1
|
Aksoy O, Hantusch B, Kenner L. Emerging role of T3-binding protein μ-crystallin (CRYM) in health and disease. Trends Endocrinol Metab 2022; 33:804-816. [PMID: 36344381 DOI: 10.1016/j.tem.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Thyroid hormones are essential metabolic and developmental regulators that exert a huge variety of effects in different organs. Triiodothyronine (T3) and thyroxine (T4) are synthesized in the thyroid gland and constitute unique iodine-containing hormones that are constantly regulated by a homeostatic feedback mechanism. T3/T4 activity in cells is mainly determined by specific transporters, cytosolic binding proteins, deiodinases (DIOs), and nuclear receptors. Modulation of intracellular T3/T4 level contributes to the maintenance of this regulatory feedback. μ-Crystallin (CRYM) is an important intracellular high-affinity T3-binding protein that buffers the amount of T3 freely available in the cytosol, thereby controlling its action. In this review, we focus on the molecular and pathological properties of CRYM in thyroid hormone signaling, with emphasis on its critical role in malignancies.
Collapse
Affiliation(s)
- Osman Aksoy
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Brigitte Hantusch
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Lukas Kenner
- Department of Pathology, Medical University of Vienna, Vienna, Austria; Center for Biomarker Research in Medicine (CBmed), Graz, Austria; Unit for Laboratory Animal Pathology, University of Veterinary Medicine Vienna, Vienna, Austria; Christian Doppler Laboratory for Applied Metabolomics (CDL-AM), Medical University of Vienna, Vienna, Austria.
| |
Collapse
|
2
|
Fischer J, Kleinau G, Müller A, Kühnen P, Zwanziger D, Kinne A, Rehders M, Moeller LC, Führer D, Grüters A, Krude H, Brix K, Biebermann H. Modulation of monocarboxylate transporter 8 oligomerization by specific pathogenic mutations. J Mol Endocrinol 2015; 54:39-50. [PMID: 25527620 DOI: 10.1530/jme-14-0272] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The monocarboxylate transporter 8 (MCT8) is a member of the major facilitator superfamily (MFS). These membrane-spanning proteins facilitate translocation of a variety of substrates, MCT8 specifically transports iodothyronines. Mutations in MCT8 are the underlying cause of severe X-linked psychomotor retardation. At the molecular level, such mutations led to deficiencies in substrate translocation due to reduced cell-surface expression, impaired substrate binding, or decreased substrate translocation capabilities. However, the causal relationships between genotypes, molecular features of mutated MCT8, and patient characteristics have not yet been comprehensively deciphered. We investigated the relationship between pathogenic mutants of MCT8 and their capacity to form dimers (presumably oligomeric structures) as a potential regulatory parameter of the transport function of MCT8. Fourteen pathogenic variants of MCT8 were investigated in vitro with respect to their capacity to form oligomers. Particular mutations close to the substrate translocation channel (S194F, A224T, L434W, and R445C) were found to inhibit dimerization of MCT8. This finding is in contrast to those for other transporters or transmembrane proteins, in which substitutions predominantly at the outer-surface inhibit oligomerization. Moreover, specific mutations of MCT8 located in transmembrane helix 2 (del230F, V235M, and ins236V) increased the capacity of MCT8 variants to dimerize. We analyzed the localization of MCT8 dimers in a cellular context, demonstrating differences in MCT8 dimer formation and distribution. In summary, our results add a new link between the functions (substrate transport) and protein organization (dimerization) of MCT8, and might be of relevance for other members of the MFS. Finally, the findings are discussed in relationship to functional data combined with structural-mechanistical insights into MCT8.
Collapse
Affiliation(s)
- Jana Fischer
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Gunnar Kleinau
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Anne Müller
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Peter Kühnen
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Denise Zwanziger
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Anita Kinne
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Maren Rehders
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Lars C Moeller
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Dagmar Führer
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Annette Grüters
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Heiko Krude
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Klaudia Brix
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Heike Biebermann
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| |
Collapse
|
3
|
Read ML, Seed RI, Modasia B, Kwan PPK, Sharma N, Smith VE, Watkins RJ, Bansal S, Gagliano T, Stratford AL, Ismail T, Wakelam MJO, Kim DS, Ward ST, Boelaert K, Franklyn JA, Turnell AS, McCabe CJ. The proto-oncogene PBF binds p53 and is associated with prognostic features in colorectal cancer. Mol Carcinog 2014; 55:15-26. [PMID: 25408419 DOI: 10.1002/mc.22254] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/08/2014] [Accepted: 10/22/2014] [Indexed: 12/20/2022]
Abstract
The PTTG1-binding factor (PBF) is a transforming gene capable of eliciting tumor formation in xenograft models. However, the precise role of PBF in tumorigenesis and its prognostic value as a cancer biomarker remain largely uncharacterised, particularly in malignancies outside the thyroid. Here, we provide the first evidence that PBF represents a promising prognostic marker in colorectal cancer. Examination of a total of 39 patients demonstrated higher PBF expression at both the mRNA (P = 0.009) and protein (P < 0.0001) level in colorectal tumors compared to matched normal tissue. Critically, PBF was most abundant in colorectal tumors associated with Extramural Vascular Invasion (EMVI), increased genetic instability (GI) and somatic TP53 mutations, all features linked with recurrence and poorer patient survival. We further demonstrate by glutathione-S-transferase (GST) pull-down and coimmunoprecipitation that PBF binds to the tumor suppressor protein p53, as well as to p53 mutants (Δ126-132, M133K, V197E, G245D, I255F and R273C) identified in the colorectal tumors. Importantly, overexpression of PBF in colorectal HCT116 cells interfered with the transcriptional activity of p53-responsive genes such as mdm2, p21 and sfn. Diminished p53 stability (> 90%; P < 0.01) was also evident with a concurrent increase in ubiquitinated p53. Human colorectal tumors with wild-type TP53 and high PBF expression also had low p53 protein levels (P < 0.05), further emphasizing a putative interaction between these genes in vivo. Overall, these results demonstrate an emerging role for PBF in colorectal tumorigenesis through regulating p53 activity, with implications for PBF as a prognostic indicator for invasive tumors.
Collapse
Affiliation(s)
- Martin L Read
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Robert I Seed
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Bhavika Modasia
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Perkin P K Kwan
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Neil Sharma
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Vicki E Smith
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Rachel J Watkins
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Sukhchain Bansal
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | | | - Anna L Stratford
- Department of Pediatrics, University of British Columbia, Canada
| | - Tariq Ismail
- School of Cancer Sciences, University of Birmingham, UK
| | | | - Dae S Kim
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Stephen T Ward
- Centre for Liver Research and NIHR Centre for Biomedical Research Unit, University of Birmingham, UK
| | - Kristien Boelaert
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Jayne A Franklyn
- School of Clinical and Experimental Medicine, University of Birmingham, UK
| | | | | |
Collapse
|
4
|
Colicchia M, Campagnolo L, Baldini E, Ulisse S, Valensise H, Moretti C. Molecular basis of thyrotropin and thyroid hormone action during implantation and early development. Hum Reprod Update 2014; 20:884-904. [PMID: 24943836 DOI: 10.1093/humupd/dmu028] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Implantation and early embryo development are finely regulated processes in which several molecules are involved. Evidence that thyroid hormones (TH: T4 and T3) might be part of this machinery is emerging. An increased demand for TH occurs during gestation, and any alteration in maternal thyroid physiology has significant implications for both maternal and fetal health. Not only overt but also subclinical hypothyroidism is associated with infertility as well as with obstetric complications, including disruptions and disorders of pregnancy, labor, delivery, and troubles in early neonatal life. METHODS We searched the PubMed and Google Scholar databases for articles related to TH action on ovary, endometrium, trophoblast maturation and embryo implantation. In addition, articles on the regulation of TH activity at cellular level have been reviewed. The findings are hereby summarized and critically discussed. RESULTS TH have been shown to influence endometrial, ovarian and placental physiology. TH receptors (TR) and thyrotropin (thyroid-stimulating hormone: TSH) receptors (TSHR) are widely expressed in the feto-maternal unit during implantation, and both the endometrium and the trophoblast might be influenced by TH either directly or through TH effects on the synthesis and activity of implantation-mediating molecules. Interestingly, due to the multiplicity of mechanisms involved in TH action (e.g. differential expression of TR isoforms, heterodimeric receptor partners, interacting cellular proteins, and regulating enzymes), the TH concentration in blood is not always predictive of their cellular availability and activity at both genomic and nongenomic level. CONCLUSIONS In addition to the known role of TH on the hormonal milieu of the ovarian follicle cycle, which is essential for a woman's fertility, evidence is emerging on the importance of TH signaling during implantation and early pregnancy. Based on recent observations, a local action of TH on female reproductive organs and the embryo during implantation appears to be crucial for a successful pregnancy. Furthermore, an imbalance in the spatio-temporal expression of factors involved in TH activity might induce early arrest of pregnancy in women considered as euthyroid, based on their hormonal blood concentration. In conclusion, alterations of the highly regulated local activity of TH may play a crucial, previously underestimated, role in early pregnancy and pregnancy loss. Further studies elucidating this topic should be encouraged.
Collapse
Affiliation(s)
- Martina Colicchia
- Department of Systems' Medicine, University of Rome Tor Vergata, UOC of Endocrinology and Diabetes, Section of Reproductive Endocrinology Fatebenefratelli Hospital, 'Isola Tiberina' 00187, Rome, Italy
| | - Luisa Campagnolo
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier1, 00133 Rome, Italy
| | - Enke Baldini
- Department of Experimental Medicine, 'Sapienza' University of Rome, Rome, Italy
| | - Salvatore Ulisse
- Department of Experimental Medicine, 'Sapienza' University of Rome, Rome, Italy
| | - Herbert Valensise
- Department of Obstetrics and Gynaecology, University of Rome Tor Vergata, Fatebenefratelli Hospital 'Isola Tiberina', 00187 Rome, Italy
| | - Costanzo Moretti
- Department of Systems' Medicine, University of Rome Tor Vergata, UOC of Endocrinology and Diabetes, Section of Reproductive Endocrinology Fatebenefratelli Hospital, 'Isola Tiberina' 00187, Rome, Italy
| |
Collapse
|
5
|
Chan SY, Hancox LA, Martín-Santos A, Loubière LS, Walter MNM, González AM, Cox PM, Logan A, McCabe CJ, Franklyn JA, Kilby MD. MCT8 expression in human fetal cerebral cortex is reduced in severe intrauterine growth restriction. J Endocrinol 2014; 220:85-95. [PMID: 24204008 PMCID: PMC3921694 DOI: 10.1530/joe-13-0400] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The importance of the thyroid hormone (TH) transporter, monocarboxylate transporter 8 (MCT8), to human neurodevelopment is highlighted by findings of severe global neurological impairment in subjects with MCT8 (SLC16A2) mutations. Intrauterine growth restriction (IUGR), usually due to uteroplacental failure, is associated with milder neurodevelopmental deficits, which have been partly attributed to dysregulated TH action in utero secondary to reduced circulating fetal TH concentrations and decreased cerebral thyroid hormone receptor expression. We postulate that altered MCT8 expression is implicated in this pathophysiology; therefore, in this study, we sought to quantify changes in cortical MCT8 expression with IUGR. First, MCT8 immunohistochemistry was performed on occipital and parietal cerebral cortex sections obtained from appropriately grown for gestational age (AGA) human fetuses between 19 weeks of gestation and term. Secondly, MCT8 immunostaining in the occipital cortex of stillborn IUGR human fetuses at 24-28 weeks of gestation was objectively compared with that in the occipital cortex of gestationally matched AGA fetuses. Fetuses demonstrated widespread MCT8 expression in neurons within the cortical plate and subplate, in the ventricular and subventricular zones, in the epithelium of the choroid plexus and ependyma, and in microvessel wall. When complicated by IUGR, fetuses showed a significant fivefold reduction in the percentage area of cortical plate immunostained for MCT8 compared with AGA fetuses (P<0.05), but there was no significant difference in the proportion of subplate microvessels immunostained. Cortical MCT8 expression was negatively correlated with the severity of IUGR indicated by the brain:liver weight ratios (r(2)=0.28; P<0.05) at post-mortem. Our results support the hypothesis that a reduction in MCT8 expression in the IUGR fetal brain could further compromise TH-dependent brain development.
Collapse
Affiliation(s)
- Shiao Y Chan
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
- Correspondence should be addressed to S Y Chan;
| | - Laura A Hancox
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Azucena Martín-Santos
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Laurence S Loubière
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Merlin N M Walter
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Ana-Maria González
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Phillip M Cox
- Department of PathologyBirmingham Women's NHS Foundation TrustEdgbaston, Birmingham, B15 2TGUK
| | - Ann Logan
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Christopher J McCabe
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Jayne A Franklyn
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
| | - Mark D Kilby
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamEdgbaston, Birmingham, B15 2TTUK
- Fetal Medicine Centre, Birmingham Women's NHS Foundation TrustEdgbaston, Birmingham, B15 2TGUK
| |
Collapse
|
6
|
Rodrigues TB, Ceballos A, Grijota-Martínez C, Nuñez B, Refetoff S, Cerdán S, Morte B, Bernal J. Increased oxidative metabolism and neurotransmitter cycling in the brain of mice lacking the thyroid hormone transporter SLC16A2 (MCT8). PLoS One 2013; 8:e74621. [PMID: 24098341 PMCID: PMC3788064 DOI: 10.1371/journal.pone.0074621] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 08/03/2013] [Indexed: 11/19/2022] Open
Abstract
Mutations of the monocarboxylate transporter 8 (MCT8) cause a severe X-linked intellectual deficit and neurological impairment. MCT8 is a specific thyroid hormone (T4 and T3) transporter and the patients also present unusual abnormalities in the serum profile of thyroid hormone concentrations due to altered secretion and metabolism of T4 and T3. Given the role of thyroid hormones in brain development, it is thought that the neurological impairment is due to restricted transport of thyroid hormones to the target neurons. In this work we have investigated cerebral metabolism in mice with Mct8 deficiency. Adult male mice were infused for 30 minutes with (1-(13)C) glucose and brain extracts prepared and analyzed by (13)C nuclear magnetic resonance spectroscopy. Genetic inactivation of Mct8 resulted in increased oxidative metabolism as reflected by increased glutamate C4 enrichment, and of glutamatergic and GABAergic neurotransmissions as observed by the increases in glutamine C4 and GABA C2 enrichments, respectively. These changes were distinct to those produced by hypothyroidism or hyperthyroidism. Similar increments in glutamate C4 enrichment and GABAergic neurotransmission were observed in the combined inactivation of Mct8 and D2, indicating that the increased neurotransmission and metabolic activity were not due to increased production of cerebral T3 by the D2-encoded type 2 deiodinase. In conclusion, Mct8 deficiency has important metabolic consequences in the brain that could not be correlated with deficiency or excess of thyroid hormone supply to the brain during adulthood.
Collapse
Affiliation(s)
- Tiago B. Rodrigues
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
- CRUK, Cambridge Institute and Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Ainhoa Ceballos
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
| | - Carmen Grijota-Martínez
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
- Center for Biomedical Research on Rare Diseases, Madrid, Spain
| | - Barbara Nuñez
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
| | - Samuel Refetoff
- Departments of Medicine, Pediatrics and Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Sebastian Cerdán
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
| | - Beatriz Morte
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
- Center for Biomedical Research on Rare Diseases, Madrid, Spain
| | - Juan Bernal
- Instituto de Investigaciones Biomedicas, Consejo Superior de Investigaciones Cientificas and Universidad Autonoma de Madrid, Madrid, Spain
- Center for Biomedical Research on Rare Diseases, Madrid, Spain
| |
Collapse
|
7
|
Vasilopoulou E, Loubière LS, Heuer H, Trajkovic-Arsic M, Darras VM, Visser TJ, Lash GE, Whitley GS, McCabe CJ, Franklyn JA, Kilby MD, Chan SY. Monocarboxylate transporter 8 modulates the viability and invasive capacity of human placental cells and fetoplacental growth in mice. PLoS One 2013; 8:e65402. [PMID: 23776477 PMCID: PMC3680392 DOI: 10.1371/journal.pone.0065402] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 04/25/2013] [Indexed: 11/22/2022] Open
Abstract
Monocarboxylate transporter 8 (MCT8) is a well-established thyroid hormone (TH) transporter. In humans, MCT8 mutations result in changes in circulating TH concentrations and X-linked severe global neurodevelopmental delay. MCT8 is expressed in the human placenta throughout gestation, with increased expression in trophoblast cells from growth-restricted pregnancies. We postulate that MCT8 plays an important role in placental development and transplacental TH transport. We investigated the effect of altering MCT8 expression in human trophoblast in vitro and in a Mct8 knockout mouse model. Silencing of endogenous MCT8 reduced T3 uptake into human extravillous trophoblast-like cells (SGHPL-4; 40%, P<0.05) and primary cytotrophoblast (15%, P<0.05). MCT8 over-expression transiently increased T3 uptake (SGHPL-4∶30%, P<0.05; cytotrophoblast: 15%, P<0.05). Silencing MCT8 did not significantly affect SGHPL-4 invasion, but with MCT8 over-expression T3 treatment promoted invasion compared with no T3 (3.3-fold; P<0.05). Furthermore, MCT8 silencing increased cytotrophoblast viability (∼20%, P<0.05) and MCT8 over-expression reduced cytotrophoblast viability independently of T3 (∼20%, P<0.05). In vivo, Mct8 knockout reduced fetal:placental weight ratios compared with wild-type controls at gestational day 18 (25%, P<0.05) but absolute fetal and placental weights were not significantly different. The volume fraction of the labyrinthine zone of the placenta, which facilitates maternal-fetal exchange, was reduced in Mct8 knockout placentae (10%, P<0.05). However, there was no effect on mouse placental cell proliferation in vivo. We conclude that MCT8 makes a significant contribution to T3 uptake into human trophoblast cells and has a role in modulating human trophoblast cell invasion and viability. In mice, Mct8 knockout has subtle effects upon fetoplacental growth and does not significantly affect placental cell viability probably due to compensatory mechanisms in vivo.
Collapse
Affiliation(s)
- Elisavet Vasilopoulou
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Laurence S. Loubière
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Heike Heuer
- Leibniz Institute for Age Research/Fritz Lipmann Institute, Jena, Germany
| | | | - Veerle M. Darras
- Laboratory of Comparative Endocrinology, Katholieke Universiteit, Leuven, Belgium
| | | | - Gendie E. Lash
- Reproductive and Vascular Biology Group, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Guy S. Whitley
- Division of Biomedical Sciences, St George’s University of London, London, United Kingdom
| | - Christopher J. McCabe
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Jayne A. Franklyn
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Mark D. Kilby
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Shiao Y. Chan
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- * E-mail:
| |
Collapse
|
8
|
Schweizer U, Köhrle J. Function of thyroid hormone transporters in the central nervous system. Biochim Biophys Acta Gen Subj 2012; 1830:3965-73. [PMID: 22890106 DOI: 10.1016/j.bbagen.2012.07.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/12/2012] [Accepted: 07/30/2012] [Indexed: 01/24/2023]
Abstract
BACKGROUND Iodothyronines are charged amino acid derivatives that cannot passively cross a phospholipid bilayer. Transport of thyroid hormones across plasma membranes is mediated by integral membrane proteins belonging to several gene families. These transporters therefore allow or limit access of thyroid hormones into brain. Since thyroid hormones are essential for brain development and cell differentiation, it is expected that genetic deficiency of such transporters would result in neurodevelopmental derangements. SCOPE OF REVIEW We introduce concepts of thyroid hormone transport into the brain and into brain cells. Important thyroid hormone transmembrane transporters are presented along with their expression patterns in different brain cell types. A focus is placed on monocarboxylate transporter 8 (MCT8) which has been identified as an essential thyroid hormone transporter in humans. Mutations in MCT8 underlie one of the first described X-linked mental retardation syndromes, the Allan-Herndon-Dudley syndrome. MAJOR CONCLUSIONS Thyroid hormone transporter molecules are expressed in a developmental and cell type-specific pattern. Any thyroid hormone molecule has to cross consecutively the luminal and abluminal membranes of the capillary endothelium, enter astrocytic foot processes, and leave the astrocyte through the plasma membrane to finally cross another plasma membrane on its way towards its target nucleus. GENERAL SIGNIFICANCE We can expect more transporters being involved in or contributing to in neurodevelopmental or neuropsychiatric disease. Due to their expression in cellular components regulating the hypothalamus-pituitary-thyroid axis, mutations and polymorphisms are expected to impact on negative feedback regulation and hormonal setpoints. This article is part of a Special Issue entitled Thyroid hormone signalling.
Collapse
Affiliation(s)
- Ulrich Schweizer
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
| | | |
Collapse
|
9
|
Smith VE, Read ML, Turnell AS, Sharma N, Lewy GD, Fong JCW, Seed RI, Kwan P, Ryan G, Mehanna H, Chan SY, Darras VM, Boelaert K, Franklyn JA, McCabe CJ. PTTG-binding factor (PBF) is a novel regulator of the thyroid hormone transporter MCT8. Endocrinology 2012; 153:3526-36. [PMID: 22535767 DOI: 10.1210/en.2011-2030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Within the basolateral membrane of thyroid follicular epithelial cells, two transporter proteins are central to thyroid hormone (TH) biosynthesis and secretion. The sodium iodide symporter (NIS) delivers iodide from the bloodstream into the thyroid, and after TH biosynthesis, monocarboxylate transporter 8 (MCT8) mediates TH secretion from the thyroid gland. Pituitary tumor-transforming gene-binding factor (PBF; PTTG1IP) is a protooncogene that is up-regulated in thyroid cancer and that binds NIS and modulates its subcellular localization and function. We now show that PBF binds MCT8 in vitro, eliciting a marked shift in MCT8 subcellular localization and resulting in a significant reduction in the amount of MCT8 at the plasma membrane as determined by cell surface biotinylation assays. Colocalization and interaction between PBF and Mct8 was also observed in vivo in a mouse model of thyroid-specific PBF overexpression driven by a bovine thyroglobulin (Tg) promoter (PBF-Tg). Thyroidal Mct8 mRNA and protein expression levels were similar to wild-type mice. Critically, however, PBF-Tg mice demonstrated significantly enhanced thyroidal TH accumulation and reduced TH secretion upon TSH stimulation. Importantly, Mct8-knockout mice share this phenotype. These data show that PBF binds and alters the subcellular localization of MCT8 in vitro, with PBF overexpression leading to an accumulation of TH within the thyroid in vivo. Overall, these studies identify PBF as the first protein to interact with the critical TH transporter MCT8 and modulate its function in vivo. Furthermore, alongside NIS repression, PBF may thus represent a new regulator of TH biosynthesis and secretion.
Collapse
Affiliation(s)
- V E Smith
- School of Clinical and Experimental Medicine, Institute for Biomedical Research, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Chan SY, Martín-Santos A, Loubière LS, González AM, Stieger B, Logan A, McCabe CJ, Franklyn JA, Kilby MD. The expression of thyroid hormone transporters in the human fetal cerebral cortex during early development and in N-Tera-2 neurodifferentiation. J Physiol 2011; 589:2827-45. [PMID: 21486766 DOI: 10.1113/jphysiol.2011.207290] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Associations of neurological impairment with mutations in the thyroid hormone (TH) transporter, MCT8, and with maternal hypothyroxinaemia, suggest that THs are crucial for human fetal brain development. It has been postulated that TH transporters regulate the cellular supply of THs within the fetal brain during development. This study describes the expression of TH transporters in the human fetal cerebral cortex (7–20 weeks gestation) and during retinoic acid induced neurodifferentiation of the human N-Tera-2 (NT2) cell line, in triiodothyronine (T3) replete and T3-depleted media. Compared with adult cortex, mRNAs encoding OATP1A2, OATP1C1, OATP3A1 variant 2, OATP4A1, LAT2 and CD98 were reduced in fetal cortex at different gestational ages, whilst mRNAs encoding MCT8, MCT10, OATP3A1 variant 1 and LAT1 were similar. From the early first trimester, immunohistochemistry localised MCT8 and MCT10 to the microvasculature and to undifferentiated CNS cells. With neurodifferentiation, NT2 cells demonstrated declining T3 uptake, accompanied by reduced expressions of MCT8, LAT1, CD98 and OATP4A1. T3 depletion significantly reduced MCT10 and LAT2 mRNA expression at specific time points during neurodifferentiation but there were no effects upon T3 uptake, neurodifferentiation marker expression or neurite lengths and branching. MCT8 repression also did not affect NT2 neurodifferentiation. In conclusion, many TH transporters are expressed in the human fetal cerebral cortex from the first trimester, which could regulate cellular TH supply during early development. However, human NT2 neurodifferentiation is not dependent upon T3 or MCT8 and there were no compensatory changes to promote T3 uptake in a T3-depleted environment.
Collapse
Affiliation(s)
- S-Y Chan
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Floor 3, Birmingham Women's Hospital, Edgbaston, Birmingham B15 2TG, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Vasilopoulou E, Loubière LS, Martín-Santos A, McCabe CJ, Franklyn JA, Kilby MD, Chan SY. Differential triiodothyronine responsiveness and transport by human cytotrophoblasts from normal and growth-restricted pregnancies. J Clin Endocrinol Metab 2010; 95:4762-70. [PMID: 20660035 PMCID: PMC3050105 DOI: 10.1210/jc.2010-0354] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CONTEXT Abnormal placentation in human pregnancy is associated with intrauterine fetal growth restriction (IUGR). Our group has previously reported the association between severe IUGR, lower fetal circulating concentrations of thyroid hormones (THs), and altered expression of TH receptors and TH transporters within human placental villi. We postulate that altered TH bioavailability to trophoblasts may contribute to the pathogenesis of IUGR. DESIGN AND OBJECTIVE Cytotrophoblasts were isolated from normal and IUGR human placentae to compare their responsiveness to T(3) and their capability for T(3) transport. RESULTS Compared with normal cytotrophoblasts, the viability of IUGR cytotrophoblasts (assessed by methyltetrazoleum assay) was significantly reduced (P < 0.001), whereas apoptosis (assessed using caspase 3/7 activity and M30 immunoreactivity) was significantly increased after T(3) treatment for 48 h (P < 0.001 and P < 0.01, respectively). The secretion of human chorionic gonadotropin was significantly increased by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), independently of T(3) treatment. Net transport of [(125)I]T(3) was 20% higher by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), and this was accompanied by a 2-fold increase in the protein expression of the TH transporter, monocarboxylate transporter 8, as assessed by Western immunoblotting (P < 0.01). CONCLUSIONS IUGR cytotrophoblasts demonstrate altered responsiveness to T(3) with significant effects on cell survival and apoptosis compared with normal cytotrophoblasts. Increased monocarboxylate transporter 8 expression and intracellular T(3) accumulation may contribute to the altered T(3) responsiveness of IUGR cytotrophoblasts.
Collapse
Affiliation(s)
- E Vasilopoulou
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
12
|
Visser WE, Friesema ECH, Visser TJ. Minireview: thyroid hormone transporters: the knowns and the unknowns. Mol Endocrinol 2010; 25:1-14. [PMID: 20660303 DOI: 10.1210/me.2010-0095] [Citation(s) in RCA: 266] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The effects of thyroid hormone (TH) on development and metabolism are exerted at the cellular level. Metabolism and action of TH take place intracellularly, which require transport of the hormone across the plasma membrane. This process is mediated by TH transporter proteins. Many TH transporters have been identified at the molecular level, although a few are classified as specific TH transporters, including monocarboxylate transporter (MCT)8, MCT10, and organic anion-transporting polypeptide 1C1. The importance of TH transporters for physiology has been illustrated dramatically by the causative role of MCT8 mutations in males with psychomotor retardation and abnormal serum TH concentrations. Although Mct8 knockout animals have provided insight in the mechanisms underlying parts of the endocrine phenotype, they lack obvious neurological abnormalities. Thus, the pathogenesis of the neurological abnormalities in males with MCT8 mutations is not fully understood. The prospects of identifying other transporters and transporter-based syndromes promise an exciting future in the TH transporter field.
Collapse
Affiliation(s)
- W Edward Visser
- Erasmus University Medical Center, Molewaterplein 50, Rotterdam, The Netherlands
| | | | | |
Collapse
|
13
|
Watkins RJ, Read ML, Smith VE, Sharma N, Reynolds GM, Buckley L, Doig C, Campbell MJ, Lewy G, Eggo MC, Loubiere LS, Franklyn JA, Boelaert K, McCabe CJ. Pituitary tumor transforming gene binding factor: a new gene in breast cancer. Cancer Res 2010; 70:3739-49. [PMID: 20406982 DOI: 10.1158/0008-5472.can-09-3531] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pituitary tumor transforming gene (PTTG) binding factor (PBF; PTTG1IP) is a relatively uncharacterized oncoprotein whose function remains obscure. Because of the presence of putative estrogen response elements (ERE) in its promoter, we assessed PBF regulation by estrogen. PBF mRNA and protein expression were induced by both diethylstilbestrol and 17beta-estradiol in estrogen receptor alpha (ERalpha)-positive MCF-7 cells. Detailed analysis of the PBF promoter showed that the region -399 to -291 relative to the translational start site contains variable repeats of an 18-bp sequence housing a putative ERE half-site (gcccctcGGTCAcgcctc). Sequencing the PBF promoter from 122 normal subjects revealed that subjects may be homozygous or heterozygous for between 1 and 6 repeats of the ERE. Chromatin immunoprecipitation and oligonucleotide pull-down assays revealed ERalpha binding to the PBF promoter. PBF expression was low or absent in normal breast tissue but was highly expressed in breast cancers. Subjects with greater numbers of ERE repeats showed higher PBF mRNA expression, and PBF protein expression positively correlated with ERalpha status. Cell invasion assays revealed that PBF induces invasion through Matrigel, an action that could be abrogated both by siRNA treatment and specific mutation. Furthermore, PBF is a secreted protein, and loss of secretion prevents PBF inducing cell invasion. Given that PBF is a potent transforming gene, we propose that estrogen treatment in postmenopausal women may upregulate PBF expression, leading to PBF secretion and increased cell invasion. Furthermore, the number of ERE half-sites in the PBF promoter may significantly alter the response to estrogen treatment in individual subjects.
Collapse
Affiliation(s)
- Rachel J Watkins
- School of Clinical and Experimental Medicine, Centre for Liver Research, Institute of Biomedical Research, and Cancer Research UK Clinical Trials Unit, School of Cancer Sciences, University of Birmingham, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Expression of thyroid hormone transporters in the human placenta and changes associated with intrauterine growth restriction. Placenta 2010; 31:295-304. [DOI: 10.1016/j.placenta.2010.01.013] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 01/21/2010] [Accepted: 01/22/2010] [Indexed: 11/24/2022]
|
15
|
Di Cosmo C, Liao XH, Dumitrescu AM, Weiss RE, Refetoff S. A thyroid hormone analog with reduced dependence on the monocarboxylate transporter 8 for tissue transport. Endocrinology 2009; 150:4450-8. [PMID: 19497976 PMCID: PMC2736078 DOI: 10.1210/en.2009-0209] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 05/28/2009] [Indexed: 11/19/2022]
Abstract
Mutations of the thyroid hormone (TH) cell membrane transporter MCT8, on chromosome-X, produce severe mental and neurological impairment in men. We generated a Mct8-deficient mouse (Mct8KO) manifesting the human thyroid phenotype. Although these mice have no neurological manifestations, they have decreased brain T(3) content and high deiodinase 2 (D2) activity, reflecting TH deprivation. In contrast and as in serum, liver T(3) content is high, resulting in increased deiodinase 1 (D1), suggesting that in this tissue TH entry is Mct8 independent. We tested the effect of 3,5-diiodothyropropionic acid (DITPA), a TH receptor agonist, for its dependence on Mct8 in Mct8KO and wild-type (Wt) mice tissues. After depletion of endogenous TH, mice were given three different doses of DITPA. Effects were compared with treatment with two doses of l-T(4). As expected, physiological doses of l-T(4) normalized serum TSH, brain D2, and liver D1 in Wt mice but not the Mct8KO mice. The higher dose of T(4) suppressed TSH in the Wt mice, normalized TSH and brain D2 in Mct8KO mice, but produced a thyrotoxic effect on liver D1 in both genotypes. In contrast DITPA produced similar effects on TSH, D2, and D1 in both Wt and Mct8KO mice. The higher dose fully normalized all measurements and other parameters of TH action. Thus, DITPA is relatively MCT8 independent for entry into the brain and corrects the TH deficit in Mct8KO mice without causing thyrotoxic effect in liver. The potential clinical utility of this analog to patients with MCT8 mutations requires further studies.
Collapse
Affiliation(s)
- Caterina Di Cosmo
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | | | |
Collapse
|
16
|
Smith VE, Read ML, Turnell AS, Watkins RJ, Watkinson JC, Lewy GD, Fong JCW, James SR, Eggo MC, Boelaert K, Franklyn JA, McCabe CJ. A novel mechanism of sodium iodide symporter repression in differentiated thyroid cancer. J Cell Sci 2009; 122:3393-402. [PMID: 19706688 DOI: 10.1242/jcs.045427] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Differentiated thyroid cancers and their metastases frequently exhibit reduced iodide uptake, impacting on the efficacy of radioiodine ablation therapy. PTTG binding factor (PBF) is a proto-oncogene implicated in the pathogenesis of thyroid cancer. We recently reported that PBF inhibits iodide uptake, and have now elucidated a mechanism by which PBF directly modulates sodium iodide symporter (NIS) activity in vitro. In subcellular localisation studies, PBF overexpression resulted in the redistribution of NIS from the plasma membrane into intracellular vesicles, where it colocalised with the tetraspanin CD63. Cell-surface biotinylation assays confirmed a reduction in plasma membrane NIS expression following PBF transfection compared with vector-only treatment. Coimmunoprecipitation and GST-pull-down experiments demonstrated a direct interaction between NIS and PBF, the functional consequence of which was assessed using iodide-uptake studies in rat thyroid FRTL-5 cells. PBF repressed iodide uptake, whereas three deletion mutants, which did not localise within intracellular vesicles, lost the ability to inhibit NIS activity. In summary, we present an entirely novel mechanism by which the proto-oncogene PBF binds NIS and alters its subcellular localisation, thereby regulating its ability to uptake iodide. Given that PBF is overexpressed in thyroid cancer, these findings have profound implications for thyroid cancer ablation using radioiodine.
Collapse
Affiliation(s)
- Vicki E Smith
- School of Clinical and Experimental Medicine, Institute of Biomedical Research, University of Birmingham B15 2TH, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|