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Eytcheson SA, Zosel AD, Olker JH, Hornung MW, Degitz SJ. In Vitro Screening for ToxCast Chemicals Binding to Thyroxine-Binding Globulin. Chem Res Toxicol 2024. [PMID: 39268642 DOI: 10.1021/acs.chemrestox.4c00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2024]
Abstract
Thyroid hormone (TH) carrier proteins play an important role in distributing TH to target tissue as well as maintaining the balance of free versus bound TH in the blood. Interference with the TH carrier proteins has been identified as a potential mechanism of thyroid system disruption. To address the lack of data regarding chemicals binding to these carrier proteins and displacing TH, a fluorescence-based in vitro screening assay was utilized to screen over 1,400 chemicals from the U.S. EPA's ToxCast phase1_v2, phase 2, and e1k libraries for competitive binding to one of the carrier proteins, thyroxine-binding globulin. Initial screening at a single high concentration of 100 μM identified 714 chemicals that decreased signal of the bound fluorescent ligand by 20% or higher. Of these, 297 produced 50% or greater reduction in fluorescence and were further tested in concentration-response (0.004 to 150 μM) to determine relative potency. Ten chemicals were found to have EC50 values <1 μM, 63 < 10 μM, and 141 chemicals between 10 and 100 μM. Utilization of this assay contributes to expanding the number of in vitro assays available for identifying chemicals with the potential to disrupt TH homeostasis. These results support ranking and prioritization of chemicals to be tested in vivo to aid in the development of a framework for predicting in vivo effects from in vitro high-throughput data.
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Affiliation(s)
- Stephanie A Eytcheson
- Oak Ridge Institute for Science and Education Postdoctoral Fellow, Oak Ridge, Tennessee 37830, United States
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
| | - Alexander D Zosel
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
- Oak Ridge Associated Universities Student Services Contractor, Oak Ridge, Tennessee 37830, United States
| | - Jennifer H Olker
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
| | - Michael W Hornung
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
| | - Sigmund J Degitz
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
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Eytcheson SA, Zosel AD, Olker JH, Hornung MW, Degitz SJ. Screening the ToxCast Chemical Libraries for Binding to Transthyretin. Chem Res Toxicol 2024. [PMID: 39258767 DOI: 10.1021/acs.chemrestox.4c00215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Transthyretin (TTR) is one of the serum binding proteins responsible for transport of thyroid hormones (TH) to target tissue and for maintaining the balance of available TH. Chemical binding to TTR and subsequent displacement of TH has been identified as an end point in screening chemicals for potential disruption of the thyroid system. To address the lack of data regarding chemicals binding to TTR, we optimized an in vitro assay utilizing the fluorescent probe 8-anilino-1-napthalenesulfonic acid (ANSA) and the human protein TTR to screen over 1500 chemicals from the U.S. EPA's ToxCast ph1_v2, ph2, and e1k libraries utilizing a tiered approach. Testing of a single high concentration (target 100 μM) resulted in 888 chemicals with 20% or greater activity based on displacement of ANSA from TTR. Of these, 282 chemicals had activity of 85% or greater and were further tested in 12-point concentration-response with target concentrations ranging from 0.015 to 100 μM. An EC50 was obtained for 276 of these 301 chemicals. To date, this is the largest set of chemicals screened for binding to TTR. Utilization of this assay is a significant contribution toward expanding the suite of in vitro assays used to identify chemicals with the potential to disrupt thyroid hormone homeostasis.
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Affiliation(s)
- Stephanie A Eytcheson
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830, United States
- Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Duluth, Minnesota 55804, United States
| | - Alexander D Zosel
- Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Duluth, Minnesota 55804, United States
- Oak Ridge Associated Universities Student Services Contractor, Oak Ridge, Tennessee 37830, United States
| | - Jennifer H Olker
- Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Duluth, Minnesota 55804, United States
| | - Michael W Hornung
- Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Duluth, Minnesota 55804, United States
| | - Sigmund J Degitz
- Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Duluth, Minnesota 55804, United States
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Lai Y, Ay M, Hospital CD, Miller GW, Sarkar S. Seminar: Functional Exposomics and Mechanisms of Toxicity-Insights from Model Systems and NAMs. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:94201. [PMID: 39230330 PMCID: PMC11373422 DOI: 10.1289/ehp13120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
BACKGROUND Significant progress has been made over the past decade in measuring the chemical components of the exposome, providing transformative population-scale frameworks in probing the etiologic link between environmental factors and disease phenotypes. While the analytical technologies continue to evolve with reams of data being generated, there is an opportunity to complement exposome-wide association studies (ExWAS) with functional analyses to advance etiologic search at organismal, cellular, and molecular levels. OBJECTIVES Exposomics is a transdisciplinary field aimed at enabling discovery-based analysis of the nongenetic factors that contribute to disease, including numerous environmental chemical stressors. While advances in exposure assessment are enhancing population-based discovery of exposome-wide effects and chemical exposure agents, functional screening and elucidation of biological effects of exposures represent the next logical step toward precision environmental health and medicine. In this work, we focus on the use, strategies, and prospects of alternative approaches and model systems to enhance the current human exposomics framework in biomarker search and causal understanding, spanning from bench-based nonmammalian organisms and cell culture to computational new approach methods (NAMs). DISCUSSION We visit the definition of the functional exposome and exposomics and discuss a need to leverage alternative models as opposed to mammalian animals for delineating exposome-wide health effects. Under the "three Rs" principle of reduction, replacement, and refinement, model systems such as roundworms, fruit flies, zebrafish, and induced pluripotent stem cells (iPSCs) are advantageous over mammals (e.g., rodents or higher vertebrates). These models are cost-effective, and cell-specific genetic manipulations in these models are easier and faster, compared to mammalian models. Meanwhile, in silico NAMs enhance hazard identification and risk assessment in humans by bridging the translational gaps between toxicology data and etiologic inference, as represented by in vitro to in vivo extrapolation (IVIVE) and integrated approaches to testing and assessment (IATA) under the adverse outcome pathway (AOP) framework. Together, these alternatives offer a strong toolbox to support functional exposomics to study toxicity and causal mediators underpinning exposure-disease links. https://doi.org/10.1289/EHP13120.
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Affiliation(s)
- Yunjia Lai
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Muhammet Ay
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Carolina Duarte Hospital
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Souvarish Sarkar
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, USA
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Rogers E, Breathwaite EK, Nguyen-Jones T, Anderson SM, Odanga JJ, Parks DT, Wolf KK, Stone T, Balbuena P, Chen J, Presnell SC, Weaver JR, LeCluyse EL. Characterization of a human thyroid microtissue model for testing thyroid disrupting chemicals. FRONTIERS IN TOXICOLOGY 2024; 6:1408808. [PMID: 39114631 PMCID: PMC11303298 DOI: 10.3389/ftox.2024.1408808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/13/2024] [Indexed: 08/10/2024] Open
Abstract
Perturbation of thyroid hormone (T4) synthesis is known to cause numerous developmental, metabolic, and cognitive disorders in humans. Due to species differences in sensitivity to chemical exposures, there is a need for human-based in vitro approaches that recapitulate thyroid cellular architecture and T4 production when screening. To address these limitations, primary human thyrocytes, isolated from healthy adult donor tissues and cryopreserved at passage one (p'1) were characterized for cellular composition, 3D follicular architecture, and thyroglobulin (TG)/T4 expression and inhibition by prototype thyroid disrupting chemicals (TDC). Flow analysis of the post-thaw cell suspension showed >80% EpCAM-positive cells with 10%-50% CD90-positive cells. When seeded onto 96-well Matrigel®-coated plates and treated with bovine thyroid stimulating hormone (TSH), thyrocytes formed 3D microtissues during the initial 4-5 days of culture. The microtissues exhibited a stable morphology and size over a 14-day culture period. TG and T4 production were highest in microtissues when the proportion of CD90-positive cells, seeding density and thyroid stimulating hormone concentrations were between 10%-30%, 6K-12K cells per well, and 0.03-1 mIU/mL, respectively. At maximal TG and T4 production levels, average microtissue diameters ranged between 50 and 200 µm. The T4 IC50 values for two prototype TPO inhibitors, 6-propyl-2-thiouracil and methimazole, were ∼0.7 µM and ∼0.5 µM, respectively, in microtissue cultures treated between days 9 and 14. Overall, p'1 cryopreserved primary human thyrocytes in 3D microtissue culture represent a promising new model system to prioritize potential TDC acting directly on the thyroid as part of a weight-of-evidence hazard characterization.
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Affiliation(s)
- E. Rogers
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - E. K. Breathwaite
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - T. Nguyen-Jones
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - S. M. Anderson
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - J. J. Odanga
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - D. T. Parks
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - K. K. Wolf
- Research and Development, LifeSciences Division, LifeNet Health, Research Triangle Park, NC, United States
| | - T. Stone
- Research and Development, LifeSciences Division, LifeNet Health, Research Triangle Park, NC, United States
| | - P. Balbuena
- Research and Development, LifeSciences Division, LifeNet Health, Research Triangle Park, NC, United States
| | - J. Chen
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - S. C. Presnell
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - J. R. Weaver
- Research and Development, LifeSciences Division, LifeNet Health, Va Beach, VA, United States
| | - E. L. LeCluyse
- Research and Development, LifeSciences Division, LifeNet Health, Research Triangle Park, NC, United States
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Foley B, Hopperstad K, Gamble J, Lynn SG, Thomas RS, Deisenroth C. Technical evaluation and standardization of the human thyroid microtissue assay. Toxicol Sci 2024; 199:89-107. [PMID: 38310358 DOI: 10.1093/toxsci/kfae014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2024] Open
Abstract
The success and sustainability of U.S. EPA efforts to reduce, refine, and replace in vivo animal testing depends on the ability to translate toxicokinetic and toxicodynamic data from in vitro and in silico new approach methods (NAMs) to human-relevant exposures and health outcomes. Organotypic culture models employing primary human cells enable consideration of human health effects and inter-individual variability but present significant challenges for test method standardization, transferability, and validation. Increasing confidence in the information provided by these in vitro NAMs requires setting appropriate performance standards and benchmarks, defined by the context of use, to consider human biology and mechanistic relevance without animal data. The human thyroid microtissue (hTMT) assay utilizes primary human thyrocytes to reproduce structural and functional features of the thyroid gland that enable testing for potential thyroid-disrupting chemicals. As a variable-donor assay platform, conventional principles for assay performance standardization need to be balanced with the ability to predict a range of human responses. The objectives of this study were to (1) define the technical parameters for optimal donor procurement, primary thyrocyte qualification, and performance in the hTMT assay, and (2) set benchmark ranges for reference chemical responses. Thyrocytes derived from a cohort of 32 demographically diverse euthyroid donors were characterized across a battery of endpoints to evaluate morphological and functional variability. Reference chemical responses were profiled to evaluate the range and chemical-specific variability of donor-dependent effects within the cohort. The data-informed minimum acceptance criteria for donor qualification and set benchmark parameters for method transfer proficiency testing and validation of assay performance.
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Affiliation(s)
- Briana Foley
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Kristen Hopperstad
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - John Gamble
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831, USA
| | - Scott G Lynn
- Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington, District of Columbia 20460, USA
| | - Russell S Thomas
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Chad Deisenroth
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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Degitz SJ, Olker JH, Denny JS, Degoey PP, Hartig PC, Cardon MC, Eytcheson SA, Haselman JT, Mayasich SA, Hornung MW. In vitro screening of per- and polyfluorinated substances (PFAS) for interference with seven thyroid hormone system targets across nine assays. Toxicol In Vitro 2024; 95:105762. [PMID: 38072180 PMCID: PMC11081714 DOI: 10.1016/j.tiv.2023.105762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/31/2023] [Accepted: 12/05/2023] [Indexed: 12/30/2023]
Abstract
The US Environmental Protection Agency is evaluating the ecological and toxicological effects of per- and polyfluorinated chemicals. A number of perfluorinated chemicals have been shown to impact the thyroid axis in vivo suggesting that the thyroid hormone system is a target of these chemicals. The objective of this study was to evaluate the activity of 136 perfluorinated chemicals at seven key molecular initiating events (MIE) within the thyroid axis using nine in vitro assays. The potential MIE targets investigated are Human Iodothyronine Deiodinase 1 (hDIO1), Human Iodothyronine Deiodinase 2 (hDIO2), Human Iodothyronine Deiodinase 3 (hDIO3), Xenopus Iodothyronine Deiodinase (xDIO3); Human Iodotyrosine Deiodinase (hIYD), Xenopus Iodotyrosine Deiodinase (xIYD), Human Thyroid Peroxidase (hTPO); and the serum binding proteins Human Transthyretin (hTTR) and Human Thyroxine Binding Globulin (hTBG). Of the 136 PFAS chemicals tested, 85 had sufficient activity to produce a half-maximal effect concentration (EC50) in at least one of the nine assays. In general, most of these PFAS chemicals did not have strong potency towards the seven MIEs examined, apart from transthyretin binding, for which several PFAS had potency similar to the respective model inhibitor. These data sets identify potentially active PFAS chemicals to prioritize for further testing in orthogonal in vitro assays and at higher levels of biological organization to evaluate their capacity for altering the thyroid hormone system and causing potential adverse health and ecological effects.
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Affiliation(s)
- Sigmund J Degitz
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA.
| | - Jennifer H Olker
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Jeffery S Denny
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Philip P Degoey
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Phillip C Hartig
- US Environmental Protection Agency, Office of Research and Development Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27709, USA
| | - Mary C Cardon
- US Environmental Protection Agency, Office of Research and Development Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27709, USA
| | - Stephanie A Eytcheson
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Jonathan T Haselman
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Sally A Mayasich
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Michael W Hornung
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
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Eytcheson SA, Olker JH, Friedman KP, Hornung MW, Degitz SJ. Assessing utility of thyroid in vitro screening assays through comparisons to observed impacts in vivo. Regul Toxicol Pharmacol 2023; 144:105491. [PMID: 37666444 DOI: 10.1016/j.yrtph.2023.105491] [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: 01/05/2023] [Revised: 08/22/2023] [Accepted: 08/30/2023] [Indexed: 09/06/2023]
Abstract
To better understand endocrine disruption, the U.S. Environmental Protection Agency's (USEPA) Endocrine Disruptor Screening Program (EDSP) utilizes a two-tiered approach to investigate the potential of a chemical to interact with the estrogen, androgen, or thyroid systems. As in vivo testing lacks the throughput to address data gaps on endocrine bioactivity for thousands of chemicals, in vitro high-throughput screening (HTS) methods are being developed to screen larger chemical libraries. The primary objective of this work was to investigate for how many of the 52 chemicals with weight-of-evidence (WoE) determinations from EDSP Tier 1 screening there are available in vitro HTS data supporting a thyroid impact. HTS data from the USEPA ToxCast program and the EDSP WoE were collected for this analysis. Considering the complexity of endocrine disruption and interpreting HTS data, concordance between in vitro activity and in vivo effects ranges from 58 to 78%. Based on this evaluation, we conclude that the current suite of HTS assays is beneficial for prioritizing chemicals for further inquiry; however, without a more detailed analysis, one cannot conclude whether HTS results are the primary mode-of-action. Furthermore, development of in vitro assays for additional thyroid-relevant molecular initiating events is required to effectively predict in vivo thyroid impacts.
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Affiliation(s)
- Stephanie A Eytcheson
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA; U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, 55804, USA
| | - Jennifer H Olker
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, 55804, USA
| | - Katie Paul Friedman
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Research Triangle Park, NC, 27711, USA
| | - Michael W Hornung
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, 55804, USA
| | - Sigmund J Degitz
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, 55804, USA.
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8
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Haigis AC, Vergauwen L, LaLone CA, Villeneuve DL, O'Brien JM, Knapen D. Cross-species applicability of an adverse outcome pathway network for thyroid hormone system disruption. Toxicol Sci 2023; 195:1-27. [PMID: 37405877 DOI: 10.1093/toxsci/kfad063] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023] Open
Abstract
Thyroid hormone system disrupting compounds are considered potential threats for human and environmental health. Multiple adverse outcome pathways (AOPs) for thyroid hormone system disruption (THSD) are being developed in different taxa. Combining these AOPs results in a cross-species AOP network for THSD which may provide an evidence-based foundation for extrapolating THSD data across vertebrate species and bridging the gap between human and environmental health. This review aimed to advance the description of the taxonomic domain of applicability (tDOA) in the network to improve its utility for cross-species extrapolation. We focused on the molecular initiating events (MIEs) and adverse outcomes (AOs) and evaluated both their plausible domain of applicability (taxa they are likely applicable to) and empirical domain of applicability (where evidence for applicability to various taxa exists) in a THSD context. The evaluation showed that all MIEs in the AOP network are applicable to mammals. With some exceptions, there was evidence of structural conservation across vertebrate taxa and especially for fish and amphibians, and to a lesser extent for birds, empirical evidence was found. Current evidence supports the applicability of impaired neurodevelopment, neurosensory development (eg, vision) and reproduction across vertebrate taxa. The results of this tDOA evaluation are summarized in a conceptual AOP network that helps prioritize (parts of) AOPs for a more detailed evaluation. In conclusion, this review advances the tDOA description of an existing THSD AOP network and serves as a catalog summarizing plausible and empirical evidence on which future cross-species AOP development and tDOA assessment could build.
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Affiliation(s)
- Ann-Cathrin Haigis
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Lucia Vergauwen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Carlie A LaLone
- Great Lakes Toxicology and Ecology Division, United States Environmental Protection Agency, Duluth, Minnesota 55804, USA
| | - Daniel L Villeneuve
- Great Lakes Toxicology and Ecology Division, United States Environmental Protection Agency, Duluth, Minnesota 55804, USA
| | - Jason M O'Brien
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Dries Knapen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
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9
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Melching-Kollmuss S, Bothe K, Charlton A, Gangadharan B, Ghaffari R, Jacobi S, Marty S, Marxfeld HA, McInnes EF, Sauer UG, Sheets LP, Strupp C, Tinwell H, Wiemann C, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny - Part IV: the ECETOC and CLE Proposal for a Thyroid Function-Related Neurodevelopmental Toxicity Testing and Assessment Scheme (Thyroid-NDT-TAS). Crit Rev Toxicol 2023; 53:339-371. [PMID: 37554099 DOI: 10.1080/10408444.2023.2231033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/22/2023] [Accepted: 06/22/2023] [Indexed: 08/10/2023]
Abstract
Following the European Commission Endocrine Disruptor Criteria, substances shall be considered as having endocrine disrupting properties if they (a) elicit adverse effects, (b) have endocrine activity, and (c) the two are linked by an endocrine mode-of-action (MoA) unless the MoA is not relevant for humans. A comprehensive, structured approach to assess whether substances meet the Endocrine Disruptor Criteria for the thyroid modality (EDC-T) is currently unavailable. Here, the European Centre for Ecotoxicology and Toxicology of Chemicals Thyroxine Task Force and CropLife Europe propose a Thyroid Function-Related Neurodevelopmental Toxicity Testing and Assessment Scheme (Thyroid-NDT-TAS). In Tier 0, before entering the Thyroid-NDT-TAS, all available in vivo, in vitro and in silico data are submitted to weight-of-evidence (WoE) evaluations to determine whether the substance of interest poses a concern for thyroid disruption. If so, Tier 1 of the Thyroid-NDT-TAS includes an initial MoA and human relevance assessment (structured by the key events of possibly relevant adverse outcome pathways) and the generation of supportive in vitro/in silico data, if relevant. Only if Tier 1 is inconclusive, Tier 2 involves higher-tier testing to generate further thyroid- and/or neurodevelopment-related data. Tier 3 includes the final MoA and human relevance assessment and an overarching WoE evaluation to draw a conclusion on whether, or not, the substance meets the EDC-T. The Thyroid-NDT-TAS is based on the state-of-the-science, and it has been developed to minimise animal testing. To make human safety assessments more accurate, it is recommended to apply the Thyroid-NDT-TAS during future regulatory assessments.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Ursula G Sauer
- Scientific Consultancy - Animal Welfare, Neubiberg, Germany
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Huang L, Zhang Z, Xing H, Luo Y, Yang J, Sui X, Wang Y. Risk assessment based on dose-responsive and time-responsive genes to build PLS-DA models for exogenously induced lung injury. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 256:114891. [PMID: 37054470 DOI: 10.1016/j.ecoenv.2023.114891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 02/28/2023] [Accepted: 04/08/2023] [Indexed: 06/19/2023]
Abstract
Xenobiotics can easily harm human lungs owing to the openness of the respiratory system. Identifying pulmonary toxicity remains challenging owing to several reasons: 1) no biomarkers for pulmonary toxicity are available that might help to detect lung injury; 2) traditional animal experiments are time-consuming; 3) traditional detection methods solely focus on poisoning accidents; 4) analytical chemistry methods hardly achieve universal detection. An in vitro testing system able to identify the pulmonary toxicity of contaminants from food, the environment, and drugs is urgently needed. Compounds are virtually infinite, whereas toxicological mechanisms are countable. Therefore, universal methods to identify and predict the risks of contaminants can be designed based on these well-known toxicity mechanisms. In this study, we established a dataset based on transcriptome sequencing of A549 cells upon treatment with different compounds. The representativeness of our dataset was analyzed using bioinformatics methods. Artificial intelligence methods, namely partial least squares discriminant analysis (PLS-DA) models, were employed for toxicity prediction and toxicant identification. The developed model predicted the pulmonary toxicity of compounds with a 92 % accuracy. These models were submitted to an external validation using highly heterogeneous compounds, which supported the accuracy and robustness of our developed methodology. This assay exhibits universal potential applications for water quality monitoring, crop pollution detection, food and drug safety evaluation, as well as chemical warfare agent detection.
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Affiliation(s)
- Lijuan Huang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China
| | - Zinan Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China
| | - Huanchun Xing
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China
| | - Yuan Luo
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China
| | - Jun Yang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China
| | - Xin Sui
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China.
| | - Yongan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China.
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11
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Mitchell CA, Burden N, Bonnell M, Hecker M, Hutchinson TH, Jagla M, LaLone CA, Lagadic L, Lynn SG, Shore B, Song Y, Vliet SM, Wheeler JR, Embry MR. New Approach Methodologies for the Endocrine Activity Toolbox: Environmental Assessment for Fish and Amphibians. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:757-777. [PMID: 36789969 PMCID: PMC10258674 DOI: 10.1002/etc.5584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/07/2022] [Accepted: 02/06/2023] [Indexed: 06/14/2023]
Abstract
Multiple in vivo test guidelines focusing on the estrogen, androgen, thyroid, and steroidogenesis pathways have been developed and validated for mammals, amphibians, or fish. However, these tests are resource-intensive and often use a large number of laboratory animals. Developing alternatives for in vivo tests is consistent with the replacement, reduction, and refinement principles for animal welfare considerations, which are supported by increasing mandates to move toward an "animal-free" testing paradigm worldwide. New approach methodologies (NAMs) hold great promise to identify molecular, cellular, and tissue changes that can be used to predict effects reliably and more efficiently at the individual level (and potentially on populations) while reducing the number of animals used in (eco)toxicological testing for endocrine disruption. In a collaborative effort, experts from government, academia, and industry met in 2020 to discuss the current challenges of testing for endocrine activity assessment for fish and amphibians. Continuing this cross-sector initiative, our review focuses on the current state of the science regarding the use of NAMs to identify chemical-induced endocrine effects. The present study highlights the challenges of using NAMs for safety assessment and what work is needed to reduce their uncertainties and increase their acceptance in regulatory processes. We have reviewed the current NAMs available for endocrine activity assessment including in silico, in vitro, and eleutheroembryo models. New approach methodologies can be integrated as part of a weight-of-evidence approach for hazard or risk assessment using the adverse outcome pathway framework. The development and utilization of NAMs not only allows for replacement, reduction, and refinement of animal testing but can also provide robust and fit-for-purpose methods to identify chemicals acting via endocrine mechanisms. Environ Toxicol Chem 2023;42:757-777. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
| | - Natalie Burden
- National Centre for the 3Rs (NC3Rs), London, United Kingdom
| | - Mark Bonnell
- Environment and Climate Change Canada, Ottawa, Canada
| | - Markus Hecker
- Toxicology Centre and School of the Environment & Sustainability, University of Saskatchewan, Saskatoon, Canada
| | | | | | - Carlie A. LaLone
- Office of Research and Development, Great Lakes Toxicology & Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Laurent Lagadic
- Research and Development, Crop Science, Environmental Safety, Bayer, Monheim am Rhein, Germany
| | - Scott G. Lynn
- Office of Pesticide Programs, US Environmental Protection Agency, Washington, DC
| | - Bryon Shore
- Environment and Climate Change Canada, Ottawa, Canada
| | - You Song
- Norwegian Institute for Water Research, Oslo, Norway
| | - Sara M. Vliet
- Office of Research and Development, Scientific Computing and Data Curation Division, US Environmental Protection Agency, Duluth, Minnesota
| | | | - Michelle R. Embry
- The Health and Environmental Sciences Institute, Washington, DC, USA
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12
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Stoker TE, Wang J, Murr AS, Bailey JR, Buckalew AR. High-Throughput Screening of ToxCast PFAS Chemical Library for Potential Inhibitors of the Human Sodium Iodide Symporter. Chem Res Toxicol 2023; 36:380-389. [PMID: 36821091 DOI: 10.1021/acs.chemrestox.2c00339] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Over the past decade, there has been increased concern for environmental chemicals that can target various sites within the hypothalamic-pituitary-thyroid axis to potentially disrupt thyroid synthesis, transport, metabolism, and/or function. One well-known thyroid target in both humans and wildlife is the sodium iodide symporter (NIS) that regulates iodide uptake into the thyroid gland, the first step of thyroid hormone synthesis. Our laboratory previously developed and validated a radioactive iodide uptake (RAIU) high-throughput assay in a stably transduced human NIS cell line (hNIS-HEK293T-EPA) to identify chemicals with potential for NIS inhibition. So far, we have tested over 2000 chemicals (US EPA's ToxCast chemical libraries PI_v2, PII, and e1K) and discovered a subset of chemicals that significantly inhibit iodide uptake in the hNIS assay. Here, we utilized this screening assay to test a set of 149 unique per- and polyfluoroalkyl substances (PFAS) (ToxCast PFAS library) for potential NIS inhibition. For this evaluation, the 149 blinded samples were screened in a tiered approach, first in an initial single-concentration (≤100 μM) RAIU assay and subsequent evaluation of the chemicals that produced ≥20% inhibition using multiconcentration (MC) response (0.001-100 μM) testing in parallel RAIU and cell viability assays. Of this set, 38 of the PFAS chemicals inhibited iodide uptake ≥20% in the MC testing with 25 displaying inhibition ≥50%. To prioritize the most potent PFAS NIS inhibitors in this set, chemicals were ranked based on outcomes of both iodide uptake and cytotoxicity and normalized to perchlorate, a known positive control. Consistent with previous findings, PFOS and PFHxS were again found to be potent NIS inhibitors, yet significant inhibition was also observed for several other screened PFAS chemicals. Although further studies are clearly warranted, this initial screening effort identifies NIS as a molecular target for potential thyroid disruption by this persistent and structurally diverse class of chemicals.
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Affiliation(s)
- Tammy E Stoker
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Jun Wang
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
- Oak Ridge Institute for Science and Education, US Department of Energy, Oak Ridge, Tennessee 37831, United States
| | - Ashley S Murr
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Jarod R Bailey
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
- Oak Ridge Institute for Science and Education, US Department of Energy, Oak Ridge, Tennessee 37831, United States
| | - Angela R Buckalew
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
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13
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Staveley JP, Freeman EL, McArdle ME, Ortego LS, Coady KK, Bone A, Lagadic L, Weltje L, Weyers A, Wheeler JR. Current testing programs for pesticides adequately capture endocrine activity and adversity for protection of vertebrate wildlife. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2023. [PMID: 36597818 DOI: 10.1002/ieam.4732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
The toxicity and ecotoxicity of pesticide active ingredients are evaluated by a number of standardized test methods using vertebrate animals. These standard test methods are required under various regulatory programs for the registration of pesticides. Over the past two decades, additional test methods have been developed with endpoints that are responsive to endocrine activity and subsequent adverse effects. This article examines the available test methods and their endpoints that are relevant to an assessment of endocrine-disrupting properties of pesticides. Furthermore, the article highlights how weight-of-evidence approaches should be applied to determine whether an adverse response in (eco)toxicity tests is caused by an endocrine mechanism of action. The large number of endpoints in the current testing paradigms for pesticides make it unlikely that endocrine activity and adversity is being overlooked. Integr Environ Assess Manag 2023;00:1-21. © 2023 Bayer CropScience and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
| | | | | | - Lisa S Ortego
- Bayer Crop Science, Environmental Safety, Chesterfield, Missouri, USA
| | - Katherine K Coady
- Bayer Crop Science, Environmental Safety, Chesterfield, Missouri, USA
| | - Audrey Bone
- Bayer Crop Science, Environmental Safety, Chesterfield, Missouri, USA
| | - Laurent Lagadic
- Bayer AG, Crop Science, Environmental Safety, Monheim am Rhein, Germany
| | - Lennart Weltje
- BASF SE, Agricultural Solutions-Ecotoxicology, Limburgerhof, Germany
| | - Arnd Weyers
- Bayer AG, Crop Science, Environmental Safety, Monheim am Rhein, Germany
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14
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Finlayson KA, van de Merwe JP, Leusch FDL. Review of ecologically relevant in vitro bioassays to supplement current in vivo tests for whole effluent toxicity testing - Part 2: Non-apical endpoints. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158094. [PMID: 35987232 DOI: 10.1016/j.scitotenv.2022.158094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 08/03/2022] [Accepted: 08/13/2022] [Indexed: 06/15/2023]
Abstract
Whole effluent toxicity (WET) testing uses whole animal exposures to assess the toxicity of complex mixtures, like wastewater. These assessments typically include four apical endpoints: mortality, growth, development, and reproduction. In the last decade, there has been a shift to alternative methods that align with the 3Rs to replace, reduce, and refine the use of animals in research. In vitro bioassays can provide a cost-effective, high-throughput, ethical alternative to in vivo assays. In addition, they can potentially include additional, more sensitive, environmentally relevant endpoints than traditional toxicity tests. However, the ecological relevance of these endpoints must be established before they are adopted into regulatory frameworks. This is Part 2 of a two-part review that aims to identify in vitro bioassays that are linked to ecologically relevant endpoints that could be included in WET testing. Part 2 of this review focuses on non-apical endpoints that should be incorporated into WET testing. In addition to the four apical endpoints addressed in Part 1, this review identified seven additional toxic outcomes: endocrine disruption, xenobiotic metabolism, carcinogenicity, oxidative stress, inflammation, immunotoxicity and neurotoxicity. For each, the response at the molecular or cellular level measured in vitro was linked to the response at the organism level through a toxicity pathway. Literature from 2015 to 2020 was used to identify suitable bioassays that could be incorporated into WET testing.
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Affiliation(s)
| | - Jason P van de Merwe
- Australian Rivers Institute, Griffith University, Australia; School of Environment and Science, Griffith University, Gold Coast, Australia
| | - Frederic D L Leusch
- Australian Rivers Institute, Griffith University, Australia; School of Environment and Science, Griffith University, Gold Coast, Australia
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15
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Nakiwala D, Noyes PD, Faure P, Chovelon B, Corne C, Gauchez AS, Guergour D, Lyon-Caen S, Sakhi AK, Sabaredzovic A, Thomsen C, Pin I, Slama R, Philippat C. Phenol and Phthalate Effects on Thyroid Hormone Levels during Pregnancy: Relying on In Vitro Assays and Adverse Outcome Pathways to Inform an Epidemiological Analysis. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:117004. [PMID: 36350136 PMCID: PMC9645207 DOI: 10.1289/ehp10239] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 08/01/2022] [Accepted: 10/07/2022] [Indexed: 05/29/2023]
Abstract
BACKGROUND Studies characterizing associations between phenols, phthalates and thyroid hormones during pregnancy produce inconsistent results. This divergence may be partly attributable to false positives due to multiple comparison testing of large numbers of chemicals, and measurement error as studies rely on small numbers of biospecimens despite high intra-individual variability in urinary chemical metabolite concentrations. OBJECTIVES This study employs a priori chemical filtering and expanded urinary biomonitoring to evaluate associations between phenol/phthalate exposures and serum thyroid hormones assessed during pregnancy. METHODS A two-tiered approach was implemented: a) In vitro high-throughput screening results from the ToxCast/Tox21 database, as informed by a thyroid Adverse Outcome Pathway network, were evaluated to select phenols/phthalates with activity on known and putative molecular initiating events in the thyroid pathway; and b) Adjusted linear regressions were used to study associations between filtered compounds and serum thyroid hormones measured in 437 pregnant women recruited in Grenoble area (France) between 2014 and 2017. Phenol/phthalate metabolites were measured in repeated spot urine sample pools (median: 21 samples/women). RESULTS The ToxCast/Tox21 screening reduced the chemical set from 16 to 13 and the associated number of statistical comparisons by 19%. Parabens were negatively associated with free triiodothyronine (T3) and the T3/T4 (total thyroxine) ratio. Monobenzyl phthalate was positively associated with total T4 and negatively with the T3/T4 ratio. Effect modification by iodine status was detected for several compounds (among them ΣDEHP and mono-n-butyl phthalate) that were associated with some hormones among women with normal iodine levels. CONCLUSION For these chemicals, screening for compounds with an increased likelihood for thyroid-related effects and relying on repeated urine samples to assess exposures improved the overall performance of multichemical analyses of thyroid disruption. This approach may improve future evaluations of human data for the thyroid pathway with implication for fetal health and may serve as a model for evaluating other toxicity outcomes. https://doi.org/10.1289/EHP10239.
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Affiliation(s)
- Dorothy Nakiwala
- Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute for Advanced Biosciences (IAB), Institut national de la santé et de la recherche médicale (Inserm) U1209, Centre national de la recherche scientifique (CNRS) UMR 5309, Université Grenoble Alpes, Grenoble, France
| | - Pamela D. Noyes
- Center for Public Health and Environmental Assessment, Office of Research and Development (ORD), U.S. Environmental Protection Agency, Washington, District of Columbia, USA
| | - Patrice Faure
- Service de Biochimie SB2TE, Institut de Biologie et Pathologie CHU Grenoble Alpes, Université Grenoble Alpes, Grenoble, France
| | - Benoît Chovelon
- Service de Biochimie SB2TE, Institut de Biologie et Pathologie CHU Grenoble Alpes, Université Grenoble Alpes, Grenoble, France
- Département de Pharmacochimie Moleculaire, CNRS, UMR 5063, Université Grenoble Alpes, Grenoble, France
| | - Christelle Corne
- Service de Biochimie SB2TE, Institut de Biologie et Pathologie CHU Grenoble Alpes, Université Grenoble Alpes, Grenoble, France
| | - Anne Sophie Gauchez
- Service de Biochimie SB2TE, Institut de Biologie et Pathologie CHU Grenoble Alpes, Université Grenoble Alpes, Grenoble, France
| | - Dorra Guergour
- Service de Biochimie SB2TE, Institut de Biologie et Pathologie CHU Grenoble Alpes, Université Grenoble Alpes, Grenoble, France
| | - Sarah Lyon-Caen
- Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute for Advanced Biosciences (IAB), Institut national de la santé et de la recherche médicale (Inserm) U1209, Centre national de la recherche scientifique (CNRS) UMR 5309, Université Grenoble Alpes, Grenoble, France
| | - Amrit K. Sakhi
- Department of Food Safety, Norwegian Institute of Public Health, Oslo, Norway
| | | | - Cathrine Thomsen
- Department of Food Safety, Norwegian Institute of Public Health, Oslo, Norway
| | - Isabelle Pin
- Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute for Advanced Biosciences (IAB), Institut national de la santé et de la recherche médicale (Inserm) U1209, Centre national de la recherche scientifique (CNRS) UMR 5309, Université Grenoble Alpes, Grenoble, France
- Pediatric Department, Grenoble University Hospital, La Tronche, France
| | - Rémy Slama
- Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute for Advanced Biosciences (IAB), Institut national de la santé et de la recherche médicale (Inserm) U1209, Centre national de la recherche scientifique (CNRS) UMR 5309, Université Grenoble Alpes, Grenoble, France
| | - Claire Philippat
- Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute for Advanced Biosciences (IAB), Institut national de la santé et de la recherche médicale (Inserm) U1209, Centre national de la recherche scientifique (CNRS) UMR 5309, Université Grenoble Alpes, Grenoble, France
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16
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El-Masri H, Paul Friedman K, Isaacs K, Wetmore BA. Advances in computational methods along the exposure to toxicological response paradigm. Toxicol Appl Pharmacol 2022; 450:116141. [PMID: 35777528 PMCID: PMC9619339 DOI: 10.1016/j.taap.2022.116141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/27/2022] [Accepted: 06/23/2022] [Indexed: 10/17/2022]
Abstract
Human health risk assessment is a function of chemical toxicity, bioavailability to reach target biological tissues, and potential environmental exposure. These factors are complicated by many physiological, biochemical, physical and lifestyle factors. Furthermore, chemical health risk assessment is challenging in view of the large, and continually increasing, number of chemicals found in the environment. These challenges highlight the need to prioritize resources for the efficient and timely assessment of those environmental chemicals that pose greatest health risks. Computational methods, either predictive or investigative, are designed to assist in this prioritization in view of the lack of cost prohibitive in vivo experimental data. Computational methods provide specific and focused toxicity information using in vitro high throughput screening (HTS) assays. Information from the HTS assays can be converted to in vivo estimates of chemical levels in blood or target tissue, which in turn are converted to in vivo dose estimates that can be compared to exposure levels of the screened chemicals. This manuscript provides a review for the landscape of computational methods developed and used at the U.S. Environmental Protection Agency (EPA) highlighting their potentials and challenges.
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Affiliation(s)
- Hisham El-Masri
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA.
| | - Katie Paul Friedman
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Kristin Isaacs
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA
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17
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Wirth EK, Puengel T, Spranger J, Tacke F. Thyroid hormones as a disease modifier and therapeutic target in nonalcoholic steatohepatitis. Expert Rev Endocrinol Metab 2022; 17:425-434. [PMID: 35957531 DOI: 10.1080/17446651.2022.2110864] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/03/2022] [Indexed: 10/16/2022]
Abstract
INTRODUCTION Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and closely interconnected to the metabolic syndrome. Liver-specific and systemic signaling pathways orchestrating glucose and fatty acid metabolism contribute to intrahepatic accumulation of lipids and inflammatory processes eventually causing disease progression to nonalcoholic steatohepatitis (NASH), liver fibrosis, and cirrhosis. Since a high number of key regulatory genes regarding liver homeostasis are directly mediated via thyroid hormone (TH) signaling, targeting TH receptors (TRs) represent a promising therapeutic potential for the treatment of NAFLD. AREAS COVERED In this review, we elucidate the effects of TH on metabolic regulations in the liver via local availability and actions. We discuss recent advances and the potential impact of thyromimetics in basic research and clinical trials including liver-targeted and TRβ-specific agents for the treatment of NAFLD. EXPERT OPINION Unselective TR targeting can be accompanied by negative side effects due to high TRβ expression in other organs and TRα-mediated effects. Recent advances in drug development and the introduction of liver-targeted thyromimetics selectively activating TRβ such as Resmetirom (MGL-3196) and VK2809 bring new hope of translating the knowledge on local TH effects into effective hepatic lipid-clearing therapies against NASH.
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Affiliation(s)
- Eva K Wirth
- Department of Endocrinology and Metabolism, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Tobias Puengel
- Department of Hepatology & Gastroenterology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Joachim Spranger
- Department of Endocrinology and Metabolism, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Frank Tacke
- Department of Hepatology & Gastroenterology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
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18
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Olker JH, Korte JJ, Haselman JT, Hornung MW, Degitz SJ. Cross-species comparison of chemical inhibition of human and Xenopus iodotyrosine deiodinase. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 249:106227. [PMID: 35767922 PMCID: PMC9887787 DOI: 10.1016/j.aquatox.2022.106227] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 05/23/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The transition to include in vitro-based data in chemical hazard assessment has resulted in the development and implementation of screening assays to cover a diversity of biological pathways, including recently added assays to interrogate chemical disruption of proteins relevant to thyroid signaling pathways. Iodotyrosine deiodinase (IYD), the iodide recycling enzyme, is one such thyroid-relevant endpoint for which a human-based screening assay has recently been developed and used to screen large libraries of chemicals. Presented here is the development of an amphibian IYD inhibition assay and its implementation to conduct a cross-species comparison between chemical inhibition of mammalian and non-mammalian IYD enzyme activity. The successful development of an amphibian IYD inhibition assay was based on demonstration of sufficient IYD enzyme activity in several tissues collected from larval Xenopus laevis. With this new assay, 154 chemicals were tested in concentration-response to provide a basis for comparison of relative chemical potency to results obtained from the human IYD assay. Most chemicals exhibited similar inhibition in both assays, with less than 25% variation in median inhibition for 120 of 154 chemicals and 85% concordance in categorization of "active" (potential IYD inhibitor) versus "inactive". For chemicals that produced 50% or greater inhibition in both assays, rank-order potency was similar, with the majority of the IC50s varying by less than 2-fold (and all within an order of magnitude). Most differences resulted from greater maximum inhibition or higher chemical potency observed with human IYD. This strong cross-species agreement suggests that results from the human-based assay would be conservatively predictive of chemical effects on amphibian IYD.
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Affiliation(s)
- Jennifer H Olker
- Great Lakes Toxicology and Ecology Division, Office of Research and Development, Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN 55804, USA.
| | - Joseph J Korte
- Great Lakes Toxicology and Ecology Division, Office of Research and Development, Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN 55804, USA
| | - Jonathan T Haselman
- Great Lakes Toxicology and Ecology Division, Office of Research and Development, Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN 55804, USA
| | - Michael W Hornung
- Great Lakes Toxicology and Ecology Division, Office of Research and Development, Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN 55804, USA
| | - Sigmund J Degitz
- Great Lakes Toxicology and Ecology Division, Office of Research and Development, Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN 55804, USA
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19
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Yamauchi I, Sakane Y, Okuno Y, Sugawa T, Hakata T, Fujita H, Okamoto K, Taura D, Yamashita T, Hirota K, Ueda Y, Fujii T, Yasoda A, Inagaki N. High-throughput Screening in Combination With a Cohort Study for Iodothyronine Deiodinases. Endocrinology 2022; 163:6607576. [PMID: 35695766 DOI: 10.1210/endocr/bqac090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Indexed: 11/19/2022]
Abstract
Regulatory mechanisms of iodothyronine deiodinases (DIOs) require further elucidation, and conventional methods for evaluating DIOs are unsuitable for high-throughput screening (HTS). Here we explored factors of transcriptional regulation of 3 types of DIOs (DIO1, DIO2, and DIO3) from a chemical library using our designed HTS. We constructed HTS based on a promoter assay and performed a screen of 2480 bioactive compounds. For compounds that were clinically approved, we validated hit compounds through a retrospective cohort study in our department that evaluated changes in thyroid function in patients using the compounds as drug therapy. Furthermore, we verified the involvement of DIOs using mice treated with the compounds. Of the hit compounds, 6 and 7 compounds transcriptionally up- and downregulated DIO1, respectively; 34 transcriptionally upregulated DIO2; and 5 and 2 compounds transcriptionally up- and downregulated DIO3, respectively. The cohort study clarified the clinical effects of some hit compounds: ritodrine increased free triiodothyronine (fT3)/free thyroxine (fT4) ratio and decreased serum thyroid-stimulating hormone (TSH) levels, tadalafil increased serum fT3 levels, and tyrosine kinase inhibitors (TKIs) decreased serum fT3 and fT4 levels and increased serum TSH levels. Following in vivo experiments using treated mice, consistent results were observed in ritodrine, which upregulated DIO2 in the thyroid gland. In conclusion, we completed HTS for DIOs and obtained attractive hit compounds. Our cohort study revealed the clinical significance of ritodrine, sildenafil, and TKIs. We hope our unique method will contribute to analyzing various targets and lists of hit compounds will promote understanding of DIOs.
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Affiliation(s)
- Ichiro Yamauchi
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoriko Sakane
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Sugawa Clinic, Kyoto, Japan
| | - Yukiko Okuno
- Medical Research Support Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Taku Sugawa
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takuro Hakata
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Haruka Fujita
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kentaro Okamoto
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Daisuke Taura
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takafumi Yamashita
- Metabolism and Endocrinology Division of Internal Medicine, Kishiwada City Hospital, Osaka, Japan
| | - Keisho Hirota
- Department of Pathology and Biology of Diseases, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yohei Ueda
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toshihito Fujii
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihiro Yasoda
- Clinical Research Center, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
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20
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Renko K, Kerp H, Pape J, Rijntjes E, Burgdorf T, Führer D, Köhrle J. Tentative Application of a Streamlined Protocol to Determine Organ-Specific Regulations of Deiodinase 1 and Dehalogenase Activities as Readouts of the Hypothalamus-Pituitary-Thyroid-Periphery-Axis. FRONTIERS IN TOXICOLOGY 2022; 4:822993. [PMID: 35387426 PMCID: PMC8978789 DOI: 10.3389/ftox.2022.822993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/24/2022] [Indexed: 11/22/2022] Open
Abstract
In animal studies, both in basic science and in toxicological assessment of potential endocrine disruptors, the state of the thyroid hormone (TH) axis is often described and defined exclusively by the concentrations of circulating THs and TSH. Although it is known that the local, organ-specific effects of THs are also substantially regulated by local mechanisms such as TH transmembrane transport and metabolism of TH by deiodinases, such endpoint parameters of the axis are rarely assessed in these experiments. Currently developed in vitro assays utilize the Sandell-Kolthoff reaction, a photometric method of iodide determination, to test the effect of chemicals on iodotyrosine and iodothyronine deiodinases. Furthermore, this technology offers the possibility to determine the iodine content of various sample types (e.g., urine, ex vivo tissue) in a simple way. Here, we measured deiodinase type 1 and iodotyrosine dehalogenase activity by means of the Sandell-Kolthoff reaction in ex vivo samples of hypo- and hyperthyroid mice of two age groups (young; 3 months and old; 20 months). In thyroid, liver and kidney, organ-specific regulation patterns emerged across both age groups, which, based on this pilot study, may serve as a starting point for a deeper characterization of the TH system in relevant studies in the future and support the development of Integrated Approach for Testing and Assessment (IATA).
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Affiliation(s)
- Kostja Renko
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), Berlin, Germany
- Charité, Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, Berlin, Germany
- *Correspondence: Kostja Renko,
| | - Helena Kerp
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, Duisburg, Germany
| | - Janina Pape
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, Duisburg, Germany
| | - Eddy Rijntjes
- Charité, Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, Berlin, Germany
| | - Tanja Burgdorf
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), Berlin, Germany
| | - Dagmar Führer
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, Duisburg, Germany
| | - Josef Köhrle
- Charité, Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, Berlin, Germany
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21
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Haselman JT, Olker JH, Kosian PA, Korte JJ, Denny JS, Tietge JE, Hornung MW, Degitz SJ. Characterization of the mechanistic linkages between iodothyronine deiodinase inhibition and impaired thyroid-mediated growth and development in Xenopus laevis using iopanoic acid. Toxicol Sci 2022; 187:139-149. [PMID: 35179606 PMCID: PMC9254162 DOI: 10.1093/toxsci/kfac014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Iodothyronine deiodinases (DIO) are key enzymes that influence tissue-specific thyroid hormone levels during thyroid-mediated amphibian metamorphosis. Within the larger context of evaluating chemicals for thyroid system disrupting potential, chemical activity toward DIOs is being evaluated using high-throughput in vitro screening assays as part of U.S. EPA's ToxCast program. However, existing data gaps preclude any inferences between in vitro chemical inhibition of DIOs and in vivo outcomes relevant to ecological risk assessment. This study aimed to generate targeted data in a laboratory model species (Xenopus laevis) using a model DIO inhibitor, iopanoic acid (IOP), to characterize linkages between in vitro potency, in vivo biochemical responses, and adverse organismal outcomes. In vitro potency of IOP toward DIOs was evaluated using previously developed in vitro screening assays, which showed concentration-dependent inhibition of human DIO1 (IC50: 97 µM) and DIO2 (IC50: 231 µM) but did not inhibit human or X. laevis DIO3 under the assay conditions. In vivo exposure of larval X. laevis to 0, 2.6, 5.3 and 10.5 µM IOP caused thyroid-related biochemical profiles in the thyroid gland and plasma consistent with hyperthyroxinemia but resulted in delayed metamorphosis and significantly reduced growth in the highest two exposure concentrations. Independent evaluations of dio gene expression ontogeny, together with existing literature, supported interpretation of IOP-mediated effects resulting in a proposed adverse outcome pathway for DIO2 inhibition leading to altered amphibian metamorphosis. This study highlights the types of mechanistic data needed to move toward predicting in vivo outcomes of regulatory concern from in vitro bioactivity data.
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Affiliation(s)
- Jonathan T Haselman
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Jennifer H Olker
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Patricia A Kosian
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Joseph J Korte
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Jeffrey S Denny
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Joseph E Tietge
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Michael W Hornung
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
| | - Sigmund J Degitz
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
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22
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Huisinga M, Bertrand L, Chamanza R, Damiani I, Engelhardt J, Francke S, Freyberger A, Harada T, Harleman J, Kaufmann W, Keane K, Köhrle J, Lenz B, Marty MS, Melching-Kollmuss S, Palazzi X, Pohlmeyer-Esch G, Popp A, Rosol TJ, Strauss V, Van den Brink-Knol H, Wood CE, Yoshida M. Adversity Considerations for Thyroid Follicular Cell Hypertrophy and Hyperplasia in Nonclinical Toxicity Studies: Results From the 6th ESTP International Expert Workshop. Toxicol Pathol 2021; 48:920-938. [PMID: 33334259 DOI: 10.1177/0192623320972009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The European Society of Toxicologic Pathology organized an expert workshop in May 2018 to address adversity considerations related to thyroid follicular cell hypertrophy and/or hyperplasia (FCHH), which is a common finding in nonclinical toxicity studies that can have important implications for risk assessment of pharmaceuticals, food additives, and environmental chemicals. The broad goal of the workshop was to facilitate better alignment in toxicologic pathology and regulatory sciences on how to determine adversity of FCHH. Key objectives were to describe common mechanisms leading to thyroid FCHH and potential functional consequences; provide working criteria to assess adversity of FCHH in context of associated findings; and describe additional methods and experimental data that may influence adversity determinations. The workshop panel was comprised of representatives from the European Union, Japan, and the United States. Participants shared case examples illustrating issues related to adversity assessments of thyroid changes. Provided here are summary discussions, key case presentations, and panel recommendations. This information should increase consistency in the interpretation of adverse changes in the thyroid based on pathology findings in nonclinical toxicity studies, help integrate new types of biomarker data into the review process, and facilitate a more systematic approach to communicating adversity determinations in toxicology reports.
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Affiliation(s)
| | - Lise Bertrand
- 57146Charles River Laboratories, Saint-Germain-Nuelles, France
| | - Ronnie Chamanza
- 50148Janssen Pharmaceutical Companies of Johnson & Johnson, Beerse, Belgium
| | | | | | - Sabine Francke
- Center for Food Safety and Applied Nutrition (CFSAN), 4137US Food and Drug Administration, College Park, MD, USA
| | | | | | | | | | | | - Josef Köhrle
- 72217Charité University Medicine Berlin, Berlin, Germany
| | - Barbara Lenz
- Roche Pharma Research and Development, Basel, Switzerland
| | - M Sue Marty
- 540144The Dow Chemical Company, Midland, MI, USA
| | | | | | | | | | | | | | | | - Charles E Wood
- 6893Boehringer Ingelheim Pharmaceuticals Inc, Ridgefield, CT, USA
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23
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Haselman JT, Olker JH, Kosian PA, Korte JJ, Swintek JA, Denny JS, Nichols JW, Tietge JE, Hornung MW, Degitz SJ. Targeted Pathway-based In Vivo Testing Using Thyroperoxidase Inhibition to Evaluate Plasma Thyroxine as a Surrogate Metric of Metamorphic Success in Model Amphibian Xenopus laevis. Toxicol Sci 2021; 175:236-250. [PMID: 32176285 DOI: 10.1093/toxsci/kfaa036] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Chemical safety evaluation is in the midst of a transition from traditional whole-animal toxicity testing to molecular pathway-based in vitro assays and in silico modeling. However, to facilitate the shift in reliance on apical effects for risk assessment to predictive surrogate metrics having characterized linkages to chemical mechanisms of action, targeted in vivo testing is necessary to establish these predictive relationships. In this study, we demonstrate a means to predict thyroid-related metamorphic success in the model amphibian Xenopus laevis using relevant biochemical measurements during early prometamorphosis. The adverse outcome pathway for thyroperoxidase inhibition leading to altered amphibian metamorphosis was used to inform a pathway-based in vivo study design that generated response-response relationships. These causal relationships were used to develop Bayesian probabilistic network models that mathematically determine conditional dependencies between biochemical nodes and support the predictive capability of the biochemical profiles. Plasma thyroxine concentrations were the most predictive of metamorphic success with improved predictivity when thyroid gland sodium-iodide symporter gene expression levels (a compensatory response) were used in conjunction with plasma thyroxine as an additional regressor. Although thyroid-mediated amphibian metamorphosis has been studied for decades, this is the first time a predictive relationship has been characterized between plasma thyroxine and metamorphic success. Linking these types of biochemical surrogate metrics to apical outcomes is vital to facilitate the transition to the new paradigm of chemical safety assessments.
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Affiliation(s)
- Jonathan T Haselman
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Jennifer H Olker
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Patricia A Kosian
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Joseph J Korte
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Joseph A Swintek
- Badger Technical Services, Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Jeffrey S Denny
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - John W Nichols
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Joseph E Tietge
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Michael W Hornung
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
| | - Sigmund J Degitz
- Great Lakes Toxicology and Ecology Division, U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Duluth, Minnesota 55804
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24
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Marty S, Beekhuijzen M, Charlton A, Hallmark N, Hannas BR, Jacobi S, Melching-Kollmuss S, Sauer UG, Sheets LP, Strauss V, Urbisch D, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny - part II: how can key events of relevant adverse outcome pathways be addressed in toxicological assessments? Crit Rev Toxicol 2021; 51:328-358. [PMID: 34074207 DOI: 10.1080/10408444.2021.1910625] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The current understanding of thyroid-related adverse outcome pathways (AOPs) with adverse neurodevelopmental outcomes in mammals has been reviewed. This served to establish if standard rodent toxicity test methods and in vitro assays allow identifying thyroid-related modes-of-action potentially leading to adverse neurodevelopmental outcomes, and the human relevance of effects - in line with the European Commission's Endocrine Disruptor Criteria. The underlying hypothesis is that an understanding of the key events of relevant AOPs provides insight into differences in incidence, magnitude, or species sensitivity of adverse outcomes. The rodent studies include measurements of serum thyroid hormones, thyroid gland pathology and neurodevelopmental assessments, but do not directly inform on specific modes-of-action. Opportunities to address additional non-routine parameters reflecting critical events of AOPs in toxicological assessments are presented. These parameters appear relevant to support the identification of specific thyroid-related modes-of-action, provided that prevailing technical limitations are overcome. Current understanding of quantitative key event relationships is often weak, but would be needed to determine if the triggering of a molecular initiating event will ultimately result in an adverse outcome. Also, significant species differences in all processes related to thyroid hormone signalling are evident, but the biological implications thereof (including human relevance) are often unknown. In conclusion, careful consideration of the measurement (e.g. timing, method) and interpretation of additional non-routine parameters is warranted. These findings will be used in a subsequent paper to propose a testing strategy to identify if a substance may elicit maternal thyroid hormone imbalance and potentially also neurodevelopmental effects in the progeny.
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Affiliation(s)
- Sue Marty
- The Dow Chemical Company, Midland, MI, USA
| | | | | | | | | | | | | | - Ursula G Sauer
- Scientific Consultancy - Animal Welfare, Neubiberg, Germany
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25
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Mayasich SA, Korte JJ, Denny JS, Hartig PC, Olker JH, DeGoey P, O'Flanagan J, Degitz SJ, Hornung MW. Xenopus laevis and human type 3 iodothyronine deiodinase enzyme cross-species sensitivity to inhibition by ToxCast chemicals. Toxicol In Vitro 2021; 73:105141. [PMID: 33713820 DOI: 10.1016/j.tiv.2021.105141] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/12/2021] [Accepted: 03/08/2021] [Indexed: 11/15/2022]
Abstract
Deiodinase enzymes are critical for tissue-specific and temporal control of activation or inactivation of thyroid hormones during vertebrate development, including amphibian metamorphosis. We previously screened ToxCast chemicals for inhibitory activity toward human recombinant Type 3 iodothyronine deiodinase enzyme (hDIO3) and subsequently produced Xenopus laevis recombinant dio3 enzyme (Xldio3) with the goals to identify specific chemical inhibitors of Xldio3, to evaluate cross-species sensitivity and explore whether the human assay results are predictive of the amphibian. We identified a subset of 356 chemicals screened against hDIO3 to test against Xldio3, initially at a single concentration (200 μM), and further tested 79 in concentration-response mode. Most chemicals had IC50 values lower for hDIO3 than for Xldio3 and many had steep Hill slopes (a potential indication of non-specific inhibition). However, eight of the most potent chemicals are likely specific inhibitors, with IC50 values of 14 μM or less, Hill slopes near -1 and curves not significantly different between species likely due to conservation of catalytically active amino acids. Controlling for assay conditions, human in vitro screening results can be predictive of activity in the amphibian assay. This study lays the groundwork for future studies using recombinant non-mammalian proteins to test cross-species sensitivity to chemicals. DISCLAIMER: The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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Affiliation(s)
- Sally A Mayasich
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA; Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Joseph J Korte
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Jeffrey S Denny
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Phillip C Hartig
- Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jennifer H Olker
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Philip DeGoey
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Joseph O'Flanagan
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA; Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Sigmund J Degitz
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Michael W Hornung
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA.
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26
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Expanded high-throughput screening and chemotype-enrichment analysis of the phase II: e1k ToxCast library for human sodium-iodide symporter (NIS) inhibition. Arch Toxicol 2021; 95:1723-1737. [PMID: 33656581 DOI: 10.1007/s00204-021-03006-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/16/2021] [Indexed: 12/19/2022]
Abstract
The sodium-iodide symporter (NIS) mediates the uptake of iodide into the thyroid. Inhibition of NIS function by xenobiotics has been demonstrated to suppress circulating thyroid hormones and perturb related physiological functions. Until recently, few environmental chemicals had been screened for NIS inhibition activity. We previously screened over 1000 chemicals from the ToxCast Phase II (ph1v2 and ph2) libraries using an in vitro radioactive iodide uptake (RAIU) with the hNIS-HEK293T cell line to identify NIS inhibitors. Here, we broaden the chemical space by expanding screening to include the ToxCast e1k library (804 unique chemicals) with initial screening for RAIU at 1 × 10-4 M. Then 209 chemicals demonstrating > 20% RAIU inhibition were further tested in multiple-concentration, parallel RAIU and cell viability assays. This identified 55 chemicals as active, noncytotoxic RAIU inhibitors. Further cytotoxicity-adjusted potency scoring (with NaClO4 having a reference score of 200) revealed five chemicals with moderate to strong RAIU inhibition (scored > 100). These data were combined with our previous PhII screening data to produce binary hit-calls for ~ 1800 unique chemicals (PhII + e1k) with and without cytotoxicity filtering. Results were analyzed with a ToxPrint chemotype-enrichment workflow to identify substructural features significantly enriched in the NIS inhibition hit-call space. We assessed the applicability of enriched PhII chemotypes to prospectively predict NIS inhibition in the e1k dataset. Chemotype enrichments derived for the combined ~ 1800 dataset also identified additional enriched features, as well as chemotypes affiliated with cytotoxicity. These enriched chemotypes provide important new information that can support future data interpretation, structure-activity relationship, chemical use, and regulation.
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27
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A review of species differences in the control of, and response to, chemical-induced thyroid hormone perturbations leading to thyroid cancer. Arch Toxicol 2021; 95:807-836. [PMID: 33398420 DOI: 10.1007/s00204-020-02961-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 11/26/2020] [Indexed: 12/13/2022]
Abstract
This review summarises the current state of knowledge regarding the physiology and control of production of thyroid hormones, the effects of chemicals in perturbing their synthesis and release that result in thyroid cancer. It does not consider the potential neurodevelopmental consequences of low thyroid hormones. There are a number of known molecular initiating events (MIEs) that affect thyroid hormone synthesis in mammals and many chemicals are able to activate multiple MIEs simultaneously. AOP analysis of chemical-induced thyroid cancer in rodents has defined the key events that predispose to the development of rodent cancer and many of these will operate in humans under appropriate conditions, if they were exposed to high enough concentrations of the affecting chemicals. There are conditions however that, at the very least, would indicate significant quantitative differences in the sensitivity of humans to these effects, with rodents being considerably more sensitive to thyroid effects by virtue of differences in the biology, transport and control of thyroid hormones in these species as opposed to humans where turnover is appreciably lower and where serum transport of T4/T3 is different to that operating in rodents. There is heated debate around claimed qualitative differences between the rodent and human thyroid physiology, and significant reservations, both scientific and regulatory, still exist in terms of the potential neurodevelopmental consequences of low thyroid hormone levels at critical windows of time. In contrast, the situation for the chemical induction of thyroid cancer, through effects on thyroid hormone production and release, is less ambiguous with both theoretical, and actual data, showing clear dose-related thresholds for the key events predisposing to chemically induced thyroid cancer in rodents. In addition, qualitative differences in transport, and quantitative differences in half life, catabolism and turnover of thyroid hormones, exist that would not operate under normal situations in humans.
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28
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Olker JH, Korte JJ, Denny JS, Haselman JT, Hartig PC, Cardon MC, Hornung MW, Degitz SJ. In vitro screening for chemical inhibition of the iodide recycling enzyme, iodotyrosine deiodinase. Toxicol In Vitro 2020; 71:105073. [PMID: 33352258 DOI: 10.1016/j.tiv.2020.105073] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/25/2020] [Accepted: 12/17/2020] [Indexed: 02/07/2023]
Abstract
The iodide recycling enzyme, iodotyrosine deiodinase (IYD), is a largely unstudied molecular mechanism through which environmental chemicals can potentially cause thyroid disruption. This highly conserved enzyme plays an essential role in maintaining adequate levels of free iodide for thyroid hormone synthesis. Thyroid disruption following in vivo IYD inhibition has been documented in mammalian and amphibian models; however, few chemicals have been tested for IYD inhibition in either in vivo or in vitro assays. Presented here are the development and application of a screening assay to assess susceptibility of IYD to chemical inhibition. With recombinant human IYD enzyme, a 96-well plate in vitro assay was developed and then used to screen over 1800 unique substances from the U.S. EPA ToxCast screening library. Through a tiered screening approach, 194 IYD inhibitors were identified (inhibited IYD enzyme activity by 20% or greater at target concentration of 200 μM). 154 chemicals were further tested in concentration-response (0.032-200 μM) to determine IC50 and rank-order potency. This work broadens the coverage of thyroid-relevant molecular targets for chemical screening, provides the largest set of chemicals tested for IYD inhibition, and aids in prioritizing chemicals for targeted in vivo testing to evaluate thyroid-related adverse outcomes.
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Affiliation(s)
- Jennifer H Olker
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN 55804, USA.
| | - Joseph J Korte
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN 55804, USA
| | - Jeffrey S Denny
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN 55804, USA
| | - Jonathan T Haselman
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN 55804, USA
| | - Phillip C Hartig
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Research Triangle Park, North Carolina 27709, USA
| | - Mary C Cardon
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Research Triangle Park, North Carolina 27709, USA
| | - Michael W Hornung
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN 55804, USA
| | - Sigmund J Degitz
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN 55804, USA
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O'Shaughnessy KL, Gilbert ME. Thyroid disrupting chemicals and developmental neurotoxicity - New tools and approaches to evaluate hormone action. Mol Cell Endocrinol 2020; 518:110663. [PMID: 31760043 PMCID: PMC8270644 DOI: 10.1016/j.mce.2019.110663] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 12/25/2022]
Abstract
It is well documented that thyroid hormone (TH) action is critical for normal brain development and is mediated by both nuclear and extranuclear pathways. Given this dependence, the impact of environmental endocrine disrupting chemicals that interfere with thyroid signaling is a major concern with direct implications for children's health. However, identifying thyroid disrupting chemicals in vivo is primarily reliant on serum thyroxine (T4) measurements within greater developmental and reproductive toxicity assessments. These studies do not examine known TH-dependent phenotypes in parallel, which complicates chemical evaluation. Additionally, there exist no recommendations regarding what degree of serum T4 dysfunction is adverse, and little consideration is given to quantifying TH action within the developing brain. This review summarizes current testing strategies in rodent models and discusses new approaches for evaluating the developmental neurotoxicity of thyroid disrupting chemicals. This includes assays to identify adverse cellular effects of the brain by both immunohistochemistry and gene expression, which would compliment serum T4 measures. While additional experiments are needed to test the full utility of these approaches, incorporation of these cellular and molecular assays could enhance chemical evaluation in the regulatory arena.
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Affiliation(s)
- Katherine L O'Shaughnessy
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Toxicity Assessment Division, Endocrine Toxicology Branch, Research Triangle Park, NC, 27711, USA.
| | - Mary E Gilbert
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Toxicity Assessment Division, Endocrine Toxicology Branch, Research Triangle Park, NC, 27711, USA.
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Strupp C, Quesnot N, Weber-Parmentier C, Richert L, Bomann WH, Singh P. Weight of Evidence and Human Relevance Evaluation of the Benfluralin Mode of Action in Rats (Part II): Thyroid carcinogenesis. Regul Toxicol Pharmacol 2020; 117:104736. [PMID: 32798613 DOI: 10.1016/j.yrtph.2020.104736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 11/08/2022]
Abstract
Benfluralin is an herbicide of the dinitroaniline class used to control grasses and weeds. In a 2 year dietary study in rats, benfluralin increased incidences of thyroid follicular adenoma and carcinoma at high dietary concentrations (≥2500 ppm). The benfluralin toxicology database suggests the mode of action (MOA) is initiated by induction of liver metabolizing enzymes, particularly thyroid hormone specific UGTs, a major pathway for T4 clearance in rats. As reported with phenobarbital, this effect triggers negative feedback regulation, increasing thyroid stimulating hormone (TSH) release into circulating blood. When sustained over time, this leads to thyroid changes such as follicular hypertrophy, hyperplasia and thyroid follicular tumors with chronic exposures. The described MOA was previously established in rat studies with various chemical activators of xenobiotic receptors in the liver. It is generally considered as non-relevant in humans, due to differences between humans and rats in T4 turnover and susceptibility to this carcinogenic MOA. A structured methodology based on the IPCS/MOA/Human Relevance framework was used in the evaluation of available benfluralin data, and the conclusion was determined that the carcinogenic potential of benfluralin in the thyroid is not relevant in humans.
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Affiliation(s)
- Christian Strupp
- Gowan, Highlands House, Basingstoke Road, Spencers Wood Reading, Berkshire, RG7 1NT, United Kingdom.
| | - Nicolas Quesnot
- Charles River Laboratories Evreux, 27005, Evreux Cedex, France.
| | | | | | - Werner H Bomann
- ToxConsult®, 9393 W 110th Street, 51 Corporate Woods, Suite 500, Overland Park, KS, 66210, USA.
| | - Pramila Singh
- Charles River Laboratories Evreux, 27005, Evreux Cedex, France.
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Deisenroth C, Soldatow VY, Ford J, Stewart W, Brinkman C, LeCluyse EL, MacMillan DK, Thomas RS. Development of an In Vitro Human Thyroid Microtissue Model for Chemical Screening. Toxicol Sci 2020; 174:63-78. [PMID: 31808822 PMCID: PMC8061085 DOI: 10.1093/toxsci/kfz238] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Thyroid hormones (TH) are essential for regulating a number of diverse physiological processes required for normal growth, development, and metabolism. The US EPA Endocrine Disruptor Screening Program (EDSP) has identified several molecular thyroid targets relevant to hormone synthesis dynamics that have been adapted to high-throughput screening (HTS) assays to rapidly evaluate the ToxCast/Tox21 chemical inventories for potential thyroid disrupting chemicals (TDCs). The uncertainty surrounding the specificity of active chemicals identified in these screens and the relevance to phenotypic effects on in vivo human TH synthesis are notable data gaps for hazard identification of TDCs. The objective of this study was to develop a medium-throughput organotypic screening assay comprised of reconstructed human thyroid microtissues to quantitatively evaluate the disruptive effects of chemicals on TH production and secretion. Primary human thyroid cells procured from qualified euthyroid donors were analyzed for retention of NK2 homeobox 1 (NKX2-1), Keratin 7 (KRT7), and Thyroglobulin (TG) protein expression by high-content image analysis to verify enrichment of follicular epithelial cells. A direct comparison of 2-dimensional (2D) and 3-dimensional (3D) 96-well culture formats was employed to characterize the morphology, differential gene expression, TG production, and TH synthesis over the course of 20 days. The results indicate that modeling human thyroid cells in the 3D format was sufficient to restore TH synthesis not observed in the 2D culture format. Inhibition of TH synthesis in an optimized 3D culture format was demonstrated with reference chemicals for key molecular targets within the thyroid gland. Implementation of the assay may prove useful for interpreting phenotypic effects of candidate TDCs identified by HTS efforts currently underway in the EDSP.
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Affiliation(s)
- Chad Deisenroth
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
| | | | - Jermaine Ford
- Research Cores Unit, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, North Carolina 27711
| | - Wendy Stewart
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
| | - Cassandra Brinkman
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
| | | | - Denise K. MacMillan
- Research Cores Unit, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, North Carolina 27711
| | - Russell S. Thomas
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
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Evaluation of potential sodium-iodide symporter (NIS) inhibitors using a secondary Fischer rat thyroid follicular cell (FRTL-5) radioactive iodide uptake (RAIU) assay. Arch Toxicol 2020; 94:873-885. [PMID: 32065294 DOI: 10.1007/s00204-020-02664-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/03/2020] [Indexed: 12/29/2022]
Abstract
The Fischer rat thyroid follicular cell line (FRTL-5) endogenously expresses the sodium-iodide symporter (NIS) and has been used to identify environmental chemicals that perturb thyroid hormone homeostasis by disruption of NIS-mediated iodide uptake. Previously, a high-throughput radioactive iodide uptake (RAIU) screening assay incorporating the hNIS-HEK293T-EPA cell line was used to identify potential human NIS (hNIS) inhibitors in 1028 ToxCast Phase I (ph1_v2) and Phase II chemicals. In this study, the FRTL-5 cell line was evaluated and applied as a secondary RAIU assay coupled with cell viability assays to further prioritize highly active NIS inhibitors from the earlier screening. Assay validation with ten reference chemicals and performance assessment by chemical controls suggest the FRTL-5 based assays are robust and highly reproducible. Top-ranked chemicals from the ToxCast screening were then evaluated in both FRTL-5 and hNIS RAIU assays using newly sourced chemicals to strengthen the testing paradigm and to enable a rat vs. human species comparison. Eighteen of 29 test chemicals showed less than 1 order of magnitude difference in IC50 values between the two assays. Notably, two common perfluorinated compounds, perfluorooctanesulfonic acid (PFOS) and perfluorohexane sulfonate (PFHxS), demonstrated strong NIS inhibitory activity [IC50 - 6.45 (PFOS) and - 5.70 (PFHxS) log M in FRTL-5 RAIU assay]. In addition, several chemicals including etoxazole, methoxyfenozide, oxyfluorfen, triclocarban, mepanipyrim, and niclosamide also exhibited NIS inhibition with minimal cytotoxicity in both assays and are proposed for additional testing using short-term in vivo assays to characterize effects on thyroid hormone synthesis.
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Dong H, Godlewska M, Wade MG. A rapid assay of human thyroid peroxidase activity. Toxicol In Vitro 2020; 62:104662. [DOI: 10.1016/j.tiv.2019.104662] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 09/12/2019] [Accepted: 09/20/2019] [Indexed: 11/25/2022]
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Paul-Friedman K, Martin M, Crofton KM, Hsu CW, Sakamuru S, Zhao J, Xia M, Huang R, Stavreva DA, Soni V, Varticovski L, Raziuddin R, Hager GL, Houck KA. Limited Chemical Structural Diversity Found to Modulate Thyroid Hormone Receptor in the Tox21 Chemical Library. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:97009. [PMID: 31566444 PMCID: PMC6792352 DOI: 10.1289/ehp5314] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Thyroid hormone receptors (TRs) are critical endocrine receptors that regulate a multitude of processes in adult and developing organisms, and thyroid hormone disruption is of high concern for neurodevelopmental and reproductive toxicities in particular. To date, only a small number of chemical classes have been identified as possible TR modulators, and the receptors appear highly selective with respect to the ligand structural diversity. Thus, the question of whether TRs are an important screening target for protection of human and wildlife health remains. OBJECTIVE Our goal was to evaluate the hypothesis that there is limited structural diversity among environmentally relevant chemicals capable of modulating TR activity via the collaborative interagency Tox21 project. METHODS We screened the Tox21 chemical library (8,305 unique structures) in a quantitative high-throughput, cell-based reporter gene assay for TR agonist or antagonist activity. Active compounds were further characterized using additional orthogonal assays, including mammalian one-hybrid assays, coactivator recruitment assays, and a high-throughput, fluorescent imaging, nuclear receptor translocation assay. RESULTS Known agonist reference chemicals were readily identified in the TR transactivation assay, but only a single novel, direct agonist was found, the pharmaceutical betamipron. Indirect activation of TR through activation of its heterodimer partner, the retinoid-X-receptor (RXR), was also readily detected by confirmation in an RXR agonist assay. Identifying antagonists with high confidence was a challenge with the presence of significant confounding cytotoxicity and other, non-TR-specific mechanisms common to the transactivation assays. Only three pharmaceuticals-mefenamic acid, diclazuril, and risarestat-were confirmed as antagonists. DISCUSSION The results support limited structural diversity for direct ligand effects on TR and imply that other potential target sites in the thyroid hormone axis should be a greater priority for bioactivity screening for thyroid axis disruptors. https://doi.org/10.1289/EHP5314.
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Affiliation(s)
- Katie Paul-Friedman
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Matt Martin
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Kevin M Crofton
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Chia-Wen Hsu
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Washington, DC, USA
| | - Srilatha Sakamuru
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Jinghua Zhao
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Menghang Xia
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ruili Huang
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Diana A Stavreva
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Vikas Soni
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Lyuba Varticovski
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Razi Raziuddin
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Gordon L Hager
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Keith A Houck
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
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Noyes PD, Friedman KP, Browne P, Haselman JT, Gilbert ME, Hornung MW, Barone S, Crofton KM, Laws SC, Stoker TE, Simmons SO, Tietge JE, Degitz SJ. Evaluating Chemicals for Thyroid Disruption: Opportunities and Challenges with in Vitro Testing and Adverse Outcome Pathway Approaches. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:95001. [PMID: 31487205 PMCID: PMC6791490 DOI: 10.1289/ehp5297] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 07/01/2019] [Accepted: 08/13/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Extensive clinical and experimental research documents the potential for chemical disruption of thyroid hormone (TH) signaling through multiple molecular targets. Perturbation of TH signaling can lead to abnormal brain development, cognitive impairments, and other adverse outcomes in humans and wildlife. To increase chemical safety screening efficiency and reduce vertebrate animal testing, in vitro assays that identify chemical interactions with molecular targets of the thyroid system have been developed and implemented. OBJECTIVES We present an adverse outcome pathway (AOP) network to link data derived from in vitro assays that measure chemical interactions with thyroid molecular targets to downstream events and adverse outcomes traditionally derived from in vivo testing. We examine the role of new in vitro technologies, in the context of the AOP network, in facilitating consideration of several important regulatory and biological challenges in characterizing chemicals that exert effects through a thyroid mechanism. DISCUSSION There is a substantial body of knowledge describing chemical effects on molecular and physiological regulation of TH signaling and associated adverse outcomes. Until recently, few alternative nonanimal assays were available to interrogate chemical effects on TH signaling. With the development of these new tools, screening large libraries of chemicals for interactions with molecular targets of the thyroid is now possible. Measuring early chemical interactions with targets in the thyroid pathway provides a means of linking adverse outcomes, which may be influenced by many biological processes, to a thyroid mechanism. However, the use of in vitro assays beyond chemical screening is complicated by continuing limits in our knowledge of TH signaling in important life stages and tissues, such as during fetal brain development. Nonetheless, the thyroid AOP network provides an ideal tool for defining causal linkages of a chemical exerting thyroid-dependent effects and identifying research needs to quantify these effects in support of regulatory decision making. https://doi.org/10.1289/EHP5297.
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Affiliation(s)
- Pamela D Noyes
- National Center for Environmental Assessment, Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Washington, DC, USA
| | - Katie Paul Friedman
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Patience Browne
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Co-operation and Development (OECD), Paris, France
| | - Jonathan T Haselman
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Mary E Gilbert
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Michael W Hornung
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Stan Barone
- Office of Pollution Prevention and Toxics, Office of Chemical Safety and Pollution Prevention, U.S. EPA, Washington, DC, USA
| | - Kevin M Crofton
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Susan C Laws
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Tammy E Stoker
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Steven O Simmons
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Joseph E Tietge
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Sigmund J Degitz
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
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Coady K, Browne P, Embry M, Hill T, Leinala E, Steeger T, Maślankiewicz L, Hutchinson T. When Are Adverse Outcome Pathways and Associated Assays "Fit for Purpose" for Regulatory Decision-Making and Management of Chemicals? INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2019; 15:633-647. [PMID: 30908812 PMCID: PMC6771501 DOI: 10.1002/ieam.4153] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/07/2019] [Accepted: 03/22/2019] [Indexed: 05/11/2023]
Abstract
There have been increasing demands for chemical hazard and risk assessments in recent years. Chemical companies have expanded internal product stewardship initiatives, and jurisdictions have increased the regulatory requirements for the manufacture and sale of chemicals. There has also been a shift in chemical toxicity evaluations within the same time frame, with new methodologies being developed to improve chemical safety assessments for both human health and the environment. With increased needs for chemical assessments coupled with more diverse data streams from new technologies, regulators and others tasked with chemical management activities are faced with increasing workloads and more diverse types of data to consider. The Adverse Outcome Pathway (AOP) framework can be applied in different scenarios to integrate data and guide chemical assessment and management activities. In this paper, scenarios of how AOPs can be used to guide chemical management decisions during research and development, chemical registration, and subsequent regulatory activities such as prioritization and risk assessment are considered. Furthermore, specific criteria (e.g., the type and level of AOP complexity, confidence in the AOP, as well as external review and assay validation) are proposed to examine whether AOPs and associated tools are fit for purpose when applied in different contexts. Certain toxicity pathways are recommended as priority areas for AOP research and development, and the continued use of AOPs and defined approaches in regulatory activities are recommended. Furthermore, a call for increased outreach, education, and enhanced use of AOP databases is proposed to increase their utility in chemicals management. Integr Environ Assess Manag 2019;15:633-647. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Katie Coady
- Toxicology & Environmental Research & ConsultingDow Chemical CompanyMidlandMichiganUSA
| | - Patience Browne
- Environment, Health and Safety Division, Environment DirectorateOrganisation for Economic and Cooperative DevelopmentParisFrance
| | - Michelle Embry
- Health and Environmental Sciences InstituteWashingtonDCUSA
| | - Thomas Hill
- US Environmental Protection AgencyNational Health and Environmental Effects Research Laboratory, Research Triangle ParkNorth Carolina
| | - Eeva Leinala
- Environment, Health and Safety Division, Environment DirectorateOrganisation for Economic and Cooperative DevelopmentParisFrance
| | - Thomas Steeger
- US Environmental Protection Agency, Office of Pesticide ProgramsWashingtonDC
| | - Lidka Maślankiewicz
- National Institute of Public Health and the Environment (RIVM)Centre for Safety of Substances and Products, BilthovenThe Netherlands
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Wang J, Hallinger DR, Murr AS, Buckalew AR, Lougee RR, Richard AM, Laws SC, Stoker TE. High-throughput screening and chemotype-enrichment analysis of ToxCast phase II chemicals evaluated for human sodium-iodide symporter (NIS) inhibition. ENVIRONMENT INTERNATIONAL 2019; 126:377-386. [PMID: 30826616 PMCID: PMC9082575 DOI: 10.1016/j.envint.2019.02.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/14/2019] [Accepted: 02/07/2019] [Indexed: 05/26/2023]
Abstract
In support of the Endocrine Disruptor Screening Program (EDSP), the U.S.EPA's Office of Research and Development (ORD) is developing high-throughput screening (HTS) approaches to identify chemicals that alter target sites in the thyroid hormone (TH) pathway. The sodium iodide symporter (NIS) is a transmembrane glycoprotein that mediates iodide uptake into the thyroid as the initial step of TH biosynthesis. Previously, we screened 293 ToxCast chemicals (ph1v2) using a HEK293T cell line expressing human NIS in parallel radioactive iodide uptake (RAIU) and cell viability assays to identify potential environmental NIS inhibitors. Here, we expanded NIS inhibitor screening for a set of 768 ToxCast Phase II (ph2) chemicals, and applied a novel computational toxicology approach based on the ToxPrint chemotype to identify chemical substructures associated with NIS inhibition. Following single-concentration screening (at 1 × 10-4 M with a 20% inhibition cutoff), 235 samples (228 chemicals) were further tested in multiple-concentration (1 × 10-9 - 1 × 10-4 M) format in both RAIU and cell viability assays. The 167 chemicals that exhibited significant RAIU inhibition were then prioritized using combined RAIU and cell viability responses that were normalized relative to the known NIS inhibitor sodium perchlorate. Some of the highest ranked chemicals, such as PFOS, tributyltin chloride, and triclocarban, have been previously reported to be thyroid disruptors. In addition, several novel chemicals were identified as potent NIS inhibitors. The present results were combined with the previous ph1v2 screening results to produce two sets of binary hit-calls for 1028 unique chemicals, consisting of 273 positives exhibiting significant RAIU inhibition, and 63 positives following application of a cell viability filter. A ToxPrint chemotype-enrichment analysis identified >20 distinct chemical substructural features, represented in >60% of the active chemicals, as significantly enriched in each NIS inhibition hit-call space. A shared set of 9 chemotypes enriched in both hit-call sets indicates stable chemotype signals (insensitive to cytotoxicity filters) that can help guide structure-activity relationship (SAR) investigations and inform future research.
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Affiliation(s)
- Jun Wang
- Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA; Oak Ridge Institute for Science and Education, U.S. Department of Energy, Oak Ridge, TN 37831, USA
| | - Daniel R Hallinger
- Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Ashley S Murr
- Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Angela R Buckalew
- Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Ryan R Lougee
- Oak Ridge Institute for Science and Education, U.S. Department of Energy, Oak Ridge, TN 37831, USA; National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Ann M Richard
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Susan C Laws
- Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA.
| | - Tammy E Stoker
- Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA.
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Olker JH, Korte JJ, Denny JS, Hartig PC, Cardon MC, Knutsen CN, Kent PM, Christensen JP, Degitz SJ, Hornung MW. Screening the ToxCast Phase 1, Phase 2, and e1k Chemical Libraries for Inhibitors of Iodothyronine Deiodinases. Toxicol Sci 2019; 168:430-442. [PMID: 30561685 PMCID: PMC6520049 DOI: 10.1093/toxsci/kfy302] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Deiodinase enzymes play an essential role in converting thyroid hormones between active and inactive forms by deiodinating the pro-hormone thyroxine (T4) to the active hormone triiodothyronine (T3) and modifying T4 and T3 to inactive forms. Chemical inhibition of deiodinase activity has been identified as an important endpoint to include in screening chemicals for thyroid hormone disruption. To address the lack of data regarding chemicals that inhibit the deiodinase enzymes, we developed robust in vitro assays that utilized human deiodinase types 1, 2, and 3 and screened over 1800 unique chemicals from the U.S. EPA's ToxCast phase 1_v2, phase 2, and e1k libraries. Initial testing at a single concentration identified 411 putative deiodinase inhibitors that produced inhibition of 20% or greater in at least 1 of the 3 deiodinase assays, including chemicals that have not previously been shown to inhibit deiodinases. Of these, 228 chemicals produced enzyme inhibition of 50% or greater; these chemicals were further tested in concentration-response to determine relative potency. Comparisons across these deiodinase assays identified 81 chemicals that produced selective inhibition, with 50% inhibition or greater of only 1 of the deiodinases. This set of 3 deiodinase inhibition assays provides a significant contribution toward expanding the limited number of in vitro assays used to identify chemicals with the potential to interfere with thyroid hormone homeostasis. In addition, these results set the groundwork for development and evaluation of structure-activity relationships for deiodinase inhibition, and inform targeted selection of chemicals for further testing to identify adverse outcomes of deiodinase inhibition.
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Affiliation(s)
- Jennifer H. Olker
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Joseph J. Korte
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Jeffrey S. Denny
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Phillip C. Hartig
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Toxicity Assessment Division, Research Triangle Park, North Carolina 27709
| | - Mary C. Cardon
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Toxicity Assessment Division, Research Triangle Park, North Carolina 27709
| | - Carsten N. Knutsen
- Student Services Contractor to the U.S. EPA, NHEERL, Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Paige M. Kent
- ORAU Student Services Contractor to the U.S. EPA, NHEERL, Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Jessica P. Christensen
- ORAU Student Services Contractor to the U.S. EPA, NHEERL, Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Sigmund J. Degitz
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Mid-Continent Ecology Division, Duluth, Minnesota, 55804
| | - Michae1 W. Hornung
- U.S. Environmental Protection Agency, Duluth, Minnesota, 55804
- Office of Research and Development, Duluth, Minnesota, 55804
- National Health and Environmental Effects Research Laboratory, Duluth, Minnesota, 55804
- Mid-Continent Ecology Division, Duluth, Minnesota, 55804
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LaLone CA, Villeneuve DL, Doering JA, Blackwell BR, Transue TR, Simmons CW, Swintek J, Degitz SJ, Williams AJ, Ankley GT. Evidence for Cross Species Extrapolation of Mammalian-Based High-Throughput Screening Assay Results. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13960-13971. [PMID: 30351027 PMCID: PMC8283686 DOI: 10.1021/acs.est.8b04587] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
High-throughput screening (HTS) and computational technologies have emerged as important tools for chemical hazard identification. The US Environmental Protection Agency (EPA) launched the Toxicity ForeCaster (ToxCast) Program, which has screened thousands of chemicals in hundreds of mammalian-based HTS assays for biological activity. The data are being used to prioritize toxicity testing on those chemicals likely to lead to adverse effects. To use HTS assays in predicting hazard to both humans and wildlife, it is necessary to understand how broadly these data may be extrapolated across species. The US EPA Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS; https://seqapass.epa.gov/seqapass/ ) tool was used to assess conservation of the 484 protein targets represented in the suite of ToxCast assays and other HTS assays. To demonstrate the utility of the SeqAPASS data for guiding extrapolation, case studies were developed which focused on targets of interest to the US Endocrine Disruptor Screening Program and the Organisation for Economic Cooperation and Development. These case studies provide a line of evidence for conservation of endocrine targets across vertebrate species, with few exceptions, and demonstrate the utility of SeqAPASS for defining the taxonomic domain of applicability for HTS results and identifying organisms for suitable follow-up toxicity tests.
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Affiliation(s)
- Carlie A. LaLone
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804, USA
- Corresponding Author: Carlie A. LaLone:
| | - Daniel L. Villeneuve
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804, USA
| | - Jon A. Doering
- National Research Council, 6201 Congdon Blvd., Duluth, MN 55804, USA
| | - Brett R. Blackwell
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804, USA
| | - Thomas R. Transue
- CSRA Inc., 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Cody W. Simmons
- CSRA Inc., 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Joe Swintek
- Badger Technical Services, 6201 Congdon Blvd., Duluth, MN 55804, USA
| | - Sigmund J. Degitz
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804, USA
| | - Antony J. Williams
- US Environmental Protection Agency, Office of Research and Development, National Center for Computational Toxicology, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Gerald T. Ankley
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804, USA
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