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Li L, Song Y, Shi Y, Sun L. Thyroid Hormone Receptor-β Agonists in NAFLD Therapy: Possibilities and Challenges. J Clin Endocrinol Metab 2023; 108:1602-1613. [PMID: 36746649 DOI: 10.1210/clinem/dgad072] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a progressive metabolic liver disease with an unknown pathogenesis and no FDA-approved drug treatment to date. Hypothyroidism has been identified as a risk factor for NAFLD as thyroxine is required for regulating metabolism in adults. Thyroxine has been shown to reduce fat in the livers of murine models with experimentally induced NAFLD. The use of synthetic thyroxine has been shown to increase lipid metabolism leading to weight loss; however, thyroxine has also been shown to cause many side effects, especially in the heart. Overcoming these cardiac side effects involves designing agonists specific to one of the 2 gene subtypes for the thyroid hormone (TH) receptor (TR), TRβ. While the other TH receptor subtype, TRα, is mainly expressed in the heart and is responsible for thyroxine's cardiac function, TRβ is mainly expressed in the liver and is involved in liver function. Using TRβ-specific agonists to treat NAFLD can prevent cardiac and other adverse side effects. Several TRβ-specific agonists have shown positive therapeutic effects in NAFLD animal models and have entered clinical trials. We seek to provide a comprehensive updated reference of TRβ-specific agonists in this review and explore the future therapeutic potential of TRβ-specific activation in the treatment of NAFLD.
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Affiliation(s)
- Limei Li
- Research Center for Translational Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
| | - Yan Song
- Department of Endocrinology and Metabolism, Changzheng Hospital, Naval Medical University, Shanghai 200003, China
| | - Yongquan Shi
- Department of Endocrinology and Metabolism, Changzheng Hospital, Naval Medical University, Shanghai 200003, China
| | - Liangliang Sun
- Department of Endocrinology and Metabolism, Changzheng Hospital, Naval Medical University, Shanghai 200003, China
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2
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Yao B, Yang C, Pan C, Li Y. Thyroid hormone resistance: Mechanisms and therapeutic development. Mol Cell Endocrinol 2022; 553:111679. [PMID: 35738449 DOI: 10.1016/j.mce.2022.111679] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 05/03/2021] [Accepted: 05/09/2022] [Indexed: 10/18/2022]
Abstract
As an essential primary hormone, thyroid hormone (TH) is indispensable for human growth, development and metabolism. Impairment of TH function in several aspects, including TH synthesis, activation, transportation and receptor-dependent transactivation, can eventually lead to thyroid hormone resistance syndrome (RTH). RTH is a rare syndrome that manifests as a reduced target cell response to TH signaling. The majority of RTH cases are related to thyroid hormone receptor β (TRβ) mutations, and only a few RTH cases are associated with thyroid hormone receptor α (TRα) mutations or other causes. Patients with RTH suffer from goiter, mental retardation, short stature and bradycardia or tachycardia. To date, approximately 170 mutated TRβ variants and more than 20 mutated TRα variants at the amino acid level have been reported in RTH patients. In addition to these mutated proteins, some TR isoforms can also reduce TH function by competing with primary TRs for TRE and RXR binding. Fortunately, different treatments for RTH have been explored with structure-activity relationship (SAR) studies and drug design, and among these treatments. With thyromimetic potency but biochemical properties that differ from those of primary TH (T3 and T4), these TH analogs can bypass specific defective transporters or reactive mutant TRs. However, these compounds must be carefully applied to avoid over activating TRα, which is associated with more severe heart impairment. The structural mechanisms of mutation-induced RTH in the TR ligand-binding domain are summarized in this review. Furthermore, strategies to overcome this resistance for therapeutic development are also discussed.
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Affiliation(s)
- Benqiang Yao
- The State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361005, China
| | - Chunyan Yang
- The State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361005, China.
| | - Chengxi Pan
- The State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361005, China
| | - Yong Li
- The State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361005, China.
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Liao CJ, Huang PS, Chien HT, Lin TK, Yeh CT, Lin KH. Effects of Thyroid Hormones on Lipid Metabolism Pathologies in Non-Alcoholic Fatty Liver Disease. Biomedicines 2022; 10:biomedicines10061232. [PMID: 35740254 PMCID: PMC9219876 DOI: 10.3390/biomedicines10061232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 02/01/2023] Open
Abstract
The typical modern lifestyle contributes to the development of many metabolic-related disorders, as exemplified by metabolic syndrome. How to prevent, resolve, or avoid subsequent deterioration of metabolic disturbances and the development of more serious diseases has become an important and much-discussed health issue. Thus, the question of the physiological and pathological roles of thyroid hormones (THs) in metabolism has never gone out of fashion. Although THs influence almost all organs, the liver is one of the most important targets as well as the hub of metabolic homeostasis. When this homeostasis is out of balance, diseases may result. In the current review, we summarize the common features and actions of THs, first focusing on their effects on lipid metabolism in the liver. In the second half of the review, we turn to a consideration of non-alcoholic fatty liver disease (NAFLD), a disease characterized by excessive accumulation of fat in the liver that is independent of heavy alcohol consumption. NAFLD is a growing health problem that currently affects ~25% of the world’s population. Unfortunately, there are currently no approved therapies specific for NAFLD, which, if left uncontrolled, may progress to more serious diseases, such as cirrhosis or liver cancer. This absence of effective treatment can also result in the development of non-alcoholic steatohepatitis (NASH), an aggressive form of NAFLD that is the leading cause of liver transplantation in the United States. Because THs play a clear role in hepatic fat metabolism, their potential application in the prevention and treatment of NAFLD has attracted considerable research attention. Studies that have investigated the use of TH-related compounds in the management of NAFLD are also summarized in the latter part of this review. An important take-home point of this review is that a comprehensive understanding of the physiological and pathological roles of THs in liver fat metabolism is possible, despite the complexities of this regulatory axis—an understanding that has clinical value for the specific management of NAFLD.
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Affiliation(s)
- Chia-Jung Liao
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (C.-J.L.); (P.-S.H.)
| | - Po-Shuan Huang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (C.-J.L.); (P.-S.H.)
| | - Hui-Tzu Chien
- Department of Nutrition and Health Sciences, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan;
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan
| | - Tzu-Kang Lin
- Neurosurgery, Fu Jen Catholic University Hospital School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan;
| | - Chau-Ting Yeh
- Liver Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan 333, Taiwan;
| | - Kwang-Huei Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (C.-J.L.); (P.-S.H.)
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan
- Liver Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan 333, Taiwan;
- Department of Biochemistry, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan 333, Taiwan
- Correspondence: ; Tel./Fax: +886-3-2118263
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4
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Zhao M, Xie H, Shan H, Zheng Z, Li G, Li M, Hong L. Development of Thyroid Hormones and Synthetic Thyromimetics in Non-Alcoholic Fatty Liver Disease. Int J Mol Sci 2022; 23:1102. [PMID: 35163026 PMCID: PMC8835192 DOI: 10.3390/ijms23031102] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/12/2022] [Accepted: 01/18/2022] [Indexed: 02/05/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the fastest-growing liver disease in the world. Despite targeted agents which are needed to provide permanent benefits for patients with NAFLD, no drugs have been approved to treat NASH. Thyroid hormone is an important signaling molecule to maintain normal metabolism, and in vivo and vitro studies have shown that regulation of the 3,5,3'-triiodothyronine (T3)/ thyroid hormone receptor (TR) axis is beneficial not only for metabolic symptoms but also for the improvement of NAFLD and even for the repair of liver injury. However, the non-selective regulation of T3 to TR subtypes (TRα/TRβ) could cause unacceptable side effects represented by cardiotoxicity. To avoid deleterious effects, TRβ-selective thyromimetics were developed for NASH studies in recent decades. Herein, we will review the development of thyroid hormones and synthetic thyromimetics based on TR selectivity for NAFLD, and analyze the role of TR-targeted drugs for the treatment of NAFLD in the future.
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Affiliation(s)
- Man Zhao
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (H.X.); (H.S.); (Z.Z.)
| | - Huazhong Xie
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (H.X.); (H.S.); (Z.Z.)
| | - Hao Shan
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (H.X.); (H.S.); (Z.Z.)
| | - Zhihua Zheng
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (H.X.); (H.S.); (Z.Z.)
| | - Guofeng Li
- Health Science Centre, School of Pharmaceutical Sciences, Shenzhen University, Shenzhen 518060, China;
| | - Min Li
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (H.X.); (H.S.); (Z.Z.)
| | - Liang Hong
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (H.X.); (H.S.); (Z.Z.)
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5
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Hypothyroidism-Associated Dyslipidemia: Potential Molecular Mechanisms Leading to NAFLD. Int J Mol Sci 2021; 22:ijms222312797. [PMID: 34884625 PMCID: PMC8657790 DOI: 10.3390/ijms222312797] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 12/31/2022] Open
Abstract
Thyroid hormones control lipid metabolism by exhibiting specific effects on the liver and adipose tissue in a coordinated manner. Different diseases of the thyroid gland can result in hypothyroidism. Hypothyroidism is frequently associated with dyslipidemia. Hypothyroidism-associated dyslipidemia subsequently results in intrahepatic accumulation of fat, leading to nonalcoholic fatty liver disease (NAFLD), which leads to the development of hepatic insulin resistance. The prevalence of NAFLD in the western world is increasing, and evidence of its association with hypothyroidism is accumulating. Since hypothyroidism has been identified as a modifiable risk factor of NAFLD and recent data provides evidence that selective thyroid hormone receptor β (THR-β) agonists are effective in the treatment of dyslipidemia and NAFLD, interest in potential therapeutic options for NAFLD targeting these receptors is growing. In this review, we summarize current knowledge regarding clinical and molecular data exploring the association of hypothyroidism, dyslipidemia and NAFLD.
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6
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Paul-Friedman K, Martin M, Crofton KM, Hsu CW, Sakamuru S, Zhao J, Xia M, Huang R, Stavreva DA, Soni V, Varticovski L, Raziuddin R, Hager GL, Houck KA. Limited Chemical Structural Diversity Found to Modulate Thyroid Hormone Receptor in the Tox21 Chemical Library. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:97009. [PMID: 31566444 PMCID: PMC6792352 DOI: 10.1289/ehp5314] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Thyroid hormone receptors (TRs) are critical endocrine receptors that regulate a multitude of processes in adult and developing organisms, and thyroid hormone disruption is of high concern for neurodevelopmental and reproductive toxicities in particular. To date, only a small number of chemical classes have been identified as possible TR modulators, and the receptors appear highly selective with respect to the ligand structural diversity. Thus, the question of whether TRs are an important screening target for protection of human and wildlife health remains. OBJECTIVE Our goal was to evaluate the hypothesis that there is limited structural diversity among environmentally relevant chemicals capable of modulating TR activity via the collaborative interagency Tox21 project. METHODS We screened the Tox21 chemical library (8,305 unique structures) in a quantitative high-throughput, cell-based reporter gene assay for TR agonist or antagonist activity. Active compounds were further characterized using additional orthogonal assays, including mammalian one-hybrid assays, coactivator recruitment assays, and a high-throughput, fluorescent imaging, nuclear receptor translocation assay. RESULTS Known agonist reference chemicals were readily identified in the TR transactivation assay, but only a single novel, direct agonist was found, the pharmaceutical betamipron. Indirect activation of TR through activation of its heterodimer partner, the retinoid-X-receptor (RXR), was also readily detected by confirmation in an RXR agonist assay. Identifying antagonists with high confidence was a challenge with the presence of significant confounding cytotoxicity and other, non-TR-specific mechanisms common to the transactivation assays. Only three pharmaceuticals-mefenamic acid, diclazuril, and risarestat-were confirmed as antagonists. DISCUSSION The results support limited structural diversity for direct ligand effects on TR and imply that other potential target sites in the thyroid hormone axis should be a greater priority for bioactivity screening for thyroid axis disruptors. https://doi.org/10.1289/EHP5314.
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Affiliation(s)
- Katie Paul-Friedman
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Matt Martin
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Kevin M Crofton
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Chia-Wen Hsu
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Washington, DC, USA
| | - Srilatha Sakamuru
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Jinghua Zhao
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Menghang Xia
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ruili Huang
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Diana A Stavreva
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Vikas Soni
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Lyuba Varticovski
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Razi Raziuddin
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Gordon L Hager
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Keith A Houck
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
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7
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Bianco AC, Dumitrescu A, Gereben B, Ribeiro MO, Fonseca TL, Fernandes GW, Bocco BMLC. Paradigms of Dynamic Control of Thyroid Hormone Signaling. Endocr Rev 2019; 40:1000-1047. [PMID: 31033998 PMCID: PMC6596318 DOI: 10.1210/er.2018-00275] [Citation(s) in RCA: 140] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/15/2019] [Indexed: 12/17/2022]
Abstract
Thyroid hormone (TH) molecules enter cells via membrane transporters and, depending on the cell type, can be activated (i.e., T4 to T3 conversion) or inactivated (i.e., T3 to 3,3'-diiodo-l-thyronine or T4 to reverse T3 conversion). These reactions are catalyzed by the deiodinases. The biologically active hormone, T3, eventually binds to intracellular TH receptors (TRs), TRα and TRβ, and initiate TH signaling, that is, regulation of target genes and other metabolic pathways. At least three families of transmembrane transporters, MCT, OATP, and LAT, facilitate the entry of TH into cells, which follow the gradient of free hormone between the extracellular fluid and the cytoplasm. Inactivation or marked downregulation of TH transporters can dampen TH signaling. At the same time, dynamic modifications in the expression or activity of TRs and transcriptional coregulators can affect positively or negatively the intensity of TH signaling. However, the deiodinases are the element that provides greatest amplitude in dynamic control of TH signaling. Cells that express the activating deiodinase DIO2 can rapidly enhance TH signaling due to intracellular buildup of T3. In contrast, TH signaling is dampened in cells that express the inactivating deiodinase DIO3. This explains how THs can regulate pathways in development, metabolism, and growth, despite rather stable levels in the circulation. As a consequence, TH signaling is unique for each cell (tissue or organ), depending on circulating TH levels and on the exclusive blend of transporters, deiodinases, and TRs present in each cell. In this review we explore the key mechanisms underlying customization of TH signaling during development, in health and in disease states.
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Affiliation(s)
- Antonio C Bianco
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Alexandra Dumitrescu
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Balázs Gereben
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Miriam O Ribeiro
- Developmental Disorders Program, Center of Biologic Sciences and Health, Mackenzie Presbyterian University, São Paulo, São Paulo, Brazil
| | - Tatiana L Fonseca
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Gustavo W Fernandes
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Barbara M L C Bocco
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
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8
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de Souza JS, Ferreira DR, Herai R, Carromeu C, Torres LB, Araujo BHS, Cugola F, Maciel RMB, Muotri AR, Giannocco G. Altered Gene Expression of Thyroid Hormone Transporters and Deiodinases in iPS MeCP2-Knockout Cells-Derived Neurons. Mol Neurobiol 2019; 56:8277-8295. [DOI: 10.1007/s12035-019-01645-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/10/2019] [Indexed: 12/12/2022]
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von Hafe M, Neves JS, Vale C, Borges-Canha M, Leite-Moreira A. The impact of thyroid hormone dysfunction on ischemic heart disease. Endocr Connect 2019; 8:R76-R90. [PMID: 30959486 PMCID: PMC6499922 DOI: 10.1530/ec-19-0096] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 04/02/2019] [Indexed: 12/16/2022]
Abstract
Thyroid hormones have a central role in cardiovascular homeostasis. In myocardium, these hormones stimulate both diastolic myocardial relaxation and systolic myocardial contraction, have a pro-angiogenic effect and an important role in extracellular matrix maintenance. Thyroid hormones modulate cardiac mitochondrial function. Dysfunction of thyroid axis impairs myocardial bioenergetic status. Both overt and subclinical hypothyroidism are associated with a higher incidence of coronary events and an increased risk of heart failure progression. Endothelial function is also impaired in hypothyroid state, with decreased nitric oxide-mediated vascular relaxation. In heart disease, particularly in ischemic heart disease, abnormalities in thyroid hormone levels are common and are an important factor to be considered. In fact, low thyroid hormone levels should be interpreted as a cardiovascular risk factor. Regarding ischemic heart disease, during the late post-myocardial infarction period, thyroid hormones modulate left ventricular structure, function and geometry. Dysfunction of thyroid axis might even be more prevalent in the referred condition since there is an upregulation of type 3 deiodinase in myocardium, producing a state of local cardiac hypothyroidism. In this focused review, we summarize the central pathophysiological and clinical links between altered thyroid function and ischemic heart disease. Finally, we highlight the potential benefits of thyroid hormone supplementation as a therapeutic target in ischemic heart disease.
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Affiliation(s)
- Madalena von Hafe
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - João Sergio Neves
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
- Department of Endocrinology, Diabetes and Metabolism, Centro Hospitalar São João, Porto, Portugal
- Correspondence should be addressed to J S Neves:
| | - Catarina Vale
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Marta Borges-Canha
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
- Department of Endocrinology, Diabetes and Metabolism, Centro Hospitalar São João, Porto, Portugal
| | - Adelino Leite-Moreira
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
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10
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Liu YY, Brent GA. Thyroid hormone and the brain: Mechanisms of action in development and role in protection and promotion of recovery after brain injury. Pharmacol Ther 2018; 186:176-185. [PMID: 29378220 DOI: 10.1016/j.pharmthera.2018.01.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Thyroid hormone (TH) is essential for normal brain development and may also promote recovery and neuronal regeneration after brain injury. TH acts predominantly through the nuclear receptors, TH receptor alpha (THRA) and beta (THRB). Additional factors that impact TH action in the brain include metabolism, activation of thyroxine (T4) to triiodothyronine (T3) by the enzyme 5'-deiodinase Type 2 (Dio2), inactivation by the enzyme 5-deiodinase Type 3 (Dio3) to reverse T3 (rT3), which occurs in glial cells, and uptake by the Mct8 transporter in neurons. Traumatic brain injury (TBI) is associated with inflammation, metabolic alterations and neural death. In clinical studies, central hypothyroidism, due to hypothalamic and pituitary dysfunction, has been found in some individuals after brain injury. TH has been shown, in animal models, to be protective for the damage incurred from brain injury and may have a role to limit injury and promote recovery. Although clinical trials have not yet been reported, findings from in vitro and in vivo models inform potential treatment strategies utilizing TH for protection and promotion of recovery after brain injury.
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Affiliation(s)
- Yan-Yun Liu
- Departments of Medicine and Physiology, David Geffen School of Medicine at UCLA, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, United States
| | - Gregory A Brent
- Departments of Medicine and Physiology, David Geffen School of Medicine at UCLA, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, United States.
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11
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Richard S, Flamant F. Regulation of T3 Availability in the Developing Brain: The Mouse Genetics Contribution. Front Endocrinol (Lausanne) 2018; 9:265. [PMID: 29892264 PMCID: PMC5985302 DOI: 10.3389/fendo.2018.00265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/07/2018] [Indexed: 12/11/2022] Open
Abstract
Alterations in maternal thyroid physiology may have deleterious consequences on the development of the fetal brain, but the underlying mechanisms remain elusive, hampering the development of appropriate therapeutic strategies. The present review sums up the contribution of genetically modified mouse models to this field. In particular, knocking out genes involved in thyroid hormone (TH) deiodination, transport, and storage has significantly improved the picture that we have of the economy of TH in the fetal brain and the underlying genetic program. These data pave the way for future studies to bridge the gap in knowledge between thyroid physiology and brain development.
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12
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Vancamp P, Darras VM. Dissecting the role of regulators of thyroid hormone availability in early brain development: Merits and potential of the chicken embryo model. Mol Cell Endocrinol 2017; 459:71-78. [PMID: 28153797 DOI: 10.1016/j.mce.2017.01.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/24/2017] [Accepted: 01/26/2017] [Indexed: 10/20/2022]
Abstract
Thyroid hormones (THs) are important mediators of vertebrate central nervous system (CNS) development, thereby regulating the expression of a wide variety of genes by binding to nuclear TH receptors. TH transporters and deiodinases are both needed to ensure appropriate intracellular TH availability, but the precise function of each of these regulators and their coaction during brain development is only partially understood. Rodent knockout models already provided some crucial insights, but their in utero development severely hampers research regarding the role of TH regulators during early embryonic stages. The establishment of novel gain- and loss-of-function techniques has boosted the position of externally developing non-mammalian vertebrates as research models in developmental endocrinology. Here, we elaborate on the chicken as a model organism to elucidate the function of TH regulators during embryonic CNS development. The fast-developing, relatively big and accessible embryo allows easy experimental manipulation, especially at early stages of brain development. Recent data on the characterisation and spatiotemporal expression pattern of different TH regulators in embryonic chicken CNS have provided the necessary background to dissect the function of each of them in more detail. We highlight some recent advances and important strategies to investigate the role of TH transporters and deiodinases in various CNS structures like the brain barriers, the cerebellum, the retina and the hypothalamus. Exploiting the advantages of this non-classical model can greatly contribute to complete our understanding of the regulation of TH bioavailability throughout embryonic CNS development.
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Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium.
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13
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Delitala AP, Delitala G, Sioni P, Fanciulli G. Thyroid hormone analogs for the treatment of dyslipidemia: past, present, and future. Curr Med Res Opin 2017; 33:1985-1993. [PMID: 28498022 DOI: 10.1080/03007995.2017.1330259] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Treatment of dyslipidemia is a major burden for public health. Thyroid hormone regulates lipid metabolism by binding the thyroid hormone receptor (TR), but the use of thyroid hormone to treat dyslipidemia is not indicated due to its deleterious effects on heart, bone, and muscle. Thyroid hormone analogs have been conceived to selectively activate TR in the liver, thus reducing potential side-effects. METHODS The authors searched the PubMed database to review TR and the action of thyromimetics in vitro and in animal models. Then, all double-blind, placebo controlled trials that analyzed the use of thyroid hormone analog for the treatment of dyslipidemia in humans were included. Finally, the ongoing research on the use of TR agonists was searched, searching the US National Institutes of Health Registry and the WHO International Clinical Trial Registry Platform (ICTRP). RESULTS Thyromimetics were tested in humans for the treatment of dyslipidemia, as a single therapeutic agent or as an add-on therapy to the traditional lipid-lowering drugs. In most trials, thyromimetics lowered total cholesterol, low-density lipoprotein cholesterol, and triglycerides, but their use has been associated with adverse side-effects, both in pre-clinical studies and in humans. CONCLUSIONS The use of thyromimetics for the treatment of dyslipidemia is not presently recommended. Future possible clinical applications might include their use to promote weight reduction. Thyromimetics might also represent an interesting alternative, both for the treatment of non-alcoholic steatohepatitis, and type 2 diabetes due to their positive effects on insulin sensitivity. Finally, additional experimental and clinical studies are needed for a better comprehension of the effect(s) of a long-term therapy.
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Affiliation(s)
| | - Giuseppe Delitala
- b Department of Clinical and Experimental Medicine , University of Sassari , Sassari , Italy
| | - Paolo Sioni
- a Azienda Ospedaliero-Universitaria di Sassari , Sassari , Italy
| | - Giuseppe Fanciulli
- a Azienda Ospedaliero-Universitaria di Sassari , Sassari , Italy
- b Department of Clinical and Experimental Medicine , University of Sassari , Sassari , Italy
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14
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Flamant F, Gauthier K, Richard S. Genetic Investigation of Thyroid Hormone Receptor Function in the Developing and Adult Brain. Curr Top Dev Biol 2017; 125:303-335. [PMID: 28527576 DOI: 10.1016/bs.ctdb.2017.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Thyroid hormones exert a broad influence on brain development and function, which has been extensively studied over the years. Mouse genetics has brought an important contribution, allowing precise analysis of the interplay between TRα1 and TRβ1 nuclear receptors in neural cells. However, the exact contribution of each receptor, the possible intervention of nongenomic signaling, and the nature of the genetic program that is controlled by the receptors remain poorly understood.
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Affiliation(s)
- Frédéric Flamant
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon cedex, France.
| | - Karine Gauthier
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon cedex, France
| | - Sabine Richard
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon cedex, France
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15
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Elbers LPB, Kastelein JJP, Sjouke B. Thyroid Hormone Mimetics: the Past, Current Status and Future Challenges. Curr Atheroscler Rep 2016; 18:14. [PMID: 26886134 PMCID: PMC4757599 DOI: 10.1007/s11883-016-0564-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The association between thyroid hormone status and plasma levels of low-density lipoprotein cholesterol has raised the awareness for the development of thyroid hormone mimetics as lipid-lowering agents. The discovery of the two main types of thyroid hormone receptors (α and β) as well as the development of novel combinatorial chemistry providing organ specificity has drastically improved the selectivity of these compounds. In the past decades, several thyroid hormone mimetics have been investigated with the purpose of lowering low-density lipoprotein cholesterol levels. However, until now, none of the thyromimetics reached the stage of completing a phase III clinical trial without deleterious side effects. Here, we review the currently available literature on thyromimetics investigated for the treatment of dyslipidemia, their rise, their downfall and the challenges for the development of novel agents.
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Affiliation(s)
- L P B Elbers
- Department of Vascular Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.,Department of Internal Medicine, Medical Center Slotervaart, Amsterdam, The Netherlands
| | - J J P Kastelein
- Department of Vascular Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - B Sjouke
- Department of Vascular Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
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16
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Abstract
Thyroid hormone (TH) is required for normal development as well as regulating metabolism in the adult. The thyroid hormone receptor (TR) isoforms, α and β, are differentially expressed in tissues and have distinct roles in TH signaling. Local activation of thyroxine (T4), to the active form, triiodothyronine (T3), by 5'-deiodinase type 2 (D2) is a key mechanism of TH regulation of metabolism. D2 is expressed in the hypothalamus, white fat, brown adipose tissue (BAT), and skeletal muscle and is required for adaptive thermogenesis. The thyroid gland is regulated by thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH). In addition to TRH/TSH regulation by TH feedback, there is central modulation by nutritional signals, such as leptin, as well as peptides regulating appetite. The nutrient status of the cell provides feedback on TH signaling pathways through epigentic modification of histones. Integration of TH signaling with the adrenergic nervous system occurs peripherally, in liver, white fat, and BAT, but also centrally, in the hypothalamus. TR regulates cholesterol and carbohydrate metabolism through direct actions on gene expression as well as cross-talk with other nuclear receptors, including peroxisome proliferator-activated receptor (PPAR), liver X receptor (LXR), and bile acid signaling pathways. TH modulates hepatic insulin sensitivity, especially important for the suppression of hepatic gluconeogenesis. The role of TH in regulating metabolic pathways has led to several new therapeutic targets for metabolic disorders. Understanding the mechanisms and interactions of the various TH signaling pathways in metabolism will improve our likelihood of identifying effective and selective targets.
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17
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Picou F, Fauquier T, Chatonnet F, Richard S, Flamant F. Deciphering direct and indirect influence of thyroid hormone with mouse genetics. Mol Endocrinol 2014; 28:429-41. [PMID: 24617548 DOI: 10.1210/me.2013-1414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
T3, the active form of thyroid hormone, binds nuclear receptors that regulate the transcription of a large number of genes in many cell types. Unraveling the direct and indirect effect of this hormonal stimulation, and establishing links between these molecular events and the developmental and physiological functions of the hormone, is a major challenge. New mouse genetics tools, notably those based on Cre/loxP technology, are suitable to perform a multiscale analysis of T3 signaling and achieve this task.
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Affiliation(s)
- Frédéric Picou
- Université de Lyon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Claude Bernard Lyon 1, École Normale, Supérieure de Lyon, Institut de Génomique Fonctionnelle de Lyon, Lyon, France
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18
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The emerging role of TRα1 in cardiac repair: potential therapeutic implications. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:481482. [PMID: 24683435 PMCID: PMC3941156 DOI: 10.1155/2014/481482] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 12/31/2013] [Indexed: 02/06/2023]
Abstract
Thyroid hormone (TH) is critical for adapting living organisms to environmental stress. Plasma circulating tri-iodothyronine (T3) levels drop in most disease states and are associated with increased oxidative stress. In this context, T3 levels in plasma appear to be an independent determinant for the recovery of cardiac function after myocardial infarction in patients. Thyroid hormone receptor α1 (TRα1) seems to be crucial in this response; TRα1 accumulates to cell nucleus upon activation of stress induced growth kinase signaling. Furthermore, overexpression of nuclear TRα1 in cardiomyocytes can result in pathological or physiological growth (dual action) in absence or presence of its ligand, respectively. Accordingly, inactivation of TRα1 receptor prevents reactive hypertrophy after myocardial infarction and results in heart failure with increased phospholamban (PLB) expression and marked activation of p38MAPK. In line with this evidence, TH is shown to limit ischemia/reperfusion injury and convert pathologic to physiologic growth after myocardial infarction via TRα1 receptor. TRα1 receptor may prove to be a novel pharmacological target for cardiac repair/regeneration therapies.
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19
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Shi C, Meng Q, Wood DW. Analysis of the roles of mutations in thyroid hormone receptor-β by a bacterial biosensor system. J Mol Endocrinol 2014; 52:55-66. [PMID: 24174637 DOI: 10.1530/jme-13-0108] [Citation(s) in RCA: 5] [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] [Indexed: 11/08/2022]
Abstract
Mutations in thyroid hormone receptors (TRs) often lead to metabolic and developmental disorders, but patients with these mutations are difficult to treat with existing thyromimetic drugs. In this study, we analyzed six clinically observed mutations in the ligand-binding domain of the human TRβ using an engineered bacterial hormone biosensor. Six agonist compounds, including triiodothyronine (T3), thyroxine (T4), 3,5,3'-triiodothyroacetic acid (Triac), GC-1, KB-141, and CO-23, and the antagonist NH-3 were examined for their ability to bind to each of the TRβ mutants. The results indicate that some mutations lead to the loss of ability to bind to native ligands, ranging from several fold to several hundred fold, while other mutations completely abolish the ability to bind to any ligand. Notably, the effect of each ligand on each TRβ mutant in this bacterial system is highly dependent on both the mutation and the ligand; some ligands were bound well by a wide variety of mutants, while other ligands lost their affinity for all but the WT receptor. This study demonstrates the ability of our bacterial system to differentiate agonist compounds from antagonist compounds and shows that one of the TRβ mutations leads to an unexpected increase in antagonist ability relative to other mutations. These results indicate that this bacterial sensor can be used to rapidly determine ligand-binding ability and character for clinically relevant TRβ mutants.
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Affiliation(s)
- Changhua Shi
- Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai 201620, People's Republic of China Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, Ohio 43210, USA
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20
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Bianco AC, Anderson G, Forrest D, Galton VA, Gereben B, Kim BW, Kopp PA, Liao XH, Obregon MJ, Peeters RP, Refetoff S, Sharlin DS, Simonides WS, Weiss RE, Williams GR. American Thyroid Association Guide to investigating thyroid hormone economy and action in rodent and cell models. Thyroid 2014; 24:88-168. [PMID: 24001133 PMCID: PMC3887458 DOI: 10.1089/thy.2013.0109] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND An in-depth understanding of the fundamental principles that regulate thyroid hormone homeostasis is critical for the development of new diagnostic and treatment approaches for patients with thyroid disease. SUMMARY Important clinical practices in use today for the treatment of patients with hypothyroidism, hyperthyroidism, or thyroid cancer are the result of laboratory discoveries made by scientists investigating the most basic aspects of thyroid structure and molecular biology. In this document, a panel of experts commissioned by the American Thyroid Association makes a series of recommendations related to the study of thyroid hormone economy and action. These recommendations are intended to promote standardization of study design, which should in turn increase the comparability and reproducibility of experimental findings. CONCLUSIONS It is expected that adherence to these recommendations by investigators in the field will facilitate progress towards a better understanding of the thyroid gland and thyroid hormone dependent processes.
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Affiliation(s)
- Antonio C. Bianco
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, Florida
| | - Grant Anderson
- Department of Pharmacy Practice and Pharmaceutical Sciences, College of Pharmacy, University of Minnesota Duluth, Duluth, Minnesota
| | - Douglas Forrest
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Valerie Anne Galton
- Department of Physiology and Neurobiology, Dartmouth Medical School, Lebanon, New Hampshire
| | - Balázs Gereben
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Brian W. Kim
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, Florida
| | - Peter A. Kopp
- Division of Endocrinology, Metabolism, and Molecular Medicine, and Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Xiao Hui Liao
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois
| | - Maria Jesus Obregon
- Institute of Biomedical Investigation (IIB), Spanish National Research Council (CSIC) and Autonomous University of Madrid, Madrid, Spain
| | - Robin P. Peeters
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Samuel Refetoff
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois
| | - David S. Sharlin
- Department of Biological Sciences, Minnesota State University, Mankato, Minnesota
| | - Warner S. Simonides
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Roy E. Weiss
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois
| | - Graham R. Williams
- Department of Medicine, Imperial College London, Hammersmith Campus, London, United Kingdom
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21
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Abstract
Thyroid hormones (THs) are important in the development and maintenance of lipid and energy homeostasis. THs act through two closely related TH receptors (TRs α and β), which are conditional transcription factors. Recently, TH analogues or thyromimetics with varying degrees of TR subtype and liver uptake selectivity have been developed. These compounds exert beneficial effects of TH excess states without many undesirable TR-dependent side effects. Several selective TR modulators (STRMs) showed exceptionally promising results in lowering serum cholesterol in preclinical animal models and human clinical studies. Moreover, some first generation STRMs elicit other potentially beneficial effects on obesity, glucose metabolism, and nonalcoholic fatty liver disease (NAFLD). While it was initially thought that STRMs would be an effective long-term therapy to combat elevated cholesterol, possibly in conjunction with another cholesterol-lowering therapy, the statins, three major first generation STRMs failed to progress beyond early phase III human trials. The aim of this review is to discuss how STRMs work, their actions in preclinical animal models and human clinical trials, why they did not progress beyond clinical trials as cholesterol-lowering therapeutics, whether selective TR modulation continues to hold promise for dyslipidemias, and whether members of this drug class could be applied to the treatment of other aspects of metabolic syndrome and human genetic disease.
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Affiliation(s)
- Sunitha Meruvu
- Center for Genomic Medicine, Houston Methodist Research Institute , Houston, Texas
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22
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Saunders NR, Daneman R, Dziegielewska KM, Liddelow SA. Transporters of the blood-brain and blood-CSF interfaces in development and in the adult. Mol Aspects Med 2013; 34:742-52. [PMID: 23506907 DOI: 10.1016/j.mam.2012.11.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 10/04/2012] [Indexed: 02/03/2023]
Abstract
The protective barriers of the brain provide a complex series of physical and chemical obstacles to movement of macromolecules from the periphery into the central nervous system. Studies on these barriers have been focused on two main research areas: (i) anatomical and physiological descriptions of their properties, including during development where functioning barriers are likely to be important for normal neuronal growth; and (ii), investigations of these barriers during disease and attempts at overcoming their defenses in order to deliver drugs to the central nervous system. Both fields are now advanced by the application of molecular gene expression studies of cerebral endothelia (blood vasculature, site of the blood-brain barrier) and choroid plexus epithelia (site of the blood-cerebrospinal fluid barrier) from developing and adult brains, particularly with respect to solute-linked carriers and other transporters. These new techniques provide a wealth of information on the changing nature of transporters at barrier interfaces during normal development and following disease. This review outlines published findings from transcriptome and qPCR studies of expression of genes coding for transporters in these barriers, with a focus on developing brain. The findings clearly support earlier published physiological data describing specific transport mechanisms across barrier interfaces both in the adult and in particular in the developing brain.
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23
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The role of thyroid hormone signaling in the prevention of digestive system cancers. Int J Mol Sci 2013; 14:16240-57. [PMID: 23924944 PMCID: PMC3759909 DOI: 10.3390/ijms140816240] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 07/25/2013] [Accepted: 07/30/2013] [Indexed: 11/17/2022] Open
Abstract
Thyroid hormones play a critical role in the growth and development of the alimentary tract in vertebrates. Their effects are mediated by nuclear receptors as well as the cell surface receptor integrin αVβ3. Systemic thyroid hormone levels are controlled via activation and deactivation by iodothyronine deiodinases in the liver and other tissues. Given that thyroid hormone signaling has been characterized as a major effector of digestive system growth and homeostasis, numerous investigations have examined its role in the occurrence and progression of cancers in various tissues of this organ system. The present review summarizes current findings regarding the effects of thyroid hormone signaling on cancers of the esophagus, stomach, liver, pancreas, and colon. Particular attention is given to the roles of different thyroid hormone receptor isoforms, the novel integrin αVβ3 receptor, and thyroid hormone-related nutrients as possible protective agents and therapeutic targets. Future investigations geared towards a better understanding of thyroid hormone signaling in digestive system cancers may provide preventive or therapeutic strategies to diminish risk, improve outcome and avert recurrence in afflicted individuals.
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24
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Thyroid hormone receptors: the challenge of elucidating isotype-specific functions and cell-specific response. Biochim Biophys Acta Gen Subj 2012; 1830:3900-7. [PMID: 22704954 DOI: 10.1016/j.bbagen.2012.06.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/04/2012] [Accepted: 06/05/2012] [Indexed: 02/06/2023]
Abstract
BACKGROUND Thyroid hormone receptors TRα1, TRβ1 and TRβ2 are broadly expressed and exert a pleiotropic influence on many developmental and homeostatic processes. Extensive genetic studies in mice precisely defined their respective function. SCOPE OF REVIEW The purpose of the review is to discuss two puzzling issues: MAJOR CONCLUSIONS Mouse genetics support a balanced contribution of expression pattern and receptor intrinsic properties in defining the receptor respective functions. The molecular mechanisms sustaining cell specific response remain hypothetical and based on studies performed with other nuclear receptors. GENERAL SIGNIFICANCE The isoform-specificity and cell-specificity questions have many implications for clinical research, drug development, and endocrine disruptor studies. This article is part of a Special Issue entitled Thyroid hormone signalling.
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25
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Chiamolera MI, Sidhaye AR, Matsumoto S, He Q, Hashimoto K, Ortiga-Carvalho TM, Wondisford FE. Fundamentally distinct roles of thyroid hormone receptor isoforms in a thyrotroph cell line are due to differential DNA binding. Mol Endocrinol 2012; 26:926-39. [PMID: 22570333 DOI: 10.1210/me.2011-1290] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Thyroid hormones have a profound influence on human development and disease. The hypothalamic-pituitary-thyroid axis involves finely tuned feedback mechanisms to maintain thyroid hormone (TH) levels. Despite the important role of TH-negative feedback in regulating this axis, the mechanism by which this occurs is not clearly defined. Previous in vivo studies suggest separate roles for the two thyroid hormone receptor isoforms, THRA and THRB, in this axis. We performed studies using a unique pituitary thyrotroph cell line (TαT1.1) to determine the relative roles of THRA and THRB in the regulation of Tshb. Using chromatin immunoprecipitation assays, we found that THRB, not THRA, bound to the Tshb promoter. By selectively depleting THRB, THRA, or both THRA and THRB in TαT1.1 cells, we found that simultaneous knockdown of both THRB and THRA abolished T(3)-mediated down-regulation of Tshb at concentrations as high as 100 nm T(3). In contrast, THRA knockdown alone had no effect on T(3)-negative regulation, whereas THRB knockdown alone abolished T(3)-mediated down-regulation of Tshb mRNA levels at 10 nm but not 100 nm T(3) concentrations. Interestingly, chromatin immunoprecipitation assays showed that THRA becomes enriched on the Tshb promoter after knockdown of THRB. Thus, a likely mechanism for the differential effects of THR isoforms on Tshb may be based on their differential DNA-binding affinity to the promoter.
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26
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Molecular characterisation of transport mechanisms at the developing mouse blood-CSF interface: a transcriptome approach. PLoS One 2012; 7:e33554. [PMID: 22457777 PMCID: PMC3310074 DOI: 10.1371/journal.pone.0033554] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 02/12/2012] [Indexed: 11/19/2022] Open
Abstract
Exchange mechanisms across the blood-cerebrospinal fluid (CSF) barrier in the choroid plexuses within the cerebral ventricles control access of molecules to the central nervous system, especially in early development when the brain is poorly vascularised. However, little is known about their molecular or developmental characteristics. We examined the transcriptome of lateral ventricular choroid plexus in embryonic day 15 (E15) and adult mice. Numerous genes identified in the adult were expressed at similar levels at E15, indicating substantial plexus maturity early in development. Some genes coding for key functions (intercellular/tight junctions, influx/efflux transporters) changed expression during development and their expression patterns are discussed in the context of available physiological/permeability results in the developing brain. Three genes: Secreted protein acidic and rich in cysteine (Sparc), Glycophorin A (Gypa) and C (Gypc), were identified as those whose gene products are candidates to target plasma proteins to choroid plexus cells. These were investigated using quantitative- and single-cell-PCR on plexus epithelial cells that were albumin- or total plasma protein-immunopositive. Results showed a significant degree of concordance between plasma protein/albumin immunoreactivity and expression of the putative transporters. Immunohistochemistry identified SPARC and GYPA in choroid plexus epithelial cells in the embryo with a subcellular distribution that was consistent with transport of albumin from blood to cerebrospinal fluid. In adult plexus this pattern of immunostaining was absent. We propose a model of the cellular mechanism in which SPARC and GYPA, together with identified vesicle-associated membrane proteins (VAMPs) may act as receptors/transporters in developmentally regulated transfer of plasma proteins at the blood-CSF interface.
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27
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Yuan C, Lin JZH, Sieglaff DH, Ayers SD, Denoto-Reynolds F, Baxter JD, Webb P. Identical gene regulation patterns of T3 and selective thyroid hormone receptor modulator GC-1. Endocrinology 2012; 153:501-11. [PMID: 22067320 PMCID: PMC3249679 DOI: 10.1210/en.2011-1325] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Synthetic selective thyroid hormone (TH) receptor (TR) modulators (STRM) exhibit beneficial effects on dyslipidemias in animals and humans and reduce obesity, fatty liver, and insulin resistance in preclinical animal models. STRM differ from native TH in preferential binding to the TRβ subtype vs. TRα, increased uptake into liver, and reduced uptake into other tissues. However, selective modulators of other nuclear receptors exhibit important gene-selective actions, which are attributed to differential effects on receptor conformation and dynamics and can have profound influences in animals and humans. Although there are suggestions that STRM may exhibit such gene-specific actions, the extent to which they are actually observed in vivo has not been explored. Here, we show that saturating concentrations of the main active form of TH, T(3), and the prototype STRM GC-1 induce identical gene sets in livers of euthyroid and hypothyroid mice and a human cultured hepatoma cell line that only expresses TRβ, HepG2. We find one case in which GC-1 exhibits a modest gene-specific reduction in potency vs. T(3), at angiopoietin-like factor 4 in HepG2. Investigation of the latter effect confirms that GC-1 acts through TRβ to directly induce this gene but this gene-selective activity is not related to unusual T(3)-response element sequence, unlike previously documented promoter-selective STRM actions. Our data suggest that T(3) and GC-1 exhibit almost identical gene regulation properties and that gene-selective actions of GC-1 and similar STRM will be subtle and rare.
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Affiliation(s)
- Chaoshen Yuan
- Methodist Hospital Research Institute, F8-045, 6565 Fannin Street, Houston, Texas 77030, USA
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28
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Sayre NL, Lechleiter JD. Fatty acid metabolism and thyroid hormones. CURRENT TRENDS IN ENDOCRINOLOGY 2012; 6:65-76. [PMID: 24436572 PMCID: PMC3891511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The importance of thyroid hormone signaling in the acute regulation of metabolic activity has been recognized for decades. Slowly, the underlying mechanisms responsible for this activity are being elucidated. A prominent characteristic of thyroid signaling is rapid increases in oxygen consumption and ATP production. This discovery implicated a non-genomic regulation of mitochondrial metabolism by thyroid hormones. Another important clue came from the discovery that thyroid hormones stimulated fatty acid oxidation (FAO) in a variety of tissues in a receptor-dependent, but transcriptional-independent manner. Recently, key linkages between thyroid hormone signaling and specific mitochondrial-targeted pathways have been discovered. This review focuses on the molecular mechanisms by which mitochondrial FAO can be increased through thyroid hormone signaling. The roles of both the full-length and shortened mitochondrial isoforms of thyroid hormone receptor will be discussed. Additionally, the impact of thyroid hormone signaling on dyslipidemias such as obesity, type II diabetes, and fatty liver disease will be considered.
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Affiliation(s)
- Naomi L Sayre
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, South Texas Research Facility Neuroscience Center, 8403 Floyd Curl Drive, San Antonio, TX 78229-3904, USA
| | - James D Lechleiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, South Texas Research Facility Neuroscience Center, 8403 Floyd Curl Drive, San Antonio, TX 78229-3904, USA
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29
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Chatonnet F, Picou F, Fauquier T, Flamant F. Thyroid hormone action in cerebellum and cerebral cortex development. J Thyroid Res 2011; 2011:145762. [PMID: 21765985 PMCID: PMC3134109 DOI: 10.4061/2011/145762] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 04/09/2011] [Indexed: 01/30/2023] Open
Abstract
Thyroid hormones (TH, including the prohormone thyroxine (T4) and its active deiodinated derivative 3,3′,5-triiodo-L-thyronine (T3)) are important regulators of vertebrates neurodevelopment. Specific transporters and deiodinases are required to ensure T3 access to the developing brain. T3 activates a number of differentiation processes in neuronal and glial cell types by binding to nuclear receptors, acting directly on transcription. Only few T3 target genes are currently known. Deeper investigations are urgently needed, considering that some chemicals present in food are believed to interfere with T3 signaling with putative neurotoxic consequences.
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Affiliation(s)
- Fabrice Chatonnet
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, Université de Lyon, UMR CNRS 5242, 46 allée d'Italie, 69364 Lyon Cedex 07, France
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30
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Abstract
Selective thyromimetics are synthetic analogs of thyroid hormones with tissue-specific thyroid hormone actions. Tissue selectivity is partly mediated by selectivity for the thyroid hormone receptor-β isoform, but is also enhanced by tissue-selective uptake. Several preclinical animal models and recent human clinical trials have provided sound evidence that thyromimetics can serve as pharmacological tools to improve serum lipids without affecting heart rate. Thyromimetics consistently and efficiently lowered low-density lipoprotein cholesterol and lipoprotein (a) plasma levels without positive chronotropic effects. Most importantly, thyromimetics had a synergistic action when used in addition to 3-hydroxy-3-methylglutaryl CoA reductase inhibitors. Animal data have further suggested that thyromimetics might be useful in the treatment of obesity, hepatic steatosis and atherosclerosis. However, only long-term phase III clinical trials will tell if the observed lipid lowering effects of thyromimetics will improve cardiovascular outcome in humans, too. At the moment, the treatment of dyslipidemia seems to be the major indication for the therapeutic use of thyromimetics, which are now rapidly moving from bench to bed-side.
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Affiliation(s)
- Ivan Tancevski
- Department of Internal Medicine I, Innsbruck Medical University, Innsbruck, Austria.
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Affiliation(s)
- Miriam O Ribeiro
- Department of Biological Science, Biological and Health Science Center, MacKenzie Presbiterian University, Sao Paulo SP 01302, Brazil
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