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Lewis RW, Andrus AK, Arroyo J, Brescia S, Botham PA, Corvaro M, Daston GP, Hofmann T, Rodriguez C, Sewell F, van Ravenzwaay B, Wiench K, Marty S. Considerations for the development of guidance on dose level selection for developmental and reproductive toxicity studies. Regul Toxicol Pharmacol 2024; 148:105585. [PMID: 38403008 DOI: 10.1016/j.yrtph.2024.105585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/06/2024] [Accepted: 02/18/2024] [Indexed: 02/27/2024]
Abstract
In 2022, the European Chemicals Agency issued advice on the selection of high dose levels for developmental and reproductive toxicity (DART) studies indicating that the highest dose tested should aim to induce clear evidence of reproductive toxicity without excessive toxicity and severe suffering in parental animals. In addition, a recent publication advocated that a 10% decrease in body weight gain should be replaced with a 10% decrease in bodyweight as a criterion for dose adequacy. Experts from the European Centre for Ecotoxicology and Toxicology of Chemicals evaluated these recent developments and their potential impact on study outcomes and interpretation and identified that the advice was not aligned with OECD test guidelines or with humane endpoints guidance. Furthermore, data analysis from DART studies indicated that a 10% decrease in maternal body weight during gestation equates to a 25% decrease in body weight gain, which differs from the consensus of experts at a 2010 ILSI/HESI workshop. Dose selection should be based on a biological approach that considers a range of other factors. Excessive dose levels that cause frank toxicity and overwhelm homeostasis should be avoided as they can give rise to effects that are not relevant to human health assessments.
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Affiliation(s)
- R W Lewis
- Regulatory Science Associates, Inverkip, Glasgow, Scotland, UK
| | - A K Andrus
- The Dow Chemical Company, Midland, MI, USA
| | | | - S Brescia
- Health & Safety Executive, Chemicals Regulation Division (CRD), Bootle, UK
| | | | - M Corvaro
- Corteva Agriscience Italia S.r.l., Rome, Italy
| | | | | | | | - F Sewell
- National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK.
| | | | | | - S Marty
- The Dow Chemical Company, Midland, MI, USA
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Ellison CA, Arnot JA, Felter SP, Daston GP, Becker RA, Toose L, Armitage JM, Sangion A, Looky A, Brown TN, Li L. Letter to the editor regarding recent publication titled "Developing an internal threshold of toxicological concern (iTTC)" by Arnot et al. (2022). J Expo Sci Environ Epidemiol 2023; 33:840-841. [PMID: 37443297 DOI: 10.1038/s41370-023-00571-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/01/2023] [Accepted: 06/12/2023] [Indexed: 07/15/2023]
Affiliation(s)
- Corie A Ellison
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA.
| | - Jon A Arnot
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Susan P Felter
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA
| | - George P Daston
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA
| | | | - Liisa Toose
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
| | | | - Alessandro Sangion
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | | | - Trevor N Brown
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
| | - Li Li
- School of Public Health, University of Nevada Reno, Reno, NV, USA
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Wu S, Ellison C, Naciff J, Karb M, Obringer C, Yan G, Shan Y, Smith A, Wang X, Daston GP. Structure-activity relationship read-across and transcriptomics for branched carboxylic acids. Toxicol Sci 2023; 191:343-356. [PMID: 36583546 DOI: 10.1093/toxsci/kfac139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The purpose of this study was to use chemical similarity evaluations, transcriptional profiling, in vitro toxicokinetic data, and physiologically based pharmacokinetic (PBPK) models to support read-across for a series of branched carboxylic acids using valproic acid (VPA), a known developmental toxicant, as a comparator. The chemicals included 2-propylpentanoic acid (VPA), 2-ethylbutanoic acid, 2-ethylhexanoic acid (EHA), 2-methylnonanoic acid, 2-hexyldecanoic acid, 2-propylnonanoic acid (PNA), dipentyl acetic acid or 2-pentylheptanoic acid, octanoic acid (a straight chain alkyl acid), and 2-ethylhexanol. Transcriptomics was evaluated in 4 cell types (A549, HepG2, MCF7, and iCell cardiomyocytes) 6 h after exposure to 3 concentrations of the compounds, using the L1000 platform. The transcriptional profiling data indicate that 2- or 3-carbon alkyl substituents at the alpha position of the carboxylic acid (EHA and PNA) elicit a transcriptional profile similar to the one elicited by VPA. The transcriptional profile is different for the other chemicals tested, which provides support for limiting read-across from VPA to much shorter and longer acids. Molecular docking models for histone deacetylases, the putative target of VPA, provide a possible mechanistic explanation for the activity cliff elucidated by transcriptomics. In vitro toxicokinetic data were utilized in a PBPK model to estimate internal dosimetry. The PBPK modeling data show that as the branched chain increases, predicted plasma Cmax decreases. This work demonstrates how transcriptomics and other mode of action-based methods can improve read-across.
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Affiliation(s)
- Shengde Wu
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Corie Ellison
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Jorge Naciff
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Michael Karb
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Cindy Obringer
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Gang Yan
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Yuqing Shan
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Alex Smith
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Xiaohong Wang
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - George P Daston
- Global Product Stewardship, The Procter and Gamble Company, Mason, Ohio 45040, USA
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Naciff JM, Shan YK, Wang X, Daston GP. Article title: Transcriptional profiling efficacy to define biological activity similarity for cosmetic ingredients' safety assessment based on next-generation read-across. Front Toxicol 2022; 4:1082222. [PMID: 36618549 PMCID: PMC9811170 DOI: 10.3389/ftox.2022.1082222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
The objective of this work was to use transcriptional profiling to assess the biological activity of structurally related chemicals to define their biological similarity and with that, substantiate the validity of a read-across approach usable in risk assessment. Two case studies are presented, one with 4 short alkyl chain parabens: methyl (MP), ethyl (EP), butyl (BP), and propylparaben (PP), as well as their main metabolite, p-hydroxybenzoic acid (pHBA) with the assumption that propylparaben was the target chemical; and a second one with caffeine and its main metabolites theophylline, theobromine and paraxanthine where CA was the target chemical. The comprehensive transcriptional response of MCF7, HepG2, A549 and ICell cardiomyocytes was evaluated (TempO-Seq) after exposure to vehicle-control, each paraben or pHBA, CA or its metabolites, at 3 non-cytotoxic concentrations, for 6 h. Differentially expressed genes (FDR ≥0.05, and fold change ±1.2≥) were identified for each chemical, at each concentration, and used to determine similarities. Each of the chemicals is able to elicit changes in the expression of a number of genes, as compared to controls. Importantly, the transcriptional profile elicited by each of the parabens shares a high degree of similarity across the group. The highest number of genes commonly affected was between butylparaben and PP. The transcriptional profile of the parabens is similar to the one elicited by estrogen receptor agonists, with BP being the closest structural and biological analogue for PP. In the CA case, the transcriptional profile elicited of all four methylxanthines had a high degree of similarity across the cell types, with CA and theophylline being the most active. The most robust response was obtained in the cardiomyocytes with the highest transcriptional profile similarity between CA and TP. The transcriptional profile of the methylxanthines is similar to the one elicited by inhibitors of phosphatidylinositol 3-kinase as well as other kinase inhibitors. Overall, our results support the approach of incorporating transcriptional profiling in well-designed in vitro tests as one robust stream of data to support biological similarity driven read-across procedures and strengthening the traditional structure-based approaches useful in risk assessment.
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De Abrew KN, Natoli T, Lester CC, Wang X, Shobair M, Subramanian A, Daston GP. A New Approach Methodology (NAM) Based Assessment of Butylated hydroxytoluene (BHT) for Endocrine Disruption Potential. Toxicol Sci 2022; 190:227-241. [PMID: 36161505 DOI: 10.1093/toxsci/kfac099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Butylated hydroxytoluene (BHT) is a synthetic antioxidant widely used in many industrial sectors. BHT is a well-studied compound for which there are many favorable regulatory decisions. However, a recent opinion by French Agency for Food, Environmental and Occupational Health and Safety (ANSES) hypothesizes a role for BHT in endocrine disruption (ANSES 2021). This opinion is based on observations in mostly rat studies where changes to thyroid physiology is observed. While enzymatic induction of Cytochrome P450 mediated thyroid hormone catabolism has been proposed as a mechanism, a causal relationship has not been proven. Other evidence proposed in the document include a read across argument to butylated hydroxyanisole (BHA), another Community Rolling Action Plan (CoRAP) -listed substance with endocrine disruption concerns. We tested the hypothesis that BHT is an endocrine disruptor by using a Next Generation Risk Assessment (NGRA) method. Four different cell lines: A549, HCC1428, HepG2 and MCF7 were treated with BHT and a series of BHT analogs at 5 different concentrations, RNA was isolated from cell extracts and run on the L1000 gene array platform. A toxicogenomics-based assessment was performed by comparing BHT's unique genomic signature to a large external database containing signatures of other compounds (including many known endocrine disruptors) to identify if any endocrine disruption-related modes of action (MoAs) are prevalent among BHT and other compounds with similar genomic signatures. In addition, we performed a toxicogenomics-based structure activity relationship (SAR) assessment of BHT and a series of structurally similar analogues to understand if endocrine disruption is a relevant MoA for chemicals that are considered suitable analogs to BHT using the P&G read across framework (Wu et al., 2010). Neither BHT nor any of its analogs connected to compounds that had endocrine activity for estrogens, androgens, thyroid, or steroidogenesis activity.
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Affiliation(s)
- K Nadira De Abrew
- Fabric and Home Care Innovation Center, The Procter & Gamble Company, 5299 Spring Grove Avenue, Cincinnati, OH 45217, USA
| | - Ted Natoli
- Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142
| | - Cathy C Lester
- Mason Business Center, The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH 45040, USA
| | - Xiaohong Wang
- Mason Business Center, The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH 45040, USA
| | - Mahmoud Shobair
- Mason Business Center, The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH 45040, USA
| | - Arvind Subramanian
- Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142
| | - George P Daston
- Mason Business Center, The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH 45040, USA
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [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
A systematic scoping review of the literature evaluated the embryonic stem cell test (EST). 1533 publications included 18 publications testing 10 or more compounds in human or mouse EST. Selected case examples included 5-fluorouracil, thalidomide, and caffeine. Applicability, limitations, and recommendations for further work are discussed.
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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Daston GP, Mahony C, Thomas RS, Vinken M. Assessing Safety without Animal Testing: The Road Ahead. Toxicol Sci 2022; 187:214-218. [PMID: 35357465 DOI: 10.1093/toxsci/kfac039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | - Russell S Thomas
- US Environmental Protection Agency, Research Triangle Park, NC, USA
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Knudsen TB, Fitzpatrick SC, De Abrew KN, Birnbaum LS, Chappelle A, Daston GP, Dolinoy DC, Elder A, Euling S, Faustman EM, Fedinick KP, Franzosa JA, Haggard DE, Haws L, Kleinstreuer NC, Buck Louis GM, Mendrick DL, Rudel R, Saili KS, Schug TT, Tanguay RL, Turley AE, Wetmore BA, White KW, Zurlinden TJ. FutureTox IV Workshop Summary: Predictive Toxicology for Healthy Children. Toxicol Sci 2021; 180:198-211. [PMID: 33555348 PMCID: PMC8041457 DOI: 10.1093/toxsci/kfab013] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
FutureTox IV, a Society of Toxicology Contemporary Concepts in Toxicology workshop, was held in November 2018. Building upon FutureTox I, II, and III, this conference focused on the latest science and technology for in vitro profiling and in silico modeling as it relates to predictive developmental and reproductive toxicity (DART). Publicly available high-throughput screening data sets are now available for broad in vitro profiling of bioactivities across large inventories of chemicals. Coupling this vast amount of mechanistic data with a deeper understanding of molecular embryology and post-natal development lays the groundwork for using new approach methodologies (NAMs) to evaluate chemical toxicity, drug efficacy, and safety assessment for embryo-fetal development. NAM is a term recently adopted in reference to any technology, methodology, approach, or combination thereof that can be used to provide information on chemical hazard and risk assessment to avoid the use of intact animals (U.S. Environmental Protection Agency [EPA], Strategic plan to promote the development and implementation of alternative test methods within the tsca program, 2018, https://www.epa.gov/sites/production/files/2018-06/documents/epa_alt_strat_plan_6-20-18_clean_final.pdf). There are challenges to implementing NAMs to evaluate chemicals for developmental toxicity compared with adult toxicity. This forum article reviews the 2018 workshop activities, highlighting challenges and opportunities for applying NAMs for adverse pregnancy outcomes (eg, preterm labor, malformations, low birth weight) as well as disorders manifesting postnatally (eg, neurodevelopmental impairment, breast cancer, cardiovascular disease, fertility). DART is an important concern for different regulatory statutes and test guidelines. Leveraging advancements in such approaches and the accompanying efficiencies to detecting potential hazards to human development are the unifying concepts toward implementing NAMs in DART testing. Although use of NAMs for higher level regulatory decision making is still on the horizon, the conference highlighted novel testing platforms and computational models that cover multiple levels of biological organization, with the unique temporal dynamics of embryonic development, and novel approaches for estimating toxicokinetic parameters essential in supporting in vitro to in vivo extrapolation.
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Affiliation(s)
- Thomas B Knudsen
- U.S. Environmental Protection Agency, ORD, Research Triangle Park, North Carolina, USA
| | | | | | - Linda S Birnbaum
- National Institute of Environmental Health Science, NIH, Research Triangle Park, North Carolina, USA
| | - Anne Chappelle
- Chappelle Toxicology Consulting, LLC, Chadds Ford, Pennsylvania, USA
| | | | | | - Alison Elder
- University of Rochester, Rochester, New York, USA
| | - Susan Euling
- U.S. Environmental Protection Agency, Office of Children’s Health Protection, Washington, District of Columbia, USA
| | | | | | - Jill A Franzosa
- U.S. Environmental Protection Agency, ORD, Research Triangle Park, North Carolina, USA
| | - Derik E Haggard
- U.S. Environmental Protection Agency, ORD, Research Triangle Park, North Carolina, USA
- Oak Ridge Institute for Science and Education (ORISE);, Texas, USA
| | | | | | | | - Donna L Mendrick
- U.S. Food and Drug Administration, NCTR, Silver Spring, Maryland, USA
| | | | - Katerine S Saili
- U.S. Environmental Protection Agency, ORD, Research Triangle Park, North Carolina, USA
| | - Thaddeus T Schug
- National Institute of Environmental Health Science, NIH, Research Triangle Park, North Carolina, USA
| | | | | | - Barbara A Wetmore
- U.S. Environmental Protection Agency, ORD, Research Triangle Park, North Carolina, USA
| | - Kimberly W White
- American Chemistry Council, Washington, District of Columbia, USA
| | - Todd J Zurlinden
- U.S. Environmental Protection Agency, ORD, Research Triangle Park, North Carolina, USA
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VanderMolen KM, Naciff JM, Kennedy K, Otto-Bruc A, Shan Y, Wang X, Daston GP, Mahony C. Incorporation of in vitro techniques for botanicals dietary supplement safety assessment - Towards evaluation of developmental and reproductive toxicity (DART). Food Chem Toxicol 2020; 144:111539. [PMID: 32645467 DOI: 10.1016/j.fct.2020.111539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/22/2022]
Abstract
As complex mixtures, botanicals present unique challenges when assessing safe use, particularly when endpoint gaps exist that cannot be fully resolved by existing toxicological literature. Here we explore in vitro gene expression as well receptor binding and enzyme activity as alternative assays to inform on developmental and reproductive toxicity (DART) relevant modes of action, since DART data gaps are common for botanicals. Specifically, botanicals suspected to have DART effects, in addition to those with a significant history of use, were tested in these assays. Gene expression changes in a number of different cell types were analysed using the connectivity mapping approach (CMap) to identify modes of action through a functional read across approach. Taken together with ligand affinity data obtained using a set of molecular targets customised towards known DART relevant modes of action, it was possible to inform DART risk using functional analogues, potency comparisons and a margin of internal exposure approach.
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Affiliation(s)
- Karen M VanderMolen
- Procter & Gamble, Mason Business Centre, 8700 Mason - Montgomery Rd, Mason, OH, 45040, USA
| | - Jorge M Naciff
- Procter & Gamble, Mason Business Centre, 8700 Mason - Montgomery Rd, Mason, OH, 45040, USA
| | - Kevin Kennedy
- Eurofins Discovery, Bioanalytical, St Charles, MO, USA
| | | | - Yuqing Shan
- Procter & Gamble, Mason Business Centre, 8700 Mason - Montgomery Rd, Mason, OH, 45040, USA
| | - Xiaohong Wang
- Procter & Gamble, Mason Business Centre, 8700 Mason - Montgomery Rd, Mason, OH, 45040, USA
| | - George P Daston
- Procter & Gamble, Mason Business Centre, 8700 Mason - Montgomery Rd, Mason, OH, 45040, USA
| | - Catherine Mahony
- Procter & Gamble Technical Centre, Whitehall Lane, Egham, Surrey, TW20 9AW, UK.
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Mahony C, Ashton RS, Birk B, Boobis AR, Cull T, Daston GP, Ewart L, Knudsen TB, Manou I, Maurer-Stroh S, Margiotta-Casaluci L, Müller BP, Nordlund P, Roberts RA, Steger-Hartmann T, Vandenbossche E, Viant MR, Vinken M, Whelan M, Zvonimir Z, Cronin MTD. New ideas for non-animal approaches to predict repeated-dose systemic toxicity: Report from an EPAA Blue Sky Workshop. Regul Toxicol Pharmacol 2020; 114:104668. [PMID: 32335207 DOI: 10.1016/j.yrtph.2020.104668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/10/2020] [Accepted: 04/17/2020] [Indexed: 02/09/2023]
Abstract
The European Partnership for Alternative Approaches to Animal Testing (EPAA) convened a 'Blue Sky Workshop' on new ideas for non-animal approaches to predict repeated-dose systemic toxicity. The aim of the Workshop was to formulate strategic ideas to improve and increase the applicability, implementation and acceptance of modern non-animal methods to determine systemic toxicity. The Workshop concluded that good progress is being made to assess repeated dose toxicity without animals taking advantage of existing knowledge in toxicology, thresholds of toxicological concern, adverse outcome pathways and read-across workflows. These approaches can be supported by New Approach Methodologies (NAMs) utilising modern molecular technologies and computational methods. Recommendations from the Workshop were based around the needs for better chemical safety assessment: how to strengthen the evidence base for decision making; to develop, standardise and harmonise NAMs for human toxicity; and the improvement in the applicability and acceptance of novel techniques. "Disruptive thinking" is required to reconsider chemical legislation, validation of NAMs and the opportunities to move away from reliance on animal tests. Case study practices and data sharing, ensuring reproducibility of NAMs, were viewed as crucial to the improvement of non-animal test approaches for systemic toxicity.
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Affiliation(s)
| | - Randolph S Ashton
- Department of Biomedical Engineering & Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, 53715, USA.
| | - Barbara Birk
- BASF SE, Experimental Toxicology and Ecology, Carl-Bosch-Straβe 38, 67056, Ludwigshafen, Germany.
| | - Alan R Boobis
- National Heart & Lung Institute, Imperial College London, London, W12 0NN, UK.
| | - Tom Cull
- Unilever, Colworth Science Park, Sharnbrook, Bedford, MK44 1LQ, UK.
| | - George P Daston
- Mason Business Center, The Procter & Gamble Company, Cincinnati, OH, 45040, USA.
| | - Lorna Ewart
- Veroli Consulting Limited, Cambridge, UK; Emulate Inc, 27 Dry Dock Avenue, Boston, MA, 02210, USA.
| | - Thomas B Knudsen
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, NC, 27711, USA.
| | - Irene Manou
- European Partnership for Alternative Approaches to Animal Testing (EPAA) Industry Secretariat, Belgium.
| | - Sebastian Maurer-Stroh
- Innovations in Chemical and Food Safety, Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01 Matrix, Singapore, 138671, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore.
| | | | | | - Pär Nordlund
- Department of Oncology and Pathology, Karolinska Institutet, 17177, Stockholm, Sweden; Institute of Molecular and Cellular Biology, A*STAR, 61 Biopolis Drive, 138673, Singapore.
| | - Ruth A Roberts
- School of Chemistry, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Thomas Steger-Hartmann
- Investigational Toxicology, Bayer AG, Pharmaceuticals, Müllerstraβe 178, 13353, Berlin, Germany.
| | | | - Mark R Viant
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
| | - Maurice Whelan
- European Commission, Joint Research Centre (JRC), Italy.
| | - Zvonar Zvonimir
- European Partnership for Alternative Approaches to Animal Testing (EPAA) Industry Secretariat, Belgium.
| | - Mark T D Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
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Affiliation(s)
- Calvin C Willhite
- Risk Sciences International, Ottawa, Ontario, Canada; R. Samuel McLaughlin Center for Population Health Risk Assessment, University of Ottawa, Ottawa K1P 5J6, Canada
| | - George P Daston
- Victor Mills Society Research Fellow, Procter & Gamble Company, Mason, OH 45040, USA.
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12
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De Abrew KN, Shan YK, Wang X, Krailler JM, Kainkaryam RM, Lester CC, Settivari RS, LeBaron MJ, Naciff JM, Daston GP. Use of connectivity mapping to support read across: A deeper dive using data from 186 chemicals, 19 cell lines and 2 case studies. Toxicology 2019; 423:84-94. [DOI: 10.1016/j.tox.2019.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/30/2019] [Accepted: 05/19/2019] [Indexed: 01/21/2023]
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13
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Daston GP, Beekhuijzen M. Is omphalocele a non-specific malformation in New Zealand White rabbits? Reprod Toxicol 2018; 78:29-39. [PMID: 29550350 DOI: 10.1016/j.reprotox.2018.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/09/2018] [Accepted: 03/13/2018] [Indexed: 10/17/2022]
Abstract
We evaluated the incidence of omphalocele, a malformation that occurs sporadically in many studies. We assembled data on external malformations using all treatment groups from every study published in three major journals over the past 35 years using New Zealand White rabbits. Fifty-eight papers were included: 4905 litters and 36,977 fetuses. Omphalocele was reported in 43% and was among the most common defects, occurring at a rate of 1.10% (litter) and 0.16% (fetus). The defect did not appear to be treatment-related, although it may have been in two studies, based on rate and dose-responsiveness. Removing these two studies from the analysis, the defect was still prevalent (0.77% litter, 0.11% fetal incidence). Three studies evaluated the effects of food restriction and omphalocele was observed with food restriction in two of them, suggesting that decreased maternal weight gain or food consumption may be causal. Otherwise, it appears to be spontaneous and common.
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Daston GP, Tuan RS, Vekemans M. A unified birth defects research. Birth Defects Res 2017; 109:7. [PMID: 27905204 DOI: 10.1002/bdra.23595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 10/13/2016] [Indexed: 11/07/2022]
Affiliation(s)
| | - Rocky S Tuan
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Naciff JM, Daston GP. Toxicogenomic Approach to Endocrine Disrupters: Identification of a Transcript Profile Characteristic of Chemicals with Estrogenic Activity. Toxicol Pathol 2016; 32 Suppl 2:59-70. [PMID: 15503665 DOI: 10.1080/01926230490463812] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Public concerns have been raised in recent years over the possible adverse effects that may result from exposure to chemicals in the environment that have the potential to interfere with the normal function of the endocrine system in wildlife and humans (“endocrine disrupters”). Regulations have been established that require the testing of pesticides used in food crops and drinking water contaminants, for estrogenicity and other hormonal activities. In the United States, the U.S. EPA proposed the Endocrine Disrupter Screening Program, which consists of a Tier 1 screening battery of tests that is designed to identify chemicals capable of interacting with various hormonal systems, and different Tier 2 testing assays that are designed to verify and broaden the Tier 1 results. We identify 2 main problems with this approach: (1) the fact that the developmental stages that are the most susceptible to endocrine disruption are not represented in the screening tier, mainly because developmental effects tend to be latent, and there is no way to economically screen in developing models; and (2) the expense to screen each chemical to be included in this program. Thus, the need arises for an accurate, rapid, and cost effective method for assessing the potential endocrine activity of multiple chemicals during development. We hypothesize that the largely latent developmental effects of some endocrine disruptors are preceded by immediate changes in gene expression in the embryo and fetus. Therefore, an approach to assess the potential estrogenic (and other steroid hormonal) activity of different compounds is to identify those patterns of gene expression elicited in a tissue/organ exposed to these particular classes of chemicals. In this paper, the potential utility of such an approach for screening and better understanding of mechanism of action for specific chemicals with endocrine disrupter activities is presented, using as an example chemicals with estrogenic activity.
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Affiliation(s)
- Jorge M Naciff
- Miami Valley Laboratories, The Procter and Gamble Company, Cincinnati, Ohio 45253, USA.
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Juberg DR, Knudsen TB, Sander M, Beck NB, Faustman EM, Mendrick DL, Fowle JR, Hartung T, Tice RR, Lemazurier E, Becker RA, Fitzpatrick SC, Daston GP, Harrill A, Hines RN, Keller DA, Lipscomb JC, Watson D, Bahadori T, Crofton KM. FutureTox III: Bridges for Translation. Toxicol Sci 2016; 155:22-31. [PMID: 27780885 DOI: 10.1093/toxsci/kfw194] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Future Tox III, a Society of Toxicology Contemporary Concepts in Toxicology workshop, was held in November 2015. Building upon Future Tox I and II, Future Tox III was focused on developing the high throughput risk assessment paradigm and taking the science of in vitro data and in silico models forward to explore the question-what progress is being made to address challenges in implementing the emerging big-data toolbox for risk assessment and regulatory decision-making. This article reports on the outcome of the workshop including 2 examples of where advancements in predictive toxicology approaches are being applied within Federal agencies, where opportunities remain within the exposome and AOP domains, and how collectively the toxicology community across multiple sectors can continue to bridge the translation from historical approaches to Tox21 implementation relative to risk assessment and regulatory decision-making.
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Affiliation(s)
| | - Thomas B Knudsen
- US Environmental Protection Agency, Research Triangle Park, North Carolina
| | | | - Nancy B Beck
- American Chemistry Council, Washington, The District of Columbia
| | | | | | - John R Fowle
- Science to Inform, LLC, Pittsboro, North Carolina
| | - Thomas Hartung
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Raymond R Tice
- National Toxicology Program/National Institute of Environmental Health Sciences, Durham, North Carolina
| | | | - Richard A Becker
- American Chemistry Council, Washington, The District of Columbia
| | | | | | - Alison Harrill
- University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Ronald N Hines
- US Environmental Protection Agency, Research Triangle Park, North Carolina
| | | | | | | | - Tina Bahadori
- US Environmental Protection Agency, Washington, The District of Columbia
| | - Kevin M Crofton
- US Environmental Protection Agency, Research Triangle Park, North Carolina
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De Abrew KN, Kainkaryam RM, Shan YK, Overmann GJ, Settivari RS, Wang X, Xu J, Adams RL, Tiesman JP, Carney EW, Naciff JM, Daston GP. Grouping 34 Chemicals Based on Mode of Action Using Connectivity Mapping. Toxicol Sci 2016; 151:447-61. [DOI: 10.1093/toxsci/kfw058] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Naciff JM, Khambatta ZS, Carr GJ, Tiesman JP, Singleton DW, Khan SA, Daston GP. Dose- and Time-Dependent Transcriptional Response of Ishikawa Cells Exposed to Genistein. Toxicol Sci 2016; 151:71-87. [PMID: 26865667 DOI: 10.1093/toxsci/kfw024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
To further define the utility of the Ishikawa cells as a reliable in vitro model to determine the potential estrogenic activity of chemicals of interest, transcriptional changes induced by genistein (GES) in Ishikawa cells at various doses (10 pM, 1 nM, 100 nM, and 10 μM) and time points (8, 24, and 48 h) were identified using a comprehensive microarray approach. Trend analysis indicated that the expression of 5342 unique genes was modified by GES in a dose- and time-dependent manner (P ≤ 0.0001). However, the majority of gene expression changes induced in Ishikawa cells were elicited by the highest dose of GES evaluated (10 μM). The GES' estrogenic activity was identified by comparing the Ishikawa cells' response to GES versus 17 α-ethynyl estradiol (EE, at equipotent doses, ie, 10 μM vs 1 μM, respectively) and was defined by changes in the expression of 284 unique genes elicited by GES and EE in the same direction, although the magnitude of the change for some genes was different. Further, comparing the response of the Ishikawa cells exposed to high doses of GES and EE versus the response of the juvenile rat uterus exposed to EE, we identified 66 unique genes which were up- or down regulated in a similar manner in vivo as well as in vitro Genistein elicits changes in multiple molecular pathways affecting various biological processes particularly associated with cell organization and biogenesis, regulation of translation, cell proliferation, and intracellular transport; processes also affected by estrogen exposure in the uterus of the rat. These results indicate that Ishikawa cells are capable of generating a biologically relevant estrogenic response and offer an in vitro model to assess this mode of action.
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Affiliation(s)
- Jorge M Naciff
- *Mason Business Center, The Procter and Gamble Company, Mason, Ohio 45040
| | - Zubin S Khambatta
- *Mason Business Center, The Procter and Gamble Company, Mason, Ohio 45040
| | - Gregory J Carr
- *Mason Business Center, The Procter and Gamble Company, Mason, Ohio 45040
| | - Jay P Tiesman
- *Mason Business Center, The Procter and Gamble Company, Mason, Ohio 45040
| | - David W Singleton
- Department of Cell Biology, Neurobiology, and Anatomy, Vontz Center for Molecular Studies, University of Cincinnati, Cincinnati, Ohio 45267
| | - Sohaib A Khan
- Department of Cell Biology, Neurobiology, and Anatomy, Vontz Center for Molecular Studies, University of Cincinnati, Cincinnati, Ohio 45267
| | - George P Daston
- *Mason Business Center, The Procter and Gamble Company, Mason, Ohio 45040
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Daston GP, Rogers JM. Obituary. Edward W. Carney, 1959-2015. ACTA ACUST UNITED AC 2015; 104:53-4. [PMID: 26097067 DOI: 10.1002/bdrb.21141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Felter SP, Daston GP, Euling SY, Piersma AH, Tassinari MS. Assessment of health risks resulting from early-life exposures: Are current chemical toxicity testing protocols and risk assessment methods adequate? Crit Rev Toxicol 2015; 45:219-44. [PMID: 25687245 DOI: 10.3109/10408444.2014.993919] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract Over the last couple of decades, the awareness of the potential health impacts associated with early-life exposures has increased. Global regulatory approaches to chemical risk assessment are intended to be protective for the diverse human population including all life stages. However, questions persist as to whether the current testing approaches and risk assessment methodologies are adequately protective for infants and children. Here, we review physiological and developmental differences that may result in differential sensitivity associated with early-life exposures. It is clear that sensitivity to chemical exposures during early-life can be similar, higher, or lower than that of adults, and can change quickly within a short developmental timeframe. Moreover, age-related exposure differences provide an important consideration for overall susceptibility. Differential sensitivity associated with a life stage can reflect the toxicokinetic handling of a xenobiotic exposure, the toxicodynamic response, or both. Each of these is illustrated with chemical-specific examples. The adequacy of current testing protocols, proposed new tools, and risk assessment methods for systemic noncancer endpoints are reviewed in light of the potential for differential risk to infants and young children.
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Daston GP, Beyer BK, Carney EW, Chapin RE, Friedman JM, Piersma AH, Rogers JM, Scialli AR. Exposure‐Based Validation List for Developmental Toxicity Screening Assays. ACTA ACUST UNITED AC 2014; 101:423-8. [DOI: 10.1002/bdrb.21132] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/15/2014] [Indexed: 11/08/2022]
Affiliation(s)
| | - Bruce K. Beyer
- Department of Disposition Safety and Animal Research–Preclinical Safety Sanofi U.S. Inc Bridgewater New Jersey
| | | | | | - Jan M. Friedman
- Department of Medical Genetics Child & Family Research Institute University of British Columbia Vancouver British Columbia Canada
| | - Aldert H. Piersma
- RIVM Bilthoven Utrecht The Netherlands
- Institute for Risk Assessment Sciences (IRAS) Utrecht University Utrecht The Netherlands
| | - John M. Rogers
- Toxicity Assessment Division NHEERL ORD, U.S. Environmental Protection Agency Research Triangle Park North Carolina
| | - Anthony R. Scialli
- The Reproductive Toxicology Center Washington District of Columbia
- School of Medicine, George Washington University Washington District of Columbia
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Horstman KA, Naciff JM, Overmann GJ, Foertsch LM, Richardson BD, Daston GP. Effects of transplacental 17-α-ethynyl estradiol or bisphenol A on the developmental profile of steroidogenic acute regulatory protein in the rat testis. ACTA ACUST UNITED AC 2012; 95:318-25. [PMID: 22752971 DOI: 10.1002/bdrb.21020] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 06/06/2012] [Indexed: 11/08/2022]
Abstract
Previous research from our laboratory has determined the transcript profiles for developing fetal rat female and male reproductive tracts following transplacental exposure to estrogens. Prenatal exposure to bisphenol A (BPA) or 17-α-ethynyl estradiol (EE) significantly affects steroidogenic acute regulatory (StAR) protein transcript levels in the developing male rat reproductive tract. The purpose of this study was to establish the intratesticular distribution and temporal expression pattern of StAR, a key gene involved in steroidogenesis. Beginning on gestation day (GD) 11, pregnant Sprague-Dawley rats were exposed daily to 10μg/kg/day EE and fetal testes were harvested at GD16, 18, or 20. Quantitative reverse transcriptase PCR (QRT-PCR) demonstrated no significant difference in StAR transcript levels present at GD16. However, at GD18, StAR transcripts were significantly decreased following exposure. Immunohistochemistry demonstrated similar StAR protein levels in interstitial region of GD16 testes and an obvious decrease in StAR protein levels in the interstitial region of GD18 testes. Moreover, starting at GD11 additional dams were dosed with 0.001 or 0.1 μg/kg/day EE or 0.02, 0.5, 400 mg/kg/day BPA via subcutaneous injections. QRT-PCR validated previous microarray dose-related decreases in StAR transcripts at GD20, whereas immunohistochemistry results demonstrated decreases in StAR protein levels in the interstitial region at the highest EE and BPA doses only. Neither EE nor BPA exposure caused morphological changes in the developing seminiferous cords, Sertoli cells, gonocytes, or the interstitial region or Leydig cells at GD16-20. High levels of estrogens decrease StAR expression in the fetal rat testis during late gestation.
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Affiliation(s)
- Karla A Horstman
- Mason Business Center, The Procter and Gamble Company, Mason, OH, USA
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Knudsen TB, Kavlock RJ, Daston GP, Stedman D, Hixon M, Kim JH. Developmental toxicity testing for safety assessment: new approaches and technologies. ACTA ACUST UNITED AC 2011; 92:413-20. [PMID: 21770025 DOI: 10.1002/bdrb.20315] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 05/31/2011] [Indexed: 11/11/2022]
Abstract
The ILSI Health and Environmental Sciences Institute's Developmental and Reproductive Toxicology Technical Committee held a 2-day workshop entitled "Developmental Toxicology-New Directions" in April 2009. The fourth session of this workshop focused on new approaches and technologies for the assessment of developmental toxicology. This session provided an overview of the application of genomics technologies for developmental safety assessment, the use of mouse embryonic stem cells to capture data on developmental toxicity pathways, dynamical cell imaging of zebrafish embryos, the use of computation models of development pathways and systems, and finally, high-throughput in vitro approaches being utilized by the EPA ToxCast program. Issues discussed include the challenges of anchoring in vitro predictions to relevant in vivo endpoints and the need to validate pathway-based predictions with targeted studies in whole animals. Currently, there are 10,000 to 30,000 chemicals in world-wide commerce in need of hazard data for assessing potential health risks. The traditional animal study designs for assessing developmental toxicity cannot accommodate the evaluation of this large number of chemicals, requiring that alternative technologies be utilized. Though a daunting task, technologies are being developed and utilized to make that goal reachable.
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Affiliation(s)
- Thomas B Knudsen
- National Center for Computational Toxicology, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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Abstract
Laboratory models have an important role in identifying exposures with teratogenic potential, determining mechanisms of abnormal development, and supporting or refuting the biological plausibility of associations identified in human studies. Laboratory animals are the most widely used models, but are rapidly being supplemented by in vitro tools. Testing paradigms that have been in place since the mid-1960s for pharmaceuticals, and soon thereafter for industrial chemicals and pesticides, have been used to evaluate the potential developmental toxicity of thousands of agents. These models have served as the principal basis for regulatory decisions about acceptable exposure levels and restrictions on use of certain drugs during pregnancy.
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Affiliation(s)
- George P Daston
- Miami Valley Innovation Center, The Procter & Gamble Company, Cincinnati, OH 45253, USA.
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Daston GP, Chapin RE, Scialli AR, Piersma AH, Carney EW, Rogers JM, Friedman JM. A different approach to validating screening assays for developmental toxicity. ACTA ACUST UNITED AC 2010; 89:526-30. [DOI: 10.1002/bdrb.20276] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Daston GP. Alternative testing: Validation, selection of chemicals and testing strategies. Reprod Toxicol 2010. [DOI: 10.1016/j.reprotox.2010.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Rusyn I, Daston GP. Computational toxicology: realizing the promise of the toxicity testing in the 21st century. Environ Health Perspect 2010; 118:1047-50. [PMID: 20483702 PMCID: PMC2920091 DOI: 10.1289/ehp.1001925] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 05/18/2010] [Indexed: 05/20/2023]
Abstract
BACKGROUND The National Academies' Standing Committee on Use of Emerging Science for Environmental Health Decisions held a meeting (21-22 September 2009 in Washington, DC) titled "Computational Toxicology: From Data to Analyses to Applications." This commentary reflects on the presentations and roundtable discussions from the meeting that were designed to review the state of the art in the field and the practical applications of the new science and to provide focus to the field. OBJECTIVES The meeting considered two topics: the emerging data streams amenable to computational modeling and data mining, and the emerging data analysis and modeling tools. DISCUSSION Computational toxicology is a subdiscipline of toxicology that aims to use the mathematical, statistical, modeling, and computer science tools to better understand the mechanisms through which a given chemical induces harm and, ultimately, to be able to predict adverse effects of the toxicants on human health and/or the environment. The participants stressed the importance of computational toxicology to the future of environmental health sciences and regulatory decisions in public health; however, many challenges remain to be addressed before the findings from high-throughput screens and in silico models may be considered sufficiently robust and informative. CONCLUSIONS Many scientists, regulators, and the general public believe that new and better ways to assess human toxicity are now needed, and technological breakthroughs are empowering the field of toxicity assessment. Even though the application of computational toxicology to environmental health decisions requires additional efforts, the merger of the power of computers with biological information is poised to deliver new tools and knowledge.
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Affiliation(s)
- Ivan Rusyn
- Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina 27599-7431, USA.
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Daston GP. Introduction to special issue on developmental and reproductive toxicology in China. ACTA ACUST UNITED AC 2010; 89:1. [PMID: 20166228 DOI: 10.1002/bdrb.20239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Naciff JM, Khambatta ZS, Reichling TD, Carr GJ, Tiesman JP, Singleton DW, Khan SA, Daston GP. The genomic response of Ishikawa cells to bisphenol A exposure is dose- and time-dependent. Toxicology 2010; 270:137-49. [DOI: 10.1016/j.tox.2010.02.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 02/08/2010] [Accepted: 02/09/2010] [Indexed: 10/19/2022]
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Naciff JM, Khambatta ZS, Thomason RG, Carr GJ, Tiesman JP, Singleton DW, Khan SA, Daston GP. The genomic response of a human uterine endometrial adenocarcinoma cell line to 17alpha-ethynyl estradiol. Toxicol Sci 2008; 107:40-55. [PMID: 18936297 DOI: 10.1093/toxsci/kfn219] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have determined the gene expression profile induced by 17 alpha-ethynyl estradiol (EE) in Ishikawa cells, a human uterine-derived estrogen-sensitive cell line, at various doses (1 pM, 100 pM, 10 nM, and 1 microM) and time points (8, 24, and 48 h). The transcript profiles were compared between treatment groups and controls (vehicle-treated) using high-density oligonucleotide arrays to determine the expression level of approximately 38,500 human genes. By trend analysis, we determined that the expression of 2560 genes was modified by exposure to EE in a dose- and time-dependent manner (p </= 0.0001). The annotation available for the genes affected indicates that EE exposure results in changes in multiple molecular pathways affecting various biological processes, particularly associated with development, morphogenesis, organogenesis, cell proliferation, cell organization, and biogenesis. All of these processes are also affected by estrogen exposure in the uterus of the rat. Comparison of the response to EE in both the rat uterus and the Ishikawa cells showed that 71 genes are regulated in a similar manner in vivo as well as in vitro. Further, some of the genes that show a robust response to estrogen exposure in Ishikawa cells are well known to be estrogen responsive, in various in vivo studies, such as PGR, MMP7, IGFBP3, IGFBP5, SOX4, MYC, EGR1, FOS, CKB, and CCND2, among others. These results indicate that transcript profiling can serve as a viable tool to select reliable in vitro systems to evaluate potential estrogenic activities of target chemicals and to identify genes that are relevant for the estrogen response.
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Affiliation(s)
- Jorge M Naciff
- Miami Valley Innovation Center, The Procter and Gamble Company, Cincinnati, Ohio 45253, USA
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Dobson RLM, Motlagh S, Quijano M, Cambron RT, Baker TR, Pullen AM, Regg BT, Bigalow-Kern AS, Vennard T, Fix A, Reimschuessel R, Overmann G, Shan Y, Daston GP. Identification and Characterization of Toxicity of Contaminants in Pet Food Leading to an Outbreak of Renal Toxicity in Cats and Dogs. Toxicol Sci 2008; 106:251-62. [PMID: 18689873 DOI: 10.1093/toxsci/kfn160] [Citation(s) in RCA: 357] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Roy L M Dobson
- The Procter & Gamble Company, Cincinnati, Ohio 45253, USA
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Affiliation(s)
- George P Daston
- Central Product Safety, Procter & Gamble, Cincinnati, Ohio 45253, USA.
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Hoberman AM, Schreur DK, Leazer T, Daston GP, Carthew P, Re T, Loretz L, Mann P. Lack of effect of butylparaben and methylparaben on the reproductive system in male rats. ACTA ACUST UNITED AC 2008; 83:123-33. [PMID: 18393383 DOI: 10.1002/bdrb.20153] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Parabens are widely used preservatives in cosmetics and pharmaceutical products, and approved as food additives. Parabens have been considered safe for these uses for many years. Recently, adverse effects on male reproductive parameters in rats have been reported when parabens were given orally for 8 weeks starting at three weeks of age. Our studies used two representative parabens, methyl- and butylparaben, to try to replicate these studies and thereby evaluate potential reproductive effects in male Wistar rats. METHODS Diets containing 0, 100, 1000 or 10,000 ppm of either butyl- or methylparaben were fed to male rats for eight weeks. Rats were 22 days of age at the start of exposure. Parameters evaluated included organ weights, histopathology of reproductive tissues, sperm production, motility, morphology and reproductive hormone levels (butylparaben only). RESULTS None of the parameters evaluated for either paraben showed compound- or dosage-dependent adverse effects. Metabolism experiments of butylparaben indicate that it is rapidly metabolized by non-specific esterases to p-hydroxybenzoic acid and butanol, neither of which is estrogenic. CONCLUSIONS Exposure to methyl- or butylparaben in the diet for eight weeks did not affect any male reproductive organs or parameters at exposures as high as 10,000 ppm, corresponding to a mean daily dose of 1,141.1+/-58.9 or 1,087.6+/-67.8 mg/kg/day for methyl- and butylparaben, respectively. The rapid metabolism of parabens by esterases probably explains why these weakly estrogenic substances elicit no in vivo effects when administered by relevant exposure routes (i.e., topical and oral).
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Daston GP. CERHR bisphenol A: review and commentaries. Birth Defects Res B Dev Reprod Toxicol 2008; 83:151. [PMID: 18570259 DOI: 10.1002/bdrb.20159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Daston GP, Rogers JM. Casimer T. Grabowski: 1927-2007. Birth Defects Res B Dev Reprod Toxicol 2008; 83:149-150. [PMID: 18383314 DOI: 10.1002/bdrb.20151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Daston GP, Seed J. Skeletal malformations and variations in developmental toxicity studies: interpretation issues for human risk assessment. ACTA ACUST UNITED AC 2008; 80:421-4. [PMID: 18157902 DOI: 10.1002/bdrb.20135] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- George P Daston
- Miami Valley Innovation Center, Procter & Gamble, Cincinnati, Ohio 45253, USA.
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Balbus JM, Maynard AD, Colvin VL, Castranova V, Daston GP, Denison RA, Dreher KL, Goering PL, Goldberg AM, Kulinowski KM, Monteiro-Riviere NA, Oberdörster G, Omenn GS, Pinkerton KE, Ramos KS, Rest KM, Sass JB, Silbergeld EK, Wong BA. Meeting report: hazard assessment for nanoparticles--report from an interdisciplinary workshop. Environ Health Perspect 2007; 115:1654-9. [PMID: 18007999 PMCID: PMC2072837 DOI: 10.1289/ehp.10327] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 08/14/2007] [Indexed: 05/17/2023]
Abstract
In this report we present the findings from a nanotoxicology workshop held 6-7 April 2006 at the Woodrow Wilson International Center for Scholars in Washington, DC. Over 2 days, 26 scientists from government, academia, industry, and nonprofit organizations addressed two specific questions: what information is needed to understand the human health impact of engineered nanoparticles and how is this information best obtained? To assess hazards of nanoparticles in the near-term, most participants noted the need to use existing in vivo toxicologic tests because of their greater familiarity and interpretability. For all types of toxicology tests, the best measures of nanoparticle dose need to be determined. Most participants agreed that a standard set of nanoparticles should be validated by laboratories worldwide and made available for benchmarking tests of other newly created nanoparticles. The group concluded that a battery of tests should be developed to uncover particularly hazardous properties. Given the large number of diverse materials, most participants favored a tiered approach. Over the long term, research aimed at developing a mechanistic understanding of the numerous characteristics that influence nanoparticle toxicity was deemed essential. Predicting the potential toxicity of emerging nanoparticles will require hypothesis-driven research that elucidates how physicochemical parameters influence toxic effects on biological systems. Research needs should be determined in the context of the current availability of testing methods for nanoscale particles. Finally, the group identified general policy and strategic opportunities to accelerate the development and implementation of testing protocols and ensure that the information generated is translated effectively for all stakeholders.
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Naciff JM, Overmann GJ, Torontali SM, Carr GJ, Khambatta ZS, Tiesman JP, Richardson BD, Daston GP. Uterine Temporal Response to Acute Exposure to 17α-Ethinyl Estradiol in the Immature Rat. Toxicol Sci 2007; 97:467-90. [PMID: 17351261 DOI: 10.1093/toxsci/kfm046] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The rat uterus responds to acute estrogen treatment with a series of well-characterized physiological responses; however, the gene expression changes required to elicit these responses have not been fully characterized. In order to understand early events induced by estrogen exposure in vivo, we evaluated the temporal gene expression in the uterus of the immature rat after a single dose of 17 alpha-ethinyl estradiol (EE) by microarray analysis, evaluating the expression of 15,923 genes. Immature 20-day-old rats were exposed to a single dose of EE (10 microg/kg), and the effects on uterine histology, weight, and gene expression were determined after 1, 2, 8, 24, 48, 72, and 96 h. EE induced changes in the expression of 3867 genes, at least at one time point (p < or = 0.0001), and at least 1.5-fold (up- or downregulated). Specifically, the expression of 8, 116, 3030, 2076, 381, 445, and 125 genes was modified at 1, 2, 8, 24, 48, 72, or 96 h after exposure to EE, respectively (p < or = 0.0001, t-test). At the tissue and organ level, a clear uterotrophic response was elicited by EE after only 8 h, reaching a maximum after 24 h and remaining detectable even after 96 h of exposure. The uterine phenotypic changes were induced by sequential changes in the transcriptional status of a large number of genes, in a program that involves multiple molecular pathways. Using the Gene Ontology to better understand the temporal response to estrogen exposure, we determined that the earliest changes were in the expression of genes whose products are involved in transcriptional regulation and signal transduction, followed by genes implicated in protein synthesis, energy utilization, solute transport, cell proliferation and differentiation, tissue remodeling, and immunological responses among other pathways. The compendium of genes here presented represents a comprehensive compilation of estrogen-responsive genes involved in the uterotrophic response.
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Affiliation(s)
- Jorge M Naciff
- The Procter and Gamble Company, Miami Valley Innovation Center, Cincinnati, OH 45253, USA.
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Affiliation(s)
- George P Daston
- Miami Valley Innovation Center, Procter & Gamble, PO Box 538707, Cincinnati, Ohio 45253, USA.
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Rogers JM, Daston GP, Uriu-Adams J, Hanna LA, Keen CL. Dose-Dependent Transitions in Mechanisms of Toxicity: Zinc Case Example. Toxicol Lett 2006. [DOI: 10.1016/j.toxlet.2006.06.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Harding AK, Daston GP, Boyd GR, Lucier GW, Safe SH, Stewart J, Tillitt DE, Van Der Kraak G. Endocrine disrupting chemicals research program of the U.S. Environmental Protection Agency: summary of a peer-review report. Environ Health Perspect 2006; 114:1276-82. [PMID: 16882539 PMCID: PMC1552001 DOI: 10.1289/ehp.8875] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
At the request of the U.S. Environmental Protection Agency (EPA) Office of Research and Development, a subcommittee of the Board of Scientific Counselors Executive Committee conducted an independent and open peer review of the Endocrine Disrupting Chemicals Research Program (EDC Research Program) of the U.S. EPA. The subcommittee was charged with reviewing the design, relevance, progress, scientific leadership, and resources of the program. The subcommittee found that the long-term goals and science questions in the EDC Program are appropriate and represent an understandable and solid framework for setting research priorities, representing a combination of problem-driven and core research. Long-term goal (LTG) 1, dealing with the underlying science surrounding endocrine disruptors, provides a solid scientific foundation for conducting risk assessments and making risk management decisions. LTG 2, dealing with defining the extent of the impact of endocrine-disrupting chemicals (EDCs), has shown greater progress on ecologic effects of EDCs compared with that on human health effects. LTG 3, which involves support of the Endocrine Disruptor Screening and Testing Program of the U.S. EPA, has two mammalian tests already through a validation program and soon available for use. Despite good progress, we recommend that the U.S. EPA a) strengthen their expertise in wildlife toxicology, b) expedite validation of the Endocrine Disruptors Screening and Testing Advisory Committee tests, c) continue dependable funding for the EDC Research Program, d) take a leadership role in the application of "omics" technologies to address many of the science questions critical for evaluating environmental and human health effects of EDCs, and e) continue to sponsor multidisciplinary intramural research and interagency collaborations.
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Affiliation(s)
- Anna K Harding
- Department of Public Health, Oregon State University, Corvallis, Oregon 97331-6406, USA.
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Ankley GT, Daston GP, Degitz SJ, Denslow ND, Hoke RA, Kennedy SW, Miracle AL, Perkins EJ, Snape J, Tillitt DE, Tyler CR, Versteeg D. Toxicogenomics in regulatory ecotoxicology. Environ Sci Technol 2006; 40:4055-65. [PMID: 16856717 PMCID: PMC1892581 DOI: 10.1021/es0630184] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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Felter SP, Vassallo JD, Carlton BD, Daston GP. A safety assessment of coumarin taking into account species-specificity of toxicokinetics. Food Chem Toxicol 2006; 44:462-75. [PMID: 16203076 DOI: 10.1016/j.fct.2005.08.019] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 08/19/2005] [Accepted: 08/22/2005] [Indexed: 11/16/2022]
Abstract
Coumarin (1,2-benzopyrone) is a naturally occurring fragrant compound found in a variety of plants and spices. Exposure to the general public is through the diet and from its use as a perfume raw material in personal care products. High doses of coumarin by the oral route are known to be associated with liver toxicity in rodents. Chronic oral bioassays conducted in the 1990s reported liver tumors in rats and mice and lung tumors in mice, raising concerns regarding the safety of coumarin. Since then, an extensive body of research has focused on understanding the etiology of these tumors. The data support a conclusion that coumarin is not DNA-reactive and that the induction of tumors at high doses in rodents is attributed to cytotoxicity and regenerative hyperplasia. The species-specific target organ toxicity is shown to be related to the pharmacokinetics of coumarin metabolism, with data showing rats to be particularly susceptible to liver effects and mice to be particularly susceptible to lung effects. A quantitative human health risk assessment that integrates both cancer and non-cancer effects is presented, confirming the safety of coumarin exposure from natural dietary sources as well as from its use as a perfume in personal care products.
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Affiliation(s)
- S P Felter
- The Procter & Gamble Company, Miami Valley Innovation Center, 11810 E. Miami River Road, Cincinnati, OH 45252, USA.
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Lawson CC, Grajewski B, Daston GP, Frazier LM, Lynch D, McDiarmid M, Murono E, Perreault SD, Robbins WA, Ryan MAK, Shelby M, Whelan EA. Workgroup report: Implementing a national occupational reproductive research agenda--decade one and beyond. Environ Health Perspect 2006; 114:435-41. [PMID: 16507468 PMCID: PMC1392239 DOI: 10.1289/ehp.8458] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Accepted: 10/26/2005] [Indexed: 05/06/2023]
Abstract
The initial goal of occupational reproductive health research is to effectively study the many toxicants, physical agents, and biomechanical and psychosocial stressors that may constitute reproductive hazards in the workplace. Although the main objective of occupational reproductive researchers and clinicians is to prevent recognized adverse reproductive outcomes, research has expanded to include a broader spectrum of chronic health outcomes potentially affected by reproductive toxicants. To aid in achieving these goals, the National Institute for Occupational Safety and Health, along with its university, federal, industry, and labor colleagues, formed the National Occupational Research Agenda (NORA) in 1996. NORA resulted in 21 research teams, including the Reproductive Health Research Team (RHRT). In this report, we describe progress made in the last decade by the RHRT and by others in this field, including prioritizing reproductive toxicants for further study; facilitating collaboration among epidemiologists, biologists, and toxicologists; promoting quality exposure assessment in field studies and surveillance; and encouraging the design and conduct of priority occupational reproductive studies. We also describe new tools for screening reproductive toxicants and for analyzing mode of action. We recommend considering outcomes such as menopause and latent adverse effects for further study, as well as including exposures such as shift work and nanomaterials. We describe a broad domain of scholarship activities where a cohesive system of organized and aligned work activities integrates 10 years of team efforts and provides guidance for future research.
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Affiliation(s)
- Christina C Lawson
- National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226-1998, USA.
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Luderer U, Collins TFX, Daston GP, Fischer LJ, Gray RH, Mirer FE, Olshan AF, Setzer RW, Treinen KA, Vermeulen R. NTP-CERHR Expert Panel Report on the reproductive and developmental toxicity of styrene. ACTA ACUST UNITED AC 2006; 77:110-93. [PMID: 16345075 DOI: 10.1002/bdrb.20061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Henderson RF, Stewart J, Daston GP, Duke CS, Farland W. EPA risk assessment principles and practices. BOSC (board of scientific counselors) workshop, February 2-3, 2005, Washington, DC. Environ Sci Pollut Res Int 2005; 12:388-90. [PMID: 16305146 DOI: 10.1065/espr2005.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
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Rogers JM, Chernoff N, Keen CL, Daston GP. Evaluation and interpretation of maternal toxicity in Segment II studies: Issues, some answers, and data needs. Toxicol Appl Pharmacol 2005; 207:367-74. [PMID: 15982694 DOI: 10.1016/j.taap.2005.03.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Revised: 02/21/2005] [Accepted: 03/31/2005] [Indexed: 11/25/2022]
Abstract
Biologically rational regulatory policies with regards to developmental toxicity are often based on the extrapolation of standard laboratory rodent bioassay results to the human population. Significantly contributing to the difficulty of this task is the possibility that general toxic effects on the maternal organism may affect the developing conceptus. This review examines maternal factors which may bear directly or indirectly upon developmental outcome, with emphasis on those of greatest relevance to the hazard assessment process. Standard teratology testing protocols call for top dosage levels that induce overt maternal toxicity, and the developmental effects of this toxicity (both alone, and with concurrent embryo/fetal insult) continue to present regulators with considerable interpretive difficulties. In response to these problems, there have been both research and literature review efforts dealing with the relationship of maternal and developmental toxicity. Maternally mediated developmental toxicity occurs with a number of agents, and toxicant-induced alterations in maternal physiology may affect the conceptus at dosages not causing overt maternal toxicity. Relevant studies are reviewed here, and suggestions for avenues of future research are offered including the identification of any syndromes of developmental effects occurring at maternally toxic levels irrespective of the causative agent, and experimental approaches for the characterization of maternal toxicity.
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Affiliation(s)
- John M Rogers
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, MD-67, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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Naciff JM, Richardson BD, Oliver KG, Jump ML, Torontali SM, Juhlin KD, Carr GJ, Paine JR, Tiesman JP, Daston GP. Design of a microsphere-based high-throughput gene expression assay to determine estrogenic potential. Environ Health Perspect 2005; 113:1164-71. [PMID: 16140622 PMCID: PMC1280396 DOI: 10.1289/ehp.7843] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Recently gene expression studies have been multiplied at an accelerated rate by the use of high-density microarrays. By assaying thousands of transcripts at a time, microarrays have led to the discovery of dozens of genes involved in particular biochemical processes, for example, the response of a tissue/organ to a given chemical with therapeutic or toxic properties. The next step in these studies is to focus on the response of a subset of relevant genes to verify or refine potential therapeutic or toxic properties. We have developed a sensitive, high-throughput gene expression assay for this purpose. In this assay, based on the Luminex xMAP system, carefully selected oligonucleotides were covalently linked to fluorescently coded microspheres that are hybridized to biotinylated cRNA followed by amplification of the signal, which results in a rapid, sensitive, multiplexed assay platform. Using this system, we have developed an RNA expression profiling assay specific for 17 estrogen-responsive transcripts and three controls. This assay can evaluate up to 100 distinct analytes simultaneously in a single sample, in a 96-well plate format. This system has improved sensitivity versus existing microsphere-based assays and has sensitivity and precision comparable with or better than microarray technology. We have achieved detection levels down to 1 amol, detecting rare messages in complex cRNA samples, using as little as 2.5 microg starting cRNA. This assay offers increased throughput with decreased costs compared with existing microarray technologies, with the trade-off being in the total number of transcripts that can be analyzed.
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Affiliation(s)
- Jorge M Naciff
- Miami Valley Innovation Center, Procter & Gamble Company, Cincinnati, OH 45253, USA.
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