1
|
Ramanathan R, Patwa SA, Ali AH, Ibdah JA. Thyroid Hormone and Mitochondrial Dysfunction: Therapeutic Implications for Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD). Cells 2023; 12:2806. [PMID: 38132126 PMCID: PMC10741470 DOI: 10.3390/cells12242806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/30/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023] Open
Abstract
Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly termed nonalcoholic fatty liver disease (NAFLD), is a widespread global health concern that affects around 25% of the global population. Its influence is expanding, and it is anticipated to overtake alcohol as the leading cause of liver failure and liver-related death worldwide. Unfortunately, there are no approved therapies for MASLD; as such, national and international regulatory health agencies undertook strategies and action plans designed to expedite the development of drugs for treatment of MASLD. A sedentary lifestyle and an unhealthy diet intake are important risk factors. Western countries have a greater estimated prevalence of MASLD partly due to lifestyle habits. Mitochondrial dysfunction is strongly linked to the development of MASLD. Further, it has been speculated that mitophagy, a type of mitochondrial quality control, may be impaired in MASLD. Thyroid hormone (TH) coordinates signals from the nuclear and mitochondrial genomes to control mitochondrial biogenesis and function in hepatocytes. Mitochondria are known TH targets, and preclinical and clinical studies suggest that TH, thyroid receptor β (TR-β) analogs, and synthetic analogs specific to the liver could be of therapeutic benefit in treating MASLD. In this review, we highlight how mitochondrial dysfunction contributes to development of MASLD, and how understanding the role of TH in improving mitochondrial function paved the way for innovative drug development programs of TH-based therapies targeting MASLD.
Collapse
Affiliation(s)
- Raghu Ramanathan
- Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA; (R.R.); (A.H.A.)
- Harry S. Truman Memorial Veterans Medical Center, University of Missouri, Columbia, MO 65212, USA
| | - Sohum A. Patwa
- Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA; (R.R.); (A.H.A.)
| | - Ahmad Hassan Ali
- Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA; (R.R.); (A.H.A.)
- Harry S. Truman Memorial Veterans Medical Center, University of Missouri, Columbia, MO 65212, USA
| | - Jamal A. Ibdah
- Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA; (R.R.); (A.H.A.)
- Harry S. Truman Memorial Veterans Medical Center, University of Missouri, Columbia, MO 65212, USA
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO 65212, USA
| |
Collapse
|
2
|
Vardar Acar N, Özgül RK. A big picture of the mitochondria-mediated signals: From mitochondria to organism. Biochem Biophys Res Commun 2023; 678:45-61. [PMID: 37619311 DOI: 10.1016/j.bbrc.2023.08.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/02/2023] [Accepted: 08/16/2023] [Indexed: 08/26/2023]
Abstract
Mitochondria, well-known for years as the powerhouse and biosynthetic center of the cell, are dynamic signaling organelles beyond their energy production and biosynthesis functions. The metabolic functions of mitochondria, playing an important role in various biological events both in physiological and stress conditions, transform them into important cellular stress sensors. Mitochondria constantly communicate with the rest of the cell and even from other cells to the organism, transmitting stress signals including oxidative and reductive stress or adaptive signals such as mitohormesis. Mitochondrial signal transduction has a vital function in regulating integrity of human genome, organelles, cells, and ultimately organism.
Collapse
Affiliation(s)
- Neşe Vardar Acar
- Department of Pediatric Metabolism, Institute of Child Health, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - R Köksal Özgül
- Department of Pediatric Metabolism, Institute of Child Health, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
3
|
Sabatino L. Nrf2-Mediated Antioxidant Defense and Thyroid Hormone Signaling: A Focus on Cardioprotective Effects. Antioxidants (Basel) 2023; 12:1177. [PMID: 37371907 DOI: 10.3390/antiox12061177] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/24/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023] Open
Abstract
Thyroid hormones (TH) perform a plethora of actions in numerous tissues and induce an overall increase in metabolism, with an augmentation in energy demand and oxygen expenditure. Oxidants are required for normal thyroid-cell proliferation, as well as for the synthesis of the main hormones secreted by the thyroid gland, triiodothyronine (T3) and thyroxine (T4). However, an uncontrolled excess of oxidants can cause oxidative stress, a major trigger in the pathogenesis of a broad spectrum of diseases, including inflammation and cancer. In particular, oxidative stress is implicated in both hypo- and hyper-thyroid diseases. Furthermore, it is important for the TH system to rely on efficient antioxidant defense, to maintain balance, despite sustained tissue exposure to oxidants. One of the main endogenous antioxidant responses is the pathway centered on the nuclear factor erythroid 2-related factor (Nrf2). The aim of the present review is to explore the multiple links between Nrf2-related pathways and various TH-associated conditions. The main aspect of TH signaling is described and the role of Nrf2 in oxidant-antioxidant homeostasis in the TH system is evaluated. Next, the antioxidant function of Nrf2 associated with oxidative stress induced by TH pathological excess is discussed and, subsequently, particular attention is given to the cardioprotective role of TH, which also acts through the mediation of Nrf2. In conclusion, the interaction between Nrf2 and most common natural antioxidant agents in altered states of TH is briefly evaluated.
Collapse
Affiliation(s)
- Laura Sabatino
- Institute of Clinical Physiology, National Research Council, Via Moruzzi 1, 56124 Pisa, Italy
| |
Collapse
|
4
|
Aksoy O, Hantusch B, Kenner L. Emerging role of T3-binding protein μ-crystallin (CRYM) in health and disease. Trends Endocrinol Metab 2022; 33:804-816. [PMID: 36344381 DOI: 10.1016/j.tem.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Thyroid hormones are essential metabolic and developmental regulators that exert a huge variety of effects in different organs. Triiodothyronine (T3) and thyroxine (T4) are synthesized in the thyroid gland and constitute unique iodine-containing hormones that are constantly regulated by a homeostatic feedback mechanism. T3/T4 activity in cells is mainly determined by specific transporters, cytosolic binding proteins, deiodinases (DIOs), and nuclear receptors. Modulation of intracellular T3/T4 level contributes to the maintenance of this regulatory feedback. μ-Crystallin (CRYM) is an important intracellular high-affinity T3-binding protein that buffers the amount of T3 freely available in the cytosol, thereby controlling its action. In this review, we focus on the molecular and pathological properties of CRYM in thyroid hormone signaling, with emphasis on its critical role in malignancies.
Collapse
Affiliation(s)
- Osman Aksoy
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Brigitte Hantusch
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Lukas Kenner
- Department of Pathology, Medical University of Vienna, Vienna, Austria; Center for Biomarker Research in Medicine (CBmed), Graz, Austria; Unit for Laboratory Animal Pathology, University of Veterinary Medicine Vienna, Vienna, Austria; Christian Doppler Laboratory for Applied Metabolomics (CDL-AM), Medical University of Vienna, Vienna, Austria.
| |
Collapse
|
5
|
Role of thyroid hormones-induced oxidative stress on cardiovascular physiology. Biochim Biophys Acta Gen Subj 2022; 1866:130239. [PMID: 36064072 DOI: 10.1016/j.bbagen.2022.130239] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/21/2021] [Accepted: 08/09/2022] [Indexed: 11/21/2022]
Abstract
Thyroid hormones (THs) play an essential role in the maintenance of cardiovascular homeostasis and are involved in the modulation of cardiac contractility, heart rate, diastolic function, systemic vascular resistance, and vasodilation. THs have actions on cardiovascular physiology through the activation or repression of target genes or the activation of intracellular signals through non-genomic mechanisms. Hyperthyroidism alters certain intracellular pathways involved in the preservation of the structure and functionality of the heart, causing relevant cardiovascular disorders. Reactive oxygen species (ROS) play an important role in the cardiovascular system, but the exacerbated increase in ROS caused by chronic hyperthyroidism together with regulation on the antioxidant system have been associated with the development of cardiovascular dysfunction. In this review, we analyze the role of THs-induced oxidative stress in the cellular and molecular changes that lead to cardiac dysfunction, as well as the effectiveness of antioxidant treatments in attenuating cardiac abnormalities developed during hyperthyroidism.
Collapse
|
6
|
Affortit C, Blanc F, Nasr J, Ceccato JC, Markossian S, Guyot R, Puel JL, Flamant F, Wang J. A disease-associated mutation in thyroid hormone receptor α1 causes hearing loss and sensory hair cell patterning defects in mice. Sci Signal 2022; 15:eabj4583. [PMID: 35700264 DOI: 10.1126/scisignal.abj4583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Resistance to thyroid hormone due to mutations in THRA, which encodes the thyroid hormone receptor α (TRα1), shows variable clinical presentation. Mutations affecting TRβ1 and TRβ2 cause deafness in mice and have been associated with deafness in humans. To test whether TRα1 also affects hearing function, we used mice heterozygous for a frameshift mutation in Thra that is similar to human THRA mutations (ThraS1/+ mice) and reduces tissue sensitivity to thyroid hormone. Compared to wild-type littermates, ThraS1/+ mice showed moderate high-frequency sensorineural hearing loss as juveniles and increased age-related hearing loss. Ultrastructural examination revealed aberrant orientation of ~20% of sensory outer hair cells (OHCs), as well as increased numbers of mitochondria with fragmented morphology and autophagic vacuoles in both OHCs and auditory nerve fibers. Molecular dissection of the OHC lateral wall components revealed that the potassium ion channel Kcnq4 was aberrantly targeted to the cytoplasm of mutant OHCs. In addition, mutant cochleae showed increased oxidative stress, autophagy, and mitophagy associated with greater age-related cochlear cell damage, demonstrating that TRα1 is required for proper development of OHCs and for maintenance of OHC function. These findings suggest that patients with THRA mutations may present underdiagnosed, mild hearing loss and may be more susceptible to age-related hearing loss.
Collapse
Affiliation(s)
- Corentin Affortit
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Fabian Blanc
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France.,Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, Montpellier, France
| | - Jamal Nasr
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Jean-Charles Ceccato
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Suzy Markossian
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS, Lyon, France
| | - Romain Guyot
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS, Lyon, France
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Frédéric Flamant
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS, Lyon, France
| | - Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France.,Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, Montpellier, France
| |
Collapse
|
7
|
Paisdzior S, Schuelke M, Krude H. What is the Role of Thyroid Hormone Receptor Alpha 2 (TRα2) in Human Physiology? Exp Clin Endocrinol Diabetes 2022; 130:296-302. [PMID: 35255520 DOI: 10.1055/a-1716-7980] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Thyroid hormone receptors are nuclear receptors that function as transcription factors and are regulated by thyroid hormones. To date, a number of variants and isoforms are known. This review focuses on the thyroid hormone receptor α (TRα), in particular TRα2, an isoform that arises from alternative splicing of the THRA mRNA transcript. Unlike the TRα1 isoform, which can bind T3, the TRα2 isoform lacks a ligand-binding domain but still binds to DNA thereby antagonizing the transcriptional activity of TRα1. Although a regulatory role has been proposed, the physiological function of this TRα2 antagonism is still unclear due to limited in vitro and mouse model data. Recently, the first patients with resistance to thyroid hormone due to mutations in THRA, the TRα encoding gene, affecting the antagonistic function of TRα2 were described, suggesting a significant role of this particular isoform in human physiology.
Collapse
Affiliation(s)
- Sarah Paisdzior
- Institute of Experimental Pediatric Endocrinology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Markus Schuelke
- NeuroCure Cluster of Excellence; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Neuropediatrics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Heiko Krude
- Institute of Experimental Pediatric Endocrinology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| |
Collapse
|
8
|
Cioffi F, Giacco A, Goglia F, Silvestri E. Bioenergetic Aspects of Mitochondrial Actions of Thyroid Hormones. Cells 2022; 11:cells11060997. [PMID: 35326451 PMCID: PMC8947633 DOI: 10.3390/cells11060997] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/04/2022] [Accepted: 03/13/2022] [Indexed: 02/07/2023] Open
Abstract
Much is known, but there is also much more to discover, about the actions that thyroid hormones (TH) exert on metabolism. Indeed, despite the fact that thyroid hormones are recognized as one of the most important regulators of metabolic rate, much remains to be clarified on which mechanisms control/regulate these actions. Given their actions on energy metabolism and that mitochondria are the main cellular site where metabolic transformations take place, these organelles have been the subject of extensive investigations. In relatively recent times, new knowledge concerning both thyroid hormones (such as the mechanisms of action, the existence of metabolically active TH derivatives) and the mechanisms of energy transduction such as (among others) dynamics, respiratory chain organization in supercomplexes and cristes organization, have opened new pathways of investigation in the field of the control of energy metabolism and of the mechanisms of action of TH at cellular level. In this review, we highlight the knowledge and approaches about the complex relationship between TH, including some of their derivatives, and the mitochondrial respiratory chain.
Collapse
|
9
|
Schiera G, Di Liegro CM, Di Liegro I. Involvement of Thyroid Hormones in Brain Development and Cancer. Cancers (Basel) 2021; 13:2693. [PMID: 34070729 PMCID: PMC8197921 DOI: 10.3390/cancers13112693] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 12/21/2022] Open
Abstract
The development and maturation of the mammalian brain are regulated by thyroid hormones (THs). Both hypothyroidism and hyperthyroidism cause serious anomalies in the organization and function of the nervous system. Most importantly, brain development is sensitive to TH supply well before the onset of the fetal thyroid function, and thus depends on the trans-placental transfer of maternal THs during pregnancy. Although the mechanism of action of THs mainly involves direct regulation of gene expression (genomic effects), mediated by nuclear receptors (THRs), it is now clear that THs can elicit cell responses also by binding to plasma membrane sites (non-genomic effects). Genomic and non-genomic effects of THs cooperate in modeling chromatin organization and function, thus controlling proliferation, maturation, and metabolism of the nervous system. However, the complex interplay of THs with their targets has also been suggested to impact cancer proliferation as well as metastatic processes. Herein, after discussing the general mechanisms of action of THs and their physiological effects on the nervous system, we will summarize a collection of data showing that thyroid hormone levels might influence cancer proliferation and invasion.
Collapse
Affiliation(s)
- Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy; (G.S.); (C.M.D.L.)
| | - Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy; (G.S.); (C.M.D.L.)
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| |
Collapse
|
10
|
Ruuskanen S, Hsu BY, Nord A. Endocrinology of thermoregulation in birds in a changing climate. Mol Cell Endocrinol 2021; 519:111088. [PMID: 33227349 DOI: 10.1016/j.mce.2020.111088] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023]
Abstract
The ability to maintain a (relatively) stable body temperature in a wide range of thermal environments by use of endogenous heat production is a unique feature of endotherms such as birds. Endothermy is acquired and regulated via various endocrine and molecular pathways, and ultimately allows wide aerial, aquatic, and terrestrial distribution in variable environments. However, due to our changing climate, birds are faced with potential new challenges for thermoregulation, such as more frequent extreme weather events, lower predictability of climate, and increasing mean temperature. We provide an overview on thermoregulation in birds and its endocrine and molecular mechanisms, pinpointing gaps in current knowledge and recent developments, focusing especially on non-model species to understand the generality of, and variation in, mechanisms. We highlight plasticity of thermoregulation and underlying endocrine regulation, because thorough understanding of plasticity is key to predicting responses to changing environmental conditions. To this end, we discuss how changing climate is likely to affect avian thermoregulation and associated endocrine traits, and how the interplay between these physiological processes may play a role in facilitating or constraining adaptation to a changing climate. We conclude that while the general patterns of endocrine regulation of thermogenesis are quite well understood, at least in poultry, the molecular and endocrine mechanisms that regulate, e.g. mitochondrial function and plasticity of thermoregulation over different time scales (from transgenerational to daily variation), need to be unveiled. Plasticity may ameliorate climate change effects on thermoregulation to some extent, but the increased frequency of extreme weather events, and associated changes in resource availability, may be beyond the scope and/or speed for plastic responses. This could lead to selection for more tolerant phenotypes, if the underlying physiological traits harbour genetic and individual variation for selection to act on - a key question for future research.
Collapse
Affiliation(s)
| | - Bin-Yan Hsu
- Department of Biology, University of Turku, Finland
| | - Andreas Nord
- Lund University, Department of Biology, Section for Evolutionary Ecology, Ecology Building, Sölvegatan 37, SE-22362, Lund, Sweden
| |
Collapse
|
11
|
Gomaa RS, Mahmoud NM, Mohammed NA. Octreotide (somatostatin analog) attenuates cardiac ischemia/reperfusion injury via activating nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway in rat model of hyperthyroidism. FUTURE JOURNAL OF PHARMACEUTICAL SCIENCES 2020. [DOI: 10.1186/s43094-020-00127-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Abstract
Background
Hyperthyroidism is known to increase the risk of ischemic heart diseases. Octreotide has been reported to attenuate ischemia/reperfusion (I/R) injury. Whether it is useful when ischemic heart disease is accompanied with co-morbidities like hyperthyroidism needs more clarifying. So, this study aimed to explore the effect of octreotide on cardiac I/R injury in hyperthyroid rats and to clarify if Nrf2 activation is involved in this effect. Forty adult female Wistar rats were subdivided into control (euthyroid) (n = 10) and hyperthyroid (n = 30) groups. Rats in hyperthyroid group received l-thyroxine (12 mg/L) in drinking water for 35 days, then were randomly divided into three equal subgroups (n = 10): hyperthyroid control positive group, hyperthyroid octreotide treated group, and hyperthyroid octreotide + Nrf2 inhibitor (brusatol) treated group. Isolated hearts were submitted to I/R and evaluated for cardiac hemodynamics and infarct size. Serum T3 and T4, coronary efflux lactate dehydrogenase (LDH) and creatine kinase-myoglobin binding (CK-MB) and cardiac tissue malondialdehyde (MDA) were estimated. Nrf2- regulated gene expressions of HO-1, SOD, GPx, and catalase were assessed.
Results
Octreotide administration to hyperthyroid rats improved baseline and post-ischemic recovery of cardiac hemodynamics, decreased the high coronary efflux LDH and CK-MB and tissue MDA, reduced infarction size, and upregulated the decreased antioxidative enzymes HO-1, SOD, GPx, and catalase mRNA expressions in the hyperthyroid I/R rat hearts. The Nrf2 inhibitor brusatol reversed the cardioprotective effect of octreotide in hyperthyroid I/R rat hearts.
Conclusion
Octreotide can reduce oxidative stress to effectively alleviate I/R injury in the hyperthyroid rat hearts through upregulation of Nrf2-dependent antioxidative signaling pathways.
Collapse
|
12
|
Giammanco M, Di Liegro CM, Schiera G, Di Liegro I. Genomic and Non-Genomic Mechanisms of Action of Thyroid Hormones and Their Catabolite 3,5-Diiodo-L-Thyronine in Mammals. Int J Mol Sci 2020; 21:ijms21114140. [PMID: 32532017 PMCID: PMC7312989 DOI: 10.3390/ijms21114140] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/05/2020] [Accepted: 06/08/2020] [Indexed: 02/06/2023] Open
Abstract
Since the realization that the cellular homologs of a gene found in the retrovirus that contributes to erythroblastosis in birds (v-erbA), i.e. the proto-oncogene c-erbA encodes the nuclear receptors for thyroid hormones (THs), most of the interest for THs focalized on their ability to control gene transcription. It was found, indeed, that, by regulating gene expression in many tissues, these hormones could mediate critical events both in development and in adult organisms. Among their effects, much attention was given to their ability to increase energy expenditure, and they were early proposed as anti-obesity drugs. However, their clinical use has been strongly challenged by the concomitant onset of toxic effects, especially on the heart. Notably, it has been clearly demonstrated that, besides their direct action on transcription (genomic effects), THs also have non-genomic effects, mediated by cell membrane and/or mitochondrial binding sites, and sometimes triggered by their endogenous catabolites. Among these latter molecules, 3,5-diiodo-L-thyronine (3,5-T2) has been attracting increasing interest because some of its metabolic effects are similar to those induced by T3, but it seems to be safer. The main target of 3,5-T2 appears to be the mitochondria, and it has been hypothesized that, by acting mainly on mitochondrial function and oxidative stress, 3,5-T2 might prevent and revert tissue damages and hepatic steatosis induced by a hyper-lipid diet, while concomitantly reducing the circulating levels of low density lipoproteins (LDL) and triglycerides. Besides a summary concerning general metabolism of THs, as well as their genomic and non-genomic effects, herein we will discuss resistance to THs and the possible mechanisms of action of 3,5-T2, also in relation to its possible clinical use as a drug.
Collapse
Affiliation(s)
- Marco Giammanco
- Department of Surgical, Oncological and Oral Sciences (Discipline Chirurgiche, Oncologiche e Stomatologiche), University of Palermo, 90127 Palermo, Italy;
| | - Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF)), University of Palermo, 90128 Palermo, Italy; (C.M.D.L.); (G.S.)
| | - Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF)), University of Palermo, 90128 Palermo, Italy; (C.M.D.L.); (G.S.)
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica avanzata (Bi.N.D.)), University of Palermo, 90127 Palermo, Italy
- Correspondence: ; Tel.: +39-091-2389-7415 or +39-091-2389-7446
| |
Collapse
|
13
|
Noli L, Khorsandi SE, Pyle A, Giritharan G, Fogarty N, Capalbo A, Devito L, Jovanovic VM, Khurana P, Rosa H, Kolundzic N, Cvoro A, Niakan KK, Malik A, Foulk R, Heaton N, Ardawi MS, Chinnery PF, Ogilvie C, Khalaf Y, Ilic D. Effects of thyroid hormone on mitochondria and metabolism of human preimplantation embryos. Stem Cells 2020; 38:369-381. [PMID: 31778245 PMCID: PMC7064942 DOI: 10.1002/stem.3129] [Citation(s) in RCA: 16] [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: 09/28/2019] [Accepted: 11/13/2019] [Indexed: 12/19/2022]
Abstract
Thyroid hormones are regarded as the major controllers of metabolic rate and oxygen consumption in mammals. Although it has been demonstrated that thyroid hormone supplementation improves bovine embryo development in vitro, the cellular mechanisms underlying these effects are so far unknown. In this study, we investigated the role of thyroid hormone in development of human preimplantation embryos. Embryos were cultured in the presence or absence of 10-7 M triiodothyronine (T3) till blastocyst stage. Inner cell mass (ICM) and trophectoderm (TE) were separated mechanically and subjected to RNAseq or quantification of mitochondrial DNA copy number. Analyses were performed using DESeq (v1.16.0 on R v3.1.3), MeV4.9 and MitoMiner 4.0v2018 JUN platforms. We found that the exposure of human preimplantation embryos to T3 had a profound impact on nuclear gene transcription only in the cells of ICM (1178 regulated genes-10.5% of 11 196 expressed genes) and almost no effect on cells of TE (38 regulated genes-0.3% of expressed genes). The analyses suggest that T3 induces in ICM a shift in ribosome and oxidative phosphorylation activity, as the upregulated genes are contributing to the composition and organization of the respiratory chain and associated cofactors involved in mitoribosome assembly and stability. Furthermore, a number of genes affecting the citric acid cycle energy production have reduced expression. Our findings might explain why thyroid disorders in women have been associated with reduced fertility and adverse pregnancy outcome. Our data also raise a possibility that supplementation of culture media with T3 may improve outcomes for women undergoing in vitro fertilization.
Collapse
Affiliation(s)
- Laila Noli
- Division of Women's and Children's Health, Faculty of Life Sciences and MedicineKing's College London and Assisted Conception Unit, Guy's HospitalLondonUK
- Department of Pathological SciencesFakeeh College for Medical SciencesJeddahSaudi Arabia
| | | | - Angela Pyle
- Wellcome Trust Centre for Mitochondrial ResearchInstitute of Genetic Medicine, Newcastle UniversityNewcastle upon TyneUK
| | | | - Norah Fogarty
- Human Embryo and Stem Cell LaboratoryThe Francis Crick InstituteLondonUK
| | - Antonio Capalbo
- Igenomix Italyvia Fermi 1, MarosticaItaly
- DAHFMO, Unit of Histology and Medical Embryology, Sapienza, University of RomeRomeItaly
| | - Liani Devito
- Division of Women's and Children's Health, Faculty of Life Sciences and MedicineKing's College London and Assisted Conception Unit, Guy's HospitalLondonUK
| | - Vladimir M. Jovanovic
- Bioinformatics Solution Center and Human Biology Group; Institute for Zoology; Department of Biology, Chemistry and PharmacyFreie Universität BerlinBerlinGermany
| | - Preeti Khurana
- Division of Women's and Children's Health, Faculty of Life Sciences and MedicineKing's College London and Assisted Conception Unit, Guy's HospitalLondonUK
| | - Hannah Rosa
- MitoDNA Service LabKing's College LondonLondonUK
| | - Nikola Kolundzic
- Division of Women's and Children's Health, Faculty of Life Sciences and MedicineKing's College London and Assisted Conception Unit, Guy's HospitalLondonUK
| | - Aleksandra Cvoro
- Center for BioenergeticsHouston Methodist Research InstituteHoustonTexas
| | - Kathy K. Niakan
- Human Embryo and Stem Cell LaboratoryThe Francis Crick InstituteLondonUK
| | - Afshan Malik
- MitoDNA Service LabKing's College LondonLondonUK
| | | | - Nigel Heaton
- Institute of Liver Studies, King's College HospitalLondonUK
| | - Mohammad Saleh Ardawi
- Department of Pathological SciencesFakeeh College for Medical SciencesJeddahSaudi Arabia
| | - Patrick F. Chinnery
- MRC‐Mitochondrial Biology Unit and Department of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Caroline Ogilvie
- Department of Medical and Molecular GeneticsKing's College LondonLondonUK
| | - Yacoub Khalaf
- Division of Women's and Children's Health, Faculty of Life Sciences and MedicineKing's College London and Assisted Conception Unit, Guy's HospitalLondonUK
| | - Dusko Ilic
- Division of Women's and Children's Health, Faculty of Life Sciences and MedicineKing's College London and Assisted Conception Unit, Guy's HospitalLondonUK
| |
Collapse
|
14
|
Köhrle J, Lehmphul I, Pietzner M, Renko K, Rijntjes E, Richards K, Anselmo J, Danielsen M, Jonklaas J. 3,5-T2-A Janus-Faced Thyroid Hormone Metabolite Exerts Both Canonical T3-Mimetic Endocrine and Intracrine Hepatic Action. Front Endocrinol (Lausanne) 2020; 10:787. [PMID: 31969860 PMCID: PMC6960127 DOI: 10.3389/fendo.2019.00787] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022] Open
Abstract
Over the last decades, thyroid hormone metabolites (THMs) received marked attention as it has been demonstrated that they are bioactive compounds. Their concentrations were determined by immunoassay or mass-spectrometry methods. Among those metabolites, 3,5-diiodothyronine (3,5-T2), occurs at low nanomolar concentrations in human serum, but might reach tissue concentrations similar to those of T4 and T3, at least based on data from rodent models. However, the immunoassay-based measurements in human sera revealed remarkable variations depending on antibodies used in the assays and thus need to be interpreted with caution. In clinical experimental approaches in euthyroid volunteers and hypothyroid patients using the immunoassay as the analytical tool no evidence of formation of 3,5-T2 from its putative precursors T4 or T3 was found, nor was any support found for the assumption that 3,5-T2 might represent a direct precursor for serum 3-T1-AM generated by combined deiodination and decarboxylation from 3,5-T2, as previously documented for mouse intestinal mucosa. We hypothesized that lowered endogenous production of 3,5-T2 in patients requiring T4 replacement therapy after thyroidectomy or for treatment of autoimmune thyroid disease, compared to production of 3,5-T2 in individuals with intact thyroid glands might contribute to the discontent seen in a subset of patients with this therapeutic regimen. So far, our observations do not support this assumption. However, the unexpected association between high serum 3,5-T2 and elevated urinary concentrations of metabolites related to coffee consumption requires further studies for an explanation. Elevated 3,5-T2 serum concentrations were found in several situations including impaired renal function, chronic dialysis, sepsis, non-survival in the ICU as well as post-operative atrial fibrillation (POAF) in studies using a monoclonal antibody-based chemoluminescence immunoassay. Pilot analysis of human sera using LC-linear-ion-trap-mass-spectrometry yielded 3,5-T2 concentrations below the limit of quantification in the majority of cases, thus the divergent results of both methods need to be reconciliated by further studies. Although positive anti-steatotic effects have been observed in rodent models, use of 3,5-T2 as a muscle anabolic, slimming or fitness drug, easily obtained without medical prescription, must be advised against, considering its potency in suppressing the HPT axis and causing adverse cardiac side effects. 3,5-T2 escapes regular detection by commercially available clinical routine assays used for thyroid function tests, which may be seriously disrupted in individuals self-administering 3,5-T2 obtained over-the counter or from other sources.
Collapse
Affiliation(s)
- Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ina Lehmphul
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Maik Pietzner
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
- MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Kostja Renko
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Eddy Rijntjes
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Keith Richards
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - João Anselmo
- Endocrinology Department, Hospital Divino Espirito Santo, Ponta Delgada, Portugal
| | - Mark Danielsen
- Division of Endocrinology, Georgetown University, Washington, DC, United States
| | - Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University, Washington, DC, United States
| |
Collapse
|
15
|
Sinha RA, Bruinstroop E, Singh BK, Yen PM. Nonalcoholic Fatty Liver Disease and Hypercholesterolemia: Roles of Thyroid Hormones, Metabolites, and Agonists. Thyroid 2019; 29:1173-1191. [PMID: 31389309 PMCID: PMC6850905 DOI: 10.1089/thy.2018.0664] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background: Thyroid hormones (THs) exert a strong influence on mammalian lipid metabolism at the systemic and hepatic levels by virtue of their roles in regulating circulating lipoprotein, triglyceride (TAG), and cholesterol levels, as well as hepatic TAG storage and metabolism. These effects are mediated by intricate sensing and feedback systems that function at the physiological, metabolic, molecular, and transcriptional levels in the liver. Dysfunction in the pathways involved in lipid metabolism disrupts hepatic lipid homeostasis and contributes to the pathogenesis of metabolic diseases, such as nonalcoholic fatty liver disease (NAFLD) and hypercholesterolemia. There has been strong interest in understanding and employing THs, TH metabolites, and TH mimetics as lipid-modifying drugs. Summary: THs regulate many processes involved in hepatic TAG and cholesterol metabolism to decrease serum cholesterol and intrahepatic lipid content. TH receptor β analogs designed to have less side effects than the natural hormone are currently being tested in phase II clinical studies for NAFLD and hypercholesterolemia. The TH metabolites, 3,5-diiodo-l-thyronine (T2) and T1AM (3-iodothyronamine), have different beneficial effects on lipid metabolism compared with triiodothyronine (T3), although their clinical application is still under investigation. Also, prodrugs and glucagon/T3 conjugates have been developed that direct TH to the liver. Conclusions: TH-based therapies show clinical promise for the treatment of NAFLD and hypercholesterolemia. Strategies for limiting side effects of TH are being developed and may enable TH metabolites and analogs to have specific effects in the liver for treatments of these conditions. These liver-specific effects and potential suppression of the hypothalamic/pituitary/thyroid axis raise the issue of monitoring liver-specific markers of TH action to assess clinical efficacy and dosing of these compounds.
Collapse
Affiliation(s)
- Rohit A. Sinha
- Department of Endocrinology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Eveline Bruinstroop
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Endocrinology & Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Brijesh K. Singh
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M. Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
| |
Collapse
|
16
|
Oxidative Stress Produced by Hyperthyroidism Status Induces the Antioxidant Enzyme Transcription through the Activation of the Nrf-2 Factor in Lymphoid Tissues of Balb/c Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7471890. [PMID: 31281590 PMCID: PMC6589208 DOI: 10.1155/2019/7471890] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 02/28/2019] [Accepted: 04/09/2019] [Indexed: 12/11/2022]
Abstract
Hyperthyroidism is an endocrine disorder characterized by excessive secretion of thyroid hormones T3 and T4. Thyroid hormones exert pleiotropic actions on numerous tissues and induce an overall increase in metabolism, with an increase in energy demand and oxygen consumption. Therefore, the purpose of this study was to investigate the effects of hyperthyroidism on the production of reactive oxygen species (ROS) in lymph node and spleen cells of euthyroid and hyperthyroid mice, analyzing antioxidant mechanisms involved in the restitution of the cellular redox state. For this, thirty female Balb/c (H-2d) mice were randomly divided into two groups: euthyroid (by treatment with placebo) and hyperthyroid (by treatment with 12 mg/l of T4 in drinking water for 30 days). We found a significant increase in ROS and an increase in the genomic and protein expression of the antioxidant enzymes catalase (CAT) and glutathione peroxidase-1 (GPx-1) in lymph node and spleen cells of hyperthyroid mice. In vitro treatment with H2O2 (250 μM) of the lymphoid cells of euthyroid mice increased the expression levels of CAT and GPx-1. The hyperthyroidism increased the phosphorylation levels of Nrf2 (nuclear factor erythroid 2-related factor) and the kinase activity of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK). Additionally, we found an increase in the expression of the classic isoenzymes of PKCα, β and γ. In conclusion, these results indicated that the increase in ROS found in the hyperthyroid state induces the antioxidant enzyme transcription through the activation of the Nrf-2 factor in lymphoid tissues. This shows the influence of hyperthyroidism on the regulation of the cellular antioxidant system.
Collapse
|
17
|
Köhrle J. The Colorful Diversity of Thyroid Hormone Metabolites. Eur Thyroid J 2019; 8:115-129. [PMID: 31259154 PMCID: PMC6587369 DOI: 10.1159/000497141] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 01/22/2019] [Indexed: 12/17/2022] Open
Abstract
Since the discovery of L-thyroxine, the main secretory product of the thyroid gland, and its major metabolite T3, which exerts the majority of thyroid hormone action via ligand-dependent modulation of the function of T3 receptors in nuclei, mitochondria, and other subcellular compartments, various other T4-derived endogenous metabolites have been identified in blood and tissues of humans, animals, and early protochordates. This review addresses major historical milestones and experimental findings resulting in the discovery of the key enzymes of thyroid hormone metabolism, the three selenoprotein deiodinases, as well as the decarboxylases and amine oxidases involved in formation and degradation of recently identified endogenous thyroid hormone metabolites, i.e. 3-iodothyronamine and 3-thyroacetic acid. The concerted action of deiodinases 2 and 3 in regulation of local T3 availability is discussed. Special attention is given to the role of the thyromimetic "hot" metabolite 3,5-T2 and the "cool" 3-iodothyronamine, especially after administration of pharmacological doses of these endogenous thyroid hormone metabolites in various animal experimental models. In addition, available information on the biological roles of the two major acetic acid derivatives of thyroid hormones, i.e. Tetrac and Triac, as well as sulfated metabolites of thyroid hormones is reviewed. This review addresses the consequences of the existence of this broad spectrum of endogenous thyroid hormone metabolites, the "thyronome," beyond the classical thyroid hormone profile comprising T4, T3, and rT3 for appropriate analytical coverage and clinical diagnostics using mass spectrometry versus immunoassays for determination of total and free concentrations of thyroid hormone metabolites in blood and tissues.
Collapse
Affiliation(s)
- Josef Köhrle
- *Josef Köhrle, Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum (CVK), Charité – Universitätsmedizin Berlin, Augustenburger Platz 1, DE–13353 Berlin (Germany), E-Mail
| |
Collapse
|
18
|
Abstract
Thyroid hormone receptors (TRs) were cloned based on their homology with the retroviral oncogene v-ERBA. In Vertebrates two genes, THRA and THRB, encode respectively many isotypes and isoforms of receptors TRα and TRβ, resulting from alternative splicing and/or internal transcription start sites. We present here a wide overview of this diversity and of their mechanisms of action as transcription regulators, as well as alternative actions through cytoplasmic signaling.
Collapse
|
19
|
Cogliati S, Lorenzi I, Rigoni G, Caicci F, Soriano ME. Regulation of Mitochondrial Electron Transport Chain Assembly. J Mol Biol 2018; 430:4849-4873. [DOI: 10.1016/j.jmb.2018.09.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/20/2018] [Accepted: 09/25/2018] [Indexed: 12/26/2022]
|
20
|
Anyetei-Anum CS, Roggero VR, Allison LA. Thyroid hormone receptor localization in target tissues. J Endocrinol 2018; 237:R19-R34. [PMID: 29440347 PMCID: PMC5843491 DOI: 10.1530/joe-17-0708] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 02/12/2018] [Indexed: 12/28/2022]
Abstract
The thyroid hormone receptors, TRα1, TRβ1 and other subtypes, are members of the nuclear receptor superfamily that mediate the action of thyroid hormone signaling in numerous tissues to regulate important physiological and developmental processes. Their most well-characterized role is as ligand-dependent transcription factors; TRs bind thyroid hormone response elements in the presence or absence of thyroid hormone to facilitate the expression of target genes. Although primarily residing in the nucleus, TRα1 and TRβ1 shuttle rapidly between the nucleus and cytoplasm. We have identified multiple nuclear localization signals and nuclear export signals within TRα1 and TRβ1 that interact with importins and exportins, respectively, to mediate translocation across the nuclear envelope. More recently, enigmatic cytoplasmic functions have been ascribed to other TR subtypes, expanding the diversity of the cellular response to thyroid hormone. By integrating data on localization signal motifs, this review provides an overview of the complex interplay between TR's dynamic transport pathways and thyroid hormone signaling activities. We examine the variation in TR subtype response to thyroid hormone signaling, and what is currently known about regulation of the variety of tissue-specific localization patterns, including targeting to the nucleus, the mitochondria and the inner surface of the plasma membrane.
Collapse
Affiliation(s)
| | - Vincent R Roggero
- Department of BiologyCollege of William and Mary, Williamsburg, Virginia, USA
| | - Lizabeth A Allison
- Department of BiologyCollege of William and Mary, Williamsburg, Virginia, USA
| |
Collapse
|
21
|
Prince LM, Rand MD. Methylmercury exposure causes a persistent inhibition of myogenin expression and C2C12 myoblast differentiation. Toxicology 2018; 393:113-122. [PMID: 29104120 PMCID: PMC5757876 DOI: 10.1016/j.tox.2017.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/03/2017] [Accepted: 11/01/2017] [Indexed: 12/11/2022]
Abstract
Methylmercury (MeHg) is a ubiquitous environmental toxicant, best known for its selective targeting of the developing nervous system. MeHg exposure has been shown to cause motor deficits such as impaired gait and coordination, muscle weakness, and muscle atrophy, which have been associated with disruption of motor neurons. However, recent studies have suggested that muscle may also be a target of MeHg toxicity, both in the context of developmental myogenic events and of low-level chronic exposures affecting muscle wasting in aging. We therefore investigated the effects of MeHg on myotube formation, using the C2C12 mouse myoblast model. We found that MeHg inhibits both differentiation and fusion, in a concentration-dependent manner. Furthermore, MeHg specifically and persistently inhibits myogenin (MyoG), a transcription factor involved in myocyte differentiation, within the first six hours of exposure. MeHg-induced reduction in MyoG expression is contemporaneous with a reduction of a number of factors involved in mitochondrial biogenesis and mtDNA transcription and translation, which may implicate a role for mitochondria in mediating MeHg-induced change in the differentiation program. Unexpectedly, inhibition of myoblast differentiation with MeHg parallels inhibition of Notch receptor signaling. Our research establishes muscle cell differentiation as a target for MeHg toxicity, which may contribute to the underlying etiology of motor deficits with MeHg toxicity.
Collapse
Affiliation(s)
- Lisa M Prince
- University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Department of Environmental Medicine, Rochester, NY, 14642, USA.
| | - Matthew D Rand
- University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Department of Environmental Medicine, Rochester, NY, 14642, USA.
| |
Collapse
|
22
|
T-Time again - The diversity of actions of thyroid hormones (TH), their aminergic (TAM) and acetic acid (TAc) metabolites. Mol Cell Endocrinol 2017; 458:1-5. [PMID: 29169509 DOI: 10.1016/j.mce.2017.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|