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Du Pasquier D, Salinier B, Coady KK, Jones A, Körner O, LaRocca J, Lemkine G, Robin-Duchesne B, Weltje L, Wheeler JR, Lagadic L. How the Xenopus eleutheroembryonic thyroid assay compares to the amphibian metamorphosis assay for detecting thyroid active chemicals. Regul Toxicol Pharmacol 2024; 149:105619. [PMID: 38614220 DOI: 10.1016/j.yrtph.2024.105619] [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: 11/27/2023] [Revised: 02/05/2024] [Accepted: 04/03/2024] [Indexed: 04/15/2024]
Abstract
The Xenopus Eleutheroembryonic Thyroid Assay (XETA) was recently published as an OECD Test Guideline for detecting chemicals acting on the thyroid axis. However, the OECD validation did not cover all mechanisms that can potentially be detected by the XETA. This study was therefore initiated to investigate and consolidate the applicability domain of the XETA regarding the following mechanisms: thyroid hormone receptor (THR) agonism, sodium-iodide symporter (NIS) inhibition, thyroperoxidase (TPO) inhibition, deiodinase (DIO) inhibition, glucocorticoid receptor (GR) agonism, and uridine 5'-diphospho-glucuronosyltransferase (UDPGT) induction. In total, 22 chemicals identified as thyroid-active or -inactive in Amphibian Metamorphosis Assays (AMAs) were tested using the XETA OECD Test Guideline. The comparison showed that both assays are highly concordant in identifying chemicals with mechanisms of action related to THR agonism, DIO inhibition, and GR agonism. They also consistently identified the UDPGT inducers as thyroid inactive. NIS inhibition, investigated using sodium perchlorate, was not detected in the XETA. TPO inhibition requires further mechanistic investigations as the reference chemicals tested resulted in opposing response directions in the XETA and AMA. This study contributes refining the applicability domain of the XETA, thereby helping to clarify the conditions where it can be used as an ethical alternative to the AMA.
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Affiliation(s)
- David Du Pasquier
- Laboratoire WatchFrog, 1 Rue Pierre Fontaine, 91000, Évry-Courcouronnes, France
| | - Benoît Salinier
- Laboratoire WatchFrog, 1 Rue Pierre Fontaine, 91000, Évry-Courcouronnes, France
| | - Katherine K Coady
- Bayer Crop Science, Environmental Safety, 700 Chesterfield Parkway West, Chesterfield, MO, USA
| | - Alan Jones
- ADAMA US, Environmental Safety, 3120 Highwoods Blvd., Raleigh, NC, 27604, USA
| | - Oliver Körner
- ADAMA, Environmental Safety, Edmund-Rumpler-Strasse 6, 51149, Cologne, Germany
| | - Jessica LaRocca
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, IN, 46268, USA
| | - Gregory Lemkine
- Laboratoire WatchFrog, 1 Rue Pierre Fontaine, 91000, Évry-Courcouronnes, France
| | | | - Lennart Weltje
- BASF SE, Agricultural Solutions - Ecotoxicology, Speyerer Strasse 2, 67117, Limburgerhof, Germany
| | - James R Wheeler
- Corteva Agriscience, Zuid-Oostsingel 24D, 4611 BB, Bergen op Zoom, the Netherlands
| | - Laurent Lagadic
- Bayer AG R&D Crop Science, Alfred-Nobel-Strasse 50, 40789, Monheim am Rhein, Germany.
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Egalini F, Marinelli L, Rossi M, Motta G, Prencipe N, Rossetto Giaccherino R, Pagano L, Grottoli S, Giordano R. Endocrine disrupting chemicals: effects on pituitary, thyroid and adrenal glands. Endocrine 2022; 78:395-405. [PMID: 35604630 PMCID: PMC9637063 DOI: 10.1007/s12020-022-03076-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 05/08/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND In recent years, scientific research has increasingly focused on Endocrine Disrupting Chemicals (EDCs) and demonstrated their relevant role in the functional impairment of endocrine glands. This induced regulatory authorities to ban some of these compounds and to carefully investigate others in order to prevent EDCs-related conditions. As a result, we witnessed a growing awareness and interest on this topic. AIMS This paper aims to summarize current evidence regarding the detrimental effects of EDCs on pivotal endocrine glands like pituitary, thyroid and adrenal ones. Particularly, we directed our attention on the known and the hypothesized mechanisms of endocrine dysfunction brought by EDCs. We also gave a glimpse on recent findings from pioneering studies that could in the future shed a light on the pathophysiology of well-known, but poorly understood, endocrine diseases like hormone-producing adenomas. CONCLUSIONS Although intriguing, studies on endocrine dysfunctions brought by EDCs are challenging, in particular when investigating long-term effects of EDCs on humans. However, undoubtedly, it represents a new intriguing field of science research.
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Affiliation(s)
- Filippo Egalini
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy.
| | - Lorenzo Marinelli
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Mattia Rossi
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Giovanna Motta
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Nunzia Prencipe
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Ruth Rossetto Giaccherino
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Loredana Pagano
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Silvia Grottoli
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Roberta Giordano
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
- Department of Biological and Clinical Science, University of Turin, Regione Gonzole 10, 10043, Orbassano (TO), Italy
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Thyroid hormones during the perinatal period are necessary to respiratory network development of newborn rats. Exp Neurol 2021; 345:113813. [PMID: 34284029 DOI: 10.1016/j.expneurol.2021.113813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 06/09/2021] [Accepted: 07/14/2021] [Indexed: 10/20/2022]
Abstract
Thyroid hormones (THs) are essential for foetal brain development. Because the gestating mother is the main source of THs to the foetus, maternal hypothyroidism and/or premature birth compromise neurological outcomes in the offspring. Respiratory instability and recurrent apneas due to immaturity of the respiratory control network are major causes of morbidity in infants. Inadequate TH supply may be sufficient to delay perinatal maturation of the respiratory control system; however, this hypothesis remains untested. To address this issue, maternal hypothyroidism was induced by adding methimazole (MMI; 0.02% w/v) to the drinking water of pregnant dams from conception to postpartum day 4 (P4). The effect of TH supplementation on respiratory function was tested by injecting levothyroxine (L-T4) in newborns at P1. Respiratory function was assessed by plethysmography (in vivo) and recording of phrenic output from medullary preparations (in vitro). By comparison with controls, TH deficiency increased the frequency of apneas and decreased basal ventilation in vivo and prevented the age-dependent increase in phrenic burst frequency normally observed in vitro. The effects of TH deficiency on GABAergic modulation of respiratory activity were measured by bath application of muscimol (GABAA agonist) or bicuculline (GABAA antagonist). The phrenic burst frequency responses to GABAergic agents were consistently greater in preparations from TH deficient pups. L-T4 supplementation reversed part of the respiratory anomalies related to MMI treatment in vitro. We conclude that TH deficiency during the perinatal period is sufficient to delay maturation of the respiratory control network development. Excessive GABAergic inhibition may contribute to this effect.
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Effect of Subclinical and Overt Form of Rat Maternal Hypothyroidism on Offspring Endochondral Bone Formation. ACTA VET-BEOGRAD 2018. [DOI: 10.2478/acve-2018-0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Abstract
Maternal hypothyroidism in its overt form affects skeletal development of the offspring, but these data are not available for the subclinical form which is becoming very frequent among pregnant women. We hypothesized that the subclinical form of hypothyroidism in rat dams, infl uences the process of offspring endochondral ossifi cation affecting proliferation and differentiation of chondrocytes, osteoclasts and osteoblasts in pups. Seven-day-old male pups (n=18) derived from control dams and dams treated with a low dose (1.5 mg/L) or high dose (150 mg/L) of propylthiouracil in drinking water during pregnancy and lactation were used. Histomorphometric analysis of pups’ tibia proximal growth plate, expression of mRNA, immunohistochemical and histochemical visualization of extracellular matrix components was performed. The length of the tibia was reduced in hypothyroid pups. Secretion of type 2 and 10 collagens in the subclinical and overt form were lower while the amount of glycosaminoglycans was higher when compared with controls. Down-regulated tartrate resistant acid phosphatase mRNA indicated altered osteoclasts function while lower expression of dentin matrix acid protein-1 mRNA and reduced synthesis of type 1 collagen accentuated a compromised bone formation in the overt form of hypothyroidism. The subclinical form of maternal hypothyroidism had a negative effect on the differentiation of hypertrophic chondrocytes and calcifi ed cartilage removal in 7-day-old pups. In addition, overt hypothyroidism had a negative effect on the proliferation of chondrocytes and deposition of osteoid. Both forms of hypothyroidism resulted in a decrease of tibia length due to changes in growth plate formation.
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Maternal hypothyroidism: An overview of current experimental models. Life Sci 2017; 187:1-8. [DOI: 10.1016/j.lfs.2017.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/18/2017] [Accepted: 08/10/2017] [Indexed: 01/07/2023]
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Wegner S, Browne P, Dix D. Identifying reference chemicals for thyroid bioactivity screening. Reprod Toxicol 2016; 65:402-413. [PMID: 27589887 DOI: 10.1016/j.reprotox.2016.08.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 08/19/2016] [Accepted: 08/29/2016] [Indexed: 12/20/2022]
Abstract
Reference chemicals were selected based on thyroid bioactivity in 'Tier 1' screening assays used by the U.S. EPA's Endocrine Disruptor Screening Program. Active reference chemicals had significant effects on thyroid-responsive endpoints in the amphibian metamorphosis assay, and the male and female pubertal rat assays. In the absence of thyroid weight or histopathological effects, additional published studies providing mechanistic data on thyroid activity were required for active chemicals. Inactive reference chemicals had no significant effects on thyroid-responsive endpoints in Tier 1 assays, or in amphibian or rodent studies from several online databases. The 34 reference chemicals (29 active and five inactive) will be useful for performance-based validation of alternative, high throughput screening assays for thyroid bioactivity.
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Affiliation(s)
- Susanna Wegner
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, United States.
| | - Patience Browne
- Office of Science Coordination and Policy (OSCP), Office of Chemical Safety and Pollution Prevention, U.S. EPA, Washington, D.C., United States
| | - David Dix
- Office of Science Coordination and Policy (OSCP), Office of Chemical Safety and Pollution Prevention, U.S. EPA, Washington, D.C., United States
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Ahmed RG, Abdel-Latif M, Ahmed F. Protective effects of GM-CSF in experimental neonatal hypothyroidism. Int Immunopharmacol 2015; 29:538-543. [PMID: 26453507 DOI: 10.1016/j.intimp.2015.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/27/2015] [Accepted: 10/01/2015] [Indexed: 12/18/2022]
Abstract
Hypothyroidism induced by methimazole (MMI), has a negative impact on the postnatal development. Neonatal Granulocyte Macrophage-Colony Stimulating Factor [GM-CSF; 50μg/kg, intramuscular injection at postnatal day (PND) 17] had been tested to ameliorate the effects of MMI [0.05%, (weight per volume; w/v), intraperitoneal injection at PND 15]-induced hypothyroidism in Wistar rats. The hypothyroid conditions due to the administration of MMI produced inhibitory effects on neonatal serum thyroxine (T4), 3,5,3'-triiodothyronine (T3), neutrophil count in bone marrow and blood, cerebellar glutathione (GSH) and acetylcholinesterase (AchE), although it induced stimulatory actions on serum thyrotropin (TSH), growth hormone (GH), insulin growth factor-II (IGF-II), tumor necrosis factor alpha (TNF-α), and cerebellar malondialdehyde (MDA) at PND 19. The treatment with GM-CSF could reverse the depressing and stimulating effects of MMI on these markers except for cerebellar AchE where its enhancement was non-significant (P>0.05) at tested PND. Thus, neonatal GM-CSF may be responsible for suppressing autoimmune responses and preventing hypothyroidism.
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Affiliation(s)
- R G Ahmed
- Division of Anatomy and Embryology, Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt.
| | - M Abdel-Latif
- Division of Immunity, Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | - F Ahmed
- Immunity and Microbiology Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
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Li JE, Futawaka K, Yamamoto H, Kasahara M, Tagami T, Liu TH, Moriyama K. Cinnamaldehyde Contributes to Insulin Sensitivity by Activating PPARδ, PPARγ, and RXR. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2015; 43:879-92. [PMID: 26227398 DOI: 10.1142/s0192415x15500512] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cinnamon is a traditional folk herb used in Asia and has been reported to have antidiabetic effects. Our previous study showed that cinnamaldehyde (CA), a major effective compound in cinnamon, exhibited hypoglycemic and hypolipidemic effects together in db/db mice. The aim of the present study was to elucidate the molecular mechanisms of the effects of CA on the transcriptional activities of three peroxisome proliferator-activated receptors, (PPAR) α, δ, and γ. We studied the effects of CA through a transient expression assay with TSA201 cells, derivatives of human embryonic kidney cell line (HEK293). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was also performed to evaluate mRNA expression levels. We show here that CA induced PPARδ, PPARγ and retinoid X receptor (RXR) activation. CA may activate PPARγ in a different manner than pioglitazone, as CA selectively stimulated PPARγ S342A mutant while pioglitazone did not. In addition, CA and L-165041 had a synergistic effect on PPARδ activation. To gather the biological evidence that CA increases PPARs transcription, we further measured the expressions of PPARδ and PPARγ target genes in 3T3-L1 adipocytes. The data showed CA induced the expression of PPARδ and PPARγ target genes, namely aP2 and CD36, in differentiated adipocytes. As a result, PPARδ, PPARγ and their heterodimeric partner RXR appear to play a part in the CA action in the target tissues, thereby enhancing insulin sensitivity and fatty acid β-oxidation and energy uncoupling in skeletal muscle and adipose tissue.
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Affiliation(s)
- Juan-E Li
- Department of Chinese Medicine, Shaanxi Provincial People's Hospital, Xi'an 710068, China.,Graduate School, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Kumi Futawaka
- Department of Medicine and Clinical Science, School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya 663-8179, Japan
| | - Hiroyuki Yamamoto
- Department of Medicine and Clinical Science, School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya 663-8179, Japan
| | - Masato Kasahara
- Department of Nephrology and Blood Purification, Institute of Biomedical Research and Innovation, Kobe Medical Frontier Center, Kobe 650-0047, Japan
| | - Tetsuya Tagami
- Clinical Research Institute, Kyoto Medical Center, National Hospital Organization, Kyoto 612-8555, Japan
| | - Tong-Hua Liu
- Graduate School, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Kenji Moriyama
- Department of Medicine and Clinical Science, School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya 663-8179, Japan.,Clinical Research Institute, Kyoto Medical Center, National Hospital Organization, Kyoto 612-8555, Japan
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Abstract
INTRODUCTION Antithyroid drugs (ATDs) are used in the treatment of hyperthyroidism. Very rarely ATDs were reported to trigger acute psychosis in patients with no history of psychiatric disturbances. Our aim is to review the literature on psychosis as a side effect of ATD and to give a personal opinion on this issue. AREAS COVERED The cases of acute psychosis elicited by ATD are few and most were reported many years ago, before radioimmunoassay for thyroid-stimulating hormone (TSH) and thyroid hormones was introduced. Most of those cases lack a description of serum thyroid hormone profile before, during and after the appearance of the psychiatric disorder; hence, an abrupt shift from hyperthyroidism to euthyroidism or hypothyroidism cannot be excluded. In addition, patients underwent specific psychiatric therapy, so that it is difficult to attribute the disappearance of the mental disorders to the withdrawal of ATD per se. EXPERT OPINION Patients who develop mental disorders while under ATD should be followed by an accurate evaluation of TSH, free triiodothyronine (FT3), and free thyroxine (FT4) levels throughout the course of the psychiatric disease. The use of new imaging techniques could be helpful in ruling out the encephalopathy associated with autoimmune thyroid diseases and other cerebral pathologies that might be possible causes of these mental disorders.
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Affiliation(s)
- Roberto Vita
- University of Messina, Department of Clinical & Experimental Medicine, Section of Endocrinology , Viale Gazzi, Padiglione H, 4 piano, 98125 Messina , Italy +39 090 221 3560 ; +39 090 2213518 ;
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Van Herck SLJ, Geysens S, Bald E, Chwatko G, Delezie E, Dianati E, Ahmed RG, Darras VM. Maternal transfer of methimazole and effects on thyroid hormone availability in embryonic tissues. J Endocrinol 2013; 218:105-15. [PMID: 23608220 DOI: 10.1530/joe-13-0089] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Methimazole (MMI) is an anti-thyroid drug used in the treatment of chronic hyperthyroidism. There is, however, some debate about its use during pregnancy as MMI is known to cross the mammalian placenta and reach the developing foetus. A similar problem occurs in birds, where MMI is deposited in the egg and taken up by the developing embryo. To investigate whether maternally derived MMI can have detrimental effects on embryonic development, we treated laying hens with MMI (0.03% in drinking water) and measured total and reduced MMI contents in the tissues of hens and embryos at different stages of development. In hens, MMI was selectively increased in the thyroid gland, while its levels in the liver and especially brain remained relatively low. Long-term MMI treatment induced a pronounced goitre with a decrease in thyroxine (T₄) content but an increase in thyroidal 3,5,3'-triiodothyronine (T₃) content. This resulted in normal T₃ levels in tissues except in the brain. In chicken embryos, MMI levels were similar in the liver and brain. They gradually decreased during development but always remained above those in the corresponding maternal tissues. Contrary to the situation in hens, T₄ availability was only moderately affected in embryos. Peripheral T₃ levels were reduced in 14-day-old embryos but normal in 18-day-old embryos, while brain T₃ content was decreased at all embryonic stages tested. We conclude that all embryonic tissues are exposed to relatively high doses of MMI and its oxidised metabolites. The effect of maternal MMI treatment on embryonic thyroid hormone availability is most pronounced for brain T₃ content, which is reduced throughout the embryonic development period.
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Affiliation(s)
- Stijn L J Van Herck
- Laboratory of Comparative Endocrinology, Department of Biology, KU Leuven, Naamsestraat 61, PB 2464, B-3000 Leuven, Belgium
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Wang Y, Zhong J, Xu H, Wei W, Dong J, Yu F, Wang Y, Gong J, Shan Z, Teng W, Chen J. Perinatal iodine deficiency and hypothyroidism increase cell apoptosis and alter doublecortin and reelin protein expressions in rat cerebellum. Arch Med Res 2012; 43:255-64. [PMID: 22595232 DOI: 10.1016/j.arcmed.2012.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 04/20/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND AIMS Adequate thyroid hormone is critical for cerebellar development. Developmental hypothyroidism induced by iodine deficiency during the perinatal period results in permanent impairments of cerebellar development with an unclear mechanism. In the present study we investigated effects of perinatal iodine deficiency and hypothyroidism on cerebellar cell apoptosis, doublecortin (Dcx) and reelin. Apoptosis is an essential part of neural development. Dcx and reelin are two important molecules involved in neuronal migration, structure, and development in cerebellum. METHODS Two developmental rat models were created by administering dam rats with either iodine-deficient diet or propylthiouracil (PTU, 5 ppm or 15 ppm)-added drinking water from gestational day (GD) 6 until postnatal day (PND) 28. TUNEL assay and protein levels of Dcx and reelin in cerebella were assessed on PND14, 21 and 28. RESULTS Apoptotic cells were increased in the iodine-deficient and PTU-treated rats. Dcx protein levels in the cerebella of iodine-deficient and PTU-treated rats were significantly downregulated on PND14. Interestingly, iodine deficiency and PTU treatment upregulated the levels of Dcx protein on PND21 and 28. Reelin expressions in iodine-deficient and PTU-treated rats were significantly decreased on PND14 and 21. On PND28, reelin expressions of three treated groups were still lower than control group, although without significant difference. CONCLUSIONS These findings may implicate alterations in cell apoptosis and levels of Dcx and reelin in the impairments of cerebellar development induced by developmental iodine deficiency and hypothyroidism.
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Affiliation(s)
- Yi Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, PR China
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Wang Y, Zhong J, Wei W, Gong J, Dong J, Yu F, Wang Y, Chen J. Developmental iodine deficiency and hypothyroidism impair neural development, upregulate caveolin-1, and downregulate synaptotagmin-1 in the rat cerebellum. Biol Trace Elem Res 2011; 144:1039-49. [PMID: 21611807 DOI: 10.1007/s12011-011-9089-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 05/16/2011] [Indexed: 01/30/2023]
Abstract
Adequate thyroid hormone is critical for cerebellar development. Developmental hypothyroidism induced by iodine deficiency during gestation and postnatal period results in permanent impairments of cerebellar development with an unclear mechanism. In the present study, we implicate cerebellar caveolin-1 and synaptotagmin-1, the two important molecules involved in neuronal development, in developmental iodine deficiency, and in developmental hypothyroidism. Two developmental rat models were created by administrating dam rats with either iodine-deficient diet or propylthiouracil (PTU, 5 or 15 ppm)-added drinking water from gestational day 6 till postnatal day (PN) 28. Nissl staining and the levels of caveolin-1 and synaptotagmin-1 in cerebella were assessed on PN28 and PN42. The results show that the numbers of Purkinje cells were reduced in the iodine-deficient and PTU-treated rats. The upregulation of caveolin-1 and the downregulation of synaptotagmin-1 were observed in both iodine-deficient and PTU-treated rats. These findings may implicate decreases in the number of Purkinje cells and the alterations in the levels of caveolin-1 and synaptotagmin-1 in the impairments of cerebellar development induced by developmental iodine deficiency and hypothyroidism.
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Affiliation(s)
- Yi Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, 92 North 2nd Road, Shenyang, 110001, People's Republic of China
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Du G, Shen O, Sun H, Fei J, Lu C, Song L, Xia Y, Wang S, Wang X. Assessing hormone receptor activities of pyrethroid insecticides and their metabolites in reporter gene assays. Toxicol Sci 2010; 116:58-66. [PMID: 20410157 DOI: 10.1093/toxsci/kfq120] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024] Open
Abstract
Pyrethroid insecticides, the most commonly used insecticides worldwide, are suspected endocrine-disrupting chemicals. But their interactions with hormone receptors are still unclear. The present study intended to evaluate and compare the hormone receptor (estrogen receptor [ER], androgen receptor [AR], and thyroid hormone receptor [TR]) activities of nine pyrethroids (cycloprothrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin, etofenprox, fenvalerate, permethrin, and tetramethrin) and their metabolites (3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropne carboxylic acid [DCCA] and 3-phenoxybenzoic acid [3-PBA]) using receptor-mediated luciferase reporter gene assays. Of the 11 compounds tested, four showed very weak ER agonistic activities and six displayed antiestrogenic effects, among which cyhalothrin and DCCA possessed the most potent estrogenic and antiestrogenic activity respectively. Antagonistic effects to AR were found in 7 compounds, with cyfluthrin and deltamethrin exhibiting stronger AR antagonistic capacity. In the TR assay, all of tested chemicals except DCCA showed antagonistic effects. In this study, we provided evidence that a variety of pyrethroids and their metabolites might disrupt the function of multiple nuclear hormone receptors and thus have the potentials to affect the endocrine and the reproductive systems in humans.
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Affiliation(s)
- Guizhen Du
- Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, China
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Tagami T. [Therapeutic guidelines--the current status and problems. 1. Chemotherapy of Basedow's disease]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 2010; 99:733-40. [PMID: 20578359 DOI: 10.2169/naika.99.733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Jugan ML, Levi Y, Blondeau JP. Endocrine disruptors and thyroid hormone physiology. Biochem Pharmacol 2009; 79:939-47. [PMID: 19913515 DOI: 10.1016/j.bcp.2009.11.006] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/25/2009] [Accepted: 11/03/2009] [Indexed: 02/07/2023]
Abstract
Endocrine disruptors are man-made chemicals that can disrupt the synthesis, circulating levels, and peripheral action of hormones. The disruption of sex hormones was subject of intensive research, but thyroid hormone synthesis and signaling are now also recognized as important targets of endocrine disruptors. The neurological development of mammals is largely dependent on normal thyroid hormone homeostasis, and it is likely to be particularly sensitive to disruption of the thyroid axis. Here, we survey the main thyroid-disrupting chemicals, such as polychlorinated biphenyls, perchlorates, and brominated flame-retardants, that are characteristic disruptors of thyroid hormone homeostasis, and look at their suspected relationships to impaired development of the human central nervous system. The review then focuses on disrupting mechanisms known to be directly or indirectly related to the transcriptional activity of the thyroid hormone receptors.
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Affiliation(s)
- Mary-Line Jugan
- Univ Paris-Sud 11, Faculté de Pharmacie, Laboratoire Santé Publique-Environnement, 92290 Châtenay-Malabry, France.
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Sun H, Shen OX, Xu XL, Song L, Wang XR. Carbaryl, 1-naphthol and 2-naphthol inhibit the beta-1 thyroid hormone receptor-mediated transcription in vitro. Toxicology 2008; 249:238-42. [PMID: 18584933 DOI: 10.1016/j.tox.2008.05.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 05/13/2008] [Accepted: 05/14/2008] [Indexed: 11/30/2022]
Abstract
Effects of pesticides on the function of thyroid have attracted lots of attention because thyroid hormones (THs) play a major role in mammalian brain development. In order to screen for compounds that acted on the thyroid hormone receptor (TR) signaling pathway, we transiently transfected the vector pGal4-L-TRbeta1 (Gal4 DBD fused to hTRbeta1 LBD) and Gal4-responsive luciferase reporter pUAS-tk-Luc into HepG2 cell, developing a reporter gene assay which showed good response to triiodothyronine (T3) and thyroxine (T4) with the median effective concentration (EC(50)) of 0.46 and 25.53 nM, respectively. Bisphenol A exhibited weak anti-thyroid hormone activity with median inhibitory concentration (IC(50)) value of 6.45 x 10(-5)M. The assay showed acceptable repeatability to T3 with intra coefficient of variability (CV) of 5.9% and inter CV of 11.7%. Carbaryl, 1-naphthol (1-NAP) and 2-naphthol (2-NAP) were tested for their agonist and antagonist activities. As a result, we found that all the three related chemicals possessed TR antagonist activity and none of them showed the agonist activity. These results further indicated that TR might be the targets of industrial chemicals. And this assay provided a useful tool for investigating the effects of environment chemicals on thyoid function.
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Affiliation(s)
- Hong Sun
- Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, China
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Kawakami Y, Yokoi K, Kumai H, Ohta H. The role of thyroid hormones during the development of eye pigmentation in the Pacific bluefin tuna (Thunnus orientalis). Comp Biochem Physiol B Biochem Mol Biol 2008; 150:112-6. [DOI: 10.1016/j.cbpb.2008.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2007] [Revised: 02/12/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
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