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Boutin A, Marcus-Samuels B, Eliseeva E, Neumann S, Gershengorn MC. Opposing Effects of EGF Receptor Signaling on Proliferation and Differentiation Initiated by EGF or TSH/EGF Receptor Transactivation. Endocrinology 2022; 163:6770637. [PMID: 36281035 PMCID: PMC9761572 DOI: 10.1210/endocr/bqac136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Indexed: 11/19/2022]
Abstract
Regulation of thyroid cells by thyrotropin (TSH) and epidermal growth factor (EGF) has been known but different effects of these regulators on proliferation and differentiation have been reported. We studied these responses in primary cultures of human thyroid cells to determine whether TSH receptor (TSHR) signaling may involve EGF receptor (EGFR) transactivation. We confirm that EGF stimulates proliferation and de-differentiation whereas TSH causes differentiation in the absence of other growth factors. We show that TSH/TSHR transactivates EGFR and characterize it as follows: (1) TSH-induced upregulation of thyroid-specific genes is inhibited by 2 inhibitors of EGFR kinase activity, AG1478 and erlotinib; (2) the mechanism of transactivation is independent of an extracellular EGFR ligand by showing that 2 antibodies, cetuximab and panitumumab, that completely inhibited binding of EGFR ligands to EGFR had no effect on transactivation, and by demonstrating that no EGF was detected in media conditioned by thyrocytes incubated with TSH; (3) TSH/TSHR transactivation of EGFR is different than EGFR activation by EGF by showing that EGF led to rapid phosphorylation of EGFR whereas transactivation occurred in the absence of receptor phosphorylation; (4) EGF caused downregulation of EGFR whereas transactivation had no effect on EGFR level; (5) EGF and TSH stimulation converged on the protein kinase B (AKT) pathway, because TSH, like EGF, stimulated phosphorylation of AKT that was inhibited by EGFR inhibitors; and (6) TSH-induced upregulation of thyroid genes was inhibited by the AKT inhibitor MK2206. Thus, TSH/TSHR causes EGFR transactivation that is independent of extracellular EGFR ligand and in part mediates TSH regulation of thyroid hormone biosynthetic genes.
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Affiliation(s)
- Alisa Boutin
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bernice Marcus-Samuels
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elena Eliseeva
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Susanne Neumann
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marvin C Gershengorn
- Correspondence: Marvin C. Gershengorn, MD, 50 South Drive, Rm 4134 Bethesda, MD 20892, USA.
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2
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Jing L, Zhang Q. Intrathyroidal feedforward and feedback network regulating thyroid hormone synthesis and secretion. Front Endocrinol (Lausanne) 2022; 13:992883. [PMID: 36187113 PMCID: PMC9519864 DOI: 10.3389/fendo.2022.992883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Thyroid hormones (THs), including T4 and T3, are produced and released by the thyroid gland under the stimulation of thyroid-stimulating hormone (TSH). The homeostasis of THs is regulated via the coordination of the hypothalamic-pituitary-thyroid axis, plasma binding proteins, and local metabolism in tissues. TH synthesis and secretion in the thyrocytes-containing thyroid follicles are exquisitely regulated by an elaborate molecular network comprising enzymes, transporters, signal transduction machineries, and transcription factors. In this article, we synthesized the relevant literature, organized and dissected the complex intrathyroidal regulatory network into structures amenable to functional interpretation and systems-level modeling. Multiple intertwined feedforward and feedback motifs were identified and described, centering around the transcriptional and posttranslational regulations involved in TH synthesis and secretion, including those underpinning the Wolff-Chaikoff and Plummer effects and thyroglobulin-mediated feedback regulation. A more thorough characterization of the intrathyroidal network from a systems biology perspective, including its topology, constituent network motifs, and nonlinear quantitative properties, can help us to better understand and predict the thyroidal dynamics in response to physiological signals, therapeutic interventions, and environmental disruptions.
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Affiliation(s)
- Li Jing
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing, China
- *Correspondence: Li Jing, ; Qiang Zhang,
| | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
- *Correspondence: Li Jing, ; Qiang Zhang,
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3
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Abstract
Graves' orbitopathy (GO) is a complex and poorly understood disease in which extensive remodeling of orbital tissue is dominated by adipogenesis and hyaluronan production. The resulting proptosis is disfiguring and underpins the majority of GO signs and symptoms. While there is strong evidence for the thyrotropin receptor (TSHR) being a thyroid/orbit shared autoantigen, the insulin-like growth factor 1 receptor (IGF1R) is also likely to play a key role in the disease. The pathogenesis of GO has been investigated extensively in the last decade with further understanding of some aspects of the disease. This is mainly derived by using in vitro and ex vivo analysis of the orbital tissues. Here, we have summarized the features of GO pathogenesis involving target autoantigens and their signaling pathways.
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Affiliation(s)
- Mohd Shazli Draman
- Thyroid Research Group, Cardiff University School of Medicine, Cardiff, United Kingdom
- KPJ Healthcare University College, Nilai, Malaysia
| | - Lei Zhang
- Thyroid Research Group, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Colin Dayan
- Thyroid Research Group, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Marian Ludgate
- Thyroid Research Group, Cardiff University School of Medicine, Cardiff, United Kingdom
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4
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Nassour H, Hoang TA, Martin RD, Dallagnol JCC, Billard É, Létourneau M, Novellino E, Carotenuto A, Allen BG, Tanny JC, Fournier A, Hébert TE, Chatenet D. Lipidated peptides derived from intracellular loops 2 and 3 of the urotensin II receptor act as biased allosteric ligands. J Biol Chem 2021; 297:101057. [PMID: 34389356 PMCID: PMC8424217 DOI: 10.1016/j.jbc.2021.101057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 07/23/2021] [Accepted: 08/05/2021] [Indexed: 01/14/2023] Open
Abstract
Over the last decade, the urotensinergic system, composed of one G protein-coupled receptor and two endogenous ligands, has garnered significant attention as a promising new target for the treatment of various cardiovascular diseases. Indeed, this system is associated with various biomarkers of cardiovascular dysfunctions and is involved in changes in cardiac contractility, fibrosis and hypertrophy contributing, like the angiotensinergic system, to the pathogenesis and progression of heart failure. Significant investment has been made toward the development of clinically relevant UT ligands for therapeutic intervention, but with little or no success to date. This system therefore remains to be therapeutically exploited. Pepducins and other lipidated peptides have been used as both mechanistic probes and potential therapeutics; therefore, pepducins derived from the human urotensin II receptor might represent unique tools to generate signaling bias and study hUT signaling networks. Two hUT-derived pepducins, derived from the second and the third intracellular loop of the receptor (hUT-Pep2 and [Trp1, Leu2]hUT-Pep3, respectively) were synthesized and pharmacologically characterized. Our results demonstrated that hUT-Pep2 and [Trp1, Leu2]hUT-Pep3 acted as biased ago-allosteric modulators, triggered ERK1/2 phosphorylation and to a lesser extent, IP1 production and stimulated cell proliferation yet were devoid of contractile activity. Interestingly, both hUT-derived pepducins were able to modulate human urotensin II (hUII)- and urotensin II-related peptide (URP)-mediated contraction albeit to different extents. These new derivatives represent unique tools to reveal the intricacies of hUT signaling and also a novel avenue for the design of allosteric ligands selectively targeting hUT signaling potentially.
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Affiliation(s)
- Hassan Nassour
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Tuan Anh Hoang
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - Juliana C C Dallagnol
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada; Department of Medicine, Université de Montreal, Montreal Heart Institute, Montreal, Québec, Canada
| | - Étienne Billard
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - Myriam Létourneau
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Ettore Novellino
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Alfonso Carotenuto
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Bruce G Allen
- Department of Medicine, Université de Montreal, Montreal Heart Institute, Montreal, Québec, Canada
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - Alain Fournier
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - David Chatenet
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada.
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5
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Abstract
Thyroid-stimulating hormone (TSH) treatment activates inhibitor of NF-κB/nuclear factor κB (IκB/NFκB) and extracellular signal-regulated kinase (ERK)-P38 in macrophages, but how these pathways are activated, and how they contribute to the proinflammatory effect of TSH on macrophages remain unknown. The TSH receptor (TSHR) is coupled to 4 subfamilies of G proteins (Gs, Gi/o, Gq/11, and G12/13) for its downstream signaling. This study investigated the G protein subtypes responsible for the proinflammatory effect of TSH on macrophages. qPCR showed that Gi2, Gi3, Gas, Gq, G11, G12, G13, and G15 are abundantly expressed by macrophages. The contribution of different G protein pathways to the proinflammatory effect was studied by the corresponding inhibitors or siRNA interference. While TSH-induced IκB phosphorylation was not inhibited by Gs inhibitor NF449, Gi inhibitor pertussis toxin, or Gq or G11 siRNA, it was blocked by phospholipase C inhibitor U73122 or G15 siRNA interference. TSH-induced ERK and P38 phosphorylation was blocked by G13 but not G12 siRNA interference. Interference of either G13 or G15 could block the proinflammatory effect of TSH on macrophages. The present study demonstrate that TSH activates macrophage inflammation by the G13/ERK-P38/Rho GTPase and G15/phospholipase C (PLC)/protein kinases C (PKCs)/IκB pathways.
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Affiliation(s)
- Chongbo Yang
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong First Medical University, Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
| | - Zhao He
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong First Medical University, Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Qunye Zhang
- Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Ministry of Public Health, the State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Ming Lu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong First Medical University, Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong First Medical University, Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
| | - Wenbin Chen
- Scientific Center, Shandong Provincial Hospital affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Ling Gao
- Scientific Center, Shandong Provincial Hospital affiliated to Shandong First Medical University, Jinan, Shandong, China
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Abstract
The insulin-like growth factor (IGF) pathway comprises two activating ligands (IGF-I and IGF-II), two cell-surface receptors (IGF-IR and IGF-IIR), six IGF binding proteins (IGFBP) and nine IGFBP related proteins. IGF-I and the IGF-IR share substantial structural and functional similarities to those of insulin and its receptor. IGF-I plays important regulatory roles in the development, growth, and function of many human tissues. Its pathway intersects with those mediating the actions of many cytokines, growth factors and hormones. Among these, IGFs impact the thyroid and the hormones that it generates. Further, thyroid hormones and thyrotropin (TSH) can influence the biological effects of growth hormone and IGF-I on target tissues. The consequences of this two-way interplay can be far-reaching on many metabolic and immunologic processes. Specifically, IGF-I supports normal function, volume and hormone synthesis of the thyroid gland. Some of these effects are mediated through enhancement of sensitivity to the actions of TSH while others may be independent of pituitary function. IGF-I also participates in pathological conditions of the thyroid, including benign enlargement and tumorigenesis, such as those occurring in acromegaly. With regard to Graves' disease (GD) and the periocular process frequently associated with it, namely thyroid-associated ophthalmopathy (TAO), IGF-IR has been found overexpressed in orbital connective tissues, T and B cells in GD and TAO. Autoantibodies of the IgG class are generated in patients with GD that bind to IGF-IR and initiate the signaling from the TSHR/IGF-IR physical and functional protein complex. Further, inhibition of IGF-IR with monoclonal antibody inhibitors can attenuate signaling from either TSHR or IGF-IR. Based on those findings, the development of teprotumumab, a β-arrestin biased agonist as a therapeutic has resulted in the first medication approved by the US FDA for the treatment of TAO. Teprotumumab is now in wide clinical use in North America.
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7
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Chu YD, Yeh CT. The Molecular Function and Clinical Role of Thyroid Stimulating Hormone Receptor in Cancer Cells. Cells 2020; 9:E1730. [PMID: 32698392 DOI: 10.3390/cells9071730] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 01/18/2023] Open
Abstract
The thyroid stimulating hormone (TSH) and its cognate receptor (TSHR) are of crucial importance for thyrocytes to proliferate and exert their functions. Although TSHR is predominantly expressed in thyrocytes, several studies have revealed that functional TSHR can also be detected in many extra-thyroid tissues, such as primary ovarian and hepatic tissues as well as their corresponding malignancies. Recent advances in cancer biology further raise the possibility of utilizing TSH and/or TSHR as a therapeutic target or as an informative index to predict treatment responses in cancer patients. The TSH/TSHR cascade has been considered a pivotal modulator for carcinogenesis and/or tumor progression in these cancers. TSHR belongs to a sub-group of family A G-protein-coupled receptors (GPCRs), which activate a bundle of well-defined signaling transduction pathways to enhance cell renewal in response to external stimuli. In this review, recent findings regarding the molecular basis of TSH/TSHR functions in either thyroid or extra-thyroid tissues and the potential of directly targeting TSHR as an anticancer strategy are summarized and discussed.
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Boutin A, Krieger CC, Marcus-Samuels B, Klubo-Gwiezdzinska J, Neumann S, Gershengorn MC. TSH Receptor Homodimerization in Regulation of cAMP Production in Human Thyrocytes in vitro. Front Endocrinol (Lausanne) 2020; 11:276. [PMID: 32425890 PMCID: PMC7203478 DOI: 10.3389/fendo.2020.00276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/14/2020] [Indexed: 01/30/2023] Open
Abstract
Thyrotropin hormone (TSH) was reported to exhibit biphasic regulation of cAMP production in human thyroid slices; specifically, upregulation at low TSH doses transitioning to inhibition at high doses. We observed this phenomenon in HEK293 cells overexpressing TSH receptors (TSHRs) but in only 25% of human thyrocytes (hThyros) in vitro. Because TSHR expression in hThyros in vitro was low, we tested the hypothesis that high, in situ levels of TSHRs were needed for biphasic cAMP regulation. We increased expression of TSHRs by infecting hThyros with adenoviruses expressing human TSHR (AdhTSHR), measured TSH-stimulated cAMP production and TSHR homodimerization. TSHR mRNA levels in hThyros in vitro were 100-fold lower than in human thyroid tissue. AdhTSHR infection increased TSHR mRNA expression to levels found in thyroid tissue and flow cytometry showed that cell-surface TSHRs increased more than 15-fold. Most uninfected hThyro preparations exhibited monotonic cAMP production. In contrast, most hThyro preparations infected with AdhTSHR expressing TSHR at in vivo levels exhibited biphasic TSH dose responses. Treatment of AdhTSHR-infected hThyros with pertussis toxin resulted in monotonic dose response curves demonstrating that lower levels of cAMP production at high TSH doses were mediated by Gi/Go proteins. Proximity ligation assays confirmed that AdhTSHR infection markedly increased the number of TSHR homodimers. We conclude that in situ levels of TSHRs as homodimers are needed for hThyros to exhibit biphasic TSH regulation of cAMP production.
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Affiliation(s)
- Alisa Boutin
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health Bethesda, MD, United States
| | - Christine C. Krieger
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health Bethesda, MD, United States
| | - Bernice Marcus-Samuels
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health Bethesda, MD, United States
| | - Joanna Klubo-Gwiezdzinska
- Metabolic Disease Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Susanne Neumann
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health Bethesda, MD, United States
| | - Marvin C. Gershengorn
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health Bethesda, MD, United States
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9
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Shpakov AO. Molecular Mechanisms of the Relationship between Thyroid Dysfunctions and Diabetes Mellitus. J EVOL BIOCHEM PHYS+ 2018. [DOI: 10.1134/s0022093018040014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Ock S, Ahn J, Lee SH, Kim HM, Kang H, Kim YK, Kook H, Park WJ, Kim S, Kimura S, Jung CK, Shong M, Holzenberger M, Abel ED, Lee TJ, Cho BY, Kim HS, Kim J. Thyrocyte-specific deletion of insulin and IGF-1 receptors induces papillary thyroid carcinoma-like lesions through EGFR pathway activation. Int J Cancer 2018; 143:2458-2469. [PMID: 30070361 DOI: 10.1002/ijc.31779] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 07/16/2018] [Accepted: 07/26/2018] [Indexed: 01/25/2023]
Abstract
Insulin and insulin-like growth factor (IGF)-1 signaling in the thyroid are thought to be permissive for the coordinated regulation by thyroid-stimulating hormone (TSH) of thyrocyte proliferation and hormone production. However, the integrated role of insulin receptor (IR) and IGF-1 receptor (IGF-1R) in thyroid development and function has not been explored. Here, we generated thyrocyte-specific IR and IGF-1R double knockout (DTIRKO) mice to precisely evaluate the coordinated functions of these receptors in the thyroid of neonates and adults. Neonatal DTIRKO mice displayed smaller thyroids, paralleling defective folliculogenesis associated with repression of the thyroid-specific transcription factor Foxe1. By contrast, at postnatal day 14, absence of IR and IGF-1R paradoxically induced thyrocyte proliferation, which was mediated by mTOR-dependent signaling pathways. Furthermore, we found elevated production of TSH during the development of follicular hyperplasia at 8 weeks of age. By 50 weeks, all DTIRKO mice developed papillary thyroid carcinoma (PTC)-like lesions that correlated with induction of the ErbB pathway. Taken together, these data define a critical role for IR and IGF-1R in neonatal thyroid folliculogenesis. They also reveal an important reciprocal relationship between IR/IGF-1R and TSH/ErbB signaling in the pathogenesis of thyroid follicular hyperplasia and, possibly, of papillary carcinoma.
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Affiliation(s)
- Sangmi Ock
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Jihyun Ahn
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Seok Hong Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Hyun Min Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Hyun Kang
- Department of Anesthesiology, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Young-Kook Kim
- Department of Biochemistry, Chonnam National University Medical School, Gwangju, Korea
| | - Hyun Kook
- Department of Pharmacology and Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju, Korea
| | - Woo Jin Park
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Shin Kim
- Department of Immunology, Keimyung University School of Medicine, Daegu, Korea
| | - Shioko Kimura
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Chan Kwon Jung
- Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Minho Shong
- Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University, Daejeon, Korea
| | - Martin Holzenberger
- INSERM and Sorbonne University, Saint-Antoine Research Center, Paris, France
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Tae Jin Lee
- Department of Pathology, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Bo Youn Cho
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Ho-Shik Kim
- Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jaetaek Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
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11
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Abstract
The thyroid gland produces thyroid hormones (TH), which are essential regulators for growth, development and metabolism. The thyroid is mainly controlled by the thyroid-stimulating hormone (TSH) that binds to its receptor (TSHR) on thyrocytes and mediates its action via different G protein-mediated signaling pathways. TSH primarily activates the Gs-pathway, and at higher concentrations also the Gq/11-pathway, leading to an increase of intracellular cAMP and Ca2+, respectively. To date, the physiological importance of other G protein-mediated signaling pathways in thyrocytes is unclear. Congenital hypothyroidism (CH) is defined as the lack of TH at birth. In familial cases, high-throughput sequencing methods have facilitated the identification of novel mutations. Nevertheless, the precise etiology of CH yet remains unraveled in a proportion of cases. Genetically modified mouse models can reveal new pathophysiological mechanisms of thyroid diseases. Here, we will present an overview of genetic mouse models for thyroid diseases, which have provided crucial insights into thyroid gland development, function, and growth with a special focus on TSHR and microRNA signaling.
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Affiliation(s)
- C Löf
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, Turku Center for Disease Modeling, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland
| | - K Patyra
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, Turku Center for Disease Modeling, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland
| | - A Kero
- Department of Pediatrics, Turku University Hospital, Kiinamyllynkatu 4-8, 20521, Turku, Finland
| | - J Kero
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, Turku Center for Disease Modeling, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland; Department of Pediatrics, Turku University Hospital, Kiinamyllynkatu 4-8, 20521, Turku, Finland.
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12
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Kleinau G, Worth CL, Kreuchwig A, Biebermann H, Marcinkowski P, Scheerer P, Krause G. Structural-Functional Features of the Thyrotropin Receptor: A Class A G-Protein-Coupled Receptor at Work. Front Endocrinol (Lausanne) 2017; 8:86. [PMID: 28484426 PMCID: PMC5401882 DOI: 10.3389/fendo.2017.00086] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/03/2017] [Indexed: 12/21/2022] Open
Abstract
The thyroid-stimulating hormone receptor (TSHR) is a member of the glycoprotein hormone receptors, a sub-group of class A G-protein-coupled receptors (GPCRs). TSHR and its endogenous ligand thyrotropin (TSH) are of essential importance for growth and function of the thyroid gland and proper function of the TSH/TSHR system is pivotal for production and release of thyroid hormones. This receptor is also important with respect to pathophysiology, such as autoimmune (including ophthalmopathy) or non-autoimmune thyroid dysfunctions and cancer development. Pharmacological interventions directly targeting the TSHR should provide benefits to disease treatment compared to currently available therapies of dysfunctions associated with the TSHR or the thyroid gland. Upon TSHR activation, the molecular events conveying conformational changes from the extra- to the intracellular side of the cell across the membrane comprise reception, conversion, and amplification of the signal. These steps are highly dependent on structural features of this receptor and its intermolecular interaction partners, e.g., TSH, antibodies, small molecules, G-proteins, or arrestin. For better understanding of signal transduction, pathogenic mechanisms such as autoantibody action and mutational modifications or for developing new pharmacological strategies, it is essential to combine available structural data with functional information to generate homology models of the entire receptor. Although so far these insights are fragmental, in the past few decades essential contributions have been made to investigate in-depth the involved determinants, such as by structure determination via X-ray crystallography. This review summarizes available knowledge (as of December 2016) concerning the TSHR protein structure, associated functional aspects, and based on these insights we suggest several receptor complex models. Moreover, distinct TSHR properties will be highlighted in comparison to other class A GPCRs to understand the molecular activation mechanisms of this receptor comprehensively. Finally, limitations of current knowledge and lack of information are discussed highlighting the need for intensified efforts toward TSHR structure elucidation.
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Affiliation(s)
- Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin, Berlin, Germany
- Group Protein X-Ray Crystallography and Signal Transduction, Institute of Medical Physics and Biophysics, Charité-Universitätsmedizin, Berlin, Germany
| | | | - Annika Kreuchwig
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Heike Biebermann
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin, Berlin, Germany
| | | | - Patrick Scheerer
- Group Protein X-Ray Crystallography and Signal Transduction, Institute of Medical Physics and Biophysics, Charité-Universitätsmedizin, Berlin, Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
- *Correspondence: Gerd Krause,
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Müller A, Berkmann JC, Scheerer P, Biebermann H, Kleinau G. Insights into Basal Signaling Regulation, Oligomerization, and Structural Organization of the Human G-Protein Coupled Receptor 83. PLoS One 2016; 11:e0168260. [PMID: 27936173 PMCID: PMC5148169 DOI: 10.1371/journal.pone.0168260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/29/2016] [Indexed: 12/22/2022] Open
Abstract
The murine G-protein coupled receptor 83 (mGPR83) is expressed in the hypothalamus and was previously suggested to be involved in the regulation of metabolism. The neuropeptide PEN has been recently identified as a potent GPR83 ligand. Moreover, GPR83 constitutes functionally relevant hetero-oligomers with other G-protein coupled receptors (GPCR) such as the ghrelin receptor (GHSR) or GPR171. Previous deletion studies also revealed that the long N-terminal extracellular receptor domain (eNDo) of mGPR83 may act as an intra-molecular ligand, which participates in the regulation of basal signaling activity, which is a key feature of GPCR function. Here, we investigated particular amino acids at the eNDo of human GPR83 (hGPR83) by side-directed mutagenesis to identify determinants of the internal ligand. These studies were accompanied by structure homology modeling to combine functional insights with structural information. The capacity for hetero-oligomer formation of hGPR83 with diverse family A GPCRs such as the melanocortin-4 receptor (MC4R) was also investigated, with a specific emphasis on the impact of the eNDo on oligomerization and basal signaling properties. Finally, we demonstrate that hGPR83 exhibits an unusual basal signaling for different effectors, which also supports signaling promiscuity. hGPR83 interacts with a variety of hypothalamic GPCRs such as the MC4R or GHSR. These interactions are not dependent on the ectodomain and most likely occur at interfaces constituted in the transmembrane regions. Moreover, several amino acids at the transition between the eNDo and transmembrane helix 1 were identified, where mutations lead also to biased basal signaling modulation.
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Affiliation(s)
- Anne Müller
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Julia Catherine Berkmann
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Patrick Scheerer
- Institut für Medizinische Physik und Biophysik, Group Protein X-ray Crystallography and Signal Transduction, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Heike Biebermann
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
- * E-mail:
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Mester T, Raychaudhuri N, Gillespie EF, Chen H, Smith TJ, Douglas RS. CD40 Expression in Fibrocytes Is Induced by TSH: Potential Synergistic Immune Activation. PLoS One 2016; 11:e0162994. [PMID: 27631497 PMCID: PMC5025085 DOI: 10.1371/journal.pone.0162994] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/31/2016] [Indexed: 11/23/2022] Open
Abstract
Context Fibrocytes appear to participate in inflammation and tissue remodeling in patients with thyroid-associated ophthalmopathy (TAO). These patients have increased frequencies of circulating TSH receptor (TSHR)- and CD40-positive fibrocytes, suggesting TSHR and CD40 may play roles in proinflammatory cytokine production, which ultimately leads to orbital inflammation and tissue remodeling. Objective To investigate the potential interactions between the TSHR and CD40 signaling pathways and their roles in IL-6 and TNF-α production. Design and Outcome Measures CD40 expression on fibrocytes was assessed using flow cytometry; IL-6 and TNF-α protein release using Luminex technology; increased IL-6 and TNF-α mRNA abundance, using real-time PCR; TSH- and CD40 ligand (CD40L)-stimulated Akt phosphorylation in fibrocytes, by western blot analysis; TSHR-CD40 protein-protein interaction, using co-immunoprecipitation, and CD40-TSHR co-localization, using immunocytochemistry. Results TSH enhances CD40 expression at a pre-translational level in fibrocytes. Production of IL-6 and TNF-α after costimulation with TSH and CD40L was greater than that after TSH or CD40L stimulation alone. TSH and CD40L costimulation also resulted in greater Akt phosphorylation. Akt and nuclear factor (NF)-κB inhibitors significantly reduced cytokine production after TSH and CD40L costimulation. TSHR and CD40L are colocalized on the cell surface and form a complex. Conclusions TSHR and CD40 in fibrocytes appear to be physically and functionally related. TSH stimulates CD40 production on the fibrocyte surface. Cytokine expression upon simultaneous stimulation of TSHR and CD40 is greater than levels achieved with TSH or CD40L alone. Increased expression of CD40 by TSH is a potential mechanism for this process.
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Affiliation(s)
- Tünde Mester
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
| | - Nupur Raychaudhuri
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
| | - Erin F. Gillespie
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
| | - Hong Chen
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
- Department of Ophthalmology of Union Hospital, Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, People's Republic of China
| | - Terry J. Smith
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
- Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
| | - Raymond S. Douglas
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America
- Ann Arbor Veterans Administration Medical Center, Ann Arbor, Michigan, 48105, United States of America
- * E-mail:
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Montesinos MDM, Nicola JP, Nazar M, Peyret V, Lucero AM, Pellizas CG, Masini-Repiso AM. Nitric oxide-repressed Forkhead factor FoxE1 expression is involved in the inhibition of TSH-induced thyroid peroxidase levels. Mol Cell Endocrinol 2016; 420:105-15. [PMID: 26610751 DOI: 10.1016/j.mce.2015.11.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 11/02/2015] [Accepted: 11/13/2015] [Indexed: 01/07/2023]
Abstract
Thyroid peroxidase (TPO) is essential for thyroid hormone synthesis mediating the covalent incorporation of iodine into tyrosine residues of thyroglobulin process known as organification. Thyroid-stimulating hormone (TSH) via cAMP signaling is the main hormonal regulator of TPO gene expression. In thyroid cells, TSH-stimulated nitric oxide (NO) production inhibits TSH-induced thyroid-specific gene expression, suggesting a potential autocrine role of NO in modulating thyroid function. Indeed, NO donors downregulate TSH-induced iodide accumulation and organification in thyroid cells. Here, using FRTL-5 thyroid cells as model, we obtained insights into the molecular mechanism underlying the inhibitory effects of NO on iodide organification. We demonstrated that NO donors inhibited TSH-stimulated TPO expression by inducing a cyclic guanosine monophosphate-dependent protein kinase-mediated transcriptional repression of the TPO gene. Moreover, we characterized the FoxE1 binding site Z as mediator of the NO-inhibited TPO expression. Mechanistically, we demonstrated that NO decreases TSH-induced FoxE1 expression, thus repressing the transcripcional activation of TPO gene. Taken together, we provide novel evidence reinforcing the inhibitory role of NO on thyroid cell function, an observation of potential pathophysiological relevance associated with human thyroid pathologies that come along with changes in the NO production.
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Affiliation(s)
- María del Mar Montesinos
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Juan Pablo Nicola
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Magalí Nazar
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Victoria Peyret
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Ariel Maximiliano Lucero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Claudia Gabriela Pellizas
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Ana María Masini-Repiso
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
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Abstract
Tanycytes play multiple roles in hypothalamic functions, including sensing peripheral nutrients and metabolic hormones, regulating neurosecretion and mediating seasonal cycles of reproduction and metabolic physiology. This last function reflects the expression of TSH receptors in tanycytes, which detect photoperiod-regulated changes in TSH secretion from the neighbouring pars tuberalis. The present overall aim was to determine the signal transduction pathway by which TSH signals in tanycytes. Expression of the TSH receptor in tanycytes of 10-day-old Sprague Dawley rats was observed by in situ hybridisation. Primary ependymal cell cultures prepared from 10-day-old rats were found by immunohistochemistry to express vimentin but not GFAP and by PCR to express mRNA for Dio2, Gpr50, Darpp-32 and Tsh receptors that are characteristic of tanycytes. Treatment of primary tanycyte/ependymal cultures with TSH (100 IU/l) increased cAMP as assessed by ELISA and induced a cAMP-independent increase in the phosphorylation of ERK1/2 as assessed by western blot analysis. Furthermore, TSH (100 IU/l) stimulated a 2.17-fold increase in Dio2 mRNA expression. We conclude that TSH signal transduction in cultured tanycytes signals via Gαs to increase cAMP and via an alternative G protein to increase phosphorylation of ERK1/2.
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Affiliation(s)
- Matei Bolborea
- Rowett Institute of Nutrition and Health University of Aberdeen, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK School of Life Sciences University of Nottingham Medical School, Nottingham NG7 2UH, UK Rowett Institute of Nutrition and Health University of Aberdeen, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK School of Life Sciences University of Nottingham Medical School, Nottingham NG7 2UH, UK
| | - Gisela Helfer
- Rowett Institute of Nutrition and Health University of Aberdeen, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK School of Life Sciences University of Nottingham Medical School, Nottingham NG7 2UH, UK
| | - Francis J P Ebling
- Rowett Institute of Nutrition and Health University of Aberdeen, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK School of Life Sciences University of Nottingham Medical School, Nottingham NG7 2UH, UK
| | - Perry Barrett
- Rowett Institute of Nutrition and Health University of Aberdeen, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK School of Life Sciences University of Nottingham Medical School, Nottingham NG7 2UH, UK
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Abstract
Thyrotropin (TSH) activation of the TSH receptor (TSHR), a 7-transmembrane-spanning receptor (7TMR), may have osteoprotective properties by direct effects on bone. TSHR activation by TSH phosphorylates protein kinases AKT1, p38α, and ERK1/2 in some cells. We found TSH-induced phosphorylation of these kinases in 2 cell lines engineered to express TSHRs, human embryonic kidney HEK-TSHR cells and human osteoblastic U2OS-TSHR cells. In U2OS-TSHR cells, TSH up-regulated pAKT1 (7.1±0.5-fold), p38α (2.9±0.4-fold), and pERK1/2 (3.1±0.2-fold), whereas small molecule TSHR agonist C2 had no or little effect on pAKT1 (1.8±0.08-fold), p38α (1.2±0.09-fold), and pERK1/2 (1.6±0.19-fold). Furthermore, TSH increased expression of osteoblast marker genes ALPL (8.2±4.6-fold), RANKL (21±5.9-fold), and osteopontin (OPN; 17±5.3-fold), whereas C2 had little effect (ALPL, 1.7±0.5-fold; RANKL, 1.3±0.6-fold; and OPN, 2.2±0.7-fold). β-Arrestin-1 and -2 can mediate activatory signals by 7TMRs. TSH stimulated translocation of β-arrestin-1 and -2 to TSHR, whereas C2 failed to translocate either β-arrestin. Down-regulation of β-arrestin-1 by siRNA inhibited TSH-stimulated phosphorylation of ERK1/2, p38α, and AKT1, whereas down-regulation of β-arrestin-2 increased phosphorylation of AKT1 in both cell types and of ERK1/2 in HEK-TSHR cells. Knockdown of β-arrestin-1 inhibited TSH-stimulated up-regulation of mRNAs for OPN by 87 ± 1.7% and RANKL by 73 ± 2.4%, and OPN secretion by 74 ± 10%. We conclude that TSH enhances osteoblast differentiation in U2OS cells that is, in part, caused by activatory signals mediated by β-arrestin-1.
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Affiliation(s)
- Alisa Boutin
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Elena Eliseeva
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Marvin C Gershengorn
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Susanne Neumann
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Abstract
The thyroid-stimulating hormone receptor (TSHR, or thyrotropin receptor) is a family A G protein-coupled receptor. It not only binds thyroid-stimulating hormone (TSH, or thyrotropin) but also interacts with autoantibodies under pathological conditions. The TSHR and TSH are essential for thyroid growth and function and thus for all thyroid hormone-associated physiological superordinated processes, including metabolism and development of the central nervous system. In vitro studies have found that the TSHR permanently stimulates ligand-independent (constitutive) activation of Gs, which ultimately leads to intracellular cAMP accumulation. Furthermore, a vast variety of constitutively activating mutations of TSHR-at more than 50 different amino acid positions-have been reported to enhance basal signaling. These lead in vivo to a "gain-of-function" phenotype of nonautoimmune hyperthyroidism or toxic adenomas. Moreover, many naturally occurring inactivating mutations are known to cause a "loss-of-function" phenotype, resulting in resistance to thyroid hormone or hyperthyrotropinemia. Several of these mutations are also characterized by impaired basal signaling, and these are designated here as "constitutively inactivating mutations" (CIMs). More than 30 amino acid positions with CIMs have been identified so far. Moreover, the permanent TSHR signaling capacity can also be blocked by inverse agonistic antibodies or small drug-like molecules, which both have a potential for clinical usage. In this chapter, information on constitutive activity in the TSHR is described, including up- and downregulation, linked protein conformations, physiological and pathophysiological conditions, and related intracellular signaling.
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Affiliation(s)
- Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
| | - Heike Biebermann
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Abstract
The TSH receptor (TSHR) is a member of the glycoprotein hormone receptors, a subfamily of family A G protein-coupled receptors. The TSHR is of great importance for the growth and function of the thyroid gland. The TSHR and its endogenous ligand TSH are pivotal proteins with respect to a variety of physiological functions and malfunctions. The molecular events of TSHR regulation can be summarized as a process of signal transduction, including signal reception, conversion, and amplification. The steps during signal transduction from the extra- to the intracellular sites of the cell are not yet comprehensively understood. However, essential new insights have been achieved in recent years on the interrelated mechanisms at the extracellular region, the transmembrane domain, and intracellular components. This review contains a critical summary of available knowledge of the molecular mechanisms of signal transduction at the TSHR, for example, the key amino acids involved in hormone binding or in the structural conformational changes that lead to G protein activation or signaling regulation. Aspects of TSHR oligomerization, signaling promiscuity, signaling selectivity, phenotypes of genetic variations, and potential extrathyroidal receptor activity are also considered, because these are relevant to an understanding of the overall function of the TSHR, including physiological, pathophysiological, and pharmacological perspectives. Directions for future research are discussed.
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Affiliation(s)
- Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, Ostring 3, Augustenburger Platz 1, 13353 Berlin, Germany.
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Kwon MS, Park BO, Kim HM, Kim S. Leucine-rich repeat-containing G-protein coupled receptor 5/GPR49 activates G12/13-Rho GTPase pathway. Mol Cells 2013; 36:267-72. [PMID: 23912594 PMCID: PMC3887977 DOI: 10.1007/s10059-013-0173-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 06/27/2013] [Accepted: 06/27/2013] [Indexed: 10/26/2022] Open
Abstract
Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5/GPR49) is highly expressed in adult stem cells of various tissues, such as intestine, hair follicles, and stomach. LGR5 is also overexpressed in some colon and ovarian tumors. Recent reports show that R-spondin (RSPO) family ligands bind to and activate LGR5, enhancing canonical Wnt signaling via the interaction with LRP5/6 and Frizzled. The identity of heterotrimeric G-proteins coupled to LGR5, however, remains unclear. Here, we show that Rho GTPase is a downstream target of LGR5. Overexpression of LGR5 induced SRF-RE luciferase activity, a reporter of Rho signaling. RSPOs, ligands for LGR4, LGR5, and LGR6, however, did not induce SRF-RE reporter activity in the presence of LGR5. Consistently, LGR5-induced activity of the SRF-RE reporter was inhibited by Rho inhibitor C3 transferase and RhoA N19 mutant, and knockdown of Gα12/13 genes blocked the reporter activity induced by LGR5. In addition, focal adhesion kinase, NF-κB and c-fos, targets of Rho GTPase, were shown to be regulated by LGR5. Here, we have demonstrated, for the first time, that LGR5 is coupled to the Rho pathway through G12/13 signaling.
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Affiliation(s)
- Mi So Kwon
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon 363-883, Korea
- Biomolecular Science Major, University of Science and Technology, Daejeon 305-350, Korea
| | - Bi-oh Park
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon 363-883, Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
| | - Sunhong Kim
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon 363-883, Korea
- Biomolecular Science Major, University of Science and Technology, Daejeon 305-350, Korea
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Lorenz S, Aust G, Krohn K. Ca(2+)-binding protein expression in primary human thyrocytes. Biochim Biophys Acta 2013; 1833:2703-13. [PMID: 23886630 DOI: 10.1016/j.bbamcr.2013.07.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 06/04/2013] [Accepted: 07/15/2013] [Indexed: 01/06/2023]
Abstract
We recently identified several Ca(2+)-binding proteins (CaBP) from the S100 and annexin family to be regulated by TSH in FRTL-5 cells. Here, we study the regulation of S100A4, S100A6 and ANXA2 in primary human thyrocytes (PHT) derived from surrounding tissues (ST), cold benign thyroid nodules (CTN) and autonomously functioning thyroid nodules (AFTN). We investigated the expression and regulation of CaBP and the effect of their expression on Ca(2+) and TSHR signaling. We used an approach that accounts for the potential of an individual PHT culture to proliferate or to express thyroid differentiation features by assessing the expression of FOS and TPO. We found a strong correlation between the regulation of CaBP and the proliferation-associated transcription factor gene FOS. PKA and MEK1/2 were regulators of ANXA2 expression, while PI3-K and triiodothyronine were additionally involved in S100 regulation. The modulated expression of CaBP was reflected by changes in ATP-elicited Ca(2+) signaling in PHT. S100A4 increased the ratio of subsequent Ca(2+) responses and showed a Ca(2+) buffering effect, while ANXA2 affected the first Ca(2+) response to ATP. Overexpression of S100A4 led to a reduced activation of NFAT by TSH. Using S100A4 E33Q, D63N, F72Q and Y75K mutants we found that the effects of S100A4 expression on Ca(2+) signaling are mediated by protein interaction. We present evidence that TSH has the ability to fine-tune Ca(2+) signals through the regulation of CaBP expression. This represents a novel putative cross-regulating mechanism in thyrocytes that could affect thyrocyte signaling and physiology.
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Bäck CM, Stohr S, Schäfer EAM, Biebermann H, Boekhoff I, Breit A, Gudermann T, Büch TRH. TSH induces metallothionein 1 in thyrocytes via Gq/11- and PKC-dependent signaling. J Mol Endocrinol 2013; 51:79-90. [PMID: 23613280 DOI: 10.1530/jme-12-0200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Metallothioneins (MTs) are cytoprotective proteins acting as scavengers of toxic metal ions or reactive oxygen species. MTs are upregulated in follicular thyroid carcinoma and are regarded as a marker of thyroid stress in Graves' disease. However, the mechanism of MT regulation in thyrocytes is still elusive. In other cellular systems, cAMP-, calcium-, or protein kinase C (PKC)-dependent signaling cascades have been shown to induce MT expression. Of note, all of these three pathways are activated following the stimulation of the TSH receptor (TSHR). Thus, we hypothesized that TSH represents a key regulator of MT expression in thyrocytes. In fact, TSHR stimulation induced expression of MT isoform 1X (MT1X) in human follicular carcinoma cells. In these cells, Induction of MT1X expression critically relied on intact Gq/11 signaling of the TSHR and was blocked by chelation of intracellular calcium and inhibition of PKC. TSHR-independent stimulation of cAMP formation by treating cells with forskolin also led to an upregulation of MT1X, which was completely dependent on PKA. However, inhibition of PKA did not affect the regulation of MT1X by TSH. As in follicular thyroid carcinoma cells, TSH also induced MT1 protein in primary human thyrocytes, which was PKC dependent as well. In summary, these findings indicate that TSH stimulation induces MT1X expression via Gq/11 and PKC, whereas cAMP-PKA signaling does not play a predominant role. To date, little has been known regarding cAMP-independent effects of TSHR signaling. Our findings extend the knowledge about the PKC-mediated functions of the TSHR.
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Affiliation(s)
- Christer M Bäck
- Medical Department III, University Hospital Aachen, D-52074 Aachen, Germany
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Zaballos MA, Santisteban P. FOXO1 controls thyroid cell proliferation in response to TSH and IGF-I and is involved in thyroid tumorigenesis. Mol Endocrinol 2012; 27:50-62. [PMID: 23160481 DOI: 10.1210/me.2012-1032] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
TSH and insulin/IGF-I synergistically induce the proliferation of thyroid cells mainly through the cAMP and phosphatidylinositol 3-kinase (PI3K) pathways. However, the events involved in this cooperative induction remain unknown, and molecules that are potentially controlled by both TSH and IGF-I are interesting candidates as integrators of both stimuli. The finding that the PI3K pathway is frequently activated in thyroid malignancies has attracted attention to this pathway in the thyroid field. One of the targets of PI3K is Forkhead box O (FoxO)-1, a widely expressed transcription factor involved in a variety of cellular processes such as differentiation, proliferation, and apoptosis. Here we show that FoxO1 is highly expressed in differentiated rat thyroid cells and human thyroid tissue compared with human thyroid tumor-derived cells and surgically removed thyroid tumors, in which its expression is reduced. In differentiated cells, TSH/cAMP treatment decreases FoxO1 mRNA and protein levels through proteasome activation, whereas both TSH and IGF-I control FoxO1 localization by promoting a rapid exclusion from the nucleus in an Akt-dependent manner. FoxO1 can control p27(KIP1) expression in differentiated and tumor cells of the thyroid. Furthermore, FoxO1 reexpression in tumor cells promotes a decrease in their proliferation rate, whereas FoxO1 interference in differentiated cells increases their proliferation. These data point to an important role of FoxO1 in mediating the effects of TSH and IGF-I on thyroid cell proliferation and provide a link between loss of FoxO1 expression and the uncontrolled proliferation of thyroid tumor cells.
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Affiliation(s)
- Miguel A Zaballos
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28029 Madrid, Spain
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Piotrowska U, Adler G, Kozicki I. Diverse β subunits of heterotrimeric G proteins are present in thyroid plasma membranes. Biochem Biophys Res Commun 2011; 414:350-4. [PMID: 21964289 DOI: 10.1016/j.bbrc.2011.09.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 09/14/2011] [Indexed: 10/17/2022]
Abstract
The functioning of heterotrimeric G protein α subunits in the transduction of hormonal signals to appropriate intracellular responses is well recognized. Much less is known about the distribution of isoforms and functions of G protein β subunits. Here, using specific antibodies, we documented that in plasma membranes of the thyroid cell line Nthy-ori 3-1 all Gβ isoforms-Gβ(1), Gβ(2), Gβ(3), Gβ(4) and Gβ(5) are present, while the Gβ(3) occurs in minute amount. In plasma membrane fraction isolated from pooled postoperative thyroids of patients with nodular goiter and Graves' disease, the Gβ(1), Gβ(2), Gβ(4) and Gβ(5) subunits were found, whereas Gβ(3) could not be detected. Competition studies revealed that the Gβ(2) is the principal Gβ subunit in membranes from cultured thyroid cells, originated from normal thyroid, as well as in membranes from patients' thyroids. This suggests that Gβ(2) subunit cooperates with Gα(s) subunit, the most active of the Gα variants, during stimulation of adenylate cyclase which constitutes the main route of physiological thyroid stimulation.
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Affiliation(s)
- Urszula Piotrowska
- Medical Centre of Postgraduate Education, Department of Biochemistry, 01 813 Warsaw, Poland
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Abstract
TSH receptor (TSHR) antibodies (Abs) may be stimulating, blocking, or neutral in their functional influences and are found in patients with autoimmune thyroid disease, especially Graves' disease (GD). Stimulators are known to activate the thyroid epithelial cells via both Gs- and Gq-coupled signaling pathways, whereas blockers inhibit the action of TSH and may act as weak agonists. However, TSHR neutral Abs do not block TSH binding and are unable to induce cAMP via Gsα. The importance of such neutral Abs in GD remains unclear because their functional consequence has been assumed to be zero. We hypothesized that: 1) neutral TSHR Abs are more common to GD than generally recognized; 2) they may induce distinct signaling imprints at the TSHR not seen with TSH itself; and 3) these signaling events may alter cellular function. To evaluate these hypotheses, we first confirmed the presence of neutral TSHR Abs in sera from patients with GD and then, using mouse and hamster neutral TSHR monoclonal Abs (N-mAbs) performed detailed signaling studies, including a proteomic Ab array, with rat thyrocytes (FRTL-5) as targets. This allowed us to examine a battery of signaling cascades and their downstream effectors. Neutral TSHR Abs were indeed frequently present in sera from patients with GD. Sixteen of 27 patients (59%) had detectable neutral TSHR Abs by competition assay with N-mAbs. On examining signaling cascades, we found that N-mAbs induced signal transduction, primarily via the protein kinase A II cascade. In addition to the activation of phosphatidylinositol 3K/Akt, N-mAbs, unlike TSH, had the ability to exclusively activate the mammalian target of rapamycin/p70 S6K, nuclear factor-κB, and MAPK-ERK1/2/p38α signaling cascades and their downstream effectors p90 ribosomal kinase/MAPK-interacting kinase-1/mitogen and stress-activated kinase-1 and N-mAbs activated all forms of protein kinase C isozymes. To define the downstream effector mechanisms produced by these signaling cascades, cytokine production, proliferation, and apoptosis in thyrocytes were investigated. Although N-mAbs produced less cytokines and proliferation compared with TSH, they had the distinction of inducing thyroid cell apoptosis under the experimental conditions used. When dissecting out possible mechanisms of apoptosis, we found that activation of multiple oxidative stress markers was the primary mechanism orchestrating the death signals. Therefore, using oxidative stress-induced apoptosis, N-mAbs may be capable of exacerbating the autoimmune response in GD via apoptotic cells inducing antigen-driven mechanisms. This may help explain the inflammatory nature of this common disorder.
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Affiliation(s)
- Syed A Morshed
- Thyroid Research Unit, Mount Sinai School of Medicine, James J. Peters Veterans Affairs Medical Center, New York, New York 10468, USA.
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Abstract
The biologic role of thyroid-stimulating hormone (TSH; thyrotropin) as an activator (agonist) of the TSH receptor (TSHR) in the hypothalamic-pituitary-thyroid axis is well known and activation of TSHR by recombinant human TSH is used clinically in patients with thyroid cancer. TSHR ligands other than TSH could be used to probe TSHR biology in thyroidal and extrathyroidal tissues, and potentially be employed in patients. A number of different TSHR ligands have been reported, including TSH analogs, antibodies and small-molecule, drug-like compounds. In this review, we will provide an update on all these classes of TSHR agonists and antagonists but place emphasis on small-molecule ligands.
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Affiliation(s)
- Susanne Neumann
- Clinical Endocrinology Branch, NIDDK, NIH, 50 South Drive, Bethesda, MD 20892-28029, USA, Tel.: +1 301 451 6324, Fax: +1 301 480 4214
| | - Bruce M Raaka
- Clinical Endocrinology Branch, NIDDK, NIH, 50 South Drive, Bethesda, MD 20892-28029, USA, Tel.: +1 301 451 6307, Fax: +1 301 480 4214
| | - Marvin C Gershengorn
- Author for correspondence: Clinical Endocrinology Branch, NIDDK, NIH, 50 South Drive, Bethesda, MD 20892-28029, USA, Tel.: +1 301 451 6305, Fax: +1 301 480 4214,
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Abstract
The TSH receptor (TSHR) together with the homologous lutropin/choriogonadotropin receptor and the follitropin receptor are glycoprotein hormone receptors (GPHRs). They constitute a subfamily of the rhodopsin-like G protein-coupled receptors with seven transmembrane helices. GPHRs and their corresponding hormones are pivotal proteins with respect to a variety of physiological functions. The identification and characterization of intra- and intermolecular signaling determinants as well as signaling mechanisms are prerequisites to gaining molecular insights into functions and (pathogenic) dysfunctions of GPHRs. Knowledge about activation mechanisms is fragmentary, and the specific aspects have still not been understood in their entirety. Therefore, here we critically review the data available for these receptors and bring together structural and functional findings with a focus on the important large extracellular portion of the TSHR. One main focus is the particular function of structural determinants in the initial steps of the activation such as: 1) hormone binding at the extracellular site; 2) hormone interaction at a second binding site in the hinge region; 3) signal regulation via sequence motifs in the hinge region; and 4) synergistic signal amplification by cooperative effects of the extracellular loops toward the transmembrane region. Comparison and consolidation of data from the homologous glycoprotein hormone receptors TSHR, follitropin receptor, and lutropin/choriogonadotropin receptor provide an overview of extracellular mechanisms of signal initiation, conduction, and regulation at the TSHR and homologous receptors. Finally, we address the issue of structural implications and suggest a refined scenario for the initial signaling process on GPHRs.
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Affiliation(s)
- Gunnar Kleinau
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
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