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Song S, Li Y, Lv L, Dong M, Qin Z. Tetrabromobisphenol A exerts thyroid disrupting effects but has little overt impact on postnatal brain development and neurobehaviors in mice. J Environ Sci (China) 2024; 142:1-10. [PMID: 38527875 DOI: 10.1016/j.jes.2023.10.028] [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: 06/09/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 03/27/2024]
Abstract
Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant. There is evidence showing that TBBPA can exert thyroid disrupting effects in mammals, but different results were also reported, along with inconsistent reports regarding its neurotoxicity. Here, we investigated thyroid disrupting effects and neurotoxicity of TBBPA (5, 50, 500 µg/(kg·day)) to male mice following maternal and direct exposure through drinking water, with the anti-thyroid drug propylthiouracil (PTU) as the positive control. On postnatal day (PND) 15, we expectedly observed severe thyroid compensatory hyperplasia and cerebellar developmental retardation in PTU-treated pups. The highest dose of TBBPA also caused thyroid histological alteration but had no effects on cerebellar development in terms of Purkinje cell morphology and the thickness of the internal granular layer and the molecular layer of the cerebellum. During puberty and adulthood, the thyroid morphological alterations became more pronounced in the TBBPA-treated animals, accompanied by decreased serum thyroid hormone levels. Furthermore, the 50 and 500 µg/(kg·day) TBBPA groups showed a significant decrease in the serum level of serotonin, a neurotransmitter associated with anxiety behaviors. Correspondingly, the highest dose group displayed anxiety-like behaviors in the elevated plus-maze test on PND 35, but this neurobehavioral alteration disappeared on PND 56. Moreover, no changes in neurobehavioral parameters tested were found in TBBPA-treated animals at puberty and adulthood. Altogether, all observations show that TBBPA can exert thyroid disrupting effects but has little overt impact on brain development and neurobehaviors in mice, suggesting that thyroid disruption does not necessarily cause overtly adverse neurodevelopmental outcomes.
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Affiliation(s)
- Shilin Song
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuanyuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengqi Dong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Tsinghua University, Beijing 100084, China.
| | - Zhanfen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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Ramhøj L, Svingen T, Evrard B, Chalmel F, Axelstad M. Two thyroperoxidase-inhibiting chemicals induce shared transcriptional changes in hippocampus of developing rats. Toxicology 2024; 505:153822. [PMID: 38685447 DOI: 10.1016/j.tox.2024.153822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
Thyroid hormone (TH) system disrupting compounds can impair brain development by perturbing TH action during critical life stages. Human exposure to TH system disrupting chemicals is therefore of great concern. To better protect humans against such chemicals, sensitive test methods that can detect effects on the developing brain are critical. Worryingly, however, current test methods are not sensitive and specific towards TH-mediated effects. To address this shortcoming, we performed RNA-sequencing of rat brains developmentally exposed to two different thyroperoxidase (TPO) inhibiting compounds, the medical drug methimazole (MMI) or the pesticide amitrole. Pregnant and lactating rats were exposed to 8 and 16 mg/kg/day(d) MMI or 25 and 50 mg/kg/d amitrole from gestational day 7 until postnatal day 16. Bulk-RNA-seq was performed on hippocampus from the 16-day old male pups. MMI and amitrole caused pronounced changes to the transcriptomes; 816 genes were differentially expressed, and 425 gene transcripts were similarly affected by both chemicals. Functional terms indicate effects from key cellular functions to changes in cell development, migration and differentiation of several cell populations. Of the total number of DEGs, 106 appeared to form a consistent transcriptional fingerprint of developmental hypothyroidism as they were similarly and dose-dependently expressed across all treatment groups. Using a filtering system, we identified 20 genes that appeared to represent the most sensitive, robust and dose-dependent markers of altered TH-mediated brain development. These markers provide inputs to the adverse outcome pathway (AOP) framework where they, in the context of linking TPO inhibiting compounds to adverse cognitive function, can be used to assess altered gene expression in the hippocampus in rat toxicity studies.
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Affiliation(s)
- Louise Ramhøj
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
| | - Terje Svingen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Bertrand Evrard
- Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail), UMR_S 1085, Rennes, F-35000, France
| | - Frédéric Chalmel
- Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail), UMR_S 1085, Rennes, F-35000, France
| | - Marta Axelstad
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
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Wiklund L, Pípal M, Weiss J, Beronius A. Exploring a mechanism-based approach for the identification of endocrine disruptors using Adverse Outcome Pathways (AOPs) and New Approach Methodologies (NAMs) : A perfluorooctane sulfonic acid case study. Toxicology 2024; 504:153794. [PMID: 38580097 DOI: 10.1016/j.tox.2024.153794] [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: 02/08/2024] [Revised: 03/21/2024] [Accepted: 04/01/2024] [Indexed: 04/07/2024]
Abstract
Endocrine disruptors (EDs) pose a serious threat to human health and the environment and require a comprehensive evaluation to be identified. The identification of EDs require a substantial amount of data, both in vitro and in vivo, due to the current scientific criteria in the EU. At the same time, the EU strives to reduce animal testing due to concerns regarding animal welfare and sensitivity of animal studies to adequately detect adverse effects relevant for human health. Perfluorooctane sulfonic acid (PFOS) is a persistent organic pollutant that is suspected to be an ED based on academic research, however it is not identified as such from a regulatory perspective. It has previously been shown that PFOS has the potential to cause neurotoxicity as well as affect the thyroid system, and it is known that specific thyroid hormone levels are critical in the development of the brain during. In this work, the aim was to evaluate a mechanism-based approach to identify ED properties of PFOS based on the Adverse Outcome Pathway (AOP) framework and using New Approach Methods (NAMs), by comparing this approach to an ED assessment based on the currently available guidance document. An AOP network (AOPN) was generated for the thyroid modality, and AOPs leading to developmental neurotoxicity (DNT) were identified. A literature search and screening process based on the AOPN, and systematic review methodology, was performed, followed by a rigorous Weight-of-Evidence (WoE) assessment. Evidence was mapped back onto the AOPN used for the literature search, to identify possible endocrine Modes-of-Action (MoAs) for PFOS and data gaps in the two assessments. It could be concluded that PFOS fulfils the criteria for ED classification in the standard ED assessment, but not in the mechanism-based assessment. The need for quantitative information, such as quantitative AOPs, for the mechanism-based approach is discussed. The possibility of a directly neurotoxic alternative MoA was also highlighted based on available in vitro data. Opportunities and challenges with implementing AOPs and NAMs into the regulatory assessment of EDs, and assessing hazard in the Next Generation Risk Assessment, is discussed. This case study exploring the mechanism-based approach to ED identification represents an important step toward more accurate and predictive assessment of EDs based on AOPs and NAMs, and to the Next Generation Risk Assessment (NGRA) concept.
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Affiliation(s)
- Linus Wiklund
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Marek Pípal
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Jana Weiss
- Department of Environmental Science, Stockholm University, Stockholm, Sweden
| | - Anna Beronius
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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Minami K, Sato A, Tomiyama N, Ogata K, Kosaka T, Hojo H, Takahashi N, Suto H, Aoyama H, Yamada T. Prenatal test cohort of a modified rat comparative thyroid assay adding brain thyroid hormone measurements and histology but lowering group size appears able to detect disruption by sodium phenobarbital. Curr Res Toxicol 2024; 6:100168. [PMID: 38693933 PMCID: PMC11061706 DOI: 10.1016/j.crtox.2024.100168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/04/2024] [Accepted: 04/16/2024] [Indexed: 05/03/2024] Open
Abstract
The Comparative Thyroid Assay (CTA, USEPA) is a screening test for thyroid hormone (TH) disruption in peripheral blood of dams and offspring. Recently, we began investigating feasible improvements to the CTA by adding examination of offspring brain TH concentrations and brain histopathology. In addition, we hypothesize that the number of animals required could be reduced by 50 % while still maintaining sensitivity to characterize treatment related changes in THs. Previously, we showed that the prenatal test cohort of the modified CTA could detect 1000 ppm sodium phenobarbital (NaPB)-induced suppression of brain T3 (by 9 %) and T4 (by 33 %) with no significant changes in serum T3 and T4 (less than 8 %). In the current study we expanded the dose response in a prenatal test cohort. Pregnant SD rats (N = 10/group) were exposed to 0, 1000 or 1500 ppm NaPB in the diet from gestational days (GD) 6 to GD20. Serum THs concentrations in GD20 dams together with serum/brain THs concentrations and brain histopathology in the GD20 fetuses were examined. NaPB dose-dependently suppressed serum T3 (up to -26 %) and T4 (up to -44 %) in dams, with suppression of T3 in serum (up to -26 %) and brain (up to -18 %) and T4 in serum (up to -26 %) and brain (up to -29 %) of fetuses but without clear dose dependency. There were no remarkable findings that deviated significantly from controls in GD20 fetal brain by qualitative histopathology. Overall, the present study suggests that the prenatal test cohort of this modified CTA is able to detect the expected fetal TH disruptions by prenatal exposure to NaPB, while also reducing the number of animals used by 50 %, consistent with the results of our previous study. These findings add to the suggestion that lowering group sizes and adding endpoints may be a useful alternative to the original CTA design.
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Affiliation(s)
- Kenta Minami
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
| | - Akira Sato
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Naruto Tomiyama
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Keiko Ogata
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
| | - Tadashi Kosaka
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Hitoshi Hojo
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Naofumi Takahashi
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Hidenori Suto
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
| | - Hiroaki Aoyama
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Tomoya Yamada
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
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5
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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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Xing Y, Li Z, Wang J, Qu Y, Hu Q, Ji S, Chang X, Zhao F, Lv Y, Pan Y, Shi X, Dai J. Associations between serum per- and polyfluoroalkyl substances and thyroid hormones in Chinese adults: A nationally representative cross-sectional study. ENVIRONMENT INTERNATIONAL 2024; 184:108459. [PMID: 38320373 DOI: 10.1016/j.envint.2024.108459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/26/2023] [Accepted: 01/23/2024] [Indexed: 02/08/2024]
Abstract
Disruption of thyroid homeostasis has been indicated in human studies on the effects of per- and polyfluoroalkyl substances (PFASs). However, limited research exists on this topic within the general Chinese population. Based on a substantial and representative sample of the Chinese adult population, our study provides insight into how PFASs specifically affect thyroid homeostasis. The study included 10 853 participants, aged 18 years and above, sampled from nationally representative data provided by the China National Human Biomonitoring (CNHBM). Weighted multiple linear regression and restricted cubic spline (RCS) models were used to explore the associations between eight individual PFAS concentrations and total thyroxine (T4), total triiodothyronine (T3), and the T4/T3 ratio. Bayesian kernel machine regression (BKMR) and quantile-based g-computation (qgcomp) were employed to explore the joint and independent effects of PFASs on thyroid homeostasis. Both individual PFASs and PFAS mixtures exhibited a significant inverse association with serum T3 and T4 levels, and displayed a positive association with the T4/T3 ratio. Perfluoroundecanoic acid (PFUnDA) [-0.07 (95 % confidence interval (CI): -0.08, -0.05)] exhibited the largest change in T3 level. PFUnDA also exhibited a higher weight compared to other PFAS compounds in qgcomp models. Additionally, a critical exposure threshold for each PFAS was identified based on nonlinear dose-response associations; beyond these thresholds, the decreases in T3 and T4 levels plateaued. Specifically, for perfluoroheptane sulfonic acid (PFHpS) and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA), an initial decline in hormone levels was observed, followed by a slight increase when concentrations surpassed 0.7 ng/mL and 2.5 ng/mL, respectively. Sex-specific effects were more pronounced in females, and significant associations were observed predominantly in younger age groups. These insights contribute to our understanding of how PFAS compounds impact thyroid health and emphasize the need for further research and environmental management measures to address these complexities.
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Affiliation(s)
- Yanan Xing
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zheng Li
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jinghua Wang
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yingli Qu
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qiongpu Hu
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Saisai Ji
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiaochen Chang
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Feng Zhao
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yuebin Lv
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yitao Pan
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Xiaoming Shi
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China.
| | - Jiayin Dai
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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7
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Forner-Piquer I, Baig AH, Kortenkamp A. Disruption of the thyroid hormone system and patterns of altered thyroid hormones after gestational chemical exposures in rodents - a systematic review. Front Endocrinol (Lausanne) 2024; 14:1323284. [PMID: 38352246 PMCID: PMC10863050 DOI: 10.3389/fendo.2023.1323284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 11/30/2023] [Indexed: 02/16/2024] Open
Abstract
We present a comprehensive overview of changes in thyroxine (T4) and thyroid stimulating hormone (TSH) serum concentrations after pre-gestational, gestational and/or lactation exposures of rodents to various chemicals that affect the thyroid hormone system. We show that T4 and TSH changes consistent with the idealized view of the hypothalamic-pituitary-thyroid (HPT) feedback loop (T4 decrements accompanied by TSH increases) are observed with only a relatively small set of chemicals. Most substances affect concentrations of various thyroid hormones without increasing TSH. Studies of altered T4 concentrations after gestational exposures are limited to a relatively small set of chemicals in which pesticides, pharmaceuticals and industrial chemicals are under-represented. Our risk-of-bias analysis exposed deficits in T4/TSH analytics as a problem area. By relating patterns of T4 - TSH changes to mode-of-action (MOA) information, we found that chemicals capable of disrupting the HPT feedback frequently affected thyroid hormone synthesis, while substances that produced T4 serum decrements without accompanying TSH increases lacked this ability, but often induced liver enzyme systems responsible for the elimination of TH by glucuronidation. Importantly, a multitude of MOA leads to decrements of serum T4. The current EU approaches for identifying thyroid hormone system-disrupting chemicals, with their reliance on altered TH serum levels as indicators of a hormonal mode of action and thyroid histopathological changes as indicators of adversity, will miss chemicals that produce T4/T3 serum decreases without accompanying TSH increases. This is of concern as it may lead to a disregard for chemicals that produce developmental neurotoxicity by disrupting adequate T4/T3 supply to the brain, but without increasing TSH.
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Affiliation(s)
| | | | - Andreas Kortenkamp
- Centre for Pollution Research and Policy, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
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Volz SN, Poulsen R, Hansen M, Holbech H. Bisphenol A alters retinal morphology, visually guided behavior, and thyroid hormone levels in zebrafish larvae. CHEMOSPHERE 2024; 348:140776. [PMID: 38000552 DOI: 10.1016/j.chemosphere.2023.140776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/12/2023] [Accepted: 11/19/2023] [Indexed: 11/26/2023]
Abstract
Bisphenols are industrial chemicals that are produced in large quantities and have been detected in all parts of the environment as well as in a multitude of different organisms including humans and fish. Several bisphenols, such as bisphenol A (BPA) and bisphenol F, have been shown to disrupt endocrine systems thereby affecting development and reproduction. While numerous studies investigated the effect of bisphenols on estrogen signaling, their impact on the thyroid hormone system (THS), which is vital for neurodevelopment including sensory development, has been explored to a lesser extent. The present work selected BPA as a representative for structurally similar bisphenols and assessed its impact on the THS as well as sensory development and function in zebrafish. To this end, zebrafish were exposed to BPA until up to 8 days post fertilization (dpf) and thyroid hormone levels, eye morphology, and sensory-mediated behaviors were analyzed. Zebrafish larvae exposed to BPA showed altered retinal layering, decreased motility across varying light conditions, and a loss of responsiveness to red light. Furthermore, whole-body levels of the thyroid hormones thyroxine (T4) and 3,5-diiodothyronine (3,5-T2) were significantly decreased in 5 dpf zebrafish. Taken together, BPA disrupted THS homeostasis and compromised visual development and function, which is pivotal for the survival of fish larvae. This work underlines the necessity for ongoing research on BPA and its numerous substitutes, particularly concerning their effects on the THS and neurodevelopment, to ensure a high level of protection for the environment and human health.
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Affiliation(s)
- Sina N Volz
- Department of Biology, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.
| | - Rikke Poulsen
- Department of Environmental Science, University of Aarhus, Frederiksborgvej 399, 4000, Roskilde, Denmark.
| | - Martin Hansen
- Department of Environmental Science, University of Aarhus, Frederiksborgvej 399, 4000, Roskilde, Denmark.
| | - Henrik Holbech
- Department of Biology, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.
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9
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Lee J, Park JW, Kim HI, Park CB, Cho SH. Thyroid-gonadal hormonal interplay in zebrafish exposed to sodium perchlorate: Implications for reproductive health. CHEMOSPHERE 2024; 346:140662. [PMID: 37949182 DOI: 10.1016/j.chemosphere.2023.140662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/05/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
Perchlorate, a widespread environmental contaminant originating from various industrial applications, agricultural practices, and natural sources, poses potential risks to ecosystems and human health. While previous studies have highlighted its influence on the thyroid endocrine system and its impact on gonadal maturation, reproduction, and sex hormone synthesis, the specific interplay between thyroid and steroid hormones, in this context, remains largely unexplored. Therefore, this study was undertaken to investigate the adverse effects and underlying mechanisms triggered by exposure to sodium perchlorate (SP) on reproductive endocrine activity in zebrafish. For 21 d, the fish were exposed to test SP concentrations (0, 3, 30, 300 mg/L), which were determined based on the exposure concentrations that induced various toxic effects in the fish, considering naturally occurring concentrations. Exposure to SP, except at 3 mg/L in males, significantly decreased the production of thyroid hormone (TH) in both female and male zebrafish. Moreover, gonadal steroid levels were markedly reduced in both sexes. The expression of hepatic vitellogenin (VTG) mRNA in female zebrafish was significantly decreased, whereas aromatase activity in male zebrafish was significantly elevated in the SP exposure groups. The reduced levels of THs and gonadal steroid hormones were strongly correlated. Abnormal responses to SP exposure led to reduced reproductive success in the 300 mg/L SP exposure group. These findings indicate that prolonged and continuous exposure to a specific concentration of SP may lead to long-term reproductive problems in zebrafish, primarily through hormonal imbalances and suppression of hepatic VTG mRNA expression.
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Affiliation(s)
- Jangjae Lee
- Chemical Analysis Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea; Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | - June-Woo Park
- Environmental Exposure & Toxicology Research Center, Korea Institute of Toxicology (KIT), Jinju 52834, Republic of Korea
| | - Hugh I Kim
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | - Chang-Beom Park
- Environmental Exposure & Toxicology Research Center, Korea Institute of Toxicology (KIT), Jinju 52834, Republic of Korea.
| | - Sung-Hee Cho
- Chemical Analysis Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea.
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10
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Lan L, Wei H, Chen D, Pang L, Xu Y, Tang Q, Li J, Xu Q, Li H, Lu C, Wu W. Associations between maternal exposure to perfluoroalkylated substances (PFASs) and infant birth weight: a meta-analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:89805-89822. [PMID: 37458883 DOI: 10.1007/s11356-023-28458-0] [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: 12/25/2022] [Accepted: 06/23/2023] [Indexed: 08/11/2023]
Abstract
The objective of this study was to determine the associations between maternal exposure to PFASs and infant birth weight and to explore evidence for a possible dose-response relationship. Four databases including PubMed, Embase, Web of Science, and Medline before 20 September 2022 were systematically searched. A fixed-effect model was used to estimate the change in infant birth weight (g) associated with PFAS concentrations increasing by 10-fold. Dose-response meta-analyses were also conducted when possible. The study follows the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of 21 studies were included. Among these studies, 18 studies examined the associations between PFOA and birth weight, 17 studies reported PFOS, and 11 studies discussed PFHxS. Associations between PFHxS (ES = -5.67, 95% CI: -33.92 to 22.59, P = 0.694) were weaker than those for PFOA and PFOS (ES = -58.62, 95% CI: -85.23 to -32.01, P < 0.001 for PFOA; ES = -54.75, 95% CI: -84.48 to -25.02, P < 0.001 for PFOS). The association was significantly stronger in the high median PFOS concentration group (ES = -107.23, 95% CI: -171.07 to -43.39, P < 0.001) than the lower one (ES = -29.15, 95% CI: -63.60 to -5.30, P = 0.097; meta-regression, P = 0.045). Limited evidence of a dose-response relationship was found. This study showed negative associations between maternal exposure to PFASs and infant birth weight. Limited evidence of a dose-response relationship between exposure to PFOS and infant birth weight was found. Further studies are needed to find more evidence.
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Affiliation(s)
- Linchen Lan
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Hongcheng Wei
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Danrong Chen
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Liya Pang
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yifan Xu
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Qiuqin Tang
- Department of Obstetrics, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Jinhui Li
- Stanford University Medical Center, Stanford, CA, USA
| | - Qiaoqiao Xu
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Huijun Li
- Xinxiang Medical University, Xinxiang, 453003, Henan, China
| | - Chuncheng Lu
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Wei Wu
- State Key Laboratory of Reproductive Medicine, Wuxi Medical Center, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, China.
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
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11
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Martinez ME, Wu Z, Hernandez A. Paternal developmental thyrotoxicosis disrupts neonatal leptin leading to increased adiposity and altered physiology of the melanocortin system. Front Endocrinol (Lausanne) 2023; 14:1210414. [PMID: 37560296 PMCID: PMC10407661 DOI: 10.3389/fendo.2023.1210414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 07/10/2023] [Indexed: 08/11/2023] Open
Abstract
Background The genetic code does not fully explain individual variability and inheritance of susceptibility to endocrine conditions, suggesting the contribution of epigenetic factors acting across generations. Methods We used a mouse model of developmental thyrotoxicosis (Dio3-/- mouse) to analyze endocrine outcomes in the adult offspring of Dio3-/- males using standard methods for body composition, and baseline and fasting hormonal and gene expression determinations in serum and tissues of relevance to the control of energy balance. Results Compared to controls, adult females with an exposed father (EF females) exhibited higher body weight and fat mass, but not lean mass, a phenotype that was much milder in EF males. After fasting, both EF females and males exhibited a more pronounced decrease in body weight than controls. EF females also showed markedly elevated serum leptin, increased white adipose tissue mRNA expression of leptin and mesoderm-specific transcript but decreased expression of type 2 deiodinase. EF females exhibited decreased serum ghrelin, which showed more pronounced post-fasting changes in EF females than in control females. EF female hypothalami also revealed significant decreases in the expression of pro-opiomelanocortin, agouti-related peptide, neuropeptide Y and melanocortin receptor 4. These markers also showed larger changes in response to fasting in EF females than in control females. Adult EF females showed no abnormalities in serum thyroid hormones, but pituitary expression of thyrotropin-releasing hormone receptor 1 and thyroid gland expression of thyroid-stimulating hormone receptor, thyroid peroxidase and iodotyrosine deiodinase were increased at baseline and showed differential regulation after fasting, with no increase in Trhr1 expression and more pronounced reductions in Tshr, Tpo and Iyd. In EF males, these abnormalities were generally milder. In addition, postnatal day 14 (P14) serum leptin was markedly reduced in EF pups. Discussion A paternal excess of thyroid hormone during development modifies the endocrine programming and energy balance in the offspring in a sexually dimorphic manner, with baseline and dynamic range alterations in the leptin-melanocortin system and thyroid gland, and consequences for adiposity phenotypes. We conclude that thyroid hormone overexposure may have important implications for the non-genetic, inherited etiology of endocrine and metabolic pathologies.
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Affiliation(s)
- Maria Elena Martinez
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, United States
| | - Zhaofei Wu
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, United States
| | - Arturo Hernandez
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, United States
- Graduate School for Biomedical Sciences and Engineering, University of Maine, Orono, ME, United States
- Department of Medicine, Tufts University School of Medicine, Boston, MA, United States
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12
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Arts JHE, Faulhammer F, Schneider S, Salverda JGW. Investigations on learning and memory function in extended one-generation reproductive toxicity studies - when considered needed and based on what? Crit Rev Toxicol 2023; 53:372-384. [PMID: 37540214 DOI: 10.1080/10408444.2023.2236134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/29/2023] [Accepted: 07/07/2023] [Indexed: 08/05/2023]
Abstract
To justify investigations on learning and memory (L&M) function in extended one-generation reproductive toxicity studies (EOGRTS; Organization for Economic Co-operation and Development (OECD) test guideline (TG) 443) for registration under Registration, Evaluation, Authorization, and Restriction of Chemical (REACH), the European Chemicals Agency has referred to three publications based on which the Agency concluded that "perturbation of thyroid hormone signaling in offspring affects spatial cognitive abilities (learning and memory)" and "Therefore, it is necessary to conduct spatial learning and memory tests for F1 animals". In this paper, the inclusion of the requested L&M tests in an EOGRTS is challenged. In addition, next to the question on the validity of rodent models in general for testing thyroid hormone-dependent perturbations in brain development, the reliability of the publications specifically relied upon by the agency is questioned as these contain numerous fundamental errors in study methodology, design, and data reporting, provide contradicting results, lack crucial information to validate the results and exclude confounding factors, and finally show no causal relationship. Therefore, in our opinion, these publications cannot be used to substantiate, support, or conclude that decreases in blood thyroid (T4) hormone level on their own would result in impaired L&M in rats and are thus not adequate to use as fundament to ask for L&M testing as part of an EOGRTS.
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Affiliation(s)
- Josje H E Arts
- Nouryon Functional Chemicals B.V., Deventer, The Netherlands
| | - Frank Faulhammer
- GB Product Stewardship - Regulations, Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
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13
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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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14
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Ford J, Riutta C, Kosian PA, O'Shaughessy K, Gilbert M. Reducing uncertainties in quantitative adverse outcome pathways by analysis of thyroid hormone in the neonatal rat brain. Toxicol Sci 2023; 193:192-203. [PMID: 37099719 PMCID: PMC10732312 DOI: 10.1093/toxsci/kfad040] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
A number of xenobiotics interfere with thyroid hormone (TH) signaling. Although adequate supplies of TH are necessary for normal brain development, regulatory reliance on serum TH as proxies for brain TH insufficiency is fraught with significant uncertainties. A more direct causal linkage to neurodevelopmental toxicity induced by TH-system disrupting chemicals is to measure TH in the target organ of most concern, the brain. However, the phospholipid-rich matrix of brain tissue presents challenges for TH extraction and measurement. We report optimized analytical procedures to extract TH in brain tissue of rats with recoveries >80% and low detection limits for T3, rT3, and T4 (0.013, 0.033, and 0.028 ng/g, respectively). Recovery of TH is augmented by enhancing phospholipid separation from TH using an anion exchange column coupled with a stringent column wash. Quality control measures incorporating a matrix-matched calibration procedure revealed excellent recovery and consistency across a large number of samples. Application of optimized procedures revealed age-dependent increases in neonatal brain T4, T3, and rT3 on the day of birth (postnatal day, PN0), PN2, PN6, and PN14. No sex-dependent differences in brain TH were observed at these ages, and similar TH levels were evident in perfused versus non-perfused brains. Implementation of a robust and reliable method to quantify TH in the fetal and neonatal rat brain will aid in the characterization of the thyroid-dependent chemical interference on neurodevelopment. A brain- in addition to a serum-based metric will reduce uncertainties in assessment of hazard and risk on the developing brain posed by thyroid system-disrupting chemicals.
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Affiliation(s)
- Jermaine Ford
- Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Cal Riutta
- Oak Ridge Institute for Science Education, Oak Ridge, Tennessee 37830, USA
| | - Patricia A Kosian
- Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota 55804, USA
| | - Katherine O'Shaughessy
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Mary Gilbert
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
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15
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Chen L, Xie Y, Li M, Mortimer M, Li F, Guo LH. Toxicological Mechanisms of Emerging Per-/poly-fluoroalkyl Substances: Focusing on Transcriptional Activity and Gene Expression Disruption. Toxicology 2023:153566. [PMID: 37263573 DOI: 10.1016/j.tox.2023.153566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/27/2023] [Accepted: 05/29/2023] [Indexed: 06/03/2023]
Abstract
Environmental and human monitoring studies have witnessed increasing occurrence of emerging per-/poly-fluoroalkyl substances (ePFASs) worldwide. Three classes of ePFASs, namely chlorinated polyfluoroalkylether sulfonic acids, hexafluoropropylene oxide homologues and short-chain perfluoroalkyl acids attracted the most attention. It is, therefore, the goal of this review to systematically and critically analyse the toxicity and toxicological mechanisms of these ePFASs based on the papers published between 2017 and 2022. The review summarized the main findings from both in vivo and in vitro studies, covering the hepatotoxicity of ePFASs and their interference with the endocrine system, including reproductive, developmental and thyroid toxicity. It also summarized the changes in gene expression in the hypothalamic-pituitary-thyroid axis and hypothalamic-pituitary-gonad axis of the model organisms after ePFASs exposure. The changes in gene expression in vitro and in vivo provide a clearer understanding of the toxicological mechanisms of ePFASs interference on hormonal levels (i.e., estradiol, testosterone, and thyroid hormones), developmental disturbance (e.g., swim bladder dysfunction) and lipid metabolism disruption (e.g., lipid droplet accumulation and hepatomegaly). In the end, future research directions on the toxicological mechanisms of ePFASs are suggested.
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Affiliation(s)
- Lu Chen
- College of Life Sciences, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang310018, China; Institute of Environmental and Health Sciences, China Jiliang University, 168 Xueyuan Street, Hangzhou, Zhejiang310018, China.
| | - Yue Xie
- College of Life Sciences, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang310018, China; Institute of Environmental and Health Sciences, China Jiliang University, 168 Xueyuan Street, Hangzhou, Zhejiang310018, China.
| | - Minjie Li
- College of Quality and Safety Engineering, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang310018, China.
| | - Monika Mortimer
- Institute of Environmental and Health Sciences, China Jiliang University, 168 Xueyuan Street, Hangzhou, Zhejiang310018, China; College of Quality and Safety Engineering, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang310018, China.
| | - Fangfang Li
- Institute of Environmental and Health Sciences, China Jiliang University, 168 Xueyuan Street, Hangzhou, Zhejiang310018, China; College of Quality and Safety Engineering, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang310018, China.
| | - Liang-Hong Guo
- Institute of Environmental and Health Sciences, China Jiliang University, 168 Xueyuan Street, Hangzhou, Zhejiang310018, China; College of Quality and Safety Engineering, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang310018, China.
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16
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Lu T, Mortimer M, Li F, Li Z, Chen L, Li M, Guo LH. Putative adverse outcome pathways of the male reproductive toxicity derived from toxicological studies of perfluoroalkyl acids. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 873:162439. [PMID: 36848992 DOI: 10.1016/j.scitotenv.2023.162439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/15/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Adverse outcome pathway (AOP) as a conceptual framework is a powerful tool in the field of toxicology to connect seemingly discrete events at different levels of biological organizations into an organized pathway from molecular interactions to whole organism toxicity. Based on numerous toxicological studies, eight AOPs for reproductive toxicity have been endorsed by the Organization for Economic Co-operation and Development (OECD) Task Force on Hazard Assessment. We have conducted a literature survey on the mechanistic studies on male reproductive toxicity of perfluoroalkyl acids (PFAAs), a class of global environmental contaminants with high persistence, bioaccumulation and toxicity. Using the AOP development strategy, five new AOPs for male reproductive toxicity were proposed here, namely (1) changes in membrane permeability leading to reduced sperm motility, (2) disruption of mitochondrial function leading to sperm apoptosis, (3) decreased gonadotropin-releasing hormone (GnRH) expression in hypothalamus leading to reduced testosterone production in male rats, (4) activation of the p38 signaling pathway leading to disruption of BTB in mice, (5) inhibition of p-FAK-Tyr407 activity leading to the destruction of BTB. The molecular initiating events in the proposed AOPs are different from those in the endorsed AOPs, which are either receptor activation or enzyme inhibition. Although some of the AOPs are still incomplete, they can serve as a building block upon which full AOPs can be developed and applied to not only PFAAs but also other chemical toxicants with male reproductive toxicity.
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Affiliation(s)
- Tingyu Lu
- College of Life Science, China Jiliang University, Hangzhou, Zhejiang 310018, China; Institute of Environmental and Health Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
| | - Monika Mortimer
- Institute of Environmental and Health Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China; College of Quality and Safety Engineering, China Jiliang University, Hangzhou, Zhejiang 310018, China.
| | - Fangfang Li
- Institute of Environmental and Health Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China; College of Quality and Safety Engineering, China Jiliang University, Hangzhou, Zhejiang 310018, China.
| | - Zhi Li
- College of Life Science, China Jiliang University, Hangzhou, Zhejiang 310018, China; Institute of Environmental and Health Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
| | - Lu Chen
- College of Life Science, China Jiliang University, Hangzhou, Zhejiang 310018, China; Institute of Environmental and Health Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
| | - Minjie Li
- College of Quality and Safety Engineering, China Jiliang University, Hangzhou, Zhejiang 310018, China.
| | - Liang-Hong Guo
- Institute of Environmental and Health Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China; College of Quality and Safety Engineering, China Jiliang University, Hangzhou, Zhejiang 310018, China.
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17
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Pasquier E, Viguié C, Fini JB, Mhaouty-Kodja S, Michel-Caillet C. Limits of the regulatory evaluation of resorcinol as a thyroid disruptor: When limited experimental data challenge established effects in humans. ENVIRONMENTAL RESEARCH 2023; 222:115330. [PMID: 36693459 DOI: 10.1016/j.envres.2023.115330] [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: 11/21/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
Severe hypothyroidism has been reported in humans during resorcinol therapeutic use. However, available data highlight differences in the severity of resorcinol-induced thyroid effects between humans and rodents, leading to a debate on the relevance of human data for its classification as a thyroid disruptor. The aim of this review is to illustrate some of the limitations of the evaluation framework for thyroid disrupters using resorcinol as a case study of a chemical with clear thyroid-disrupting properties in humans that could not have been identified solely from regulatory studies on animals. The reliability of human data has been called into question due to the specific exposure patterns in humans and the paucity of robust toxicokinetic data. In humans, therapeutic use of resorcinol induces severe hypothyroidism, but in rodents, thyroid disruption is limited to decreased thyroxine concentrations and histological changes in the thyroid. The adverse effects of thyroid disruption, such as impaired neurodevelopment, have not been sufficiently investigated, and experimental neurobehavioral data for resorcinol remain scarce and inconclusive. Although regulatory toxicological evaluations have not included in-depth investigations of thyroid regulation and related adverse effects, they have been used to challenge the relevance of human data. Resorcinol is an emblematic example of how the framework for regulatory evaluations of thyroid disruptors relies almost exclusively on animal studies which may not be suitable for assessing thyroid disruption. This review highlights the need to revise regulatory guidelines and to adopt strategies based on up-to-date, scientifically sound approaches to identify thyroid disruptors. The limits of the current regulatory framework for identifying thyroid disruptors can lead to opposing positions between regulatory bodies. The French Agency for Food, Environmental and Occupational Health & Safety (ANSES)'proposal to identify resorcinol as a "substance of very high concern" due to its ED properties has not been adopted by the European instances.
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Affiliation(s)
| | - Catherine Viguié
- Toxalim (Research Centre in Food Toxicology) UMR 1331, INRAE, ENVT, INP-Purpan, UPS 180 Chemin de Tournefeuille, BP 93173 31027, Toulouse, France.
| | | | - Sakina Mhaouty-Kodja
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine - Institut de Biologie Paris Seine, Paris, France
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18
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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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Wang H, Ren T, Zhang N, Xia W, Xiang M, Ran J, Zhang J. Poly- and perfluoroalkyl substances exposure during pregnancy and postpartum depression: Evidence from the Shanghai birth cohort. CHEMOSPHERE 2023; 318:137941. [PMID: 36702402 DOI: 10.1016/j.chemosphere.2023.137941] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/19/2023] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Exposure to poly-and perfluoroalkyl substances (PFASs) has been linked to psychiatric disorders in the general population. Because women in the postpartum period are susceptible to mental disorders, we aimed to investigate the association between exposure to PFASs during pregnancy and postpartum depression (PPD). METHODS Our study consisted of 2741 pregnant women who were enrolled in the Shanghai Birth Cohort during the early pregnancy and gave birth to a singleton live birth between 2013 and 2016. A total of 10 PFASs were measured in maternal plasma collected in early gestation by high-performance liquid chromatography/tandem mass spectrometry. PPD was assessed using the Edinburgh Postnatal Depression Scale (EPDS) at 42 days after the child birth. We used multivariable logistic regression to estimate the association between exposure to PFASs and PPD, adjusted for potential confounders. Negative binomial regression was used to assess the association between PFASs exposure during pregnancy and EPDS subscales including anhedonia, anxiety, and depression. A quantile-based g-computation approach was used to evaluate the joint and independent effects of PFASs on PPD. RESULTS Around 11.7% of the mothers had probable PPD (EPDS cut-off ≥10). Overall, exposure to PFASs in early pregnancy was not associated with PPD or EPDS subscales. Quantile g-computation method also showed that increasing PFASs mixture by one quartile was not associated with PPD (odds ratio, 1.08; 95% confidence interval: 0.91, 1.29). CONCLUSION Our findings indicate that exposure to PFASs during pregnancy was not associated with PPD at 6 weeks postpartum.
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Affiliation(s)
- Hui Wang
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Tai Ren
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Na Zhang
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weiping Xia
- Department of Medical Psychology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, China
| | - Mi Xiang
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinjun Ran
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Zhang
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China; School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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20
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Cook EK, Olivares CI, Antell EH, Yi S, Nickerson A, Choi YJ, Higgins CP, Sedlak DL, Alvarez-Cohen L. Biological and Chemical Transformation of the Six-Carbon Polyfluoroalkyl Substance N-Dimethyl Ammonio Propyl Perfluorohexane Sulfonamide (AmPr-FHxSA). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15478-15488. [PMID: 36257682 DOI: 10.1021/acs.est.2c00261] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Sites impacted by aqueous film-forming foam (AFFF) contain co-contaminants that can stimulate biotransformation of polyfluoroalkyl substances. Here, we compare how microbial enrichments from AFFF-impacted soil amended with diethyl glycol monobutyl ether (found in AFFF), aromatic hydrocarbons (present in co-released fuels), acetate, and methane (substrates used or formed during bioremediation) impact the aerobic biotransformation of an AFFF-derived six-carbon electrochemical fluorination (ECF) precursor N-dimethyl ammonio propyl perfluorohexane sulfonamide (AmPr-FHxSA). We found that methane- and acetate-oxidizing cultures resulted in the highest yields of identifiable products (38 and 30%, respectively), including perfluorohexane sulfonamide (FHxSA) and perfluorohexane sulfonic acid (PFHxS). Using these data, we propose and detail a transformation pathway. Additionally, we examined chemical oxidation products of AmPr-FHxSA and FHxSA to provide insights on remediation strategies for AmPr-FHxSA. We demonstrate mineralization of these compounds using the sulfate radical and test their transformation during the total oxidizable precursor (TOP) assay. While perfluorohexanoic acid accounted for over 95% of the products formed, we demonstrate here for the first time two ECF-based precursors, AmPr-FHxSA and FHxSA, that produce PFHxS during the TOP assay. These findings have implications for monitoring poly- and perfluoroalkyl substances during site remediation and application of the TOP assay at sites impacted by ECF-based precursors.
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Affiliation(s)
- Emily K Cook
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Christopher I Olivares
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
- Department of Civil and Environmental Engineering, University of California, Irvine, California 92697, United States
| | - Edmund H Antell
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Shan Yi
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
- Department of Chemical and Materials Engineering, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Anastasia Nickerson
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Youn Jeong Choi
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - David L Sedlak
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
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21
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Gundacker C, Audouze K, Widhalm R, Granitzer S, Forsthuber M, Jornod F, Wielsøe M, Long M, Halldórsson TI, Uhl M, Bonefeld-Jørgensen EC. Reduced Birth Weight and Exposure to Per- and Polyfluoroalkyl Substances: A Review of Possible Underlying Mechanisms Using the AOP-HelpFinder. TOXICS 2022; 10:toxics10110684. [PMID: 36422892 PMCID: PMC9699222 DOI: 10.3390/toxics10110684] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 05/14/2023]
Abstract
Prenatal exposure to per- and polyfluorinated substances (PFAS) may impair fetal growth. Our knowledge of the underlying mechanisms is incomplete. We used the Adverse Outcome Pathway (AOP)-helpFinder tool to search PubMed for studies published until March 2021 that examined PFAS exposure in relation to birth weight, oxidative stress, hormones/hormone receptors, or growth signaling pathways. Of these 1880 articles, 106 experimental studies remained after abstract screening. One clear finding is that PFAS are associated with oxidative stress in in vivo animal studies and in vitro studies. It appears that PFAS-induced reactive-oxygen species (ROS) generation triggers increased peroxisome proliferator-activated receptor (PPAR)γ expression and activation of growth signaling pathways, leading to hyperdifferentiation of pre-adipocytes. Fewer proliferating pre-adipocytes result in lower adipose tissue weight and in this way may reduce birth weight. PFAS may also impair fetal growth through endocrine effects. Estrogenic effects have been noted in in vivo and in vitro studies. Overall, data suggest thyroid-damaging effects of PFAS affecting thyroid hormones, thyroid hormone gene expression, and histology that are associated in animal studies with decreased body and organ weight. The effects of PFAS on the complex relationships between oxidative stress, endocrine system function, adipogenesis, and fetal growth should be further explored.
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Affiliation(s)
- Claudia Gundacker
- Institute of Medical Genetics, Medical University of Vienna, 1090 Vienna, Austria
- Correspondence: ; Tel.: +43-1-40160-56503
| | - Karine Audouze
- Unit T3S, Université Paris Cité, Inserm U1124, 75006 Paris, France
| | - Raimund Widhalm
- Institute of Medical Genetics, Medical University of Vienna, 1090 Vienna, Austria
| | - Sebastian Granitzer
- Institute of Medical Genetics, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin Forsthuber
- Institute of Medical Genetics, Medical University of Vienna, 1090 Vienna, Austria
| | - Florence Jornod
- Unit T3S, Université Paris Cité, Inserm U1124, 75006 Paris, France
| | - Maria Wielsøe
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark
| | - Manhai Long
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark
| | - Thórhallur Ingi Halldórsson
- Faculty of Food Science and Nutrition, University of Iceland, 102 Reykjavík, Iceland
- Department of Epidemiology Research, Statens Serum Institut, 2300 Copenhagen, Denmark
| | - Maria Uhl
- Environment Agency Austria, 1090 Vienna, Austria
| | - Eva Cecilie Bonefeld-Jørgensen
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark
- Greenland Center for Health Research, Greenland University, Nuuk 3905, Greenland
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22
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Derakhshan A, Kortenkamp A, Shu H, Broeren MAC, Lindh CH, Peeters RP, Bornehag CG, Demeneix B, Korevaar TIM. Association of per- and polyfluoroalkyl substances with thyroid homeostasis during pregnancy in the SELMA study. ENVIRONMENT INTERNATIONAL 2022; 167:107420. [PMID: 35870378 DOI: 10.1016/j.envint.2022.107420] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVES To investigate the association of exposure to per- and polyfluoroalkyl substances (PFAS) during early pregnancy with markers of the maternal thyroid system. METHODS Serum concentrations of seven PFAS as well as thyroid stimulating hormone (TSH), free and total thyroxine (FT4 and TT4), free and total triiodothyronine (FT3 and TT3) were measured in pregnant women in early pregnancy in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study. Outcomes were concentrations of TSH and thyroid hormones, FT4/FT3 or TT4/TT3 ratios, TSH/FT4 ratio as a marker of the negative feedback loop, TT4/FT4 or TT3/FT3 ratios as markers of the binding of thyroid hormones to binding proteins. RESULTS The study population comprised 2,008 women with median (95% range) gestational age of 10 (6-14) weeks. There was no association between PFAS and TSH. Higher PFNA, PFDA, PFHpA and PFOA levels were associated with a higher FT4 (largest effect estimate for PFDA: β [95% CI]: 0.27 [0.10 to 0.45], P = 0.002). Higher PFUnDA levels, but no other PFAS, were associated with a lower FT3 (β [95% CI]: -0.05 [-0.09 to -0.01], P = 0.005). Higher PFUnDA levels were associated with lower TT4 (β [95% CI]: -1.58 [-3.07 to -0.09]) and there was an inverted U-shaped association of PFOS with TT4 (P = 0.03). Higher PFDA, PFUnDA, PFHpA levels were associated with a lower TT3. Overall, higher PFAS concentrations were associated with a higher FT4/FT3 ratio and a higher TT4/TT3 ratio. There was no association of PFAS with the TSH/FT4 ratio. Higher concentrations of several PFAS were associated with lower TT4/FT4 and TT3/FT3 ratios. CONCLUSIONS These findings translate results from experimental studies suggesting that exposure to PFAS may interfere with the thyroid system during pregnancy. Further experimental studies should take into account human evidence to better understand the potential underlying mechanisms of thyroid disruption by PFAS exposure.
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Affiliation(s)
- Arash Derakhshan
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, The Netherlands; Department of internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, the Netherlands
| | - Andreas Kortenkamp
- Division of Environmental Sciences, College of Health, Medicine and Life Sciences, Brunel University, London, Uxbridge, UK
| | - Huan Shu
- Department of Public Health, Karlstad University, Sweden
| | - Maarten A C Broeren
- Laboratory of Clinical Chemistry and Haematology, Máxima Medical Centre, Veldhoven, De Run, 4600, The Netherlands
| | - Christian H Lindh
- Division of Occupational and Environmental Medicine, Lund University, Lund, 22363 Lund, Sweden
| | - Robin P Peeters
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, The Netherlands; Department of internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, the Netherlands
| | - Carl-Gustaf Bornehag
- Department of Public Health, Karlstad University, Sweden; Icahn School of Medicine at Mount Sinai, New York City, NY, USA
| | - Barbara Demeneix
- Laboratoire d'Evolution des Régulations Endocriniennes, CNRS/Muséum National d'Histoire Naturelle, 57 Rue Cuvier, 75005 Paris, France
| | - Tim I M Korevaar
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, The Netherlands; Department of internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, the Netherlands.
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23
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Marty MS, Sauer UG, Charlton A, Ghaffari R, Guignard D, Hallmark N, Hannas BR, Jacobi S, Marxfeld HA, Melching-Kollmuss S, Sheets LP, Urbisch D, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny-part III: how is substance-mediated thyroid hormone imbalance in pregnant/lactating rats or their progeny related to neurodevelopmental effects? Crit Rev Toxicol 2022; 52:546-617. [PMID: 36519295 DOI: 10.1080/10408444.2022.2130166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review investigated which patterns of thyroid- and brain-related effects are seen in rats upon gestational/lactational exposure to 14 substances causing thyroid hormone imbalance by four different modes-of-action (inhibition of thyroid peroxidase, sodium-iodide symporter and deiodinase activities, enhancement of thyroid hormone clearance) or to dietary iodine deficiency. Brain-related parameters included motor activity, cognitive function, acoustic startle response, hearing function, periventricular heterotopia, electrophysiology and brain gene expression. Specific modes-of-action were not related to specific patterns of brain-related effects. Based upon the rat data reviewed, maternal serum thyroid hormone levels do not show a causal relationship with statistically significant neurodevelopmental effects. Offspring serum thyroxine together with offspring serum triiodothyronine and thyroid stimulating hormone appear relevant to predict the likelihood for neurodevelopmental effects. Based upon the collated database, thresholds of ≥60%/≥50% offspring serum thyroxine reduction and ≥20% and statistically significant offspring serum triiodothyronine reduction indicate an increased likelihood for statistically significant neurodevelopmental effects; accuracies: 83% and 67% when excluding electrophysiology (and gene expression). Measurements of brain thyroid hormone levels are likely relevant, too. The extent of substance-mediated thyroid hormone imbalance appears more important than substance mode-of-action to predict neurodevelopmental impairment in rats. Pertinent research needs were identified, e.g. to determine whether the phenomenological offspring thyroid hormone thresholds are relevant for regulatory toxicity testing. The insight from this review shall be used to suggest a tiered testing strategy to determine whether gestational/lactational substance exposure may elicit thyroid hormone imbalance and potentially also neurodevelopmental effects.
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Affiliation(s)
| | - Ursula G Sauer
- Scientific Consultancy-Animal Welfare, Neubiberg, Germany
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24
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Ramhøj L, Svingen T, Mandrup K, Hass U, Lund SP, Vinggaard AM, Hougaard KS, Axelstad M. Developmental exposure to the brominated flame retardant DE-71 reduces serum thyroid hormones in rats without hypothalamic-pituitary-thyroid axis activation or neurobehavioral changes in offspring. PLoS One 2022; 17:e0271614. [PMID: 35853081 PMCID: PMC9295973 DOI: 10.1371/journal.pone.0271614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 07/01/2022] [Indexed: 11/19/2022] Open
Abstract
Polybrominated diphenyl ethers (PBDEs) are legacy flame retardants for which human exposure remains ubiquitous. This is of concern since these chemicals can perturb development and cause adverse health effects. For instance, DE-71, a technical mixture of PBDEs, can induce liver toxicity as well as reproductive and developmental toxicity. DE-71 can also disrupt the thyroid hormone (TH) system which may induce developmental neurotoxicity indirectly. However, in developmental toxicity studies, it remains unclear how DE-71 exposure affects the offspring’s thyroid hormone system and if this dose-dependently relates to neurodevelopmental effects. To address this, we performed a rat toxicity study by exposing pregnant dams to DE-71 at 0, 40 or 60 mg/kg/day during perinatal development from gestational day 7 to postnatal day 16. We assessed the TH system in both dams and their offspring, as well as potential hearing and neurodevelopmental effects in prepubertal and adult offspring. DE-71 significantly reduced serum T4 and T3 levels in both dams and offspring without a concomitant upregulation of TSH, thus inducing a hypothyroxinemia-like effect. No discernible effects were observed on the offspring’s brain function when assessed in motor activity boxes and in the Morris water maze, or on offspring hearing function. Our results, together with a thorough review of the literature, suggest that DE-71 does not elicit a clear dose-dependent relationship between low serum thyroxine (T4) and effects on the rat brain in standard behavioral assays. However, low serum TH levels are in themselves believed to be detrimental to human brain development, thus we propose that we lack assays to identify developmental neurotoxicity caused by chemicals disrupting the TH system through various mechanisms.
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Affiliation(s)
- Louise Ramhøj
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
- * E-mail:
| | - Terje Svingen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Karen Mandrup
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ulla Hass
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Søren Peter Lund
- National Research Centre for the Working Environment, Copenhagen, Denmark
| | | | - Karin Sørig Hougaard
- National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Marta Axelstad
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
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25
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Davidsen N, Ramhøj L, Lykkebo CA, Kugathas I, Poulsen R, Rosenmai AK, Evrard B, Darde TA, Axelstad M, Bahl MI, Hansen M, Chalmel F, Licht TR, Svingen T. PFOS-induced thyroid hormone system disrupted rats display organ-specific changes in their transcriptomes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 305:119340. [PMID: 35460815 DOI: 10.1016/j.envpol.2022.119340] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/14/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Perfluorooctanesulfonic acid (PFOS) is a persistent anthropogenic chemical that can affect the thyroid hormone system in humans and animals. In adults, thyroid hormones (THs) are regulated by the hypothalamic-pituitary-thyroid (HPT) axis, but also by organs such as the liver and potentially the gut microbiota. PFOS and other xenobiotics can therefore disrupt the TH system at various locations and through different mechanisms. To start addressing this, we exposed adult male rats to 3 mg PFOS/kg/day for 7 days and analysed effects on multiple organs and pathways simultaneously by transcriptomics. This included four primary organs involved in TH regulation, namely hypothalamus, pituitary, thyroid, and liver. To investigate a potential role of the gut microbiota in thyroid hormone regulation, two additional groups of animals were dosed with the antibiotic vancomycin (8 mg/kg/day), either with or without PFOS. PFOS exposure decreased thyroxine (T4) and triiodothyronine (T3) without affecting thyroid stimulating hormone (TSH), resembling a state of hypothyroxinemia. PFOS exposure resulted in 50 differentially expressed genes (DEGs) in the hypothalamus, 68 DEGs in the pituitary, 71 DEGs in the thyroid, and 181 DEGs in the liver. A concomitant compromised gut microbiota did not significantly change effects of PFOS exposure. Organ-specific DEGs did not align with TH regulating genes; however, genes associated with vesicle transport and neuronal signaling were affected in the hypothalamus, and phase I and phase II metabolism in the liver. This suggests that a decrease in systemic TH levels may activate the expression of factors altering trafficking, metabolism and excretion of TH. At the transcriptional level, little evidence suggests that the pituitary or thyroid gland is involved in PFOS-induced TH system disruption.
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Affiliation(s)
- Nichlas Davidsen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Louise Ramhøj
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Claus Asger Lykkebo
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Indusha Kugathas
- Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail), UMR_S 1085, F-35000, Rennes, France
| | - Rikke Poulsen
- Department of Environmental Science, Aarhus University, Roskilde, DK-4000, Denmark
| | | | - Bertrand Evrard
- Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail), UMR_S 1085, F-35000, Rennes, France
| | | | - Marta Axelstad
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Martin Iain Bahl
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Martin Hansen
- Department of Environmental Science, Aarhus University, Roskilde, DK-4000, Denmark
| | - Frederic Chalmel
- Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail), UMR_S 1085, F-35000, Rennes, France
| | - Tine Rask Licht
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Terje Svingen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
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26
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Vancamp P, Le Blay K, Butruille L, Sébillot A, Boelen A, Demeneix BA, Remaud S. Developmental thyroid disruption permanently affects the neuroglial output in the murine subventricular zone. Stem Cell Reports 2022; 17:459-474. [PMID: 35120623 PMCID: PMC9039754 DOI: 10.1016/j.stemcr.2022.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 01/04/2022] [Accepted: 01/04/2022] [Indexed: 12/27/2022] Open
Abstract
Neural stem cells (NSCs) in the adult brain are a source of neural cells for brain injury repair. We investigated whether their capacity to generate new neurons and glia is determined by thyroid hormone (TH) during development because serum levels peak during postnatal reorganization of the main NSC niche, the subventricular zone (SVZ). Re-analysis of mouse transcriptome data revealed increased expression of TH transporters and deiodinases in postnatal SVZ NSCs, promoting local TH action, concomitant with a burst in neurogenesis. Inducing developmental hypothyroidism reduced NSC proliferation, disrupted expression of genes implicated in NSC determination and TH signaling, and altered the neuron/glia output in newborns. Three-month-old adult mice recovering from developmental hypothyroidism had fewer olfactory interneurons and underperformed on short-memory odor tests, dependent on SVZ neurogenesis. Our data provide readouts permitting comparison with adverse long-term events following thyroid disruptor exposure and ideas regarding the etiology of prevalent neurodegenerative diseases in industrialized countries. Thyroid hormone peak associates with a neurogenic wave in the postnatal murine SVZ Single-cell RNA-seq data show increased TH action in SVZ progenitors at that stage Developmental hypothyroidism disrupts neuroglial commitment and associated genes Transient developmental TH depletion impairs adult neurogliogenesis and olfaction
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Affiliation(s)
- Pieter Vancamp
- Laboratory Molecular Physiology and Adaptation, CNRS UMR 7221, Department Adaptations of Life, Muséum National d'Histoire Naturelle, 7 Rue Cuvier, 75005 Paris, France
| | - Karine Le Blay
- Laboratory Molecular Physiology and Adaptation, CNRS UMR 7221, Department Adaptations of Life, Muséum National d'Histoire Naturelle, 7 Rue Cuvier, 75005 Paris, France
| | - Lucile Butruille
- Laboratory Molecular Physiology and Adaptation, CNRS UMR 7221, Department Adaptations of Life, Muséum National d'Histoire Naturelle, 7 Rue Cuvier, 75005 Paris, France
| | - Anthony Sébillot
- Laboratory Molecular Physiology and Adaptation, CNRS UMR 7221, Department Adaptations of Life, Muséum National d'Histoire Naturelle, 7 Rue Cuvier, 75005 Paris, France
| | - Anita Boelen
- Endocrine Laboratory, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, 1105 Amsterdam, the Netherlands
| | - Barbara A Demeneix
- Laboratory Molecular Physiology and Adaptation, CNRS UMR 7221, Department Adaptations of Life, Muséum National d'Histoire Naturelle, 7 Rue Cuvier, 75005 Paris, France
| | - Sylvie Remaud
- Laboratory Molecular Physiology and Adaptation, CNRS UMR 7221, Department Adaptations of Life, Muséum National d'Histoire Naturelle, 7 Rue Cuvier, 75005 Paris, France.
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27
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PFAS Molecules: A Major Concern for the Human Health and the Environment. TOXICS 2022; 10:toxics10020044. [PMID: 35202231 PMCID: PMC8878656 DOI: 10.3390/toxics10020044] [Citation(s) in RCA: 75] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 01/09/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of over 4700 heterogeneous compounds with amphipathic properties and exceptional stability to chemical and thermal degradation. The unique properties of PFAS compounds has been exploited for almost 60 years and has largely contributed to their wide applicability over a vast range of industrial, professional and non-professional uses. However, increasing evidence indicate that these compounds represent also a serious concern for both wildlife and human health as a result of their ubiquitous distribution, their extreme persistence and their bioaccumulative potential. In light of the adverse effects that have been already documented in biota and human populations or that might occur in absence of prompt interventions, the competent authorities in matter of health and environment protection, the industries as well as scientists are cooperating to identify the most appropriate regulatory measures, substitution plans and remediation technologies to mitigate PFAS impacts. In this review, starting from PFAS chemistry, uses and environmental fate, we summarize the current knowledge on PFAS occurrence in different environmental media and their effects on living organisms, with a particular emphasis on humans. Also, we describe present and provisional legislative measures in the European Union framework strategy to regulate PFAS manufacture, import and use as well as some of the most promising treatment technologies designed to remediate PFAS contamination in different environmental compartments.
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28
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Ramhøj L, Svingen T, Frädrich C, Rijntjes E, Wirth EK, Pedersen K, Köhrle J, Axelstad M. Perinatal exposure to the thyroperoxidase inhibitors methimazole and amitrole perturbs thyroid hormone system signaling and alters motor activity in rat offspring. Toxicol Lett 2021; 354:44-55. [PMID: 34757178 DOI: 10.1016/j.toxlet.2021.10.010] [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: 07/21/2021] [Revised: 10/15/2021] [Accepted: 10/26/2021] [Indexed: 01/12/2023]
Abstract
Disruption of the thyroid hormone system during development can impair brain development and cause irreversible damage. Some thyroid hormone system disruptors act by inhibiting the thyroperoxidase (TPO) enzyme, which is key to thyroid hormone synthesis. For the potent TPO-inhibiting drug propylthiouracil (PTU) this has been shown to result in thyroid hormone system disruption and altered brain development in animal studies. However, an outstanding question is which chemicals beside PTU can cause similar effects on brain development and to what degree thyroid hormone insufficiency must be induced to be able to measure adverse effects in rats and their offspring. To start answering these questions, we performed a perinatal exposure study in pregnant rats with two TPO-inhibitors: the drug methimazole (MMI) and the triazole herbicide amitrole. The study involved maternal exposure from gestational day 7 through to postnatal day 22, to MMI (8 and 16 mg/kg body weight/day) or amitrole (25 and 50 mg/kg body weight/day). Both MMI and amitrole reduced serum T4 concentrations in a dose-dependent manner in dams and offspring, with a strong activation of the hypothalamic-pituitary-thyroid axis. This reduction in serum T4 led to decreased thyroid hormone-mediated gene expression in the offspring's brains and caused adverse effects on brain function, seen as hyperactivity and decreased habituation in preweaning pups. These dose-dependent effects induced by MMI and amitrole are largely the same as those observed with PTU. This demonstrates that potent TPO-inhibitors can induce effects on brain development in rats and that these effects are driven by T4 deficiency. This knowledge will aid the identification of TPO-inhibiting thyroid hormone system disruptors in a regulatory context and can serve as a starting point in search of more sensitive markers of developmental thyroid hormone system disruption.
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Affiliation(s)
- Louise Ramhøj
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Terje Svingen
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Caroline Frädrich
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, 10115, Berlin, Germany
| | - Eddy Rijntjes
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, 10115, Berlin, Germany
| | - Eva K Wirth
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Department of Endocrinology and Metabolism and Charité Center for Cardiovascular Research, 10115, Berlin, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Germany
| | - Katrine Pedersen
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Josef Köhrle
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, 10115, Berlin, Germany
| | - Marta Axelstad
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
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Yin X, Di T, Cao X, Liu Z, Xie J, Zhang S. Chronic exposure to perfluorohexane sulfonate leads to a reproduction deficit by suppressing hypothalamic kisspeptin expression in mice. J Ovarian Res 2021; 14:141. [PMID: 34706750 PMCID: PMC8555149 DOI: 10.1186/s13048-021-00903-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 10/13/2021] [Indexed: 01/09/2023] Open
Abstract
Background Perfluorohexane sulfonate (PFHxS) is a six-carbon perfluoroalkyl sulfonic acid found as an environmental contaminant. This study aims to investigate the effects of PFHxS exposure on female reproduction and the underlying mechanism in mice. Methods Eight-week-old ICR mice were divided randomly into four groups administered corn oil (vehicle) and PFHxS at doses of 0.5, 5, and 50 mg/kg/day for 42 days by intragastric administration. Body weight, ovarian weight, estrous cycle, follicle counts, and serum sex hormone levels were evaluated. The expression of kisspeptin and gonadotropin releasing hormone (GnRH) in the hypothalamus was also detected. Results Compared to vehicle exposure, 5 mg/kg/day PFHxS treatment prolonged the estrous cycle, especially the duration of diestrus, after 42 days of treatment. The numbers of secondary follicles, antral follicles and corpus lutea were significantly reduced in the PFHxS-treated mice. Moreover, compared with the control mice, the PFHxS-treated mice showed decreases in the serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estrogen (E2), and reduced GnRH mRNA levels, along with the lack of an LH surge. Furthermore, the PFHxS-treated mice had lower levels of kisspeptin immunoreactivity and kiss-1 mRNA in the arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV) than the control mice. After intraventricular administration of kisspeptin-10, the numbers of secondary follicles, antral follicles and corpus lutea recovered, along with the levels of GnRH mRNA, FSH, and LH in the mice treated with 5 mg/kg/day PFHxS. Conclusion These results indicate that chronic exposure of mice to 5 mg/kg/day PFHxS affects reproductive functions by inhibiting kisspeptin expression in the ARC and AVPV regions, leading to deficits in follicular development and ovulation. Supplementary Information The online version contains supplementary material available at 10.1186/s13048-021-00903-z.
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Affiliation(s)
- Xiaorui Yin
- Department of Obstetrics and Gynecology, Nanjing First Hospital, Nanjing Medical University, Changle Road 68, Nanjing, 210006, China
| | - Tingting Di
- Department of Pharmacology, Institute of Translational Medicine, School of Medicine, Yangzhou University, Yangzhou, 225001, China
| | - Xinyuan Cao
- Experimental Teaching Center of Basic Medicine, Nanjing Medical University, Nanjing, 210006, China
| | - Zhengnan Liu
- Department of Obstetrics and Gynecology, Nanjing First Hospital, Nanjing Medical University, Changle Road 68, Nanjing, 210006, China
| | - Jingyan Xie
- Department of Obstetrics and Gynecology, Nanjing First Hospital, Nanjing Medical University, Changle Road 68, Nanjing, 210006, China.
| | - Suyun Zhang
- Department of Obstetrics and Gynecology, Nanjing First Hospital, Nanjing Medical University, Changle Road 68, Nanjing, 210006, China.
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Gilbert ME, O'Shaughnessy KL, Thomas SE, Riutta C, Wood CR, Smith A, Oshiro WO, Ford RL, Hotchkiss MG, Hassan I, Ford JL. Thyroid Disruptors: Extrathyroidal Sites of Chemical Action and Neurodevelopmental Outcome-An Examination Using Triclosan and Perfluorohexane Sulfonate. Toxicol Sci 2021; 183:195-213. [PMID: 34460931 PMCID: PMC9038230 DOI: 10.1093/toxsci/kfab080] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Many xenobiotics are identified as potential thyroid disruptors due to their action to reduce circulating levels of thyroid hormone, most notably thyroxine (T4). Developmental neurotoxicity is a primary concern for thyroid disrupting chemicals yet correlating the impact of chemically induced changes in serum T4 to perturbed brain development remains elusive. A number of thyroid-specific neurodevelopmental assays have been proposed, based largely on the model thyroid hormone synthesis inhibitor propylthiouracil (PTU). This study examined whether thyroid disrupting chemicals acting distinct from synthesis inhibition would result in the same alterations in brain as expected with PTU. The perfluoroalkyl substance perfluorohexane sulfonate (50 mg/kg/day) and the antimicrobial Triclosan (300 mg/kg/day) were administered to pregnant rats from gestational day 6 to postnatal day (PN) 21, and a number of PTU-defined assays for neurotoxicity evaluated. Both chemicals reduced serum T4 but did not increase thyroid stimulating hormone. Both chemicals increased expression of hepatic metabolism genes, while thyroid hormone-responsive genes in the liver, thyroid gland, and brain were largely unchanged. Brain tissue T4 was reduced in newborns, but despite persistent T4 reductions in serum, had recovered in the PN6 pup brain. Neither treatment resulted in a low dose PTU-like phenotype in either brain morphology or neurobehavior, raising questions for the interpretation of serum biomarkers in regulatory toxicology. They further suggest that reliance on serum hormones as prescriptive of specific neurodevelopmental outcomes may be too simplistic and to understand thyroid-mediated neurotoxicity we must expand our thinking beyond that which follows thyroid hormone synthesis inhibition.
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Affiliation(s)
- Mary E Gilbert
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Katherine L O'Shaughnessy
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Susan E Thomas
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Cal Riutta
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Carmen R Wood
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Alicia Smith
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Wendy O Oshiro
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Richard L Ford
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Michelle Gatien Hotchkiss
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Iman Hassan
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Jermaine L Ford
- Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
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Hernandez A, Martinez ME, Ng L, Forrest D. Thyroid Hormone Deiodinases: Dynamic Switches in Developmental Transitions. Endocrinology 2021; 162:bqab091. [PMID: 33963379 PMCID: PMC8248586 DOI: 10.1210/endocr/bqab091] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Indexed: 12/15/2022]
Abstract
Thyroid hormones exert pleiotropic, essential actions in mammalian, including human, development. These actions depend on provision of thyroid hormones in the circulation but also to a remarkable extent on deiodinase enzymes in target tissues that amplify or deplete the local concentration of the primary active form of the hormone T3 (3,5,3'-triiodothyronine), the high affinity ligand for thyroid hormone receptors. Genetic analyses in mice have revealed key roles for activating (DIO2) and inactivating (DIO3) deiodinases in cell differentiation fates and tissue maturation, ultimately promoting neonatal viability, growth, fertility, brain development, and behavior, as well as metabolic, endocrine, and sensory functions. An emerging paradigm is how the opposing activities of DIO2 and DIO3 are coordinated, providing a dynamic switch that controls the developmental timing of a tissue response, often during neonatal and maturational transitions. A second paradigm is how cell to cell communication within a tissue determines the response to T3. Deiodinases in specific cell types, often strategically located near to blood vessels that convey thyroid hormones into the tissue, can regulate neighboring cell types, suggesting a paracrine-like layer of control of T3 action. We discuss deiodinases as switches for developmental transitions and their potential to influence tissue dysfunction in human thyroid disorders.
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Affiliation(s)
- Arturo Hernandez
- Department of Molecular Medicine, Maine Medical Center Research Institute, Maine Health, Scarborough, Maine 04074, USA
- Department of Medicine, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, USA
| | - M Elena Martinez
- Department of Molecular Medicine, Maine Medical Center Research Institute, Maine Health, Scarborough, Maine 04074, USA
| | - Lily Ng
- National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Endocrinology and Receptor Biology, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Douglas Forrest
- National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Endocrinology and Receptor Biology, National Institutes of Health, Bethesda, Maryland 20892, USA
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Sebastiano M, Jouanneau W, Blévin P, Angelier F, Parenteau C, Gernigon J, Lemesle JC, Robin F, Pardon P, Budzinski H, Labadie P, Chastel O. High levels of fluoroalkyl substances and potential disruption of thyroid hormones in three gull species from South Western France. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:144611. [PMID: 33385816 DOI: 10.1016/j.scitotenv.2020.144611] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/08/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) raised increasing concerns over the past years due to their persistence and global distribution. Understanding their occurrence in the environment and their disruptive effect on the physiology of humans and wildlife remains a major challenge in ecotoxicological studies. Here, we investigate the occurrence of several carboxylic and sulfonic PFAS in 105 individuals of three seabird species (27 great black-backed gull Larus marinus; 44 lesser black-backed gull Larus fuscus graellsii; and 34 European herring gull Larus argentatus) from South western France. We further estimated the relationship between plasma concentrations of PFAS and i) the body condition of the birds and ii) plasma concentrations of thyroid hormone triiodothyronine (TT3). We found that great and lesser black-backed gulls from South Western France are exposed to PFAS levels comparable to highly contaminated species from other geographical areas, although major emission sources (i.e. related to industrial activities) are absent in the region. We additionally found that PFAS are negatively associated with the body condition of the birds in two of the studied species, and that these results are sex-dependent. Finally, we found positive associations between exposure to PFAS and TT3 in the great black-backed gull, suggesting a potential disrupting mechanism of PFAS exposure. Although only three years of data have been collected, we investigated PFAS trend over the study period, and found that great black-backed gulls document an increasing trend of plasma PFAS concentration from 2016 to 2018. Because PFAS might have detrimental effects on birds, French seabird populations should be monitored since an increase of PFAS exposure may impact on population viability both in the short- and long-term.
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Affiliation(s)
- M Sebastiano
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-Univ. La Rochelle, France.
| | - W Jouanneau
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-Univ. La Rochelle, France
| | - P Blévin
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-Univ. La Rochelle, France; Akvaplan-niva AS, Fram Centre, NO-9296 Tromsø, Norway
| | - F Angelier
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-Univ. La Rochelle, France
| | - C Parenteau
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-Univ. La Rochelle, France
| | - J Gernigon
- Réserve Naturelle de Lilleau des Niges, 17880, France
| | - J C Lemesle
- Réserve Naturelle de Lilleau des Niges, 17880, France
| | - F Robin
- Réserve Naturelle de Lilleau des Niges, 17880, France; Ligue pour la Protection des Oiseaux (LPO), 17300 Rochefort, France
| | - P Pardon
- Univ. Bordeaux, CNRS, EPOC, EPHE, UMR 5805, F-33600 Pessac, France
| | - H Budzinski
- Univ. Bordeaux, CNRS, EPOC, EPHE, UMR 5805, F-33600 Pessac, France
| | - P Labadie
- Univ. Bordeaux, CNRS, EPOC, EPHE, UMR 5805, F-33600 Pessac, France
| | - O Chastel
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-Univ. La Rochelle, France
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Ramskov Tetzlaff CN, Ramhøj L, Lardenois A, Axelstad M, Evrard B, Chalmel F, Taxvig C, Svingen T. Adult female rats perinatally exposed to perfluorohexane sulfonate (PFHxS) and a mixture of endocrine disruptors display increased body/fat weights without a transcriptional footprint in fat cells. Toxicol Lett 2021; 339:78-87. [DOI: 10.1016/j.toxlet.2020.12.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 12/22/2020] [Accepted: 12/26/2020] [Indexed: 12/11/2022]
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Cho SW, Park YJ. Best Achievements in Translational and Basic Thyroidology in 2020. Endocrinol Metab (Seoul) 2021; 36:36-40. [PMID: 33677924 PMCID: PMC7937842 DOI: 10.3803/enm.2021.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/31/2021] [Indexed: 11/11/2022] Open
Abstract
This review discusses articles published in 2020 that presented noteworthy achievements in translational and basic thyroidology. Previously unresolved questions about thyroid hormone receptor actions and signaling mechanisms were answered using various novel in vitro and in vivo models. Using high resolution cryo-electron microscopy, the fine functional structure of thyroglobulin was demonstrated, and new insights into the pathogenesis of thyroid disease were achieved, with a focus on research into thyroid-disrupting chemicals and the gut microbiome. Novel therapeutic approaches were tried in the field of advanced thyroid cancer treatments.
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Affiliation(s)
- Sun Wook Cho
- Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Young Joo Park
- Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Seoul National University, Seoul, Korea
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Andersen SL, Andersen S. Hyperthyroidism in pregnancy: evidence and hypothesis in fetal programming and development. Endocr Connect 2021; 10:R77-R86. [PMID: 33444223 PMCID: PMC7983517 DOI: 10.1530/ec-20-0518] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/06/2021] [Indexed: 12/19/2022]
Abstract
The management of hyperthyroidism in pregnant patients has been a topic of raised clinical awareness for decades. It is a strong recommendation that overt hyperthyroidism of Graves' disease in pregnant women should be treated to prevent complications. The consequences of hyperthyroidism in pregnancy are less studied than hypothyroidism, and a literature review illustrates that the main burden of evidence to support current clinical guidance emerges from early observations of severe complications in Graves' disease patients suffering from untreated hyperthyroidism in the pregnancy. On the other hand, the more long-term consequences in children born to mothers with hyperthyroidism are less clear. A hypothesis of fetal programming by maternal hyperthyroidism implies that excessive levels of maternal thyroid hormones impair fetal growth and development. Evidence from experimental studies provides clues on such mechanisms and report adverse developmental abnormalities in the fetal brain and other organs. Only few human studies addressed developmental outcomes in children born to mothers with hyperthyroidism and did not consistently support an association. In contrast, large observational human studies performed within the last decade substantiate a risk of teratogenic side effects to the use of antithyroid drugs in early pregnancy. Thus, scientific and clinical practice are challenged by the distinct role of the various exposures associated with Graves' disease including the hyperthyroidism per se, the treatment, and thyroid autoimmunity. More basic and clinical studies are needed to extend knowledge on the effects of each exposure, on the potential interaction between exposures and with other determinants, and on the underlying mechanisms.
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Affiliation(s)
- Stine Linding Andersen
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
- Correspondence should be addressed to S L Andersen:
| | - Stig Andersen
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
- Department of Geriatrics, Aalborg University Hospital, Aalborg, Denmark
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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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Bonomo MM, Sachi ITDC, Paulino MG, Fernandes JB, Carlos RM, Fernandes MN. Multi-biomarkers approach to access the impact of novel metal-insecticide based on flavonoid hesperidin on fish. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115758. [PMID: 33022572 DOI: 10.1016/j.envpol.2020.115758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/22/2020] [Accepted: 09/26/2020] [Indexed: 06/11/2023]
Abstract
Aquatic ecosystem health is the main concern to increasing pesticides application to control agricultural pests as it is the ultimate receptor of such materials. This study evaluated the impact of new metal-insecticide, the [Mg(hesp)2(phen)], referred as MgHP, on fish using physiological, genetic, biochemical, and morphological biomarkers. The fish, Prochilodus lineatus, was exposed to 0 (control), 1, 10, 100, 1000 μg L-1 MgHP, for 24 and 96 h. MgHP was not lethal but caused genotoxicity, altered hematological variables and, the activity of antioxidant and biotransformation enzymes and histology of liver, depending on concentration and time exposure. Hematocrit and erythrocyte number (RBC) increased without change hemoglobin content resulting in changes in hematimetric indexes after 24 h; after 96 h, only RBC was changed. Erythrocyte nuclear abnormalities and crenate cells increased after 24 h but, not after 96 h. Erythrocytes and hepatocytes indicated instability in DNA integrity however, the absence of micronuclei suggested DNA damage repairment. After 24 h, the antioxidant defense system and the phase II biotransformation enzyme was responsiveness and catalase activity decreased at high MgHP concentrations; the antioxidant response was triggered after 96 h. Hepatocyte hypertrophy, intracellular cytoplasmic substances, cytoplasm degeneration, melanomacrophage and hyperemia increased in fish exposed from 10 μg L-1 to higher MgHP concentrations; the organ alteration index increased as MgHP concentration increased showing dose-dependence. Most of hematological and genotoxic effects occurred after 24 h exposure evidencing potential recover capability of organism by activation of the antioxidant defense system and DNA repairment mechanisms. Nevertheless, the histopathological changes in the liver was maintained over time at high MgHP concentrations, a concentration usually no environmental relevant. In conclusion, this data reinforced the importance of continuing research on MgHP effects in other organisms considering the promising use of such compound to control the leaf-cutter ants and other insects.
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Affiliation(s)
- Marina Marques Bonomo
- Postgraduate Program in Ecology and Natural Resources, Federal University of São Carlos, Washington Luiz Highway, km 235, 13565-905, São Carlos, SP, Brazil; Physiological Sciences Department, Federal University of São Carlos, Av. Washington Luiz Km 235, 13565-905, São Carlos, São Paulo, Brazil.
| | - Ivelise Teresa de Castro Sachi
- Postgraduate Program in Ecology and Natural Resources, Federal University of São Carlos, Washington Luiz Highway, km 235, 13565-905, São Carlos, SP, Brazil; Physiological Sciences Department, Federal University of São Carlos, Av. Washington Luiz Km 235, 13565-905, São Carlos, São Paulo, Brazil.
| | - Marcelo Gustavo Paulino
- Federal University of Tocantins, Campus Araguaína, Avenida Paraguai, s/n°, Setor Cimba, 77824-838, Araguaína, TO, Brazil.
| | - João Batista Fernandes
- Chemistry Department, Federal University of São Carlos, Av. Washington Luiz Km 235, 13565-905, São Carlos, São Paulo, Brazil.
| | - Rose Maria Carlos
- Chemistry Department, Federal University of São Carlos, Av. Washington Luiz Km 235, 13565-905, São Carlos, São Paulo, Brazil.
| | - Marisa Narciso Fernandes
- Postgraduate Program in Ecology and Natural Resources, Federal University of São Carlos, Washington Luiz Highway, km 235, 13565-905, São Carlos, SP, Brazil; Physiological Sciences Department, Federal University of São Carlos, Av. Washington Luiz Km 235, 13565-905, São Carlos, São Paulo, Brazil.
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Gilbert ME, O'Shaughnessy KL, Axelstad M. Regulation of Thyroid-disrupting Chemicals to Protect the Developing Brain. Endocrinology 2020; 161:bqaa106. [PMID: 32615585 PMCID: PMC8650774 DOI: 10.1210/endocr/bqaa106] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/30/2020] [Indexed: 12/18/2022]
Abstract
Synthetic chemicals with endocrine disrupting properties are pervasive in the environment and are present in the bodies of humans and wildlife. As thyroid hormones (THs) control normal brain development, and maternal hypothyroxinemia is associated with neurological impairments in children, chemicals that interfere with TH signaling are of considerable concern for children's health. However, identifying thyroid-disrupting chemicals (TDCs) in vivo is largely based on measuring serum tetraiodothyronine in rats, which may be inadequate to assess TDCs with disparate mechanisms of action and insufficient to evaluate the potential neurotoxicity of TDCs. In this review 2 neurodevelopmental processes that are dependent on TH action are highlighted, neuronal migration and maturation of gamma amino butyric acid-ergic interneurons. We discuss how interruption of these processes by TDCs may contribute to abnormal brain circuitry following developmental TH insufficiency. Finally, we identify issues in evaluating the developmental neurotoxicity of TDCs and the strengths and limitations of current approaches designed to regulate them. It is clear that an enhanced understanding of how THs affect brain development will lead to refined toxicity testing, reducing uncertainty and improving our ability to protect children's health.
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Affiliation(s)
- Mary E Gilbert
- Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Research Triangle Park, North Carolina
| | - Katherine L O'Shaughnessy
- Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Research Triangle Park, North Carolina
| | - Marta Axelstad
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
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Coperchini F, Croce L, Ricci G, Magri F, Rotondi M, Imbriani M, Chiovato L. Thyroid Disrupting Effects of Old and New Generation PFAS. Front Endocrinol (Lausanne) 2020; 11:612320. [PMID: 33542707 PMCID: PMC7851056 DOI: 10.3389/fendo.2020.612320] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/04/2020] [Indexed: 12/25/2022] Open
Abstract
Per- and polyfluoroalkyl substances (PFAS) represent a group of synthetic compounds widely used in industry plants due to their low grade of degradation, surfactant properties, thermic and flame resistance. These characteristics are useful for the industrial production, however they are also potentially dangerous for human health and for the environment. PFAS are persistent pollutants accumulating in waters and soil and recoverable in foods due to their release by food packaging. Humans are daily exposed to PFAS because these compounds are ubiquitous and, when assimilated, they are difficult to be eliminated, persisting for years both in humans and animals. Due to their persistence and potential danger to health, some old generation PFAS have been replaced by newly synthesized PFAS with the aim to use alternative compounds presumably safer for humans and the environment. Yet, the environmental pollution with PFAS remains a matter of concern worldwide and led to large-scale epidemiological studies both on plants' workers and on exposed people in the general population. In this context, strong concern emerged concerning the potential adverse effects of PFAS on the thyroid gland. Thyroid hormones play a critical role in the regulation of metabolism, and thyroid function is related to cardiovascular disease, fertility, and fetal neurodevelopment. In vitro, ex vivo data, and epidemiological studies suggested that PFASs may disrupt the thyroid hormone system in humans, with possible negative repercussions on the outcome of pregnancy and fetal-child development. However, data on the thyroid disrupting effect of PFAS remain controversial, as well as their impact on human health in different ages of life. Aim of the present paper is to review recent data on the effects of old and new generation PFAS on thyroid homeostasis. To this purpose we collected information from in vitro studies, animal models, and in vivo data on exposed workers, general population, and pregnant women.
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Affiliation(s)
- Francesca Coperchini
- Laboratory for Endocrine Disruptors, Unit of Internal Medicine and Endocrinology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
| | - Laura Croce
- Laboratory for Endocrine Disruptors, Unit of Internal Medicine and Endocrinology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
| | - Gianluca Ricci
- Laboratory for Endocrine Disruptors, Unit of Internal Medicine and Endocrinology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
| | - Flavia Magri
- Laboratory for Endocrine Disruptors, Unit of Internal Medicine and Endocrinology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
| | - Mario Rotondi
- Laboratory for Endocrine Disruptors, Unit of Internal Medicine and Endocrinology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
| | - Marcello Imbriani
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy
| | - Luca Chiovato
- Laboratory for Endocrine Disruptors, Unit of Internal Medicine and Endocrinology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
- *Correspondence: Luca Chiovato,
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