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Richard S, Ren J, Flamant F. Thyroid hormone action during GABAergic neuron maturation: The quest for mechanisms. Front Endocrinol (Lausanne) 2023; 14:1256877. [PMID: 37854197 PMCID: PMC10579935 DOI: 10.3389/fendo.2023.1256877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/18/2023] [Indexed: 10/20/2023] Open
Abstract
Thyroid hormone (TH) signaling plays a major role in mammalian brain development. Data obtained in the past years in animal models have pinpointed GABAergic neurons as a major target of TH signaling during development, which opens up new perspectives to further investigate the mechanisms by which TH affects brain development. The aim of the present review is to gather the available information about the involvement of TH in the maturation of GABAergic neurons. After giving an overview of the kinds of neurological disorders that may arise from disruption of TH signaling during brain development in humans, we will take a historical perspective to show how rodent models of hypothyroidism have gradually pointed to GABAergic neurons as a main target of TH signaling during brain development. The third part of this review underscores the challenges that are encountered when conducting gene expression studies to investigate the molecular mechanisms that are at play downstream of TH receptors during brain development. Unravelling the mechanisms of action of TH in the developing brain should help make progress in the prevention and treatment of several neurological disorders, including autism and epilepsy.
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Affiliation(s)
| | | | - Frédéric Flamant
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, USC1370 Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, Lyon, France
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2
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Ren J, Flamant F. Thyroid hormone as a temporal switch in mouse development. Eur Thyroid J 2023; 12:e220225. [PMID: 36715693 PMCID: PMC10083660 DOI: 10.1530/etj-22-0225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023] Open
Abstract
Thyroid hormones are known to trigger metamorphosis in an amphibian. This review discusses the hypothesis according to which they act in a similar manner to synchronize the post-natal development of mice, using brain, brown adipose tissue, and heart as examples.
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Affiliation(s)
- Juan Ren
- ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, Lyon, France
| | - Frédéric Flamant
- ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, Lyon, France
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3
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Wang S, Liu H, Cheng B, Wu Q, Li L, Yang T, Hou N, Li T. Vitamin A supplementation ameliorates motor incoordination via modulating RORα in the cerebellum in a valproic acid-treated rat autism model with vitamin A deficiency. Neurotoxicology 2021; 85:90-98. [PMID: 33991534 DOI: 10.1016/j.neuro.2021.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 10/21/2022]
Abstract
Motor dysfunctions are common comorbidities among autism spectrum disorder (ASD) patients. Abnormal cerebellar development throughout critical periods may have an effect on motor functions and result in motor impairments. Vitamin A (VA) plays a crucial role in the developing process of the nervous system. The correlation of VA deficiency (VAD) and ASD with motor dysfunctions, however, is not clear. Therefore, we built rat models with different VA levels based on the valproic acid (VPA)-treated autism model. ASD rats with VAD showed aggravated motor coordination abnormalities, Purkinje cell loss and impaired dendritic arborization of Purkinje cells compared to ASD rats with normal VA levels (VA normal, VAN). Additionally, the expression levels of retinoid-related orphan receptor α (RORα) and retinoic acid receptor α (RARα) were lower in the cerebellum of ASD rats with VAD than in those of ASD rats with VAN. VA supplementation (VAS) effectively improved motor coordination and cerebellar Purkinje cell abnormalities in ASD rats with VAD. Furthermore, the results of chromatin immunoprecipitation (ChIP) assays confirmed that the enrichment of RARα was detected on the RORα promoter in the cerebellum and that VAS could upregulate the binding capacity of RARα for RORα promoters. These results showed that VAD in autism might result in cerebellar impairments and be a factor aggravating a subtype of ASD with motor comorbidities. The therapeutic effect of VAS on motor deficits and Purkinje neuron impairments in autism might be due to the regulation of RORα by RARα.
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Affiliation(s)
- Si Wang
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China
| | - Huan Liu
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China
| | - Boli Cheng
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China
| | - Qionghui Wu
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China
| | - Lisha Li
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China
| | - Ting Yang
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China
| | - Nali Hou
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China; Department of Child Health Care, Children's Hospital of Chongqing Medical University, Chongqing, China.
| | - Tingyu Li
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Chongqing Key Laboratory of Child Nutrition and Health, Chongqing, China.
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4
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ERGO: Breaking Down the Wall between Human Health and Environmental Testing of Endocrine Disrupters. Int J Mol Sci 2020; 21:ijms21082954. [PMID: 32331419 PMCID: PMC7215679 DOI: 10.3390/ijms21082954] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/16/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022] Open
Abstract
ERGO (EndocRine Guideline Optimization) is the acronym of a European Union-funded research and innovation action, that aims to break down the wall between mammalian and non-mammalian vertebrate regulatory testing of endocrine disruptors (EDs), by identifying, developing and aligning thyroid-related biomarkers and endpoints (B/E) for the linkage of effects between vertebrate classes. To achieve this, an adverse outcome pathway (AOP) network covering various modes of thyroid hormone disruption (THD) in multiple vertebrate classes will be developed. The AOP development will be based on existing and new data from in vitro and in vivo experiments with fish, amphibians and mammals, using a battery of different THDs. This will provide the scientifically plausible and evidence-based foundation for the selection of B/E and assays in lower vertebrates, predictive of human health outcomes. These assays will be prioritized for validation at OECD (Organization for Economic Cooperation and Development) level. ERGO will re-think ED testing strategies from in silico methods to in vivo testing and develop, optimize and validate existing in vivo and early life-stage OECD guidelines, as well as new in vitro protocols for THD. This strategy will reduce requirements for animal testing by preventing duplication of testing in mammals and non-mammalian vertebrates and increase the screening capacity to enable more chemicals to be tested for ED properties.
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Richard S, Guyot R, Rey-Millet M, Prieux M, Markossian S, Aubert D, Flamant F. A Pivotal Genetic Program Controlled by Thyroid Hormone during the Maturation of GABAergic Neurons. iScience 2020; 23:100899. [PMID: 32092701 PMCID: PMC7037980 DOI: 10.1016/j.isci.2020.100899] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 12/12/2019] [Accepted: 02/05/2020] [Indexed: 12/23/2022] Open
Abstract
Mammalian brain development critically depends on proper thyroid hormone signaling, via the TRα1 nuclear receptor. The downstream mechanisms by which TRα1 impacts brain development are currently unknown. In order to investigate these mechanisms, we used mouse genetics to induce the expression of a dominant-negative mutation of TRα1 specifically in GABAergic neurons, the main inhibitory neurons in the brain. This triggered post-natal epileptic seizures and a profound impairment of GABAergic neuron maturation in several brain regions. Analysis of the transcriptome and TRα1 cistrome in the striatum allowed us to identify a small set of genes, the transcription of which is upregulated by TRα1 in GABAergic neurons and which probably plays an important role during post-natal maturation of the brain. Thus, our results point to GABAergic neurons as direct targets of thyroid hormone during brain development and suggest that many defects seen in hypothyroid brains may be secondary to GABAergic neuron malfunction.
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Affiliation(s)
- Sabine Richard
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France.
| | - Romain Guyot
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France
| | - Martin Rey-Millet
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France
| | - Margaux Prieux
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France
| | - Suzy Markossian
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France
| | - Denise Aubert
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France
| | - Frédéric Flamant
- Univ Lyon, ENS de Lyon, INRAE, CNRS, Institut de Génomique Fonctionnelle de Lyon, 69364 Lyon, France
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Protective Effects of Euthyroidism Restoration on Mitochondria Function and Quality Control in Cardiac Pathophysiology. Int J Mol Sci 2019; 20:ijms20143377. [PMID: 31295805 PMCID: PMC6678270 DOI: 10.3390/ijms20143377] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/05/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial dysfunctions are major contributors to heart disease onset and progression. Under ischemic injuries or cardiac overload, mitochondrial-derived oxidative stress, Ca2+ dis-homeostasis, and inflammation initiate cross-talking vicious cycles leading to defects of mitochondrial DNA, lipids, and proteins, concurrently resulting in fatal energy crisis and cell loss. Blunting such noxious stimuli and preserving mitochondrial homeostasis are essential to cell survival. In this context, mitochondrial quality control (MQC) represents an expanding research topic and therapeutic target in the field of cardiac physiology. MQC is a multi-tier surveillance system operating at the protein, organelle, and cell level to repair or eliminate damaged mitochondrial components and replace them by biogenesis. Novel evidence highlights the critical role of thyroid hormones (TH) in regulating multiple aspects of MQC, resulting in increased organelle turnover, improved mitochondrial bioenergetics, and the retention of cell function. In the present review, these emerging protective effects are discussed in the context of cardiac ischemia-reperfusion (IR) and heart failure, focusing on MQC as a strategy to blunt the propagation of connected dangerous signaling cascades and limit adverse remodeling. A better understanding of such TH-dependent signaling could provide insights into the development of mitochondria-targeted treatments in patients with cardiac disease.
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Wang Y, Han J, Chen X, Zeng X, Wang Y, Dong J, Chen J. Maternal iodine supplementation improves motor coordination in offspring by modulating the mGluR1 signaling pathway in mild iodine deficiency-induced hypothyroxinemia rats. J Nutr Biochem 2018; 58:80-89. [DOI: 10.1016/j.jnutbio.2018.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/17/2018] [Accepted: 04/22/2018] [Indexed: 02/02/2023]
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Richard S, Flamant F. Regulation of T3 Availability in the Developing Brain: The Mouse Genetics Contribution. Front Endocrinol (Lausanne) 2018; 9:265. [PMID: 29892264 PMCID: PMC5985302 DOI: 10.3389/fendo.2018.00265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/07/2018] [Indexed: 12/11/2022] Open
Abstract
Alterations in maternal thyroid physiology may have deleterious consequences on the development of the fetal brain, but the underlying mechanisms remain elusive, hampering the development of appropriate therapeutic strategies. The present review sums up the contribution of genetically modified mouse models to this field. In particular, knocking out genes involved in thyroid hormone (TH) deiodination, transport, and storage has significantly improved the picture that we have of the economy of TH in the fetal brain and the underlying genetic program. These data pave the way for future studies to bridge the gap in knowledge between thyroid physiology and brain development.
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Frau C, Godart M, Plateroti M. Thyroid hormone regulation of intestinal epithelial stem cell biology. Mol Cell Endocrinol 2017; 459:90-97. [PMID: 28288904 DOI: 10.1016/j.mce.2017.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 01/08/2023]
Abstract
The gastrointestinal tract is a well-characterized target of thyroid hormones and thyroid hormone nuclear receptors TRs, as extensively described in the literature. The paradigm is its important remodelling in amphibians during thyroid hormone-dependent metamorphosis. Interestingly, several studies have described the conservation of this hormonal signal during intestinal development in mammals. Additional data suggested that it may also play a role in intestinal homeostasis, stem cell physiology and progenitor commitment as well as in tumour development. It is worth underlining that in the mammalian intestine the functionality of the TRα1 receptor is coordinated and integrated with other signalling pathways, such as Wnt and Notch, specifically at the level of stem/progenitor cell populations. Here, we summarize these data and concepts and discuss this new role for thyroid hormones and the TRα1 receptor in the biology of intestinal epithelial precursor cells.
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Affiliation(s)
- Carla Frau
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR5286, Université de Lyon, Université Lyon 1, Centre Léon Bérard, Département de La Recherche, 69000 Lyon, France
| | - Matthias Godart
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR5286, Université de Lyon, Université Lyon 1, Centre Léon Bérard, Département de La Recherche, 69000 Lyon, France
| | - Michelina Plateroti
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR5286, Université de Lyon, Université Lyon 1, Centre Léon Bérard, Département de La Recherche, 69000 Lyon, France.
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Richard S, Aguilera N, Thévenet M, Dkhissi-Benyahya O, Flamant F. Neuronal expression of a thyroid hormone receptor α mutation alters mouse behaviour. Behav Brain Res 2016; 321:18-27. [PMID: 28011173 DOI: 10.1016/j.bbr.2016.12.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 12/14/2016] [Accepted: 12/19/2016] [Indexed: 02/06/2023]
Abstract
In humans, alterations in thyroid hormone signalling are associated with mood and anxiety disorders, but the neural mechanisms underlying such association are poorly understood. The present study investigates the involvement of neuronal thyroid hormone receptor α (TRα) in anxiety, using mouse genetics and Cre/loxP technology to specifically alter TRα signalling in neurons. We evaluated the behaviour of mice expressing a dominant negative, neuron-specific mutation of TRα (TRαAMI/Cre3 mice), using the elevated-plus maze, light-dark box and open-field tests. In a first experiment, mice were housed individually, and the behaviour of TRαAMI/Cre3 mice differed significantly from that of control littermates in these 3 tests, suggesting heightened anxiety. In a second experiment, designed to evaluate the robustness of the results with the same 3 tests, mice were housed in groups. In these conditions, the behaviour of TRαAMI/Cre3 mice differed from that of control littermates only in the light-dark box. Thus, TRαAMI/Cre3 mice appear to be more likely to develop anxiety under stressful housing conditions than control mice. These results suggest that in adult mice, thyroid hormone signalling in neurons, via TRα, is involved in the control of anxiety behaviour.
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Affiliation(s)
- S Richard
- IGFL, INRA, Univ. Lyon 1, CNRS, ENS Lyon, 69 007 France.
| | - N Aguilera
- PBES, SFR Biosciences, INSERM, CNRS UMS3444, Univ. Lyon 1, ENS Lyon, France
| | | | - O Dkhissi-Benyahya
- INSERM U846, Stem-cell and Brain Research Institute, Department of Chronobiology, University of Lyon 1, 69003 Lyon, France.
| | - F Flamant
- IGFL, INRA, Univ. Lyon 1, CNRS, ENS Lyon, 69 007 France.
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Ortiga-Carvalho TM, Chiamolera MI, Pazos-Moura CC, Wondisford FE. Hypothalamus-Pituitary-Thyroid Axis. Compr Physiol 2016; 6:1387-428. [PMID: 27347897 DOI: 10.1002/cphy.c150027] [Citation(s) in RCA: 214] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The hypothalamus-pituitary-thyroid (HPT) axis determines the set point of thyroid hormone (TH) production. Hypothalamic thyrotropin-releasing hormone (TRH) stimulates the synthesis and secretion of pituitary thyrotropin (thyroid-stimulating hormone, TSH), which acts at the thyroid to stimulate all steps of TH biosynthesis and secretion. The THs thyroxine (T4) and triiodothyronine (T3) control the secretion of TRH and TSH by negative feedback to maintain physiological levels of the main hormones of the HPT axis. Reduction of circulating TH levels due to primary thyroid failure results in increased TRH and TSH production, whereas the opposite occurs when circulating THs are in excess. Other neural, humoral, and local factors modulate the HPT axis and, in specific situations, determine alterations in the physiological function of the axis. The roles of THs are vital to nervous system development, linear growth, energetic metabolism, and thermogenesis. THs also regulate the hepatic metabolism of nutrients, fluid balance and the cardiovascular system. In cells, TH actions are mediated mainly by nuclear TH receptors (210), which modify gene expression. T3 is the preferred ligand of THR, whereas T4, the serum concentration of which is 100-fold higher than that of T3, undergoes extra-thyroidal conversion to T3. This conversion is catalyzed by 5'-deiodinases (D1 and D2), which are TH-activating enzymes. T4 can also be inactivated by conversion to reverse T3, which has very low affinity for THR, by 5-deiodinase (D3). The regulation of deiodinases, particularly D2, and TH transporters at the cell membrane control T3 availability, which is fundamental for TH action. © 2016 American Physiological Society. Compr Physiol 6:1387-1428, 2016.
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Affiliation(s)
- Tania M Ortiga-Carvalho
- Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | - Maria I Chiamolera
- Department of Medicine, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Carmen C Pazos-Moura
- Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | - Fredic E Wondisford
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
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Fumel B, Froment P, Holzenberger M, Livera G, Monget P, Fouchécourt S. Expression of dominant-negative thyroid hormone receptor alpha1 in Leydig and Sertoli cells demonstrates no additional defect compared with expression in Sertoli cells only. PLoS One 2015; 10:e0119392. [PMID: 25793522 PMCID: PMC4368620 DOI: 10.1371/journal.pone.0119392] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/30/2015] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND In the testis, thyroid hormone (T3) regulates the number of gametes produced through its action on Sertoli cell proliferation. However, the role of T3 in the regulation of steroidogenesis is still controversial. METHODS The TRαAMI knock-in allele allows the generation of transgenic mice expressing a dominant-negative TRα1 (thyroid receptor α1) isoform restricted to specific target cells after Cre-loxP recombination. Here, we introduced this mutant allele in both Sertoli and Leydig cells using a novel aromatase-iCre (ARO-iCre) line that expresses Cre recombinase under control of the human Cyp19(IIa)/aromatase promoter. FINDINGS We showed that loxP recombination induced by this ARO-iCre is restricted to male and female gonads, and is effective in Sertoli and Leydig cells, but not in germ cells. We compared this model with the previous introduction of TRαAMI specifically in Sertoli cells in order to investigate T3 regulation of steroidogenesis. We demonstrated that TRαAMI-ARO males exhibited increased testis weight, increased sperm reserve in adulthood correlated to an increased proliferative index at P3 in vivo, and a loss of T3-response in vitro. Nevertheless, TRαAMI-ARO males showed normal fertility. This phenotype is similar to TRαAMI-SC males. Importantly, plasma testosterone and luteinizing hormone levels, as well as mRNA levels of steroidogenesis enzymes StAR, Cyp11a1 and Cyp17a1 were not affected in TRαAMI-ARO. CONCLUSIONS/SIGNIFICANCE We concluded that the presence of a mutant TRαAMI allele in both Leydig and Sertoli cells does not accentuate the phenotype in comparison with its presence in Sertoli cells only. This suggests that direct T3 regulation of steroidogenesis through TRα1 is moderate in Leydig cells, and that Sertoli cells are the main target of T3 action in the testis.
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Affiliation(s)
- Betty Fumel
- INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- CNRS, UMR7247 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- Université François Rabelais de Tours, F-37041, Tours, France
- IFCE, F-37380, Nouzilly, France
| | - Pascal Froment
- INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- CNRS, UMR7247 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- Université François Rabelais de Tours, F-37041, Tours, France
- IFCE, F-37380, Nouzilly, France
| | - Martin Holzenberger
- INSERM and Sorbonne Universités—UPMC, UMRS 938, Hôpital Saint-Antoine, 75012, Paris, France
| | - Gabriel Livera
- Laboratoire de Développement des Gonades, INSERM U967, CEA/DSV/iRCM/SCSR/LDG, Univ Paris Diderot, Sorbonne Paris Cité, Univ Paris Sud, F-92265, Fontenay-Aux-Roses, France
| | - Philippe Monget
- INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- CNRS, UMR7247 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- Université François Rabelais de Tours, F-37041, Tours, France
- IFCE, F-37380, Nouzilly, France
| | - Sophie Fouchécourt
- INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- CNRS, UMR7247 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
- Université François Rabelais de Tours, F-37041, Tours, France
- IFCE, F-37380, Nouzilly, France
- * E-mail:
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