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Peng W, Shi S, Yang L, Liu D. Identification of a novel nonsense SLC16A2 gene mutation in an infant with severe neurologic phenotype: A case report. Medicine (Baltimore) 2024; 103:e39047. [PMID: 39029020 PMCID: PMC11398793 DOI: 10.1097/md.0000000000039047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/21/2024] Open
Abstract
RATIONALE Allan-Herndon-Dudley syndrome (AHDS) results from a pathogenic variant in the hemizygous subunit of the SLC16A2 gene, which encodes monocarboxylate transporter 8 and follows an X-linked recessive pattern. AHDS manifests as neuropsychomotor developmental delay, intellectual disability, movement disorders, and thyroid hormone abnormalities. It is frequently misdiagnosed as cerebral palsy or hypothyroidism. PATIENT CONCERNS A 9-month-old male infant exhibited poor head control, hypodynamia, motor retardation, hypertonic limbs, and thyroid abnormalities. Despite levothyroxine supplementation and rehabilitation therapy, no improvements were observed. Whole-exome sequencing identified a novel nonsense mutation in SLC16A2 (c.124G > T, p.E42X), which unequivocally established the diagnosis. DIAGNOSES AHDS was confirmed. INTERVENTIONS Levothyroxine treatment commenced early in infancy, followed by 3 months of rehabilitation therapy, starting at 5 months of age. The combined administration of levothyroxine and methimazole was initiated at 1 year and 10 months of age, respectively. OUTCOMES While improvements were noted in thyroid hormone levels, neurological developmental delays persisted. LESSONS AHDS should be considered in patients presenting with atypical neurological features and thyroid hormone abnormalities such as elevated triiodothyronine and decreased thyroxine levels. The early utilization of exome sequencing aids in prompt diagnosis. The identified SLC16A2 nonsense mutation correlates with severe neurological phenotypes and adds to the spectrum of genetic variations associated with AHDS.
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Affiliation(s)
- Wu Peng
- Department of Pediatrics, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Shuxia Shi
- Department of Clinical Medicine, Anhui Medical College, Hefei, China
| | - Liqi Yang
- Department of Pediatrics, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Deyun Liu
- Department of Pediatrics, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
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Salas-Lucia F. Mapping Thyroid Hormone Action in the Human Brain. Thyroid 2024; 34:815-826. [PMID: 38757586 PMCID: PMC11295854 DOI: 10.1089/thy.2024.0120] [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] [Indexed: 05/18/2024]
Abstract
Background: Normal brain development, mood, and cognitive functions depend on thyroid hormone (TH) action. However, little is known about how TH mediates its actions in the human brain. This is due to limited access to human brains deprived of TH during fetal and early postnatal life, as well as from adults with altered thyroid status. One way to partially bypass these limitations is by using magnetic resonance imaging and spectroscopy, two neuroimaging techniques that provide detailed, noninvasive information on human brain structure and function. Another way is using human-induced pluripotent stem cell (hiPSCs)-derived three-dimensional in vitro systems, known as brain organoids, which allow for the study of fundamental aspects of the early stages of human brain development. Summary: This narrative review focuses on neuroimaging and brain organoid studies. Neuroimaging of human brains performed in individuals with different thyroid conditions provides information on the volume, myelination, blood flow, neural activity, and connectivity of different areas. Such studies show that suboptimal thyroid status can impact human brain development and its normal function throughout life. This is true not only for patients with sporadic congenital hypothyroidism, during pregnancy or early after birth, but also for adult patients with hypo- or hyperthyroidism, patients carrying mutations that manifest as impaired sensitivity to TH, and even for normal individuals during aging. Studies using brain organoids generated from hiPSCs of healthy individuals or patients with thyroid genetic conditions provide insights into how TH can impact the early development of the human cerebral cortex. Conclusions: The developmental alterations in children born to mothers with different degrees of gestational hypothyroidism or who developed hypothyroidism early in life are remarkable, affecting multiple brain regions and pathways, including the cerebral cortex, hippocampus, cerebellum, interhemispheric and corticospinal tracts, and associative nuclei. The data connecting such changes to poor neurological outcomes in adult patients with hypothyroidism represent an objective link between thyroid-specific functional brain alterations and behavior. Growing brain organoids require TH, which is critical for human neurogenesis and oligodendrogenesis. These models have proven useful in screening drugs with potential therapeutic effects for patients with genetic thyroid diseases.
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Mura E, Parazzini C, Tonduti D. Rare forms of hypomyelination and delayed myelination. HANDBOOK OF CLINICAL NEUROLOGY 2024; 204:225-252. [PMID: 39322381 DOI: 10.1016/b978-0-323-99209-1.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/27/2024]
Abstract
Hypomyelination is defined by the evidence of an unchanged pattern of deficient myelination on two MRIs performed at least 6 months apart in a child older than 1 year. When the temporal criteria are not fulfilled, and the follow-up MRI shows a progression of the myelination even if still not adequate for age, hypomyelination is excluded and the pattern is instead consistent with delayed myelination. This can be mild and nonspecific in some cases, while in other cases there is a severe delay that in the first disease stages could be difficult to differentiate from hypomyelination. In hypomyelinating leukodystrophies, hypomyelination is due to a primary impairment of myelin deposition, such as in Pelizaeus Merzabcher disease. Conversely, myelin lack is secondary, often to primary neuronal disorders, in delayed myelination and some condition with hypomyelination. Overall, the group of inherited white matter disorders with abnormal myelination has expanded significantly during the past 20 years. Many of these disorders have only recently been described, for many of them only a few patients have been reported and this contributes to make challenging the diagnostic process and the interpretation of Next Generation Sequencing results. In this chapter, we review the clinical and radiologic features of rare and lesser known forms of hypomyelination and delayed myelination not mentioned in other chapters of this handbook.
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Affiliation(s)
- Eleonora Mura
- Unit of Pediatric Neurology, Department of Biomedical and Clinical Sciences, V. Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy; C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy
| | - Cecilia Parazzini
- C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy; Pediatric Radiology and Neuroradiology Department, V. Buzzi Children's Hospital, Milan, Italy
| | - Davide Tonduti
- Unit of Pediatric Neurology, Department of Biomedical and Clinical Sciences, V. Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy; C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy.
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Wilpert NM, Tonduti D, Vaia Y, Krude H, Sarret C, Schuelke M. Establishing Patient-Centered Outcomes for MCT8 Deficiency: Stakeholder Engagement and Systematic Literature Review. Neuropsychiatr Dis Treat 2023; 19:2195-2216. [PMID: 37881807 PMCID: PMC10595182 DOI: 10.2147/ndt.s379703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 10/07/2023] [Indexed: 10/27/2023] Open
Abstract
Introduction The SCL16A2 gene encodes the thyroid hormone (TH) transporter MCT8. Pathogenic variants result in a reduced TH uptake into the CNS despite high serum T3 concentrations. Patients suffer from severe neurodevelopmental delay and require multidisciplinary care. Since a first compassionate use study in 2008, the development of therapies has recently gained momentum. Treatment strategies range from symptom-based approaches, supplementation with TH or TH-analogs, to gene therapy. All these studies have mainly used surrogate endpoints and clinical outcomes. However, the EMA and FDA strongly encourage researchers to involve patients and their advocacy groups in the design of clinical trials. This should strengthen the patients' perspective and identify clinical endpoints that are clinically relevant to their daily life. Methods We involved patient families to define patient-relevant outcomes for MCT8 deficiency. In close collaboration with patient families, we designed a questionnaire asking for their five most preferred therapeutic goals, which, if achieved at least, make a difference in their lives. In addition, we performed a systematic review according to Cochrane recommendations of the published treatment trials. Results We obtained results from 15 families with completed questionnaires from 14 mothers and 8 fathers. Improvement in development, especially in gross motor skills, was most important to the parents. 59% wished for head control and 50% for sitting ability. Another 36% wished for weight gain, 32% for improvement of expressive language skills, and 18% for a reduction of dystonia/spasticity, less dysphagia, and reflux. Paraclinical aspects were least important (5-9%). In a treatment trial (n=46) and compassionate use cases (n=83), the results were mainly inconclusive, partly due to a lack of predefined patient-centered clinical endpoints. Discussion We recommend that future trials should define a relevant improvement in "development" and/or other patient-relevant outcomes compared to natural history as treatment goals.
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Affiliation(s)
- Nina-Maria Wilpert
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Department of Pediatric Neurology, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health (BIH), Center for Chronically Sick Children, Berlin, Germany
| | - Davide Tonduti
- Unit of Pediatric Neurology, C.O.A.L.A. (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children’s Hospital, Università Degli Studi Di Milano, Milan, Italy
| | - Ylenia Vaia
- Unit of Pediatric Neurology, C.O.A.L.A. (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children’s Hospital, Università Degli Studi Di Milano, Milan, Italy
| | - Heiko Krude
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Catherine Sarret
- Centre de Compétence des Leucodystrophies et Leucoencéphalopathies de Cause Rare, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - Markus Schuelke
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Department of Pediatric Neurology, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health (BIH), Center for Chronically Sick Children, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), NeuroCure Clinical Research Center, Berlin, Germany
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Siemes D, Vancamp P, Markova B, Spangenberg P, Shevchuk O, Siebels B, Schlüter H, Mayerl S, Heuer H, Engel DR. Proteome Analysis of Thyroid Hormone Transporter Mct8/Oatp1c1-Deficient Mice Reveals Novel Dysregulated Target Molecules Involved in Locomotor Function. Cells 2023; 12:2487. [PMID: 37887331 PMCID: PMC10605308 DOI: 10.3390/cells12202487] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/28/2023] Open
Abstract
Thyroid hormone (TH) transporter MCT8 deficiency causes severe locomotor disabilities likely due to insufficient TH transport across brain barriers and, consequently, compromised neural TH action. As an established animal model for this disease, Mct8/Oatp1c1 double knockout (DKO) mice exhibit strong central TH deprivation, locomotor impairments and similar histo-morphological features as seen in MCT8 patients. The pathways that cause these neuro-motor symptoms are poorly understood. In this paper, we performed proteome analysis of brain sections comprising cortical and striatal areas of 21-day-old WT and DKO mice. We detected over 2900 proteins by liquid chromatography mass spectrometry, 67 of which were significantly different between the genotypes. The comparison of the proteomic and published RNA-sequencing data showed a significant overlap between alterations in both datasets. In line with previous observations, DKO animals exhibited decreased myelin-associated protein expression and altered protein levels of well-established neuronal TH-regulated targets. As one intriguing new candidate, we unraveled and confirmed the reduced protein and mRNA expression of Pde10a, a striatal enzyme critically involved in dopamine receptor signaling, in DKO mice. As altered PDE10A activities are linked to dystonia, reduced basal ganglia PDE10A expression may represent a key pathogenic pathway underlying human MCT8 deficiency.
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Affiliation(s)
- Devon Siemes
- Department of Immunodynamics, Institute for Experimental Immunology and Imaging, University Duisburg-Essen, 45141 Essen, Germany; (D.S.); (P.S.); (O.S.); (D.R.E.)
| | - Pieter Vancamp
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (P.V.); (B.M.); (S.M.)
| | - Boyka Markova
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (P.V.); (B.M.); (S.M.)
| | - Philippa Spangenberg
- Department of Immunodynamics, Institute for Experimental Immunology and Imaging, University Duisburg-Essen, 45141 Essen, Germany; (D.S.); (P.S.); (O.S.); (D.R.E.)
| | - Olga Shevchuk
- Department of Immunodynamics, Institute for Experimental Immunology and Imaging, University Duisburg-Essen, 45141 Essen, Germany; (D.S.); (P.S.); (O.S.); (D.R.E.)
| | - Bente Siebels
- Section Mass Spectrometric Proteomics, Diagnostic Center, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (B.S.); (H.S.)
| | - Hartmut Schlüter
- Section Mass Spectrometric Proteomics, Diagnostic Center, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (B.S.); (H.S.)
| | - Steffen Mayerl
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (P.V.); (B.M.); (S.M.)
| | - Heike Heuer
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (P.V.); (B.M.); (S.M.)
| | - Daniel Robert Engel
- Department of Immunodynamics, Institute for Experimental Immunology and Imaging, University Duisburg-Essen, 45141 Essen, Germany; (D.S.); (P.S.); (O.S.); (D.R.E.)
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Wang T, Wang Y, Montero-Pedrazuela A, Prensa L, Guadaño-Ferraz A, Rausell E. Thyroid Hormone Transporters MCT8 and OATP1C1 Are Expressed in Projection Neurons and Interneurons of Basal Ganglia and Motor Thalamus in the Adult Human and Macaque Brains. Int J Mol Sci 2023; 24:9643. [PMID: 37298594 PMCID: PMC10254002 DOI: 10.3390/ijms24119643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/29/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Monocarboxylate transporter 8 (MCT8) and organic anion-transporting polypeptide 1C1 (OATP1C1) are thyroid hormone (TH) transmembrane transporters relevant for the availability of TH in neural cells, crucial for their proper development and function. Mutations in MCT8 or OATP1C1 result in severe disorders with dramatic movement disability related to alterations in basal ganglia motor circuits. Mapping the expression of MCT8/OATP1C1 in those circuits is necessary to explain their involvement in motor control. We studied the distribution of both transporters in the neuronal subpopulations that configure the direct and indirect basal ganglia motor circuits using immunohistochemistry and double/multiple labeling immunofluorescence for TH transporters and neuronal biomarkers. We found their expression in the medium-sized spiny neurons of the striatum (the receptor neurons of the corticostriatal pathway) and in various types of its local microcircuitry interneurons, including the cholinergic. We also demonstrate the presence of both transporters in projection neurons of intrinsic and output nuclei of the basal ganglia, motor thalamus and nucleus basalis of Meynert, suggesting an important role of MCT8/OATP1C1 for modulating the motor system. Our findings suggest that a lack of function of these transporters in the basal ganglia circuits would significantly impact motor system modulation, leading to clinically severe movement impairment.
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Affiliation(s)
- Ting Wang
- School of Medicine, Department Anatomy Histology & Neuroscience, Autónoma de Madrid University (UAM), 28029 Madrid, Spain; (T.W.); (Y.W.); (L.P.)
- PhD Program in Neuroscience, Autónoma de Madrid University (UAM)-Cajal Institute, 28029 Madrid, Spain
| | - Yu Wang
- School of Medicine, Department Anatomy Histology & Neuroscience, Autónoma de Madrid University (UAM), 28029 Madrid, Spain; (T.W.); (Y.W.); (L.P.)
- PhD Program in Neuroscience, Autónoma de Madrid University (UAM)-Cajal Institute, 28029 Madrid, Spain
| | - Ana Montero-Pedrazuela
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-Autónoma de Madrid University (UAM), 28029 Madrid, Spain;
| | - Lucía Prensa
- School of Medicine, Department Anatomy Histology & Neuroscience, Autónoma de Madrid University (UAM), 28029 Madrid, Spain; (T.W.); (Y.W.); (L.P.)
| | - Ana Guadaño-Ferraz
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-Autónoma de Madrid University (UAM), 28029 Madrid, Spain;
| | - Estrella Rausell
- School of Medicine, Department Anatomy Histology & Neuroscience, Autónoma de Madrid University (UAM), 28029 Madrid, Spain; (T.W.); (Y.W.); (L.P.)
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Thyroid Hormone Transporters MCT8 and OATP1C1 Are Expressed in Pyramidal Neurons and Interneurons in the Adult Motor Cortex of Human and Macaque Brain. Int J Mol Sci 2023; 24:ijms24043207. [PMID: 36834621 PMCID: PMC9965431 DOI: 10.3390/ijms24043207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/26/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Monocarboxylate transporter 8 (MCT8) and organic anion transporter polypeptide 1C1 (OATP1C1) are thyroid hormone (TH) transmembrane transporters that play an important role in the availability of TH for neural cells, allowing their proper development and function. It is important to define which cortical cellular subpopulations express those transporters to explain why MCT8 and OATP1C1 deficiency in humans leads to dramatic alterations in the motor system. By means of immunohistochemistry and double/multiple labeling immunofluorescence in adult human and monkey motor cortices, we demonstrate the presence of both transporters in long-projection pyramidal neurons and in several types of short-projection GABAergic interneurons in both species, suggesting a critical position of these transporters for modulating the efferent motor system. MCT8 is present at the neurovascular unit, but OATP1C1 is only present in some of the large vessels. Both transporters are expressed in astrocytes. OATP1C1 was unexpectedly found, only in the human motor cortex, inside the Corpora amylacea complexes, aggregates linked to substance evacuation towards the subpial system. On the basis of our findings, we propose an etiopathogenic model that emphasizes these transporters' role in controlling excitatory/inhibitory motor cortex circuits in order to understand some of the severe motor disturbances observed in TH transporter deficiency syndromes.
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Reinwald JR, Weber-Fahr W, Cosa-Linan A, Becker R, Sack M, Falfan-Melgoza C, Gass N, Braun U, Clemm von Hohenberg C, Chen J, Mayerl S, Muente TF, Heuer H, Sartorius A. TRIAC Treatment Improves Impaired Brain Network Function and White Matter Loss in Thyroid Hormone Transporter Mct8/Oatp1c1 Deficient Mice. Int J Mol Sci 2022; 23:15547. [PMID: 36555189 PMCID: PMC9779161 DOI: 10.3390/ijms232415547] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
Dysfunctions of the thyroid hormone (TH) transporting monocarboxylate transporter MCT8 lead to a complex X-linked syndrome with abnormal serum TH concentrations and prominent neuropsychiatric symptoms (Allan-Herndon-Dudley syndrome, AHDS). The key features of AHDS are replicated in double knockout mice lacking MCT8 and organic anion transporting protein OATP1C1 (Mct8/Oatp1c1 DKO). In this study, we characterize impairments of brain structure and function in Mct8/Oatp1c1 DKO mice using multimodal magnetic resonance imaging (MRI) and assess the potential of the TH analogue 3,3',5-triiodothyroacetic acid (TRIAC) to rescue this phenotype. Structural and functional MRI were performed in 11-weeks-old male Mct8/Oatp1c1 DKO mice (N = 10), wild type controls (N = 7) and Mct8/Oatp1c1 DKO mice (N = 13) that were injected with TRIAC (400 ng/g bw s.c.) daily during the first three postnatal weeks. Grey and white matter volume were broadly reduced in Mct8/Oatp1c1 DKO mice. TRIAC treatment could significantly improve white matter thinning but did not affect grey matter loss. Network-based statistic showed a wide-spread increase of functional connectivity, while graph analysis revealed an impairment of small-worldness and whole-brain segregation in Mct8/Oatp1c1 DKO mice. Both functional deficits could be substantially ameliorated by TRIAC treatment. Our study demonstrates prominent structural and functional brain alterations in Mct8/Oatp1c1 DKO mice that may underlie the psychomotor deficiencies in AHDS. Additionally, we provide preclinical evidence that early-life TRIAC treatment improves white matter loss and brain network dysfunctions associated with TH transporter deficiency.
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Affiliation(s)
- Jonathan Rochus Reinwald
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
- Research Group Systems Neuroscience and Mental Health, Department of Psychiatry and Psychotherapy, University Medical Center Mainz, 55131 Mainz, Germany
| | - Wolfgang Weber-Fahr
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Alejandro Cosa-Linan
- Research Group in Silico Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Robert Becker
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
- Center for Innovative Psychiatry and Psychotherapy Research, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Markus Sack
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
- Center for Innovative Psychiatry and Psychotherapy Research, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Claudia Falfan-Melgoza
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Natalia Gass
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Urs Braun
- Research Group Systems Neuroscience in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Christian Clemm von Hohenberg
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - Jiesi Chen
- Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Steffen Mayerl
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Thomas F. Muente
- Department of Neurology, University of Lübeck, 23538 Lübeck, Germany
| | - Heike Heuer
- Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Alexander Sartorius
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
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9
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Vatine GD, Shelest O, Barriga BK, Ofan R, Rabinski T, Mattis VB, Heuer H, Svendsen CN. Oligodendrocyte progenitor cell maturation is dependent on dual function of MCT8 in the transport of thyroid hormone across brain barriers and the plasma membrane. Glia 2021; 69:2146-2159. [PMID: 33956384 DOI: 10.1002/glia.24014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 11/09/2022]
Abstract
Inactivating mutations in the thyroid hormone (TH) transporter monocarboxylate transporter 8 (MCT8) causes a rare and debilitating form of X-linked psychomotor disability known as Allan Herndon Dudley syndrome (AHDS). One of the most prominent pathophysiological symptoms of MCT8-deficiency is hypomyelination. Here, patient-derived induced pluripotent stem cells (iPSCs) were used to study the role of MCT8 and TH on the maturation of oligodendrocytes. Interestingly, neither MCT8 mutations nor reduced TH affected the in vitro differentiation of control or MCT8-deficient iPSCs into oligodendrocytes. To assess whether patient-derived iPSC-derived oligodendrocyte progenitor cells (iOPCs) could provide myelinating oligodendrocytes in vivo, cells were transplanted into the shiverer mouse corpus callosum where they survived, migrated, and matured into myelinating oligodendrocytes, though the myelination efficiency was reduced compared with control cells. When MCT8-deficient and healthy control iOPCs were transplanted into a novel hypothyroid immunodeficient triple knockout mouse (tKO, mct8-/- ; oatp1c1-/- ; rag2-/- ), they failed to provide behavioral recovery and did not mature into oligodendrocytes in the hypothyroid corpus callosum, demonstrating the critical role of TH transport across brain barriers in oligodendrocyte maturation. We conclude that MCT8 plays a cell autonomous role in oligodendrocyte maturation and that functional TH transport into the central nervous system will be required for developing an effective treatment for MCT8-deficient patients.
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Affiliation(s)
- Gad D Vatine
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.,The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva, Israel.,The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Oksana Shelest
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Bianca K Barriga
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Raz Ofan
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.,The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva, Israel.,The Department of Biotechnology Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Tatyana Rabinski
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Virginia B Mattis
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,FUJIFILM Cellular Dynamics Inc., Madison, Wisconsin, USA
| | - Heike Heuer
- Department of Endocrinology, Diabetes and Metabolism, University of Duisburg-Essen, Essen, Germany
| | - Clive N Svendsen
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
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Abstract
Hypomyelinating leukodystrophies constitute a subset of genetic white matter disorders characterized by a primary lack of myelin deposition. Most patients with severe hypomyelination present in infancy or early childhood and develop severe neurological deficits, but the clinical presentation can also be mild with onset of symptoms in adolescence or adulthood. MRI can be used to visualize the process of myelination in detail, and MRI pattern recognition can provide a clinical diagnosis in many patients. Next-generation sequencing provides a definitive diagnosis in 80-90% of patients. Genes associated with hypomyelination include those that encode structural myelin proteins but also many that encode proteins involved in RNA translation and some lysosomal proteins. The precise pathomechanisms remain to be elucidated. Improved understanding of the process of myelination, the metabolic axonal support functions of myelin and the proposed contribution of myelin to CNS plasticity provide possible explanations as to why almost all patients with hypomyelination experience slow clinical decline after a long phase of stability. In this Review, we provide an overview of the hypomyelinating leukodystrophies, the advances in our understanding of myelin biology and of the genes involved in these disorders, and the insights these advances have provided into their clinical presentations and evolution.
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11
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Ahn H, Ko TS. The Genetic Relationship between Paroxysmal Movement Disorders and Epilepsy. ANNALS OF CHILD NEUROLOGY 2020. [DOI: 10.26815/acn.2020.00073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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12
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Malik P, Muthusamy K, Mankad K, Shroff M, Sudhakar S. Solving the hypomyelination conundrum - Imaging perspectives. Eur J Paediatr Neurol 2020; 27:9-24. [PMID: 32418752 DOI: 10.1016/j.ejpn.2020.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 03/25/2020] [Accepted: 04/14/2020] [Indexed: 11/26/2022]
Abstract
Hypomyelinating Leukodystrophies (HLDs) are a genetically heterogeneous, clinically overlapping group of disorders with the unifying MR imaging appearance of myelin deficit in the brain. In fact, it is the MRI phenotype that typically raises the diagnostic suspicion in this single largest group of undiagnosed leukodystrophies and guides gene testing for confirmation. This article reviews the neurobiology of myelination, focussing on the complex interplay of molecular genetic pathways and presents a practical clinico-radiological diagnostic algorithm based on the neuroimaging patterns of the common hypomyelinating disorders. The authors also address the current controversies about the definition and use of the term 'hypomyelination'.
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13
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Groeneweg S, van Geest FS, Peeters RP, Heuer H, Visser WE. Thyroid Hormone Transporters. Endocr Rev 2020; 41:5637505. [PMID: 31754699 DOI: 10.1210/endrev/bnz008] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/07/2019] [Indexed: 02/08/2023]
Abstract
Thyroid hormone transporters at the plasma membrane govern intracellular bioavailability of thyroid hormone. Monocarboxylate transporter (MCT) 8 and MCT10, organic anion transporting polypeptide (OATP) 1C1, and SLC17A4 are currently known as transporters displaying the highest specificity toward thyroid hormones. Structure-function studies using homology modeling and mutational screens have led to better understanding of the molecular basis of thyroid hormone transport. Mutations in MCT8 and in OATP1C1 have been associated with clinical disorders. Different animal models have provided insight into the functional role of thyroid hormone transporters, in particular MCT8. Different treatment strategies for MCT8 deficiency have been explored, of which thyroid hormone analogue therapy is currently applied in patients. Future studies may reveal the identity of as-yet-undiscovered thyroid hormone transporters. Complementary studies employing animal and human models will provide further insight into the role of transporters in health and disease. (Endocrine Reviews 41: 1 - 55, 2020).
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Affiliation(s)
- Stefan Groeneweg
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Ferdy S van Geest
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Robin P Peeters
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Heike Heuer
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - W Edward Visser
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, the Netherlands
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14
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Papandreou A, Danti FR, Spaull R, Leuzzi V, Mctague A, Kurian MA. The expanding spectrum of movement disorders in genetic epilepsies. Dev Med Child Neurol 2020; 62:178-191. [PMID: 31784983 DOI: 10.1111/dmcn.14407] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2019] [Indexed: 12/27/2022]
Abstract
An ever-increasing number of neurogenetic conditions presenting with both epilepsy and atypical movements are now recognized. These disorders within the 'genetic epilepsy-dyskinesia' spectrum are clinically and genetically heterogeneous. Increased clinical awareness is therefore necessary for a rational diagnostic approach. Furthermore, careful interpretation of genetic results is key to establishing the correct diagnosis and initiating disease-specific management strategies in a timely fashion. In this review we describe the spectrum of movement disorders associated with genetically determined epilepsies. We also propose diagnostic strategies and putative pathogenic mechanisms causing these complex syndromes associated with both seizures and atypical motor control. WHAT THIS PAPER ADDS: Implicated genes encode proteins with very diverse functions. Pathophysiological mechanisms by which epilepsy and movement disorder phenotypes manifest are often not clear. Early diagnosis of treatable disorders is essential and next generation sequencing may be required.
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Affiliation(s)
- Apostolos Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Federica Rachele Danti
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Robert Spaull
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Amy Mctague
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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15
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Vancamp P, Demeneix BA, Remaud S. Monocarboxylate Transporter 8 Deficiency: Delayed or Permanent Hypomyelination? Front Endocrinol (Lausanne) 2020; 11:283. [PMID: 32477268 PMCID: PMC7237703 DOI: 10.3389/fendo.2020.00283] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/15/2020] [Indexed: 12/11/2022] Open
Abstract
Monocarboxylate transporter 8 (MCT8) deficiency or the Allan-Herndon-Dudley Syndrome (AHDS) is an X-linked psychomotor disability syndrome with around 320 clinical cases described worldwide. SLC16A2 gene mutations, encoding the thyroid hormone (TH) transporter MCT8, result in intellectual disability due to impaired TH uptake in the developing brain. MCT8 deficiency is a multi-organ affecting disease with a predominant neuronal cell-based pathology, with the glial component inadequately investigated. However, deficiency in myelin, a key component of white matter (WM) enabling fast nerve conduction, is a TH-dependent hallmark of the disease. Nevertheless, analysis of the myelin status in AHDS patients has led to conflicting interpretations. The majority of individual case studies reported delayed myelination, that was restored later in life. In contrast, post-mortem studies and high-resolution MRIs detected WM (micro-) abnormalities throughout adolescence, suggesting permanent hypomyelination. Thus, interpretations vary depending on methodology to investigate WM microstructure. Further, it is unknown whether the mutation within the MCT8 is linked to the severity of the myelin deficiency. Consequently, terminology is inconsistent among reports, and AHDS is occasionally misdiagnosed as another WM disorder. The evolutionary conserved TH signaling pathway that promotes the generation of myelinating oligodendrocytes enabled deciphering how the lack of MCT8 might affect myelinogenesis. Linking patient findings on myelination to those obtained from models of MCT8 deficiency revealed underlying pathophysiological mechanisms, but knowledge gaps remain, notably how myelination progresses both spatially and temporally in MCT8 deficiency. This limits predicting how myelin integrity might benefit therapeutically, and when to initiate. A recurrent observation in clinical trials is the absence of neurological improvement. Testing MCT8-independent thyromimetics in models, and evaluating treatments used in other demyelinating diseases, despite different etiologies, is crucial to propose new therapeutic strategies combatting this devastating disease.
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Affiliation(s)
- Pieter Vancamp
- UMR 7221 Molecular Physiology and Adaptation, Centre National de le Recherche Scientifique-Muséum National d'Histoire Naturelle, Paris, France
| | - Barbara A Demeneix
- UMR 7221 Molecular Physiology and Adaptation, Centre National de le Recherche Scientifique-Muséum National d'Histoire Naturelle, Paris, France
| | - Sylvie Remaud
- UMR 7221 Molecular Physiology and Adaptation, Centre National de le Recherche Scientifique-Muséum National d'Histoire Naturelle, Paris, France
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16
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Remerand G, Boespflug-Tanguy O, Tonduti D, Touraine R, Rodriguez D, Curie A, Perreton N, Des Portes V, Sarret C. Expanding the phenotypic spectrum of Allan-Herndon-Dudley syndrome in patients with SLC16A2 mutations. Dev Med Child Neurol 2019; 61:1439-1447. [PMID: 31410843 DOI: 10.1111/dmcn.14332] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/07/2019] [Indexed: 01/01/2023]
Abstract
The aim of the study was to redefine the phenotype of Allan-Herndon-Dudley syndrome (AHDS), which is caused by mutations in the SLC16A2 gene that encodes the brain transporter of thyroid hormones. Clinical phenotypes, brain imaging, thyroid hormone profiles, and genetic data were compared to the existing literature. Twenty-four males aged 11 months to 29 years had a mutation in SLC16A2, including 12 novel mutations and five previously described mutations. Sixteen patients presented with profound developmental delay, three had severe intellectual disability with poor language and walking with an aid, four had moderate intellectual disability with language and walking abilities, and one had mild intellectual disability with hypotonia. Overall, eight had learned to walk, all had hypotonia, 17 had spasticity, 18 had dystonia, 12 had choreoathetosis, 19 had hypomyelination, and 10 had brain atrophy. Kyphoscoliosis (n=12), seizures (n=7), and pneumopathies (n=5) were the most severe complications. This study extends the phenotypic spectrum of AHDS to a mild intellectual disability with hypotonia. Developmental delay, hypotonia, hypomyelination, and thyroid hormone profile help to diagnose patients. Clinical course depends on initial severity, with stable acquisition after infancy; this may be adversely affected by neuro-orthopaedic, pulmonary, and epileptic complications. WHAT THIS PAPER ADDS: Mild intellectual disability is associated with SLC16A2 mutations. A thyroid hormone profile with a free T3 /T4 ratio higher than 0.75 can help diagnose patients. Patients with SLC16A2 mutations present a broad spectrum of neurological phenotypes that are also observed in other hypomyelinating disorders. Axial hypotonia is a consistent feature of Allan-Herndon-Dudley syndrome and leads to specific complications.
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Affiliation(s)
- Ganaelle Remerand
- Centre de Compétence des Leucodystrophies et Leucoencéphalopathies de Cause Rare, Pôle Femme et Enfant, Hôpital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - Odile Boespflug-Tanguy
- Centre de Référence des Leucodystrophies et Leucoencéphalopathies de Cause Rare, Service de Neurologie Pédiatrique, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, Paris, France.,NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Paris, France
| | - Davide Tonduti
- Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Unit of Child Neurology, V. Buzzi Children's Hospital, Milan, Italy
| | - Renaud Touraine
- Service de Génétique, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Etienne, France
| | - Diana Rodriguez
- Sorbonne Université, GRC no. 19, Pathologies Congénitales du Cervelet-LeucoDystrophies, Assistance Publique-Hôpitaux de Paris, Hôpital Armand Trousseau, Paris, France.,Centre de Référence Neurogénétique, Service de Neurologie Pédiatrique, Assistance Publique-Hôpitaux de Paris, Hôpital Armand Trousseau, Paris, France
| | - Aurore Curie
- Centre de Référence des Déficiences Intellectuelles de Cause Rare, Service de Neurologie Pédiatrique, Centre Hospitalier Universitaire de Lyon, Hôpital Femme-Mère-Enfant, Lyon, France
| | - Nathalie Perreton
- CIC 1407Inserm, Centre Hospitalo-Universitaire de Lyon, Lyon, France
| | - Vincent Des Portes
- Centre de Référence des Déficiences Intellectuelles de Cause Rare, Service de Neurologie Pédiatrique, Centre Hospitalier Universitaire de Lyon, Hôpital Femme-Mère-Enfant, Lyon, France
| | - Catherine Sarret
- Centre de Compétence des Leucodystrophies et Leucoencéphalopathies de Cause Rare, Pôle Femme et Enfant, Hôpital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France.,IGCNC, Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut Pascal, Clermont-Ferrand, France
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17
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Masnada S, Groenweg S, Saletti V, Chiapparini L, Castellotti B, Salsano E, Visser WE, Tonduti D. Novel mutations in SLC16A2 associated with a less severe phenotype of MCT8 deficiency. Metab Brain Dis 2019; 34:1565-1575. [PMID: 31332729 DOI: 10.1007/s11011-019-00464-7] [Citation(s) in RCA: 9] [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] [Received: 04/18/2019] [Accepted: 07/08/2019] [Indexed: 02/08/2023]
Abstract
Mutations in the thyroid hormone transporter MCT8 cause severe intellectual and motor disability and abnormal serum thyroid function tests, a syndrome known as MCT8 deficiency (or: Allan-Herndon-Dudley syndrome, AHDS). Although the majority of patients are unable to sit or walk independently and do not develop any speech, some are able to walk and talk in simple sentences. Here, we report on two cases with such a less severe clinical phenotype and consequent gross delay in diagnosis. Genetic analyses revealed two novel hemizygous mutations in the SLC16A2 gene resulting in a p.Thr239Pro and a p.Leu543Pro substitution in the MCT8 protein. In vitro studies in transiently transfected COS-1 and JEG-3 cells, and ex vivo studies in patient-derived fibroblasts revealed substantial residual uptake capacity of both mutant proteins (Leu543Pro > Thr239Pro), providing an explanation for the less severe clinical phenotype. Both mutations impair MCT8 protein stability and interfere with proper subcellular trafficking. In one of the patients calcifications were observed in the basal ganglia at the age of 29 years; an abnormal neuroradiological feature at this age that has been linked to untreated (congenital) hypothyroidism and neural cretinism. Our studies extend on previous work by identifying two novel pathogenic mutations in SLC16A2 gene resulting in a mild clinical phenotype.
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Affiliation(s)
- Silvia Masnada
- Pediatric Neurology Unit, V. Buzzi Children's Hospital, Via Castelvetro 32, 20154, Milan, Italy
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | - Stefan Groenweg
- Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus MC, University Medical Center, CN, Rotterdam, The Netherlands
| | - Veronica Saletti
- Child Neurology Department, IRCCS Foundation C. Besta Neurological Institute, Milan, Italy
| | - Luisa Chiapparini
- Neuroradiology Unit, IRCCS Foundation C. Besta Neurological Institute, Milan, Italy
| | - Barbara Castellotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Foundation C. Besta Neurological Institute, Milan, Italy
| | - Ettore Salsano
- Unit of Neurodegenerative and Neurometabolic Rare Diseases, IRCCS Foundation C. Besta Neurological Institute, Milan, Italy
| | - W Edward Visser
- Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus MC, University Medical Center, CN, Rotterdam, The Netherlands
| | - Davide Tonduti
- Pediatric Neurology Unit, V. Buzzi Children's Hospital, Via Castelvetro 32, 20154, Milan, Italy.
- Child Neurology Department, IRCCS Foundation C. Besta Neurological Institute, Milan, Italy.
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18
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Walter KM, Dach K, Hayakawa K, Giersiefer S, Heuer H, Lein PJ, Fritsche E. Ontogenetic expression of thyroid hormone signaling genes: An in vitro and in vivo species comparison. PLoS One 2019; 14:e0221230. [PMID: 31513589 PMCID: PMC6742404 DOI: 10.1371/journal.pone.0221230] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/01/2019] [Indexed: 02/07/2023] Open
Abstract
Thyroid hormone (TH) is essential for brain development. While disruption of TH signaling by environmental chemicals has been discussed as a mechanism of developmental neurotoxicity (DNT) for more than a decade, there remains a paucity of information linking specific TH disrupting chemicals to adverse neurodevelopmental outcomes. This data gap reflects, in part, the fact that the molecular machinery of TH signaling is complex and varies according to cell type and developmental time. Thus, establishing a baseline of the ontogenetic profile of expression of TH signaling molecules in relevant cell types is critical for developing in vitro and alternative systems-based models for screening TH disrupting chemicals for DNT. Here, we characterize the transcriptomic profile of molecules critical to TH signaling across three species-human, rat, and zebrafish-in vitro and in vivo across different stages of neurodevelopment. Our data indicate that while cultured human and rat neural progenitor cells, primary cultures of rat cortical cells, and larval zebrafish all express a fairly comprehensive transcriptome of TH signaling molecules, the spatiotemporal expression profiles as well as the responses to TH vary across species and developmental stages. The data presented here provides a roadmap for identifying appropriate in vitro and in simpler systems-based models for mechanistic studies and screening of chemicals that alter neurodevelopment via interference with TH action.
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Affiliation(s)
- Kyla M. Walter
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA, United States of America
| | - Katharina Dach
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
| | - Keri Hayakawa
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA, United States of America
| | - Susanne Giersiefer
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
| | - Heike Heuer
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
- Dept. Endocrinology, University Hospital Essen, Essen, Germany
| | - Pamela J. Lein
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA, United States of America
- * E-mail: (PJL); (EF)
| | - Ellen Fritsche
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
- * E-mail: (PJL); (EF)
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19
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Fritsche E, Barenys M, Klose J, Masjosthusmann S, Nimtz L, Schmuck M, Wuttke S, Tigges J. Development of the Concept for Stem Cell-Based Developmental Neurotoxicity Evaluation. Toxicol Sci 2019; 165:14-20. [PMID: 29982725 DOI: 10.1093/toxsci/kfy175] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Human brain development consists of a series of complex spatiotemporal processes that if disturbed by chemical exposure causes irreversible impairments of the nervous system. To evaluate a chemical disturbance in an alternative assay, the concept evolved that the complex procedure of brain development can be disassembled into several neurodevelopmental endpoints which can be represented by a combination of different alternative assays. In this review article, we provide a scientific rationale for the neurodevelopmental endpoints that are currently chosen to establish assays with human stem/and progenitor cells. Assays covering these major neurodevelopmental endpoints are thought to assemble as building blocks of a DNT testing battery.
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Affiliation(s)
- Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany.,Heinrich Heine University, 40225 Düsseldorf, Germany
| | | | - Jördis Klose
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Stefan Masjosthusmann
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Laura Nimtz
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Martin Schmuck
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Saskia Wuttke
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Julia Tigges
- IUF - Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
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20
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Vancamp P, Darras VM. From zebrafish to human: A comparative approach to elucidate the role of the thyroid hormone transporter MCT8 during brain development. Gen Comp Endocrinol 2018; 265:219-229. [PMID: 29183795 DOI: 10.1016/j.ygcen.2017.11.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/24/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023]
Abstract
Monocarboxylate transporter 8 (MCT8) facilitates transmembrane transport of thyroid hormones (THs) ensuring their action on gene expression during vertebrate neurodevelopment. A loss of MCT8 in humans results in severe psychomotor deficits associated with the Allan-Herndon-Dudley Syndrome (AHDS). However, where and when exactly a lack of MCT8 causes the neurological manifestations remains unclear because of the varying expression pattern of MCT8 between specific brain regions and cells. Here, we elaborate on the animal models that have been generated to elucidate the mechanisms underlying MCT8-deficient brain development. The absence of a clear neurological phenotype in Mct8 knockout mice made it clear that a single species would not suffice. The evolutionary conservation of TH action on neurodevelopment as well as the components regulating TH signalling however offers the opportunity to answer different aspects of MCT8 function in brain development using different vertebrate species. Moreover, the plethora of tools for genome editing available today facilitates gene silencing in these animals as well. Studies in the recently generated mct8-deficient zebrafish and Mct8/Oatp1c1 double knockout mice have put forward the current paradigm of impaired TH uptake at the level of the blood-brain barrier during peri- and postnatal development as being the main pathophysiological mechanism of AHDS. RNAi vector-based, cell-specific induction of MCT8 knockdown in the chicken embryo points to an additional function of MCT8 at the level of the neural progenitors during early brain development. Future studies including also additional in vivo models like Xenopus or in vitro approaches such as induced pluripotent stem cells will continue to help unravelling the exact role of MCT8 in developmental events. In the end, this multispecies approach will lead to a unifying thesis regarding the cellular and molecular mechanisms responsible for the neurological phenotype in AHDS patients.
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Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000 Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000 Leuven, Belgium.
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21
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Bal-Price A, Hogberg HT, Crofton KM, Daneshian M, FitzGerald RE, Fritsche E, Heinonen T, Hougaard Bennekou S, Klima S, Piersma AH, Sachana M, Shafer TJ, Terron A, Monnet-Tschudi F, Viviani B, Waldmann T, Westerink RHS, Wilks MF, Witters H, Zurich MG, Leist M. Recommendation on test readiness criteria for new approach methods in toxicology: Exemplified for developmental neurotoxicity. ALTEX-ALTERNATIVES TO ANIMAL EXPERIMENTATION 2018; 35:306-352. [PMID: 29485663 DOI: 10.14573/altex.1712081] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/29/2018] [Indexed: 01/06/2023]
Abstract
Multiple non-animal-based test methods have never been formally validated. In order to use such new approach methods (NAMs) in a regulatory context, criteria to define their readiness are necessary. The field of developmental neurotoxicity (DNT) testing is used to exemplify the application of readiness criteria. The costs and number of untested chemicals are overwhelming for in vivo DNT testing. Thus, there is a need for inexpensive, high-throughput NAMs, to obtain initial information on potential hazards, and to allow prioritization for further testing. A background on the regulatory and scientific status of DNT testing is provided showing different types of test readiness levels, depending on the intended use of data from NAMs. Readiness criteria, compiled during a stakeholder workshop, uniting scientists from academia, industry and regulatory authorities are presented. An important step beyond the listing of criteria, was the suggestion for a preliminary scoring scheme. On this basis a (semi)-quantitative analysis process was assembled on test readiness of 17 NAMs with respect to various uses (e.g. prioritization/screening, risk assessment). The scoring results suggest that several assays are currently at high readiness levels. Therefore, suggestions are made on how DNT NAMs may be assembled into an integrated approach to testing and assessment (IATA). In parallel, the testing state in these assays was compiled for more than 1000 compounds. Finally, a vision is presented on how further NAM development may be guided by knowledge of signaling pathways necessary for brain development, DNT pathophysiology, and relevant adverse outcome pathways (AOP).
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Affiliation(s)
- Anna Bal-Price
- European Commission, Joint Research Centre (EC JRC), Ispra (VA), Italy
| | - Helena T Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
| | - Kevin M Crofton
- National Centre for Computational Toxicology, US EPA, RTP, Washington, NC, USA
| | - Mardas Daneshian
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Rex E FitzGerald
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine & Heinrich-Heine-University, Düsseldorf, Germany
| | - Tuula Heinonen
- Finnish Centre for Alternative Methods (FICAM), University of Tampere, Tampere, Finland
| | | | - Stefanie Klima
- In vitro Toxicology and Biomedicine, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Aldert H Piersma
- RIVM, National Institute for Public Health and the Environment, Bilthoven, and Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Magdalini Sachana
- Organisation for Economic Co-operation and Development (OECD), Paris, France
| | - Timothy J Shafer
- National Centre for Computational Toxicology, US EPA, RTP, Washington, NC, USA
| | | | - Florianne Monnet-Tschudi
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland.,Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Barbara Viviani
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Italy
| | - Tanja Waldmann
- In vitro Toxicology and Biomedicine, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Remco H S Westerink
- Neurotoxicology Research Group, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Martin F Wilks
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland
| | - Hilda Witters
- VITO, Flemish Institute for Technological Research, Unit Environmental Risk and Health, Mol, Belgium
| | - Marie-Gabrielle Zurich
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland.,Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Marcel Leist
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany.,In vitro Toxicology and Biomedicine, Department of Biology, University of Konstanz, Konstanz, Germany
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Vancamp P, Darras VM. Dissecting the role of regulators of thyroid hormone availability in early brain development: Merits and potential of the chicken embryo model. Mol Cell Endocrinol 2017; 459:71-78. [PMID: 28153797 DOI: 10.1016/j.mce.2017.01.045] [Citation(s) in RCA: 10] [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: 12/21/2016] [Revised: 01/24/2017] [Accepted: 01/26/2017] [Indexed: 10/20/2022]
Abstract
Thyroid hormones (THs) are important mediators of vertebrate central nervous system (CNS) development, thereby regulating the expression of a wide variety of genes by binding to nuclear TH receptors. TH transporters and deiodinases are both needed to ensure appropriate intracellular TH availability, but the precise function of each of these regulators and their coaction during brain development is only partially understood. Rodent knockout models already provided some crucial insights, but their in utero development severely hampers research regarding the role of TH regulators during early embryonic stages. The establishment of novel gain- and loss-of-function techniques has boosted the position of externally developing non-mammalian vertebrates as research models in developmental endocrinology. Here, we elaborate on the chicken as a model organism to elucidate the function of TH regulators during embryonic CNS development. The fast-developing, relatively big and accessible embryo allows easy experimental manipulation, especially at early stages of brain development. Recent data on the characterisation and spatiotemporal expression pattern of different TH regulators in embryonic chicken CNS have provided the necessary background to dissect the function of each of them in more detail. We highlight some recent advances and important strategies to investigate the role of TH transporters and deiodinases in various CNS structures like the brain barriers, the cerebellum, the retina and the hypothalamus. Exploiting the advantages of this non-classical model can greatly contribute to complete our understanding of the regulation of TH bioavailability throughout embryonic CNS development.
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Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium.
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Dach K, Bendt F, Huebenthal U, Giersiefer S, Lein PJ, Heuer H, Fritsche E. BDE-99 impairs differentiation of human and mouse NPCs into the oligodendroglial lineage by species-specific modes of action. Sci Rep 2017; 7:44861. [PMID: 28317842 PMCID: PMC5357893 DOI: 10.1038/srep44861] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 02/15/2017] [Indexed: 01/02/2023] Open
Abstract
Polybrominated diphenyl ethers (PBDEs) are bioaccumulating flame retardants causing developmental neurotoxicity (DNT) in humans and rodents. Their DNT effects are suspected to involve thyroid hormone (TH) signaling disruption. Here, we tested the hypothesis whether disturbance of neural progenitor cell (NPC) differentiation into the oligodendrocyte lineage (O4+ cells) by BDE-99 involves disruption of TH action in human and mouse (h,m)NPCs. Therefore, we quantified differentiation of NPCs into O4+ cells and measured their maturation via expression of myelin-associated genes (hMBP, mMog) in presence and absence of TH and/or BDE-99. T3 promoted O4+ cell differentiation in mouse, but not hNPCs, and induced hMBP/mMog gene expression in both species. BDE-99 reduced generation of human and mouse O4+ cells, but there is no indication for BDE-99 interfering with cellular TH signaling during O4+ cell formation. BDE-99 reduced hMBP expression due to oligodendrocyte reduction, but concentrations that did not affect the number of mouse O4+ cells inhibited TH-induced mMog transcription by a yet unknown mechanism. In addition, ascorbic acid antagonized only the BDE-99-dependent loss of human, not mouse, O4+ cells by a mechanism probably independent of reactive oxygen species. These data point to species-specific modes of action of BDE-99 on h/mNPC development into the oligodendrocyte lineage.
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Affiliation(s)
- Katharina Dach
- IUF- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Farina Bendt
- IUF- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Ulrike Huebenthal
- IUF- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Susanne Giersiefer
- IUF- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California 95616, United States
| | - Heike Heuer
- IUF- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Ellen Fritsche
- IUF- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
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Abstract
Transport of thyroid hormone (TH) across the plasma membrane is essential for intracellular TH metabolism and action, and this is mediated by specific transporter proteins. During the last two decades several transporters capable of transporting TH have been identified, including monocarboxylate transporter 8 (MCT8), MCT10 and organic anion transporting polypeptide 1C1 (OATP1C1). In particular MCT8 and OATP1C1 are important for the regulation of local TH activity in the brain and thus for brain development. MCT8 is a protein containing 12 transmembrane domains, and is encoded by the SLC16A2 gene located on the X chromosome. It facilitates both TH uptake and efflux across the cell membrane. Male subjects with hemizygous mutations in MCT8 are afflicted with severe intellectual and motor disability, also known as the Allan-Herndon-Dudley syndrome (AHDS), which goes together with low serum T4 and high T3 levels. This review concerns molecular and clinical aspects of MCT8 function.
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Affiliation(s)
- Stefan Groeneweg
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - W Edward Visser
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Theo J Visser
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
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Shimojima K, Maruyama K, Kikuchi M, Imai A, Inoue K, Yamamoto T. Novel SLC16A2 mutations in patients with Allan-Herndon-Dudley syndrome. Intractable Rare Dis Res 2016; 5:214-7. [PMID: 27672545 PMCID: PMC4995413 DOI: 10.5582/irdr.2016.01051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Allan-Herndon-Dudley syndrome (AHDS) is an X-linked disorder caused by impaired thyroid hormone transporter. Patients with AHDS usually exhibit severe motor developmental delay, delayed myelination of the brain white matter, and elevated T3 levels in thyroid tests. Neurological examination of two patients with neurodevelopmental delay revealed generalized hypotonia, and not paresis, as the main neurological finding. Nystagmus and dyskinesia were not observed. Brain magnetic resonance imaging demonstrated delayed myelination in early childhood in both patients. Nevertheless, matured myelination was observed at 6 years of age in one patient. Although the key finding for AHDS is elevated free T3, one of the patients showed a normal T3 level in childhood, misleading the diagnosis of AHDS. Genetic analysis revealed two novel SLC16A2 mutations, p.(Gly122Val) and p.(Gly221Ser), confirming the AHDS diagnosis. These results indicate that AHDS diagnosis is sometimes challenging owing to clinical variability among patients.
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Affiliation(s)
- Keiko Shimojima
- Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan
| | - Koichi Maruyama
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Kasugai, Japan
| | - Masahiro Kikuchi
- Department of Pediatrics, Hitachi General Hospital, Hitachi, Japan
| | - Ayako Imai
- Department of Pediatrics, Hitachi General Hospital, Hitachi, Japan
| | - Ken Inoue
- National Institute of Neuroscience, National Center for Neurology and Psychiatry, Kodaira, Japan
| | - Toshiyuki Yamamoto
- Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan
- Address correspondence to: Dr. Toshiyuki Yamamoto, Tokyo Women's Medical University Institute for Integrated Medical Sciences, 8-1 Kawada-cho, Shinjuku-ward, Tokyo 162-8666, Japan. E-mail:
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Lee JY, Petratos S. Thyroid Hormone Signaling in Oligodendrocytes: from Extracellular Transport to Intracellular Signal. Mol Neurobiol 2016; 53:6568-6583. [PMID: 27427390 DOI: 10.1007/s12035-016-0013-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/10/2016] [Indexed: 01/24/2023]
Abstract
Thyroid hormone plays an important role in central nervous system (CNS) development, including the myelination of variable axonal calibers. It is well-established that thyroid hormone is required for the terminal differentiation of oligodendrocyte precursor cells (OPCs) into myelinating oligodendrocytes by inducing rapid cell-cycle arrest and constant transcription of pro-differentiation genes. This is well supported by the hypomyelinating phenotypes exhibited by patients with congenital hypothyroidism, cretinism. During development, myelinating oligodendrocytes only appear after the formation of neural circuits, indicating that the timing of oligodendrocyte differentiation is important. Since fetal and post-natal serum thyroid hormone levels peak at the stage of active myelination, it is suspected that the timing of oligodendrocyte development is finely controlled by thyroid hormone. The essential machinery for thyroid hormone signaling such as deiodinase activity (utilized by cells to auto-regulate the level of thyroid hormone), and nuclear thyroid hormone receptors (for gene transcription) are expressed on oligodendrocytes. In this review, we discuss the known and potential thyroid hormone signaling pathways that may regulate oligodendrocyte development and CNS myelination. Moreover, we evaluate the potential of targeting thyroid hormone signaling for white matter injury or disease.
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Affiliation(s)
- Jae Young Lee
- Department of Medicine, Central Clinical School, Monash University, Prahran, Victoria, 3004, Australia.,ToolGen, Inc., #1204, Byucksan Digital Valley 6-cha, Seoul, South Korea
| | - Steven Petratos
- Department of Medicine, Central Clinical School, Monash University, Prahran, Victoria, 3004, Australia.
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Ono E, Ariga M, Oshima S, Hayakawa M, Imai M, Ochiai Y, Mochizuki H, Namba N, Ozono K, Miyata I. Three novel mutations of the MCT8 (SLC16A2) gene: individual and temporal variations of endocrinological and radiological features. Clin Pediatr Endocrinol 2016; 25:23-35. [PMID: 27212794 PMCID: PMC4860513 DOI: 10.1297/cpe.25.23] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/17/2015] [Indexed: 11/13/2022] Open
Abstract
We performed genetic analysis and clinical investigations for three patients with
suspected monocarboxylate transporter 8 (MCT8) deficiency. On genetic analysis of the
MCT8(SLC16A2) gene, novel mutations (c.1333C>A;
p.R445S, c.587G>A; p.G196E and c.1063_1064insCTACC; p.R355PfsX64) were identified in
each of three patients. Although thyroid function tests (TFTs) showed the typical pattern
of MCT8 deficiency at the time of genetic diagnosis in all patients, two patients
occasionally were euthyroid. A TRH test revealed low response, exaggerated response and
normal response of TSH, respectively. Endocrinological studies showed gonadotropin (Gn)
deficiency in two adult patients. On ultrasonography, goiter was detected in one patient.
Interestingly, pituitary magnetic resonance imaging (MRI) demonstrated atrophy and
thinness of the pituitary gland in two patients. Our findings suggest that thyroid status
in patients with MCT8 deficiency varies with time of examination, and repeated TFTs are
necessary for patients suspected of MCT8 deficiency before genetic analysis. In addition,
it is noteworthy that some variations were observed on the TRH test and ultrasonography of
the thyroid gland in the present study. Morphological abnormality of the pituitary gland
may be found in some patients, while Gn deficiency should be considered as one of the
complications.
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Affiliation(s)
- Erina Ono
- Department of Pediatrics, The Jikei University School of Medicine, Tokyo, Japan; Department of Pediatrics, Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled, Tokyo, Japan
| | - Masamichi Ariga
- Department of Pediatrics, Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled, Tokyo, Japan
| | - Sakiko Oshima
- Department of Pediatrics, Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled, Tokyo, Japan
| | - Mika Hayakawa
- Department of Pediatrics, Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled, Tokyo, Japan
| | - Masayuki Imai
- Department of Pediatrics, Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled, Tokyo, Japan
| | - Yukikatsu Ochiai
- Department of Pediatrics, Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled, Tokyo, Japan
| | - Hiroshi Mochizuki
- Department of Endocrinology and Metabolism, Saitama Children's Medical Center, Saitama, Japan
| | - Noriyuki Namba
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Ichiro Miyata
- Department of Pediatrics, The Jikei University School of Medicine, Tokyo, Japan
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Kim JH, Kim YM, Yum MS, Choi JH, Lee BH, Kim GH, Yoo HW. Clinical and endocrine features of two Allan-Herndon-Dudley syndrome patients with monocarboxylate transporter 8 mutations. Horm Res Paediatr 2016; 83:288-92. [PMID: 25896225 DOI: 10.1159/000371466] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/09/2014] [Indexed: 11/19/2022] Open
Abstract
The monocarboxylate transporter 8 (MCT8) gene, located on chromosome Xq13.2, encodes a thyroid hormone transporter that is involved in triiodothyronine (T3) uptake into central neurons. MCT8 mutations cause an X-linked syndromic disorder known as Allan-Herndon-Dudley syndrome (AHDS) that is characterized by severe psychomotor delays, abnormal thyroid function, and hypomyelinated leukodystrophies. We identified 2 AHDS patients with developmental delays, truncal hypotonia, and spastic paraplegia. These patients presented with psychomotor retardation and characteristic thyroid function abnormalities, such as elevated T3 and low T4 levels. Direct MCT8 sequencing identified heterozygous mutations in each patient: p.I114N and p.A224V, respectively. Because it is difficult to suspect AHDS solely according to neurological features, thyroid function, including the T3 level, should be screened in male patients with X-linked mental retardation. Although the clinical features of hypothyroidism cannot be improved by only administering levothyroxine treatment, early diagnosis, management, and appropriate genetic counseling should be provided to at-risk families.
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Affiliation(s)
- Ja Hye Kim
- Division of Pediatric Endocrinology and Metabolism, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
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Matheus MG, Lehman RK, Bonilha L, Holden KR. Redefining the Pediatric Phenotype of X-Linked Monocarboxylate Transporter 8 (MCT8) Deficiency: Implications for Diagnosis and Therapies. J Child Neurol 2015; 30:1664-8. [PMID: 25900139 DOI: 10.1177/0883073815578524] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/18/2015] [Indexed: 12/20/2022]
Abstract
X-linked monocarboxylate transporter 8 (MCT8) deficiency results from a loss-of-function mutation in the monocarboxylate transporter 8 gene, located on chromosome Xq13.2 (Allan-Herndon-Dudley syndrome). Affected boys present early in life with neurodevelopment delays but have pleasant dispositions and commonly have elevated serum triiodothyronine. They also have marked axial hypotonia and quadriparesis but surprisingly little spasticity early in their disease course. They do, however, have subtle involuntary movements, most often dystonia. The combination of hypotonia and dystonia presents a neurorehabilitation challenge and explains why spasticity-directed therapies have commonly produced suboptimal responses. Our aim was to better define the spectrum of motor disability and to elucidate the neuroanatomic basis of the motor impairments seen in MCT8 deficiency using clinical observation and brain magnetic resonance imaging (MRI) in a cohort of 6 affected pediatric patients. Our findings identified potential imaging biomarkers and suggest that rehabilitation efforts targeting dystonia may be more beneficial than those targeting spasticity in the prepubertal pediatric MCT8 deficiency population.
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Affiliation(s)
- Maria Gisele Matheus
- Department of Radiology and Radiological Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Rebecca K Lehman
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA Department of Neurology, Medical University of South Carolina, Charleston, SC, USA
| | - Leonardo Bonilha
- Department of Neurology, Medical University of South Carolina, Charleston, SC, USA
| | - Kenton R Holden
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA Department of Neurology, Medical University of South Carolina, Charleston, SC, USA Greenwood Genetic Center, Greenwood, SC, USA
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31
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Armour CM, Kersseboom S, Yoon G, Visser TJ. Further Insights into the Allan-Herndon-Dudley Syndrome: Clinical and Functional Characterization of a Novel MCT8 Mutation. PLoS One 2015; 10:e0139343. [PMID: 26426690 PMCID: PMC4591285 DOI: 10.1371/journal.pone.0139343] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 09/11/2015] [Indexed: 11/23/2022] Open
Abstract
Background Mutations in the thyroid hormone (TH) transporter MCT8 have been identified as the cause for Allan-Herndon-Dudley Syndrome (AHDS), characterized by severe psychomotor retardation and altered TH serum levels. Here we report a novel MCT8 mutation identified in 4 generations of one family, and its functional characterization. Methods Proband and family members were screened for 60 genes involved in X-linked cognitive impairment and the MCT8 mutation was confirmed. Functional consequences of MCT8 mutations were studied by analysis of [125I]TH transport in fibroblasts and transiently transfected JEG3 and COS1 cells, and by subcellular localization of the transporter. Results The proband and a male cousin demonstrated clinical findings characteristic of AHDS. Serum analysis showed high T3, low rT3, and normal T4 and TSH levels in the proband. A MCT8 mutation (c.869C>T; p.S290F) was identified in the proband, his cousin, and several female carriers. Functional analysis of the S290F mutant showed decreased TH transport, metabolism and protein expression in the three cell types, whereas the S290A mutation had no effect. Interestingly, both uptake and efflux of T3 and T4 was impaired in fibroblasts of the proband, compared to his healthy brother. However, no effect of the S290F mutation was observed on TH efflux from COS1 and JEG3 cells. Immunocytochemistry showed plasma membrane localization of wild-type MCT8 and the S290A and S290F mutants in JEG3 cells. Conclusions We describe a novel MCT8 mutation (S290F) in 4 generations of a family with Allan-Herndon-Dudley Syndrome. Functional analysis demonstrates loss-of-function of the MCT8 transporter. Furthermore, our results indicate that the function of the S290F mutant is dependent on cell context. Comparison of the S290F and S290A mutants indicates that it is not the loss of Ser but its substitution with Phe, which leads to S290F dysfunction.
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Affiliation(s)
- Christine M. Armour
- Regional Genetics Program, Children’s Hospital of Eastern Ontario, and Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - Simone Kersseboom
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Grace Yoon
- Department of Paediatrics, Divisions of Neurology and Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Canada
| | - Theo J. Visser
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- * E-mail:
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32
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La Piana R, Vanasse M, Brais B, Bernard G. Myelination Delay and Allan-Herndon-Dudley Syndrome Caused by a Novel Mutation in the SLC16A2 Gene. J Child Neurol 2015; 30:1371-4. [PMID: 25380603 DOI: 10.1177/0883073814555189] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 09/19/2014] [Indexed: 11/16/2022]
Abstract
Allan-Herndon-Dudley syndrome is an X-linked disease caused by mutations in the solute carrier family 16 member 2 (SLC16A2) gene. As SLC16A2 encodes the monocarboxylate transporter 8 (MCT8), a thyroid hormone transporter, patients with Allan-Herndon-Dudley syndrome present a specific altered thyroid hormone profile. Allan-Herndon-Dudley syndrome has been associated with myelination delay on the brain magnetic resonance imaging (MRI) of affected subjects. We report a patient with Allan-Herndon-Dudley syndrome characterized by developmental delay, hypotonia, and delayed myelination caused by a novel SLC16A2 mutation (p.L291R). The thyroid hormones profile in our patient was atypical for Allan-Herndon-Dudley syndrome. The follow-up examinations showed that the progression of the myelination was not accompanied by a clinical improvement. Our paper suggests that SLC16A2 mutations should be investigated in patients with myelination delay even when the thyroid function is not conclusively altered.
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Affiliation(s)
- Roberta La Piana
- Laboratory of Neurogenetics of Movement, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada Department of Neuroradiology, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Michel Vanasse
- Department of Neuroscience, Division of Neurology, CHU-Sainte-Justine, Montreal, Canada
| | - Bernard Brais
- Laboratory of Neurogenetics of Movement, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada Departments of Neurology, Neurosurgery and Human Genetics, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Genevieve Bernard
- Department of Neuroscience, Division of Neurology, CHU-Sainte-Justine, Montreal, Canada Departments of Pediatrics, Neurology and Neurosurgery, division of Pediatric Neurology, Montreal Children's Hospital, Montreal, Canada
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Leach EL, Shevell M, Bowden K, Stockler-Ipsiroglu S, van Karnebeek CDM. Treatable inborn errors of metabolism presenting as cerebral palsy mimics: systematic literature review. Orphanet J Rare Dis 2014; 9:197. [PMID: 25433678 PMCID: PMC4273454 DOI: 10.1186/s13023-014-0197-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 11/17/2014] [Indexed: 01/23/2023] Open
Abstract
Background Inborn errors of metabolism (IEMs) have been anecdotally reported in the literature as presenting with features of cerebral palsy (CP) or misdiagnosed as ‘atypical CP’. A significant proportion is amenable to treatment either directly targeting the underlying pathophysiology (often with improvement of symptoms) or with the potential to halt disease progression and prevent/minimize further damage. Methods We performed a systematic literature review to identify all reports of IEMs presenting with CP-like symptoms before 5 years of age, and selected those for which evidence for effective treatment exists. Results We identified 54 treatable IEMs reported to mimic CP, belonging to 13 different biochemical categories. A further 13 treatable IEMs were included, which can present with CP-like symptoms according to expert opinion, but for which no reports in the literature were identified. For 26 of these IEMs, a treatment is available that targets the primary underlying pathophysiology (e.g. neurotransmitter supplements), and for the remainder (n = 41) treatment exerts stabilizing/preventative effects (e.g. emergency regimen). The total number of treatments is 50, and evidence varies for the various treatments from Level 1b, c (n = 2); Level 2a, b, c (n = 16); Level 4 (n = 35); to Level 4–5 (n = 6); Level 5 (n = 8). Thirty-eight (57%) of the treatable IEMs mimicking CP can be identified by ready available metabolic screening tests in blood or urine, while the remaining IEMs require more specific and sometimes invasive tests. Conclusions Limited by the rare nature of IEMs and incomplete information in the literature, we conclude that (1) A surprisingly large number of IEMs can present with CP symptoms, as ‘CP mimics’, (2) although individually rare, a large proportion of these diseases are treatable such that neurological damage can either be reversed or prevented, (3) clinician awareness of treatable CP mimics is important for appropriate screening, diagnosis, and early intervention, and (4) systematic studies are required to elucidate the collective frequency of treatable IEMs in CP. Electronic supplementary material The online version of this article (doi:10.1186/s13023-014-0197-2) contains supplementary material, which is available to authorized users.
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Rodrigues F, Grenha J, Ortez C, Nascimento A, Morte B, M-Belinchón M, Armstrong J, Colomer J. Hypotonic male infant and MCT8 deficiency - a diagnosis to think about. BMC Pediatr 2014; 14:252. [PMID: 25284458 PMCID: PMC4287395 DOI: 10.1186/1471-2431-14-252] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 10/01/2014] [Indexed: 11/17/2022] Open
Abstract
Background Thyroid hormone is crucial in the development of different organs, particularly the brain. MCT8 is a specific transporter of triiodothyronine (T3) hormone and MCT8 gene mutations cause a rare X-linked disorder named MCT8 deficiency, also known as Allan-Herndon-Dudley syndrome, characterized by psychomotor retardation and hypotonia. Typically, elevation of T3 and delayed myelination in cerebral magnetic resonance imaging are found. Case presentation We present a 24-month-old boy, born from non-consanguineous healthy parents, with severe motor and cognitive delay and global hypotonia, being unable to hold head upright or sit without support. Deep tendon reflexes were absent bilaterally at the ankles. T3 was elevated and thyroxine slightly decreased, consistent with MCT8 deficiency. Genetic studies confirmed the diagnosis. Conclusions Although a rare disease (MCT8 mutations have been reported in about 50 families all around the world), we illustrate the importance of excluding Allan-Herndon-Dudley syndrome in the evaluation of floppy male infants with development delay, without history of perinatal asphyxia. The simple evaluation of thyroid status, including T3, T4 and TSH can guide the diagnosis, avoiding a number of useless, expensive and invasive investigations and allowing appropriate genetic counseling to the affected families.
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Affiliation(s)
- Filipa Rodrigues
- Neuromuscular Unit, Neurology Department, Fundación Sant Joan de Déu, Hospital Materno-Infantil Sant Joan de Déu, Passeig Sant Joan de Déu, 2, 08950 Esplugues de Llobregat, Barcelona, Spain.
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Zada D, Tovin A, Lerer-Goldshtein T, Vatine GD, Appelbaum L. Altered behavioral performance and live imaging of circuit-specific neural deficiencies in a zebrafish model for psychomotor retardation. PLoS Genet 2014; 10:e1004615. [PMID: 25255244 PMCID: PMC4177677 DOI: 10.1371/journal.pgen.1004615] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 07/18/2014] [Indexed: 11/28/2022] Open
Abstract
The mechanisms and treatment of psychomotor retardation, which includes motor and cognitive impairment, are indefinite. The Allan-Herndon-Dudley syndrome (AHDS) is an X-linked psychomotor retardation characterized by delayed development, severe intellectual disability, muscle hypotonia, and spastic paraplegia, in combination with disturbed thyroid hormone (TH) parameters. AHDS has been associated with mutations in the monocarboxylate transporter 8 (mct8/slc16a2) gene, which is a TH transporter. In order to determine the pathophysiological mechanisms of AHDS, MCT8 knockout mice were intensively studied. Although these mice faithfully replicated the abnormal serum TH levels, they failed to exhibit the neurological and behavioral symptoms of AHDS patients. Here, we generated an mct8 mutant (mct8−/−) zebrafish using zinc-finger nuclease (ZFN)-mediated targeted gene editing system. The elimination of MCT8 decreased the expression levels of TH receptors; however, it did not affect the expression of other TH-related genes. Similar to human patients, mct8−/− larvae exhibited neurological and behavioral deficiencies. High-throughput behavioral assays demonstrated that mct8−/− larvae exhibited reduced locomotor activity, altered response to external light and dark transitions and an increase in sleep time. These deficiencies in behavioral performance were associated with altered expression of myelin-related genes and neuron-specific deficiencies in circuit formation. Time-lapse imaging of single-axon arbors and synapses in live mct8−/− larvae revealed a reduction in filopodia dynamics and axon branching in sensory neurons and decreased synaptic density in motor neurons. These phenotypes enable assessment of the therapeutic potential of three TH analogs that can enter the cells in the absence of MCT8. The TH analogs restored the myelin and axon outgrowth deficiencies in mct8−/− larvae. These findings suggest a mechanism by which MCT8 regulates neural circuit assembly, ultimately mediating sensory and motor control of behavioral performance. We also propose that the administration of TH analogs early during embryo development can specifically reduce neurological damage in AHDS patients. In a wide range of brain disorders, mutations in specific genes cause alterations in the development and function of neural circuits that ultimately affect behavior. A major challenge is to uncover the mechanism and provide treatment which is capable of preventing brain damage. Allan-Herndon-Dudley syndrome (AHDS) is a severe psychomotor retardation characterized by intellectual disabilities, neurological impairment and abnormal thyroid hormone (TH) levels. Mutations in the TH transporter MCT8 are associated with AHDS. Mice that lack the MCT8 protein exhibited impaired TH levels, as is the case in human patients; however, they lack neurological defects. Here, we generated an mct8 mutant (mct8−/−) zebrafish, which exhibited neurological and behavioral deficiencies and mimics pathological conditions of AHDS patients. The zebrafish is a simple transparent vertebrate and its nervous system is conserved with mammals. Time-lapse live imaging of single axons and synapses, and video-tracking of behavior revealed deficiencies in neural circuit assembly, which are associated with disturbed sleep and altered locomotor activity. In addition, since the mct8−/− larvae provides a highthroughput platform for testing therapeutic drugs, we showed that TH analogs can recover neurological deficiencies in an animal model for psychomotor retardation.
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Affiliation(s)
- David Zada
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Adi Tovin
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Tali Lerer-Goldshtein
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Gad David Vatine
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Lior Appelbaum
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
- * E-mail:
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Azzolini S, Nosadini M, Balzarin M, Sartori S, Suppiej A, Mardari R, Greggio NA, Toldo I. Delayed myelination is not a constant feature of Allan-Herndon-Dudley syndrome: report of a new case and review of the literature. Brain Dev 2014; 36:716-20. [PMID: 24268987 DOI: 10.1016/j.braindev.2013.10.009] [Citation(s) in RCA: 18] [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] [Received: 08/05/2013] [Revised: 10/20/2013] [Accepted: 10/21/2013] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Allan-Herndon-Dudley syndrome is an X-linked condition caused by mutations of the monocarboxylate transporter 8 gene. This syndrome is characterized by axial hypotonia, severe mental retardation, dysarthria, athetoid movements, spastic paraplegia, and a typical thyroid hormone profile. In most of the cases reported so far, brain magnetic resonance imaging showed delayed myelination of the central white matter and this finding greatly affects the diagnosis of the syndrome. CASE REPORT We present a new case studied with magnetic resonance imaging and spectroscopy and we reviewed all the articles published between 2004 and 2012 containing information on brain neuroimaging in this syndrome. An Italian boy, showing a classical phenotype of the syndrome, was diagnosed at 17months of age. Genetic analysis revealed a new frameshift mutation of the monocarboxylate transporter 8 gene. His brain magnetic resonance imaging and spectroscopy, performed at the age of 14months, were normal. DISCUSSION Among the 33 cases reported in the literature, 3 cases had normal neuroimaging and in 7 of 14 cases, having a longitudinal follow-up, the initial finding of delayed myelination gradually improved. Our case and the review of the pertinent literature suggest that Allan-Herndon-Dudley syndrome should be suspected in males with the typical neurological and thyroid profile, even in cases with normal brain myelination.
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Affiliation(s)
- Sara Azzolini
- Pediatric Endocrinology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy
| | - Margherita Nosadini
- Child Neurology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy
| | - Marta Balzarin
- Pediatric Endocrinology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy
| | - Stefano Sartori
- Child Neurology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy
| | - Agnese Suppiej
- Child Neurology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy
| | - Rodica Mardari
- Institute of Neuroradiology, University Hospital of Padua, Padua, Italy
| | - Nella Augusta Greggio
- Pediatric Endocrinology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy
| | - Irene Toldo
- Child Neurology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Padua, Italy.
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Kurian MA, Jungbluth H. Genetic disorders of thyroid metabolism and brain development. Dev Med Child Neurol 2014; 56:627-34. [PMID: 24665922 PMCID: PMC4231219 DOI: 10.1111/dmcn.12445] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/13/2014] [Indexed: 01/28/2023]
Abstract
Normal thyroid metabolism is essential for human development, including the formation and functioning of the central and peripheral nervous system. Disorders of thyroid metabolism are increasingly recognized within the spectrum of paediatric neurological disorders. Both hypothyroid and hyperthyroid disease states (resulting from genetic and acquired aetiologies) can lead to characteristic neurological syndromes, with cognitive delay, extrapyramidal movement disorders, neuropsychiatric symptoms, and neuromuscular manifestations. In this review, the neurological manifestations of genetic disorders of thyroid metabolism are outlined, with particular focus on Allan-Herndon-Dudley syndrome and benign hereditary chorea. We report in detail the clinical features, major neurological and neuropsychiatric manifestations, molecular genetic findings, disease mechanisms, and therapeutic strategies for these emerging genetic 'brain-thyroid' disorders.
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Affiliation(s)
- Manju A Kurian
- Developmental Neurosciences, UCL-Institute of Child HealthLondon, UK,Department of Neurology, Great Ormond Street Hospital for ChildrenLondon, UK,Correspondence to Manju Kurian, Institute of Child Health, Level 1 CMGU Room 111, 30 Guilford Street, London WC1N 1EH, UK. E-mail:
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation TrustLondon, UK,Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College LondonLondon, UK,Clinical Neuroscience Division, Institute of Psychiatry, King's College LondonLondon, UK
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Fu J, Refetoff S, Dumitrescu AM. Inherited defects of thyroid hormone-cell-membrane transport: review of recent findings. Curr Opin Endocrinol Diabetes Obes 2013; 20:434-40. [PMID: 23974772 PMCID: PMC4061907 DOI: 10.1097/01.med.0000432531.03233.ad] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW This review summarizes the most significant findings over the last year regarding human and animal models deficient in thyroid hormone cell-membrane transporters (THCMTs). Although several THCMTs have been modelled in genetically engineered mice, the only THCMT defect known in humans is that caused by mutations in the monocarboxylate transporter 8 (MCT8) gene. RECENT FINDINGS The importance of several amino acid residues has been assessed in vitro to further our understanding on the structure-function of the MCT8. The administration of the thyromimetic compound, diiodothyropropionic acid, has been tested in patients with MCT8 gene mutations, following studies of its use in mice. Another thyroid hormone analogue, 3,3',5,5'-tetraiodothyroacetic acid, was tested in Mct8-deficient mice. The phenotypes of L-type aminoacid transporter 2 and organic anion transporting polypeptide 1C1 deficiencies have been studied in mouse models. Mct8/organic anion transporting polypeptide 1C1 double knockout mice have been shown to manifest neurodevelopmental deficits. Zebrafish is emerging as another vertebrate model that may be useful to study the role of Mct8 in brain development. SUMMARY Studies on the pathogenesis and therapy of MCT8 deficiency are in progress, and new vertebrate models that are suitable to study the neurological consequences of the syndrome are being explored.
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Affiliation(s)
- Jiao Fu
- Department of Medicine, The University of Chicago, Chicago, Illinois, USA
| | - Samuel Refetoff
- Departments of Medicine, Pediatrics and Genetics, The University of Chicago, Chicago, Illinois, USA
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Vijay N, Morris ME. Role of monocarboxylate transporters in drug delivery to the brain. Curr Pharm Des 2013; 20:1487-98. [PMID: 23789956 DOI: 10.2174/13816128113199990462] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/18/2013] [Indexed: 02/08/2023]
Abstract
Monocarboxylate transporters (MCTs) are known to mediate the transport of short chain monocarboxylates such as lactate, pyruvate and butyrate. Currently, fourteen members of this transporter family have been identified by sequence homology, of which only the first four members (MCT1- MCT4) have been shown to mediate the proton-linked transport of monocarboxylates. Another transporter family involved in the transport of endogenous monocarboxylates is the sodium coupled MCTs (SMCTs). These act as a symporter and are dependent on a sodium gradient for their functional activity. MCT1 is the predominant transporter among the MCT isoforms and is present in almost all tissues including kidney, intestine, liver, heart, skeletal muscle and brain. The various isoforms differ in terms of their substrate specificity and tissue localization. Due to the expression of these transporters in the kidney, intestine, and brain, they may play an important role in influencing drug disposition. Apart from endogenous short chain monocarboxylates, they also mediate the transport of exogenous drugs such as salicylic acid, valproic acid, and simvastatin acid. The influence of MCTs on drug pharmacokinetics has been extensively studied for γ-hydroxybutyrate (GHB) including distribution of this drug of abuse into the brain and the results will be summarized in this review. The physiological role of these transporters in the brain and their specific cellular localization within the brain will also be discussed. This review will also focus on utilization of MCTs as potential targets for drug delivery into the brain including their role in the treatment of malignant brain tumors.
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Vatine GD, Zada D, Lerer-Goldshtein T, Tovin A, Malkinson G, Yaniv K, Appelbaum L. Zebrafish as a model for monocarboxyl transporter 8-deficiency. J Biol Chem 2012; 288:169-80. [PMID: 23161551 DOI: 10.1074/jbc.m112.413831] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Allan-Herndon-Dudley syndrome (AHDS) is a severe psychomotor retardation characterized by neurological impairment and abnormal thyroid hormone (TH) levels. Mutations in the TH transporter, monocarboxylate transporter 8 (MCT8), are associated with AHDS. MCT8 knock-out mice exhibit impaired TH levels; however, they lack neurological defects. Here, the zebrafish mct8 gene and promoter were isolated, and mct8 promoter-driven transgenic lines were used to show that, similar to humans, mct8 is primarily expressed in the nervous and vascular systems. Morpholino-based knockdown and rescue experiments revealed that MCT8 is strictly required for neural development in the brain and spinal cord. This study shows that MCT8 is a crucial regulator during embryonic development and establishes the first vertebrate model for MCT8 deficiency that exhibits a neurological phenotype.
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Affiliation(s)
- Gad David Vatine
- Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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