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Major E, Győry F, Horváth D, Keller I, Tamás I, Uray K, Fülöp P, Lontay B. Smoothelin-Like Protein 1 Regulates Development and Metabolic Transformation of Skeletal Muscle in Hyperthyroidism. Front Endocrinol (Lausanne) 2021; 12:751488. [PMID: 34675885 PMCID: PMC8524136 DOI: 10.3389/fendo.2021.751488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 09/14/2021] [Indexed: 12/17/2022] Open
Abstract
Hyperthyroidism triggers a glycolytic shift in skeletal muscle (SKM) by altering the expression of metabolic proteins, which is often accompanied by peripheral insulin resistance. Our previous results show that smoothelin-like protein 1 (SMTNL1), a transcriptional co-regulator, promotes insulin sensitivity in SKM. Our aim was to elucidate the role of SMTNL1 in SKM under physiological and pathological 3,3',5-Triiodo-L-thyronine (T3) concentrations. Human hyper- and euthyroid SKM biopsies were used for microarray analysis and proteome profiler arrays. Expression of genes related to energy production, nucleic acid- and lipid metabolism was changed significantly in hyperthyroid samples. The phosphorylation levels and activity of AMPKα2 and JNK were increased by 15% and 23%, respectively, in the hyperthyroid samples compared to control. Moreover, SMTNL1 expression showed a 6-fold decrease in the hyperthyroid samples and in T3-treated C2C12 cells. Physiological and supraphysiological concentrations of T3 were applied on differentiated C2C12 cells upon SMTNL1 overexpression to assess the activity and expression level of the elements of thyroid hormone signaling, insulin signaling and glucose metabolism. Our results demonstrate that SMTNL1 selectively regulated TRα expression. Overexpression of SMTNL1 induced insulin sensitivity through the inhibition of JNK activity by 40% and hampered the non-genomic effects of T3 by decreasing the activity of ERK1/2 through PKCδ. SMTNL1 overexpression reduced IRS1 Ser307 and Ser612 phosphorylation by 52% and 53%, respectively, in hyperthyroid model to restore the normal responsiveness of glucose transport to insulin. SMTNL1 regulated glucose phosphorylation and balances glycolysis and glycogen synthesis via the downregulation of hexokinase II by 1.3-fold. Additionally, mitochondrial respiration and glycolysis were measured by SeaHorse analysis to determine cellular metabolic function/phenotype of our model system in real-time. T3 overload strongly increased the rate of acidification and a shift to glycolysis, while SMTNL1 overexpression antagonizes the T3 effects. These lines of evidence suggest that SMTNL1 potentially prevents hyperthyroidism-induced changes in SKM, and it holds great promise as a novel therapeutic target in insulin resistance.
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Affiliation(s)
- Evelin Major
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ferenc Győry
- Department of Surgery, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dániel Horváth
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ilka Keller
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Tamás
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Karen Uray
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Fülöp
- Department of Internal Medicine, Division of Metabolism, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Beáta Lontay
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Anyetei-Anum CS, Evans RM, Back AM, Roggero VR, Allison LA. Acetylation modulates thyroid hormone receptor intracellular localization and intranuclear mobility. Mol Cell Endocrinol 2019; 495:110509. [PMID: 31319097 PMCID: PMC6708479 DOI: 10.1016/j.mce.2019.110509] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/05/2019] [Accepted: 07/14/2019] [Indexed: 01/07/2023]
Abstract
The thyroid hormone receptor (TR) undergoes nucleocytoplasmic shuttling, but is primarily nuclear-localized and mediates expression of genes involved in development and homeostasis. Given the proximity of TR acetylation and sumoylation sites to nuclear localization (NLS) and nuclear export signals, we investigated their role in regulating intracellular localization. The nuclear/cytosolic fluorescence ratio (N/C) of fluorescent protein-tagged acetylation mimic, nonacetylation mimic, and sumoylation-deficient TR was quantified in transfected mammalian cells. While nonacetylation mimic and sumoylation-deficient TRs displayed wild-type N/C, the acetylation mimic's N/C was significantly lower. Importins that interact with wild-type TR also interact with acetylation and nonacetylation mimics, suggesting factors other than reduced importin binding alter nuclear localization. FRAP analysis showed wild-type intranuclear dynamics of acetylation mimic and sumoylation-deficient TRs, whereas the nonacetylation mimic had significantly reduced mobility and transcriptional activity. Acetyltransferase CBP/p300 inhibition enhanced TR's nuclear localization, further suggesting that nonacetylation correlates with nuclear retention, while acetylation promotes cytosolic localization.
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Affiliation(s)
- Cyril S Anyetei-Anum
- Department of Biology, College of William and Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23187, USA
| | - Rochelle M Evans
- Department of Biology, College of William and Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23187, USA
| | - Amanda M Back
- Department of Biology, College of William and Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23187, USA
| | - Vincent R Roggero
- Department of Biology, College of William and Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23187, USA
| | - Lizabeth A Allison
- Department of Biology, College of William and Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23187, USA.
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Oster M, Gerlinger C, Heide K, Just F, Borgelt L, Wolf P, Polley C, Vollmar B, Muráni E, Ponsuksili S, Wimmers K. Lower dietary phosphorus supply in pigs match both animal welfare aspects and resource efficiency. AMBIO 2018; 47:20-29. [PMID: 29159450 PMCID: PMC5722738 DOI: 10.1007/s13280-017-0969-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Dietary phosphorus frequently exceeds age-specific requirements and pig manure often contains high phosphorus load which causes environmental burden at regional scales. Therefore, feeding strategies towards improved phosphorus efficiency and reduced environmental phosphorus load have to be developed. A 5-week feeding trial was conducted: piglets received medium, lower (-25%), or higher (+25%) amounts of phosphorus and calcium. Dietary responses were reflected by performance parameters, bone characteristics, and molecular data retrieved from serum, intestinal mucosa, and kidney cortex (p < 0.05). Transcripts associated with vitamin D hydroxylation (Cyp24A1, Cyp27A1, Cyp27B1) were regulated by diet at local tissue sites. Low-fed animals showed attempts to maintain mineral homoeostasis via intrinsic mechanisms, whereas the high-fed animals adapted at the expense of growth and development. Results suggest that a diet containing low phosphorus and calcium levels might be useful to improve resource efficiency and to reduce phosphorus losses along the agricultural value chain.
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Affiliation(s)
- Michael Oster
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Christian Gerlinger
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
- University of Rostock, Justus-von-Liebig-Weg 6b, 18059 Rostock, Germany
| | - Kaja Heide
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
- LUFA-ITL GmbH, Dr.-Hell-Str. 6, 24107 Kiel, Germany
| | - Franziska Just
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Luisa Borgelt
- Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig-Weg 6b, 18059 Rostock, Germany
| | - Petra Wolf
- Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig-Weg 6b, 18059 Rostock, Germany
| | - Christian Polley
- University of Rostock, Justus-von-Liebig-Weg 6b, 18059 Rostock, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, University Medical Center Rostock, Schillingallee 69a, 18057 Rostock, Germany
| | - Eduard Muráni
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Siriluck Ponsuksili
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Klaus Wimmers
- Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
- Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig-Weg 6b, 18059 Rostock, Germany
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Bargi-Souza P, Goulart-Silva F, Nunes MT. Novel aspects of T 3 actions on GH and TSH synthesis and secretion: physiological implications. J Mol Endocrinol 2017; 59:R167-R178. [PMID: 28951438 DOI: 10.1530/jme-17-0068] [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] [Received: 09/04/2017] [Accepted: 09/26/2017] [Indexed: 12/27/2022]
Abstract
Thyroid hormones (THs) classically regulate the gene expression by transcriptional mechanisms. In pituitary, the encoding genes for growth hormone (GH) and thyroid-stimulating hormone (TSH) are examples of genes regulated by triiodothyronine (T3) in a positive and negative way, respectively. Recent studies have shown a rapid adjustment of GH and TSH synthesis/secretion induced by T3 posttranscriptional actions. In somatotrophs, T3 promotes an increase in Gh mRNA content, poly(A) tail length and binding to the ribosome, associated with a rearrangement of actin cytoskeleton. In thyrotrophs, T3 reduces Tshb mRNA content, poly(A) tail length and its association with the ribosome. In parallel, it promotes a redistribution of TSH secretory granules to more distal regions of the cell periphery, indicating a rapid effect of T3 inhibition of TSH secretion. T3 was shown to affect the content of tubulin and the polymerization of actin and tubulin cytoskeletons in the whole anterior pituitary gland, and to increase intracellular alpha (CGA) content. This review summarizes genomic and non-genomic/posttranscriptional actions of TH on the regulation of several steps of GH and TSH synthesis and secretion. These distinct mechanisms induced by T3 can occur simultaneously, even though non-genomic effects are promptly elicited and precede the genomic actions, coexisting in a functional network within the cells.
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Affiliation(s)
| | | | - M T Nunes
- Department of Physiology and Biophysics of the Institute of Biomedical SciencesUniversity of São Paulo, São Paulo, SP, Brazil
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Wadosky KM, Berthiaume JM, Tang W, Zungu M, Portman MA, Gerdes AM, Willis MS. MuRF1 mono-ubiquitinates TRα to inhibit T3-induced cardiac hypertrophy in vivo. J Mol Endocrinol 2016; 56:273-90. [PMID: 26862156 PMCID: PMC5453669 DOI: 10.1530/jme-15-0283] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 02/05/2016] [Indexed: 12/31/2022]
Abstract
Thyroid hormone (TH) is recognized for its role in cellular metabolism and growth and participates in homeostasis of the heart. T3 activates pro-survival pathways including Akt and mTOR. Treatment with T3 after myocardial infarction is cardioprotective and promotes elements of physiological hypertrophic response after cardiac injury. Although T3 is known to benefit the heart, very little about its regulation at the molecular level has been described to date. The ubiquitin proteasome system (UPS) regulates nuclear hormone receptors such as estrogen, progesterone, androgen, and glucocorticoid receptors by both degradatory and non-degradatory mechanisms. However, how the UPS regulates T3-mediated activity is not well understood. In this study, we aim to determine the role of the muscle-specific ubiquitin ligase muscle ring finger-1 (MuRF1) in regulating T3-induced cardiomyocyte growth. An increase in MuRF1 expression inhibits T3-induced physiological cardiac hypertrophy, whereas a decrease in MuRF1 expression enhances T3's activity both in vitro and in cardiomyocytes in vivo MuRF1 interacts directly with TRα to inhibit its activity by posttranslational ubiquitination in a non-canonical manner. We then demonstrated that a nuclear localization apparatus that regulates/inhibits nuclear receptors by sequestering them within a subcompartment of the nucleus was necessary for MuRF1 to inhibit T3 activity. This work implicates a novel mechanism that enhances the beneficial T3 activity specifically within the heart, thereby offering a potential target to enhance cardiac T3 activity in an organ-specific manner.
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Affiliation(s)
- Kristine M Wadosky
- Department of Pathology and Laboratory MedicineUniversity of North Carolina, Chapel Hill, NC, USA
| | - Jessica M Berthiaume
- Department of Physiology & BiophysicsCase Western Reserve University, Cleveland, OH, USA
| | - Wei Tang
- Department of Pathology and Laboratory MedicineUniversity of North Carolina, Chapel Hill, NC, USA
| | - Makhosi Zungu
- Department of Pathology and Laboratory MedicineUniversity of North Carolina, Chapel Hill, NC, USA
| | - Michael A Portman
- Department of PediatricsCenter for Developmental Therapeutics, Seattle Children's Research Institute, University of Washington, Seattle, WA, USA
| | - A Martin Gerdes
- New York Institute of TechnologyCollege of Osteopathic Medicine, New York, NY, USA
| | - Monte S Willis
- Department of Pathology and Laboratory MedicineUniversity of North Carolina, Chapel Hill, NC, USA McAllister Heart InstituteUniversity of North Carolina, Chapel Hill, NC, USA
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Sabatino L, Iervasi G, Pingitore A. Thyroid hormone and heart failure: from myocardial protection to systemic regulation. Expert Rev Cardiovasc Ther 2014; 12:1227-36. [PMID: 25220579 DOI: 10.1586/14779072.2014.957674] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Heart failure (HF) is an intriguing model of chronic disease. It starts as an organ disorder developing, in its progression, into a systemic disease in which the dysfunction of other organs plays a relevant clinical and prognostic impact. Furthermore, continuous activation of systemic pathways plays a role in disease progression, switching their effect from protective to harmful. In this combination of organ dysfunction and systemic derangement, thyroid hormone (TH) have an important regulative impact from cardiovascular to systemic level and from molecular/cellular processes to clinical setting. Whether it is accepted to include TH and thyroid stimulating hormone assessment in the clinical HF course, the next challenge will be to ascertain the benefit of TH replacement therapy in HF patients, taking into consideration the type of hormone to administer, dosage and treatment schedule.
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Affiliation(s)
- Laura Sabatino
- Clinical Physiology Institute, CNR, Via Moruzzi 1, 56124, Pisa, Italy
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Brunelle M, Fayad T, Langlois MF. Degradation of thyroid hormone receptor beta 1: existence of stable and unstable forms. Thyroid 2011; 21:311-8. [PMID: 21323586 DOI: 10.1089/thy.2009.0363] [Citation(s) in RCA: 7] [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 The degradation of many nuclear receptors is controlled by ligand-binding and mediated by the ubiquitin-proteasome pathway. However, the mechanisms implicated in thyroid hormone receptor (TR) degradation remain unclear. Our objective was to define the kinetics, mechanisms, and sub-cellular fractions involved in TRs degradation. METHODS We used pulse-chase analyses, time-course experiments carried out in presence of cycloheximide (to inhibit new protein synthesis), and biochemical fractionation with Western blot analyses to determine the kinetics of the degradation of the TRβ isoform, TRβ1, in transiently transfected QBI-HEK 293A cells. RESULTS We observed that TRβ1 degradation is mediated by the proteasome pathway. Also, the kinetics of TRβ1 degradation is atypical due to the co-existence of more than one TRβ1 population, located in different cellular compartments and having different stability profiles. Moreover, TRβ1 degradation was unaffected by a mutation in its putative PEST motif, which confers turnover of other proteins. CONCLUSION Our findings introduce novel evidence suggesting that stable and unstable forms of TRβ1, which might have distinct functions, co-exist in cells.
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Affiliation(s)
- Mylène Brunelle
- Département de Médecine, Service d'endocrinologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Canada
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9
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Bondzi C, Brunner AM, Munyikwa MR, Connor CD, Simmons AN, Stephens SL, Belt PA, Roggero VR, Mavinakere MS, Hinton SD, Allison LA. Recruitment of the oncoprotein v-ErbA to aggresomes. Mol Cell Endocrinol 2011; 332:196-212. [PMID: 21075170 PMCID: PMC4634111 DOI: 10.1016/j.mce.2010.10.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Accepted: 10/14/2010] [Indexed: 02/01/2023]
Abstract
Aggresome formation, a cellular response to misfolded protein aggregates, is linked to cancer and neurodegenerative disorders. Previously we showed that Gag-v-ErbA (v-ErbA), a retroviral variant of the thyroid hormone receptor (TRα1), accumulates in and sequesters TRα1 into cytoplasmic foci. Here, we show that foci represent v-ErbA targeting to aggresomes. v-ErbA colocalizes with aggresomal markers, proteasomes, hsp70, HDAC6, and mitochondria. Foci have hallmark characteristics of aggresomes: formation is microtubule-dependent, accelerated by proteasome inhibitors, and they disrupt intermediate filaments. Proteasome-mediated degradation is critical for clearance of v-ErbA and T(3)-dependent TRα1 clearance. Our studies highlight v-ErbA's complex mode of action: the oncoprotein is highly mobile and trafficks between the nucleus, cytoplasm, and aggresome, carrying out distinct activities within each compartment. Dynamic trafficking to aggresomes contributes to the dominant negative activity of v-ErbA and may be enhanced by the viral Gag sequence. These studies provide insight into novel modes of oncogenesis across multiple cellular compartments.
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Affiliation(s)
- Cornelius Bondzi
- Department of Biological Sciences, Hampton University, Hampton, VA 23668
| | - Abigail M. Brunner
- Department of Biology, College of William and Mary, Williamsburg, VA 23187
| | | | - Crystal D. Connor
- Department of Biological Sciences, Hampton University, Hampton, VA 23668
| | - Alicia N. Simmons
- Department of Biological Sciences, Hampton University, Hampton, VA 23668
| | | | - Patricia A. Belt
- Department of Biological Sciences, Hampton University, Hampton, VA 23668
| | - Vincent R. Roggero
- Department of Biology, College of William and Mary, Williamsburg, VA 23187
| | | | - Shantá D. Hinton
- Department of Biology, College of William and Mary, Williamsburg, VA 23187
| | - Lizabeth A. Allison
- Department of Biology, College of William and Mary, Williamsburg, VA 23187
- Corresponding author: Lizabeth A. Allison, Department of Biology, College of William and Mary, Integrated Science Center Room 3035B, 540 Landrum Drive, Williamsburg, VA 23187, Tele: 757-221-2232, Fax: 757-221-6483,
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10
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Translational potential of thyroid hormone and its analogs. J Mol Cell Cardiol 2011; 51:506-11. [PMID: 21215270 DOI: 10.1016/j.yjmcc.2010.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 11/04/2010] [Accepted: 12/21/2010] [Indexed: 10/18/2022]
Abstract
Thyroid hormone has unique properties affecting the heart, and the vasculature and cholesterol metabolism. There is interest in using thyromimetic agents as possible treatment options for heart failure based on data demonstrating the ability of these agents to improve systolic and diastolic left ventricular function as well as their vasodilatory action. The inverse relationship between heart failure severity and serum triiodothyronine (T3) levels has also been interpreted by some as an indication that thyroid hormone therapy might be useful. In the 1950s, investigators began developing thyroid hormone analogs that could lower cholesterol, that selectively bind to β1-type nuclear thyroid hormone receptors (TR), which are responsible for cholesterol-lowering activity, without activating α1-type receptors in the heart. The identification of 3,5-diiodothyropropionic acid (DITPA) that binds to both α- and β-type TRs with relatively low affinity was unique in that this analog improves left ventricular function in heart failure as well as lowers cholesterol. The aim of this review is to summarize information known about the interactions between thyroid hormones and the cardiovascular system, and the potential therapeutic effects of thyroid analogs in chronic heart disease. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."
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Wang YY, Morimoto S, Du CK, Lu QW, Zhan DY, Tsutsumi T, Ide T, Miwa Y, Takahashi-Yanaga F, Sasaguri T. Up-regulation of type 2 iodothyronine deiodinase in dilated cardiomyopathy. Cardiovasc Res 2010; 87:636-46. [PMID: 20453157 DOI: 10.1093/cvr/cvq133] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AIMS Thyroid hormone (TH) has prominent effects on the heart, and hyperthyroidism is occasionally found to be a cause of dilated cardiomyopathy (DCM). We aim to explore the potential role of TH in the pathogenesis of DCM. METHODS AND RESULTS The pathophysiological role of TH in the heart was investigated using a knock-in mouse model of inherited DCM with a deletion mutation DeltaK210 in the cardiac troponin T gene. Serum tri-iodothyronine (T(3)) levels showed no significant difference between wild-type (WT) and DCM mice, whereas cardiac T(3) levels in DCM mice were significantly higher than those in WT mice. Type 2 iodothyronine deiodinase (Dio2), which produces T(3) from thyroxin, was up-regulated in the DCM mice hearts. The cAMP levels were increased in DCM mice hearts, suggesting that transcriptional up-regulation of Dio2 gene is mediated through the evolutionarily conserved cAMP-response element site in its promoter. Propylthiouracil (PTU), an anti-thyroid drug, prevented the hypertrophic remodelling of the heart in DCM mice and improved their cardiac function and life expectancy. Akt and p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation increased in the DCM mice hearts and PTU treatment significantly reduced the phosphorylation levels, strongly suggesting that Dio2 up-regulation is involved in cardiac remodelling in DCM through activating the TH-signalling pathways involving Akt and p38 MAPK. Dio2 gene expression was also markedly up-regulated in the mice hearts developing similar eccentric hypertrophy after myocardial infarction. CONCLUSION Local hyperthyroidism via transcriptional up-regulation of the Dio2 gene may be an important underlying mechanism for the hypertrophic cardiac remodelling in DCM.
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MESH Headings
- Animals
- Antithyroid Agents/pharmacology
- Cardiomyopathy, Dilated/drug therapy
- Cardiomyopathy, Dilated/enzymology
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/physiopathology
- Cells, Cultured
- Cyclic AMP/metabolism
- Disease Models, Animal
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Enzymologic
- Iodide Peroxidase/genetics
- Iodide Peroxidase/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Mutation
- Myocardium/enzymology
- Oligonucleotide Array Sequence Analysis
- Phosphorylation
- Propylthiouracil/pharmacology
- Proto-Oncogene Proteins c-akt/metabolism
- Transcription, Genetic
- Triiodothyronine/metabolism
- Troponin T/genetics
- Troponin T/metabolism
- Up-Regulation
- Ventricular Remodeling/drug effects
- p38 Mitogen-Activated Protein Kinases/metabolism
- Iodothyronine Deiodinase Type II
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Affiliation(s)
- Yuan-Yuan Wang
- Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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12
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Bonamy GM, Allison LA. Oncogenic conversion of the thyroid hormone receptor by altered nuclear transport. NUCLEAR RECEPTOR SIGNALING 2006; 4:e008. [PMID: 16741566 PMCID: PMC1472669 DOI: 10.1621/nrs.04008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Accepted: 02/16/2006] [Indexed: 01/14/2023]
Abstract
Nuclear receptors (NRs) are transcription factors whose activity is modulated by ligand binding. These receptors are at the core of complex signaling pathways and act as integrators of many cellular signals. In the last decade our understanding of NRs has greatly evolved. In particular, regulation of NR subcellular dynamics has emerged as central to their activity. Research on the subcellular distribution of the thyroid hormone receptor (TR) has revealed new dimensions in the complexity of NR regulation, and points to the possibility that NR mislocalization plays a key role in oncogenesis. For many years, TR was thought to reside exclusively in the nucleus. It is now known that TR is a dynamic protein that shuttles between the nucleus and cytoplasm. TR is localized to the nucleus in a phosphorylated form, suggesting that compartment-specific phosphorylation mediates cross-talk between multiple cell signaling pathways. The oncoprotein v-ErbA, a viral-derived dominant negative variant of TR is actively exported to the cytoplasm by the CRM1 export receptor. Strikingly, the oncoprotein causes mislocalization of cellular TR and some of its coactivators by direct interaction. Here, we offer some perspectives on the role of subcellular trafficking in the oncogenic conversion of TR, and propose a new model for oncoprotein dominant negative activity.
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Monden T, Nakajima Y, Hashida T, Ishii S, Tomaru T, Shibusawa N, Hashimoto K, Satoh T, Yamada M, Mori M, Kasai K. Expression of thyroid hormone receptor isoforms down-regulated by thyroid hormone in human medulloblastoma cells. Endocr J 2006; 53:181-7. [PMID: 16618975 DOI: 10.1507/endocrj.53.181] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The role of thyroid hormone (T3) in the regulation of growth and development of the central nervous system including the cerebellum has been well established. However, the effects of thyroid hormone on malignant tumors derived from the cerebellum remain poorly understood. Our analysis mainly focused on expression levels of TR isoforms and the effects of thyroid hormone in human medulloblastoma HTB-185 cells. Northern blot analysis revealed TRalpha2 mRNA but not TRalpha1, beta1 or beta2 mRNA in the cell. The TRalpha1 and TRbeta1 mRNAs were detected only by RT-PCR method and TRbeta2 was not expressed. Incubation of T3 for 24 h decreased TRalpha1, TRalpha2 and TRbeta1 mRNA. Addition of actinomycin D caused an acute increase in the basal TR mRNA levels and the rate of decrease of all kinds of TR isoform mRNA was accelerated in the T3-treated groups compared to controls, indicating that the stability of TR mRNA was affected by T3. Incubation with cycloheximide also blocked a decrease in TR mRNA levels in the T3-treated HTB-185 cells suggesting that down-regulation of TR mRNA required the synthesis of new protein. Our data provide novel evidence for the expression of TRs down-regulated by T3 in HTB-185 cells, suggesting that TR expression is post-transcriptionally regulated by T3 at the level of RNA stability.
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Affiliation(s)
- Tsuyoshi Monden
- Department of Endocrinology and Metabolism, Dokkyo University School of Medicine, Tochigi, Japan
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Minamisawa S, Uemura N, Sato Y, Yokoyama U, Yamaguchi T, Inoue K, Nakagome M, Bai Y, Hori H, Shimizu M, Mochizuki S, Ishikawa Y. Post-transcriptional downregulation of sarcolipin mRNA by triiodothyronine in the atrial myocardium. FEBS Lett 2006; 580:2247-52. [PMID: 16566928 DOI: 10.1016/j.febslet.2006.03.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 03/09/2006] [Indexed: 10/24/2022]
Abstract
Thyroid hormone-mediated positive cardiotropic effects are differently regulated between the atria and ventricles. This regulation is, at least in part, dependent on sarcoplasmic reticulum (SR) proteins. Sarcolipin, a homologue of phospholamban, has been recently identified as an atrium-specific SR protein. The expression of sarcolipin mRNA was significantly decreased in the atria of mice with hyperthyroidism and in 3,5,3'-triiodo-l-thyronine-treated neonatal rat atrial myocytes. Promoter activity and mRNA stability analyses revealed that thyroid hormone post-transcriptionally down regulated the expression of sarcolipin mRNA. The atrium-specific effect of thyroid hormone may occur in part through the regulation of atrial sarcolipin gene expression.
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Affiliation(s)
- Susumu Minamisawa
- Department of Physiology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
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15
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Kenessey A, Sullivan EA, Ojamaa K. Nuclear localization of protein kinase C-α induces thyroid hormone receptor-α1 expression in the cardiomyocyte. Am J Physiol Heart Circ Physiol 2006; 290:H381-9. [PMID: 16155104 DOI: 10.1152/ajpheart.00576.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Maladaptive cardiac hypertrophy results in phenotypic changes in several genes that are thyroid hormone responsive, suggesting that thyroid hormone receptor (TR) function may be altered by cellular kinases, including protein kinase C (PKC) isozymes that are activated in pathological hypertrophy. To investigate the role of PKC signaling in regulating TR function, cultured neonatal rat ventricular myocytes were transduced with adenovirus (Ad) expressing wild-type (wt) or kinase-inactive (dn) PKCα or constitutively active (ca) PKCδ and PKCε. Overexpression of wtPKCα, but not caPKCδ or caPKCε, induced a 28-fold increase ( P < 0.001) in TRα1 protein in the nuclear compartment and a smaller increase in the cytosol. Furthermore, TRα1 mRNA was increased 55-fold ( P < 0.001). This effect of PKCα was dependent on its kinase activity because dnPKCα was without effect. Phorbol 12-myristate 13-acetate (PMA) induced nuclear translocation of endogenous PKCα and Ad-wtPKCα concomitantly with an increase in nuclear TRα1 protein. In contrast, PMA-induced nuclear translocation of dnPKCα resulted in a decrease of TRα1. The increase in TRα1 protein in Ad-wtPKCα-transduced cardiomyocytes was not the result of a reduced rate of protein degradation, nor was the half-life of TRα1 mRNA prolonged, suggesting a PKCα-mediated effect on TRα transcription. Although phosphorylation of ERK1/2 was increased in Ad-wtPKCα-transduced cells, inhibition of phospho-ERK did not change TRα1 expression. PKCα overexpression in cardiomyocytes caused marked repression of triiodothyronine (T3)-responsive genes, α-myosin heavy chain, and the sarcoplasmic reticulum calcium-activated adenosinetriphosphatase SERCA2. Treatment with T3for 4 h resulted in significant reductions of PKCα in nuclear and cytosolic compartments, and decreased TRα1 mRNA and protein, with normalization of phenotype. These results implicate PKCα as a regulator of TR function and suggest that nuclear localization of PKCα may control transcription of the TRα gene, and consequently, affect cardiac phenotype.
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Affiliation(s)
- Agnes Kenessey
- Institute for Medical Research, North Shore-LIJ Health System, 350 Community Dr., Manhasset, NY 11030, USA
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16
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Lin X, Sakuragi T, Metz CN, Ojamaa K, Skopicki HA, Wang P, Al-Abed Y, Miller EJ. MACROPHAGE MIGRATION INHIBITORY FACTOR WITHIN THE ALVEOLAR SPACES INDUCES CHANGES IN THE HEART DURING LATE EXPERIMENTAL SEPSIS. Shock 2005; 24:556-63. [PMID: 16317387 DOI: 10.1097/01.shk.0000183238.70374.a8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Respiratory dysfunction during sepsis is common. However, although lung function can often be adequately supported, death frequently results from cardiovascular collapse. Despite intense investigation, the mechanism underlying the myocardial dysfunction of sepsis remains unclear. Macrophage migration inhibitory factor (MIF), an important cytokine released in sepsis and the acute respiratory distress syndrome, is a known cardiac depressant. We hypothesized that MIF released from the lung results in myocardial dysfunction during sepsis. In murine models of polymicrobial sepsis, we demonstrate a significant increase in the lungs of total and lavagable MIF between 20 and 30 h post induction of sepsis. At 30 h post sepsis, the lungs released MIF into the pulmonary circulation, increasing the plasma concentration by up to 51% in a single pass. Exogenous MIF, instilled into the lungs, increased alveolar keratinocyte-derived chemokine (KC), Macrophage inflammatory protein-2 (MIP2), and tumor necrosis factor alpha (TNFalpha) at 3 h, and plasma KC and MIP2 at 6 h postinstillation. This was associated with an increase in p38 mitogen-activated protein kinase and c-Jun N-terminal kinase phosphorylation. Because changes in mitogen-activated protein kinase activation can lead to myocardial depression, these data suggest that MIF released from the lungs may be responsible, at least in part, for the cardiac dysfunction seen in the late stages of sepsis.
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Affiliation(s)
- Xinchun Lin
- Department of Surgery, Institute for Medical Research at North Shore-LIJ Health System, Manhasset, New York, NY 11030, USA
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