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Chen X, Qu H, Yao Q, Cai X, He T, Zhang X. Case report: Analysis of a gene variant and prenatal diagnosis in a family with megalencephalic leukoencephalopathy with subcortical cysts. Front Neurol 2023; 14:1253398. [PMID: 37928140 PMCID: PMC10622957 DOI: 10.3389/fneur.2023.1253398] [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: 07/05/2023] [Accepted: 09/18/2023] [Indexed: 11/07/2023] Open
Abstract
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare inherited cerebral white matter disorder in children. Pathogenic variations in the causative gene MLC1 are found in approximately 76% of patients and are inherited in an autosomal recessive manner. In this study, we identified an IVS2 + 1delG variant in MLC1 in the firstborn girl of a pregnant woman who has the clinical features of MLC, including macrocephaly, motor development delay, progressive functional deterioration, and myelinopathy, whereas no obvious subcortical cysts were observed by magnetic resonance imaging of the brain. The proband is homozygous for the IVS2 + 1delG mutation, which was inherited from the parents. This variant disrupts the donor splice site, causing an abnormal transcript that results in a premature termination codon and produces a truncated protein, which was confirmed to affect splicing by MLC1 cDNA analysis. This variant was also detected in family members, and a prenatal diagnosis for the fetus was undertaken. Eventually, the couple gave birth to an unaffected baby. Furthermore, we conducted a long-term follow-up of the proband's clinical course. This report improves our understanding of the genetic and phenotypic characteristics of MLC and provides a new genetic basis for prenatal diagnosis and genetic counseling.
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Affiliation(s)
- Xi Chen
- Department of Medical Genetics and Prenatal Diagnosis Center, West China Second University Hospital, Sichuan University, Chengdu, China
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Haibo Qu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
- Department of Radiology, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Qiang Yao
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Xiaotang Cai
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
- Department of Rehabilitation, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Tiantian He
- Department of Medical Genetics and Prenatal Diagnosis Center, West China Second University Hospital, Sichuan University, Chengdu, China
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Xuemei Zhang
- Department of Medical Genetics and Prenatal Diagnosis Center, West China Second University Hospital, Sichuan University, Chengdu, China
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
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Srivastava S, Sahin M, Buxbaum JD, Berry-Kravis E, Soorya LV, Thurm A, Bernstein JA, Asante-Otoo A, Bennett WE, Betancur C, Brickhouse TH, Passos Bueno MR, Chopra M, Christensen CK, Cully JL, Dies K, Friedman K, Gummere B, Holder JL, Jimenez-Gomez A, Kerins CA, Khan O, Kohlenberg T, Lacro RV, Levy LA, Levy T, Linnehan D, Loth E, Moshiree B, Neumeyer A, Paul SM, Phelan K, Persico A, Rapaport R, Rogers C, Saland J, Sethuram S, Shapiro J, Tarr PI, White KM, Wickstrom J, Williams KM, Winrow D, Wishart B, Kolevzon A. Updated consensus guidelines on the management of Phelan-McDermid syndrome. Am J Med Genet A 2023; 191:2015-2044. [PMID: 37392087 PMCID: PMC10524678 DOI: 10.1002/ajmg.a.63312] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/04/2023] [Accepted: 05/18/2023] [Indexed: 07/02/2023]
Abstract
Phelan-McDermid syndrome (PMS) is a genetic condition caused by SHANK3 haploinsufficiency and characterized by a wide range of neurodevelopmental and systemic manifestations. The first practice parameters for assessment and monitoring in individuals with PMS were published in 2014; recently, knowledge about PMS has grown significantly based on data from longitudinal phenotyping studies and large-scale genotype-phenotype investigations. The objective of these updated clinical management guidelines was to: (1) reflect the latest in knowledge in PMS and (2) provide guidance for clinicians, researchers, and the general community. A taskforce was established with clinical experts in PMS and representatives from the parent community. Experts joined subgroups based on their areas of specialty, including genetics, neurology, neurodevelopment, gastroenterology, primary care, physiatry, nephrology, endocrinology, cardiology, gynecology, and dentistry. Taskforce members convened regularly between 2021 and 2022 and produced specialty-specific guidelines based on iterative feedback and discussion. Taskforce leaders then established consensus within their respective specialty group and harmonized the guidelines. The knowledge gained over the past decade allows for improved guidelines to assess and monitor individuals with PMS. Since there is limited evidence specific to PMS, intervention mostly follows general guidelines for treating individuals with developmental disorders. Significant evidence has been amassed to guide the management of comorbid neuropsychiatric conditions in PMS, albeit mainly from caregiver report and the experience of clinical experts. These updated consensus guidelines on the management of PMS represent an advance for the field and will improve care in the community. Several areas for future research are also highlighted and will contribute to subsequent updates with more refined and specific recommendations as new knowledge accumulates.
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Affiliation(s)
- Siddharth Srivastava
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Joseph D. Buxbaum
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Elizabeth Berry-Kravis
- Department of Pediatrics, Rush University Medical Center, Chicago, IL, USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
- Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | | | - Audrey Thurm
- Neurodevelopmental and Behavioral Phenotyping Service, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | | | - Afua Asante-Otoo
- Rehabilitation Medicine Department, NIH Clinical Center, Bethesda, MD, USA
| | - William E. Bennett
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Catalina Betancur
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine, Institut de Biologie Paris Seine, Paris, France
| | - Tegwyn H. Brickhouse
- Department of Dental Public Health & Policy, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Maria Rita Passos Bueno
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Maya Chopra
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Celanie K. Christensen
- Division of Developmental Medicine, Department of Pediatrics, Riley Children’s Health, Indianapolis, IN, USA
- Division of Child Neurology, Department of Neurology, Riley Children’s Health, Indianapolis, IN, USA
| | - Jennifer L. Cully
- Department of Pediatrics, College of Medicine and Division of Dentistry and Orthodontics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Kira Dies
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Kate Friedman
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - J. Lloyd Holder
- Department of Pediatrics-Neurology, Baylor College of Medicine, Houston, TX, USA
| | | | - Carolyn A. Kerins
- Department of Pediatric Dentistry, School of Dentistry, Texas A&M University, Dallas, TX, USA
| | - Omar Khan
- National Institute of Neurological Disease and Stroke, Bethesda, MD, USA
| | | | - Ronald V. Lacro
- Department of Cardiology, Boston Children’s Hospital, Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | | | - Tess Levy
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Eva Loth
- Kings College London, London, UK
| | - Baharak Moshiree
- Department of Medicine, Wake Forest/Atrium Health, Charlotte, NC, USA
| | - Ann Neumeyer
- Lurie Center for Autism, Massachusetts General Hospital, Lexington MA, USA, Harvard Medical School, Boston, MA USA
| | - Scott M. Paul
- Rehabilitation Medicine Department, NIH Clinical Center, Bethesda, MD, USA
| | - Katy Phelan
- Genetics Laboratory, Florida Cancer Specialists and Research Institute, Fort Myers, FL, USA
| | - Antonio Persico
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Robert Rapaport
- Department of Pediatrics, Kravis Children’s Hospital, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Jeffrey Saland
- Department of Pediatrics, Kravis Children’s Hospital, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Swathi Sethuram
- Department of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | | | - Phillip I. Tarr
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Kerry M. White
- Division of Developmental Medicine, Department of Pediatrics, Riley Children’s Health, Indianapolis, IN, USA
- Department of Medical and Molecular Genetics, Riley Children’s Health, Indianapolis, IN, USA
| | - Jordan Wickstrom
- Sinai Rehabilitation Center, Lifebridge Health, Baltimore, MD, USA
| | - Kent M. Williams
- Department of Pediatrics, The Ohio State University School of Medicine, Columbus, OH, USA
| | | | | | - Alexander Kolevzon
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pediatrics, Kravis Children’s Hospital, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Sönmez HE, Savaş M, Aliyeva B, Deniz A, Güngör M, Anık Y, Kara B. The Effect of Interleukin-1 Antagonists on Brain Volume and Cognitive Function in Two Patients With Megalencephalic Leukoencephalopathy With Subcortical Cysts. Pediatr Neurol 2023; 144:72-77. [PMID: 37172460 DOI: 10.1016/j.pediatrneurol.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/27/2023] [Accepted: 04/11/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly and progressive white matter vacuolation. The MLC1 protein plays a role in astrocyte activation during neuroinflammation and regulates volume decrease following astrocyte osmotic swelling. Loss of MLC1 function activates interleukin (IL)-1β-induced inflammatory signals. Theoretically, IL-1 antagonists (such as anakinra and canakinumab) can slow the progression of MLC. Herein, we present two boys from different families who had MLC due to biallelic MLC1 gene mutations and were treated with the anti-IL-1 drug anakinra. METHODS Two boys from different families presented with megalencephaly and psychomotor retardation. Brain magnetic resonance imaging findings in both patients were compatible with the diagnosis of MLC. The diagnosis of MLC was confirmed via Sanger analysis of the MLC1 gene. Anakinra was administered to both patients. Volumetric brain studies and psychometric evaluations were performed before and after anakinra treatment. RESULTS After anakinra therapy, brain volume in both patients decreased significantly and cognitive functions and social interactions improved. No adverse effects were observed during anakinra therapy. CONCLUSIONS Anakinra or other IL-1 antagonists can be used to suppress disease activity in patients with MLC; however, the present findings need to be confirmed via additional research.
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Affiliation(s)
- Hafize Emine Sönmez
- Kocaeli University Faculty of Medicine, Division of Pediatric Rheumatology, Department of Pediatrics, Kocaeli, Turkey.
| | - Merve Savaş
- Atlas University Faculty of Health Sciences, Department of Speech and Language Therapy, Istanbul, Turkey
| | - Bülbül Aliyeva
- Kocaeli University Faculty of Medicine, Department of Child and Adolescent Psychiatry, Kocaeli, Turkey
| | - Adnan Deniz
- Kocaeli University Faculty of Medicine, Division of Child Neurology, Department of Pediatrics, Kocaeli, Turkey
| | - Mesut Güngör
- Kocaeli University Faculty of Medicine, Division of Child Neurology, Department of Pediatrics, Kocaeli, Turkey
| | - Yonca Anık
- Kocaeli University Faculty of Medicine, Division of Child Neuroradiology, Department of Radiology, Kocaeli, Turkey
| | - Bülent Kara
- Kocaeli University Faculty of Medicine, Division of Child Neurology, Department of Pediatrics, Kocaeli, Turkey
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Brignone MS, Lanciotti A, Michelucci A, Mallozzi C, Camerini S, Catacuzzeno L, Sforna L, Caramia M, D’Adamo MC, Ceccarini M, Molinari P, Macioce P, Macchia G, Petrucci TC, Pessia M, Visentin S, Ambrosini E. The CaMKII/MLC1 Axis Confers Ca2+-Dependence to Volume-Regulated Anion Channels (VRAC) in Astrocytes. Cells 2022; 11:cells11172656. [PMID: 36078064 PMCID: PMC9454758 DOI: 10.3390/cells11172656] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/30/2022] Open
Abstract
Astrocytes, the main glial cells of the central nervous system, play a key role in brain volume control due to their intimate contacts with cerebral blood vessels and the expression of a distinctive equipment of proteins involved in solute/water transport. Among these is MLC1, a protein highly expressed in perivascular astrocytes and whose mutations cause megalencephalic leukoencephalopathy with subcortical cysts (MLC), an incurable leukodystrophy characterized by macrocephaly, chronic brain edema, cysts, myelin vacuolation, and astrocyte swelling. Although, in astrocytes, MLC1 mutations are known to affect the swelling-activated chloride currents (ICl,swell) mediated by the volume-regulated anion channel (VRAC), and the regulatory volume decrease, MLC1′s proper function is still unknown. By combining molecular, biochemical, proteomic, electrophysiological, and imaging techniques, we here show that MLC1 is a Ca2+/Calmodulin-dependent protein kinase II (CaMKII) target protein, whose phosphorylation, occurring in response to intracellular Ca2+ release, potentiates VRAC-mediated ICl,swell. Overall, these findings reveal that MLC1 is a Ca2+-regulated protein, linking volume regulation to Ca2+ signaling in astrocytes. This knowledge provides new insight into the MLC1 protein function and into the mechanisms controlling ion/water exchanges in the brain, which may help identify possible molecular targets for the treatment of MLC and other pathological conditions caused by astrocyte swelling and brain edema.
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Affiliation(s)
| | - Angela Lanciotti
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Antonio Michelucci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Cinzia Mallozzi
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Serena Camerini
- Core Facilities (FAST), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Luigi Sforna
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Martino Caramia
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Maria Cristina D’Adamo
- Department of Medicine and Surgery, LUM Giuseppe Degennaro University, 70010 Bari, Italy
| | - Marina Ceccarini
- National Centre for Rare Diseases, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Paola Molinari
- National Centre for Drug Research and Evaluation (FARVA), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Pompeo Macioce
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | | | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD2080 Msida, Malta
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Sergio Visentin
- National Centre for Drug Research and Evaluation (FARVA), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Elena Ambrosini
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
- Correspondence: ; Tel.: +39-06-4990-2037
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Nowacki JC, Fields AM, Fu MM. Emerging cellular themes in leukodystrophies. Front Cell Dev Biol 2022; 10:902261. [PMID: 36003149 PMCID: PMC9393611 DOI: 10.3389/fcell.2022.902261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Leukodystrophies are a broad spectrum of neurological disorders that are characterized primarily by deficiencies in myelin formation. Clinical manifestations of leukodystrophies usually appear during childhood and common symptoms include lack of motor coordination, difficulty with or loss of ambulation, issues with vision and/or hearing, cognitive decline, regression in speech skills, and even seizures. Many cases of leukodystrophy can be attributed to genetic mutations, but they have diverse inheritance patterns (e.g., autosomal recessive, autosomal dominant, or X-linked) and some arise from de novo mutations. In this review, we provide an updated overview of 35 types of leukodystrophies and focus on cellular mechanisms that may underlie these disorders. We find common themes in specialized functions in oligodendrocytes, which are specialized producers of membranes and myelin lipids. These mechanisms include myelin protein defects, lipid processing and peroxisome dysfunction, transcriptional and translational dysregulation, disruptions in cytoskeletal organization, and cell junction defects. In addition, non-cell-autonomous factors in astrocytes and microglia, such as autoimmune reactivity, and intercellular communication, may also play a role in leukodystrophy onset. We hope that highlighting these themes in cellular dysfunction in leukodystrophies may yield conceptual insights on future therapeutic approaches.
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GPR37 Receptors and Megalencephalic Leukoencephalopathy with Subcortical Cysts. Int J Mol Sci 2022; 23:ijms23105528. [PMID: 35628339 PMCID: PMC9144339 DOI: 10.3390/ijms23105528] [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: 04/21/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 11/30/2022] Open
Abstract
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare type of vacuolating leukodystrophy (white matter disorder), which is mainly caused by defects in MLC1 or glial cell adhesion molecule (GlialCAM) proteins. In addition, autoantibodies to GlialCAM are involved in the pathology of multiple sclerosis. MLC1 and GLIALCAM genes encode for membrane proteins of unknown function, which has been linked to the regulation of different ion channels and transporters, such as the chloride channel VRAC (volume regulated anion channel), ClC-2 (chloride channel 2), and connexin 43 or the Na+/K+-ATPase pump. However, the mechanisms by which MLC proteins regulate these ion channels and transporters, as well as the exact function of MLC proteins remain obscure. It has been suggested that MLC proteins might regulate signalling pathways, but the mechanisms involved are, at present, unknown. With the aim of answering these questions, we have recently described the brain GlialCAM interactome. Within the identified proteins, we could validate the interaction with several G protein-coupled receptors (GPCRs), including the orphan GPRC5B and the proposed prosaposin receptors GPR37L1 and GPR37. In this review, we summarize new aspects of the pathophysiology of MLC disease and key aspects of the interaction between GPR37 receptors and MLC proteins.
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Sadek AA, Aladawy MA, Mansour TMM, Ibrahim MF, Mohamed MM, Gad EF, Othman AA, Ahmed HA, Kasim AK, Wagdy WM, Hasan MHT, Abdelkreem E. Clinicoradiologic Correlation in 22 Egyptian Children With Megalencephalic Leukoencephalopathy With Subcortical Cysts. J Child Neurol 2022; 37:380-389. [PMID: 35322718 DOI: 10.1177/08830738221078683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare genetic form of cerebral white matter disease whose clinicoradiologic correlation has not been completely understood. In this study, we investigated the association between clinical and brain magnetic resonance imaging (MRI) features in 22 Egyptian children (median age 7 years) with MLC. Gross motor function was assessed using the Gross Motor Function Classification System, and evaluation of brain MRI followed a consistent scoring system. Each parameter of extensive cerebral white matter T2 hyperintensity, moderate-to-severe wide ventricle/enlarged subarachnoid space, and greater than 2 temporal subcortical cysts was significantly associated (P < .05) with worse Gross Motor Function Classification System score, language abnormality, and ataxia. Having >2 parietal subcortical cysts was significantly related to a worse Gross Motor Function Classification System score (P = .04). The current study indicates that patients with MLC manifest signification association between certain brain MRI abnormalities and neurologic features, but this should be confirmed in larger studies.
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Affiliation(s)
- Abdelrahim A Sadek
- Neuropsychiatry Unit, Department of Pediatrics, 68890Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Mohammed A Aladawy
- Neurology Unit, Department of Pediatrics, Faculty of Medicine, 195495Al-Azhar University, Assiut, Egypt
| | - Tarek M M Mansour
- Department of Radio-diagnosis, Faculty of Medicine, 68820Al-Azhar University, Assiut, Egypt
| | - Mohamed F Ibrahim
- Neurology Unit, Department of Pediatrics, Faculty of Medicine, 195495Al-Azhar University, Assiut, Egypt
| | - Montaser M Mohamed
- Department of Pediatrics, 68890Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Eman F Gad
- Department of Pediatrics, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Amr A Othman
- Neuropsychiatry Unit, Department of Pediatrics, 68890Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Hosny A Ahmed
- Neurology Unit, Department of Pediatrics, Faculty of Medicine, 195495Al-Azhar University, Assiut, Egypt
| | - Abdin K Kasim
- Department of Neurosurgery, 68890Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Wael M Wagdy
- Department of Radio-diagnosis, 113328Faculty of Medicine, South Valley University, Qena, Egypt
| | - Mohamed H T Hasan
- Department of Radio-diagnosis, Faculty of Medicine, 68820Al-Azhar University, Cairo, Egypt
| | - Elsayed Abdelkreem
- Department of Pediatrics, 68890Faculty of Medicine, Sohag University, Sohag, Egypt
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Lo J, Forst AL, Warth R, Zdebik AA. EAST/SeSAME Syndrome and Beyond: The Spectrum of Kir4.1- and Kir5.1-Associated Channelopathies. Front Physiol 2022; 13:852674. [PMID: 35370765 PMCID: PMC8965613 DOI: 10.3389/fphys.2022.852674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 12/13/2022] Open
Abstract
In 2009, two groups independently linked human mutations in the inwardly rectifying K+ channel Kir4.1 (gene name KCNJ10) to a syndrome affecting the central nervous system (CNS), hearing, and renal tubular salt reabsorption. The autosomal recessive syndrome has been named EAST (epilepsy, ataxia, sensorineural deafness, and renal tubulopathy) or SeSAME syndrome (seizures, sensorineural deafness, ataxia, intellectual disability, and electrolyte imbalance), accordingly. Renal dysfunction in EAST/SeSAME patients results in loss of Na+, K+, and Mg2+ with urine, activation of the renin-angiotensin-aldosterone system, and hypokalemic metabolic alkalosis. Kir4.1 is highly expressed in affected organs: the CNS, inner ear, and kidney. In the kidney, it mostly forms heteromeric channels with Kir5.1 (KCNJ16). Biallelic loss-of-function mutations of Kir5.1 can also have disease significance, but the clinical symptoms differ substantially from those of EAST/SeSAME syndrome: although sensorineural hearing loss and hypokalemia are replicated, there is no alkalosis, but rather acidosis of variable severity; in contrast to EAST/SeSAME syndrome, the CNS is unaffected. This review provides a framework for understanding some of these differences and will guide the reader through the growing literature on Kir4.1 and Kir5.1, discussing the complex disease mechanisms and the variable expression of disease symptoms from a molecular and systems physiology perspective. Knowledge of the pathophysiology of these diseases and their multifaceted clinical spectrum is an important prerequisite for making the correct diagnosis and forms the basis for personalized therapies.
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Affiliation(s)
- Jacky Lo
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Anna-Lena Forst
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Richard Warth
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Anselm A. Zdebik
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Centre for Nephrology, University College London, London, United Kingdom
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10
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Pogodalla N, Winkler B, Klämbt C. Glial Tiling in the Insect Nervous System. Front Cell Neurosci 2022; 16:825695. [PMID: 35250488 PMCID: PMC8891220 DOI: 10.3389/fncel.2022.825695] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/06/2022] [Indexed: 11/30/2022] Open
Abstract
The Drosophila nervous system comprises a small number of well characterized glial cell classes. The outer surface of the central nervous system (CNS) is protected by a glial derived blood-brain barrier generated by perineurial and subperineurial glia. All neural stem cells and all neurons are engulfed by cortex glial cells. The inner neuropil region, that harbors all synapses and dendrites, is covered by ensheathing glia and infiltrated by astrocyte-like glial cells. All these glial cells show a tiled organization with an often remarkable plasticity where glial cells of one cell type invade the territory of the neighboring glial cell type upon its ablation. Here, we summarize the different glial tiling patterns and based on the different modes of cell-cell contacts we hypothesize that different molecular mechanisms underlie tiling of the different glial cell types.
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Lanciotti A, Brignone MS, Macioce P, Visentin S, Ambrosini E. Human iPSC-Derived Astrocytes: A Powerful Tool to Study Primary Astrocyte Dysfunction in the Pathogenesis of Rare Leukodystrophies. Int J Mol Sci 2021; 23:ijms23010274. [PMID: 35008700 PMCID: PMC8745131 DOI: 10.3390/ijms23010274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are very versatile cells, endowed with multitasking capacities to ensure brain homeostasis maintenance from brain development to adult life. It has become increasingly evident that astrocytes play a central role in many central nervous system pathologies, not only as regulators of defensive responses against brain insults but also as primary culprits of the disease onset and progression. This is particularly evident in some rare leukodystrophies (LDs) where white matter/myelin deterioration is due to primary astrocyte dysfunctions. Understanding the molecular defects causing these LDs may help clarify astrocyte contribution to myelin formation/maintenance and favor the identification of possible therapeutic targets for LDs and other CNS demyelinating diseases. To date, the pathogenic mechanisms of these LDs are poorly known due to the rarity of the pathological tissue and the failure of the animal models to fully recapitulate the human diseases. Thus, the development of human induced pluripotent stem cells (hiPSC) from patient fibroblasts and their differentiation into astrocytes is a promising approach to overcome these issues. In this review, we discuss the primary role of astrocytes in LD pathogenesis, the experimental models currently available and the advantages, future evolutions, perspectives, and limitations of hiPSC to study pathologies implying astrocyte dysfunctions.
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Affiliation(s)
- Angela Lanciotti
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
| | - Maria Stefania Brignone
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
| | - Pompeo Macioce
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
| | - Sergio Visentin
- National Center for Research and Preclinical and Clinical Evaluation of Drugs, Istituto Superiore di Sanità, 00169 Rome, Italy;
| | - Elena Ambrosini
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
- Correspondence: ; Tel.: +39-064-990-2037
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Hwang J, Park K, Lee GY, Yoon BY, Kim H, Roh SH, Lee BC, Kim K, Lim HH. Transmembrane topology and oligomeric nature of an astrocytic membrane protein, MLC1. Open Biol 2021; 11:210103. [PMID: 34847774 PMCID: PMC8633789 DOI: 10.1098/rsob.210103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
MLC1 is a membrane protein mainly expressed in astrocytes, and genetic mutations lead to the development of a leukodystrophy, megalencephalic leukoencephalopathy with subcortical cysts disease. Currently, the biochemical properties of the MLC1 protein are largely unknown. In this study, we aimed to characterize the transmembrane (TM) topology and oligomeric nature of the MLC1 protein. Systematic immunofluorescence staining data revealed that the MLC1 protein has eight TM domains and that both the N- and C-terminus face the cytoplasm. We found that MLC1 can be purified as an oligomer and could form a trimeric complex in both detergent micelles and reconstituted proteoliposomes. Additionally, a single-molecule photobleaching experiment showed that MLC1 protein complexes could consist of three MLC1 monomers in the reconstituted proteoliposomes. These results can provide a basis for both the high-resolution structural determination and functional characterization of the MLC1 protein.
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Affiliation(s)
- Junmo Hwang
- Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 61 Cheomdan-ro, Dong-gu, Daegu 41068, Republic of Korea
| | - Kunwoong Park
- Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 61 Cheomdan-ro, Dong-gu, Daegu 41068, Republic of Korea
| | - Ga-Young Lee
- Brain Research Core Facility, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea
| | - Bo Young Yoon
- Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 61 Cheomdan-ro, Dong-gu, Daegu 41068, Republic of Korea
| | - Hyunmin Kim
- School of Biological Science, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Republic of Korea
| | - Sung Hoon Roh
- School of Biological Science, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Republic of Korea
| | - Byoung-Cheol Lee
- Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 61 Cheomdan-ro, Dong-gu, Daegu 41068, Republic of Korea
| | - Kipom Kim
- Brain Research Core Facility, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea
| | - Hyun-Ho Lim
- Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 61 Cheomdan-ro, Dong-gu, Daegu 41068, Republic of Korea,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
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Alonso-Gardón M, Elorza-Vidal X, Castellanos A, La Sala G, Armand-Ugon M, Gilbert A, Di Pietro C, Pla-Casillanis A, Ciruela F, Gasull X, Nunes V, Martínez A, Schulte U, Cohen-Salmon M, Marazziti D, Estévez R. Identification of the GlialCAM interactome: the G protein-coupled receptors GPRC5B and GPR37L1 modulate megalencephalic leukoencephalopathy proteins. Hum Mol Genet 2021; 30:1649-1665. [PMID: 34100078 PMCID: PMC8369841 DOI: 10.1093/hmg/ddab155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 12/23/2022] Open
Abstract
Megalencephalic Leukoencephalopathy with subcortical Cysts (MLC) is a type of vacuolating leukodystrophy, which is mainly caused by mutations in MLC1 or GLIALCAM. The two MLC-causing genes encode for membrane proteins of yet unknown function that have been linked to the regulation of different chloride channels such as the ClC-2 and VRAC. To gain insight into the role of MLC proteins, we have determined the brain GlialCAM interacting proteome. The proteome includes different transporters and ion channels known to be involved in the regulation of brain homeostasis, proteins related to adhesion or signaling as several G protein-coupled receptors (GPCRs), including the orphan GPRC5B and the proposed prosaposin receptor GPR37L1. Focusing on these two GPCRs, we could validate that they interact directly with MLC proteins. The inactivation of Gpr37l1 in mice upregulated MLC proteins without altering their localization. Conversely, a reduction of GPRC5B levels in primary astrocytes downregulated MLC proteins, leading to an impaired activation of ClC-2 and VRAC. The interaction between the GPCRs and MLC1 was dynamically regulated upon changes in the osmolarity or potassium concentration. We propose that GlialCAM and MLC1 associate with different integral membrane proteins modulating their functions and acting as a recruitment site for various signaling components as the GPCRs identified here. We hypothesized that the GlialCAM/MLC1 complex is working as an adhesion molecule coupled to a tetraspanin-like molecule performing regulatory effects through direct binding or influencing signal transduction events.
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Affiliation(s)
- Marta Alonso-Gardón
- Departament de Ciències Fisiològiques, Genes Disease and Therapy Program IDIBELL - Institute of Neurosciences, Universitat de Barcelona, Barcelona 08036, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Xabier Elorza-Vidal
- Departament de Ciències Fisiològiques, Genes Disease and Therapy Program IDIBELL - Institute of Neurosciences, Universitat de Barcelona, Barcelona 08036, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Aida Castellanos
- Departament de Ciències Fisiològiques, Genes Disease and Therapy Program IDIBELL - Institute of Neurosciences, Universitat de Barcelona, Barcelona 08036, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Gina La Sala
- Institute of Biochemistry and Cell Biology, Italian National Research Council (CNR), Monterotondo Scalo, Rome I-00015, Italy
| | - Mercedes Armand-Ugon
- Departament de Ciències Fisiològiques, Genes Disease and Therapy Program IDIBELL - Institute of Neurosciences, Universitat de Barcelona, Barcelona 08036, Spain
| | - Alice Gilbert
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris F-75005, France
| | - Chiara Di Pietro
- Institute of Biochemistry and Cell Biology, Italian National Research Council (CNR), Monterotondo Scalo, Rome I-00015, Italy
| | - Adrià Pla-Casillanis
- Departament de Ciències Fisiològiques, Genes Disease and Therapy Program IDIBELL - Institute of Neurosciences, Universitat de Barcelona, Barcelona 08036, Spain
| | - Francisco Ciruela
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona-IDIBELL, L'Hospitalet de Llobregat, Barcelona 08036, Spain
| | - Xavier Gasull
- Neurophysiology Laboratory, Department of Biomedicine, Medical School, Institute of Neurosciences, University of Barcelona-IDIBAPS, Casanova 143 Barcelona 08036, Spain
| | - Virginia Nunes
- Unitat de Genètica, Departament de Ciències Fisiològiques, Universitat de Barcelona, Laboratori de Genètica Molecular, Genes Disease and Therapy Program IDIBELL, L'Hospitalet de Llobregat 08036, Spain
| | - Albert Martínez
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain
| | | | - Martine Cohen-Salmon
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris F-75005, France
| | - Daniela Marazziti
- Institute of Biochemistry and Cell Biology, Italian National Research Council (CNR), Monterotondo Scalo, Rome I-00015, Italy
| | - Raúl Estévez
- Departament de Ciències Fisiològiques, Genes Disease and Therapy Program IDIBELL - Institute of Neurosciences, Universitat de Barcelona, Barcelona 08036, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid 28029, Spain
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Kumar A, Sakakura K, Mitsuhashi T, Railean A, Luat AF. Alteration of the Arcuate Fasciculus in Jacobsen Syndrome Shown by Diffusion Tensor Imaging. Pediatr Neurol 2021; 120:4-6. [PMID: 33962347 DOI: 10.1016/j.pediatrneurol.2021.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 11/18/2022]
Affiliation(s)
- Ananyaa Kumar
- Division of Pediatric Neurology, Children's Hospital of Michigan, Detroit, Michigan
| | - Kazuki Sakakura
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan; Department of Neurosurgery, University of Tsukuba, Tsukuba, Japan
| | - Takumi Mitsuhashi
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan; Department of Neurosurgery, Juntendo University, Tokyo, Japan
| | - Anastasia Railean
- Department of Pediatrics, Wake Forest Baptist Health and Brenner Children's Hospital, Winston-Salem, North Carolina
| | - Aimee F Luat
- Division of Pediatric Neurology, Children's Hospital of Michigan, Detroit, Michigan; Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan; Carman and Ann Adams, Department of Pediatrics, Children's Hospital of Michigan, Detroit, Michigan; Department of Pediatrics Central Michigan University College of Medicine, Mt. Pleasant, Michigan.
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