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Sawant H, Selvaraj R, Manogaran P, Borthakur A. Intestinal Epithelial Creatine Transporter SLC6A8 Dysregulation in Inflammation and in Response to Adherent Invasive E. coli Infection. Int J Mol Sci 2024; 25:6537. [PMID: 38928243 PMCID: PMC11204174 DOI: 10.3390/ijms25126537] [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: 05/27/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Creatine transporter (CrT1) mediates cellular uptake of creatine (Cr), a nutrient pivotal in maintaining energy homeostasis in various tissues including intestinal epithelial cells (IECs). The impact of CrT1 deficiency on the pathogenesis of various psychiatric and neurological disorders has been extensively investigated. However, there are no studies on its regulation in IECs in health and disease. Current studies have determined differential expression of CrT1 along the length of the mammalian intestine and its dysregulation in inflammatory bowel disease (IBD)-associated inflammation and Adherent Invasive E. coli (AIEC) infection. CrT1 mRNA and protein levels in normal intestines and their alterations in inflammation and following AIEC infection were determined in vitro in model IECs (Caco-2/IEC-6) and in vivo in SAMP1/YitFc mice, a model of spontaneous ileitis resembling human IBD. CrT1 is differentially expressed in different regions of mammalian intestines with its highest expression in jejunum. In vitro, CrT1 function (Na+-dependent 14C-Cr uptake), expression and promoter activity significantly decreased following TNFα/IL1β treatments and AIEC infection. SAMP1 mice and ileal organoids generated from SAMP1 mice also showed decreased CrT1 mRNA and protein compared to AKR controls. Our studies suggest that Cr deficiency in IECs secondary to CrT1 dysregulation could be a key factor contributing to IBD pathogenesis.
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Affiliation(s)
| | | | | | - Alip Borthakur
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA; (H.S.); (R.S.); (P.M.)
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Fernandes-Pires G, Azevedo MD, Lanzillo M, Roux-Petronelli C, Binz PA, Cudalbu C, Sandi C, Tenenbaum L, Braissant O. Rescue of myocytes and locomotion through AAV2/9-2YF intracisternal gene therapy in a rat model of creatine transporter deficiency. Mol Ther Methods Clin Dev 2024; 32:101251. [PMID: 38745894 PMCID: PMC11091509 DOI: 10.1016/j.omtm.2024.101251] [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: 11/01/2023] [Accepted: 04/18/2024] [Indexed: 05/16/2024]
Abstract
Creatine deficiency syndromes (CDS), caused by mutations in GATM (AGAT), GAMT, and SLC6A8, mainly affect the central nervous system (CNS). CDS show brain creatine (Cr) deficiency, intellectual disability with severe speech delay, behavioral troubles, epilepsy, and motor dysfunction. AGAT/GAMT-deficient patients lack brain Cr synthesis but express the Cr transporter SLC6A8 at the blood-brain barrier and are thus treatable by oral supplementation of Cr. In contrast, no satisfactory treatment has been identified for Cr transporter deficiency (CTD), the most frequent of CDS. We used our Slc6a8Y389C CTD rat model to develop a new AAV2/9-2YF-driven gene therapy re-establishing the functional Slc6a8 transporter in rat CNS. We show, after intra-cisterna magna AAV2/9-2YF-Slc6a8-FLAG vector injection of postnatal day 11 pups, the transduction of Slc6a8-FLAG in cerebellum, medulla oblongata, and spinal cord as well as a partial recovery of Cr in these brain regions, together with full prevention of locomotion defaults and impairment of myocyte development observed in Slc6a8Y389 C/y male rats. While more work is needed to correct those CTD phenotypes more associated with forebrain structures, this study is the first demonstrating positive effects of an AAV-driven gene therapy on CTD and thus represents a very encouraging approach to treat the so-far untreatable CTD.
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Affiliation(s)
- Gabriella Fernandes-Pires
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Marcelo Duarte Azevedo
- Laboratory of Cellular and Molecular Neurotherapies, Clinical Neurosciences Department, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Marc Lanzillo
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Clothilde Roux-Petronelli
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Pierre-Alain Binz
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Animal Imaging and Technology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Carmen Sandi
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Liliane Tenenbaum
- Laboratory of Cellular and Molecular Neurotherapies, Clinical Neurosciences Department, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
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Curie A, Lion-François L, Valayannopoulos V, Perreton N, Gavanon M, Touil N, Brun-Laurisse A, Gheurbi F, Buchy M, Halep H, Cheillan D, Mercier C, Brassier A, Desnous B, Kassai B, De Lonlay P, Des Portes V. Clinical Characteristics, Developmental Trajectory, and Caregiver Burden of Patients With Creatine Transporter Deficiency ( SLC6A8). Neurology 2024; 102:e209243. [PMID: 38531017 DOI: 10.1212/wnl.0000000000209243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 01/19/2024] [Indexed: 03/28/2024] Open
Abstract
BACKGROUND AND OBJECTIVES Creatine transporter deficiency (CTD) is a rare X-linked genetic disorder characterized by intellectual disability (ID). We evaluated the clinical characteristics and trajectory of patients with CTD and the impact of the disease on caregivers to identify relevant endpoints for future therapeutic trials. METHODS As part of a French National Research Program, patients with CTD were included based on (1) a pathogenic SLC6A8 variant and (2) ID and/or autism spectrum disorder. Families and patients were referred by the physician who ordered the genetic analysis through Reference Centers of ID from rare causes and inherited metabolic diseases. After we informed the patients and their parents/guardians about the study, all of them gave written consent and were included. A control group of age-matched and sex-matched patients with Fragile X syndrome was also included. Physical examination, neuropsychological assessments, and caregiver impact were assessed. All data were analyzed using R software. RESULTS Thirty-one patients (27 male, 4 female) were included (25/31 aged 18 years or younger). Most of the patients (71%) had symptoms at <24 months of age. The mean age at diagnosis was 6.5 years. Epilepsy occurred in 45% (mean age at onset: 8 years). Early-onset behavioral disorder occurred in 82%. Developmental trajectory was consistently delayed (fine and gross motor skills, language, and communication/sociability). Half of the patients with CTD had axial hypotonia during the first year of life. All patients were able to walk without help, but 7/31 had ataxia and only 14/31 could walk tandem gait. Most of them had abnormal fine motor skills (27/31), and most of them had language impairment (30/31), but 12/23 male patients (52.2%) completed the Peabody Picture Vocabulary Test. Approximately half (14/31) had slender build. Most of them needed nursing care (20/31), generally 1-4 h/d. Adaptive assessment (Vineland) confirmed that male patients with CTD had moderate-to-severe ID. Most caregivers (79%) were at risk of burnout, as shown by Caregiver Burden Inventory (CBI) > 36 (significantly higher than for patients with Fragile X syndrome) with a high burden of time dependence. DISCUSSION In addition to clinical endpoints, such as the assessment of epilepsy and the developmental trajectory of the patient, the Vineland scale, PPVT5, and CBI are of particular interest as outcome measures for future trials. TRIAL REGISTRATION INFORMATION ANSM Registration Number 2010-A00327-32.
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Affiliation(s)
- Aurore Curie
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Laurence Lion-François
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Vassili Valayannopoulos
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Nathalie Perreton
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Marie Gavanon
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Nathalie Touil
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Amandine Brun-Laurisse
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Fahra Gheurbi
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Marion Buchy
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Hulya Halep
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - David Cheillan
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Catherine Mercier
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Anaïs Brassier
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Béatrice Desnous
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Behrouz Kassai
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Pascale De Lonlay
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
| | - Vincent Des Portes
- From the Child Neurology Department and Reference Centre of Rare Disease with Intellectual Disability (A.C., L.L.-F., M.G., A.B.-L., F.G., M.B., V.D.P.), Hospices Civils de Lyon, Lyon University Hospital; Lyon Neuroscience Research Centre (A.C., M.G., A.B.-L., F.G., M.B., V.D.P.), CNRS UMR5292, INSERM U1028; Lyon University (A.C., V.D.P.); Reference Centre for Inherited Metabolic Diseases (V.V., A.B., P.D.L.), Imagine Institute, Necker Enfants-Malades Hospital, Paris University Hospital, University of Paris Descartes; Clinical Investigation Center 1407/INSERM-Hospices Civils de Lyon (N.P., N.T., H.H., B.K.), Bron; Inborn Errors of Metabolism Unit (D.C.), Biochemistry and Molecular Biology Department; Department of Biostatistics (C.M.), Lyon University Hospital; and Reference Centre for Inherited Metabolic Diseases (B.D.), Department of Child Neurology, Marseille University Hospital, France
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Mabondzo A, van de Kamp J, Mercimek-Andrews S. Dodecyl creatine ester therapy: from promise to reality. Cell Mol Life Sci 2024; 81:186. [PMID: 38632116 PMCID: PMC11024018 DOI: 10.1007/s00018-024-05218-y] [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: 01/18/2024] [Revised: 02/26/2024] [Accepted: 03/05/2024] [Indexed: 04/19/2024]
Abstract
Pathogenic variants in SLC6A8, the gene which encodes creatine transporter SLC6A8, prevent creatine uptake in the brain and result in a variable degree of intellectual disability, behavioral disorders (e.g., autism spectrum disorder), epilepsy, and severe speech and language delay. There are no treatments to improve neurodevelopmental outcomes for creatine transporter deficiency (CTD). In this spotlight, we summarize recent advances in innovative molecules to treat CTD, with a focus on dodecyl creatine ester, the most promising drug candidate.
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Affiliation(s)
- Aloïse Mabondzo
- Paris Saclay University, CEA, Medicines and Healthcare Technologies Department (MTS), SPI, Neurovascular Unit Research and Therapeutic Innovation Laboratory, 91191, Gif-sur-Yvette cedex, France.
| | - Jiddeke van de Kamp
- Department of Human Genetics, Amsterdam UMC, Vrije Universtiteit Amsterdam, Amsterdam, The Netherlands
| | - Saadet Mercimek-Andrews
- Department of Medical Genetics, Faculty of Medicine and Dentistry, Neurosciences and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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Balestrino M, Adriano E, Alì PA, Pardini M. Selective Alteration of the Left Arcuate Fasciculus in Two Patients Affected by Creatine Transporter Deficiency. Brain Sci 2024; 14:337. [PMID: 38671990 PMCID: PMC11048612 DOI: 10.3390/brainsci14040337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/11/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024] Open
Abstract
(1) Background: In hereditary creatine transporter deficiency (CTD), there is an absence of creatine in the brain and neurological symptoms are present, including severe language impairment. However, the pathological changes caused by creatine deficiency that generate neuropsychological symptoms have been poorly studied. (2) Aims: To investigate if the language impairment in CTD is underpinned by possible pathological changes. (3) Methods: We used MRI tractography to investigate the trophism of the left arcuate fasciculus, a white matter bundle connecting Wernicke's and Broca's language areas that is specifically relevant for language establishment and maintenance, in two patients (28 and 18 y.o.). (4) Results: The T1 and T2 MRI imaging results were unremarkable, but the left arcuate fasciculus showed a marked decrease in mean fractional anisotropy (FA) compared to healthy controls. In contrast, the FA values in the corticospinal tract were similar to those of healthy controls. Although white matter atrophy has been reported in CTD, this is the first report to show a selective abnormality of the language-relevant arcuate fasciculus, suggesting a possible region-specific impact of creatine deficiency.
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Affiliation(s)
- Maurizio Balestrino
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Sciences (DINOGMI), University of Genoa, 16132 Genoa, Italy; (E.A.); (P.A.A.); (M.P.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Enrico Adriano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Sciences (DINOGMI), University of Genoa, 16132 Genoa, Italy; (E.A.); (P.A.A.); (M.P.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Paolo Alessandro Alì
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Sciences (DINOGMI), University of Genoa, 16132 Genoa, Italy; (E.A.); (P.A.A.); (M.P.)
| | - Matteo Pardini
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Sciences (DINOGMI), University of Genoa, 16132 Genoa, Italy; (E.A.); (P.A.A.); (M.P.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
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6
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Bian X, Zhu J, Jia X, Liang W, Yu S, Li Z, Zhang W, Rao Y. Suggestion of creatine as a new neurotransmitter by approaches ranging from chemical analysis and biochemistry to electrophysiology. eLife 2023; 12:RP89317. [PMID: 38126335 PMCID: PMC10735228 DOI: 10.7554/elife.89317] [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] [Indexed: 12/23/2023] Open
Abstract
The discovery of a new neurotransmitter, especially one in the central nervous system, is both important and difficult. We have been searching for new neurotransmitters for 12 y. We detected creatine (Cr) in synaptic vesicles (SVs) at a level lower than glutamate and gamma-aminobutyric acid but higher than acetylcholine and 5-hydroxytryptamine. SV Cr was reduced in mice lacking either arginine:glycine amidinotransferase (a Cr synthetase) or SLC6A8, a Cr transporter with mutations among the most common causes of intellectual disability in men. Calcium-dependent release of Cr was detected after stimulation in brain slices. Cr release was reduced in Slc6a8 and Agat mutants. Cr inhibited neocortical pyramidal neurons. SLC6A8 was necessary for Cr uptake into synaptosomes. Cr was found by us to be taken up into SVs in an ATP-dependent manner. Our biochemical, chemical, genetic, and electrophysiological results are consistent with the possibility of Cr as a neurotransmitter, though not yet reaching the level of proof for the now classic transmitters. Our novel approach to discover neurotransmitters is to begin with analysis of contents in SVs before defining their function and physiology.
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Affiliation(s)
- Xiling Bian
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
| | - Jiemin Zhu
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
| | - Xiaobo Jia
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
| | - Wenjun Liang
- Chinese Institutes of Medical Research, Capital Medical UniversityBeijingChina
- Changping Laboratory, Yard 28, Science Park Road, Changping DistrictBeijingChina
| | - Sihan Yu
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Changping Laboratory, Yard 28, Science Park Road, Changping DistrictBeijingChina
| | - Zhiqiang Li
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
| | - Wenxia Zhang
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institutes of Medical Research, Capital Medical UniversityBeijingChina
- Institute of Molecular Physiology, Shenzhen Bay LaboratoryShenzhenChina
| | - Yi Rao
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
- Chinese Institutes of Medical Research, Capital Medical UniversityBeijingChina
- Changping Laboratory, Yard 28, Science Park Road, Changping DistrictBeijingChina
- Institute of Molecular Physiology, Shenzhen Bay LaboratoryShenzhenChina
- Research Unit of Medical Neurobiology, Chinese Academy of Medical SciencesBeijingChina
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7
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Kukułowicz J, Pietrzak-Lichwa K, Klimończyk K, Idlin N, Bajda M. The SLC6A15-SLC6A20 Neutral Amino Acid Transporter Subfamily: Functions, Diseases, and Their Therapeutic Relevance. Pharmacol Rev 2023; 76:142-193. [PMID: 37940347 DOI: 10.1124/pharmrev.123.000886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 09/07/2023] [Accepted: 11/02/2023] [Indexed: 11/10/2023] Open
Abstract
The neutral amino acid transporter subfamily that consists of six members, consecutively SLC6A15-SLC620, also called orphan transporters, represents membrane, sodium-dependent symporter proteins that belong to the family of solute carrier 6 (SLC6). Primarily, they mediate the transport of neutral amino acids from the extracellular milieu toward cell or storage vesicles utilizing an electric membrane potential as the driving force. Orphan transporters are widely distributed throughout the body, covering many systems; for instance, the central nervous, renal, or intestinal system, supplying cells into molecules used in biochemical, signaling, and building pathways afterward. They are responsible for intestinal absorption and renal reabsorption of amino acids. In the central nervous system, orphan transporters constitute a significant medium for the provision of neurotransmitter precursors. Diseases related with aforementioned transporters highlight their significance; SLC6A19 mutations are associated with metabolic Hartnup disorder, whereas altered expression of SLC6A15 has been associated with a depression/stress-related disorders. Mutations of SLC6A18-SLCA20 cause iminoglycinuria and/or hyperglycinuria. SLC6A18-SLC6A20 to reach the cellular membrane require an ancillary unit ACE2 that is a molecular target for the spike protein of the SARS-CoV-2 virus. SLC6A19 has been proposed as a molecular target for the treatment of metabolic disorders resembling gastric surgery bypass. Inhibition of SLC6A15 appears to have a promising outcome in the treatment of psychiatric disorders. SLC6A19 and SLC6A20 have been suggested as potential targets in the treatment of COVID-19. In this review, we gathered recent advances on orphan transporters, their structure, functions, related disorders, and diseases, and in particular their relevance as therapeutic targets. SIGNIFICANCE STATEMENT: The following review systematizes current knowledge about the SLC6A15-SLCA20 neutral amino acid transporter subfamily and their therapeutic relevance in the treatment of different diseases.
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Affiliation(s)
- Jędrzej Kukułowicz
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Krzysztof Pietrzak-Lichwa
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Klaudia Klimończyk
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Nathalie Idlin
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Marek Bajda
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
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8
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Horvat D, Kaminski M, Ma Y. A case of drug-resistant epilepsy and autism with de novo SLC6A8 gene variant. Seizure 2023; 113:16-18. [PMID: 37924775 DOI: 10.1016/j.seizure.2023.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 10/19/2023] [Accepted: 10/22/2023] [Indexed: 11/06/2023] Open
Affiliation(s)
- David Horvat
- Department of Neurology, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bethesda, MD, 20889 USA
| | - Matthew Kaminski
- University of Maryland, 1000 Hilltop Cir, Baltimore, MD, 21250 USA
| | - Yitao Ma
- Department of Neurology, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bethesda, MD, 20889 USA.
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9
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Rahhal S, Farmer C, Thurm A, Wassif CA, Cawley NX, Perreault J, Dang Do A, Bianconi S, Hannah-Shmouni F, Guthrie W, Cubit LS, Miller JS, Sutton VR, Koeberl D, Porter FD. Elevated amyloid beta peptides and total tau in cerebrospinal fluid in individuals with Creatine transporter deficiency. Mol Genet Metab Rep 2023; 37:101001. [PMID: 37662495 PMCID: PMC10470314 DOI: 10.1016/j.ymgmr.2023.101001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 09/05/2023] Open
Abstract
Background Creatine transporter deficiency (CTD) is a rare X-linked disorder of creatine transport caused by pathogenic variants in SLC6A8 (Xq28). The disorder is marked by developmental delay, especially speech delay. The biomarkers Aβ40, Aβ42 and total tau are abnormal in Alzheimer disease (AD), a common neurodegenerative disorder pathologically characterized by Aβ peptide containing amyloid plaques and tau neurofibrillary tangles. Although CTD results in neuronal energy deficiency, the pathological processes underlying the CTD phenotype are not fully characterized. Methods Cerebral spinal fluid (CSF) was collected as an optional part of a natural history study of CTD. Aβ40, Aβ42 and total tau levels were quantified in CSF from individuals with CTD and from age-appropriate comparison samples. Neuro3-Plex enzyme-linked immunoassay was performed on a Quanterix SR-X instrument. The Vineland Adaptive Behavior Scale, 3rd Edition was used to determine an overall Adaptive Behavior Composite (ABC) standard score. Results CSF from 12 individuals with CTD and 23 age appropriate non-CTD comparison samples were analyzed. We found that levels of total tau [t(32) = 4.05, p = 0.0003], Aβ40 [t(31) = 6.11, p < 0.0001], and Aβ42 [t(32) = 3.20, p = 0.003] were elevated in the participants with CTD relative to the comparison group. Additionally, except for one individual that we considered an outlier, all three biomarkers correlated inversely with the adaptive behavior score (total tau: ρ = -0.60 [-0.88, 0.005]; Aβ40: ρ = -0.67 [-0.91, -0.12]; Aβ42: ρ = -0.62 [-0.89, -0.02]). Conclusion We describe here the novel finding of elevated protein biomarkers in the CSF of individuals with CTD. Aβ40, Aβ42 and total tau are markedly elevated in individuals with CTD compared to comparison samples, and increased levels of these biomarkers inversely correlated with ABC scores. We hypothesize that elevated CSF levels of Aβ40 and Aβ42 are due to cellular energy deficiency. Elevated CSF total tau levels may indicate ongoing neuronal damage. The observed inverse correlation of Vineland ABC scores with increased biomarker levels needs to be confirmed in a larger CTD cohort; however, our observation of increased Aβ40, Aβ42 and total tau levels in CSF from individuals with CTD may provide insight into pathological mechanisms contributing to the CTD phenotype and may prove useful as supportive data in future therapeutic trials.
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Affiliation(s)
- Samar Rahhal
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Cristan Farmer
- Neurodevelopmental and Behavioral Phenotyping Service, National Institute of Mental Health, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Audrey Thurm
- Neurodevelopmental and Behavioral Phenotyping Service, National Institute of Mental Health, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Christopher A. Wassif
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Niamh X. Cawley
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - John Perreault
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - An Dang Do
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Simona Bianconi
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Fady Hannah-Shmouni
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Whitney Guthrie
- Center for Autism Research, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Developmental and Behavioral Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Laura S. Cubit
- Center for Autism Research, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Judith S. Miller
- Center for Autism Research, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Developmental and Behavioral Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - V. Reid Sutton
- Department of Molecular & Human Genetics, Baylor College of Medicine & Texas Children's Hospital, USA
| | - Dwight Koeberl
- Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA
| | - Forbes D. Porter
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, USA
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10
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Broca-Brisson L, Harati R, Disdier C, Mozner O, Gaston-Breton R, Maïza A, Costa N, Guyot AC, Sarkadi B, Apati A, Skelton MR, Madrange L, Yates F, Armengaud J, Hamoudi R, Mabondzo A. Deciphering neuronal deficit and protein profile changes in human brain organoids from patients with creatine transporter deficiency. eLife 2023; 12:RP88459. [PMID: 37830910 PMCID: PMC10575631 DOI: 10.7554/elife.88459] [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] [Indexed: 10/14/2023] Open
Abstract
Creatine transporter deficiency (CTD) is an X-linked disease caused by mutations in the SLC6A8 gene. The impaired creatine uptake in the brain results in intellectual disability, behavioral disorders, language delay, and seizures. In this work, we generated human brain organoids from induced pluripotent stem cells of healthy subjects and CTD patients. Brain organoids from CTD donors had reduced creatine uptake compared with those from healthy donors. The expression of neural progenitor cell markers SOX2 and PAX6 was reduced in CTD-derived organoids, while GSK3β, a key regulator of neurogenesis, was up-regulated. Shotgun proteomics combined with integrative bioinformatic and statistical analysis identified changes in the abundance of proteins associated with intellectual disability, epilepsy, and autism. Re-establishment of the expression of a functional SLC6A8 in CTD-derived organoids restored creatine uptake and normalized the expression of SOX2, GSK3β, and other key proteins associated with clinical features of CTD patients. Our brain organoid model opens new avenues for further characterizing the CTD pathophysiology and supports the concept that reinstating creatine levels in patients with CTD could result in therapeutic efficacy.
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Affiliation(s)
- Léa Broca-Brisson
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Rania Harati
- Department of Pharmacy Practice and Pharmacotherapeutics, College of Pharmacy, University of SharjahSharjahUnited Arab Emirates
- Sharjah Institute for Medical Research, University of SharjahSharjahUnited Arab Emirates
| | | | - Orsolya Mozner
- Institute of Enzymology, Research Centre for Natural Sciences, ELKH, and Doctoral School of Molecular Medicine, Semmelweis UniversityBudapestHungary
| | - Romane Gaston-Breton
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Auriane Maïza
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Narciso Costa
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Anne-Cécile Guyot
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Balazs Sarkadi
- Institute of Enzymology, Research Centre for Natural Sciences, ELKH, and Doctoral School of Molecular Medicine, Semmelweis UniversityBudapestHungary
| | - Agota Apati
- Institute of Enzymology, Research Centre for Natural Sciences, ELKH, and Doctoral School of Molecular Medicine, Semmelweis UniversityBudapestHungary
| | - Matthew R Skelton
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children’s Research FoundationCincinnatiUnited States
| | - Lucie Madrange
- SupBiotech/Service d'Etude des Prions et des Infections Atypiques (SEPIA), Institut François Jacob, CEA, Université Paris SaclayParisFrance
| | - Frank Yates
- SupBiotech/Service d'Etude des Prions et des Infections Atypiques (SEPIA), Institut François Jacob, CEA, Université Paris SaclayParisFrance
| | - Jean Armengaud
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPIBagnols-sur-CèzeFrance
| | - Rifat Hamoudi
- Clinical Sciences Department, College of Medicine, University of SharjahSharjahUnited Arab Emirates
- Division of Surgery and Interventional Science, University College LondonLondonUnited Kingdom
- ASPIRE Precision Medicine Research Institute Abu Dhabi, University of SharjahSharjahUnited Arab Emirates
| | - Aloïse Mabondzo
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
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11
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Li J, Xu S. Diagnosis and Treatment of X-Linked Creatine Transporter Deficiency: Case Report and Literature Review. Brain Sci 2023; 13:1382. [PMID: 37891751 PMCID: PMC10605349 DOI: 10.3390/brainsci13101382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/18/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
(1) Background: X-linked creatine transporter deficiency (CTD) (OMIM 300036) is a rare group of inherited metabolic disorders characterized by global developmental delay/intellectual disability (GDD/ID), seizures, autistic behavior, and movement disorders. Pathogenic variants in the SLC6A8 gene, located at Xq28, are causative of the disease, leading to impaired creatine transport into the brain. Supplementation with creatine and its precursors, glycine and arginine, has been attempted, yet the treatment efficacy remains controversial. (2) Methods: Here we report a de novo SLC6A8 variant in a boy aged 3 years 9 months presenting with GDD, autistic behavior, and epilepsy. Elevated urinary creatine/creatinine ratio and diminished creatine peak on brain MR spectroscopy suggested the diagnosis of CTD. Genetic sequencing revealed a de novo hemizygous frameshift variant (NM_005629: c.1136_1137del, p. Glu379ValfsTer85). Creatine supplementation therapy was initiated after definitive diagnosis. Electroencephalography and MR spectroscopy were monitored during follow-up in concurrence with neuropsychological evaluations. The clinical phenotype and treatment response of CTD were summarized by systematic view of the literature. (3) Results: In silico analysis showed this variant to be deleterious, probably interfering with substrate binding and conformational changes during creatine transport. Creatine supplementation therapy led to seizure cessation and modest cognitive improvement after half-year's treatment. (4) Conclusions: This case highlights the importance of MR spectroscopy and metabolic screening in males with GDD/ID, allowing for early diagnosis and therapeutic intervention. Mechanistic understanding and case-per-se analysis are required to enable precision treatment for the patients.
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Affiliation(s)
| | - Sanqing Xu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074, China;
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12
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Mabondzo A, Harati R, Broca-Brisson L, Guyot AC, Costa N, Cacciante F, Putignano E, Baroncelli L, Skelton MR, Saab C, Martini E, Benech H, Joudinaud T, Gaillard JC, Armengaud J, Hamoudi R. Dodecyl creatine ester improves cognitive function and identifies key protein drivers including KIF1A and PLCB1 in a mouse model of creatine transporter deficiency. Front Mol Neurosci 2023; 16:1118707. [PMID: 37063368 PMCID: PMC10103630 DOI: 10.3389/fnmol.2023.1118707] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/20/2023] [Indexed: 04/03/2023] Open
Abstract
Creatine transporter deficiency (CTD), a leading cause of intellectual disability is a result of the mutation in the gene encoding the creatine transporter SLC6A8, which prevents creatine uptake into the brain, causing mental retardation, expressive speech and language delay, autistic-like behavior and epilepsy. Preclinical in vitro and in vivo data indicate that dodecyl creatine ester (DCE) which increases the creatine brain content, might be a therapeutic option for CTD patients. To gain a better understanding of the pathophysiology and DCE treatment efficacy in CTD, this study focuses on the identification of biomarkers related to cognitive improvement in a Slc6a8 knockout mouse model (Slc6a8−/y) engineered to mimic the clinical features of CTD patients which have low brain creatine content. Shotgun proteomics analysis of 4,035 proteins in four different brain regions; the cerebellum, cortex, hippocampus (associated with cognitive functions) and brain stem, and muscle as a control, was performed in 24 mice. Comparison of the protein abundance in the four brain regions between DCE-treated intranasally Slc6a8−/y mice and wild type and DCE-treated Slc6a8−/y and vehicle group identified 14 biomarkers, shedding light on the mechanism of action of DCE. Integrative bioinformatics and statistical modeling identified key proteins in CTD, including KIF1A and PLCB1. The abundance of these proteins in the four brain regions was significantly correlated with both the object recognition and the Y-maze tests. Our findings suggest a major role for PLCB1, KIF1A, and associated molecules in the pathogenesis of CTD.
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Affiliation(s)
- Aloïse Mabondzo
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (MTS), Gif sur Yvette, France
- *Correspondence: Aloïse Mabondzo,
| | - Rania Harati
- Department of Pharmacy Practice and Pharmacotherapeutics, College of Pharmacy, University of Sharja, Sharjah, United Arab Emirates
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates
| | - Léa Broca-Brisson
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (MTS), Gif sur Yvette, France
| | - Anne-Cécile Guyot
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (MTS), Gif sur Yvette, France
| | - Narciso Costa
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (MTS), Gif sur Yvette, France
| | | | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Pisa, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), Pisa, Italy
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Matthew R. Skelton
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States
| | - Cathy Saab
- Université de Paris and Université Paris Saclay, CEA, Stabilité Génétique Cellules Souches et Radiations, Fontenay aux Roses, France
| | - Emmanuelle Martini
- Université de Paris and Université Paris Saclay, CEA, Stabilité Génétique Cellules Souches et Radiations, Fontenay aux Roses, France
| | | | | | - Jean-Charles Gaillard
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé (MTS), INRAE, Bagnol sur Cèze, France
| | - Jean Armengaud
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé (MTS), INRAE, Bagnol sur Cèze, France
| | - Rifat Hamoudi
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates
- Clinical Sciences Department, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Division of Surgery and Interventional Science, University College London, London, United Kingdom
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13
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Ghirardini E, Sagona G, Marquez-Galera A, Calugi F, Navarron CM, Cacciante F, Chen S, Di Vetta F, Dadà L, Mazziotti R, Lupori L, Putignano E, Baldi P, Lopez-Atalaya JP, Pizzorusso T, Baroncelli L. Cell-specific vulnerability to metabolic failure: the crucial role of parvalbumin expressing neurons in creatine transporter deficiency. Acta Neuropathol Commun 2023; 11:34. [PMID: 36882863 PMCID: PMC9990224 DOI: 10.1186/s40478-023-01533-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/14/2023] [Indexed: 03/09/2023] Open
Abstract
Mutations in the solute carrier family 6-member 8 (Slc6a8) gene, encoding the protein responsible for cellular creatine (Cr) uptake, cause Creatine Transporter Deficiency (CTD), an X-linked neurometabolic disorder presenting with intellectual disability, autistic-like features, and epilepsy. The pathological determinants of CTD are still poorly understood, hindering the development of therapies. In this study, we generated an extensive transcriptomic profile of CTD showing that Cr deficiency causes perturbations of gene expression in excitatory neurons, inhibitory cells, and oligodendrocytes which result in remodeling of circuit excitability and synaptic wiring. We also identified specific alterations of parvalbumin-expressing (PV+) interneurons, exhibiting a reduction in cellular and synaptic density, and a hypofunctional electrophysiological phenotype. Mice lacking Slc6a8 only in PV+ interneurons recapitulated numerous CTD features, including cognitive deterioration, impaired cortical processing and hyperexcitability of brain circuits, demonstrating that Cr deficit in PV+ interneurons is sufficient to determine the neurological phenotype of CTD. Moreover, a pharmacological treatment targeted to restore the efficiency of PV+ synapses significantly improved cortical activity in Slc6a8 knock-out animals. Altogether, these data demonstrate that Slc6a8 is critical for the normal function of PV+ interneurons and that impairment of these cells is central in the disease pathogenesis, suggesting a novel therapeutic venue for CTD.
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Affiliation(s)
- Elsa Ghirardini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone (PI), Italy. .,Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy.
| | - Giulia Sagona
- Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy
| | - Angel Marquez-Galera
- Instituto de Neurociencias, Universidad Miguel Hernández - Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramon Y Cajal, S/N, 03550, Sant Joan d'Alacant, Alicante, Spain
| | - Francesco Calugi
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Via Di San Salvi 12, 50135, Florence, Italy.,BIO@SNS Lab, Scuola Normale Superiore Di Pisa, Piazza Dei Cavalieri 7, 56126, Pisa, Italy
| | - Carmen M Navarron
- Instituto de Neurociencias, Universidad Miguel Hernández - Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramon Y Cajal, S/N, 03550, Sant Joan d'Alacant, Alicante, Spain
| | - Francesco Cacciante
- BIO@SNS Lab, Scuola Normale Superiore Di Pisa, Piazza Dei Cavalieri 7, 56126, Pisa, Italy
| | - Siwei Chen
- Department of Computer Science and Institute for Genomics and Bioinformatics, University of California, Irvine, CA, 92697-3435, USA
| | - Federica Di Vetta
- Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy
| | - Lorenzo Dadà
- Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy
| | - Raffaele Mazziotti
- Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Via Di San Salvi 12, 50135, Florence, Italy
| | - Leonardo Lupori
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone (PI), Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy
| | - Pierre Baldi
- Department of Computer Science and Institute for Genomics and Bioinformatics, University of California, Irvine, CA, 92697-3435, USA
| | - Jose P Lopez-Atalaya
- Instituto de Neurociencias, Universidad Miguel Hernández - Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramon Y Cajal, S/N, 03550, Sant Joan d'Alacant, Alicante, Spain
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy.,BIO@SNS Lab, Scuola Normale Superiore Di Pisa, Piazza Dei Cavalieri 7, 56126, Pisa, Italy
| | - Laura Baroncelli
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone (PI), Italy.,Institute of Neuroscience, National Research Council (CNR), Via Giuseppe Moruzzi 1, 56124, Pisa, Italy
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14
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Almatrafi M, Al-Sabban Z, Balkhy S, Abumansour IS. Case Report: X-Linked Creatine Transporter Deficiency in Two Saudi Brothers with Autism. J Autism Dev Disord 2023; 53:1273-1278. [PMID: 36520361 DOI: 10.1007/s10803-022-05860-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Mohammed Almatrafi
- Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 127, Makkah, 21961, Saudi Arabia
| | - Zehour Al-Sabban
- Department of Radiology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Soher Balkhy
- General Pediatric Section, Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Iman Sabri Abumansour
- Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 127, Makkah, 21961, Saudi Arabia.
- Pediatric Neurology Section, Department of Pediatrics, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah, 21499, Saudi Arabia.
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15
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Tise CG, Palma MJ, Cusmano-Ozog KP, Matalon DR. Creatine Transporter Deficiency Presenting as Failure to Thrive: A Case Report of a Novel SLC6A8 Variant Causing a Treatable but Likely Underdiagnosed Genetic Disorder. J Investig Med High Impact Case Rep 2023; 11:23247096231154438. [PMID: 36752093 PMCID: PMC9909053 DOI: 10.1177/23247096231154438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Cerebral creatine deficiency syndromes (CCDS) are a rare group of inherited metabolic disorders (IMDs) that often present with nonspecific findings including global developmental delay (GDD), intellectual disability (ID), seizures, hypotonia, and behavioral differences. Creatine transporter (CRTR) deficiency is the most common CCDS, exhibiting X-linked inheritance and an estimated prevalence as high as 2.6% in individuals with neurodevelopmental disorders. Here, we present a 20-month-old boy with worsening failure to thrive (FTT) and GDD admitted for evaluation. He was found to have persistently low serum creatinine levels and a family history notable for a mother with learning disabilities and a maternal male cousin with GDD. Urine analyses revealed a marked elevation of creatine and elevated creatine:creatinine ratio suggestive of CRTR deficiency. Molecular genetic testing of SLC6A8 identified a maternally inherited hemizygous variant and brain magnetic resonance spectroscopy (MRS) showed diffusely diminished creatine peaks, further supporting the diagnosis of CRTR deficiency. The proband was started on creatine, arginine, and glycine supplementation and has demonstrated improved development. This case highlights that CRTR deficiency should be considered in all patients presenting with FTT and abnormal neurodevelopmental features, particularly if creatinine levels are low on serum chemistry studies. The nonspecific presentation of this condition in males and females likely has resulted in CRTR deficiency being underdiagnosed. There are existing therapies for individuals affected with CRTR deficiency and other CCDS, highlighting the importance of early diagnosis and intervention for affected individuals.
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16
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Almaghrabi MA, Muthaffar OY, Alahmadi SA, Abdulsbhan MA, Bamusa M, Aljezani MA, Bahowarth SY, Alyazidi AS, Aggad WS. GAMT Deficiency Among Pediatric Population: Clinical and Molecular Characteristics and Management. Child Neurol Open 2023; 10:2329048X231215630. [PMID: 38020815 PMCID: PMC10655665 DOI: 10.1177/2329048x231215630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/12/2023] [Accepted: 11/03/2023] [Indexed: 12/01/2023] Open
Abstract
Objective: Analyze the treatment modalities used in real practice by synthesizing available literature. Methods: We reviewed and evaluated 52 cases of GAMT deficiency including 4 novel cases from Saudi Arabia diagnosed using whole-exome sequencing. All data utilized graphical presentation in the form of line charts and illustrated graphs. Results: The mean current age of was 117 months (±29.03) (range 12-372 months). The mean age of disease onset was 28.32 months (±13.68) (range 8 days - 252 months). The most prevalent symptom was developmental delays, mainly speech and motor, seizures, and intellectual disability. The male-to-female ratio was 3:1. Multiple treatments were used, with 54 pharmacological interventions, valproic acid being the most common. Creatinine monohydrate was the prevalent dietary intervention, with 25 patients reporting an improvement. Conclusion: The study suggests that efficient treatment with appropriate dietary intervention can improve patients' health, stressing that personalized treatment programs are essential in managing this disorder.
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Affiliation(s)
- Majdah A. Almaghrabi
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Osama Y. Muthaffar
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Sereen A. Alahmadi
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mashael A. Abdulsbhan
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mashael Bamusa
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Maram Ahmed Aljezani
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Anas S. Alyazidi
- Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Waheeb S. Aggad
- Department of Anatomy, Faculty of Medicine, University of Jeddah, Jeddah, Saudi Arabia
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17
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Farr CV, El-Kasaby A, Erdem FA, Sucic S, Freissmuth M, Sandtner W. Cooperative Binding of Substrate and Ions Drives Forward Cycling of the Human Creatine Transporter-1. Front Physiol 2022; 13:919439. [PMID: 35837012 PMCID: PMC9273935 DOI: 10.3389/fphys.2022.919439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/09/2022] [Indexed: 11/25/2022] Open
Abstract
Creatine serves as an ATP buffer and is thus an integral component of cellular energy metabolism. Most cells maintain their creatine levels via uptake by the creatine transporter (CRT-1, SLC6A8). The activity of CRT-1, therefore, is a major determinant of cytosolic creatine concentrations. We determined the kinetics of CRT-1 in real time by relying on electrophysiological recordings of transport-associated currents. Our analysis revealed that CRT-1 harvested the concentration gradient of NaCl and the membrane potential but not the potassium gradient to achieve a very high concentrative power. We investigated the mechanistic basis for the ability of CRT-1 to maintain the forward cycling mode in spite of high intracellular concentrations of creatine: this is achieved by cooperative binding of substrate and co-substrate ions, which, under physiological ion conditions, results in a very pronounced (i.e. about 500-fold) drop in the affinity of creatine to the inward-facing state of CRT-1. Kinetic estimates were integrated into a mathematical model of the transport cycle of CRT-1, which faithfully reproduced all experimental data. We interrogated the kinetic model to examine the most plausible mechanistic basis of cooperativity: based on this systematic exploration, we conclude that destabilization of binary rather than ternary complexes is necessary for CRT-1 to maintain the observed cytosolic creatine concentrations. Our model also provides a plausible explanation why neurons, heart and skeletal muscle cells must express a creatine releasing transporter to achieve rapid equilibration of the intracellular creatine pool.
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Affiliation(s)
| | | | | | | | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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18
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Perry LD, Hogg SL, Bowdin S, Ambegaonkar G, Parker AP. Fifteen-minute consultation: The efficient investigation of infantile and childhood epileptic encephalopathies in the era of modern genomics. Arch Dis Child Educ Pract Ed 2022; 107:80-87. [PMID: 33414255 DOI: 10.1136/archdischild-2020-320606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/05/2020] [Accepted: 12/09/2020] [Indexed: 11/03/2022]
Abstract
The investigation of children presenting with infantile and childhood epileptic encephalopathies (ICEE) is challenging due to diverse aetiologies, overlapping phenotypes and the relatively low diagnostic yield of MRI, electroencephalography (EEG) and biochemical investigations. Careful history and thorough examination remain essential as these may identify an acquired cause or indicate more targeted investigation for a genetic disorder. Whole exome sequencing (WES) with analysis of a panel of candidate epilepsy genes has increased the diagnostic yield. Whole genome sequencing (WGS), particularly as a trio with both parents' DNA, is likely to supersede WES. Modern genomic investigation impacts on the timing and necessity of other testing. We propose a structured approach for children presenting with ICEE where there is diagnostic uncertainty, emphasising the importance of WGS or, if unavailable, WES early in the investigative process. We note the importance of expert review of all investigations, including radiology, neurophysiology and biochemistry, to confirm the technique used was appropriate as well as the results. It is essential to counsel families on the risks associated with the procedures, the yield of the procedures, findings that are difficult to interpret and implication of 'negative' results. Where children remain without a diagnosis despite comprehensive investigation, we note the importance of ongoing multidisciplinary care.
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Affiliation(s)
- Luke Daniel Perry
- Developmental Neurosciences, University College London, Great Ormond Street Institute of Child Health, London, UK
| | - Sarah Louise Hogg
- Biochemical Genetics Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Sarah Bowdin
- Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Gautam Ambegaonkar
- Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Alasdair Pj Parker
- Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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19
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Fischer FP, Kasture AS, Hummel T, Sucic S. Molecular and Clinical Repercussions of GABA Transporter 1 Variants Gone Amiss: Links to Epilepsy and Developmental Spectrum Disorders. Front Mol Biosci 2022; 9:834498. [PMID: 35295842 PMCID: PMC7612498 DOI: 10.3389/fmolb.2022.834498] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/01/2022] [Indexed: 12/15/2022] Open
Abstract
The human γ-aminobutyric acid (GABA) transporter 1 (hGAT-1) is the first member of the solute carrier 6 (SLC6) protein superfamily. GAT-1 (SLC6A1) is one of the main GABA transporters in the central nervous system. Its principal physiological role is retrieving GABA from the synapse into neurons and astrocytes, thus swiftly terminating neurotransmission. GABA is a key inhibitory neurotransmitter and shifts in GABAergic signaling can lead to pathological conditions, from anxiety and epileptic seizures to schizophrenia. Point mutations in the SLC6A1 gene frequently give rise to epilepsy, intellectual disability or autism spectrum disorders in the afflicted individuals. The mechanistic routes underlying these are still fairly unclear. Some loss-of-function variants impair the folding and intracellular trafficking of the protein (thus retaining the transporter in the endoplasmic reticulum compartment), whereas others, despite managing to reach their bona fide site of action at the cell surface, nonetheless abolish GABA transport activity (plausibly owing to structural/conformational defects). Whatever the molecular culprit(s), the physiological aftermath transpires into the absence of functional transporters, which in turn perturbs GABAergic actions. Dozens of mutations in the kin SLC6 family members are known to exhort protein misfolding. Such events typically elicit severe ailments in people, e.g., infantile parkinsonism-dystonia or X-linked intellectual disability, in the case of dopamine and creatine transporters, respectively. Flaws in protein folding can be rectified by small molecules known as pharmacological and/or chemical chaperones. The search for such apt remedies calls for a systematic investigation and categorization of the numerous disease-linked variants, by biochemical and pharmacological means in vitro (in cell lines and primary neuronal cultures) and in vivo (in animal models). We here give special emphasis to the utilization of the fruit fly Drosophila melanogaster as a versatile model in GAT-1-related studies. Jointly, these approaches can portray indispensable insights into the molecular factors underlying epilepsy, and ultimately pave the way for contriving efficacious therapeutic options for patients harboring pathogenic mutations in hGAT-1.
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Affiliation(s)
- Florian P. Fischer
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
- Department of Epileptology and Neurology, University of Aachen, Aachen, Germany
| | - Ameya S. Kasture
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Thomas Hummel
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
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20
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Duran‐Trio L, Fernandes‐Pires G, Grosse J, Soro‐Arnaiz I, Roux‐Petronelli C, Binz P, De Bock K, Cudalbu C, Sandi C, Braissant O. Creatine transporter-deficient rat model shows motor dysfunction, cerebellar alterations, and muscle creatine deficiency without muscle atrophy. J Inherit Metab Dis 2022; 45:278-291. [PMID: 34936099 PMCID: PMC9302977 DOI: 10.1002/jimd.12470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 12/11/2022]
Abstract
Creatine (Cr) is a nitrogenous organic acid and plays roles such as fast phosphate energy buffer to replenish ATP, osmolyte, antioxidant, neuromodulator, and as a compound with anabolic and ergogenic properties in muscle. Cr is taken from the diet or endogenously synthetized by the enzymes arginine:glycine amidinotransferase and guanidinoacetate methyltransferase, and specifically taken up by the transporter SLC6A8. Loss-of-function mutations in the genes encoding for the enzymes or the transporter cause creatine deficiency syndromes (CDS). CDS are characterized by brain Cr deficiency, intellectual disability with severe speech delay, behavioral troubles, epilepsy, and motor dysfunction. Among CDS, the X-linked Cr transporter deficiency (CTD) is the most prevalent with no efficient treatment so far. Different animal models of CTD show reduced brain Cr levels, cognitive deficiencies, and together they cover other traits similar to those of patients. However, motor function was poorly explored in CTD models, and some controversies in the phenotype exist in comparison with CTD patients. Our recently described Slc6a8Y389C knock-in rat model of CTD showed mild impaired motor function, morphological alterations in cerebellum, reduced muscular mass, Cr deficiency, and increased guanidinoacetate content in muscle, although no consistent signs of muscle atrophy. Our results indicate that such motor dysfunction co-occurred with both nervous and muscle dysfunctions, suggesting that muscle strength and performance as well as neuronal connectivity might be affected by this Cr deficiency in muscle and brain.
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Affiliation(s)
- Lara Duran‐Trio
- Service of Clinical ChemistryUniversity of Lausanne and Lausanne University Hospital of LausanneLausanneSwitzerland
| | - Gabriella Fernandes‐Pires
- Service of Clinical ChemistryUniversity of Lausanne and Lausanne University Hospital of LausanneLausanneSwitzerland
| | - Jocelyn Grosse
- Brain Mind InstituteEcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Ines Soro‐Arnaiz
- Department of Health Sciences and TechnologySwiss Federal Institute of Technology (ETH)ZurichSwitzerland
| | - Clothilde Roux‐Petronelli
- Service of Clinical ChemistryUniversity of Lausanne and Lausanne University Hospital of LausanneLausanneSwitzerland
| | - Pierre‐Alain Binz
- Service of Clinical ChemistryUniversity of Lausanne and Lausanne University Hospital of LausanneLausanneSwitzerland
| | - Katrien De Bock
- Department of Health Sciences and TechnologySwiss Federal Institute of Technology (ETH)ZurichSwitzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Carmen Sandi
- Brain Mind InstituteEcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Olivier Braissant
- Service of Clinical ChemistryUniversity of Lausanne and Lausanne University Hospital of LausanneLausanneSwitzerland
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21
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Effects of Delivering Guanidinoacetic Acid or Its Prodrug to the Neural Tissue: Possible Relevance for Creatine Transporter Deficiency. Brain Sci 2022; 12:brainsci12010085. [PMID: 35053827 PMCID: PMC8773658 DOI: 10.3390/brainsci12010085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/30/2021] [Accepted: 01/06/2022] [Indexed: 12/03/2022] Open
Abstract
The creatine precursor guanidinoacetate (GAA) was used as a dietary supplement in humans with no adverse events. Nevertheless, it has been suggested that GAA is epileptogenic or toxic to the nervous system. However, increased GAA content in rodents affected by guanidinoacetate methyltransferase (GAMT) deficiency might be responsible for their spared muscle function. Given these conflicting data, and lacking experimental evidence, we investigated whether GAA affected synaptic transmission in brain hippocampal slices. Incubation with 11.5 μM GAA (the highest concentration in the cerebrospinal fluid of GAMT-deficient patients) did not change the postsynaptic compound action potential. Even 1 or 2 mM had no effect, while 4 mM caused a reversible decrease in the potential. Guanidinoacetate increased creatine and phosphocreatine, but not after blocking the creatine transporter (also used by GAA). In an attempt to allow the brain delivery of GAA when there was a creatine transporter deficiency, we synthesized diacetyl guanidinoacetic acid ethyl ester (diacetyl-GAAE), a lipophilic derivative. In brain slices, 0.1 mM did not cause electrophysiological changes and improved tissue viability after blockage of the creatine transporter. However, diacetyl-GAAE did not increase creatine nor phosphocreatine in brain slices after blockage of the creatine transporter. We conclude that: (1) upon acute administration, GAA is neither epileptogenic nor neurotoxic; (2) Diacetyl-GAAE improves tissue viability after blockage of the creatine transporter but not through an increase in creatine or phosphocreatine. Diacetyl-GAAE might give rise to a GAA–phosphoGAA system that vicariates the missing creatine–phosphocreatine system. Our in vitro data show that GAA supplementation may be safe in the short term, and that a lipophilic GAA prodrug may be useful in creatine transporter deficiency.
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22
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Fernandes-Pires G, Braissant O. Current and potential new treatment strategies for creatine deficiency syndromes. Mol Genet Metab 2022; 135:15-26. [PMID: 34972654 DOI: 10.1016/j.ymgme.2021.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 12/16/2022]
Abstract
Creatine deficiency syndromes (CDS) are inherited metabolic disorders caused by mutations in GATM, GAMT and SLC6A8 and mainly affect central nervous system (CNS). AGAT- and GAMT-deficient patients lack the functional brain endogenous creatine (Cr) synthesis pathway but express the Cr transporter SLC6A8 at blood-brain barrier (BBB), and can thus be treated by oral supplementation of high doses of Cr. For Cr transporter deficiency (SLC6A8 deficiency or CTD), current treatment strategies benefit one-third of patients. However, as their phenotype is not completely reversed, and for the other two-thirds of CTD patients, the development of novel more effective therapies is needed. This article aims to review the current knowledge on Cr metabolism and CDS clinical aspects, highlighting their current treatment possibilities and the most recent research perspectives on CDS potential therapeutics designed, in particular, to bring new options for the treatment of CTD.
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Affiliation(s)
- Gabriella Fernandes-Pires
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland.
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23
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Chen HR, Zhang-Brotzge X, Morozov YM, Li Y, Wang S, Zhang HH, Kuan IS, Fugate EM, Mao H, Sun YY, Rakic P, Lindquist DM, DeGrauw T, Kuan CY. Creatine transporter deficiency impairs stress adaptation and brain energetics homeostasis. JCI Insight 2021; 6:e140173. [PMID: 34324436 PMCID: PMC8492331 DOI: 10.1172/jci.insight.140173] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/28/2021] [Indexed: 11/22/2022] Open
Abstract
The creatine transporter (CrT) maintains brain creatine (Cr) levels, but the effects of its deficiency on energetics adaptation under stress remain unclear. There are also no effective treatments for CrT deficiency, the second most common cause of X-linked intellectual disabilities. Herein, we examined the consequences of CrT deficiency in brain energetics and stress-adaptation responses plus the effects of intranasal Cr supplementation. We found that CrT-deficient (CrT–/y) mice harbored dendritic spine and synaptic dysgenesis. Nurtured newborn CrT–/y mice maintained baseline brain ATP levels, with a trend toward signaling imbalance between the p-AMPK/autophagy and mTOR pathways. Starvation elevated the signaling imbalance and reduced brain ATP levels in P3 CrT–/y mice. Similarly, CrT–/y neurons and P10 CrT–/y mice showed an imbalance between autophagy and mTOR signaling pathways and greater susceptibility to cerebral hypoxia-ischemia and ischemic insults. Notably, intranasal administration of Cr after cerebral ischemia increased the brain Cr/N-acetylaspartate ratio, partially averted the signaling imbalance, and reduced infarct size more potently than intraperitoneal Cr injection. These findings suggest important functions for CrT and Cr in preserving the homeostasis of brain energetics in stress conditions. Moreover, intranasal Cr supplementation may be an effective treatment for congenital CrT deficiency and acute brain injury.
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Affiliation(s)
- Hong-Ru Chen
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Xiaohui Zhang-Brotzge
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, Georgia, USA
| | - Yury M Morozov
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yuancheng Li
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Siming Wang
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | | | - Irena S Kuan
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, Georgia, USA
| | - Elizabeth M Fugate
- Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Hui Mao
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Yu-Yo Sun
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Pasko Rakic
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Diana M Lindquist
- Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Ton DeGrauw
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, Georgia, USA
| | - Chia-Yi Kuan
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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24
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Ghirardini E, Calugi F, Sagona G, Di Vetta F, Palma M, Battini R, Cioni G, Pizzorusso T, Baroncelli L. The Role of Preclinical Models in Creatine Transporter Deficiency: Neurobiological Mechanisms, Biomarkers and Therapeutic Development. Genes (Basel) 2021; 12:genes12081123. [PMID: 34440297 PMCID: PMC8392480 DOI: 10.3390/genes12081123] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Creatine (Cr) Transporter Deficiency (CTD) is an X-linked metabolic disorder, mostly caused by missense mutations in the SLC6A8 gene and presenting with intellectual disability, autistic behavior, and epilepsy. There is no effective treatment for CTD and patients need lifelong assistance. Thus, the research of novel intervention strategies is a major scientific challenge. Animal models are an excellent tool to dissect the disease pathogenetic mechanisms and drive the preclinical development of therapeutics. This review illustrates the current knowledge about Cr metabolism and CTD clinical aspects, with a focus on mainstay diagnostic and therapeutic options. Then, we discuss the rodent models of CTD characterized in the last decade, comparing the phenotypes expressed within clinically relevant domains and the timeline of symptom development. This analysis highlights that animals with the ubiquitous deletion/mutation of SLC6A8 genes well recapitulate the early onset and the complex pathological phenotype of the human condition. Thus, they should represent the preferred model for preclinical efficacy studies. On the other hand, brain- and cell-specific conditional mutants are ideal for understanding the basis of CTD at a cellular and molecular level. Finally, we explain how CTD models might provide novel insight about the pathogenesis of other disorders, including cancer.
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MESH Headings
- Animals
- Biomarkers/metabolism
- Brain Diseases, Metabolic, Inborn/metabolism
- Brain Diseases, Metabolic, Inborn/pathology
- Brain Diseases, Metabolic, Inborn/therapy
- Central Nervous System/pathology
- Creatine/deficiency
- Creatine/metabolism
- Disease Models, Animal
- Humans
- Mental Retardation, X-Linked/metabolism
- Mental Retardation, X-Linked/pathology
- Mental Retardation, X-Linked/therapy
- Mice
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/metabolism
- Rats
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Affiliation(s)
- Elsa Ghirardini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
| | - Francesco Calugi
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Giulia Sagona
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Federica Di Vetta
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Biology, University of Pisa, I-56126 Pisa, Italy
| | - Martina Palma
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126 Pisa, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126 Pisa, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Laura Baroncelli
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Correspondence:
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25
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Wawro AM, Gajera CR, Baker SA, Nirschl JJ, Vogel H, Montine TJ. Creatine transport and pathological changes in creatine transporter deficient mice. J Inherit Metab Dis 2021; 44:939-948. [PMID: 33389772 DOI: 10.1002/jimd.12358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 01/26/2023]
Abstract
The severe impact on brain function and lack of effective therapy for patients with creatine (Cr) transporter deficiency motivated the generation of three ubiquitous Slc6a8 deficient mice (-/y). While each mouse knock-out line has similar behavioral effects at 2 to 3 months of age, other features critical to the efficient use of these mice in drug discovery are unclear or lacking: the concentration of Cr in brain and heart differ widely between mouse lines, there are limited data on histopathologic changes, and no data on Cr uptake. Here, we determined survival, measured endogenous Cr and uptake of its deuterium-labeled analogue Cr-d3 using a liquid chromatography coupled with tandem mass spectrometry assay, and performed comprehensive histopathologic examination on the Slc6a8-/y mouse developed by Skelton et al. Our results show that Slc6a8-/y mice have widely varying organ-specific uptake of Cr-d3, significantly diminished growth with the exception of brain, progressive vacuolar myopathy, and markedly shortened lifespan.
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Affiliation(s)
- Adam M Wawro
- Department of Pathology, Stanford University, Stanford, California, USA
| | | | - Steven A Baker
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Jeffrey J Nirschl
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Thomas J Montine
- Department of Pathology, Stanford University, Stanford, California, USA
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26
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Do MHT, Cavagnaro J, Butt M, Terse PS, McKew JC. Use of an animal model of disease for toxicology enables identification of a juvenile no observed adverse effect level for cyclocreatine in creatine transporter deficiency. Regul Toxicol Pharmacol 2021; 123:104939. [PMID: 33961952 DOI: 10.1016/j.yrtph.2021.104939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/21/2021] [Accepted: 04/24/2021] [Indexed: 10/21/2022]
Abstract
In standard general toxicology studies in two species to support clinical development, cyclocreatine, a creatine analog for the treatment of creatine transporter deficiency, caused deaths, convulsions, and/or multi-organ pathology. The potential translatability of these findings to patients was evaluated by comparing toxicity of cyclocreatine in wild-type mice to creatine transporter-deficient mice, a model of the human disease. A biodistribution study indicated greater accumulation of cyclocreatine in the brains of wild-type mice, consistent with its ability to be transported by the creatine transporter. Subsequent toxicology studies confirmed greater sensitivity of wild-type mice to cyclocreatine-induced toxicity. Exposure at the no observed adverse effect level in creatine transporter-deficient (554 μg*hr/ml) mice exceeded exposure at the maximum tolerated dose in wild-type (248 μg*hr/ml) mice. When dosed at 300 mg/kg/day for 3 months, cyclocreatine-related mortality, convulsions, and multi-organ pathology were observed in wild-type mice whereas there were no adverse findings in creatine transporter-deficient mice. Brain vacuolation was common to both strains. Although transporter-deficient mice appeared to be more sensitive, the finding had no functional correlates in this strain. The results highlight the importance of considering models of disease for toxicology in cases where they may be relevant to assessing safety in the intended patient population.
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Affiliation(s)
- Minh-Ha Thi Do
- Lumos Pharma, 4200 Marathon Blvd Suite 200, Austin, TX, 78756, USA
| | | | - Mark Butt
- Tox Path Specialists, 8420 Gas House Pike Suite G, Frederick, MD, 21701, USA
| | - Pramod S Terse
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - John C McKew
- Lumos Pharma, 4200 Marathon Blvd Suite 200, Austin, TX, 78756, USA.
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27
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Kreider RB, Stout JR. Creatine in Health and Disease. Nutrients 2021; 13:nu13020447. [PMID: 33572884 PMCID: PMC7910963 DOI: 10.3390/nu13020447] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 12/14/2022] Open
Abstract
Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.
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Affiliation(s)
- Richard B. Kreider
- Human Clinical Research Facility, Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843, USA
- Correspondence:
| | - Jeffery R. Stout
- Physiology of Work and Exercise Response (POWER) Laboratory, Institute of Exercise Physiology and Rehabilitation Science, School of Kinesiology and Physical Therapy, University of Central Florida, 12494 University Blvd., Orlando, FL 32816, USA;
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28
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Duran-Trio L, Fernandes-Pires G, Simicic D, Grosse J, Roux-Petronelli C, Bruce SJ, Binz PA, Sandi C, Cudalbu C, Braissant O. A new rat model of creatine transporter deficiency reveals behavioral disorder and altered brain metabolism. Sci Rep 2021; 11:1636. [PMID: 33452333 PMCID: PMC7810893 DOI: 10.1038/s41598-020-80824-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/28/2020] [Indexed: 11/10/2022] Open
Abstract
Creatine is an organic compound used as fast phosphate energy buffer to recycle ATP, important in tissues with high energy demand such as muscle or brain. Creatine is taken from the diet or endogenously synthetized by the enzymes AGAT and GAMT, and specifically taken up by the transporter SLC6A8. Deficit in the endogenous synthesis or in the transport leads to Cerebral Creatine Deficiency Syndromes (CCDS). CCDS are characterized by brain creatine deficiency, intellectual disability with severe speech delay, behavioral troubles such as attention deficits and/or autistic features, and epilepsy. Among CCDS, the X-linked creatine transporter deficiency (CTD) is the most prevalent with no efficient treatment so far. Different mouse models of CTD were generated by doing long deletions in the Slc6a8 gene showing reduced brain creatine and cognitive deficiencies or impaired motor function. We present a new knock-in (KI) rat model of CTD holding an identical point mutation found in patients with reported lack of transporter activity. KI males showed brain creatine deficiency, increased urinary creatine/creatinine ratio, cognitive deficits and autistic-like traits. The Slc6a8Y389C KI rat fairly enriches the spectrum of CTD models and provides new data about the pathology, being the first animal model of CTD carrying a point mutation.
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Affiliation(s)
- Lara Duran-Trio
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Gabriella Fernandes-Pires
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Dunja Simicic
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Jocelyn Grosse
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Clothilde Roux-Petronelli
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Stephen J Bruce
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Pierre-Alain Binz
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Carmen Sandi
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland.
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29
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Beck M. Clinical Manifestation in Females with X-linked Metabolic Disorders: Genetic and Pathophysiological Considerations. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2021. [DOI: 10.1590/2326-4594-jiems-2020-0024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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30
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Yuan L, Wu XJ, Li WC, Zhuo C, Xu Z, Tan C, Ma R, Wang J, Pu J. SLC6A8 Knockdown Suppresses the Invasion and Migration of Human Hepatocellular Carcinoma Huh-7 and Hep3B Cells. Technol Cancer Res Treat 2020; 19:1533033820983029. [PMID: 33356959 PMCID: PMC7780307 DOI: 10.1177/1533033820983029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Liver cancer is considered the sixth most commonly diagnosed cancer and the fourth leading cause of cancer-related deaths worldwide. Currently, there is no specific and effective therapy for hepatocellular carcinoma. Therefore, developing novel diagnostic and therapeutic strategies against hepatocellular carcinoma is of paramount importance. Solute carrier family 6 member 8 (SLC6A8) encodes the solute carrier family 6-8 to transport creatine into cells in a Na+ and Cl-- dependent manner. SLC6A8 deficiency is characterized by intellectual disabilities, loss of speech, and behavioral abnormalities. Of concern, the association of SLC6A8 with hepatocellular carcinoma remains elusive. In this study, we revealed that SLC6A8 knockdown significantly induced apoptosis and suppressed the migration and invasion of Hep3B and Huh-7 cells. These findings depicted the vital role of SLC6A8 in the initiation and progression of human hepatocellular carcinoma.
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Affiliation(s)
- Lu Yuan
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Xian Jian Wu
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Wen Chuan Li
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Chenyi Zhuo
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - ZuoMing Xu
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Chuan Tan
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - RiHai Ma
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - JianChu Wang
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Jian Pu
- Hepatobiliary Surgery, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
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31
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Bhat S, El-Kasaby A, Freissmuth M, Sucic S. Functional and Biochemical Consequences of Disease Variants in Neurotransmitter Transporters: A Special Emphasis on Folding and Trafficking Deficits. Pharmacol Ther 2020; 222:107785. [PMID: 33310157 PMCID: PMC7612411 DOI: 10.1016/j.pharmthera.2020.107785] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/02/2020] [Indexed: 01/30/2023]
Abstract
Neurotransmitters, such as γ-aminobutyric acid, glutamate, acetyl choline, glycine and the monoamines, facilitate the crosstalk within the central nervous system. The designated neurotransmitter transporters (NTTs) both release and take up neurotransmitters to and from the synaptic cleft. NTT dysfunction can lead to severe pathophysiological consequences, e.g. epilepsy, intellectual disability, or Parkinson’s disease. Genetic point mutations in NTTs have recently been associated with the onset of various neurological disorders. Some of these mutations trigger folding defects in the NTT proteins. Correct folding is a prerequisite for the export of NTTs from the endoplasmic reticulum (ER) and the subsequent trafficking to their pertinent site of action, typically at the plasma membrane. Recent studies have uncovered some of the key features in the molecular machinery responsible for transporter protein folding, e.g., the role of heat shock proteins in fine-tuning the ER quality control mechanisms in cells. The therapeutic significance of understanding these events is apparent from the rising number of reports, which directly link different pathological conditions to NTT misfolding. For instance, folding-deficient variants of the human transporters for dopamine or GABA lead to infantile parkinsonism/dystonia and epilepsy, respectively. From a therapeutic point of view, some folding-deficient NTTs are amenable to functional rescue by small molecules, known as chemical and pharmacological chaperones.
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Affiliation(s)
- Shreyas Bhat
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Ali El-Kasaby
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria.
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32
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Cacciante F, Gennaro M, Sagona G, Mazziotti R, Lupori L, Cerri E, Putignano E, Butt M, Do MHT, McKew JC, Alessandrì MG, Battini R, Cioni G, Pizzorusso T, Baroncelli L. Cyclocreatine treatment ameliorates the cognitive, autistic and epileptic phenotype in a mouse model of Creatine Transporter Deficiency. Sci Rep 2020; 10:18361. [PMID: 33110151 PMCID: PMC7591530 DOI: 10.1038/s41598-020-75436-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/25/2020] [Indexed: 02/02/2023] Open
Abstract
Creatine Transporter Deficiency (CTD) is an inborn error of metabolism presenting with intellectual disability, behavioral disturbances and epilepsy. There is currently no cure for this disorder. Here, we employed novel biomarkers for monitoring brain function, together with well-established behavioral readouts for CTD mice, to longitudinally study the therapeutic efficacy of cyclocreatine (cCr) at the preclinical level. Our results show that cCr treatment is able to partially correct hemodynamic responses and EEG abnormalities, improve cognitive deficits, revert autistic-like behaviors and protect against seizures. This study provides encouraging data to support the potential therapeutic benefit of cyclocreatine or other chemically modified lipophilic analogs of Cr.
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Affiliation(s)
- Francesco Cacciante
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy.,BIO@SNS Lab, Scuola Normale Superiore di Pisa, 56125, Pisa, Italy
| | - Mariangela Gennaro
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy
| | - Giulia Sagona
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, 50135, Florence, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, 56128, Pisa, Italy
| | - Raffaele Mazziotti
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy
| | - Leonardo Lupori
- BIO@SNS Lab, Scuola Normale Superiore di Pisa, 56125, Pisa, Italy
| | - Elisa Cerri
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy
| | - Mark Butt
- Tox Path Specialists, Frederick, MD, 21701, USA
| | | | | | | | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, 56128, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, 56126, Pisa, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, 56128, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, 56126, Pisa, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, 50135, Florence, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy. .,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, 56128, Pisa, Italy.
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Farr CV, El-Kasaby A, Freissmuth M, Sucic S. The Creatine Transporter Unfolded: A Knotty Premise in the Cerebral Creatine Deficiency Syndrome. Front Synaptic Neurosci 2020; 12:588954. [PMID: 33192443 PMCID: PMC7644880 DOI: 10.3389/fnsyn.2020.588954] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022] Open
Abstract
Creatine provides cells with high-energy phosphates for the rapid reconstitution of hydrolyzed adenosine triphosphate. The eponymous creatine transporter (CRT1/SLC6A8) belongs to a family of solute carrier 6 (SLC6) proteins. The key role of CRT1 is to translocate creatine across tissue barriers and into target cells, such as neurons and myocytes. Individuals harboring mutations in the coding sequence of the human CRT1 gene develop creatine transporter deficiency (CTD), one of the pivotal underlying causes of cerebral creatine deficiency syndrome. CTD encompasses an array of clinical manifestations, including severe intellectual disability, epilepsy, autism, development delay, and motor dysfunction. CTD is characterized by the absence of cerebral creatine, which implies an indispensable role for CRT1 in supplying the brain cells with creatine. CTD-associated variants dramatically reduce or abolish creatine transport activity by CRT1. Many of these are point mutations that are known to trigger folding defects, leading to the retention of encoded CRT1 proteins in the endoplasmic reticulum and precluding their delivery to the cell surface. Misfolding of several related SLC6 transporters also gives rise to detrimental pathologic conditions in people; e.g., mutations in the dopamine transporter induce infantile parkinsonism/dystonia, while mutations in the GABA transporter 1 cause treatment-resistant epilepsy. In some cases, folding defects are amenable to rescue by small molecules, known as pharmacological and chemical chaperones, which restore the cell surface expression and transport activity of the previously non-functional proteins. Insights from the recent molecular, animal and human case studies of CTD add toward our understanding of this complex disorder and reveal the wide-ranging effects elicited upon CRT1 dysfunction. This grants novel therapeutic prospects for the treatment of patients afflicted with CTD, e.g., modifying the creatine molecule to facilitate CRT1-independent entry into brain cells, or correcting folding-deficient and loss-of-function CTD variants using pharmacochaperones and/or allosteric modulators. The latter justifies a search for additional compounds with a capacity to correct mutation-specific defects.
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Affiliation(s)
| | | | | | - Sonja Sucic
- Institute of Pharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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Mazziotti R, Cacciante F, Sagona G, Lupori L, Gennaro M, Putignano E, Alessandrì MG, Ferrari A, Battini R, Cioni G, Pizzorusso T, Baroncelli L. Novel translational phenotypes and biomarkers for creatine transporter deficiency. Brain Commun 2020; 2:fcaa089. [PMID: 32954336 PMCID: PMC7472907 DOI: 10.1093/braincomms/fcaa089] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/20/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022] Open
Abstract
Creatine transporter deficiency is a metabolic disorder characterized by intellectual disability, autistic-like behaviour and epilepsy. There is currently no cure for creatine transporter deficiency, and reliable biomarkers of translational value for monitoring disease progression and response to therapeutics are sorely lacking. Here, we found that mice lacking functional creatine transporter display a significant alteration of neural oscillations in the EEG and a severe epileptic phenotype that are recapitulated in patients with creatine transporter deficiency. In-depth examination of knockout mice for creatine transporter also revealed that a decrease in EEG theta power is predictive of the manifestation of spontaneous seizures, a frequency that is similarly affected in patients compared to healthy controls. In addition, knockout mice have a highly specific increase in haemodynamic responses in the cerebral cortex following sensory stimuli. Principal component and Random Forest analyses highlighted that these functional variables exhibit a high performance in discriminating between pathological and healthy phenotype. Overall, our findings identify novel, translational and non-invasive biomarkers for the analysis of brain function in creatine transporter deficiency, providing a very reliable protocol to longitudinally monitor the efficacy of potential therapeutic strategies in preclinical, and possibly clinical, studies.
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Affiliation(s)
- Raffaele Mazziotti
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | | | - Giulia Sagona
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Leonardo Lupori
- BIO@SNS Lab, Scuola Normale Superiore di Pisa, Pisa I-56125, Italy
| | - Mariangela Gennaro
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Annarita Ferrari
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa I-56126, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa I-56126, Italy
| | - Tommaso Pizzorusso
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
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Sun WH, Zhuang DY, Wang Y, Xiao FF, Wu MY, Dong XR, Zhang P, Wang HJ, Zhou WH, Wu BB. [Clinical features and SLC6A8 gene mutations of cerebral creatine deficiency syndrome I: an analysis of two families]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2020; 22:482-487. [PMID: 32434645 PMCID: PMC7389393 DOI: 10.7499/j.issn.1008-8830.2002012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
This article reports the clinical and genetic features of two cases of cerebral creatine deficiency syndrome I (CCDSI) caused by SLC6A8 gene mutations. Both children were boys. Boy 1 (aged 2 years and 10 months) and Boy 2 (aged 8 years and 11 months) had the clinical manifestations of delayed mental and motor development, and convulsion. Their older brothers had the same symptoms. The mother of the boy 1 had mild intellectual disability. The genetic analysis showed two novel homozygous mutations, c.200G>A(p.Gly67Asp) and c.626_627delCT(p.Pro209Argfs*87), in the SLC6A8 gene on the X chromosome, both of which came from their mothers. These two novel mutations were rated as possible pathogenic mutations and were not reported in the literature before. This study expands the mutation spectrum of the SLC6A8 gene and has great significance in the diagnosis of boys with delayed development, and epilepsy.
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Affiliation(s)
- Wei-Hua Sun
- Pediatric Research Institute, Children's Hospital, Fudan University, Shanghai 201102, China.
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Uemura T, Ito S, Masuda T, Shimbo H, Goto T, Osaka H, Wada T, Couraud PO, Ohtsuki S. Cyclocreatine Transport by SLC6A8, the Creatine Transporter, in HEK293 Cells, a Human Blood-Brain Barrier Model Cell, and CCDSs Patient-Derived Fibroblasts. Pharm Res 2020; 37:61. [PMID: 32124083 DOI: 10.1007/s11095-020-2779-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/04/2020] [Indexed: 01/04/2023]
Abstract
PURPOSE Cyclocreatine, a creatine analog, is a candidate drug for treating patients with cerebral creatine deficiency syndromes (CCDSs) caused by creatine transporter (CRT, SLC6A8) deficiency, which reduces brain creatine level. The purpose of this study was to clarify the characteristics of cyclocreatine transport in HEK293 cells, which highly express endogenous CRT, in hCMEC/D3 cells, a human blood-brain barrier (BBB) model, and in CCDSs patient-derived fibroblasts with CRT mutations. METHODS Cells were incubated at 37°C with [14C]cyclocreatine (9 μM) and [14C]creatine (9 μM) for specified periods of times in the presence or absence of inhibitors, while the siRNAs were transfected by lipofection. Protein expression and mRNA expression were quantified using targeted proteomics and quantitative PCR, respectively. RESULTS [14C]Cyclocreatine was taken up by HEK293 cells in a time-dependent manner, while exhibiting saturable kinetics. The inhibition and siRNA knockdown studies demonstrated that the uptake of [14C]cyclocreatine by both HEK293 and hCMEC/D3 cells was mediated predominantly by CRT as well as [14C]creatine. In addition, uptake of [14C]cyclocreatine and [14C]creatine by the CCDSs patient-derived fibroblasts was found to be largely reduced. CONCLUSION The present study suggests that cyclocreatine is a CRT substrate, where CRT is the predominant contributor to influx of cyclocreatine into the brain at the BBB. Our findings provide vital insights for the purposes of treating CCDSs patients using cyclocreatine.
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Affiliation(s)
- Tatsuki Uemura
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Shingo Ito
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.,Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Takeshi Masuda
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.,Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Hiroko Shimbo
- Division of Neurology, Kanagawa Children's Medical Center, Kanagawa, 232-8555, Japan
| | - Tomohide Goto
- Division of Neurology, Kanagawa Children's Medical Center, Kanagawa, 232-8555, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical School, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Takahito Wada
- Department of Medical Ethics and Medical Genetics, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Pierre-Olivier Couraud
- Institut Cochin, Paris Descartes University, Inserm U1016, CNRS UMR8104, 75014, Paris, France
| | - Sumio Ohtsuki
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan. .,Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
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Functional characterization of monocarboxylate transporter 12 (SLC16A12/MCT12) as a facilitative creatine transporter. Drug Metab Pharmacokinet 2020; 35:281-287. [PMID: 32249133 DOI: 10.1016/j.dmpk.2020.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 01/27/2020] [Accepted: 01/27/2020] [Indexed: 12/20/2022]
Abstract
SLC16A12/MCT12 has been recently identified as a creatine transporter in a Xenopus oocyte expression system; however, the mechanism, by which MCT12 transports creatine, remains unclear. This study was performed to determine the functional and molecular characteristics of MCT12 in mammalian cells. The results showed that the uptake of [14C]creatine was not significantly increased in HEK293 cells transiently expressing MCT12 with or without CD147, a molecular chaperone, compared with mock cells. When [14C]creatine was accumulated in the cells with the aid of SLC6A8/CRT1, a concentrative creatine transporter, followed by assessing the remaining intracellular [14C]creatine after initiating efflux, coexpression of MCT12 resulted in a decrease in the intracellular [14C]creatine and remarkably enhanced the efflux of [14C]creatine from the cells in a time-dependent manner. This activity was not affected by extracellular pH. The creatine efflux activity involved dissipation by the mutations of conserved charged amino acids such as Arg37, Asp65 and Asp299 in the transmembrane domains, indicating direct involvement of MCT12 in the creatine efflux. These results suggest that MCT12 mediates facilitative diffusion of creatine, depending on the concentration gradient across the plasma membrane in mammalian cells. The finding may provide important clues to understanding the disposition kinetics of creatine and its derivatives.
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38
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Gorshkov K, Wang AQ, Sun W, Fisher E, Frigeni M, Singleton M, Thorne N, Class B, Huang W, Longo N, Do MT, Ottinger EA, Xu X, Zheng W. Phosphocyclocreatine is the dominant form of cyclocreatine in control and creatine transporter deficiency patient fibroblasts. Pharmacol Res Perspect 2019; 7:e00525. [PMID: 31859463 PMCID: PMC6924099 DOI: 10.1002/prp2.525] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/20/2019] [Accepted: 08/29/2019] [Indexed: 12/26/2022] Open
Abstract
Creatine transporter deficiency (CTD) is a metabolic disorder resulting in cognitive, motor, and behavioral deficits. Cyclocreatine (cCr), a creatine analog, has been explored as a therapeutic strategy for the treatment of CTD. We developed a rapid, selective, and accurate HILIC ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to simultaneously quantify the intracellular concentrations of cCr, creatine (Cr), creatine-d3 (Cr-d3), phosphocyclocreatine (pcCr), and phosphocreatine (pCr). Using HILIC-UPLC-MS/MS, we measured cCr and Cr-d3 uptake and their conversion to the phosphorylated forms in primary human control and CTD fibroblasts. Altogether, the data demonstrate that cCr enters cells and its dominant intracellular form is pcCr in both control and CTD patient cells. Therefore, cCr may replace creatine as a therapeutic strategy for the treatment of CTD.
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Affiliation(s)
- Kirill Gorshkov
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Amy Q. Wang
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Wei Sun
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Ethan Fisher
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Marta Frigeni
- Division of Medical GeneticsDepartment of PediatricsUniversity of UtahSalt Lake CityUTUSA
| | - Marc Singleton
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Natasha Thorne
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Bradley Class
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Wenwei Huang
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Nicola Longo
- Division of Medical GeneticsDepartment of PediatricsUniversity of UtahSalt Lake CityUTUSA
- Associated Regional and University Pathologists (ARUP) LaboratoriesSalt Lake CityUTUSA
| | | | - Elizabeth A. Ottinger
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Xin Xu
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
| | - Wei Zheng
- National Center for Advancing Translational SciencesNational Institutes of HealthBethesdaMDUSA
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Abdulla ZI, Pennington JL, Gutierrez A, Skelton MR. Creatine transporter knockout mice (Slc6a8) show increases in serotonin-related proteins and are resilient to learned helplessness. Behav Brain Res 2019; 377:112254. [PMID: 31542396 DOI: 10.1016/j.bbr.2019.112254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 12/11/2022]
Abstract
Approximately 20% of adults in the U.S. will experience an affective disorder during their life. While it is well established that serotonin (5-HT) is a crucial factor in mood, impaired cellular bioenergetics are also implicated. Creatine (Cr), through the Cr/Phospho-Cr (PCr) shuttle, maintains high ATP concentrations in the neuron. This system may be implicated in the etiology of affective disorders, as reduced Cr, PCr, and ATP are often seen in the brains of affected patients. To address this issue, Cr transporter (Crt) deficient male mice (Slc6a8-/y) and female mice heterozygous for Crt expression (Slc6a8+/-) were used to evaluate how a Cr deficient system would alter affective-like behaviors. Slc6a8-/y and Slc6a8+/- mice had faster escape latencies in learned helplessness, indicating a potential resilience to behavioral despair. Slc6a8-/y had decrease latency to immobility in the tail-suspension test and Slc6a8+/- had increased open entries in elevated zero maze, but all other variables matched those of wildtype mice, however. Slc6a8-/y mice have increased 5-hydroxyindoleacetic acid content in the hippocampus and striatum and increased monoamine oxidase protein and tryptophan hydroxylase-2 protein content in the hippocampus, while 5-HT levels are unchanged. This indicates an alteration to the 5-HTergic system in Cr deficient mice. Our results indicate that Cr plays a complex role in affective disorders and 5-HT, warranting further investigation.
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Affiliation(s)
- Zuhair I Abdulla
- Department of Pediatrics, University of Cincinnati College of Medicine, USA; Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
| | - Jordan L Pennington
- Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
| | - Arnold Gutierrez
- Department of Pediatrics, University of Cincinnati College of Medicine, USA; Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
| | - Matthew R Skelton
- Department of Pediatrics, University of Cincinnati College of Medicine, USA; Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, USA.
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Deletion of the Creatine Transporter (Slc6a8) in Dopaminergic Neurons Leads to Hyperactivity in Mice. J Mol Neurosci 2019; 70:102-111. [PMID: 31520365 DOI: 10.1007/s12031-019-01405-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 08/30/2019] [Indexed: 12/27/2022]
Abstract
The lack of cerebral creatine (Cr) causes intellectual disability and epilepsy. In addition, a significant portion of individuals with Cr transporter (Crt) deficiency (CTD), the leading cause of cerebral Cr deficiency syndromes (CCDS), are diagnosed with attention-deficit hyperactivity disorder. While the neurological effects of CTD are clear, the mechanisms that underlie these deficits are unknown. Part of this is due to the heterogenous nature of the brain and the unique metabolic demands of specific neuronal systems. Of particular interest related to Cr physiology are dopaminergic neurons, as many CCDS patients have ADHD and Cr has been implicated in dopamine-associated neurodegenerative disorders, such as Parkinson's and Huntington's diseases. The purpose of this study was to examine the effect of a loss of the Slc6a8 (Crt) gene in dopamine transporter (Slc6a3; DAT) expressing cells on locomotor activity and motor function as the mice age. Floxed Slc6a8 (Slc6a8flox) mice were mated to DATIREScre expressing mice to generate DAT-specific Slc6a8 knockouts (dCrt-/y). Locomotor activity, spontaneous activity, and performance in the challenging beam test were evaluated monthly in dCrt-/y and control (Slc6a8flox) mice from 3 to 12 months of age. dCrt-/y mice were hyperactive compared with controls throughout testing. In addition, dCrt-/y mice showed increased rearing and hindlimb steps in the spontaneous activity test. Latency to cross the narrow bridge was increased in dCrt-/y mice while foot slips were unchanged. Taken together, these data suggest that the lack of Cr in dopaminergic neurons causes hyperactivity while sparing motor function.
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41
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Tao D, Leister W, Huang W, Alimardanov A, LeClair CA. Facile High-Performance Liquid Chromatography Mass Spectrometry Method for Analysis of Cyclocreatine and Phosphocyclocreatine in Complex Mixtures of Amino Acids. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:7190-7196. [PMID: 31194545 PMCID: PMC7045947 DOI: 10.1021/acs.jafc.9b01878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Creatine transporter deficiency (CTD) is caused by a defect in the X-linked creatine transporter SLC6A8 gene leading to severe neurologic and physiologic conditions. Cyclocreatine and phosphocyclocreatine supplementation is seen as a potential treatment, but the presence of these compounds within commercially available dietary supplements presents the risk of self-medication. High-performance liquid chromatography-mass spectrometry (HPLC-MS) is an excellent technique to assess composition of complex amino acid mixtures. Herein, we have developed a facile HPLC-MS method using a cyano column in hydrophilic interaction liquid chromatography (HILIC) mode with isocratic elution over 4 min to identify the main components of two commercially available dietary supplements. The relative standard deviation (RSD) for retention time and extracted ion integrated area are <0.3% and 4%, respectively, showing excellent reproducibility. Cyclocreatine and phosphocyclocreatine were not detectable within the dietary supplements, even at ppm levels, demonstrating the power and importance of the developed HPLC-MS method in analyzing complex mixtures.
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Affiliation(s)
- Dingyin Tao
- Corresponding authors: Dr. Dingyin Tao,
; and Dr. Christopher A. LeClair,
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Abstract
With an ever aging population, identifying interventions that can alleviate age-related functional declines has become increasingly important. Dietary supplements have taken center stage based on various health claims and have become a multi-million dollar business. One such supplement is creatine, a major contributor to normal cellular physiology. Creatine, an energy source that can be endogenously synthesized or obtained through diet and supplement, is involved primarily in cellular metabolism via ATP replenishment. The goal of this chapter is to summarize how creatine and its associated enzyme, creatine kinase, act under normal physiological conditions, and how altered levels of either may lead to detrimental functional outcomes. Furthermore, we will focus on the effect of aging on the creatine system and how supplementation may affect the aging process and perhaps reverse it.
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Affiliation(s)
- Nathalie Sumien
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Ritu A Shetty
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Eric B Gonzales
- Department of Medical Education, TCU and UNTHSC School of Medicine, Fort Worth, TX, USA.
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Giusti L, Molinaro A, Alessandrì MG, Boldrini C, Ciregia F, Lacerenza S, Ronci M, Urbani A, Cioni G, Mazzoni MR, Pizzorusso T, Lucacchini A, Baroncelli L. Brain mitochondrial proteome alteration driven by creatine deficiency suggests novel therapeutic venues for creatine deficiency syndromes. Neuroscience 2019; 409:276-289. [PMID: 31029731 DOI: 10.1016/j.neuroscience.2019.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/09/2019] [Accepted: 03/12/2019] [Indexed: 01/15/2023]
Abstract
Creatine (Cr) is a small metabolite with a central role in energy metabolism and mitochondrial function. Creatine deficiency syndromes are inborn errors of Cr metabolism causing Cr depletion in all body tissues and particularly in the nervous system. Patient symptoms involve intellectual disability, language and behavioral disturbances, seizures and movement disorders suggesting that brain cells are particularly sensitive to Cr depletion. Cr deficiency was found to affect metabolic activity and structural abnormalities of mitochondrial organelles; however a detailed analysis of molecular mechanisms linking Cr deficit, energy metabolism alterations and brain dysfunction is still missing. Using a proteomic approach we evaluated the proteome changes of the brain mitochondrial fraction induced by the deletion of the Cr transporter (CrT) in developing mutant mice. We found a marked alteration of the mitochondrial proteomic landscape in the brain of CrT deficient mice, with the overexpression of many proteins involved in energy metabolism and response to oxidative stress. Moreover, our data suggest possible abnormalities of dendritic spines, synaptic function and plasticity, network excitability and neuroinflammatory response. Intriguingly, the alterations occurred in coincidence with the developmental onset of neurological symptoms. Thus, cerebral mitochondrial alterations could represent an early response to Cr deficiency that could be targeted for therapeutic intervention.
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Affiliation(s)
- Laura Giusti
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy; School of Pharmacy, University of Camerino, I-62032 Camerino, Italy
| | - Angelo Molinaro
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135, Florence, Italy; Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy
| | - Claudia Boldrini
- Department of Pharmacy, University of Pisa, I-56126, Pisa, Italy
| | - Federica Ciregia
- Department of Pharmacy, University of Pisa, I-56126, Pisa, Italy; Department of Rheumatology, GIGA Research, Centre Hospitalier Universitaire (CHU) de Liège, B-4000, Liège, Belgium
| | - Serena Lacerenza
- Department of Pharmacy, University of Pisa, I-56126, Pisa, Italy
| | - Maurizio Ronci
- Department of Medical, Oral and Biotechnological Sciences, University G. d'Annunzio of Chieti-Pescara, I-66100, Chieti, Italy
| | - Andrea Urbani
- Institute of Biochemistry and Clinical Chemistry, Catholic university of the sacred heart, I-00168, Rome, Italy
| | - Giovanni Cioni
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy; Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy
| | | | - Tommaso Pizzorusso
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135, Florence, Italy; Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy
| | - Antonio Lucacchini
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy; Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy.
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Balestrino M, Adriano E. Beyond sports: Efficacy and safety of creatine supplementation in pathological or paraphysiological conditions of brain and muscle. Med Res Rev 2019; 39:2427-2459. [PMID: 31012130 DOI: 10.1002/med.21590] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 03/26/2019] [Accepted: 04/02/2019] [Indexed: 01/16/2023]
Abstract
Creatine is pivotal in energy metabolism of muscle and brain cells, both in physiological and in pathological conditions. Additionally, creatine facilitates the differentiation of muscle and neuronal cells. Evidence of effectiveness of creatine supplementation in improving several clinical conditions is now substantial, and we review it in this paper. In hereditary diseases where its synthesis is impaired, creatine has a disease-modifying capacity, especially when started soon after birth. Strong evidence, including a Cochrane meta-analysis, shows that it improves muscular strength and general well-being in muscular dystrophies. Significant evidence exists also of its effectiveness in secondary prevention of statin myopathy and of treatment-resistant depression in women. Vegetarians and vegans do not consume any dietary creatine and must synthesize all they need, spending most of their methylation capacity. Nevertheless, they have a lower muscular concentration of creatine. Creatine supplementation has proved effective in increasing muscular and neuropsychological performance in vegetarians or vegans and should, therefore, be recommended especially in those of them who are athletes, heavy-duty laborers or who undergo intense mental effort. Convincing evidence also exists of creatine effectiveness in muscular atrophy and sarcopenia in the elderly, and in brain energy shortage (mental fatigue, sleep deprivation, environmental hypoxia as in mountain climbing, and advanced age). Furthermore, we review more randomized, placebo-controlled trials showing that creatine supplementation is safe up to 20 g/d, with a possible caveat only in people with kidney disease. We trust that the evidence we review will be translated into clinical practice and will spur more research on these subjects.
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Affiliation(s)
- Maurizio Balestrino
- Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili (DINOGMI), University of Genova, Genova, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Enrico Adriano
- Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili (DINOGMI), University of Genova, Genova, Italy
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Ito S. [Elucidation of Disease Mechanisms Based on Transport Function at Tissue Barriers and Challenges in Drug Development]. YAKUGAKU ZASSHI 2019; 139:497-503. [PMID: 30930376 DOI: 10.1248/yakushi.18-00153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tissue barriers contribute to the maintenance of homeostasis in the body, and tissue barrier dysfunction presents a risk factor for a variety of diseases. The blood-brain barrier (BBB) is a major tissue barrier acting as a static barrier and dynamic interface that plays an important role in the maintenance of central nervous system homeostasis. We show the functional characterization of the brain-to-blood efflux transport system of amyloid-β peptide (Aβ) across the BBB. We found that activated vitamin D3 may be a candidate agent for modulating the Aβ clearance across the BBB. Cerebral creatine deficiency syndromes are caused by loss-of-function mutations in the creatine transporter (CRT; SLC6A8), which transports creatine at the BBB. We found that functional impairment of CRT due to a G561R mutation resulted in incomplete N-linked glycosylation due to misfolding during protein maturation, leading to impaired creatine transport activity at the BBB. To develop a delivery system for biomedicine across the tissue barrier, we established a screening system to identify cell-penetrating peptides by a combination of in vitro cell permeability screening assays and phage display technology. Using this system, we identified cyclic hepta-peptides that are able to facilitate intestinal absorption of phages in vitro and in vivo, which are promising candidates as a carrier for macromolecular biomedicines. In conclusion, these studies focusing on the dynamic interface of tissue barriers will contribute to knowledge on disease pathogenesis as well as the development of a targeted biomedicine delivery system.
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Affiliation(s)
- Shingo Ito
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University
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Molinaro A, Alessandrì MG, Putignano E, Leuzzi V, Cioni G, Baroncelli L, Pizzorusso T. A Nervous System-Specific Model of Creatine Transporter Deficiency Recapitulates the Cognitive Endophenotype of the Disease: a Longitudinal Study. Sci Rep 2019; 9:62. [PMID: 30635645 PMCID: PMC6329805 DOI: 10.1038/s41598-018-37303-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 11/15/2018] [Indexed: 01/28/2023] Open
Abstract
Mutations in creatine (Cr) transporter (CrT) gene lead to cerebral creatine deficiency syndrome-1 (CTD), an orphan neurodevelopmental disorder presenting with brain Cr deficiency, intellectual disability, seizures, movement and autistic-like behavioral disturbances, language and speech impairment. We have recently generated a murine model of CTD obtained by ubiquitous deletion of 5-7 exons in the CrT gene. These mice showed a marked Cr depletion, associated to early and progressive cognitive impairment, and autistic-like defects, thus resembling the key features of human CTD. Given the importance of extraneural dysfunctions in neurodevelopmental disorders, here we analyzed the specific role of neural Cr in the CTD phenotype. We induced the conditional deletion of Slc6a8 gene in neuronal and glial cells by crossing CrT floxed mice with the Nestin::Cre recombinase Tg (Nes-cre) 1Kln mouse. We report that nervous system-specific Cr depletion leads to a progressive cognitive regression starting in the adult age. No autistic-like features, including repetitive and stereotyped movements, routines and rituals, are present in this model. These results indicate that Cr depletion in the nervous system is a pivotal cause of the CTD pathological phenotype, in particular with regard to the cognitive domain, but extraneural actors also play a role.
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Affiliation(s)
- Angelo Molinaro
- Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135, Florence, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128, Pisa, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy
| | - Vincenzo Leuzzi
- Department of Paediatrics, Child Neurology and Psychiatry, Sapienza University of Rome, I-00184, Rome, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy. .,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128, Pisa, Italy.
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135, Florence, Italy
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Wang Q, Yang J, Liu Y, Li X, Luo F, Xie J. A novel SLC6A8 mutation associated with intellectual disabilities in a Chinese family exhibiting creatine transporter deficiency: case report. BMC MEDICAL GENETICS 2018; 19:193. [PMID: 30400883 PMCID: PMC6219255 DOI: 10.1186/s12881-018-0707-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/22/2018] [Indexed: 12/19/2022]
Abstract
Background X-linked creatine transporter deficiency (OMIM#300036,CRTR-D) is characterized by cerebral creatine deficiency, intellectual disabilities, severe speech impairment, seizures and behavioral problems. Mutations in the creatine transporter gene SLC6A8, a member of the solute-carrier family 6 mapped to Xq28, have been reported to cause the creatine transporter deficiency. Case presentation The proband presented at 5 yrs. 1 month of age with delays in intellectual and development, seizures and behavioral problems. A novel missense mutation, c.1181C > A (p.Thr394Lys), in the SLC6A8 gene (NM_005629.3) was detected via targeted exome sequencing, and then validated by Sanger sequencing. Multiple in silico variant effect analysis methods, including SIFT, PolyPhen2, PROVEAN, and Mutation Taster predicted that this variant was likely damaging or diseasing-causing. This hemizygous variation was also identified in the affected brother with the same clinical condition and inherited from the heterozygous carrier mother. The diagnosis was suggested by increased urinary creatine/creatinine (Cr:Crn) ratio and markedly reduced creatine content peak by brain proton magnetic resonance spectroscopy (MRS). The proband’s mother became pregnant with a 3rd sibling, in whom the Sanger sequencing result of c.1181C > A was negative. Conclusion The novel mutation c.1181C > A in the SLC6A8 gene reported in a Chinese family has expanded the mutation spectrum of CRTR-D. The combination of powerful new technologies such as targeted exome sequencing with thorough systematic clinical evaluation of patients will improve the diagnostic yield, and assist in genetic counselling and prenatal diagnosis for suspected genetic disorders. Electronic supplementary material The online version of this article (10.1186/s12881-018-0707-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qin Wang
- Shenzhen Maternity and Child Healthcare Hospital, No. 3012, Fuqiang Road, Shenzhen, 518028, Guangdong, China
| | - Jingxin Yang
- Shenzhen Maternity and Child Healthcare Hospital, No. 3012, Fuqiang Road, Shenzhen, 518028, Guangdong, China
| | - Yang Liu
- Shenzhen Maternity and Child Healthcare Hospital, No. 3012, Fuqiang Road, Shenzhen, 518028, Guangdong, China
| | - Xingping Li
- Shenzhen Maternity and Child Healthcare Hospital, No. 3012, Fuqiang Road, Shenzhen, 518028, Guangdong, China
| | - Fuwei Luo
- Shenzhen Maternity and Child Healthcare Hospital, No. 3012, Fuqiang Road, Shenzhen, 518028, Guangdong, China
| | - Jiansheng Xie
- Shenzhen Maternity and Child Healthcare Hospital, No. 3012, Fuqiang Road, Shenzhen, 518028, Guangdong, China.
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Stockebrand M, Sasani A, Das D, Hornig S, Hermans-Borgmeyer I, Lake HA, Isbrandt D, Lygate CA, Heerschap A, Neu A, Choe CU. A Mouse Model of Creatine Transporter Deficiency Reveals Impaired Motor Function and Muscle Energy Metabolism. Front Physiol 2018; 9:773. [PMID: 30013483 PMCID: PMC6036259 DOI: 10.3389/fphys.2018.00773] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/04/2018] [Indexed: 11/22/2022] Open
Abstract
Creatine serves as fast energy buffer in organs of high-energy demand such as brain and skeletal muscle. L-Arginine:glycine amidinotransferase (AGAT) and guanidinoacetate N-methyltransferase are responsible for endogenous creatine synthesis. Subsequent uptake into target organs like skeletal muscle, heart and brain is mediated by the creatine transporter (CT1, SLC6A8). Creatine deficiency syndromes are caused by defects of endogenous creatine synthesis or transport and are mainly characterized by intellectual disability, behavioral abnormalities, poorly developed muscle mass, and in some cases also muscle weakness. CT1-deficiency is estimated to be among the most common causes of X-linked intellectual disability and therefore the brain phenotype was the main focus of recent research. Unfortunately, very limited data concerning muscle creatine levels and functions are available from patients with CT1 deficiency. Furthermore, different CT1-deficient mouse models yielded conflicting results and detailed analyses of their muscular phenotype are lacking. Here, we report the generation of a novel CT1-deficient mouse model and characterized the effects of creatine depletion in skeletal muscle. HPLC-analysis showed strongly reduced total creatine levels in skeletal muscle and heart. MR-spectroscopy revealed an almost complete absence of phosphocreatine in skeletal muscle. Increased AGAT expression in skeletal muscle was not sufficient to compensate for insufficient creatine transport. CT1-deficient mice displayed profound impairment of skeletal muscle function and morphology (i.e., reduced strength, reduced endurance, and muscle atrophy). Furthermore, severely altered energy homeostasis was evident on magnetic resonance spectroscopy. Strongly reduced phosphocreatine resulted in decreased ATP/Pi levels despite an increased inorganic phosphate to ATP flux. Concerning glucose metabolism, we show increased glucose transporter type 4 expression in muscle and improved glucose clearance in CT1-deficient mice. These metabolic changes were associated with activation of AMP-activated protein kinase – a central regulator of energy homeostasis. In summary, creatine transporter deficiency resulted in a severe muscle weakness and atrophy despite different compensatory mechanisms.
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Affiliation(s)
- Malte Stockebrand
- German Center for Neurodegenerative Diseases, Bonn, Germany.,Institute for Molecular and Behavioral Neuroscience, University of Cologne, Cologne, Germany
| | - Ali Sasani
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Experimental Neuropediatrics, Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Devashish Das
- Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Sönke Hornig
- Experimental Neuropediatrics, Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Irm Hermans-Borgmeyer
- Transgenic Mouse Unit, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hannah A Lake
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom.,Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Dirk Isbrandt
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Craig A Lygate
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom.,Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Arend Heerschap
- Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Axel Neu
- Experimental Neuropediatrics, Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Chi-Un Choe
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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49
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Bruun TUJ, Sidky S, Bandeira AO, Debray FG, Ficicioglu C, Goldstein J, Joost K, Koeberl DD, Luísa D, Nassogne MC, O'Sullivan S, Õunap K, Schulze A, van Maldergem L, Salomons GS, Mercimek-Andrews S. Treatment outcome of creatine transporter deficiency: international retrospective cohort study. Metab Brain Dis 2018; 33:875-884. [PMID: 29435807 DOI: 10.1007/s11011-018-0197-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 01/29/2018] [Indexed: 12/25/2022]
Abstract
To evaluate the outcome of current treatment for creatine transporter (CRTR) deficiency, we developed a clinical severity score and initiated an international treatment registry. An online questionnaire was completed by physicians following patients with CRTR deficiency on a treatment, including creatine and/or arginine, and/or glycine. Clinical severity score included 1) global developmental delay/intellectual disability; 2) seizures; 3) behavioural disorder. Phenotype scored 1-3 = mild; 4-6 = moderate; and 7-9 = severe. We applied the clinical severity score pre- and on-treatment. Seventeen patients, 14 males and 3 females, from 16 families were included. Four patients had severe, 6 patients had moderate, and 7 patients had a mild phenotype. The phenotype ranged from mild to severe in patients diagnosed at or before 2 years of age or older than 6 years of age. The phenotype ranged from mild to severe in patients with mildly elevated urine creatine to creatinine ratio. Fourteen patients were on the combined creatine, arginine and glycine therapy. On the combined treatment with creatine, arginine and glycine, none of the males showed either deterioration or improvements in their clinical severity score, whereas two females showed improvements in the clinical severity score. Creatine monotherapy resulted in deterioration of the clinical severity score in one male. There seems to be no correlation between phenotype and degree of elevation in urine creatine to creatinine ratio, genotype, or age at diagnosis. Combined creatine, arginine and glycine therapy might have stopped disease progression in males and improved phenotype in females.
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Affiliation(s)
- Theodora U J Bruun
- Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Sarah Sidky
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada
| | - Anabela O Bandeira
- Pediatrics, Metabolic Unit, Centro Materno Infantil do Norte, Centro Hospitalar do Porto, Porto, Portugal
| | | | - Can Ficicioglu
- Department of Pediatrics, Division of Human Genetics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer Goldstein
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, NC, North, USA
| | - Kairit Joost
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Dwight D Koeberl
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, NC, North, USA
| | - Diogo Luísa
- Metabolic Unit - Child Development Center, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
| | - Marie-Cecile Nassogne
- Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Woluwe-Saint-Lambert, Belgium
| | - Siobhan O'Sullivan
- Department of Metabolic Paediatrics, Royal Hospital for Sick Children, Belfast, UK
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Andreas Schulze
- Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada
- Departments of Paediatrics and Biochemistry, University of Toronto, Toronto, ON, Canada
| | | | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Saadet Mercimek-Andrews
- Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.
- Institute of Medical Sciences, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.
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50
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Sklirou E, Lichter-Konecki U. Inborn Errors of Metabolism with Cognitive Impairment: Metabolism Defects of Phenylalanine, Homocysteine and Methionine, Purine and Pyrimidine, and Creatine. Pediatr Clin North Am 2018; 65:267-277. [PMID: 29502913 DOI: 10.1016/j.pcl.2017.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Phenylketonuria is a defect in phenylalanine metabolism resulting in the excretion of phenylketones and severe intellectual disability. The principle of eliminating the offending amino acid from the diet as a successful treatment strategy was demonstrated. The development of a low methionine diet to treat homocystinuria was established after identifying the transsulfuration pathway resulting in cysteine synthesis. Both conditions are examples of disorders of amino acid metabolism. Lesch-Nyhan syndrome, a rare disorder of purine metabolism resulting in intellectual disability and self-injurious behavior, is a classical inborn error of metabolism. Disorders of creatine biosynthesis are relatively newly described and less known diseases.
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Affiliation(s)
- Evgenia Sklirou
- Division of Medical Genetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh, UPMC, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Uta Lichter-Konecki
- Division of Medical Genetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh, UPMC, 4401 Penn Avenue, Pittsburgh, PA 15224, USA.
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