1
|
Bucher ML, Dunn AR, Bradner JM, Egerton KS, Burkett JP, Johnson MA, Miller GW. Synaptic vesicle glycoprotein 2C enhances vesicular storage of dopamine and counters dopaminergic toxicity. Eur J Neurosci 2024; 59:2483-2501. [PMID: 38532289 DOI: 10.1111/ejn.16311] [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: 06/20/2023] [Revised: 02/14/2024] [Accepted: 02/22/2024] [Indexed: 03/28/2024]
Abstract
Dopaminergic neurons of the substantia nigra exist in a persistent state of vulnerability resulting from high baseline oxidative stress, high-energy demand, and broad unmyelinated axonal arborisations. Impairments in the storage of dopamine compound this stress because of cytosolic reactions that transform the vital neurotransmitter into an endogenous neurotoxicant, and this toxicity is thought to contribute to the dopamine neuron degeneration that occurs Parkinson's disease. We have previously identified synaptic vesicle glycoprotein 2C (SV2C) as a modifier of vesicular dopamine function, demonstrating that genetic ablation of SV2C in mice results in decreased dopamine content and evoked dopamine release in the striatum. Here, we adapted a previously published in vitro assay utilising false fluorescent neurotransmitter 206 (FFN206) to visualise how SV2C regulates vesicular dopamine dynamics and determined that SV2C promotes the uptake and retention of FFN206 within vesicles. In addition, we present data indicating that SV2C enhances the retention of dopamine in the vesicular compartment with radiolabelled dopamine in vesicles isolated from immortalised cells and from mouse brain. Further, we demonstrate that SV2C enhances the ability of vesicles to store the neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) and that genetic ablation of SV2C results in enhanced 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced vulnerability in mice. Together, these findings suggest that SV2C functions to enhance vesicular storage of dopamine and neurotoxicants and helps maintain the integrity of dopaminergic neurons.
Collapse
Affiliation(s)
- Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Amy R Dunn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- The Jackson Laboratory, Bar Harbor, Maine, USA
| | - Joshua M Bradner
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- AbbVie CRC, Cambridge, Massachusetts, USA
| | - Kristen Stout Egerton
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- School of Education and Health Sciences, North Central College, Naperville, Illinois, USA
| | - James P Burkett
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Michelle A Johnson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- College of Arts and Sciences, Oberlin College, Oberlin, Ohio, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| |
Collapse
|
2
|
Thöny B, Ng J, Kurian MA, Mills P, Martinez A. Mouse models for inherited monoamine neurotransmitter disorders. J Inherit Metab Dis 2024; 47:533-550. [PMID: 38168036 DOI: 10.1002/jimd.12710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/07/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
Several mouse models have been developed to study human defects of primary and secondary inherited monoamine neurotransmitter disorders (iMND). As the field continues to expand, current defects in corresponding mouse models include enzymes and a molecular co-chaperone involved in monoamine synthesis and metabolism (PAH, TH, PITX3, AADC, DBH, MAOA, DNAJC6), tetrahydrobiopterin (BH4) cofactor synthesis and recycling (adGTPCH1/DRD, arGTPCH1, PTPS, SR, DHPR), and vitamin B6 cofactor deficiency (ALDH7A1), as well as defective monoamine neurotransmitter packaging (VMAT1, VMAT2) and reuptake (DAT). No mouse models are available for human DNAJC12 co-chaperone and PNPO-B6 deficiencies, disorders associated with recessive variants that result in decreased stability and function of the aromatic amino acid hydroxylases and decreased neurotransmitter synthesis, respectively. More than one mutant mouse is available for some of these defects, which is invaluable as different variant-specific (knock-in) models may provide more insights into underlying mechanisms of disorders, while complete gene inactivation (knock-out) models often have limitations in terms of recapitulating complex human diseases. While these mouse models have common phenotypic traits also observed in patients, reflecting the defective homeostasis of the monoamine neurotransmitter pathways, they also present with disease-specific manifestations with toxic accumulation or deficiency of specific metabolites related to the specific gene affected. This review provides an overview of the currently available models and may give directions toward selecting existing models or generating new ones to investigate novel pathogenic mechanisms and precision therapies.
Collapse
Affiliation(s)
- Beat Thöny
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zürich, Switzerland
| | - Joanne Ng
- Genetic Therapy Accelerator Centre, University College London, Queen Square Institute of Neurology, London, UK
| | - Manju A Kurian
- Zayed Centre for Research into Rare Disease in Children, GOS Institute of Child Health, University College London, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Philippa Mills
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Aurora Martinez
- Department of Biomedicine and Center for Translational Research in Parkinson's Disease, University of Bergen, Bergen, Norway
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
3
|
Almuqbil MA, Tabassum S, Muthaffar OY, Ghamdi F, Al Masseri Z, Alsaman A, Alkhater RA. Parkinsonism-dystonia-2: Case-series study from Saudi Arabia. Ann Clin Transl Neurol 2024; 11:1063-1066. [PMID: 38389300 PMCID: PMC11021621 DOI: 10.1002/acn3.52020] [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: 08/15/2023] [Revised: 01/11/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Parkinsonism-dystonia-2 PKDYS2 is an autosomal-recessive disorder, caused by pathogenic biallelic variants in SLC18A2 which encodes the vesicular monoamine transporter (VMAT2) protein. PKDYS2 is a treatable neurotransmitter disease, and the rate of diagnosis of this disorder has increased significantly with the advance of genomic technologies. Our report highlights a novel pathologic variant in one case and a novel finding on MRI Brain, consisting of a normal symmetrical signal intensity in the dorsal brainstem and pons, and it substantiates the significance of genetic testing in the evaluation of children with developmental delays, which influences clinical decisions to enhance patient outcomes.
Collapse
Affiliation(s)
- Mohammed A. Almuqbil
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences (KSAU‐HS)RiyadhSaudi Arabia
- Division of Pediatric NeurologyKing Abdullah Specialist Children's Hospital (KASCH), National Guard Health Affairs (NGHA)RiyadhSaudi Arabia
- King Abdullah International Medical Center (KAIMRC), Ministry of National GuardRiyadhSaudi Arabia
| | - Sadia Tabassum
- Department of PediatricsKing Fahad Medical City (KFMC)RiyadhSaudi Arabia
| | - Osama Y. Muthaffar
- Department of Pediatrics, Faculty of MedicineKing Abdulaziz UniversityJeddahSaudi Arabia
| | - Fouad Ghamdi
- Department of Pediatric Neurology, Neuroscience CenterKing Fahad Specialist HospitalDammamSaudi Arabia
| | - Zainab Al Masseri
- Department of Pediatric, Medical Genetics UnitQatif Central Hospital, Eastern Health Cluster, Ministry of HealthQatifSaudi Arabia
| | - Abdulaziz Alsaman
- Department of Pediatric NeurologyNational Neuroscience Institute, King Fahad Medical City (KFMC)RiyadhSaudi Arabia
| | - Reem A. Alkhater
- Women and Child Institute, John's Hopkins Aramco Healthcare (Jhah)DhahranSaudi Arabia
- John's Hopkins School of MedicineBaltimoreUSA
- King Abdullah University for Science and Technology (KAUST)ThuwalSaudi Arabia
| |
Collapse
|
4
|
Abstract
The vesicular monoamine transporter 2 (VMAT2) is a proton-dependent antiporter responsible for loading monoamine neurotransmitters into synaptic vesicles. Dysregulation of VMAT2 can lead to several neuropsychiatric disorders including Parkinson's disease and schizophrenia. Furthermore, drugs such as amphetamine and MDMA are known to act on VMAT2, exemplifying its role in the mechanisms of actions for drugs of abuse. Despite VMAT2's importance, there remains a critical lack of mechanistic understanding, largely driven by a lack of structural information. Here, we report a 3.1 Å resolution cryo-electron microscopy (cryo-EM) structure of VMAT2 complexed with tetrabenazine (TBZ), a non-competitive inhibitor used in the treatment of Huntington's chorea. We find TBZ interacts with residues in a central binding site, locking VMAT2 in an occluded conformation and providing a mechanistic basis for non-competitive inhibition. We further identify residues critical for cytosolic and lumenal gating, including a cluster of hydrophobic residues which are involved in a lumenal gating strategy. Our structure also highlights three distinct polar networks that may determine VMAT2 conformational dynamics and play a role in proton transduction. The structure elucidates mechanisms of VMAT2 inhibition and transport, providing insights into VMAT2 architecture, function, and the design of small-molecule therapeutics.
Collapse
Affiliation(s)
- Michael P Dalton
- Department of Structural Biology, University of PittsburghPittsburghUnited States
| | - Mary Hongying Cheng
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook UniversityStony BrookUnited States
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook UniversityStony BrookUnited States
| | - Jonathan A Coleman
- Department of Structural Biology, University of PittsburghPittsburghUnited States
| |
Collapse
|
5
|
Calame DG, Wong JH, Panda P, Nguyen DT, Leong NC, Sangermano R, Patankar SG, Abdel-Hamid M, AlAbdi L, Safwat S, Flannery KP, Dardas Z, Fatih JM, Murali C, Kannan V, Lotze TE, Herman I, Ammouri F, Rezich B, Efthymiou S, Alavi S, Murphy D, Firoozfar Z, Nasab ME, Bahreini A, Ghasemi M, Haridy NA, Goldouzi HR, Eghbal F, Karimiani EG, Srinivasan VM, Gowda VK, Du H, Jhangiani SN, Coban-Akdemir Z, Marafi D, Rodan L, Isikay S, Rosenfeld JA, Ramanathan S, Staton M, Kerby C. Oberg, Clark RD, Wenman C, Loughlin S, Saad R, Ashraf T, Male A, Tadros S, Boostani R, Abdel-Salam GM, Zaki M, Abdalla E, Manzini MC, Pehlivan D, Posey JE, Gibbs RA, Houlden H, Alkuraya FS, Bujakowska K, Maroofian R, Lupski JR, Nguyen LN. Biallelic variation in the choline and ethanolamine transporter FLVCR1 underlies a pleiotropic disease spectrum from adult neurodegeneration to severe developmental disorders. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.02.09.24302464. [PMID: 38405817 PMCID: PMC10888986 DOI: 10.1101/2024.02.09.24302464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
FLVCR1 encodes Feline leukemia virus subgroup C receptor 1 (FLVCR1), a solute carrier (SLC) transporter within the Major Facilitator Superfamily. FLVCR1 is a widely expressed transmembrane protein with plasma membrane and mitochondrial isoforms implicated in heme, choline, and ethanolamine transport. While Flvcr1 knockout mice die in utero with skeletal malformations and defective erythropoiesis reminiscent of Diamond-Blackfan anemia, rare biallelic pathogenic FLVCR1 variants are linked to childhood or adult-onset neurodegeneration of the retina, spinal cord, and peripheral nervous system. We ascertained from research and clinical exome sequencing 27 individuals from 20 unrelated families with biallelic ultra-rare missense and predicted loss-of-function (pLoF) FLVCR1 variant alleles. We characterize an expansive FLVCR1 phenotypic spectrum ranging from adult-onset retinitis pigmentosa to severe developmental disorders with microcephaly, reduced brain volume, epilepsy, spasticity, and premature death. The most severely affected individuals, including three individuals with homozygous pLoF variants, share traits with Flvcr1 knockout mice and Diamond-Blackfan anemia including macrocytic anemia and congenital skeletal malformations. Pathogenic FLVCR1 missense variants primarily lie within transmembrane domains and reduce choline and ethanolamine transport activity compared with wild-type FLVCR1 with minimal impact on FLVCR1 stability or subcellular localization. Several variants disrupt splicing in a mini-gene assay which may contribute to genotype-phenotype correlations. Taken together, these data support an allele-specific gene dosage model in which phenotypic severity reflects residual FLVCR1 activity. This study expands our understanding of Mendelian disorders of choline and ethanolamine transport and demonstrates the importance of choline and ethanolamine in neurodevelopment and neuronal homeostasis.
Collapse
Affiliation(s)
- Daniel G. Calame
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jovi Huixin Wong
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Puravi Panda
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Dat Tuan Nguyen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Nancy C.P. Leong
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Riccardo Sangermano
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA
| | - Sohil G. Patankar
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA
| | - Mohamed Abdel-Hamid
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Lama AlAbdi
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sylvia Safwat
- Department of Genetics, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Kyle P. Flannery
- Department of Neuroscience and Cell Biology, Rutgers-Robert Wood Johnson Medical School, Child Health Institute of New Jersey, NY, USA
| | - Zain Dardas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jawid M. Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Chaya Murali
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Varun Kannan
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Timothy E. Lotze
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Isabella Herman
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Boys Town National Research Hospital, Boys Town, NE, USA
| | - Farah Ammouri
- Boys Town National Research Hospital, Boys Town, NE, USA
- The University of Kansas Health System, Westwood, KS, USA
| | - Brianna Rezich
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, NE, USA
| | - Stephanie Efthymiou
- Department of Neuromuscular diseases, UCL Institute of Neurology, WC1N 3BG, London, UK
| | - Shahryar Alavi
- Department of Neuromuscular diseases, UCL Institute of Neurology, WC1N 3BG, London, UK
| | - David Murphy
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, United Kingdom
| | | | | | - Amir Bahreini
- KaryoGen, Isfahan, Iran
- Department of Human Genetics, University of Pittsburgh, PA, USA
| | - Majid Ghasemi
- Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Hamid Reza Goldouzi
- Department of Pediatrics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Eghbal
- Department of Medical Genetics, Next Generation Genetic Polyclinic, Mashhad, Iran
| | - Ehsan Ghayoor Karimiani
- Molecular and Clinical Sciences Institute, St George’s, University of London, Cranmer Terrace London, London, UK
| | | | - Vykuntaraju K. Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | - Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | | | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Pediatrics, Faculty of Medicine, Kuwait University, Kuwait
| | - Lance Rodan
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Sedat Isikay
- Gaziantep Islam Science and Technology University, Medical Faculty, Department of Pediatric Neurology, Gaziantep, Turkey
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Baylor Genetics Laboratories, Houston, TX, USA
| | - Subhadra Ramanathan
- Division of Genetics, Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Michael Staton
- Division of Genetics, Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Kerby C. Oberg
- Department of Pathology and Human Anatomy, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Robin D. Clark
- Division of Genetics, Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Catharina Wenman
- Rare & Inherited Disease Laboratory, NHS North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3BH, UK
| | - Sam Loughlin
- Rare & Inherited Disease Laboratory, NHS North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3BH, UK
| | - Ramy Saad
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Tazeen Ashraf
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Alison Male
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Shereen Tadros
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Reza Boostani
- Department of Neurology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ghada M.H. Abdel-Salam
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Maha Zaki
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Ebtesam Abdalla
- Department of Genetics, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - M. Chiara Manzini
- Department of Neuroscience and Cell Biology, Rutgers-Robert Wood Johnson Medical School, Child Health Institute of New Jersey, NY, USA
| | - Davut Pehlivan
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jennifer E. Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Richard A. Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Henry Houlden
- Department of Neuromuscular diseases, UCL Institute of Neurology, WC1N 3BG, London, UK
| | - Fowzan S. Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Kinga Bujakowska
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA
| | - Reza Maroofian
- Department of Neuromuscular diseases, UCL Institute of Neurology, WC1N 3BG, London, UK
| | - James R. Lupski
- Texas Children’s Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Long Nam Nguyen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
- Immunology Program, Life Sciences Institute, National University of Singapore, Singapore 117456
- Singapore Lipidomics Incubator (SLING), Life Sciences Institute, National University of Singapore, Singapore 117456
- Cardiovascular Disease Research (CVD) Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
| |
Collapse
|
6
|
Dalton MP, Cheng MH, Bahar I, Coleman JA. Structural mechanisms for VMAT2 inhibition by tetrabenazine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.05.556211. [PMID: 37732203 PMCID: PMC10508774 DOI: 10.1101/2023.09.05.556211] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The vesicular monoamine transporter 2 (VMAT2) is a proton-dependent antiporter responsible for loading monoamine neurotransmitters into synaptic vesicles. Dysregulation of VMAT2 can lead to several neuropsychiatric disorders including Parkinson's disease and schizophrenia. Furthermore, drugs such as amphetamine and MDMA are known to act on VMAT2, exemplifying its role in the mechanisms of actions for drugs of abuse. Despite VMAT2's importance, there remains a critical lack of mechanistic understanding, largely driven by a lack of structural information. Here we report a 3.1 Å resolution cryo-EM structure of VMAT2 complexed with tetrabenazine (TBZ), a non-competitive inhibitor used in the treatment of Huntington's chorea. We find TBZ interacts with residues in a central binding site, locking VMAT2 in an occluded conformation and providing a mechanistic basis for non-competitive inhibition. We further identify residues critical for cytosolic and lumenal gating, including a cluster of hydrophobic residues which are involved in a lumenal gating strategy. Our structure also highlights three distinct polar networks that may determine VMAT2 conformational dynamics and play a role in proton transduction. The structure elucidates mechanisms of VMAT2 inhibition and transport, providing insights into VMAT2 architecture, function, and the design of small-molecule therapeutics.
Collapse
Affiliation(s)
- Michael P Dalton
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Mary Hongying Cheng
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jonathan A Coleman
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| |
Collapse
|
7
|
Wang Y, Zhang P, Chao Y, Zhu Z, Yang C, Zhou Z, Li Y, Long Y, Liu Y, Li D, Wang S, Qu Q. Transport and inhibition mechanism for VMAT2-mediated synaptic vesicle loading of monoamines. Cell Res 2024; 34:47-57. [PMID: 38163846 PMCID: PMC10770148 DOI: 10.1038/s41422-023-00906-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 11/21/2023] [Indexed: 01/03/2024] Open
Abstract
Monoamine neurotransmitters such as serotonin and dopamine are loaded by vesicular monoamine transporter 2 (VMAT2) into synaptic vesicles for storage and subsequent release in neurons. Impaired VMAT2 function underlies various neuropsychiatric diseases. VMAT2 inhibitors reserpine and tetrabenazine are used to treat hypertension, movement disorders associated with Huntington's Disease and Tardive Dyskinesia. Despite its physiological and pharmacological significance, the structural basis underlying VMAT2 substrate recognition and its inhibition by various inhibitors remains unknown. Here we present cryo-EM structures of human apo VMAT2 in addition to states bound to serotonin, tetrabenazine, and reserpine. These structures collectively capture three states, namely the lumen-facing, occluded, and cytosol-facing conformations. Notably, tetrabenazine induces a substantial rearrangement of TM2 and TM7, extending beyond the typical rocker-switch movement. These functionally dynamic snapshots, complemented by biochemical analysis, unveil the essential components responsible for ligand recognition, elucidate the proton-driven exchange cycle, and provide a framework to design improved pharmaceutics targeting VMAT2.
Collapse
Affiliation(s)
- Yuwei Wang
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Pei Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecule Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Yulin Chao
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Zhini Zhu
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Chuanhui Yang
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Zixuan Zhou
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Yaohui Li
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Yonghui Long
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Yuehua Liu
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Dianfan Li
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecule Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Sheng Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecule Cell Science, Chinese Academy of Sciences, Shanghai, China.
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang, China.
| | - Qianhui Qu
- Shanghai Stomatological Hospital, School of Stomatology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Department of Systems Biology for Medicine, Fudan University, Shanghai, China.
| |
Collapse
|
8
|
Pidathala S, Liao S, Dai Y, Li X, Long C, Chang CL, Zhang Z, Lee CH. Mechanisms of neurotransmitter transport and drug inhibition in human VMAT2. Nature 2023; 623:1086-1092. [PMID: 37914936 DOI: 10.1038/s41586-023-06727-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/09/2023] [Indexed: 11/03/2023]
Abstract
Monoamine neurotransmitters such as dopamine and serotonin control important brain pathways, including movement, sleep, reward and mood1. Dysfunction of monoaminergic circuits has been implicated in various neurodegenerative and neuropsychiatric disorders2. Vesicular monoamine transporters (VMATs) pack monoamines into vesicles for synaptic release and are essential to neurotransmission3-5. VMATs are also therapeutic drug targets for a number of different conditions6-9. Despite the importance of these transporters, the mechanisms of substrate transport and drug inhibition of VMATs have remained elusive. Here we report cryo-electron microscopy structures of the human vesicular monoamine transporter VMAT2 in complex with the antichorea drug tetrabenazine, the antihypertensive drug reserpine or the substrate serotonin. Remarkably, the two drugs use completely distinct inhibition mechanisms. Tetrabenazine binds VMAT2 in a lumen-facing conformation, locking the luminal gating lid in an occluded state to arrest the transport cycle. By contrast, reserpine binds in a cytoplasm-facing conformation, expanding the vestibule and blocking substrate access. Structural analyses of VMAT2 also reveal the conformational changes following transporter isomerization that drive substrate transport into the vesicle. These findings provide a structural framework for understanding the physiology and pharmacology of neurotransmitter packaging by synaptic vesicular transporters.
Collapse
Affiliation(s)
- Shabareesh Pidathala
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Shuyun Liao
- State Key Laboratory of Membrane Biology, Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China
| | - Yaxin Dai
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Xiao Li
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Changkun Long
- State Key Laboratory of Membrane Biology, Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China
| | - Chi-Lun Chang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Zhe Zhang
- State Key Laboratory of Membrane Biology, Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China.
| | - Chia-Hsueh Lee
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
| |
Collapse
|
9
|
Wang X, Marmouzi I, Finnie PS, Støve SI, Bucher ML, Lipina TV, Ramsey AJ, Miller GW, Salahpour A. Tricyclic and tetracyclic antidepressants upregulate VMAT2 activity and rescue disease-causing VMAT2 variants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.09.561601. [PMID: 37873339 PMCID: PMC10592782 DOI: 10.1101/2023.10.09.561601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Vesicular monoamine transporter 2 (VMAT2) is an essential transporter that regulates brain monoamine transmission and is important for mood, cognition, motor activity, and stress regulation. However, VMAT2 remains underexplored as a pharmacological target. In this study, we report that tricyclic and tetracyclic antidepressants acutely inhibit, but persistently upregulate VMAT2 activity by promoting VMAT2 protein maturation. Importantly, the VMAT2 upregulation effect was greater in BE(2)-M17 cells that endogenously express VMAT2 as compared to a heterologous expression system (HEK293). The net sustained effect of tricyclics and tetracyclics is an upregulation of VMAT2 activity, despite their acute inhibitory effect. Furthermore, imipramine and mianserin, two representative compounds, also demonstrated rescue of nine VMAT2 variants that cause Brain Vesicular Monoamine Transport Disease (BVMTD). VMAT2 upregulation could be beneficial for disorders associated with reduced monoamine transmission, including mood disorders and BVMTD, a rare but often fatal condition caused by a lack of functional VMAT2. Our findings provide the first evidence that small molecules can upregulate VMAT2 and have potential therapeutic benefit for various neuropsychiatric conditions.
Collapse
|
10
|
van Eyk CL, Fahey MC, Gecz J. Redefining cerebral palsies as a diverse group of neurodevelopmental disorders with genetic aetiology. Nat Rev Neurol 2023; 19:542-555. [PMID: 37537278 DOI: 10.1038/s41582-023-00847-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2023] [Indexed: 08/05/2023]
Abstract
Cerebral palsy is a clinical descriptor covering a diverse group of permanent, non-degenerative disorders of motor function. Around one-third of cases have now been shown to have an underlying genetic aetiology, with the genetic landscape overlapping with those of neurodevelopmental disorders including intellectual disability, epilepsy, speech and language disorders and autism. Here we review the current state of genomic testing in cerebral palsy, highlighting the benefits for personalized medicine and the imperative to consider aetiology during clinical diagnosis. With earlier clinical diagnosis now possible, we emphasize the opportunity for comprehensive and early genomic testing as a crucial component of the routine diagnostic work-up in people with cerebral palsy.
Collapse
Affiliation(s)
- Clare L van Eyk
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
| | - Michael C Fahey
- Department of Paediatrics, Monash University, Melbourne, Victoria, Australia
| | - Jozef Gecz
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia.
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia.
- South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
| |
Collapse
|
11
|
Bucher ML, Dunn AR, Bradner JM, Egerton KS, Burkett JP, Johnson MA, Miller GW. Synaptic vesicle glycoprotein 2C enhances vesicular storage of dopamine and counters dopaminergic toxicity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546143. [PMID: 37425736 PMCID: PMC10326994 DOI: 10.1101/2023.06.26.546143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Dopaminergic neurons of the substantia nigra exist in a persistent state of vulnerability resulting from high baseline oxidative stress, high energy demand, and broad unmyelinated axonal arborizations. Impairments in the storage of dopamine compound this stress due to cytosolic reactions that transform the vital neurotransmitter into an endogenous neurotoxicant, and this toxicity is thought to contribute to the dopamine neuron degeneration that occurs Parkinson's disease. We have previously identified synaptic vesicle glycoprotein 2C (SV2C) as a modifier of vesicular dopamine function, demonstrating that genetic ablation of SV2C in mice results in decreased dopamine content and evoked dopamine release in the striatum. Here, we adapted a previously published in vitro assay utilizing false fluorescent neurotransmitter 206 (FFN206) to visualize how SV2C regulates vesicular dopamine dynamics and determined that SV2C promotes the uptake and retention of FFN206 within vesicles. In addition, we present data indicating that SV2C enhances the retention of dopamine in the vesicular compartment with radiolabeled dopamine in vesicles isolated from immortalized cells and from mouse brain. Further, we demonstrate that SV2C enhances the ability of vesicles to store the neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) and that genetic ablation of SV2C results in enhanced 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced vulnerability in mice. Together, these findings suggest that SV2C functions to enhance vesicular storage of dopamine and neurotoxicants, and helps maintain the integrity of dopaminergic neurons.
Collapse
Affiliation(s)
- Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Amy R Dunn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Joshua M Bradner
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Kristen Stout Egerton
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - James P Burkett
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Michelle A Johnson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10031, USA
| |
Collapse
|
12
|
Di Fonzo A, Jinnah HA, Zech M. Dystonia genes and their biological pathways. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:61-103. [PMID: 37482402 DOI: 10.1016/bs.irn.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
High-throughput sequencing has been instrumental in uncovering the spectrum of pathogenic genetic alterations that contribute to the etiology of dystonia. Despite the immense heterogeneity in monogenic causes, studies performed during the past few years have highlighted that many rare deleterious variants associated with dystonic presentations affect genes that have roles in certain conserved pathways in neural physiology. These various gene mutations that appear to converge towards the disruption of interconnected cellular networks were shown to produce a wide range of different dystonic disease phenotypes, including isolated and combined dystonias as well as numerous clinically complex, often neurodevelopmental disorder-related conditions that can manifest with dystonic features in the context of multisystem disturbances. In this chapter, we summarize the manifold dystonia-gene relationships based on their association with a discrete number of unifying pathophysiological mechanisms and molecular cascade abnormalities. The themes on which we focus comprise dopamine signaling, heavy metal accumulation and calcifications in the brain, nuclear envelope function and stress response, gene transcription control, energy homeostasis, lysosomal trafficking, calcium and ion channel-mediated signaling, synaptic transmission beyond dopamine pathways, extra- and intracellular structural organization, and protein synthesis and degradation. Enhancing knowledge about the concept of shared etiological pathways in the pathogenesis of dystonia will motivate clinicians and researchers to find more efficacious treatments that allow to reverse pathologies in patient-specific core molecular networks and connected multipathway loops.
Collapse
Affiliation(s)
- Alessio Di Fonzo
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - H A Jinnah
- Departments of Neurology, Human Genetics, and Pediatrics, Atlanta, GA, United States
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.
| |
Collapse
|
13
|
Mastrangelo M, Tolve M, Artiola C, Bove R, Carducci C, Carducci C, Angeloni A, Pisani F, Leuzzi V. Phenotypes and Genotypes of Inherited Disorders of Biogenic Amine Neurotransmitter Metabolism. Genes (Basel) 2023; 14:genes14020263. [PMID: 36833190 PMCID: PMC9957200 DOI: 10.3390/genes14020263] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Inherited disorders of biogenic amine metabolism are genetically determined conditions resulting in dysfunctions or lack of enzymes involved in the synthesis, degradation, or transport of dopamine, serotonin, adrenaline/noradrenaline, and their metabolites or defects of their cofactor or chaperone biosynthesis. They represent a group of treatable diseases presenting with complex patterns of movement disorders (dystonia, oculogyric crises, severe/hypokinetic syndrome, myoclonic jerks, and tremors) associated with a delay in the emergence of postural reactions, global development delay, and autonomic dysregulation. The earlier the disease manifests, the more severe and widespread the impaired motor functions. Diagnosis mainly depends on measuring neurotransmitter metabolites in cerebrospinal fluid that may address the genetic confirmation. Correlations between the severity of phenotypes and genotypes may vary remarkably among the different diseases. Traditional pharmacological strategies are not disease-modifying in most cases. Gene therapy has provided promising results in patients with DYT-DDC and in vitro models of DYT/PARK-SLC6A3. The rarity of these diseases, combined with limited knowledge of their clinical, biochemical, and molecular genetic features, frequently leads to misdiagnosis or significant diagnostic delays. This review provides updates on these aspects with a final outlook on future perspectives.
Collapse
Affiliation(s)
- Mario Mastrangelo
- Child Neurology and Psychiatry Unit, Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
| | - Manuela Tolve
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Cristiana Artiola
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Rossella Bove
- Child Neurology and Psychiatry Unit, Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Claudia Carducci
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Carla Carducci
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Antonio Angeloni
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Francesco Pisani
- Child Neurology and Psychiatry Unit, Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
- Correspondence: ; Tel.: +39-649972930; Fax: +39-64440232
| | - Vincenzo Leuzzi
- Child Neurology and Psychiatry Unit, Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
- Azienda Ospedaliero Universitaria Policlinico Umberto I, 00161 Rome, Italy
| |
Collapse
|