaxine (VNX), on neural differentiation. A cell lineage map was made to track neural differentiation and the effects of FLX and VNX in ESTn. Whole transcriptome analysis revealed differentiation from an embryonic stem cell population to a mixed culture of neural progenitors, neurons and neural crest cells 7 days into differentiation. Maturing neurons, astrocytes and oligodendrocytes were present after 13 days. Exposure to FLX or VNX led to different expression patterns between compounds at both time points. On day 7, both compounds upregulated most of the stem cell- and immature neuron markers, but had distinct effects on neural subtype markers. FLX downregulated glycinergic markers and upregulated cholinergic markers, while VNX had the opposite effect. On day 13, FLX and VNX affected their specific therapeutic targets, represented by mainly serotonergic markers by FLX- and dopaminergic and noradrenergic markers in VNX-exposed cultures, as well as oligodendrocyte and glycinergic neuron markers. This proof of concept study shows the added value of assessing DNT in ESTn through a cell lineage map and gives mechanistic insight in the potential neurodevelopmental effects of FLX and VNX. More compounds should be tested to further evaluate the use of the cell lineage map.
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13
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Raciti M, Salma J, Spulber S, Gaudenzi G, Khalajzeyqami Z, Conti M, Anderlid BM, Falk A, Hermanson O, Ceccatelli S. NRXN1 Deletion and Exposure to Methylmercury Increase Astrocyte Differentiation by Different Notch-Dependent Transcriptional Mechanisms. Front Genet 2019; 10:593. [PMID: 31316548 PMCID: PMC6610538 DOI: 10.3389/fgene.2019.00593] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 06/05/2019] [Indexed: 01/11/2023] Open
Abstract
Controversial evidence points to a possible involvement of methylmercury (MeHg) in the etiopathogenesis of autism spectrum disorders (ASD). In the present study, we used human neuroepithelial stem cells from healthy donors and from an autistic patient bearing a bi-allelic deletion in the gene encoding for NRXN1 to evaluate whether MeHg would induce cellular changes comparable to those seen in cells derived from the ASD patient. In healthy cells, a subcytotoxic concentration of MeHg enhanced astroglial differentiation similarly to what observed in the diseased cells (N1), as shown by the number of GFAP positive cells and immunofluorescence signal intensity. In both healthy MeHg-treated and N1 untreated cells, aberrations in Notch pathway activity seemed to play a critical role in promoting the differentiation toward glia. Accordingly, treatment with the established Notch inhibitor DAPT reversed the altered differentiation. Although our data are not conclusive since only one of the genes involved in ASD is considered, the results provide novel evidence suggesting that developmental exposure to MeHg, even at subcytotoxic concentrations, induces alterations in astroglial differentiation similar to those observed in ASD.
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Affiliation(s)
- Marilena Raciti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Jahan Salma
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Stefan Spulber
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Giulia Gaudenzi
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | - Mirko Conti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Britt-Marie Anderlid
- Centre for Molecular Medicine, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ola Hermanson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Sandra Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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14
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Prince LM, Aschner M, Bowman AB. Human-induced pluripotent stems cells as a model to dissect the selective neurotoxicity of methylmercury. Biochim Biophys Acta Gen Subj 2019; 1863:129300. [PMID: 30742955 DOI: 10.1016/j.bbagen.2019.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 01/09/2019] [Accepted: 02/01/2019] [Indexed: 01/07/2023]
Abstract
Methylmercury (MeHg) is a potent neurotoxicant affecting both the developing and mature central nervous system (CNS) with apparent indiscriminate disruption of multiple homeostatic pathways. However, genetic and environmental modifiers contribute significant variability to neurotoxicity associated with human exposures. MeHg displays developmental stage and neural lineage selective neurotoxicity. To identify mechanistic-based neuroprotective strategies to mitigate human MeHg exposure risk, it will be critical to improve our understanding of the basis of MeHg neurotoxicity and of this selective neurotoxicity. Here, we propose that human-based pluripotent stem cell cellular approaches may enable mechanistic insight into genetic pathways that modify sensitivity of specific neural lineages to MeHg-induced neurotoxicity. Such studies are crucial for the development of novel disease modifying strategies impinging on MeHg exposure vulnerability.
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Affiliation(s)
- Lisa M Prince
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, United States.
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15
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de Leeuw VC, Hessel EVS, Piersma AH. Look-alikes may not act alike: Gene expression regulation and cell-type-specific responses of three valproic acid analogues in the neural embryonic stem cell test (ESTn). Toxicol Lett 2018; 303:28-37. [PMID: 30578912 DOI: 10.1016/j.toxlet.2018.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/07/2018] [Accepted: 12/13/2018] [Indexed: 12/20/2022]
Abstract
In vitro assays to assess developmental neurotoxicity of chemicals are highly desirable. The murine neural embryonic stem cell test (ESTn) can mimic parts of early differentiation of embryonic brain and may therefore be useful for this purpose. The aim of this study was to investigate whether this test is able to rank the toxic potencies of three valproic acid analogues and to study their mode of action by investigating their individual effects on four cell types: stem cells, neurons, astrocytes and neural crest cells. Using immunocytochemical read-outs and qPCR for cell type-specific genes, the effects of valproic acid (VPA), 2-ethylhexanoic acid (EHA) and 2-ethyl-4-methylpentanoic (EMPA) were assessed. VPA and EHA but not EMPA downregulated cell type-specific differentiation makers and upregulated stem cell related markers (Fut4, Cdh1) at different time points during differentiation. Expression of Gfap, a marker for astrocytes, was dramatically downregulated by VPA and EHA, but not by EMPA. This finding was verified using immunostainings. Based on the number and extent of genes regulated by the three compounds, relative potencies were determined as VPA > EHA > EMPA, which is consistent with in vivo developmental toxicity potency ranking of these compounds. Thus, ESTn using a combination of morphology, gene and protein expression readouts, may provide a medium-throughput system for monitoring the effects of compounds on differentiation of cell types in early brain development.
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Affiliation(s)
- Victoria C de Leeuw
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands.
| | - Ellen V S Hessel
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Aldert H Piersma
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
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16
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Miranda CC, Fernandes TG, Pinto SN, Prieto M, Diogo MM, Cabral JM. A scale out approach towards neural induction of human induced pluripotent stem cells for neurodevelopmental toxicity studies. Toxicol Lett 2018; 294:51-60. [DOI: 10.1016/j.toxlet.2018.05.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/28/2018] [Accepted: 05/04/2018] [Indexed: 12/30/2022]
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17
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Luz AL, Tokar EJ. Pluripotent Stem Cells in Developmental Toxicity Testing: A Review of Methodological Advances. Toxicol Sci 2018; 165:31-39. [PMID: 30169765 PMCID: PMC6111785 DOI: 10.1093/toxsci/kfy174] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Millions of children are born each year with a birth defect. Many of these defects are caused by environmental factors, although the underlying etiology is often unknown. In vivo mammalian models are frequently used to determine if a chemical poses a risk to the developing fetus. However, there are over 80 000 chemicals registered for use in the United States, many of which have undergone little safety testing, necessitating the need for higher-throughput methods to assess developmental toxicity. Pluripotent stem cells (PSCs) are an ideal in vitro model to investigate developmental toxicity as they possess the capacity to differentiate into nearly any cell type in the human body. Indeed, a burst of research has occurred in the field of stem cell toxicology over the past decade, which has resulted in numerous methodological advances that utilize both mouse and human PSCs, as well as cutting-edge technology in the fields of metabolomics, transcriptomics, transgenics, and high-throughput imaging. Here, we review the wide array of approaches used to detect developmental toxicants, suggest areas for further research, and highlight critical aspects of stem cell biology that should be considered when utilizing PSCs in developmental toxicity testing.
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Affiliation(s)
- Anthony L Luz
- Stem Cell Toxicology Group, National Toxicology Program Laboratory, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Erik J Tokar
- Stem Cell Toxicology Group, National Toxicology Program Laboratory, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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18
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Flow Cytometry to Evaluate Potential Developmental Toxicants in the Embryonic Stem Cell. Methods Mol Biol 2018. [PMID: 29896691 DOI: 10.1007/978-1-4939-7883-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Embryonic stem cells (ESC) are widely used due to their unlimited capacity of differentiation into different cell lineages, which makes ESC a viable choice as a toxicology test model. Toxicological analysis using embryonic stem cells (ESC) has become an important tool in toxicology procedures. Regarding toxicological analysis methods, flow cytometry (FC) is one technique designed to detect and evaluate cells in suspension, for example, ESC suspension, thus making possible to study different biological, physical, and/or chemical characteristics of cells. Thus, FC can be very useful for cell toxicology and tumorigenic analyses.
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19
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Hessel EVS, Staal YCM, Piersma AH. Design and validation of an ontology-driven animal-free testing strategy for developmental neurotoxicity testing. Toxicol Appl Pharmacol 2018; 354:136-152. [PMID: 29544899 DOI: 10.1016/j.taap.2018.03.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/26/2018] [Accepted: 03/11/2018] [Indexed: 12/26/2022]
Abstract
Developmental neurotoxicity entails one of the most complex areas in toxicology. Animal studies provide only limited information as to human relevance. A multitude of alternative models have been developed over the years, providing insights into mechanisms of action. We give an overview of fundamental processes in neural tube formation, brain development and neural specification, aiming at illustrating complexity rather than comprehensiveness. We also give a flavor of the wealth of alternative methods in this area. Given the impressive progress in mechanistic knowledge of human biology and toxicology, the time is right for a conceptual approach for designing testing strategies that cover the integral mechanistic landscape of developmental neurotoxicity. The ontology approach provides a framework for defining this landscape, upon which an integral in silico model for predicting toxicity can be built. It subsequently directs the selection of in vitro assays for rate-limiting events in the biological network, to feed parameter tuning in the model, leading to prediction of the toxicological outcome. Validation of such models requires primary attention to coverage of the biological domain, rather than classical predictive value of individual tests. Proofs of concept for such an approach are already available. The challenge is in mining modern biology, toxicology and chemical information to feed intelligent designs, which will define testing strategies for neurodevelopmental toxicity testing.
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Affiliation(s)
- Ellen V S Hessel
- Center for Health Protection, National Institute for Public Health and The Environment (RIVM), P.O. Box 1, 3720BA Bilthoven, The Netherlands.
| | - Yvonne C M Staal
- Center for Health Protection, National Institute for Public Health and The Environment (RIVM), P.O. Box 1, 3720BA Bilthoven, The Netherlands
| | - Aldert H Piersma
- Center for Health Protection, National Institute for Public Health and The Environment (RIVM), P.O. Box 1, 3720BA Bilthoven, The Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
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20
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Yao X, Yin N, Faiola F. Stem cell toxicology: a powerful tool to assess pollution effects on human health. Natl Sci Rev 2016. [DOI: 10.1093/nsr/nww089] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AbstractEnvironmental pollution is a global problem; the lack of comprehensive toxicological assessments may lead to increased health risks. To fully understand the health effects of pollution, it is paramount to implement fast, efficient and specific toxicity screening that relies on human models rather than on time-consuming, expensive and often inaccurate tests involving live animals. Human stem cell toxicology represents a valid alternative to traditional toxicity assays because it takes advantage of the ability of stem cells to differentiate into multiple cell types and tissues of the human body. Thus, this branch of toxicology provides a possibility to assess cellular, embryonic, developmental, reproductive and functional toxicity in vitro within a single system highly relevant to human physiology. In this review, we describe the development, performance and future perspectives of stem cell toxicology, with an emphasis on how it can meet the increasing challenges posed by environmental pollution in the modern world.
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Affiliation(s)
- Xinglei Yao
- Stake Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nuoya Yin
- Stake Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Francesco Faiola
- Stake Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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21
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Kim HY, Wegner SH, Van Ness KP, Park JJ, Pacheco SE, Workman T, Hong S, Griffith W, Faustman EM. Differential epigenetic effects of chlorpyrifos and arsenic in proliferating and differentiating human neural progenitor cells. Reprod Toxicol 2016; 65:212-223. [PMID: 27523287 DOI: 10.1016/j.reprotox.2016.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 07/21/2016] [Accepted: 08/10/2016] [Indexed: 12/16/2022]
Abstract
Understanding the underlying temporal and mechanistic responses to neurotoxicant exposures during sensitive periods of neuronal development are critical for assessing the impact of these exposures on developmental processes. To investigate the importance of timing of neurotoxicant exposure for perturbation of epigenetic regulation, we exposed human neuronal progenitor cells (hNPCs) to chlorpyrifos (CP) and sodium arsenite (As; positive control) during proliferation and differentiation. CP or As treatment effects on hNPCs morphology, cell viability, and changes in protein expression levels of neural differentiation and cell stress markers, and histone H3 modifications were examined. Cell viability, proliferation/differentiation status, and epigenetic results suggest that hNPCs cultures respond to CP and As treatment with different degrees of sensitivity. Histone modifications, as measured by changes in histone H3 phosphorylation, acetylation and methylation, varied for each toxicant and growth condition, suggesting that differentiation status can influence the epigenetic effects of CP and As exposures.
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Affiliation(s)
- Hee Yeon Kim
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Susanna H Wegner
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Kirk P Van Ness
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Julie Juyoung Park
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Sara E Pacheco
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Tomomi Workman
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Sungwoo Hong
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - William Griffith
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Elaine M Faustman
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States.
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22
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Schmidt BZ, Lehmann M, Gutbier S, Nembo E, Noel S, Smirnova L, Forsby A, Hescheler J, Avci HX, Hartung T, Leist M, Kobolák J, Dinnyés A. In vitro acute and developmental neurotoxicity screening: an overview of cellular platforms and high-throughput technical possibilities. Arch Toxicol 2016; 91:1-33. [PMID: 27492622 DOI: 10.1007/s00204-016-1805-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 07/07/2016] [Indexed: 01/03/2023]
Abstract
Neurotoxicity and developmental neurotoxicity are important issues of chemical hazard assessment. Since the interpretation of animal data and their extrapolation to man is challenging, and the amount of substances with information gaps exceeds present animal testing capacities, there is a big demand for in vitro tests to provide initial information and to prioritize for further evaluation. During the last decade, many in vitro tests emerged. These are based on animal cells, human tumour cell lines, primary cells, immortalized cell lines, embryonic stem cells, or induced pluripotent stem cells. They differ in their read-outs and range from simple viability assays to complex functional endpoints such as neural crest cell migration. Monitoring of toxicological effects on differentiation often requires multiomics approaches, while the acute disturbance of neuronal functions may be analysed by assessing electrophysiological features. Extrapolation from in vitro data to humans requires a deep understanding of the test system biology, of the endpoints used, and of the applicability domains of the tests. Moreover, it is important that these be combined in the right way to assess toxicity. Therefore, knowledge on the advantages and disadvantages of all cellular platforms, endpoints, and analytical methods is essential when establishing in vitro test systems for different aspects of neurotoxicity. The elements of a test, and their evaluation, are discussed here in the context of comprehensive prediction of potential hazardous effects of a compound. We summarize the main cellular characteristics underlying neurotoxicity, present an overview of cellular platforms and read-out combinations assessing distinct parts of acute and developmental neurotoxicology, and highlight especially the use of stem cell-based test systems to close gaps in the available battery of tests.
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Affiliation(s)
- Béla Z Schmidt
- BioTalentum Ltd., Gödöllő, Hungary.,Stem Cell Biology and Embryology Unit, Department of Development and Regeneration, Stem Cell Institute Leuven, KU Leuven, Leuven, Belgium
| | - Martin Lehmann
- BioTalentum Ltd., Gödöllő, Hungary.,Institute of Neurophysiology and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Simon Gutbier
- Doerenkamp-Zbinden Chair for In Vitro Toxicology and Biomedicine, University of Konstanz, Constance, Germany
| | - Erastus Nembo
- BioTalentum Ltd., Gödöllő, Hungary.,Institute of Neurophysiology and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Sabrina Noel
- Louvain Centre for Toxicology and Applied Pharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Lena Smirnova
- Center for Alternatives to Animal Testing, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Anna Forsby
- Swedish Toxicology Research Center (Swetox), Södertälje, Sweden.,Department of Neurochemistry, Stockholm University, Stockholm, Sweden
| | - Jürgen Hescheler
- Institute of Neurophysiology and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Hasan X Avci
- BioTalentum Ltd., Gödöllő, Hungary.,Department of Medical Chemistry, University of Szeged, Szeged, Hungary
| | - Thomas Hartung
- Center for Alternatives to Animal Testing, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Marcel Leist
- Doerenkamp-Zbinden Chair for In Vitro Toxicology and Biomedicine, University of Konstanz, Constance, Germany
| | | | - András Dinnyés
- BioTalentum Ltd., Gödöllő, Hungary. .,Molecular Animal Biotechnology Laboratory, Szent István University, Gödöllő, 2100, Hungary.
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23
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Schulpen SH, Theunissen PT, Pennings JL, Piersma AH. Comparison of gene expression regulation in mouse- and human embryonic stem cell assays during neural differentiation and in response to valproic acid exposure. Reprod Toxicol 2015; 56:77-86. [DOI: 10.1016/j.reprotox.2015.06.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/01/2015] [Accepted: 06/02/2015] [Indexed: 12/15/2022]
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24
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Schulpen SHW, Pennings JLA, Piersma AH. Gene Expression Regulation and Pathway Analysis After Valproic Acid and Carbamazepine Exposure in a Human Embryonic Stem Cell-Based Neurodevelopmental Toxicity Assay. Toxicol Sci 2015; 146:311-20. [PMID: 25979313 DOI: 10.1093/toxsci/kfv094] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Differentiating pluripotent stem cells in vitro have proven useful for the study of developmental toxicity. Here, we studied the effects of anticonvulsant drug exposure in a human embryonic stem cell (hESC)-based neurodevelopmental toxicity test (hESTn). During neural differentiation the cells were exposed, for either 1 or 7 days, to noncytotoxic concentration ranges of valproic acid (VPA) or carbamazepine (CBZ), antiepileptic drugs known to cause neurodevelopmental toxicity. The effects observed on gene expression and correlated processes and pathways were in line with processes associated with neural development and pharmaceutical mode of action. In general, VPA showed a higher number of genes and molecular pathways affected than CBZ. The response kinetics differed between both compounds, with CBZ showing higher response magnitudes at day 1, versus VPA at day 7. With this study, we demonstrated the potential and biological relevance of the application of this hESC-based differentiation assay in combination with transcriptomics, as a tool to study neurodevelopmental toxicity.
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Affiliation(s)
- Sjors H W Schulpen
- *Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands and Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jeroen L A Pennings
- *Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands and
| | - Aldert H Piersma
- *Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands and Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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25
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Fritsche E, Alm H, Baumann J, Geerts L, Håkansson H, Masjosthusmann S, Witters H. Literature review on in vitro and alternative Developmental Neurotoxicity (DNT) testing methods. ACTA ACUST UNITED AC 2015. [DOI: 10.2903/sp.efsa.2015.en-778] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ellen Fritsche
- Leibniz Research Institute for Environmental Medicine (IUF), Group of Sphere Models and Risk Assessment, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Henrik Alm
- Leibniz Research Institute for Environmental Medicine (IUF), Group of Sphere Models and Risk Assessment, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Jenny Baumann
- Leibniz Research Institute for Environmental Medicine (IUF), Group of Sphere Models and Risk Assessment, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Lieve Geerts
- Flemish Institute for Technological Research (VITO), Environmental Risk & Health, Boeretang 200, B‐2400 Mol, Belgium
| | - Helen Håkansson
- Karolinska Institute (KI), Institute of Environmental Medicine (IMM), Unit of Environmental Health Risk Assessment, SE‐171 77 Stockholm, Sweden
| | - Stefan Masjosthusmann
- Leibniz Research Institute for Environmental Medicine (IUF), Group of Sphere Models and Risk Assessment, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Hilda Witters
- Flemish Institute for Technological Research (VITO), Environmental Risk & Health, Boeretang 200, B‐2400 Mol, Belgium
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26
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Schulpen SHW, de Jong E, de la Fonteyne LJJ, de Klerk A, Piersma AH. Distinct gene expression responses of two anticonvulsant drugs in a novel human embryonic stem cell based neural differentiation assay protocol. Toxicol In Vitro 2014; 29:449-57. [PMID: 25524013 DOI: 10.1016/j.tiv.2014.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/14/2014] [Accepted: 12/03/2014] [Indexed: 12/23/2022]
Abstract
Hazard assessment of chemicals and pharmaceuticals is increasingly gaining from knowledge about molecular mechanisms of toxic action acquired in dedicated in vitro assays. We have developed an efficient human embryonic stem cell neural differentiation test (hESTn) that allows the study of the molecular interaction of compounds with the neural differentiation process. Within the 11-day differentiation protocol of the assay, embryonic stem cells lost their pluripotency, evidenced by the reduced expression of stem cell markers Pou5F1 and Nanog. Moreover, stem cells differentiated into neural cells, with morphologically visible neural structures together with increased expression of neural differentiation-related genes such as βIII-tubulin, Map2, Neurogin1, Mapt and Reelin. Valproic acid (VPA) and carbamazepine (CBZ) exposure during hESTn differentiation led to concentration-dependent reduced expression of βIII-tubulin, Neurogin1 and Reelin. In parallel VPA caused an increased gene expression of Map2 and Mapt which is possibly related to the neural protective effect of VPA. These findings illustrate the added value of gene expression analysis for detecting compound specific effects in hESTn. Our findings were in line with and could explain effects observed in animal studies. This study demonstrates the potential of this assay protocol for mechanistic analysis of specific compound-induced inhibition of human neural cell differentiation.
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Affiliation(s)
- Sjors H W Schulpen
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
| | - Esther de Jong
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | - Liset J J de la Fonteyne
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands
| | - Arja de Klerk
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands
| | - Aldert H Piersma
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
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27
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van Dartel DA, Schulpen SH, Theunissen PT, Bunschoten A, Piersma AH, Keijer J. Dynamic changes in energy metabolism upon embryonic stem cell differentiation support developmental toxicant identification. Toxicology 2014; 324:76-87. [DOI: 10.1016/j.tox.2014.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 07/24/2014] [Accepted: 07/24/2014] [Indexed: 02/06/2023]
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An integrated approach for detecting embryotoxicity and developmental toxicity of environmental contaminants using in vitro alternative methods. Toxicol Lett 2014; 230:356-67. [DOI: 10.1016/j.toxlet.2014.01.037] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/10/2013] [Accepted: 01/27/2014] [Indexed: 11/19/2022]
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Using Pluripotent Stem Cells and Their Progeny as an In VitroModel to Assess (Developmental) Neurotoxicity. METHODS AND PRINCIPLES IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1002/9783527674183.ch13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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30
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de Jong E, van Beek L, Piersma AH. Comparison of osteoblast and cardiomyocyte differentiation in the embryonic stem cell test for predicting embryotoxicity in vivo. Reprod Toxicol 2014; 48:62-71. [DOI: 10.1016/j.reprotox.2014.03.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 03/19/2014] [Indexed: 01/11/2023]
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Estevan C, Fuster E, Del Río E, Pamies D, Vilanova E, Sogorb MA. Organophosphorus pesticide chlorpyrifos and its metabolites alter the expression of biomarker genes of differentiation in D3 mouse embryonic stem cells in a comparable way to other model neurodevelopmental toxicants. Chem Res Toxicol 2014; 27:1487-95. [PMID: 25137620 DOI: 10.1021/tx500051k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There are discrepancies about whether chlorpyrifos is able to induce neurodevelopmental toxicity or not. We previously reported alterations in the pattern of expression of biomarker genes of differentiation in D3 mouse embryonic stem cells caused by chlorpyrifos and its metabolites chlorpyrifos-oxon and 3,5,6-trichloro-2-pyridinol. Now, we reanalyze these data comparing the effects on these genes with those caused in the same genes by retinoic acid, valproic acid, and penicillin-G (model compounds considered as strong, weak, and non-neurodevelopmental toxicants, respectively). We also compare the effects of chlorpyrifos and its metabolites on the cell viability of D3 cells and 3T3 mouse fibroblasts with the effects caused in the same cells by the three model compounds. We conclude that chlorpyrifos and its metabolites act, regarding these end-points, as the weak neurodevelopmental toxicant valproic acid, and consequently, a principle of caution should be applied avoiding occupational exposures in pregnant women. A second independent experiment run with different cellular batches coming from the same clone obtained the same result as the first one.
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Affiliation(s)
- Carmen Estevan
- Unidad de Toxicología y Seguridad Química, Instituto de Bioingeniería, Universidad Miguel Hernández de Elche , Avenida de la Universidad s/n, 03202-Elche, Spain
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Jebbett NJ, Hamilton JW, Rand MD, Eckenstein F. Low level methylmercury enhances CNTF-evoked STAT3 signaling and glial differentiation in cultured cortical progenitor cells. Neurotoxicology 2013; 38:91-100. [PMID: 23845766 DOI: 10.1016/j.neuro.2013.06.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 06/26/2013] [Accepted: 06/28/2013] [Indexed: 01/18/2023]
Abstract
Although many previous investigations have studied how mercury compounds cause cell death, sub-cytotoxic levels may affect mechanisms essential for the proper development of the nervous system. The present study investigates whether low doses of methylmercury (MeHg) and mercury chloride (HgCl2) can modulate the activity of JAK/STAT signaling, a pathway that promotes gliogenesis. We report that sub-cytotoxic doses of MeHg enhance ciliary neurotrophic factor (CNTF) evoked STAT3 phosphorylation in human SH-SY5Y neuroblastoma and mouse cortical neural progenitor cells (NPCs). This effect is specific for MeHg, since HgCl2 fails to enhance JAK/STAT signaling. Exposing NPCs to these low doses of MeHg (30-300nM) enhances CNTF-induced expression of STAT3-target genes such as glial fibrillary acidic protein (GFAP) and suppressors of cytokine signaling 3 (SOCS3), and increases the proportion of cells expressing GFAP following 2 days of differentiation. Higher, near-cytotoxic concentrations of MeHg and HgCl2 inhibit STAT3 phosphorylation and lead to increased production of superoxide. Lower concentrations of MeHg effective in enhancing JAK/STAT signaling (30nM) do not result in a detectable increase in superoxide nor increased expression of the oxidant-responsive genes, heme oxygenase 1, heat shock protein A5 and sirtuin 1. These findings suggest that low concentrations of MeHg inappropriately enhance STAT3 phosphorylation and glial differentiation, and that the mechanism causing this enhancement is distinct from the reactive oxygen species-associated cell death observed at higher concentrations of MeHg and HgCl2.
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Affiliation(s)
- Nathan J Jebbett
- University of Vermont, Department of Neurological Sciences, Burlington, VT, United States
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Ceccatelli S, Bose R, Edoff K, Onishchenko N, Spulber S. Long-lasting neurotoxic effects of exposure to methylmercury during development. J Intern Med 2013; 273:490-7. [PMID: 23600401 DOI: 10.1111/joim.12045] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amongst environmental chemical contaminants, methylmercury (MeHg) remains a major concern because of its detrimental effects on developing organisms, which appear to be particularly susceptible to its toxicity. Here, we investigated the effects of low MeHg levels on the development of the nervous system using both in vitro and in vivo experimental models. In neural stem cells (NSCs), MeHg decreased proliferation and neuronal differentiation and induced cellular senescence associated with impairment in mitochondrial function and a concomitant decrease in global DNA methylation. Interestingly, the effects were heritable and could be observed in daughter NSCs never directly exposed to MeHg. By chronically exposing pregnant/lactating mice to MeHg, we found persistent behavioural changes in the male offspring, which exhibited depression-like behaviour that could be reversed by chronic treatment with the antidepressant fluoxetine. The behavioural alterations were associated with a decreased number of proliferating cells and lower expression of brain-derived neurotrophic factor (Bdnf) mRNA in the hippocampal dentate gyrus. MeHg exposure also induced long-lasting DNA hypermethylation, increased histone H3-K27 tri-methylation and decreased H3 acetylation at the Bdnf promoter IV, indicating that epigenetic mechanisms play a critical role in mediating the long-lasting effects of perinatal exposure to MeHg. Fluoxetine treatment restored the Bdnf mRNA expression levels, as well as the number of proliferating cells in the granule cell layer of the dentate gyrus, which further supports the hypothesis that links depression to impaired neurogenesis. Altogether, our findings have shown that low concentrations of MeHg induce long-lasting effects in NSCs that can potentially predispose individuals to depression, which we have reported earlier to occur in experimental animals exposed to MeHg during prenatal and early postnatal development.
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Affiliation(s)
- S Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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Abstract
Toxicological hazard assessment currently finds itself at a crossroads where the existing classical test paradigm is challenged by a host of innovative approaches. Animal study protocols are being enhanced for additional parameters and improved for more efficient effect assessment with reduced animal numbers. Whilst existing testing paradigms have generally proven conservative for chemical safety assessment, novel alternative in silico and in vitro approaches and assays are being introduced that begin to elucidate molecular mechanisms of toxicity. Issues such as animal welfare, alternative assay validation, endocrine disruption, and the US-NAS report on toxicity testing in the twenty-first century have provided directionality to these developments. The reductionistic nature of individual alternative assays requires that they be combined in a testing strategy in order to provide a complete picture of the toxicological profile of a compound. One of the challenges of this innovative approach is the combined interpretation of assay results in terms of toxicologically relevant effects. Computational toxicology aims at providing that integration. In order to progress, we need to follow three steps: (1) Learn from past experience in animal studies and human diseases about critical end points and pathways of toxicity. (2) Design alternative assays for essential mechanisms of toxicity. (3) Build an integrative testing strategy tailored to human hazard assessment using a battery of available alternative tests for critical end points that provides optimal in silico and in vitro filters to upgrade toxicological hazard assessment to the mechanistic level.
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Affiliation(s)
- Aldert H Piersma
- Laboratory for Health Protection Research-National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
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Theunissen PT, Pennings JLA, van Dartel DAM, Robinson JF, Kleinjans JCS, Piersma AH. Complementary Detection of Embryotoxic Properties of Substances in the Neural and Cardiac Embryonic Stem Cell Tests. Toxicol Sci 2012; 132:118-30. [DOI: 10.1093/toxsci/kfs333] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Riebeling C, Hayess K, Peters AK, Steemans M, Spielmann H, Luch A, Seiler AEM. Assaying embryotoxicity in the test tube: current limitations of the embryonic stem cell test (EST) challenging its applicability domain. Crit Rev Toxicol 2012; 42:443-64. [PMID: 22512667 DOI: 10.3109/10408444.2012.674483] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Testing for embryotoxicity in vitro is an attractive alternative to animal experimentation. The embryonic stem cell test (EST) is such a method, and it has been formally validated by the European Centre for the Validation of Alternative Methods. A number of recent studies have underscored the potential of this method. However, the EST performed well below the 78% accuracy expected from the validation study using a new set of chemicals and pharmaceutical compounds, and also of toxicity criteria, tested to enlarge the database of the validated EST as part of the Work Package III of the ReProTect Project funded within the 6th Framework Programme of the European Union. To assess the performance and applicability domain of the EST we present a detailed review of the substances and their effects in the EST being nitrofen, ochratoxin A, D-penicillamine, methylazoxymethanol, lovastatin, papaverine, warfarin, β-aminopropionitrile, dinoseb, furosemide, doxylamine, pravastatin, and metoclopramide. By delineation of the molecular mechanisms of the substances we identify six categories of reasons for misclassifications. Some of these limitations might also affect other in vitro methods assessing embryotoxicity. Substances that fall into these categories need to be included in future validation sets and in validation guidelines for embryotoxicity testing. Most importantly, we suggest conceivable improvements and additions to the EST which will resolve most of the limitations.
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Affiliation(s)
- Christian Riebeling
- German Federal Institute for Risk Assessment (BfR), ZEBET - Alternative Methods to Animal Experiments, Berlin, Germany
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Pennings JLA, Theunissen PT, Piersma AH. An optimized gene set for transcriptomics based neurodevelopmental toxicity prediction in the neural embryonic stem cell test. Toxicology 2012; 300:158-67. [PMID: 22760166 DOI: 10.1016/j.tox.2012.06.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/22/2012] [Accepted: 06/23/2012] [Indexed: 11/16/2022]
Abstract
The murine neural embryonic stem cell test (ESTn) is an in vitro model for neurodevelopmental toxicity testing. Recent studies have shown that application of transcriptomics analyses in the ESTn is useful for obtaining more accurate predictions as well as mechanistic insights. Gene expression responses due to stem cell neural differentiation versus toxicant exposure could be distinguished using the Principal Component Analysis based differentiation track algorithm. In this study, we performed a de novo analysis on combined raw data (10 compounds, 19 exposures) from three previous transcriptomics studies to identify an optimized gene set for neurodevelopmental toxicity prediction in the ESTn. By evaluating predictions of 200,000 randomly selected gene sets, we identified genes which significantly contributed to the prediction reliability. A set of 100 genes was obtained, predominantly involved in (neural) development. Further stringency restrictions resulted in a set of 29 genes that allowed for 84% prediction accuracy (area under the curve 94%). We anticipate these gene sets will contribute to further improve ESTn transcriptomics studies aimed at compound risk assessment.
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Affiliation(s)
- Jeroen L A Pennings
- Laboratory for Health Protection Research (GBO), National Institute for Public Health and the Environment, (RIVM), Bilthoven, The Netherlands.
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de Jong E, van Beek L, Piersma AH. Osteoblast differentiation of murine embryonic stem cells as a model to study the embryotoxic effect of compounds. Toxicol In Vitro 2012; 26:970-8. [PMID: 22683932 DOI: 10.1016/j.tiv.2012.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 05/18/2012] [Accepted: 05/29/2012] [Indexed: 12/23/2022]
Abstract
The embryonic stem cell test (ESTc), in which the effect of chemical compounds on cardiomyocyte differentiation is evaluated, is one of the most studied in vitro alternatives for developmental toxicity testing. Because the assay readout is restricted to a single endpoint of differentiation, compounds that affect alternative differentiation pathways might be overlooked. It has therefore been suggested that the predictive value of the EST may be improved by including alternative differentiation endpoints. The aim of the present study was to evaluate the effect of five teratogenic compounds as well as one non-teratogenic compound on the differentiation of murine embryonic stem cells into osteoblasts (ESTo) and to compare results with those in the classical ESTc. We established an ESTo assay which proved robust, stable and reproducible. In this study, we showed that the evaluated compounds affected osteoblast differentiation both at the level of calcium concentrations in the culture as well as on multiple gene expression. Furthermore, we showed that the effect on calcium concentrations appeared to be primarily mediated by a general apoptotic effect and not by a specific effect on differentiation. The compounds tested showed little difference in their potency in the ESTo as compared to the ESTc. Before a definitive statement can be made regarding the added value of including an osteoblast differentiation endpoint into the EST, more compounds need to be evaluated.
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Affiliation(s)
- Esther de Jong
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
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Theunissen PT, Robinson JF, Pennings JLA, van Herwijnen MH, Kleinjans JCS, Piersma AH. Compound-specific effects of diverse neurodevelopmental toxicants on global gene expression in the neural embryonic stem cell test (ESTn). Toxicol Appl Pharmacol 2012; 262:330-40. [PMID: 22634333 DOI: 10.1016/j.taap.2012.05.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/24/2012] [Accepted: 05/11/2012] [Indexed: 10/28/2022]
Abstract
Alternative assays for developmental toxicity testing are needed to reduce animal use in regulatory toxicology. The in vitro murine neural embryonic stem cell test (ESTn) was designed as an alternative for neurodevelopmental toxicity testing. The integration of toxicogenomic-based approaches may further increase predictivity as well as provide insight into underlying mechanisms of developmental toxicity. In the present study, we investigated concentration-dependent effects of six mechanistically diverse compounds, acetaldehyde (ACE), carbamazepine (CBZ), flusilazole (FLU), monoethylhexyl phthalate (MEHP), penicillin G (PENG) and phenytoin (PHE), on the transcriptome and neural differentiation in the ESTn. All compounds with the exception of PENG altered ESTn morphology (cytotoxicity and neural differentiation) in a concentration-dependent manner. Compound induced gene expression changes and corresponding enriched gene ontology biological processes (GO-BP) were identified after 24h exposure at equipotent differentiation-inhibiting concentrations of the compounds. Both compound-specific and common gene expression changes were observed between subsets of tested compounds, in terms of significance, magnitude of regulation and functionality. For example, ACE, CBZ and FLU induced robust changes in number of significantly altered genes (≥ 687 genes) as well as a variety of GO-BP, as compared to MEHP, PHE and PENG (≤ 55 genes with no significant changes in GO-BP observed). Genes associated with developmentally related processes (embryonic morphogenesis, neuron differentiation, and Wnt signaling) showed diverse regulation after exposure to ACE, CBZ and FLU. In addition, gene expression and GO-BP enrichment showed concentration dependence, allowing discrimination of non-toxic versus toxic concentrations on the basis of transcriptomics. This information may be used to define adaptive versus toxic responses at the transcriptome level.
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Affiliation(s)
- P T Theunissen
- Laboratory for Health Protection Research, National Institute for Public Health and Environment (RIVM), Bilthoven, The Netherlands.
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40
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Ouedraogo M, Baudoux T, Stévigny C, Nortier J, Colet JM, Efferth T, Qu F, Zhou J, Chan K, Shaw D, Pelkonen O, Duez P. Review of current and "omics" methods for assessing the toxicity (genotoxicity, teratogenicity and nephrotoxicity) of herbal medicines and mushrooms. JOURNAL OF ETHNOPHARMACOLOGY 2012; 140:492-512. [PMID: 22386524 DOI: 10.1016/j.jep.2012.01.059] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/31/2012] [Accepted: 01/31/2012] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The increasing use of traditional herbal medicines around the world requires more scientific evidence for their putative harmlessness. To this end, a plethora of methods exist, more or less satisfying. In this post-genome era, recent reviews are however scarce, not only on the use of new "omics" methods (transcriptomics, proteomics, metabonomics) for genotoxicity, teratogenicity, and nephrotoxicity assessment, but also on conventional ones. METHODS The present work aims (i) to review conventional methods used to assess genotoxicity, teratogenicity and nephrotoxicity of medicinal plants and mushrooms; (ii) to report recent progress in the use of "omics" technologies in this field; (iii) to underline advantages and limitations of promising methods; and lastly (iv) to suggest ways whereby the genotoxicity, teratogenicity, and nephrotoxicity assessment of traditional herbal medicines could be more predictive. RESULTS Literature and safety reports show that structural alerts, in silico and classical in vitro and in vivo predictive methods are often used. The current trend to develop "omics" technologies to assess genotoxicity, teratogenicity and nephrotoxicity is promising but most often relies on methods that are still not standardized and validated. CONCLUSION Hence, it is critical that toxicologists in industry, regulatory agencies and academic institutions develop a consensus, based on rigorous methods, about the reliability and interpretation of endpoints. It will also be important to regulate the integration of conventional methods for toxicity assessments with new "omics" technologies.
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Affiliation(s)
- Moustapha Ouedraogo
- Laboratory of Pharmacology and Toxicology, Health Sciences Faculty, University of Ouagadougou, 03 BP 7021 Ouagadougou 03, Burkina Faso. mustapha
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Robinson JF, Pennings JLA, Piersma AH. A review of toxicogenomic approaches in developmental toxicology. Methods Mol Biol 2012; 889:347-371. [PMID: 22669676 DOI: 10.1007/978-1-61779-867-2_22] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Over the past decade, the use of gene expression profiling (i.e., toxicogenomics or transcriptomics) has been established as the vanguard "omics" technology to investigate exposure-induced molecular changes that underlie the development of disease. As this technology quickly advances, researchers are striving to keep pace in grasping the complexity of toxicogenomic response while at the same time determine its applicability for the field of developmental toxicology. Initial studies suggest toxicogenomics to be a promising tool for multiple types of study designs, including exposure-response investigations (dose and duration), chemical classification, and model comparisons. In this review, we examine the use of toxicogenomics in developmental toxicology, discussing biological and technical factors that influence response and interpretation. Additionally, we provide a framework to guide toxicogenomic investigations in the field of developmental toxicology.
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Affiliation(s)
- Joshua F Robinson
- National Institute for Public Health and the Environment-RIVM, Bilthoven, The Netherlands
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Nagano R, Akanuma H, Qin XY, Imanishi S, Toyoshiba H, Yoshinaga J, Ohsako S, Sone H. Multi-parametric profiling network based on gene expression and phenotype data: a novel approach to developmental neurotoxicity testing. Int J Mol Sci 2011; 13:187-207. [PMID: 22312247 PMCID: PMC3269681 DOI: 10.3390/ijms13010187] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 11/14/2011] [Accepted: 11/30/2011] [Indexed: 12/31/2022] Open
Abstract
The establishment of more efficient approaches for developmental neurotoxicity testing (DNT) has been an emerging issue for children’s environmental health. Here we describe a systematic approach for DNT using the neuronal differentiation of mouse embryonic stem cells (mESCs) as a model of fetal programming. During embryoid body (EB) formation, mESCs were exposed to 12 chemicals for 24 h and then global gene expression profiling was performed using whole genome microarray analysis. Gene expression signatures for seven kinds of gene sets related to neuronal development and neuronal diseases were selected for further analysis. At the later stages of neuronal cell differentiation from EBs, neuronal phenotypic parameters were determined using a high-content image analyzer. Bayesian network analysis was then performed based on global gene expression and neuronal phenotypic data to generate comprehensive networks with a linkage between early events and later effects. Furthermore, the probability distribution values for the strength of the linkage between parameters in each network was calculated and then used in principal component analysis. The characterization of chemicals according to their neurotoxic potential reveals that the multi-parametric analysis based on phenotype and gene expression profiling during neuronal differentiation of mESCs can provide a useful tool to monitor fetal programming and to predict developmentally neurotoxic compounds.
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Affiliation(s)
- Reiko Nagano
- Health Risk Research Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan; E-Mails: (R.N.); (H.A.); (X.-Y.Q.); (H.T.)
| | - Hiromi Akanuma
- Health Risk Research Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan; E-Mails: (R.N.); (H.A.); (X.-Y.Q.); (H.T.)
| | - Xian-Yang Qin
- Health Risk Research Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan; E-Mails: (R.N.); (H.A.); (X.-Y.Q.); (H.T.)
- Department of Environmental Studies, Graduate School of Frontier Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 270-8563, Japan; E-Mail:
| | - Satoshi Imanishi
- Center for Disease Biology and Integrative Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan; E-Mails: (S.I.); (S.O.)
| | - Hiroyoshi Toyoshiba
- Health Risk Research Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan; E-Mails: (R.N.); (H.A.); (X.-Y.Q.); (H.T.)
| | - Jun Yoshinaga
- Department of Environmental Studies, Graduate School of Frontier Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 270-8563, Japan; E-Mail:
| | - Seiichiroh Ohsako
- Center for Disease Biology and Integrative Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan; E-Mails: (S.I.); (S.O.)
| | - Hideko Sone
- Health Risk Research Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan; E-Mails: (R.N.); (H.A.); (X.-Y.Q.); (H.T.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-29-850-2464; Fax: +81-29-850-2546
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Baek DH, Kim TG, Lim HK, Kang JW, Seong SK, Choi SE, Lim SY, Park SH, Nam BH, Kim EH, Kim MS, Park KL. Embryotoxicity assessment of developmental neurotoxicants using a neuronal endpoint in the embryonic stem cell test. J Appl Toxicol 2011; 32:617-26. [PMID: 22131109 DOI: 10.1002/jat.1747] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 07/27/2011] [Accepted: 08/31/2011] [Indexed: 11/05/2022]
Abstract
The embryonic stem cell test (EST) is a validated in vitro embryotoxicity test; however, as the inhibition of cardiac differentiation alone is used as a differentiation endpoint in the EST, it may not be a useful test to screen embryotoxic chemicals that affect the differentiation of noncardiac tissues. Previously, methylmercury (MeHg), cadmium and arsenic compounds, which are heavy metals that induce developmental neurotoxicity in vivo, were misclassified as nonembryotoxic with the EST. The aim of this study was to improve the EST to correctly screen such developmental neurotoxicants. We developed a neuronal endpoint (Tuj-1 ID₅₀) using flow cytometry analysis of Tuj-1-positive cells to screen developmental neurotoxicants (MeHg, valproic acid, sodium arsenate and sodium arsenite) correctly using an adherent monoculture differentiation method. Using Tuj-1 ID₅₀ in the EST instead of cardiac ID₅₀, all of the tested chemicals were classified as embryotoxic, while the negative controls were correctly classified as nonembryotoxic. To support the validity of Tuj-1 ID₅₀) , we compared the results from two experimenters who independently tested MeHg using our modified EST. An additional neuronal endpoint (MAP2 ID₅₀), obtained by analyzing the relative quantity of MAP2 mRNA, was used to classify the same chemicals. There were no significant differences in the three endpoint values of the two experimenters or in the classification results, except for isoniazid. In conclusion, our results indicate that Tuj-1 ID₅₀ can be used as a surrogate endpoint of the traditional EST to screen developmental neurotoxicants correctly and it can also be applied to other chemicals.
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Affiliation(s)
- Dae Hyun Baek
- Center for Drug Development Assistance, National Institute of Food and Drug Safety Evaluation, Korea Food and Drug Administration, Cheongwon-gun, Chungcheongbuk-do 363-951, South Korea
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Louisse J, Verwei M, Woutersen RA, Blaauboer BJ, Rietjens IMCM. Towardin vitrobiomarkers for developmental toxicity and their extrapolation to thein vivosituation. Expert Opin Drug Metab Toxicol 2011; 8:11-27. [DOI: 10.1517/17425255.2012.639762] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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45
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Theunissen PT, Robinson JF, Pennings JLA, de Jong E, Claessen SMH, Kleinjans JCS, Piersma AH. Transcriptomic concentration-response evaluation of valproic acid, cyproconazole, and hexaconazole in the neural embryonic stem cell test (ESTn). Toxicol Sci 2011; 125:430-8. [PMID: 22045034 DOI: 10.1093/toxsci/kfr293] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Alternative developmental toxicity assays are urgently needed to reduce animal use in regulatory developmental toxicology. We previously designed an in vitro murine neural embryonic stem cell test (ESTn) as a model for neurodevelopmental toxicity testing (Theunissen et al., 2010). Toxicogenomic approaches have been suggested for incorporation into the ESTn to further increase predictivity and to provide mechanistic insights. Therefore, in this study, using a transcriptomic approach, we investigated the concentration-dependent effects of three known (neuro) developmental toxicants, two triazoles, cyproconazole (CYP) and hexaconazole (HEX), and the anticonvulsant valproic acid (VPA). Compound effects on gene expression during neural differentiation and corresponding regulated gene ontology (GO) terms were identified after 24 h of exposure in relation to morphological changes on day 11 of culture. Concentration-dependent responses on individual gene expression and on biological processes were determined for each compound, providing information on mechanism and concentration-response characteristics. All compounds caused enrichment of the embryonic development process. CYP and VPA but not HEX significantly enriched the neuron development process. Furthermore, specific responses for triazole compounds and VPA were observed within the GO-term sterol metabolic process. The incorporation of transcriptomics in the ESTn was shown to enable detection of effects, which precede morphological changes and provide a more sensitive measure of concentration-dependent effects as compared with classical morphological assessments. Furthermore, mechanistic insight can be instrumental in the extrapolation of effects in the ESTn to human hazard assessment.
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Affiliation(s)
- Peter T Theunissen
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), 3720 BA Bilthoven, The Netherlands.
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Robinson JF, Theunissen PT, van Dartel DA, Pennings JL, Faustman EM, Piersma AH. Comparison of MeHg-induced toxicogenomic responses across in vivo and in vitro models used in developmental toxicology. Reprod Toxicol 2011; 32:180-8. [DOI: 10.1016/j.reprotox.2011.05.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 05/12/2011] [Accepted: 05/13/2011] [Indexed: 12/14/2022]
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Inselman AL, Hansen DK, Lee HY, Nakamura N, Ning B, Monteiro JP, Varma V, Kaput J. Assessment of research models for testing gene-environment interactions. Eur J Pharmacol 2011; 668 Suppl 1:S108-16. [PMID: 21816149 DOI: 10.1016/j.ejphar.2011.05.084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/16/2011] [Accepted: 05/22/2011] [Indexed: 12/16/2022]
Abstract
Throughout the last century, possible effects of exposure to toxicants, nutrients or drugs were examined primarily by studies of groups or populations. Individual variation in responses was acknowledged but could not be analyzed due to lack of information or tools to analyze individual genetic make-ups and lifestyle factors such as diet and activity. The Human Genome, Haplotype Map, 1000Genomes, and Human Variome Projects are identifying and cataloging the variation found within humans. Advances in DNA sequencing technologies will soon permit the characterization of individual genomes in clinical and basic research studies, thus allowing associations to be made between an individual genotype and the response to a particular exposure. Such knowledge and tools have generated a significant challenge for scientists: to design and conduct research studies that account for individual genetic variation. However, before these studies are done in humans, they will be performed in various in vivo and in vitro models. The advantages and disadvantages of some of the model test systems that are being used or developed in relation to individual genetic make-up and responses to xenobiotics are discussed.
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Affiliation(s)
- Amy L Inselman
- Division of Personalized Nutrition and Medicine, NCTR/FDA, 3900 NCTR Rd., Jefferson, AR 72079, United States.
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48
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Theunissen PT, Pennings JLA, Robinson JF, Claessen SMH, Kleinjans JCS, Piersma AH. Time-Response Evaluation by Transcriptomics of Methylmercury Effects on Neural Differentiation of Murine Embryonic Stem Cells. Toxicol Sci 2011; 122:437-47. [DOI: 10.1093/toxsci/kfr134] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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van Dartel DAM, Piersma AH. The embryonic stem cell test combined with toxicogenomics as an alternative testing model for the assessment of developmental toxicity. Reprod Toxicol 2011; 32:235-44. [PMID: 21575713 DOI: 10.1016/j.reprotox.2011.04.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 04/20/2011] [Accepted: 04/29/2011] [Indexed: 01/15/2023]
Abstract
One of the most studied in vitro alternative testing methods for identification of developmental toxicity is the embryonic stem cell test (EST). Although the EST has been formally validated, the applicability domain as well as the predictability of the model needs further study to allow successful implementation of the EST as an alternative testing method in regulatory toxicity testing. Genomics technologies have already provided a proof of principle of their value in identification of toxicants such as carcinogenic compounds. Also within the EST, gene expression profiling has shown its value in the identification of developmental toxicity and in the evaluation of factors critical for risk assessment, such as dose and time responses. It is expected that the implementation of genomics into the EST will provide a more detailed end point evaluation as compared to the classical morphological scoring of differentiation cultures. Therefore, genomics may contribute to improvement of the EST, both in terms of definition of its applicability domain as well as its predictive capacity. In the present review, we present the progress that has been made with regard to the prediction of developmental toxicity using the EST combined with transcriptomics. Furthermore, we discuss the developments of additional aspects required for further optimization of the EST, including kinetics, the use of human embryonic stem cells (ESC) and computational toxicology. Finally, the current and future use of the EST model for prediction of developmental toxicity in testing strategies and in regulatory toxicity evaluations is discussed.
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Affiliation(s)
- Dorien A M van Dartel
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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50
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Adler S, Basketter D, Creton S, Pelkonen O, van Benthem J, Zuang V, Andersen KE, Angers-Loustau A, Aptula A, Bal-Price A, Benfenati E, Bernauer U, Bessems J, Bois FY, Boobis A, Brandon E, Bremer S, Broschard T, Casati S, Coecke S, Corvi R, Cronin M, Daston G, Dekant W, Felter S, Grignard E, Gundert-Remy U, Heinonen T, Kimber I, Kleinjans J, Komulainen H, Kreiling R, Kreysa J, Leite SB, Loizou G, Maxwell G, Mazzatorta P, Munn S, Pfuhler S, Phrakonkham P, Piersma A, Poth A, Prieto P, Repetto G, Rogiers V, Schoeters G, Schwarz M, Serafimova R, Tähti H, Testai E, van Delft J, van Loveren H, Vinken M, Worth A, Zaldivar JM. Alternative (non-animal) methods for cosmetics testing: current status and future prospects-2010. Arch Toxicol 2011; 85:367-485. [PMID: 21533817 DOI: 10.1007/s00204-011-0693-2] [Citation(s) in RCA: 358] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/03/2011] [Indexed: 01/09/2023]
Abstract
The 7th amendment to the EU Cosmetics Directive prohibits to put animal-tested cosmetics on the market in Europe after 2013. In that context, the European Commission invited stakeholder bodies (industry, non-governmental organisations, EU Member States, and the Commission's Scientific Committee on Consumer Safety) to identify scientific experts in five toxicological areas, i.e. toxicokinetics, repeated dose toxicity, carcinogenicity, skin sensitisation, and reproductive toxicity for which the Directive foresees that the 2013 deadline could be further extended in case alternative and validated methods would not be available in time. The selected experts were asked to analyse the status and prospects of alternative methods and to provide a scientifically sound estimate of the time necessary to achieve full replacement of animal testing. In summary, the experts confirmed that it will take at least another 7-9 years for the replacement of the current in vivo animal tests used for the safety assessment of cosmetic ingredients for skin sensitisation. However, the experts were also of the opinion that alternative methods may be able to give hazard information, i.e. to differentiate between sensitisers and non-sensitisers, ahead of 2017. This would, however, not provide the complete picture of what is a safe exposure because the relative potency of a sensitiser would not be known. For toxicokinetics, the timeframe was 5-7 years to develop the models still lacking to predict lung absorption and renal/biliary excretion, and even longer to integrate the methods to fully replace the animal toxicokinetic models. For the systemic toxicological endpoints of repeated dose toxicity, carcinogenicity and reproductive toxicity, the time horizon for full replacement could not be estimated.
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Affiliation(s)
- Sarah Adler
- Centre for Documentation and Evaluation of Alternatives to Animal Experiments (ZEBET), Federal Institute for Risk Assessment (BfR), Berlin, Germany
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