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Kolar-Anić L, Čupić Ž, Maćešić S, Ivanović-Šašić A, Dietrich JW. Modelling of the thyroid hormone synthesis as a part of nonlinear reaction mechanism with feedback. Comput Biol Med 2023; 160:106980. [PMID: 37141650 DOI: 10.1016/j.compbiomed.2023.106980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 04/04/2023] [Accepted: 04/23/2023] [Indexed: 05/06/2023]
Abstract
The synthesis of thyroid hormones in the hypothalamic-pituitary-thyroid (HPT) axis was studied. For this purpose, a reaction model for HPT axis with stoichiometric relations between the main reaction species was postulated. Using the law of mass action, this model has been transformed into a set of nonlinear ordinary differential equations. This new model has been examined by stoichiometric network analysis (SNA) with the aim to see if it possesses the ability to reproduce oscillatory ultradian dynamics founded on the internal feedback mechanism. In particular, a feedback regulation of TSH production based on the interplay between TRH, TSH, somatostatin and thyroid hormones was proposed. Besides, the ten times larger amount of produced T4 with respect to T3 in the thyroid gland was successfully simulated. The properties of SNA in combination with experimental results, were used to determine the unknown parameters (19 rate constants of particular reaction steps) necessary for numerical investigations. The steady-state concentrations of 15 reactive species were tuned to be consistent with the experimental data. The predictive potential of the proposed model was illustrated on numerical simulations of somatostatin influence on TSH dynamics investigated experimentally by Weeke et al. in 1975. In addition, all programs for SNA analysis were adapted for this kind of a large model. The procedure of calculating rate constants from steady-state reaction rates and very limited available experimental data was developed. For this purpose, a unique numerical method was developed to fine-tune model parameters while preserving the fixed rate ratios and using the magnitude of the experimentally known oscillation period as the only target value. The postulated model was numerically validated by perturbation simulations with somatostatin infusion and the results were compared with experiments available in literature. Finally, as far as we know, this reaction model with 15 variables is the most dimensional one that have been analysed mathematically to obtain instability region and oscillatory dynamic states. Among the existing models of thyroid homeostasis this theory represents a new class that may improve our understanding of basic physiological processes and helps to develop new therapeutic approaches. Additionally, it may pave the way to improved diagnostic methods for pituitary and thyroid disorders.
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Affiliation(s)
| | - Željko Čupić
- University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Serbia.
| | - Stevan Maćešić
- University of Belgrade, Faculty of Physical Chemistry, Serbia
| | - Ana Ivanović-Šašić
- University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Serbia
| | - Johannes W Dietrich
- Diabetes, Endocrinology and Metabolism Section, Department of Internal Medicine I, St. Josef Hospital, Ruhr University Bochum, Bochum, NRW, Germany; Diabetes Centre Bochum/Hattingen, St. Elisabeth Hospital Blankenstein, Hattingen, NRW, Germany; Centre for Rare Endocrine Diseases, Ruhr Centre for Rare Diseaeses (CeSER), Ruhr University of Bochum and Witten/Herdecke University, Bochum, NRW, Germany; Centre for Diabetes Technology, Catholic Hospitals Bochum, Hattingen, NRW, Germany
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Merakchi K, Djerbib S, Soleimani M, Dumont JE, Miot F, De Deken X. Murine Thyroid IL-4 Expression Worsens Hypothyroidism on Iodine Restriction and Mitigates Graves Disease Development. Endocrinology 2022; 163:6650252. [PMID: 35881515 DOI: 10.1210/endocr/bqac107] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Indexed: 11/19/2022]
Abstract
Cytokines are known to perturb thyroid function and the role of interleukin-4 (IL-4) in the pathogenesis of Graves disease (GD) remains controversial. In our mouse model overexpressing IL-4 in thyrocytes (Thyr-IL4), we have reported that adult mice preserved normal serum thyroxine despite an iodide uptake defect. In the present work, we evaluated if iodine restriction could uncover the thyroid deficiency in Thyr-IL4 animals as well as the role of pendrin overexpression as a compensatory mechanism. Moreover, using an experimental model of GD we investigated the effect of a local expression of IL-4 on the incidence of hyperthyroidism. Thyr-IL4 mice developed more rapidly elevated serum thyrotropin under low-iodine supply with thyroid enlargement and classical histological modifications. These hallmarks of hypothyroidism were all enhanced in Thyr-IL4 mice with complete pendrin invalidation. Following immunization, a lower proportion of Thyr-IL4 animals developed hyperthyroidism. Surprisingly, immunized Thyr-IL4 animals presented numerous leukocyte infiltrates, associated with increased intrathyroidal expression of IFN-γ. We have demonstrated that thyroid deficiency in Thyr-IL4 mice is partially compensated for by the excessive iodide content of the standard chow and the overexpression of pendrin in these animals. Furthermore, we have shown that the local expression of IL-4 in the thyroid attenuates GD progression, which was associated with enhanced thyroid infiltration by immune cells that could negatively affect thyroid function.
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Affiliation(s)
- Karima Merakchi
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Sami Djerbib
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Manoocher Soleimani
- Department of Medicine, University of New Mexico, School of Medicine, Albuquerque, New Mexico 87106, USA
| | - Jacques-Emile Dumont
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Françoise Miot
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Xavier De Deken
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
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Asghar MY, Lassila T, Törnquist K. Calcium Signaling in the Thyroid: Friend and Foe. Cancers (Basel) 2021; 13:cancers13091994. [PMID: 33919125 PMCID: PMC8122656 DOI: 10.3390/cancers13091994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary All cells in our body are activated by several different signals. The calcium ion is one of the most versatile signaling molecules, and regulates a multitude of different events in the cells. These range from activation of muscle contraction, to the regulation of cell movement, just to name a few. In normal thyroid cells, calcium signaling is of importance for the normal physiology of the cells. In thyroid pathologies, e.g., thyroid cancer, calcium is important for the regulation of proliferation and invasion, and may also activate gene transcription programs important for cancer cell survival. In this Commentary, we summarize what is known regarding calcium in the normal thyroid, and highlight the importance of calcium signaling in thyroid pathologies. Abstract Calcium signaling participates in a vast number of cellular processes, ranging from the regulation of muscle contraction, cell proliferation, and mitochondrial function, to the regulation of the membrane potential in cells. The actions of calcium signaling are, thus, of great physiological significance for the normal functioning of our cells. However, many of the processes that are regulated by calcium, including cell movement and proliferation, are important in the progression of cancer. In the normal thyroid, calcium signaling plays an important role, and evidence is also being gathered showing that calcium signaling participates in the progression of thyroid cancer. This review will summarize what we know in regard to calcium signaling in the normal thyroid as, well as in thyroid cancer.
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Affiliation(s)
- Muhammad Yasir Asghar
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland; (M.Y.A.); (T.L.)
| | - Taru Lassila
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland; (M.Y.A.); (T.L.)
- Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, 00250 Turku, Finland
| | - Kid Törnquist
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland; (M.Y.A.); (T.L.)
- Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, 00250 Turku, Finland
- Correspondence:
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4
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Wasano K, Takahashi S, Rosenberg SK, Kojima T, Mutai H, Matsunaga T, Ogawa K, Homma K. Systematic quantification of the anion transport function of pendrin (SLC26A4) and its disease-associated variants. Hum Mutat 2020; 41:316-331. [PMID: 31599023 PMCID: PMC6930342 DOI: 10.1002/humu.23930] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 01/14/2023]
Abstract
Thanks to the advent of rapid DNA sequencing technology and its prevalence, many disease-associated genetic variants are rapidly identified in many genes from patient samples. However, the subsequent effort to experimentally validate and define their pathological roles is extremely slow. Consequently, the pathogenicity of most disease-associated genetic variants is solely speculated in silico, which is no longer deemed compelling. We developed an experimental approach to efficiently quantify the pathogenic effects of disease-associated genetic variants with a focus on SLC26A4, which is essential for normal inner ear function. Alterations of this gene are associated with both syndromic and nonsyndromic hereditary hearing loss with various degrees of severity. We established HEK293T-based stable cell lines that express pendrin missense variants in a doxycycline-dependent manner, and systematically determined their anion transport activities with high accuracy in a 96-well plate format using a high throughput plate reader. Our doxycycline dosage-dependent transport assay objectively distinguishes missense variants that indeed impair the function of pendrin from those that do not (functional variants). We also found that some of these putative missense variants disrupt normal messenger RNA splicing. Our comprehensive experimental approach helps determine the pathogenicity of each pendrin variant, which should guide future efforts to benefit patients.
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Affiliation(s)
- Koichiro Wasano
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Satoe Takahashi
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Samuel K. Rosenberg
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Takashi Kojima
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Hideki Mutai
- Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Tatsuo Matsunaga
- Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Kaoru Ogawa
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kazuaki Homma
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- The Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University, Evanston, IL 60608, USA
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Zhao Y, Zhong L, Yi H. A review on the mechanism of iodide metabolic dysfunction in differentiated thyroid cancer. Mol Cell Endocrinol 2019; 479:71-77. [PMID: 30287400 DOI: 10.1016/j.mce.2018.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 12/27/2022]
Abstract
The incidence of differentiated thyroid cancer (DTC) has been increasing rapidly worldwide, and the risk factors remain unclear. With the growing number of patients with DTC, the related issues have been gradually highlighted. 131Iodide (131I) is an important treatment for DTC and has the potential to reduce the risk of recurrence. 131I is also an effective treatment for distant metastases of thyroid carcinoma. However, iodide metabolism dysfunction in metastatic foci causes patients to lose the opportunity of 131I treatment. This article reviews the related mechanisms of iodide metabolism dysfunction in DTC cells and summarizes the clinical transformation progression.
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Affiliation(s)
- Yinlong Zhao
- Department of Nuclear Medicine, Second Hospital of Jilin University, Changchun, Jilin Province, 130041, PR China.
| | - Lili Zhong
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, Second Hospital of Jilin University, Changchun, 130041, PR China.
| | - Heqing Yi
- Department of Nuclear Medicine, Zhejiang Cancer Hospital, Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang, 310021, PR China.
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Abstract
Pendred syndrome is an autosomal recessive disorder that is classically defined by the combination of sensorineural deafness/hearing impairment, goiter, and an abnormal organification of iodide with or without hypothyroidism. The hallmark of the syndrome is the impaired hearing, which is associated with inner ear malformations such as an enlarged vestibular aqueduct (EVA). The thyroid phenotype is variable and may be modified by the nutritional iodine intake. Pendred syndrome is caused by biallelic mutations in the SLC26A4/PDS gene, which encodes the multifunctional anion exchanger pendrin. Pendrin has affinity for chloride, iodide, and bicarbonate, among other anions. In the inner ear, pendrin functions as a chloride/bicarbonate exchanger that is essential for maintaining the composition and the potential of the endolymph. In the thyroid, pendrin is expressed at the apical membrane of thyroid cells facing the follicular lumen. Functional studies have demonstrated that pendrin can mediate iodide efflux in heterologous cells. This, together with the thyroid phenotype observed in humans (goiter, impaired iodine organification) suggests that pendrin could be involved in iodide efflux into the lumen, one of the steps required for thyroid hormone synthesis. Iodide efflux can, however, also occur in the absence of pendrin suggesting that other exchangers or channels are involved. It has been suggested that Anoctamin 1 (ANO1/TMEM16A), a calcium-activated anion channel, which is also expressed at the apical membrane of thyrocytes, could participate in mediating apical efflux. In the kidney, pendrin is involved in bicarbonate secretion and chloride reabsorption. While there is no renal phenotype under basal conditions, severe metabolic alkalosis has been reported in Pendred syndrome patients exposed to an increased alkali load. This review provides an overview on the clinical spectrum of Pendred syndrome, the functional data on pendrin with a focus on its potential role in the thyroid, as well as the controversy surrounding the relative physiological roles of pendrin and anoctamin.
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Affiliation(s)
- Jean-Louis Wémeau
- Université de Lille 2, Centre Hospitalier Régional Universitaire de Lille, Clinique Endocrinologique Marc-Linquette, 59037 Lille, France.
| | - Peter Kopp
- Northwestern University, Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Tarry 15, 303 East Chicago Avenue, Chicago, IL 60611, USA.
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7
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Eskalli Z, Achouri Y, Hahn S, Many MC, Craps J, Refetoff S, Liao XH, Dumont JE, Van Sande J, Corvilain B, Miot F, De Deken X. Overexpression of Interleukin-4 in the Thyroid of Transgenic Mice Upregulates the Expression of Duox1 and the Anion Transporter Pendrin. Thyroid 2016; 26:1499-1512. [PMID: 27599561 PMCID: PMC5067804 DOI: 10.1089/thy.2016.0106] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The dual oxidases (Duox) are involved in hydrogen peroxide generation, which is essential for thyroid hormone synthesis, and therefore they are markers of thyroid function. During inflammation, cytokines upregulate DUOX gene expression in the airway and the intestine, suggesting a role for these proteins in innate immunity. It was previously demonstrated that interleukin-4 (IL-4) upregulates DUOX gene expression in thyrocytes. Although the role of IL-4 in autoimmune thyroid diseases has been studied extensively, the effects of IL-4 on thyroid physiology remain largely unknown. Therefore, a new animal model was generated to study the impact of IL-4 on thyroid function. METHODS Transgenic (Thyr-IL-4) mice with thyroid-targeted expression of murine IL-4 were generated. Transgene expression was verified at the mRNA and protein level in thyroid tissues and primary cultures. The phenotype of the Thyr-IL-4 animals was characterized by measuring serum thyroxine (T4) and thyrotropin levels and performing thyroid morphometric analysis, immunohistochemistry, whole transcriptome sequencing, quantitative reverse transcription polymerase chain reaction, and ex vivo thyroid function assays. RESULTS Thyrocytes from two Thyr-IL-4 mouse lines (#30 and #52) expressed IL-4, which was secreted into the extracellular space. Although 10-month-old transgenic animals had T4 and thyrotropin serum levels in the normal range, they had altered thyroid follicular structure with enlarged follicles composed of elongated thyrocytes containing numerous endocytic vesicles. These follicles were positive for T4 staining the colloid, indicating their capacity to produce thyroid hormones. RNA profiling of Thyr-IL-4 thyroid samples revealed modulation of multiple genes involved in inflammation, while no major leukocyte infiltration could be detected. Upregulated expression of Duox1, Duoxa1, and the pendrin anion exchanger gene (Slc26a4) was detected. In contrast, the iodide symporter gene Slc5a5 was markedly downregulated resulting in impaired iodide uptake and reduced thyroid hormone levels in transgenic thyroid tissue. Hydrogen peroxide production was increased in Thyr-IL-4 thyroid tissue compared with wild-type animals, but no significant oxidative stress could be detected. CONCLUSIONS This is the first study to show that ectopic expression of IL-4 in thyroid tissue upregulates Duox1/Duoxa1 and Slc26a4 expression in the thyroid. The present data demonstrate that IL-4 could affect thyroid morphology and function, mainly by downregulating Slc5a5 expression, while maintaining a normal euthyroid phenotype.
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Affiliation(s)
- Zineb Eskalli
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Younes Achouri
- Institut De Duve, Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Stephan Hahn
- Laboratory of Image, Signal processing and Acoustics—Brussels School of Engineering, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Marie-Christine Many
- Pôle de Morphologie (MORF), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Julie Craps
- Pôle de Morphologie (MORF), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Samuel Refetoff
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Xiao-Hui Liao
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Jacques E. Dumont
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Jacqueline Van Sande
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles (ULB), Brussels, Belgium
| | | | - Françoise Miot
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Xavier De Deken
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles (ULB), Brussels, Belgium
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8
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Lakshmanan A, Scarberry D, Green JA, Zhang X, Selmi-Ruby S, Jhiang SM. Modulation of thyroidal radioiodide uptake by oncological pipeline inhibitors and Apigenin. Oncotarget 2016; 6:31792-804. [PMID: 26397139 PMCID: PMC4741640 DOI: 10.18632/oncotarget.5172] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 08/27/2015] [Indexed: 12/26/2022] Open
Abstract
Targeted radioiodine therapy for thyroid cancer is based on selective stimulation of Na+/I- Symporter (NIS)-mediated radioactive iodide uptake (RAIU) in thyroid cells by thyrotropin. Patients with advanced thyroid cancer do not benefit from radioiodine therapy due to reduced or absent NIS expression. To identify inhibitors that can be readily translated into clinical care, we examined oncological pipeline inhibitors targeting Akt, MEK, PI3K, Hsp90 or BRAF in their ability to increase RAIU in thyroid cells expressing BRAFV600E or RET/PTC3 oncogene. Our data showed that (1) PI3K inhibitor GDC-0941 outperformed other inhibitors in RAIU increase mainly by decreasing iodide efflux rate to a great extent; (2) RAIU increase by all inhibitors was extensively reduced by TGF-β, a cytokine secreted in the invasive fronts of thyroid cancers; (3) RAIU reduction by TGF-β was mainly mediated by NIS reduction and could be reversed by Apigenin, a plant-derived flavonoid; and (4) In the presence of TGF-β, GDC-0941 with Apigenin co-treatment had the highest RAIU level in both BRAFV600E expressing cells and RET/PTC3 expressing cells. Taken together, Apigenin may serve as a dietary supplement along with small molecule inhibitors to improve radioiodine therapeutic efficacy on invasive tumor margins thereby minimizing future metastatic events.
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Affiliation(s)
- Aparna Lakshmanan
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH-43210, USA.,Molecular, Cellular and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH-43210, USA
| | - Daniel Scarberry
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH-43210, USA.,Molecular, Cellular and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH-43210, USA
| | - Jill A Green
- Comprehensive Cancer Center, The Ohio State University, Columbus, OH-43210, USA
| | - Xiaoli Zhang
- Center for Biostatistics, The Ohio State University, Columbus, OH-43210, USA
| | - Samia Selmi-Ruby
- Centre de Recherche en Cancérologie de LYON (CRCL)-UMR 1052-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de LYON, F-69372, France
| | - Sissy M Jhiang
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH-43210, USA.,Molecular, Cellular and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH-43210, USA.,Comprehensive Cancer Center, The Ohio State University, Columbus, OH-43210, USA
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9
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Gnocchi D, Steffensen KR, Bruscalupi G, Parini P. Emerging role of thyroid hormone metabolites. Acta Physiol (Oxf) 2016; 217:184-216. [PMID: 26748938 DOI: 10.1111/apha.12648] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/28/2015] [Accepted: 01/03/2016] [Indexed: 12/15/2022]
Abstract
Thyroid hormones (THs) are essential for the regulation of development and metabolism in key organs. THs produce biological effects both by directly affecting gene expression through the interaction with nuclear receptors (genomic effects) and by activating protein kinases and/or ion channels (short-term effects). Such activations can be either direct, in the case of ion channels, or mediated by membrane or cytoplasmic receptors. Short-term-activated signalling pathways often play a role in the regulation of genomic effects. Several TH intermediate metabolites, which were previously considered without biological activity, have now been associated with a broad range of actions, mostly attributable to short-term effects. Here, we give an overview of the physiological roles and mechanisms of action of THs, focusing on the emerging position that TH metabolites are acquiring as important regulators of physiology and metabolism.
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Affiliation(s)
- D. Gnocchi
- Division of Clinical Chemistry; Department of Laboratory Medicine; Karolinska Institutet at Karolinska University Hospital Huddinge; Stockholm Sweden
| | - K. R. Steffensen
- Division of Clinical Chemistry; Department of Laboratory Medicine; Karolinska Institutet at Karolinska University Hospital Huddinge; Stockholm Sweden
| | - G. Bruscalupi
- Department of Biology and Biotechnology ‘Charles Darwin’; Sapienza University of Rome; Rome Italy
| | - P. Parini
- Division of Clinical Chemistry; Department of Laboratory Medicine; Karolinska Institutet at Karolinska University Hospital Huddinge; Stockholm Sweden
- Metabolism Unit; Department of Medicine; Karolinska Institutet at Karolinska University Hospital Huddinge; Stockholm Sweden
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10
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Twyffels L, Strickaert A, Virreira M, Massart C, Van Sande J, Wauquier C, Beauwens R, Dumont JE, Galietta LJ, Boom A, Kruys V. Anoctamin-1/TMEM16A is the major apical iodide channel of the thyrocyte. Am J Physiol Cell Physiol 2014; 307:C1102-12. [PMID: 25298423 DOI: 10.1152/ajpcell.00126.2014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Iodide is captured by thyrocytes through the Na(+)/I(-) symporter (NIS) before being released into the follicular lumen, where it is oxidized and incorporated into thyroglobulin for the production of thyroid hormones. Several reports point to pendrin as a candidate protein for iodide export from thyroid cells into the follicular lumen. Here, we show that a recently discovered Ca(2+)-activated anion channel, TMEM16A or anoctamin-1 (ANO1), also exports iodide from rat thyroid cell lines and from HEK 293T cells expressing human NIS and ANO1. The Ano1 mRNA is expressed in PCCl3 and FRTL-5 rat thyroid cell lines, and this expression is stimulated by thyrotropin (TSH) in rat in vivo, leading to the accumulation of the ANO1 protein at the apical membrane of thyroid follicles. Moreover, ANO1 properties, i.e., activation by intracellular calcium (i.e., by ionomycin or by ATP), low but positive affinity for pertechnetate, and nonrequirement for chloride, better fit with the iodide release characteristics of PCCl3 and FRTL-5 rat thyroid cell lines than the dissimilar properties of pendrin. Most importantly, iodide release by PCCl3 and FRTL-5 cells is efficiently blocked by T16Ainh-A01, an ANO1-specific inhibitor, and upon ANO1 knockdown by RNA interference. Finally, we show that the T16Ainh-A01 inhibitor efficiently blocks ATP-induced iodide efflux from in vitro-cultured human thyrocytes. In conclusion, our data strongly suggest that ANO1 is responsible for most of the iodide efflux across the apical membrane of thyroid cells.
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Affiliation(s)
- L Twyffels
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium; Center for Microscopy and Molecular Imaging, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - A Strickaert
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - M Virreira
- Laboratoire de Physiologie Moléculaire et Cellulaire, Faculté de Médecine, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - C Massart
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - J Van Sande
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - C Wauquier
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - R Beauwens
- Laboratoire de Physiologie Moléculaire et Cellulaire, Faculté de Médecine, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - J E Dumont
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université libre de Bruxelles (ULB), Brussels, Belgium;
| | - L J Galietta
- Laboratory of Molecular Genetics, Istituto Giannina Gaslini, Genoa, Italy
| | - A Boom
- Laboratoire de Physiologie Moléculaire et Cellulaire, Faculté de Médecine, Université libre de Bruxelles (ULB), Brussels, Belgium; Laboratoire d'Histologie, Histopathologie et Neuroanatomie, Faculté de Médecine, Université libre de Bruxelles (ULB), Brussels, Belgium; and
| | - V Kruys
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium; Center for Microscopy and Molecular Imaging, Université libre de Bruxelles (ULB), Brussels, Belgium
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Canonical transient receptor potential channel 2 (TRPC2): old name-new games. Importance in regulating of rat thyroid cell physiology. Pflugers Arch 2014; 466:2025-34. [PMID: 24722829 DOI: 10.1007/s00424-014-1509-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 03/25/2014] [Accepted: 03/26/2014] [Indexed: 12/14/2022]
Abstract
In addition to the TSH-cyclic AMP signalling pathway, calcium signalling is of crucial importance in thyroid cells. Although the importance of calcium signalling has been thoroughly investigated for several decades, the nature of the calcium channels involved in signalling is unknown. In a recent series of investigations using the well-studied rat thyroid FRTL-5 cell line, we showed that these cells exclusively express the transient receptor potential canonical 2 (TRPC2) channel. Our results suggested that the TRPC2 channel is of significant importance in regulating thyroid cell function. These investigations were the first to show that thyroid cells express a member of the TRPC family of ion channels. In this review, we will describe the importance of the TRPC2 channel in regulating TSH receptor expression, thyroglobulin maturation, intracellular calcium and iodide homeostasis and that the channel also regulates thyroid cell proliferation.
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McLanahan ED, White P, Flowers L, Schlosser PM. The use of PBPK models to inform human health risk assessment: case study on perchlorate and radioiodide human lifestage models. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2014; 34:356-366. [PMID: 23901895 DOI: 10.1111/risa.12101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Physiologically-based pharmacokinetic (PBPK) models are often submitted to or selected by agencies, such as the U.S. Environmental Protection Agency (U.S. EPA) and Agency for Toxic Substances and Disease Registry, for consideration for application in human health risk assessment (HHRA). Recently, U.S. EPA evaluated the human PBPK models for perchlorate and radioiodide for their ability to estimate the relative sensitivity of perchlorate inhibition on thyroidal radioiodide uptake for various population groups and lifestages. The most well-defined mode of action of the environmental contaminant, perchlorate, is competitive inhibition of thyroidal iodide uptake by the sodium-iodide symporter (NIS). In this analysis, a six-step framework for PBPK model evaluation was followed, and with a few modifications, the models were determined to be suitable for use in HHRA to evaluate relative sensitivity among human lifestages. Relative sensitivity to perchlorate was determined by comparing the PBPK model predicted percent inhibition of thyroidal radioactive iodide uptake (RAIU) by perchlorate for different lifestages. A limited sensitivity analysis indicated that model parameters describing urinary excretion of perchlorate and iodide were particularly important in prediction of RAIU inhibition; therefore, a range of biologically plausible values available in the peer-reviewed literature was evaluated. Using the updated PBPK models, the greatest sensitivity to RAIU inhibition was predicted to be the near-term fetus (gestation week 40) compared to the average adult and other lifestages; however, when exposure factors were taken into account, newborns were found to be populations that need further evaluation and consideration in a risk assessment for perchlorate.
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Affiliation(s)
- Eva D McLanahan
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Research Triangle Park, NC, USA
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Kopp P. Mutations in the Pendred Syndrome (PDS/SLC26A) gene: an increasingly complex phenotypic spectrum from goiter to thyroid hypoplasia. J Clin Endocrinol Metab 2014; 99:67-9. [PMID: 24384016 DOI: 10.1210/jc.2013-4319] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Peter Kopp
- Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
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15
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Kühnen P, Turan S, Fröhler S, Güran T, Abali S, Biebermann H, Bereket A, Grüters A, Chen W, Krude H. Identification of PENDRIN (SLC26A4) mutations in patients with congenital hypothyroidism and "apparent" thyroid dysgenesis. J Clin Endocrinol Metab 2014; 99:E169-76. [PMID: 24248179 DOI: 10.1210/jc.2013-2619] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Congenital hypothyroidism, the most frequent endocrine congenital disease, can occur either based on a thyroid hormone biosynthesis defect or can predominantly be due to thyroid dysgenesis. However, a genetic cause could so far only be identified in less than 10% of patients with a thyroid dysgenesis. OBJECTIVES Exome sequencing was used for the first time to find additional genetic defects in thyroid dysgenesis. PATIENTS AND METHODS In a consanguineous family with thyroid dysgenesis, exome sequencing was applied, and findings were further validated by Sanger sequencing in a cohort of 94 patients with thyroid dysgenesis. RESULTS By exome sequencing we identified a homozygous missense mutation (p.Leu597Ser) in the SLC26A4 gene of a patient with hypoplastic thyroid tissue, who was otherwise healthy. In the cohort of patients with thyroid dysgenesis, we observed a second case with a homozygous missense mutation (p.Gln413Arg) in the SLC26A4 gene, who was additionally affected by severe hearing problems. Both mutations were previously described as loss-of-function mutations in patients with Pendred syndrome and nonsyndromic enlarged vestibular aqueduct. CONCLUSION We unexpectedly identified SLC26A4 mutations that were hitherto diagnosed in thyroid dyshormonogenesis patients, now for the first time in patients with structural thyroid defects. This result resembles the historic description of thyroid atrophy in patients with the so-called myxedematous form of cretinism after severe iodine deficiency. Most likely the thyroid defect of the two homozygous SLC26A4 gene mutation carriers represents a kind of secondary thyroid atrophy, rather than a primary defect of thyroid development in the sense of thyroid agenesis. Our study extends the variable clinical spectrum of patients with SLC26A4 mutations and points out the necessity to analyze the SLC26A4 gene in patients with apparent thyroid dysgenesis in addition to the known candidate genes TSHR, PAX8, NKX2.1, NKX2.5, and FOXE1.
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Affiliation(s)
- Peter Kühnen
- Institute of Experimental Pediatric Endocrinology (P.K., H.B., A.G., H.K.), Charité Universitätsmedizin Berlin, 13353 Berlin, Germany; Department of Pediatric Endocrinology and Diabetes (S.T., T.G., S.A., A.B.), Marmara University Hospital, 34722 Istanbul, Turkey; and Max-Delbrück Center for Molecular Medicine (S.F., W.C.), 13092 Berlin-Buch, Germany
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Massart C, Giusti N, Beauwens R, Dumont JE, Miot F, Sande JV. Diphenyleneiodonium, an inhibitor of NOXes and DUOXes, is also an iodide-specific transporter. FEBS Open Bio 2013; 4:55-9. [PMID: 24371722 PMCID: PMC3871273 DOI: 10.1016/j.fob.2013.11.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/07/2013] [Accepted: 11/28/2013] [Indexed: 01/22/2023] Open
Abstract
NADPH oxidases (NOXes) and dual oxidases (DUOXes) generate O2 (.-) and H2O2. Diphenyleneiodonium (DPI) inhibits the activity of these enzymes and is often used as a specific inhibitor. It is shown here that DPI, at concentrations similar to those which inhibit the generation of O2 derivatives, activated the efflux of radioiodide but not of its analog (99m)TcO4 (-) nor of the K(+) cation mimic (86)Rb(+) in thyroid cells, in the PCCl3 rat thyroid cell line and in COS cell lines expressing the iodide transporter NIS. Effects obtained with DPI, especially in thyroid cells, should therefore be interpreted with caution.
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Affiliation(s)
- C Massart
- IRIBHM, School of Medicine, ULB, Université Libre de Bruxelles, Campus Erasme, Route de Lennik 808, Belgium
| | - N Giusti
- IRIBHM, School of Medicine, ULB, Université Libre de Bruxelles, Campus Erasme, Route de Lennik 808, Belgium
| | - R Beauwens
- Laboratory of Physiology, School of Medicine, ULB, Université Libre de Bruxelles, Campus Erasme, Route de Lennik 808, Belgium
| | - J E Dumont
- IRIBHM, School of Medicine, ULB, Université Libre de Bruxelles, Campus Erasme, Route de Lennik 808, Belgium
| | - F Miot
- IRIBHM, School of Medicine, ULB, Université Libre de Bruxelles, Campus Erasme, Route de Lennik 808, Belgium
| | - J Van Sande
- IRIBHM, School of Medicine, ULB, Université Libre de Bruxelles, Campus Erasme, Route de Lennik 808, Belgium
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Zane M, Agostini M, Enzo MV, Casal Ide E, Del Bianco P, Torresan F, Merante Boschin I, Pennelli G, Saccani A, Rubello D, Nitti D, Pelizzo MR. Circulating cell-free DNA, SLC5A8 and SLC26A4 hypermethylation, BRAF(V600E): A non-invasive tool panel for early detection of thyroid cancer. Biomed Pharmacother 2013; 67:723-30. [PMID: 23931930 DOI: 10.1016/j.biopha.2013.06.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 06/24/2013] [Indexed: 01/05/2023] Open
Abstract
PURPOSE In the latest years, high levels of circulating cell-free DNA (cf-DNA) have been found to be associated with cancer diagnosis and progression, and cf-DNA has become a potential candidate as biomarker for tumor detection. cf-DNA has been investigated in plasma or serum of many tumor patients affected by different malignancies, but not yet in thyroid cancer (TC). Furthermore, in TC cells the capability to metabolize iodine is frequently lost. SLC5A8 and SLC26A4 genes are both involved in the iodine metabolism, and SLC5A8 hypermethylation status is associated with the BRAF(V600E) mutation, which is the most frequent genetic event underlying the development of papillary TC. The aim of our study is the development of a new non-invasive tool for the diagnosis and prognosis of TC based on cf-DNA, SLC5A8 and SLC26A4 hypermethylation, and BRAF(V600E) analysis. METHODS cf-DNA was measured by quantitative real-time PCR in nine cases of anaplastic thyroid cancer (ATC), 58 medullary thyroid cancers (MTC), five of synchronous medullary and follicular thyroid cancers (SMFC), 23 follicular adenomas (FA), 86 papillary thyroid cancers (PTC). A control group of 19 healthy subjects was taken. Moreover, in the PTC group we analyze the state of hypermethylation of SLC5A8 and SLC26A4, BRAF(V600E) mutation, and their involvement in the loss of function of the thyroid. RESULTS cf-DNA showed a high ability to discriminate healthy individuals from cancer patients. cf-DNAALU83 and cf-DNAALU244 values were significantly correlated with the histological type of TC (P-value < 0.0001). A significant increase in the amount of cf-DNAALU83 and cf-DNAALU244 when methylation occurs was observed (P-value = 0.02). A correlation between BRAF(V600E) and cf-DNAALU244/ALU83 was also found (P-value = 0.02). CONCLUSIONS According to our experimental results, the panel including cf-DNA, SLC5A8 and SLC26A4 hypermethylation, and BRAF(V600E) analysis appears easy, reproducible, and non-invasive for the diagnosis on TC. Its possible implication in clinical setting remains to be elucidated.
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Affiliation(s)
- Mariangela Zane
- Surgical clinic II, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Padova, Italy
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Efficacy of lentiviral-mediated transfection of hTSHR in poorly differentiated thyroid carcinoma cell line. Nucl Med Biol 2013; 40:576-80. [DOI: 10.1016/j.nucmedbio.2012.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 11/19/2012] [Accepted: 12/03/2012] [Indexed: 11/22/2022]
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Colin IM, Denef JF, Lengelé B, Many MC, Gérard AC. Recent insights into the cell biology of thyroid angiofollicular units. Endocr Rev 2013; 34:209-38. [PMID: 23349248 PMCID: PMC3610675 DOI: 10.1210/er.2012-1015] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 11/07/2012] [Indexed: 01/06/2023]
Abstract
In thyrocytes, cell polarity is of crucial importance for proper thyroid function. Many intrinsic mechanisms of self-regulation control how the key players involved in thyroid hormone (TH) biosynthesis interact in apical microvilli, so that hazardous biochemical processes may occur without detriment to the cell. In some pathological conditions, this enzymatic complex is disrupted, with some components abnormally activated into the cytoplasm, which can lead to further morphological and functional breakdown. When iodine intake is altered, autoregulatory mechanisms outside the thyrocytes are activated. They involve adjacent capillaries that, together with thyrocytes, form the angiofollicular units (AFUs) that can be considered as the functional and morphological units of the thyroid. In response to iodine shortage, a rapid expansion of the microvasculature occurs, which, in addition to nutrients and oxygen, optimizes iodide supply. These changes are triggered by angiogenic signals released from thyrocytes via a reactive oxygen species/hypoxia-inducible factor/vascular endothelial growth factor pathway. When intra- and extrathyrocyte autoregulation fails, other forms of adaptation arise, such as euthyroid goiters. From onset, goiters are morphologically and functionally heterogeneous due to the polyclonal nature of the cells, with nodules distributed around areas of quiescent AFUs containing globules of compact thyroglobulin (Tg) and surrounded by a hypotrophic microvasculature. Upon TSH stimulation, quiescent AFUs are activated with Tg globules undergoing fragmentation into soluble Tg, proteins involved in TH biosynthesis being expressed and the local microvascular network extending. Over time and depending on physiological needs, AFUs may undergo repetitive phases of high, moderate, or low cell and tissue activity, which may ultimately culminate in multinodular goiters.
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Affiliation(s)
- Ides M Colin
- Pôle de Morphologie, Institut de Recherche Expérimentale et Clinique, Secteur des Sciences de la Santé, Université Catholique de Louvain (UCL), UCL-5251, 52 Avenue E. Mounier, B-1200, Bruxelles, Belgium.
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Degrelle S, Guibourdenche J, Galland F, Bidart J, Fournier T, Evain-Brion D. Iodide transporters expression in early human invasive trophoblast. Placenta 2013; 34:29-34. [DOI: 10.1016/j.placenta.2012.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/09/2012] [Accepted: 11/01/2012] [Indexed: 11/17/2022]
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Pelzl L, Pakladok T, Pathare G, Fakhri H, Michael D, Wagner CA, Paulmichl M, Lang F. DOCA sensitive pendrin expression in kidney, heart, lung and thyroid tissues. Cell Physiol Biochem 2012; 30:1491-501. [PMID: 23235354 DOI: 10.1159/000343337] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND/AIMS Pendrin (SLC26A4), a transporter accomplishing anion exchange, is expressed in inner ear, thyroid gland, kidneys, lung, liver and heart. Loss or reduction of function mutations of SLC26A4 underlie Pendred syndrome, a disorder invariably leading to hearing loss with enlarged vestibular aqueducts and in some patients to hypothyroidism and goiter. Renal pendrin expression is up-regulated by mineralocorticoids such as aldosterone or deoxycorticosterone (DOCA). Little is known about the impact of mineralocorticoids on pendrin expression in extrarenal tissues. METHODS The present study utilized RT-qPCR and Western blotting to quantify the transcript levels and protein abundance of Slc26a4 in murine kidney, thyroid, heart and lung prior to and following subcutaneous administration of 100 mg/kg DOCA. RESULTS Slc26a4 transcript levels as compared to Gapdh transcript levels were significantly increased by DOCA treatment in kidney, heart, lung and thyroid. Accordingly pendrin protein expression was again significantly increased by DOCA treatment in kidney, heart, lung and thyroid. CONCLUSION The observations reveal mineralocorticoid sensitivity of pendrin expression in kidney, heart, thyroid and lung.
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Affiliation(s)
- Lisann Pelzl
- Department of Physiology, University of Tuebingen, Tuebingen, Germany
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Dossena S, Nofziger C, Tamma G, Bernardinelli E, Vanoni S, Nowak C, Grabmayer E, Kössler S, Stephan S, Patsch W, Paulmichl M. Molecular and functional characterization of human pendrin and its allelic variants. Cell Physiol Biochem 2011; 28:451-66. [PMID: 22116358 DOI: 10.1159/000335107] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2011] [Indexed: 12/13/2022] Open
Abstract
Pendrin (SLC26A4, PDS) is an electroneutral anion exchanger transporting I(-), Cl(-), HCO(3)(-), OH(-), SCN(-) and formate. In the thyroid, pendrin is expressed at the apical membrane of the follicular epithelium and may be involved in mediating apical iodide efflux into the follicle; in the inner ear, it plays a crucial role in the conditioning of the pH and ion composition of the endolymph; in the kidney, it may exert a role in pH homeostasis and regulation of blood pressure. Mutations of the pendrin gene can lead to syndromic and non-syndromic hearing loss with EVA (enlarged vestibular aqueduct). Functional tests of mutated pendrin allelic variants found in patients with Pendred syndrome or non-syndromic EVA (ns-EVA) revealed that the pathological phenotype is due to the reduction or loss of function of the ion transport activity. The diagnosis of Pendred syndrome and ns-EVA can be difficult because of the presence of phenocopies of Pendred syndrome and benign polymorphisms occurring in the general population. As a consequence, defining whether or not an allelic variant is pathogenic is crucial. Recently, we found that the two parameters used so far to assess the pathogenic potential of a mutation, i.e. low incidence in the control population, and substitution of evolutionary conserved amino acids, are not always reliable for predicting the functionality of pendrin allelic variants; actually, we identified mutations occurring with the same frequency in the cohort of hearing impaired patients and in the control group of normal hearing individuals. Moreover, we identified functional polymorphisms affecting highly conserved amino acids. As a general rule however, we observed a complete loss of function for all truncations and amino acid substitutions involving a proline. In this view, clinical and radiological studies should be combined with genetic and molecular studies for a definitive diagnosis. In performing genetic studies, the possibility that the mutation could affect regions other than the pendrin coding region, such as its promoter region and/or the coding regions of functionally related genes (FOXI1, KCNJ10), should be taken into account. The presence of benign polymorphisms in the population suggests that genetic studies should be corroborated by functional studies; in this context, the existence of hypo-functional variants and possible differences between the I(-)/Cl(-) and Cl(-)/HCO(3)(-) exchange activities should be carefully evaluated.
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Affiliation(s)
- Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria.
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Dossena S, Nofziger C, Lang F, Valenti G, Paulmichl M. The ESF meeting on "The proteomics, epigenetics and pharmacogenetics of pendrin". Cell Physiol Biochem 2011; 28:377-84. [PMID: 22116352 DOI: 10.1159/000335101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2011] [Indexed: 12/25/2022] Open
Abstract
Human pendrin (SCL26A4, PDS) is a 780 amino acid integral membrane protein with transport function. It acts as an electroneutral, sodium-independent anion exchanger for a wide range of anions, such as iodide, chloride, formate, bicarbonate, hydroxide and thiocyanate. Pendrin expression was originally described in the thyroid gland, kidney and inner ear. Accordingly, pendrin mutations with reduction or loss of transport function result in thyroid and inner ear abnormalities, manifested as syndromic (Pendred syndrome) and non-syndromic hearing loss with an enlarged vestibular aqueduct (ns-EVA). Pendred syndrome, the most common form of syndromic deafness, is an autosomal recessive disease characterized by sensorineural deafness due to inner ear malformations and a partial iodide organification defect that may lead to thyroid goiter. Later, it became evident that not only pendrin loss of function, but also up-regulation could participate in the pathogenesis of human diseases. Indeed, despite the absence of kidney dysfunction in Pendred syndrome patients, evidence exists that pendrin also plays a crucial role in this organ, with a potential involvement in the pathogenesis of hypertension. In addition, recent data underscore the role of pendrin in exacerbations of respiratory distresses including bronchial asthma and chronic obstructive pulmonary disease (COPD). Pendrin expression in other organs such as mammary gland, testis, placenta, endometrium and liver point to new, underscored pendrin functions that deserve to be further investigated.
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Affiliation(s)
- Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
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