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Duarte-Ribeiro E, Rosas-Puchuri U, Friedman M, Woodruff GC, Hughes LC, Carpenter KE, White WT, Pogonoski JJ, Westneat M, Diaz de Astarloa JM, Williams JT, Santos MD, Domínguez-Domínguez O, Ortí G, Arcila D, Betancur-R R. Phylogenomic and comparative genomic analyses support a single evolutionary origin of flatfish asymmetry. Nat Genet 2024; 56:1069-1072. [PMID: 38802566 DOI: 10.1038/s41588-024-01784-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/25/2024] [Indexed: 05/29/2024]
Affiliation(s)
- Emanuell Duarte-Ribeiro
- School of Biological Sciences, University of Oklahoma, Norman, OK, USA.
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland.
| | | | - Matt Friedman
- Museum of Paleontology, Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Gavin C Woodruff
- School of Biological Sciences, University of Oklahoma, Norman, OK, USA
| | - Lily C Hughes
- North Carolina State University, North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - Kent E Carpenter
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - William T White
- CSIRO Australian National Fish Collection, National Research Collections Australia, Hobart, Tasmania, Australia
| | - John J Pogonoski
- CSIRO Australian National Fish Collection, National Research Collections Australia, Hobart, Tasmania, Australia
| | - Mark Westneat
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
| | - Juan Martin Diaz de Astarloa
- Instituto de Investigaciones Marinas y Costeras, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Jeffrey T Williams
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Mudjekeewis D Santos
- National Fisheries Research and Development Institute, Department of Agriculture, Quezon City, Philippines
| | | | - Guillermo Ortí
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Dahiana Arcila
- School of Biological Sciences, University of Oklahoma, Norman, OK, USA
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Ricardo Betancur-R
- School of Biological Sciences, University of Oklahoma, Norman, OK, USA.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
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2
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Chang J, Xu Y, Fu Y, Liu J, Jiang D, Pan J, Ouyang H, Liu W, Xu J, Tian Y, Huang Y, Ruan J, Shen X. The dynamic landscape of chromatin accessibility and active regulatory elements in the mediobasal hypothalamus influences the seasonal activation of the reproductive axis in the male quail under long light exposure. BMC Genomics 2024; 25:197. [PMID: 38373887 PMCID: PMC10877898 DOI: 10.1186/s12864-024-10097-5] [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: 09/18/2023] [Accepted: 02/07/2024] [Indexed: 02/21/2024] Open
Abstract
BACKGROUND In cold and temperate zones, seasonal reproduction plays a crucial role in the survival and reproductive success of species. The photoperiod influences reproductive processes in seasonal breeders through the hypothalamic-pituitary-gonadal (HPG) axis, in which the mediobasal hypothalamus (MBH) serves as the central region responsible for transmitting light information to the endocrine system. However, the cis-regulatory elements and the transcriptional activation mechanisms related to seasonal activation of the reproductive axis in MBH remain largely unclear. In this study, an artificial photoperiod program was used to induce the HPG axis activation in male quails, and we compared changes in chromatin accessibility changes during the seasonal activation of the HPG axis. RESULTS Alterations in chromatin accessibility occurred in the mediobasal hypothalamus (MBH) and stabilized at LD7 during the activation of the HPG axis. Most open chromatin regions (OCRs) are enriched mainly in introns and distal intergenic regions. The differentially accessible regions (DARs) showed enrichment of binding motifs of the RFX, NKX, and MEF family of transcription factors that gained-loss accessibility under long-day conditions, while the binding motifs of the nuclear receptor (NR) superfamily and BZIP family gained-open accessibility. Retinoic acid signaling and GTPase-mediated signal transduction are involved in adaptation to long days and maintenance of the HPG axis activation. According to our footprint analysis, three clock-output genes (TEF, DBP, and HLF) and the THRA were the first responders to long days in LD3. THRB, NR3C2, AR, and NR3C1 are the key players associated with the initiation and maintenance of the activation of the HPG axis, which appeared at LD7 and tended to be stable under long-day conditions. By integrating chromatin and the transcriptome, three genes (DIO2, SLC16A2, and PDE6H) involved in thyroid hormone signaling showed differential chromatin accessibility and expression levels during the seasonal activation of the HPG axis. TRPA1, a target of THRB identified by DAP-seq, was sensitive to photoactivation and exhibited differential expression levels between short- and long-day conditions. CONCLUSION Our data suggest that trans effects were the main factors affecting gene expression during the seasonal activation of the HPG axis. This study could lead to further research on the seasonal reproductive behavior of birds, particularly the role of MBH in controlling seasonal reproductive behavior.
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Affiliation(s)
- Jianye Chang
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Yanglong Xu
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yuting Fu
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jiaxin Liu
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Danli Jiang
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jianqiu Pan
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Hongjia Ouyang
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Wenjun Liu
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jin Xu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510642, China
| | - Yunbo Tian
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yunmao Huang
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
| | - Jue Ruan
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China.
| | - Xu Shen
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
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3
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Katarzyńska-Banasik D, Kowalik K, Sechman A. Influence of silver nanoparticles on mRNA expression of thyroid hormone-related genes in the thyroid gland and liver of laying hens. Domest Anim Endocrinol 2024; 86:106820. [PMID: 37918317 DOI: 10.1016/j.domaniend.2023.106820] [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: 06/23/2023] [Revised: 08/18/2023] [Accepted: 09/28/2023] [Indexed: 11/04/2023]
Abstract
The widespread use of silver nanoparticles (AgNPs) in consumer products and animal husbandry raises the need to study their impact on living organisms. This study was conducted on Hy-Line Brown hens at the age of 25 weeks with an average weight of 1.58 kg. Hens for 2 weeks received a solution of 50 nm AgNPs at a concentration of 100 pm (experimental group; n = 6) or a solution in which the nanoparticles were suspended (control group; n = 6). Thyroid hormones (thyroxine - T4, triiodothyronine - T3) were evaluated in the blood plasma and expression profiles of genes involved in thyroid hormone (TH) synthesis (TSHR, NIS, TPO, TG), metabolism (DIO1, DIO2, DIO3) and transport (MCT8, MCT10, LAT1) were determined in the chicken thyroid gland. Furthermore, iodothyronine deiodinase, TH transporter and TH receptor (THRA, THRB) mRNA expressions were evaluated in the livers isolated from the same chickens. AgNPs did not affect serum T4 levels but elevated serum T3 concentration. The results showed that AgNPs increased DIO3 mRNA in the thyroid gland. In turn, in the liver AgNPs administration significantly upregulated DIO2 and downregulated MCT10 mRNA levels. These results indicate that exposure to AgNPs leads to a tissue-specific alternative expression of genes engaged in TH metabolism. Moreover, the mRNA expression of DIO2 in the liver showed a positive correlation with plasma T3 levels. In conclusion, AgNPs may have an impact on TH metabolism by affecting deiodinases and TH transporter MCT10 mRNA expression.
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Affiliation(s)
- D Katarzyńska-Banasik
- Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 21, 31-120, Krakow, Poland.
| | - K Kowalik
- Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 21, 31-120, Krakow, Poland
| | - A Sechman
- Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 21, 31-120, Krakow, Poland
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4
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Jing L, Zhang Q. Intrathyroidal feedforward and feedback network regulating thyroid hormone synthesis and secretion. Front Endocrinol (Lausanne) 2022; 13:992883. [PMID: 36187113 PMCID: PMC9519864 DOI: 10.3389/fendo.2022.992883] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Thyroid hormones (THs), including T4 and T3, are produced and released by the thyroid gland under the stimulation of thyroid-stimulating hormone (TSH). The homeostasis of THs is regulated via the coordination of the hypothalamic-pituitary-thyroid axis, plasma binding proteins, and local metabolism in tissues. TH synthesis and secretion in the thyrocytes-containing thyroid follicles are exquisitely regulated by an elaborate molecular network comprising enzymes, transporters, signal transduction machineries, and transcription factors. In this article, we synthesized the relevant literature, organized and dissected the complex intrathyroidal regulatory network into structures amenable to functional interpretation and systems-level modeling. Multiple intertwined feedforward and feedback motifs were identified and described, centering around the transcriptional and posttranslational regulations involved in TH synthesis and secretion, including those underpinning the Wolff-Chaikoff and Plummer effects and thyroglobulin-mediated feedback regulation. A more thorough characterization of the intrathyroidal network from a systems biology perspective, including its topology, constituent network motifs, and nonlinear quantitative properties, can help us to better understand and predict the thyroidal dynamics in response to physiological signals, therapeutic interventions, and environmental disruptions.
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Affiliation(s)
- Li Jing
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing, China
| | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
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5
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Kowalik K, Sechman A. In vitro effects of polychlorinated biphenyls and their hydroxylated metabolites on the synthesis and metabolism of iodothyronines in the chicken (Gallus domesticus) thyroid gland. Gen Comp Endocrinol 2022; 318:113989. [PMID: 35151725 DOI: 10.1016/j.ygcen.2022.113989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 11/17/2022]
Abstract
To assess the effect of polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (OH-PCBs) on thyroid hormone [TH: thyroxine (T4) and triiodothyronine (T3)] secretion, the concentrations of iodothyronine deiodinases (DIO1, DIO2, DIO3), and mRNA expression of genes involved in TH synthesis (TSHR, NIS, TPO, TG), metabolism (DIO1, DIO2, DIO3), and transport (OATP1C1, MCT8, MCT10, LAT1), chicken thyroid explants were incubated in medium supplemented with TSH (250 mU/ml), PCB118, PCB153, 4-OH-PCB107, and 3-OH-PCB153 (0.5 × 10-8 M), and TSH together with each PCB and OH-PCB. The results of the in vitro experiment revealed that, except for 4-OH-PCB107, all applied PCBs and OH-PCBs inhibited basal and TSH-stimulated T4 secretion. Moreover, they increased basal and reduced TSH-stimulated T3 secretion. PCBs and OH-PCBs decreased the TSH-stimulated TSHR expression. Following PCB and OH-PCB exposure, significant changes in mRNA expression of NIS, TPO, and TG were observed. PCBs and OH-PCBs affected DIO1 and DIO3 transcript levels and protein abundances of each DIO. Furthermore, PCB-dependent effects on OATP1C1, MCT8, and MCT10 mRNA expression were found. In conclusion, both PCB118 and PCB153 and their OH-PCBs affect TH synthesis and deiodination processes in the chicken thyroid gland and influence TH transport across the thyrocyte membrane. In addition, the effects of PCBs and OH-PCBs depended mainly on the type of PCB congener and the exposure time. These results indicate that not only parental PCBs but also OH-PCBs are hazardous for the thyroid gland and may disrupt its endocrine function. Further studies are necessary to explain a mechanism of PCB and OH-PCB action in the avian thyroid gland.
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Affiliation(s)
- Kinga Kowalik
- Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland.
| | - Andrzej Sechman
- Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland
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Sabatino L, Vassalle C, Del Seppia C, Iervasi G. Deiodinases and the Three Types of Thyroid Hormone Deiodination Reactions. Endocrinol Metab (Seoul) 2021; 36:952-964. [PMID: 34674502 PMCID: PMC8566136 DOI: 10.3803/enm.2021.1198] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/15/2021] [Indexed: 12/27/2022] Open
Abstract
Thyroid hormone (TH) signaling is strictly regulated by iodothyronine deiodinase activity, which both preserves the circulating levels of the biologically active triiodothyronine (T3) and regulates TH homeostasis at the local level, in a cell- and time-dependent manner. Three deiodinases have been identified-namely iodothyronine deiodinase 1 (DIO1), DIO2, and DIO3-that differ in their catalytic properties and tissue distribution. The deiodinases represent a dynamic system that changes in the different stages of life according to their functions and roles in various cell types and tissues. Deiodinase activity at the tissue level permits cell-targeted fine regulation of TH homeostasis, mediating the activation (DIO1 and DIO2) and inactivation (DIO3) of THs. Deiodinase homeostasis is the driving force that leads T3-target cells towards customized TH signaling, which takes into account both the hormonal circulating levels and the tissue-specific response. This review analyzes the complex role of deiodinases in physiological and pathological contexts, exploring new challenges and opportunities deriving from a deeper knowledge of the dynamics underlying their roles and functions.
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Affiliation(s)
- Laura Sabatino
- Institute of Clinical Physiology, National Research Council of Italy (CNR), Pisa,
Italy
| | | | - Cristina Del Seppia
- Institute of Clinical Physiology, National Research Council of Italy (CNR), Pisa,
Italy
| | - Giorgio Iervasi
- Institute of Clinical Physiology, National Research Council of Italy (CNR), Pisa,
Italy
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7
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Marty S, Beekhuijzen M, Charlton A, Hallmark N, Hannas BR, Jacobi S, Melching-Kollmuss S, Sauer UG, Sheets LP, Strauss V, Urbisch D, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny - part II: how can key events of relevant adverse outcome pathways be addressed in toxicological assessments? Crit Rev Toxicol 2021; 51:328-358. [PMID: 34074207 DOI: 10.1080/10408444.2021.1910625] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The current understanding of thyroid-related adverse outcome pathways (AOPs) with adverse neurodevelopmental outcomes in mammals has been reviewed. This served to establish if standard rodent toxicity test methods and in vitro assays allow identifying thyroid-related modes-of-action potentially leading to adverse neurodevelopmental outcomes, and the human relevance of effects - in line with the European Commission's Endocrine Disruptor Criteria. The underlying hypothesis is that an understanding of the key events of relevant AOPs provides insight into differences in incidence, magnitude, or species sensitivity of adverse outcomes. The rodent studies include measurements of serum thyroid hormones, thyroid gland pathology and neurodevelopmental assessments, but do not directly inform on specific modes-of-action. Opportunities to address additional non-routine parameters reflecting critical events of AOPs in toxicological assessments are presented. These parameters appear relevant to support the identification of specific thyroid-related modes-of-action, provided that prevailing technical limitations are overcome. Current understanding of quantitative key event relationships is often weak, but would be needed to determine if the triggering of a molecular initiating event will ultimately result in an adverse outcome. Also, significant species differences in all processes related to thyroid hormone signalling are evident, but the biological implications thereof (including human relevance) are often unknown. In conclusion, careful consideration of the measurement (e.g. timing, method) and interpretation of additional non-routine parameters is warranted. These findings will be used in a subsequent paper to propose a testing strategy to identify if a substance may elicit maternal thyroid hormone imbalance and potentially also neurodevelopmental effects in the progeny.
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Affiliation(s)
- Sue Marty
- The Dow Chemical Company, Midland, MI, USA
| | | | | | | | | | | | | | - Ursula G Sauer
- Scientific Consultancy - Animal Welfare, Neubiberg, Germany
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8
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Xia SF, Jiang YY, Qiu YY, Huang W, Wang J. Role of diets and exercise in ameliorating obesity-related hepatic steatosis: Insights at the microRNA-dependent thyroid hormone synthesis and action. Life Sci 2020; 242:117182. [PMID: 31863770 DOI: 10.1016/j.lfs.2019.117182] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/10/2019] [Accepted: 12/14/2019] [Indexed: 12/16/2022]
Abstract
AIMS The present study was designed to compare the effects of a low-fat diet (LF), calorie restriction (CR), quercetin (Que) and exercise (Ex) on hepatic steatosis in a high-fat (HF) diet-induced obesity prone (OP) model in the perspective of microRNA (miR)-dependent thyroid hormone (TH) synthesis and action. MAIN METHODS Male C57BL/6J mice were administered a HF diet for 10 weeks to induce OP phenotype and then divided into 5 groups, HF diet (OP-HF), LF diet (OP-LF), 70% CR (OP-CR), 0.05% Que (OP-Que) and a treadmill exercise regimen (OP-Ex); one additional group fed LF diet served as control (LF). 7 weeks later, serum indexes, metabolic alterations, redox status and histological appearance in the thyroid and liver, and TH related miRs with their targets expressions were determined. KEY FINDINGS No significance on T3 levels was observed among the six groups. LF, CR, Que and Ex significantly ameliorated HF-induced hepatic steatosis to varying degrees, inhibited T4 production via differentially elevating miR-339, miR-383 and miR-146b to decrease NIS expression and regulating miR-200a/Nrf2 to maintain redox status in the thyroid. Furthermore, these four interventions differentially and significantly decreased miR-383 and miR-146b to elevate TRb and DIO1 expression, and subsequent TH responsive lipid metabolism genes regulation. Among them, the effects of CR on hepatic steatosis were the most prominent. SIGNIFICANCE Our data indicated that amelioration of hepatic steatosis by LF, CR, Que and Ex resulted in many shared, but also many differential changes in the miR-dependent TH production and action.
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Affiliation(s)
- Shu-Fang Xia
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Yu-Yu Jiang
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Yu-Yu Qiu
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Wei Huang
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Jun Wang
- Department of Rehabilitation, Wuxi 9th Affiliated Hospital of Soochow University, Wuxi, China.
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Liang X, Feng Y, Lin L, Abeysekera IR, Iqbal U, Wang T, Wang Y, Yao X. Thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring. J Trace Elem Med Biol 2018; 47:89-97. [PMID: 29544812 DOI: 10.1016/j.jtemb.2018.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 01/21/2018] [Accepted: 01/31/2018] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Our aim was to investigate thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring. METHODS Depending on their iodide intake, the pregnant rats were randomly divided into three groups: normal iodide intake (NI), 10 times high iodide intake (10 HI) and 100 times high iodide intake (100 HI) groups. Iodine concentration in the urine and maternal milk; iodine content and mitochondrial superoxide production; expression of TRα1, TRβ1, NIS and Dio1 in both the thyroid and mammary glands were all measured. The offspring were exposed to different iodide-containing water (NI, 10 HI and 100 HI) from weaning to postnatal day 180 (PN180). Serum thyroid hormone levels were measured in both maternal rats and their offspring. RESULTS Iodine concentration in the urine and maternal milk, as well as iodine content in the thyroid and mammary glands was significantly increased in both the 10 HI and 100 HI groups (p < .05). In the 100 HI group of maternal rats, low FT3 levels, high FT4, TPOAb and TgAb levels were detected. In addition, an increased mitochondrial superoxide production and decreased expression of TRα1, TRβ1, NIS and Dio1 in the thyroid and mammary glands was found (p < .05). A positive staining of CD4+ that co-localized with TRβ1 in the infiltrated cells within the thyroid follicles was observed. At PN180 in the offspring, the FT3 and FT4 levels showed a significant decrease, while the levels of serum TSH, TPOAb and TgAb were significantly increased in both 10 HI and 100 HI groups (p < .05). CONCLUSION In maternal rats, although normal thyroid function can be maintained following 10 HI, thyroiditis can be induced following 100 HI on lactation days 7, 14, and 21. In the offspring at PN180, hypothyroidism complicated with thyroiditis can occur in both the 10 HI and 100 HI groups.
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Affiliation(s)
- Xue Liang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Yanni Feng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Laixiang Lin
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China.
| | - Iruni Roshanie Abeysekera
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Umar Iqbal
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Tingting Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Ying Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Xiaomei Yao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
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Yamauchi I, Sakane Y, Yamashita T, Hirota K, Ueda Y, Kanai Y, Yamashita Y, Kondo E, Fujii T, Taura D, Sone M, Yasoda A, Inagaki N. Effects of growth hormone on thyroid function are mediated by type 2 iodothyronine deiodinase in humans. Endocrine 2018; 59:353-363. [PMID: 29274063 DOI: 10.1007/s12020-017-1495-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/05/2017] [Indexed: 11/30/2022]
Abstract
PURPOSE Growth hormone (GH) therapy in adults alters thyroid function, and acromegaly often involves thyroid disease. The present study aimed to elucidate roles and mechanisms of GH in regulating thyroid function. METHODS We performed two retrospective observational studies, which focused on consecutive patients with severe adult GH deficiency who received recombinant human GH (rhGH) therapy (n = 20) and consecutive patients with acromegaly who underwent transsphenoidal surgery (TSS) (n = 25). In both studies, serum free triiodothyronine (fT3), free thyroxine (fT4), and fT3/fT4 ratio were examined before and after the interventions. We subsequently administered GH to four human cell lines (HepG2, TSA201, MCF7, and HTC/C3) in vitro, and examined changes in mRNA levels of iodothyronine deiodinases (D1, D2, and D3). RESULTS Median serum fT3 level significantly increased after rhGH therapy from 2.38 to 2.78 pg/mL (p < 0.001), and fT4 decreased from 1.115 to 1.065 ng/dL (p = 0.081). TSS significantly decreased median serum fT3 from 3.03 to 2.53 pg/mL (p < 0.001), and increased fT4 from 1.230 to 1.370 ng/dL (p < 0.001). In vitro, GH significantly increased D2 expression at the mRNA level in HTC/C3 cells (p < 0.01), as well as D2 protein and its activity. CONCLUSIONS GH increased serum fT3 level and decreased serum fT4 level in humans. Our results suggest that its mechanism involves D2 upregulation. Considering this GH effect on thyroid hormone metabolism, data on thyroid function could be useful in the management of GH deficiency and acromegaly.
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Affiliation(s)
- Ichiro Yamauchi
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Yoriko Sakane
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
- Preemptive Medicine and Lifestyle Disease Research Center, Kyoto University Hospital, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Takafumi Yamashita
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Keisho Hirota
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Yohei Ueda
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Yugo Kanai
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Yui Yamashita
- Department of Internal Medicine, Otsu Red Cross Hospital, 1-1-35 Nagara, Otsu, Shiga, 520-8511, Japan
| | - Eri Kondo
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Toshihito Fujii
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Daisuke Taura
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Masakatsu Sone
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Akihiro Yasoda
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
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11
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Carvalho DP, Dupuy C. Thyroid hormone biosynthesis and release. Mol Cell Endocrinol 2017; 458:6-15. [PMID: 28153798 DOI: 10.1016/j.mce.2017.01.038] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 01/07/2017] [Accepted: 01/23/2017] [Indexed: 12/31/2022]
Abstract
Thyroid hormones (TH) 3,5,3',5'- tetraiodothyronine or thyroxine (T4) and 3,5,3'- triiodothyronine (T3) contain iodine atoms as part of their structure, and their synthesis occur in the unique structures called thyroid follicles. Iodide reaches thyroid cells through the bloodstream that supplies the basolateral plasma membrane of thyrocytes, where it is avidly taken up through the sodium/iodide symporter (NIS). Thyrocytes are also specialized in the secretion of the high molecular weight protein thyroglobulin (TG) in the follicular lumen. The iodination of the tyrosyl residues of TG preceeds TH biosynthesis, which depends on the interaction of iodide, TG, hydrogen peroxide (H2O2) and thyroid peroxidase (TPO) at the apical plasma membrane of thyrocytes. Thyroid hormone biosynthesis is under the tonic control of thyrotropin (TSH), while the iodide recycling ability is very important for normal thyroid function. We discuss herein the biochemical aspects of TH biosynthesis and release, highlighting the novel molecules involved in the process.
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Affiliation(s)
- Denise P Carvalho
- Biophysics Institute of Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Corinne Dupuy
- Université Paris-Saclay, Orsay, France; UMR 8200 CNRS, Villejuif, France; Institut de Cancérologie Gustave Roussy, Villejuif, Ile-de-France, France
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12
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Ikegami K, Yoshimura T. The hypothalamic-pituitary-thyroid axis and biological rhythms: The discovery of TSH's unexpected role using animal models. Best Pract Res Clin Endocrinol Metab 2017; 31:475-485. [PMID: 29223282 DOI: 10.1016/j.beem.2017.09.002] [Citation(s) in RCA: 19] [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: 11/23/2022]
Abstract
Thyroid hormones (TH) are important for development, growth, and metabolism. It is also clear that the synthesis and secretion of TH are regulated by the hypothalamic-pituitary-thyroid (HPT) axis. Animal models have helped advance our understanding of the roles and regulatory mechanisms of TH. The animals' bodies develop through coordinated timing of cell division and differentiation. Studies of frog metamorphosis led to the discovery of TH and their role in development. However, to adapt to rhythmic environmental changes, animals also developed various endocrine rhythms. Studies of rodents clarified the neural and molecular mechanisms underlying the circadian regulation of the HPT axis. Moreover, birds have a sophisticated seasonal adaptation mechanism, and recent studies of quail revealed unexpected roles for thyroid-stimulating hormone (TSH) and TH in the seasonal regulation of reproduction. Interestingly, this mechanism is conserved in mammals. Thus, we review how animal studies have shaped our general understanding of the HPT axis in relation to biological rhythms.
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Affiliation(s)
- Keisuke Ikegami
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Takashi Yoshimura
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Division of Seasonal Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan.
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13
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Malt EA, Juhasz K, Malt UF, Naumann T. A Role for the Transcription Factor Nk2 Homeobox 1 in Schizophrenia: Convergent Evidence from Animal and Human Studies. Front Behav Neurosci 2016; 10:59. [PMID: 27064909 PMCID: PMC4811959 DOI: 10.3389/fnbeh.2016.00059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/11/2016] [Indexed: 12/22/2022] Open
Abstract
Schizophrenia is a highly heritable disorder with diverse mental and somatic symptoms. The molecular mechanisms leading from genes to disease pathology in schizophrenia remain largely unknown. Genome-wide association studies (GWASs) have shown that common single-nucleotide polymorphisms associated with specific diseases are enriched in the recognition sequences of transcription factors that regulate physiological processes relevant to the disease. We have used a “bottom-up” approach and tracked a developmental trajectory from embryology to physiological processes and behavior and recognized that the transcription factor NK2 homeobox 1 (NKX2-1) possesses properties of particular interest for schizophrenia. NKX2-1 is selectively expressed from prenatal development to adulthood in the brain, thyroid gland, parathyroid gland, lungs, skin, and enteric ganglia, and has key functions at the interface of the brain, the endocrine-, and the immune system. In the developing brain, NKX2-1-expressing progenitor cells differentiate into distinct subclasses of forebrain GABAergic and cholinergic neurons, astrocytes, and oligodendrocytes. The transcription factor is highly expressed in mature limbic circuits related to context-dependent goal-directed patterns of behavior, social interaction and reproduction, fear responses, responses to light, and other homeostatic processes. It is essential for development and mature function of the thyroid gland and the respiratory system, and is involved in calcium metabolism and immune responses. NKX2-1 interacts with a number of genes identified as susceptibility genes for schizophrenia. We suggest that NKX2-1 may lie at the core of several dose dependent pathways that are dysregulated in schizophrenia. We correlate the symptoms seen in schizophrenia with the temporal and spatial activities of NKX2-1 in order to highlight promising future research areas.
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Affiliation(s)
- Eva A Malt
- Department of Adult Habilitation, Akershus University HospitalLørenskog, Norway; Institute of Clinical Medicine, Ahus Campus University of OsloOslo, Norway
| | - Katalin Juhasz
- Department of Adult Habilitation, Akershus University Hospital Lørenskog, Norway
| | - Ulrik F Malt
- Institute of Clinical Medicine, University of OsloOslo, Norway; Department of Research and Education, Institution of Oslo University HospitalOslo, Norway
| | - Thomas Naumann
- Centre of Anatomy, Institute of Cell Biology and Neurobiology, Charite Universitätsmedizin Berlin Berlin, Germany
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14
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Mohácsik P, Füzesi T, Doleschall M, Szilvásy-Szabó A, Vancamp P, Hadadi É, Darras VM, Fekete C, Gereben B. Increased Thyroid Hormone Activation Accompanies the Formation of Thyroid Hormone-Dependent Negative Feedback in Developing Chicken Hypothalamus. Endocrinology 2016; 157:1211-21. [PMID: 26779746 DOI: 10.1210/en.2015-1496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The hypothalamic-pituitary-thyroid axis is governed by hypophysiotropic TRH-synthesizing neurons located in the hypothalamic paraventricular nucleus under control of the negative feedback of thyroid hormones. The mechanisms underlying the ontogeny of this phenomenon are poorly understood. We aimed to determine the onset of thyroid hormone-mediated hypothalamic-negative feedback and studied how local hypothalamic metabolism of thyroid hormones could contribute to this process in developing chicken. In situ hybridization revealed that whereas exogenous T4 did not induce a statistically significant inhibition of TRH expression in the paraventricular nucleus at embryonic day (E)19, T4 treatment was effective at 2 days after hatching (P2). In contrast, TRH expression responded to T3 treatment in both age groups. TSHβ mRNA expression in the pituitary responded to T4 in a similar age-dependent manner. Type 2 deiodinase (D2) was expressed from E13 in tanycytes of the mediobasal hypothalamus, and its activity increased between E15 and P2 both in the mediobasal hypothalamus and in tanycyte-lacking hypothalamic regions. Nkx2.1 was coexpressed with D2 in E13 and P2 tanycytes and transcription of the cdio2 gene responded to Nkx2.1 in U87 glioma cells, indicating its potential role in the developmental regulation of D2 activity. The T3-degrading D3 enzyme was also detected in tanycytes, but its level was not markedly changed before and after the period of negative feedback acquisition. These findings suggest that increasing the D2-mediated T3 generation during E18-P2 could provide the sufficient local T3 concentration required for the onset of T3-dependent negative feedback in the developing chicken hypothalamus.
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Affiliation(s)
- P Mohácsik
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - T Füzesi
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - M Doleschall
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - A Szilvásy-Szabó
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - P Vancamp
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - É Hadadi
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - V M Darras
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - C Fekete
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - B Gereben
- Department of Endocrine Neurobiology (P.M., T.F., M.D., A.S.S., É.H., C.F., B.G.), Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary; János Szentágothai PhD School of Neurosciences (P.M., A.S.S.), Semmelweis University, H-1085 Budapest, Hungary; Laboratory of Comparative Endocrinology (P.V., V.M.D.), Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3001 Leuven, Belgium; and Department of Medicine (C.F.), Division of Endocrinology, Diabetes, and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
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15
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Gereben B, McAninch EA, Ribeiro MO, Bianco AC. Scope and limitations of iodothyronine deiodinases in hypothyroidism. Nat Rev Endocrinol 2015; 11:642-652. [PMID: 26416219 PMCID: PMC5003781 DOI: 10.1038/nrendo.2015.155] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The coordinated expression and activity of the iodothyronine deiodinases regulate thyroid hormone levels in hypothyroidism. Once heralded as the pathway underpinning adequate thyroid-hormone replacement therapy with levothyroxine, the role of these enzymes has come into question as they have been implicated in both an inability to normalize serum levels of tri-iodothyronine (T3) and the incomplete resolution of hypothyroid symptoms. These observations, some of which were validated in animal models of levothyroxine monotherapy, challenge the paradigm that tissue levels of T3 and thyroid-hormone signalling can be fully restored by administration of levothyroxine alone. The low serum levels of T3 observed among patients receiving levothyroxine monotherapy occur as a consequence of type 2 iodothyronine deiodinase (DIO2) in the hypothalamus being fairly insensitive to ubiquitination. In addition, residual symptoms of hypothyroidism have been linked to a prevalent polymorphism in the DIO2 gene that might be a risk factor for neurodegenerative disease. Here, we discuss how these novel findings underscore the clinical importance of iodothyronine deiodinases in hypothyroidism and how an improved understanding of these enzymes might translate to therapeutic advances in the care of millions of patients with this condition.
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Affiliation(s)
- Balázs Gereben
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony Street 43, Budapest H-1083, Hungary
| | - Elizabeth A McAninch
- Division of Endocrinology and Metabolism, Rush University Medical Center, 212 Cohn Building, 1735 West Harrison Street, Chicago, IL 60612, USA
| | - Miriam O Ribeiro
- Developmental Disorders Program, Center for Biological and Health Science, Mackenzie Presbyterian University, Rua da Consolação 930, Building 16, São Paulo, SP 01302, Brazil
| | - Antonio C Bianco
- Division of Endocrinology and Metabolism, Rush University Medical Center, 212 Cohn Building, 1735 West Harrison Street, Chicago, IL 60612, USA
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16
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Lavado-Autric R, Calvo RM, de Mena RM, de Escobar GM, Obregon MJ. Deiodinase activities in thyroids and tissues of iodine-deficient female rats. Endocrinology 2013; 154:529-36. [PMID: 23142811 DOI: 10.1210/en.2012-1727] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Severe iodine deficiency is characterized by goiter, preferential synthesis, and secretion of T(3) in thyroids, hypothyroxinemia in plasma and tissues, normal or low plasma T(3), and slightly increased plasma TSH. We studied changes in deiodinase activities and mRNA in several tissues of rats maintained on low-iodine diets (LIDs) or LIDs supplemented with iodine (LID+I). T(4) and T(3) concentrations decreased in plasma, tissues, and thyroids of LID rats, and T(4) decreased more than T(3) (50%). The highest type 1 iodothyronine deiodinase (D1) activities were found in the thyroid, kidney, and the liver; pituitary, lung, and ovary had lower D1 activities; but the lowest levels were found in the heart and skeletal muscle. D1 activity decreased in all tissues of LID rats (10-40% of LID+I rats), except for ovary and thyroids, which D1 activity increased 2.5-fold. Maximal type 2 iodothyronine deiodinase (D2) activities were found in thyroid, brown adipose tissue, and pituitary, increasing 6.5-fold in thyroids of LID rats and about 20-fold in the whole gland. D2 always increased in response to LID, and maximal increases were found in the cerebral cortex (19-fold), thyroid, brown adipose tissue, and pituitary (6-fold). Lower D2 activities were found in the ovary, heart, and adrenal gland, which increased in LID. Type 3 iodothyronine deiodinase activity was undetectable. Thyroidal Dio1 and Dio2 mRNA increased in the LID rats, and Dio1 decreased in the lung, with no changes in mRNA expression in other tissues. Our data indicate that LID induces changes in deiodinase activities, especially in the thyroid, to counteract the low T(4) synthesis and secretion, contributing to maintain the local T(3) concentrations in the tissues with D2 activity.
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17
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Canettieri G, Santaguida MG, Antonucci L, Della Guardia M, Franchi A, Coni S, Gulino A, Centanni M. CCAAT/enhancer-binding proteins are key regulators of human type two deiodinase expression in a placenta cell line. Endocrinology 2012; 153:4030-8. [PMID: 22689263 PMCID: PMC3404352 DOI: 10.1210/en.2011-2113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 05/16/2012] [Indexed: 11/19/2022]
Abstract
An appropriate concentration of intracellular T(3) is a critical determinant of placenta development and function and is mainly controlled by the activity of type II deiodinase (D2). The levels of this enzyme are finely regulated in different tissues by coordinated transcriptional mechanisms, which rely on dedicated promoter sequences (e.g. cAMP response element and TATA elements) that impart inducibility and tissue specificity to Dio2 mRNA expression. Here we show that CCAAT enhancer-binding proteins α and β (C/EBPα and C/EBPβ) promote Dio2 expression in the trophoblastic cell line JEG3 through a conserved CCAAT element, which is a novel key component of the Dio2 promoter code that confers tissue-specific expression of D2 in these cells. Increased C/EBPs levels potently induce Dio2 transcription, whereas their ablation results in loss of Dio2 mRNA. By measuring the activity of several deletion and point mutant promoter constructs, we have identified the functional CCAAT element responsible for this effect, which is located in close proximity to the most 5' TATA box. Notably, this newly identified sequence is highly conserved throughout the species and binds in vivo and in vitro C/EBP, indicating the relevance of this regulatory mechanism. Together, our results unveil a novel mechanism of regulation of D2 expression in a trophoblastic cell line, which may play a relevant role during placenta development.
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Affiliation(s)
- Gianluca Canettieri
- Laboratory of Molecular Oncology Department of Molecular Medicine, “Sapienza” University of Rome, I-00161 Rome and I-04100 Latina, Italy.
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18
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Casula S, Bianco AC. Thyroid hormone deiodinases and cancer. Front Endocrinol (Lausanne) 2012; 3:74. [PMID: 22675319 PMCID: PMC3365412 DOI: 10.3389/fendo.2012.00074] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/15/2012] [Indexed: 12/24/2022] Open
Abstract
Deiodinases constitute a group of thioredoxin fold-containing selenoenzymes that play an important function in thyroid hormone homeostasis and control of thyroid hormone action. There are three known deiodinases: D1 and D2 activate the pro-hormone thyroxine (T4) to T3, the most active form of thyroid hormone, while D3 inactivates thyroid hormone and terminates T3 action. A number of studies indicate that deiodinase expression is altered in several types of cancers, suggesting that (i) they may represent a useful cancer marker and/or (ii) could play a role in modulating cell proliferation - in different settings thyroid hormone modulates cell proliferation. For example, although D2 is minimally expressed in human and rodent skeletal muscle, its expression level in rhabdomyosarcoma (RMS)-13 cells is threefold to fourfold higher. In basal cell carcinoma (BCC) cells, sonic hedgehog (Shh)-induced cell proliferation is accompanied by induction of D3 and inactivation of D2. Interestingly a fivefold reduction in the growth of BCC in nude mice was observed if D3 expression was knocked down. A decrease in D1 activity has been described in renal clear cell carcinoma, primary liver cancer, lung cancer, and some pituitary tumors, while in breast cancer cells and tissue there is an increase in D1 activity. Furthermore D1 mRNA and activity were found to be decreased in papillary thyroid cancer while D1 and D2 activities were significantly higher in follicular thyroid cancer tissue, in follicular adenoma, and in anaplastic thyroid cancer. It is conceivable that understanding how deiodinase dysregulation in tumor cells affect thyroid hormone signaling and possibly interfere with tumor progression could lead to new antineoplastic approaches.
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Affiliation(s)
- Sabina Casula
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of MedicineMiami, FL, USA
| | - Antonio C. Bianco
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of MedicineMiami, FL, USA
- *Correspondence: Antonio C. Bianco, University of Miami Miller School of Medicine, Batchelor Research Building, 1400 N.W. 10th Avenue, Suite 601, Miami, FL 33136, USA. e-mail:
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19
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Mohácsik P, Zeöld A, Bianco AC, Gereben B. Thyroid hormone and the neuroglia: both source and target. J Thyroid Res 2011; 2011:215718. [PMID: 21876836 PMCID: PMC3163027 DOI: 10.4061/2011/215718] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 05/31/2011] [Accepted: 06/17/2011] [Indexed: 12/15/2022] Open
Abstract
Thyroid hormone plays a crucial role in the development and function of the nervous system. In order to bind to its nuclear receptor and regulate gene transcription thyroxine needs to be activated in the brain. This activation occurs via conversion of thyroxine to T3, which is catalyzed by the type 2 iodothyronine deiodinase (D2) in glial cells, in astrocytes, and tanycytes in the mediobasal hypothalamus. We discuss how thyroid hormone affects glial cell function followed by an overview on the fine-tuned regulation of T3 generation by D2 in different glial subtypes. Recent evidence on the direct paracrine impact of glial D2 on neuronal gene expression underlines the importance of glial-neuronal interaction in thyroid hormone regulation as a major regulatory pathway in the brain in health and disease.
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Affiliation(s)
- Petra Mohácsik
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, H-1083, Hungary
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20
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Chik CL, Price DM, Ho AK. Histone modifications on the adrenergic induction of type II deiodinase in rat pinealocytes. Mol Cell Endocrinol 2011; 343:63-70. [PMID: 21704117 DOI: 10.1016/j.mce.2011.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/02/2011] [Accepted: 06/09/2011] [Indexed: 10/18/2022]
Abstract
Histone modifications have been shown to play an important role in regulating gene expression. In this study, we investigated the impact of histone modifications on the adrenergic-regulated transcription of type 2 deiodinase (Dio2), a CREB-target gene in the rat pinealocyte. Treatment of pinealocytes with inhibitors of aurora C, a histone kinase, resulted in an inhibitory effect on the adrenergic-stimulated histone H3 Ser10 phosphorylation and Dio2 transcription. Given the established link between histone phosphorylation and acetylation, the role of histone acetylation on the adrenergic-induced Dio2 transcription was investigated. Treatment of pinealocytes with histone deacetylase inhibitors inhibited the adrenergic-induced Dio2 transcription. Chromatin immunoprecipitation with antibodies against acetylated Lys14 of H3 showed an increase in DNA recovery of the promoter region of Dio2 following treatment with trichostatin A. Together, our results indicate that, beside activation of CREB, epigenetic factors such as histone modifications also play an important role in regulating Dio2 transcription.
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Affiliation(s)
- Constance L Chik
- Department of Medicine (CLC) and Department of Physiology (DMP, AKH), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
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21
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Liao XH, Di Cosmo C, Dumitrescu AM, Hernandez A, Van Sande J, St Germain DL, Weiss RE, Galton VA, Refetoff S. Distinct roles of deiodinases on the phenotype of Mct8 defect: a comparison of eight different mouse genotypes. Endocrinology 2011; 152:1180-91. [PMID: 21285310 PMCID: PMC3040057 DOI: 10.1210/en.2010-0900] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mice deficient in the thyroid hormone (TH) transporter Mct8 (Mct8KO) have increased 5'-deiodination and impaired TH secretion and excretion. These and other unknown mechanisms result in the low-serum T(4), high T(3), and low rT(3) levels characteristic of Mct8 defects. We investigated to what extent each of the 5'-deiodinases (D1, D2) contributes to the serum TH abnormalities of the Mct8KO by generating mice with all combinations of Mct8 and D1 and/or D2 deficiencies and comparing the resulting eight genotypes. Adding D1 deficiency to that of Mct8 corrected the serum TH abnormalities of Mct8KO mice, normalized brain T(3) content, and reduced the impaired expression of TH-responsive genes. In contrast, Mct8D2KO mice maintained the serum TH abnormalities of Mct8KO mice. However, the serum TSH level increased 27-fold, suggesting a severely impaired hypothalamo-pituitary-thyroid axis. The brain of Mct8D2KO manifested a pattern of more severe impairment of TH action than Mct8KO alone. In triple Mct8D1D2KO mice, the markedly increased serum TH levels produced milder brain defect than that of Mct8D2KO at the expense of more severe liver thyrotoxicosis. Additionally, we observed that mice deficient in D2 had an unexplained marked reduction in the thyroid growth response to TSH. Our studies on these eight genotypes provide a unique insight into the complex interplay of the deiodinases in the Mct8 defect and suggest that D1 contributes to the increased serum T(3) in Mct8 deficiency, whereas D2 mainly functions locally, converting T(4) to T(3) to compensate for distinct cellular TH depletion in Mct8KO mice.
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Affiliation(s)
- Xiao-Hui Liao
- Department of Medicine, The University of Chicago, MC3090, 5841 South Maryland Avenue, Chicago, Illinois 60637, USA
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22
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Araujo RL, Andrade BM, Padrón AS, Gaidhu MP, Perry RLS, Carvalho DP, Ceddia RB. High-fat diet increases thyrotropin and oxygen consumption without altering circulating 3,5,3'-triiodothyronine (T3) and thyroxine in rats: the role of iodothyronine deiodinases, reverse T3 production, and whole-body fat oxidation. Endocrinology 2010; 151:3460-9. [PMID: 20410193 DOI: 10.1210/en.2010-0026] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This study investigated the effects of obesity induced by high-fat (HF) diet on thyroid function and whole-body energy balance. To accomplish that, we assessed the effects of 8 wk of HF diet on several parameters of hypothalamus-pituitary-thyroid axis function. Serum total T(4) and T(3), rT(3), and TSH, the activity of type 1 and type 2 deiodinases in central and peripheral tissues were determined. Also, we measured in vivo energy balance, substrate partitioning, and markers of leptin resistance. Here we provide novel evidence that prolonged positive energy balance acquired by feeding a HF diet induced hyperactivation of the hypothalamus-pituitary-thyroid axis, which was characterized by 2.24-, 1.6-, and 3.7-fold elevations in hypothalamic TRH expression, thyroid iodide uptake, and serum TSH, respectively. Serum T(4) and T(3) were normal together with augmented deiodinase type 1 activity in liver (1.3-fold) and kidney (1.2-fold) and increased (1.5-fold) serum rT3 in HF rats. Despite no increase in circulating levels of T(3) and T(4), whole-body oxygen consumption was increased, and substrate metabolism was shifted toward fat oxidation in HF rats. These in vivo metabolic adjustments were mainly driven by the fat content of the diet. Furthermore, spontaneous dark cycle physical activity was reduced by 30% in rats fed a HF diet, which limited energy expenditure and favored the development of obesity. Our findings provide new insight into the endocrine and physiological mechanisms that underlie the alterations in thyroid hormone availability, energy balance, and metabolic partitioning in HF diet-induced obesity.
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Affiliation(s)
- R L Araujo
- Muscle Health Research Center, School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Ontario, Canada M3J 1P3
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23
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Christoffolete MA, Doleschall M, Egri P, Liposits Z, Zavacki AM, Bianco AC, Gereben B. Regulation of thyroid hormone activation via the liver X-receptor/retinoid X-receptor pathway. J Endocrinol 2010; 205:179-86. [PMID: 20176747 PMCID: PMC3133926 DOI: 10.1677/joe-09-0448] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Thyroid hormone receptor (TR) and liver X-receptor (LXR) are the master regulators of lipid metabolism. Remarkably, a mouse with a targeted deletion of both LXR alpha and LXR beta is resistant to western diet-induced obesity, and exhibits ectopic liver expression of the thyroid hormone activating type 2 deiodinase (D2). We hypothesized that LXR/retinoid X-receptor (RXR) signaling inhibits hepatic D2 expression, and studied this using a luciferase reporter containing the human DIO2 (hDIO2) promoter in HepG2 cells. Given that, in contrast to mammals, the chicken liver normally expresses D2, the chicken DIO2 (cDIO2) promoter was also studied. 22(R)-OH-cholesterol negatively regulated hDIO2 in a dose-dependent manner (100 microM, approximately twofold), while it failed to affect the cDIO2 promoter. Truncations in the hDIO2 promoter identified the region -901 to -584 bp as critical for negative regulation. We also investigated if 9-cis retinoic acid (9-cis RA), the ligand for the heterodimeric partner of TR and LXR, RXR, could regulate the hDIO2 promoter. Notably, 9-cis RA repressed the hDIO2 luciferase reporter (1 microM, approximately fourfold) in a dose-dependent manner, while coexpression of an inactive mutant RXR abolished this effect. However, it is unlikely that RXR homodimers mediate the repression of hDIO2 since mutagenesis of a DR-1 at -506 bp did not interfere with 9-cis RA-mediated repression. Our data indicate that hDIO2 transcription is negatively regulated by both 22(R)-OH-cholesterol and 9-cis RA, which is consistent with LXR/RXR involvement. In vivo, the inhibition of D2-mediated tri-iodothyronine (T(3)) production by cholesterol/9-cis RA could function as a feedback loop, given that T(3) decreases hepatic cholesterol levels.
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24
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Toyoda N, Yasuzawa-Amano S, Nomura E, Yamauchi A, Nishimura K, Ukita C, Morimoto S, Kosaki A, Iwasaka T, Harney JW, Larsen PR, Nishikawa M. Thyroid hormone activation in vascular smooth muscle cells is negatively regulated by glucocorticoid. Thyroid 2009; 19:755-63. [PMID: 19508118 PMCID: PMC2857441 DOI: 10.1089/thy.2009.0044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Type 2 iodothyronine deiodinase (D2) catalyzes the production of triiodothyronine from thyroxine. D2 is present in rat aorta media, and there is a circadian variation in the D2 expression. In rat aorta media, the D2 activity exhibited the maximal value at 1200 hour and low value between 1800 and 2400 hour. To understand the mechanisms that induce the circadian variation in the D2 expression, we examined the effects of glucocorticoid on the D2 activity and mRNA in rat aorta media and cultured vascular smooth muscle cells (VSMCs). METHODS The effects of intrinsic and extrinsic glucocorticoid on the D2 activity and mRNA in rat aorta media were studied using metyrapone, a corticosterone synthesis inhibitor, and dexamethasone (DEX). Further, the effects of DEX on D2 expression were studied using the cultured rat VSMCs. RESULTS The trough values of D2 activity and mRNA at 2100 hour were increased by the treatment with metyrapone. On the other hand, the peak values of D2 activity and mRNA were decreased by the treatment with DEX. D2 activity and mRNA in cultured rat VSMCs were increased by the addition of 10(-3) M dibutyryl cyclic adenosine monophosphate [(Bu)(2)cAMP]. The increments were reduced by coincubation with 10(-6) M DEX. CONCLUSIONS These results suggest that glucocorticoids might directly suppress the D2 expression in rat VSMCs induced by a cAMP-dependent mechanism.
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Affiliation(s)
- Nagaoki Toyoda
- Department of Internal Medicine II, Kansai Medical University, Hirakata-City, Osaka, Japan.
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25
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Gereben B, Zavacki AM, Ribich S, Kim BW, Huang SA, Simonides WS, Zeöld A, Bianco AC. Cellular and molecular basis of deiodinase-regulated thyroid hormone signaling. Endocr Rev 2008; 29:898-938. [PMID: 18815314 PMCID: PMC2647704 DOI: 10.1210/er.2008-0019] [Citation(s) in RCA: 563] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 08/15/2008] [Indexed: 02/06/2023]
Abstract
The iodothyronine deiodinases initiate or terminate thyroid hormone action and therefore are critical for the biological effects mediated by thyroid hormone. Over the years, research has focused on their role in preserving serum levels of the biologically active molecule T(3) during iodine deficiency. More recently, a fascinating new role of these enzymes has been unveiled. The activating deiodinase (D2) and the inactivating deiodinase (D3) can locally increase or decrease thyroid hormone signaling in a tissue- and temporal-specific fashion, independent of changes in thyroid hormone serum concentrations. This mechanism is particularly relevant because deiodinase expression can be modulated by a wide variety of endogenous signaling molecules such as sonic hedgehog, nuclear factor-kappaB, growth factors, bile acids, hypoxia-inducible factor-1alpha, as well as a growing number of xenobiotic substances. In light of these findings, it seems clear that deiodinases play a much broader role than once thought, with great ramifications for the control of thyroid hormone signaling during vertebrate development and metamorphosis, as well as injury response, tissue repair, hypothalamic function, and energy homeostasis in adults.
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Affiliation(s)
- Balázs Gereben
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
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26
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Davies JS, Kotokorpi P, Lindahl U, Oscarsson J, Wells T, Mode A. Effects of the synthetic liver X receptor agonist T0901317 on the growth hormone and thyroid hormone axes in male rats. Endocrine 2008; 33:196-204. [PMID: 18473193 DOI: 10.1007/s12020-008-9067-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 04/25/2008] [Accepted: 04/30/2008] [Indexed: 10/22/2022]
Abstract
Liver X receptors (LXRs), activated by oxysterols, play an important role in the regulation of lipid and glucose metabolism, which is also markedly dependent on thyroid hormone and growth hormone (GH) status. Here, we investigated how a 1-week exposure to the synthetic LXR agonist T0901317 affected GH secretion and thyroid hormone status in male rats. While the pulse frequency of GH secretion was marginally affected there was a highly significant decrease in the triiodo-L-thyronine/thyroxine (T3/T4) ratio in plasma. This effect was associated with decreased expression of deiodinase 1 (DIO1) and 2 (DIO2) mRNA in the liver and thyroid gland, respectively. Expression of sterol regulatory element binding protein-1c (SREBP-1c), the hallmark of stimulated lipogenesis, was markedly increased in both thyroid and pituitary implying that protracted pharmacological LXR activation may promote lipid accumulation in these endocrine tissues. These findings suggest that attention must be given to pituitary hormone dependent axes when developing therapeutic strategies based on agonism of the LXRs, e.g. for treatment of atherosclerosis.
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Affiliation(s)
- Jeffrey S Davies
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3US, UK
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27
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Canettieri G, Franchi A, Guardia MD, Morantte I, Santaguida MG, Harney JW, Larsen PR, Centanni M. Activation of thyroid hormone is transcriptionally regulated by epidermal growth factor in human placenta-derived JEG3 cells. Endocrinology 2008; 149:695-702. [PMID: 17991726 PMCID: PMC2219305 DOI: 10.1210/en.2007-0779] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 10/30/2007] [Indexed: 01/22/2023]
Abstract
Human type II deiodinase is a master regulator of thyroid hormone activation in several tissues. In placenta, type II deiodinase mRNA levels and enzymatic activity are elevated only during the first trimester of pregnancy and then progressively decline. During this early stage, mitogens such as epidermal growth factor (EGF) have been shown to promote the proliferation of the trophoblast by acting through multiple mechanisms. Here we show that EGF modulates transcription of human type II deiodinase gene (Dio2) through distinct signaling pathways, leading to the assembly of a heterogeneous transcription factor complex. Gene expression and deiodination assays have shown that EGF promptly induces a short-lived Dio2 mRNA and enzymatic activity. The induction is mediated by ERK and p38 kinases, as demonstrated by selective inhibition or overexpression of different mitogen-activated kinases. Reporter assays of mutant constructs indicate that EGF-induced transcriptional activity on Dio2 promoter is mediated by the cAMP response element (CRE) and does not involve the activating protein 1 site. With functional and biochemical approaches, we have demonstrated that the EGF stimulation culminates with the assembly and recruitment over the Dio2 CRE of a composite complex, which consists of c-Jun, c-Fos, and CRE-binding protein. These results further support the hypothesis that placental iodothyronine metabolism is critical during early pregnancy.
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Affiliation(s)
- Gianluca Canettieri
- Laboratory of Molecular Oncology, Dipartimento di Medicina Sperimentale, Viale Regina Elena, 324-00161, Rome, Italy.
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28
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Chik CL, Wloka MT, Price DM, Ho AK. The role of repressor proteins in the adrenergic induction of type II iodothyronine deiodinase in rat pinealocytes. Endocrinology 2007; 148:3523-31. [PMID: 17446180 DOI: 10.1210/en.2007-0166] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study, we investigated the transcriptional regulation of the adrenergic induction of type II iodothyronine deiodinase (Dio2) in rat pinealocytes. Treatment of pinealocytes with norepinephrine (NE) caused an increase in the mRNA level of Dio2 that peaked around 2 h and declined over the next 5 h. Both beta- and alpha1-adrenergic receptors contributed to the NE induction of Dio2 expression through a cAMP/protein kinase A mechanism. In pinealocytes that had been stimulated by NE, inhibition of transcription by actinomycin had no discernible effect on Dio2 expression. In contrast, inhibition of protein synthesis by cycloheximide enhanced the NE induction of Dio2 expression, suggesting the involvement of a repressor protein. Transient transfection of pinealocytes with adenovirus expressing small interfering RNA against Fos-related antigen 2 (Fra2) enhanced the NE induction of Dio2 expression, whereas the effect of overexpression of the full-length transcript of Fra2 was inhibitory. Time-course study indicated that preventing the NE induction of Fra2 enhanced the NE induction of Dio2 after 3 h, and the enhancement persisted beyond 6 h after NE stimulation. In comparison, transient transfection of pinealocytes with small interfering RNA against inducible cAMP early repressor (Icer) had no effect on the NE induction of Dio2 expression, whereas overexpression of the full-length transcript of Icer caused a small reduction of the NE-stimulated Dio2 expression. Together, our results support Fra-2 as an important transcriptional repressor that helps shape the time profile of the adrenergic induction of Dio2 expression in the rat pineal gland.
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Affiliation(s)
- C L Chik
- Department of Physiology, Faculty of Medicine and Dentistry, 7-26 Medical Sciences Building, Edmonton, University of Alberta, Canada T6G 2H7
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29
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Zeöld A, Doleschall M, Haffner MC, Capelo LP, Menyhért J, Liposits Z, da Silva WS, Bianco AC, Kacskovics I, Fekete C, Gereben B. Characterization of the nuclear factor-kappa B responsiveness of the human dio2 gene. Endocrinology 2006; 147:4419-29. [PMID: 16728495 DOI: 10.1210/en.2005-1608] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Type 2 iodothyronine deiodinase (D2) activates T4 by deiodination to T3, a process being the source of most T3 present in the brain. In the mediobasal hypothalamus, expression of the dio2 gene is potently activated by administration of bacterial lipopolysaccharide (LPS), which in turn mediates the modifications in thyroid homeostasis typically observed in patients with nonthyroidal illness syndrome. Here we show that LPS-induced D2 expression is also observed in human MSTO-211H cells that endogenously express D2. Exposure to LPS rapidly doubled D2 activity by a mechanism that was partially blocked by the nuclear factor-B (NF-B) inhibitor sulfasalazine. Next, the human dio2 5'-flanking region promoter assay was used in HC11 cells and the p65/NF-kappa B responsiveness mapped to the 3' approximately 600-bp region of hdio2 5'-flanking region, with an approximately 15-fold induction. Semiquantitative EMSA identified the strongest NF-B binding sites at the positions -683 bp (called no. 2) and -198 bp (no. 5) 5' to the transcriptional starting site. Despite the very similar NF-kappa B binding affinity of these two sites, site-directed mutagenesis and promoter assay indicated that only site no. 5 possessed transactivation potency in the presence of the p65 subunit of NF-kappa B. Other cytokine mediators such as signal transducer and activator of transcription-3 (STAT3) or signal transducer and activator of transcription-5 (STAT5) did not induce transcription of the dio2 gene. Our results indicate that inflammatory signals regulate D2 expression predominantly via the NF-kappa B pathway in a direct transcriptional manner and could contribute to the changes in thyroid economy observed in nonthyroidal illness syndrome during infection.
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Affiliation(s)
- Anikó Zeöld
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Faculty of Information Technology, Péter Pázmány Catholic University, Budapest H-1083, Hungary
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30
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Dentice M, Cordeddu V, Rosica A, Ferrara AM, Santarpia L, Salvatore D, Chiovato L, Perri A, Moschini L, Fazzini C, Olivieri A, Costa P, Stoppioni V, Baserga M, De Felice M, Sorcini M, Fenzi G, Di Lauro R, Tartaglia M, Macchia PE. Missense mutation in the transcription factor NKX2-5: a novel molecular event in the pathogenesis of thyroid dysgenesis. J Clin Endocrinol Metab 2006; 91:1428-33. [PMID: 16418214 DOI: 10.1210/jc.2005-1350] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Congenital hypothyroidism (CH) is a common endocrine disorder with an incidence of 1:3000-4000 at birth. In 80-85% of cases, CH is caused by defects in thyroid organogenesis, resulting in absent, ectopically located, and/or severely reduced gland [thyroid dysgenesis (TD)]. Mutations in genes controlling thyroid development have demonstrated that in a few cases, TD is a Mendelian trait. However, accumulating evidence supports the view that the genetics of TD are complex, possibly with a polygenic/multifactorial basis. A higher prevalence of congenital heart disease has been documented in children with CH than in the general population. Such an association suggests a possible pathogenic role of genes involved in both heart and thyroid development. NKX2-5 encodes a homeodomain-containing transcription factor with a major role in heart development, and mutations affecting this gene have been reported in individuals with congenital heart disease. OBJECTIVE In the present work we investigated the possible involvement of NKX2-5 mutations in TD. RESULTS Our results indicate that Nkx2-5(-/-) embryos exhibit thyroid bud hypoplasia, providing evidence that NKX2-5 plays a role in thyroid organogenesis and that NKX2-5 mutations contribute to TD. NKX2-5 mutational screening in 241 patients with TD allowed the identification of three heterozygous missense changes (R25C, A119S, and R161P) in four patients with TD. Functional characterization of the three mutations demonstrated reduced DNA binding and/or transactivation properties, with a dominant-negative effect on wild-type NKX2-5. CONCLUSION Our results suggest a previously unknown role of NKX2-5 in the pathogenesis of TD.
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Affiliation(s)
- Monica Dentice
- Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Università di Napoli Federico II, Via S. Pansin 5, 80131 Naples, Italy
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31
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Dentice M, Luongo C, Elefante A, Ambrosio R, Salzano S, Zannini M, Nitsch R, Di Lauro R, Rossi G, Fenzi G, Salvatore D. Pendrin is a novel in vivo downstream target gene of the TTF-1/Nkx-2.1 homeodomain transcription factor in differentiated thyroid cells. Mol Cell Biol 2005; 25:10171-82. [PMID: 16260629 PMCID: PMC1280265 DOI: 10.1128/mcb.25.22.10171-10182.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thyroid transcription factor gene 1 (TTF-1) is a homeobox-containing gene involved in thyroid organogenesis. During early thyroid development, the homeobox gene Nkx-2.5 is expressed in thyroid precursor cells coincident with the appearance of TTF-1. The aim of this study was to investigate the molecular mechanisms underlying thyroid-specific gene expression. We show that the Nkx-2.5 C terminus interacts with the TTF-1 homeodomain and, moreover, that the expression of a dominant-negative Nkx-2.5 isoform (N188K) in thyroid cells reduces TTF-1-driven transcription by titrating TTF-1 away from its target DNA. This process reduced the expression of several thyroid-specific genes, including pendrin and thyroglobulin. Similarly, down-regulation of TTF-1 by RNA interference reduced the expression of both genes, whose promoters are sensitive to and directly associate with TTF-1 in the chromatin context. In conclusion, we demonstrate that pendrin and thyroglobulin are downstream targets in vivo of TTF-1, whose action is a prime factor in controlling thyroid differentiation in vivo.
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Affiliation(s)
- Monica Dentice
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli Federico II, 80131 Naples, Italy
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Abstract
Recent identification of new selenocysteine-containing proteins has revealed relationships between the two trace elements selenium (Se) and iodine and the hormone network. Several selenoproteins participate in the protection of thyrocytes from damage by H(2)O(2) produced for thyroid hormone biosynthesis. Iodothyronine deiodinases are selenoproteins contributing to systemic or local thyroid hormone homeostasis. The Se content in endocrine tissues (thyroid, adrenals, pituitary, testes, ovary) is higher than in many other organs. Nutritional Se depletion results in retention, whereas Se repletion is followed by a rapid accumulation of Se in endocrine tissues, reproductive organs, and the brain. Selenoproteins such as thioredoxin reductases constitute the link between the Se metabolism and the regulation of transcription by redox sensitive ligand-modulated nuclear hormone receptors. Hormones and growth factors regulate the expression of selenoproteins and, conversely, Se supply modulates hormone actions. Selenoproteins are involved in bone metabolism as well as functions of the endocrine pancreas and adrenal glands. Furthermore, spermatogenesis depends on adequate Se supply, whereas Se excess may impair ovarian function. Comparative analysis of the genomes of several life forms reveals that higher mammals contain a limited number of identical genes encoding newly detected selenocysteine-containing proteins.
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Affiliation(s)
- J Köhrle
- Institut für Experimentelle Endokrinologie, Charité, Humboldt Universität zu Berlin, Schumannstrasse 20/21, D-10098 Berlin, Germany.
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33
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Margaill I, Royer J, Lerouet D, Ramaugé M, Le Goascogne C, Li WW, Plotkine M, Pierre M, Courtin F. Induction of type 2 iodothyronine deiodinase in astrocytes after transient focal cerebral ischemia in the rat. J Cereb Blood Flow Metab 2005; 25:468-76. [PMID: 15674235 DOI: 10.1038/sj.jcbfm.9600041] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study investigated the expression of deiodinases of thyroid hormones in the rat brain after transient occlusion of the middle cerebral artery. The activity of type 2 deiodinase (D2), which catalyzes the deiodination of thyroxine into the more active thyroid hormone 3,5,3'-triiodothyronine, was strongly increased by cerebral ischemia at 6 and 24 hours in the striatum and at 24 hours in the cerebral cortex. The activity of type 3 deiodinase, which catalyzes the inactivation of thyroid hormones, was not affected by ischemia. In situ hybridization showed, as soon as 6 hours, an upregulation of the expression of D2 mRNA in the ipsilateral striatum, which disappeared at 24 hours. In the ipsilateral cortex, the induction of D2 mRNA started at 6 hours, was increased at 24 hours and finally declined at 72 hours. These results were confirmed by reverse transcription-PCR for D2 mRNA in the striatum and cerebral cortex. The upregulation of D2 mRNA after ischemia was mainly localized in astrocytic cell bodies. These results show that D2 is rapidly induced in astrocytes after ischemic stroke. Future work will include the exploration of the role of the upregulation of this enzyme, responsible for local 3,5,3'-triiodothyronine production as a neuroprotective mechanism in the brain.
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Affiliation(s)
- Isabelle Margaill
- Laboratoire de Pharmacologie, Université René Descartes, Paris, France
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34
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Wassen FWJS, Klootwijk W, Kaptein E, Duncker DJ, Visser TJ, Kuiper GGJM. Characteristics and thyroid state-dependent regulation of iodothyronine deiodinases in pigs. Endocrinology 2004; 145:4251-63. [PMID: 15192045 DOI: 10.1210/en.2004-0356] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Three iodothyronine deiodinases (D1, D2, and D3) regulate local and systemic availability of thyroid hormone. D1 and D2 activate the prohormone T4 to the thyromimetic T3, and D3 inactivates T4 and T3 to rT3 and 3,3'-diiodothyronine, respectively. The expression of the three deiodinases is tightly regulated with regard to developmental stage and cell type to provide fine tuning of T3 supply to target cells. Most studies regarding distribution and regulation of deiodinases have been carried out in rodents. However, in different respects, rodents do not seem to be the optimal experimental model for human thyroid hormone physiology. For instance, D2 expression has been observed in human thyroid and skeletal muscle but not in these tissues in rodents. In this study, we have explored the pig as an alternative model. Porcine D1, D2, and D3 were cloned by RT-PCR, and their catalytic properties were shown to be virtually identical to those reported for human and rodent deiodinases. The tissue distribution of deiodinases was studied in normal pigs and in pigs made hypothyroid by methimazole treatment or in pigs made hyperthyroid by T4 treatment. D1 activity in liver and kidney was increased in T4-treated pigs. D2 activities in cerebrum and pituitary were decreased after T4 treatment and strongly increased after methimazole treatment. Remarkably, D2 activity in thyroid and skeletal muscle was induced in hypothyroid pigs. Significant expression of D3 was observed in cerebrum and was positively regulated by thyroid state. In conclusion, the pig appears to be a valuable model for human thyroid hormone physiology. The expression of D2 activity in thyroid and skeletal muscle is of particular interest for studies on the importance of this enzyme in (hypothyroid) humans.
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Affiliation(s)
- Frank W J S Wassen
- Department of Internal Medicine, Room Ee 502, Erasmus Medical Center, Dr Molewaterplein 50, 3015 GE Rotterdam, The Netherlands
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Moeller LC, Kimura S, Kusakabe T, Liao XH, Van Sande J, Refetoff S. Hypothyroidism in thyroid transcription factor 1 haploinsufficiency is caused by reduced expression of the thyroid-stimulating hormone receptor. Mol Endocrinol 2003; 17:2295-302. [PMID: 12907760 DOI: 10.1210/me.2003-0175] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Humans expressing one allele of the thyroid transcription factor 1 (TTF1) gene have neurological symptoms and increased serum TSH with variable degrees of hypothyroidism. Ttf1+/- mice have also poor coordination and increased serum TSH concentration (205 +/- 22 vs. 92 +/- 12 mU/liter; P < 0.001) and slightly lower T4 (46 +/- 3 vs. 63 +/- 6 nmol/liter; P < 0.02) as compared with Ttf1+/+ mice. To determine whether the hypothyroidism is of central or primary origin, we examined the bioactivity of TSH, thyroidal response to exogenous TSH and the expression of genes regulated by TTF1. TSH bioactivity was normal, but T4 response to a low but not high dose of TSH was significantly reduced in the Ttf1+/- mice (5.5 +/- 2.2 vs. 15.3 +/- 4.1 nmol/liter; P < 0.03), indicating a reduced thyroidal response. Thyroid mRNAs were measured by real-time PCR (Ttf1+/+ littermates = 100%). Ttf1+/- mice had half the levels of TTF1 mRNA (54 +/- 9; P < 0.01) and protein, confirming their haploinsufficiency. Significantly lower levels of mRNAs were observed for two of the three genes with TTF1 cis elements: TSH receptor (TSHr, 57 +/- 4%; P < 0.002), thyroglobulin (63 +/- 7%; P < 0.005), but not thyroid peroxidase (81 +/- 12%; P > 0.05). No significant difference between the two genotypes was found for Pax8, sodium iodide symporter, and iodothyronine deiodinase 1. These results show that Ttf1 haploinsufficiency causes a reduction in the expression of TSHr and thyroglobulin, genes with TTF1 binding sites in their promoter regions. The low TSHr is only partially compensated by an increase in TSH secretion because T4 remains mildly reduced. However, administration of a larger amount of TSH obliterates the response differences by saturating a reduced amount of receptor.
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Affiliation(s)
- Lars C Moeller
- Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA
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Dentice M, Morisco C, Vitale M, Rossi G, Fenzi G, Salvatore D. The different cardiac expression of the type 2 iodothyronine deiodinase gene between human and rat is related to the differential response of the Dio2 genes to Nkx-2.5 and GATA-4 transcription factors. Mol Endocrinol 2003; 17:1508-21. [PMID: 12775767 DOI: 10.1210/me.2002-0348] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
By producing T3 from T4, type 2 iodothyronine deiodinase (D2) catalyzes the first step in the cascade underlying the effect exerted by thyroid hormone. Type 2 iodothyronine deiodinase mRNA is expressed at high levels in human heart but is barely detectable in the corresponding rodent tissue. Although the heart is a major target of thyroid hormone, the role of cardiac D2 and the factors that regulate its expression are unknown. Here we report that the human Dio2 promoter is very sensitive to the cardiac transcription factors Nkx-2.5 and GATA-4. Nkx-2.5 transactivates a 6.5-kb human (h)Dio2-chloramphenicol acetyltransferase construct, with maximal induction reached with a 633-bp proximal promoter region. Interestingly, despite 73% identity with the corresponding human region, the rat Dio2 promoter is much less responsive to Nkx-2.5 induction. Using EMSA, we found that two sites in the human promoter (C and D) specifically bind Nkx-2.5. In coexpression studies, GATA-4 alone was a poor inducer of the hDio2 promoter; however in synergy with Nkx-2.5, it activated D2 reporter gene expression in the human, but not the rat promoter. Functional analysis showed that both C and D sites are required for the complete Nkx-2.5 response and for the Nkx-2.5/GATA-4 synergistic effect. In neonatal rat primary myocardiocytes, most of the hDio2-chloramphenicol acetyltransferase activity was suppressed by mutation of the Nkx-2.5 binding sites. Finally, a mutant Nkx-2.5 protein (N188K), which causes, in heterozygosity, congenital heart diseases, did not transactivate the Dio2 promoter and interfered with its activity in cardiomyocytes, possibly by titrating endogenous Nkx-2.5 protein away from the promoter. In conclusion, this study shows that Nkx-2.5 and GATA-4 play prime roles in Dio2 gene regulation in the human heart and suggests that it is their synergistic action in humans that causes the differential expression of the cardiac Dio2 gene between humans and rats.
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Affiliation(s)
- Monica Dentice
- Dipartimento di Biologia e Pathologia Cellulare e Molecolare, Facolta di Medicina e Chirurgia, Universita degli Studi di Napoli "Federico II," 80131 Naples, Italy
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Wang LH, Chmelik R, Nirenberg M. Sequence-specific DNA binding by the vnd/NK-2 homeodomain of Drosophila. Proc Natl Acad Sci U S A 2002; 99:12721-6. [PMID: 12232052 PMCID: PMC130527 DOI: 10.1073/pnas.202461199] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2002] [Indexed: 01/05/2023] Open
Abstract
The ventral nervous system defective (vnd)/NK-2 homeodomain and some flanking amino acid residues were expressed in Escherichia coli, purified to homogeneity, and the protein was covalently coupled to Sepharose. Oligodeoxynucleotides that contained 16-bp random sequences were purified by vnd/NK-2 affinity column chromatography, cloned, and sequenced. The consensus nucleotide sequence of the vnd/NK-2 homeodomain binding site was shown to be T(T/C)AAGTG(G/C). The apparent equilibrium dissociation constant (K(D)) of the vnd/NK-2 homeodomain for the consensus sequence is 1.9 x 10(-10) M. In addition, results of competition between oligodeoxynucleotides for binding to the vnd/NK-2 homeodomain and determination of the apparent K(D) values of oligodeoxynucleotides that differ from the consensus sequence by only a single base pair demonstrate that the four central nucleotides, AAGT, in this sequence play a major role in determining the affinity of binding.
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Affiliation(s)
- Lan-Hsiang Wang
- Laboratory of Biochemical Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1654, USA
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Gereben B, Kollár A, Harney JW, Larsen PR. The mRNA structure has potent regulatory effects on type 2 iodothyronine deiodinase expression. Mol Endocrinol 2002; 16:1667-79. [PMID: 12089359 DOI: 10.1210/mend.16.7.0879] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Type 2 deiodinase (D2) is a selenoenzyme catalyzing the activation of T(4) to T(3). D2 activity/mRNA ratios are often low, suggesting that there is significant posttranscriptional regulation. The D2 mRNA in higher vertebrates is more than 6 kb, containing long 5' and 3' untranslated regions (UTRs). The D2 5'UTRs are greater than 600 nucleotides and contain 3-5 short open reading frames. These full-length 5'UTRs reduce the D2 translation efficiency approximately 5-fold. The inhibition by human D2 5'UTR is localized to a region containing the first short open reading frame encoding a tripeptide-MKG. This inhibition was abolished by mutating the AUG start codon and weakened by modification of the essential purine of the Kozak consensus. Deletion of the 3.7-kb 3'UTR of the chicken D2 mRNA increased D2 activity approximately 3.8-fold due to an increase in D2 mRNA half-life. In addition, alternatively spliced D2 mRNA transcripts similar in size to the major 6- to 7-kb D2 mRNAs but not encoding an active enzyme are present in both human and chicken tissues. Our results indicate that a number of factors reduce the D2 protein levels. These mechanisms, together with the short half-life of the protein, ensure limited expression of this key regulator of T(4) activation.
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Affiliation(s)
- Balázs Gereben
- Institute of Experimental Medicine, Department of Neurobiology, Budapest H-1083, Hungary
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Bianco AC, Salvatore D, Gereben B, Berry MJ, Larsen PR. Biochemistry, cellular and molecular biology, and physiological roles of the iodothyronine selenodeiodinases. Endocr Rev 2002; 23:38-89. [PMID: 11844744 DOI: 10.1210/edrv.23.1.0455] [Citation(s) in RCA: 1005] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The goal of this review is to place the exciting advances that have occurred in our understanding of the molecular biology of the types 1, 2, and 3 (D1, D2, and D3, respectively) iodothyronine deiodinases into a biochemical and physiological context. We review new data regarding the mechanism of selenoprotein synthesis, the molecular and cellular biological properties of the individual deiodinases, including gene structure, mRNA and protein characteristics, tissue distribution, subcellular localization and topology, enzymatic properties, structure-activity relationships, and regulation of synthesis, inactivation, and degradation. These provide the background for a discussion of their role in thyroid physiology in humans and other vertebrates, including evidence that D2 plays a significant role in human plasma T(3) production. We discuss the pathological role of D3 overexpression causing "consumptive hypothyroidism" as well as our current understanding of the pathophysiology of iodothyronine deiodination during illness and amiodarone therapy. Finally, we review the new insights from analysis of mice with targeted disruption of the Dio2 gene and overexpression of D2 in the myocardium.
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Affiliation(s)
- Antonio C Bianco
- Thyroid Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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Affiliation(s)
- Josef Köhrle
- Division of Molecular Internal Medicine, Medizinische Poliklinik, University of Wuerzburg, D-97070 Wuerzburg, Germany
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