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Medici M, Visser WE, Visser TJ, Peeters RP. Genetic determination of the hypothalamic-pituitary-thyroid axis: where do we stand? Endocr Rev 2015; 36:214-44. [PMID: 25751422 DOI: 10.1210/er.2014-1081] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
For a long time it has been known that both hypo- and hyperthyroidism are associated with an increased risk of morbidity and mortality. In recent years, it has also become clear that minor variations in thyroid function, including subclinical dysfunction and variation in thyroid function within the reference range, can have important effects on clinical endpoints, such as bone mineral density, depression, metabolic syndrome, and cardiovascular mortality. Serum thyroid parameters show substantial interindividual variability, whereas the intraindividual variability lies within a narrow range. This suggests that every individual has a unique hypothalamus-pituitary-thyroid axis setpoint that is mainly determined by genetic factors, and this heritability has been estimated to be 40-60%. Various mutations in thyroid hormone pathway genes have been identified in persons with thyroid dysfunction or altered thyroid function tests. Because these causes are rare, many candidate gene and linkage studies have been performed over the years to identify more common variants (polymorphisms) associated with thyroid (dys)function, but only a limited number of consistent associations have been found. However, in the past 5 years, advances in genetic research have led to the identification of a large number of new candidate genes. In this review, we provide an overview of the current knowledge about the polygenic basis of thyroid (dys)function. This includes new candidate genes identified by genome-wide approaches, what insights these genes provide into the genetic basis of thyroid (dys)function, and which new techniques will help to further decipher the genetic basis of thyroid (dys)function in the near future.
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Affiliation(s)
- Marco Medici
- Rotterdam Thyroid Center, Department of Internal Medicine, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands
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Fukushima T, Nedachi T, Akizawa H, Akahori M, Hakuno F, Takahashi SI. Distinct modes of activation of phosphatidylinositol 3-kinase in response to cyclic adenosine 3', 5'-monophosphate or insulin-like growth factor I play different roles in regulation of cyclin D1 and p27Kip1 in FRTL-5 cells. Endocrinology 2008; 149:3729-42. [PMID: 18403485 DOI: 10.1210/en.2007-1443] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bioactivities of IGFs in various cells are often potentiated in the presence of other hormones. In previous studies we showed that pretreatment of rat FRTL-5 thyroid cells with TSH or other cAMP-generating agents markedly potentiated DNA synthesis induced by IGF-I. Under these conditions we found that phosphatidylinositol (PI) 3-kinase was activated in response to either cAMP or IGF stimulus, and both activation modes were indispensable for the potentiation of DNA synthesis. The present studies were undertaken to elucidate how cAMP and/or IGF-I stimulus regulated the G1 cyclin-cyclin dependent kinase (CDK)-inhibitor system, and to determine the roles of PI 3-kinase activation by cAMP or IGF-I stimulus in this system. We found that cAMP pretreatment enhanced IGF-I-dependent increases in cyclin D1, due to synergistic increases in mRNA and elevation of translation rates. Furthermore, cAMP pretreatment enhanced IGF-I-induced protein degradation of the CDK inhibitor, p27(Kip1). These changes well explained an increase in cyclin E, leading to marked activation of G1 CDKs, followed by retinoblastoma protein phosphorylation. Our results using a PI 3-kinase inhibitor showed that cAMP-dependent PI 3-kinase activation plays an important role in the increase in cyclin D1 translation. In contrast, IGF-I-dependent PI 3-kinase activation was required for the increase in cyclin D1 mRNA levels and degradation of p27(Kip1). Together, the present study elucidates the role of cAMP and IGF-I in differentially activating PI 3-kinase as a mediator of multiple molecular events. These events converge in the regulation of cyclin D1 and p27(Kip1), leading to cAMP-dependent potentiation of IGF-I-dependent CDK activation and DNA synthesis.
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Affiliation(s)
- Toshiaki Fukushima
- Laboratory of Cell Regulation, Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
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Lewiński A, Marcinkowska M, Brzeziańska E, Jeziorowska A, Włoch J, Brzeziński J. Expression of insulin-like growth factor I (IGF-I) gene and of genes for IGF-binding proteins 1, 2, 3, 4 (IGFBP-1-IGFBP-4) in non-neoplastic human thyroid cells and in certain human thyroid cancers. Effect of exogenous IGF-I on this expression. Endocr Res 2004; 30:47-59. [PMID: 15098919 DOI: 10.1081/erc-120028484] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
AIM The aim of this study was to examine the expression of the IGF-I gene and of genes for IGFBP-1, -2, -3, and -4 in cells from nodular goiters (NG), and from different human thyroid carcinomas (papillary--PTC, anaplastic--ATC, and medullary--MTC), cultured in monolayers. The influence, exerted by exogenous IGF-I on the expression of these genes, was also investigated. METHODS Thyroid tissue specimens were obtained from 65 patients during subtotal or total thyroidectomies. After approximately 2-3 weeks of culture, thyroid cells were incubated for 24 hours with IGF-I in concentrations of: 0, 1, 10 and 100 ng/ml. The total mRNA was isolated according to the method described by Chomczyński and Sacchi with our own modifications. Afterwards, mRNA encoding IGF-I, IGFBP-1-IGFBP-4 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), were amplified, using the reverse transcription-polymerase chain reaction (RT-PCR); GAPDH gene served as a control gene. PCR products were electrophoresed and then submitted to densitometric analysis. RESULTS AND CONCLUSIONS Our study has shown that in carcinoma cells (ATC, PTC, MTC), IGF-I reveals a stimulatory influence on the expression of its own gene, that effect being most distinctive in ATC cells. These facts indicate an important role of IGF-I in the pathogenesis and invasiveness of the analyzed malignant neoplasms.
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Affiliation(s)
- Andrzej Lewiński
- Department of Thyroidology, Institute of Endocrinology, Medical University of Lodź, Lodź, Poland.
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Clément S, Refetoff S, Robaye B, Dumont JE, Schurmans S. Low TSH requirement and goiter in transgenic mice overexpressing IGF-I and IGF-Ir receptor in the thyroid gland. Endocrinology 2001; 142:5131-9. [PMID: 11713206 DOI: 10.1210/endo.142.12.8534] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Through the cAMP signaling pathway, TSH stimulates thyroid follicular cell proliferation, differentiation, and function. Although the autocrine production of IGF-I in the thyroid gland suggests an important physiological function for this factor in these processes, the exact role of the IGF-I/IGF-I receptor system in vivo remains unclear. Although the mitogenic action of TSH requires the presence of IGF-I or insulin in primary culture of dog and human thyroid cells, IGF-I has an effect equal to and independent of the effect of TSH on cell proliferation in rat thyroid cell lines and may even be the main growth regulator in this case. To investigate the in vivo function of the IGF-I/IGF-I receptor system, transgenic mice overexpressing human IGF-I, IGF-I receptor, or both in the thyroid were generated. Adult transgenic mice did not present external signs of thyroid dysfunction, but mice overexpressing both transgenes had significantly increased gland weight and follicular lumen area. A decreased TSH level together with a slightly increased serum T(4) concentration and increased thyroidal iodine uptake were also observed, suggesting that IGF-I and IGF-I receptor stimulate thyroid function to some extent in vivo.
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Affiliation(s)
- S Clément
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Nucléaire, Institut de Biologie et de Médecine Moléculaire, Université Libre de Bruxelles, 6041 Gosselies, Belgium.
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Kimura T, Van Keymeulen A, Golstein J, Fusco A, Dumont JE, Roger PP. Regulation of thyroid cell proliferation by TSH and other factors: a critical evaluation of in vitro models. Endocr Rev 2001; 22:631-56. [PMID: 11588145 DOI: 10.1210/edrv.22.5.0444] [Citation(s) in RCA: 297] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
TSH via cAMP, and various growth factors, in cooperation with insulin or IGF-I stimulate cell cycle progression and proliferation in various thyrocyte culture systems, including rat thyroid cell lines (FRTL-5, WRT, PC Cl3) and primary cultures of rat, dog, sheep and human thyroid. The available data on cell signaling cascades, cell cycle kinetics, and cell cycle-regulatory proteins are thoroughly and critically reviewed in these experimental systems. In most FRTL-5 cells, TSH (cAMP) merely acts as a priming/competence factor amplifying PI3K and MAPK pathway activation and DNA synthesis elicited by insulin/IGF-I. In WRT cells, TSH and insulin/IGF-I can independently activate Ras and PI3K pathways and DNA synthesis. In dog thyroid primary cultures, TSH (cAMP) does not activate Ras and PI3K, and cAMP must be continuously elevated by TSH to directly control the progression through G(1) phase. This effect is exerted, at least in part, via the cAMP-dependent activation of the required cyclin D3, itself synthesized in response to insulin/IGF-I. This and other discrepancies show that the mechanistic logics of cell cycle stimulation by cAMP profoundly diverge in these different in vitro models of the same cell. Therefore, although these different thyrocyte systems constitute interesting models of the wide diversity of possible mechanisms of cAMP-dependent proliferation in various cell types, extrapolation of in vitro mechanistic data to TSH-dependent goitrogenesis in man can only be accepted in the cases where independent validation is provided.
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Affiliation(s)
- T Kimura
- Institute of Interdisciplinary Research (IRIBHN), School of Medicine, Université Libre de Bruxelles, Campus Erasme, B-1070 Brussels, Belgium
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Van Keymeulen A, Dumont JE, Roger PP. TSH induces insulin receptors that mediate insulin costimulation of growth in normal human thyroid cells. Biochem Biophys Res Commun 2000; 279:202-7. [PMID: 11112439 DOI: 10.1006/bbrc.2000.3910] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mitogenic/goitrogenic effects of thyrotropin (TSH) on human thyrocytes in vitro and in vivo depend on permissive comitogenic effects of insulin-like growth factors (IGFs), which are mimicked in vitro by the low-affinity binding of high supraphysiological concentrations of insulin to IGF-I receptors. Contrary to general assumption, we show here that very low concentrations of insulin, acting through insulin receptors but not IGF-I receptors, can also support the stimulation of DNA synthesis by TSH in primary cultures of normal human thyrocytes. Moreover, TSH through cAMP increases the content of insulin receptors demonstrated by Western blotting and the cells' responsiveness to low insulin concentrations. These observations provide the first in vitro evidence in normal human thyroid cells of a functional interaction between TSH and insulin acting through its own receptor.
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Affiliation(s)
- A Van Keymeulen
- Institute of Interdisciplinary Research (IRIBHN), School of Medicine, Université Libre de Bruxelles, B-1070 Brussels, Belgium
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Van Keymeulen A, Bartek J, Dumont JE, Roger PP. Cyclin D3 accumulation and activity integrate and rank the comitogenic pathways of thyrotropin and insulin in thyrocytes in primary culture. Oncogene 1999; 18:7351-9. [PMID: 10602491 DOI: 10.1038/sj.onc.1203164] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The proliferation of most normal cells depends on the synergistic interaction of several growth factors and hormones, but the cell cycle basis for this combined requirement remains largely uncharacterized. We have addressed the question of the requirement for insulin/IGF-1 also observed in many cell culture systems in the physiologically relevant system of primary cultures of dog thyroid epithelial cells stimulated by TSH, which exerts its mitogenic activity only via cAMP. The induction of cyclin A and cdc2, the phosphorylation of cdk2, the nuclear translocation of cdk4 and the assembly of cyclin D3-cdk4 complexes required the synergy of TSH and insulin. Cyclin D3 (the most abundant cyclin D) was necessary for the proliferation stimulated by TSH in the presence of insulin as shown by microinjection of a neutralizing antibody. Cyclin D3 accumulation and activity were differentially regulated by insulin and TSH, which points out this cyclin as an integrator that ranks these comitogenic pathways as supportive and activatory, respectively. Paradoxically TSH alone strongly repressed cyclin D3 accumulation. This inhibition was overridden by insulin, which markedly stimulated cyclin D3 mRNA and protein accumulation, but failed to assemble cyclin D3-cdk4 complexes in the absence of TSH. TSH unmasked the DCS-22 epitope of cyclin D3 and assembled cyclin D3-cdk4 in the presence of insulin. These data demonstrate that cyclin D synthesis and cyclin D-cdk assembly can be dissociated and complementarily regulated by different agents and signalling pathways.
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Affiliation(s)
- A Van Keymeulen
- Institute of Interdisciplinary Research, Université Libre de Bruxelles, Campus Erasme, 808 Route de Lennik, B-1070 Brussels, Belgium
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Denef C. Autocrine/Paracrine Intermediates in Hormonal Action and Modulation of Cellular Responses to Hormones. Compr Physiol 1998. [DOI: 10.1002/cphy.cp070118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Burikhanov R, Coulonval K, Pirson I, Lamy F, Dumont JE, Roger PP. Thyrotropin via cyclic AMP induces insulin receptor expression and insulin Co-stimulation of growth and amplifies insulin and insulin-like growth factor signaling pathways in dog thyroid epithelial cells. J Biol Chem 1996; 271:29400-6. [PMID: 8910605 DOI: 10.1074/jbc.271.46.29400] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Despite the similarity of their receptors and signal transduction pathways, insulin is regarded as a regulator of glucose, protein, and lipid metabolism, whereas insulin-like growth factors (IGF-I and IGF-II) mainly act as mitogenic hormones. In the dog thyroid primary culture model, the triggering of DNA synthesis by thyrotropin (TSH) through cAMP, or by cAMP-independent factors including epidermal growth factor, hepatocyte growth factor and phorbol esters, requires insulin or IGFs as comitogenic factors. In the present study, in TSH-treated cells, IGF-I receptors and insulin receptors were paradoxically equivalent in their capacity to elicit the comitogenic pathway, which, however, was mediated only by IGF-I receptors in dog thyroid cells stimulated by cAMP-independent mitogens. Moreover, prior cell exposure to TSH or forskolin increased their responsiveness to insulin, IGF-I, and IGF-II, as seen on DNA synthesis and activation of a common insulin/IGF signaling pathway. To understand these observations, binding characteristics and expression of insulin and IGF-I receptors were examined. To analyze IGF-I receptor characteristics, the unexpected interference of a huge presence of IGF-binding proteins at the cell membrane was avoided using labeled Long R3 IGF-I instead of IGF-I. Strikingly, TSH, through cAMP, time-dependently induced insulin binding and insulin receptor mRNA and protein accumulation without any effect on IGF-I receptors. These findings constitute a first example of an induction of insulin receptor gene expression by a cAMP-mediated hormone. In dog thyroid cells, this allows low physiological insulin concentrations to act as a comitogenic factor and might explain in part the enhanced responsiveness to IGFs in response to TSH. This raises the possibility that TSH-insulin interactions may play a role in the regulation of thyroid growth and function in vivo.
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Affiliation(s)
- R Burikhanov
- Institute of Interdisciplinary Research, Université Libre de Bruxelles, Campus Erasme, 1070 Brussels, Belgium
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Takahashi MH, Thomas GA, Williams ED. Evidence for mutual interdependence of epithelium and stromal lymphoid cells in a subset of papillary carcinomas. Br J Cancer 1995; 72:813-7. [PMID: 7547225 PMCID: PMC2034040 DOI: 10.1038/bjc.1995.418] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We have correlated the morphological features of 30 human thyroid carcinomas with the cellular localisation of insulin-like growth factor 1 (IGF-1) mRNA and IGF-1 receptor peptide using in situ hybridisation with digoxigenin-labelled oligoprobes and immunohistochemistry. Four of the five follicular carcinomas studied showed a consistent, uniform, strong positivity for IGF-1 mRNA in tumour cells compared with weakly positive surrounding normal follicular tissue and negative stroma. The majority of papillary carcinomas showed weak to moderate epithelial positivity for IGF-1 mRNA and negative stroma. Immunohistochemistry for IGF-1 receptor showed moderate positivity confined to the tumour epithelial cells in both follicular and the majority of papillary carcinomas. However, in a subgroup of papillary carcinomas characterised by a diffuse stromal lymphoid infiltration (n = 5), the stromal cells showed a much stronger reactivity for IGF-1 mRNA than the tumour or background thyroid, and the tumour cells showed a uniformly high level of immunoreactivity for IGF-1 receptor. These results are compatible with the growth of the papillary carcinoma in these cases being the result of a symbiotic relationship between the stromal lymphoid cells and the tumour epithelium with the lymphoid cells responding to an antigen produced by the tumour cells and the tumour cells responding to a growth factor produced by the lymphoid infiltrate. We suggest that this mechanism may be important in other tumours regularly associated with a widespread lymphoid infiltrate.
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Affiliation(s)
- M H Takahashi
- Department of Histopathology, University of Cambridge, Addenbrooke's Hospital, UK
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