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Brocato ER, Easter R, Morgan A, Kakani M, Lee G, Wolstenholme JT. Adolescent binge ethanol impacts H3K9me3-occupancy at synaptic genes and the regulation of oligodendrocyte development. Front Mol Neurosci 2024; 17:1389100. [PMID: 38840776 PMCID: PMC11150558 DOI: 10.3389/fnmol.2024.1389100] [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: 02/20/2024] [Accepted: 05/06/2024] [Indexed: 06/07/2024] Open
Abstract
Introduction Binge drinking in adolescence can disrupt myelination and cause brain structural changes that persist into adulthood. Alcohol consumption at a younger age increases the susceptibility of these changes. Animal models to understand ethanol's actions on myelin and white matter show that adolescent binge ethanol can alter the developmental trajectory of oligodendrocytes, myelin structure, and myelin fiber density. Oligodendrocyte differentiation is epigenetically regulated by H3K9 trimethylation (H3K9me3). Prior studies have shown that adolescent binge ethanol dysregulates H3K9 methylation and decreases H3K9-related gene expression in the PFC. Methods Here, we assessed ethanol-induced changes to H3K9me3 occupancy at genomic loci in the developing adolescent PFC. We further assessed ethanol-induced changes at the transcription level with qPCR time course approaches in oligodendrocyte-enriched cells to assess changes in oligodendrocyte progenitor and oligodendrocytes specifically. Results Adolescent binge ethanol altered H3K9me3 regulation of synaptic-related genes and genes specific for glutamate and potassium channels in a sex-specific manner. In PFC tissue, we found an early change in gene expression in transcription factors associated with oligodendrocyte differentiation that may lead to the later significant decrease in myelin-related gene expression. This effect appeared stronger in males. Conclusion Further exploration in oligodendrocyte cell enrichment time course and dose response studies could suggest lasting dysregulation of oligodendrocyte maturation at the transcriptional level. Overall, these studies suggest that binge ethanol may impede oligodendrocyte differentiation required for ongoing myelin development in the PFC by altering H3K9me3 occupancy at synaptic-related genes. We identify potential genes that may be contributing to adolescent binge ethanol-related myelin loss.
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Affiliation(s)
- Emily R. Brocato
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
| | - Rachel Easter
- Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Alanna Morgan
- Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Meenakshi Kakani
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
| | - Grace Lee
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
| | - Jennifer T. Wolstenholme
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
- Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
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2
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Zito A, Lee JT. Variable expression of MECP2, CDKL5, and FMR1 in the human brain: Implications for gene restorative therapies. Proc Natl Acad Sci U S A 2024; 121:e2312757121. [PMID: 38386709 PMCID: PMC10907246 DOI: 10.1073/pnas.2312757121] [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: 07/25/2023] [Accepted: 12/28/2023] [Indexed: 02/24/2024] Open
Abstract
MECP2, CDKL5, and FMR1 are three X-linked neurodevelopmental genes associated with Rett, CDKL5-, and fragile-X syndrome, respectively. These syndromes are characterized by distinct constellations of severe cognitive and neurobehavioral anomalies, reflecting the broad but unique expression patterns of each of the genes in the brain. As these disorders are not thought to be neurodegenerative and may be reversible, a major goal has been to restore expression of the functional proteins in the patient's brain. Strategies have included gene therapy, gene editing, and selective Xi-reactivation methodologies. However, tissue penetration and overall delivery to various regions of the brain remain challenging for each strategy. Thus, gaining insights into how much restoration would be required and what regions/cell types in the brain must be targeted for meaningful physiological improvement would be valuable. As a step toward addressing these questions, here we perform a meta-analysis of single-cell transcriptomics data from the human brain across multiple developmental stages, in various brain regions, and in multiple donors. We observe a substantial degree of expression variability for MECP2, CDKL5, and FMR1 not only across cell types but also between donors. The wide range of expression may help define a therapeutic window, with the low end delineating a minimum level required to restore physiological function and the high end informing toxicology margin. Finally, the inter-cellular and inter-individual variability enable identification of co-varying genes and will facilitate future identification of biomarkers.
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Affiliation(s)
- Antonino Zito
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA02114
- Department of Genetics, The Blavatnik Institute, Harvard Medical School, Boston, MA02114
| | - Jeannie T. Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA02114
- Department of Genetics, The Blavatnik Institute, Harvard Medical School, Boston, MA02114
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3
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Mir FA, Amanullah A, Jain BP, Hyderi Z, Gautam A. Neuroepigenetics of ageing and neurodegeneration-associated dementia: An updated review. Ageing Res Rev 2023; 91:102067. [PMID: 37689143 DOI: 10.1016/j.arr.2023.102067] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023]
Abstract
Gene expression is tremendously altered in the brain during memory acquisition, recall, and forgetfulness. However, non-genetic factors, including environmental elements, epigenetic changes, and lifestyle, have grabbed significant attention in recent years regarding the etiology of neurodegenerative diseases (NDD) and age-associated dementia. Epigenetic modifications are essential in regulating gene expression in all living organisms in a DNA sequence-independent manner. The genes implicated in ageing and NDD-related memory disorders are epigenetically regulated by processes such as DNA methylation, histone acetylation as well as messenger RNA editing machinery. The physiological and optimal state of the epigenome, especially within the CNS of humans, plays an intricate role in helping us adjust to the changing environment, and alterations in it cause many brain disorders, but the mechanisms behind it still need to be well understood. When fully understood, these epigenetic landscapes could act as vital targets for pharmacogenetic rescue strategies for treating several diseases, including neurodegeneration- and age-induced dementia. Keeping this objective in mind, this updated review summarises the epigenetic changes associated with age and neurodegeneration-associated dementia.
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Affiliation(s)
- Fayaz Ahmad Mir
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - Zeeshan Hyderi
- Department of Biotechnology, Alagappa University, Karaikudi, India
| | - Akash Gautam
- Centre for Neural and Cognitive Sciences, University of Hyderabad, Hyderabad, India.
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4
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Krämer-Albers EM, Werner HB. Mechanisms of axonal support by oligodendrocyte-derived extracellular vesicles. Nat Rev Neurosci 2023:10.1038/s41583-023-00711-y. [PMID: 37258632 DOI: 10.1038/s41583-023-00711-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/02/2023]
Abstract
Extracellular vesicles (EVs) have recently emerged as versatile elements of cell communication in the nervous system, mediating tissue homeostasis. EVs influence the physiology of their target cells via horizontal transfer of molecular cargo between cells and by triggering signalling pathways. In this Review, we discuss recent work revealing that EVs mediate interactions between oligodendrocytes and neurons, which are relevant for maintaining the structural integrity of axons. In response to neuronal activity, myelinating oligodendrocytes release EVs, which are internalized by neurons and provide axons with key factors that improve axonal transport, stress resistance and energy homeostasis. Glia-to-neuron transfer of EVs is thus a crucial facet of axonal preservation. When glial support is impaired, axonal integrity is progressively lost, as observed in myelin-related disorders, other neurodegenerative diseases and with normal ageing. We highlight the mechanisms that oligodendroglial EVs use to sustain axonal integrity and function.
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Affiliation(s)
- Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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5
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Palmieri M, Pozzer D, Landsberger N. Advanced genetic therapies for the treatment of Rett syndrome: state of the art and future perspectives. Front Neurosci 2023; 17:1172805. [PMID: 37304036 PMCID: PMC10248472 DOI: 10.3389/fnins.2023.1172805] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Loss and gain of functions mutations in the X-linked MECP2 (methyl-CpG-binding protein 2) gene are responsible for a set of generally severe neurological disorders that can affect both genders. In particular, Mecp2 deficiency is mainly associated with Rett syndrome (RTT) in girls, while duplication of the MECP2 gene leads, mainly in boys, to the MECP2 duplication syndrome (MDS). No cure is currently available for MECP2 related disorders. However, several studies have reported that by re-expressing the wild-type gene is possible to restore defective phenotypes of Mecp2 null animals. This proof of principle endorsed many laboratories to search for novel therapeutic strategies to cure RTT. Besides pharmacological approaches aimed at modulating MeCP2-downstream pathways, genetic targeting of MECP2 or its transcript have been largely proposed. Remarkably, two studies focused on augmentative gene therapy were recently approved for clinical trials. Both use molecular strategies to well-control gene dosage. Notably, the recent development of genome editing technologies has opened an alternative way to specifically target MECP2 without altering its physiological levels. Other attractive approaches exclusively applicable for nonsense mutations are the translational read-through (TR) and t-RNA suppressor therapy. Reactivation of the MECP2 locus on the silent X chromosome represents another valid choice for the disease. In this article, we intend to review the most recent genetic interventions for the treatment of RTT, describing the current state of the art, and the related advantages and concerns. We will also discuss the possible application of other advanced therapies, based on molecular delivery through nanoparticles, already proposed for other neurological disorders but still not tested in RTT.
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Affiliation(s)
- Michela Palmieri
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
| | - Diego Pozzer
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
| | - Nicoletta Landsberger
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Faculty of Medicine and Surgery, University of Milan, Milan, Italy
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6
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Singh J, Goodman-Vincent E, Santosh P. Evidence Synthesis of Gene Therapy and Gene Editing from Different Disorders-Implications for Individuals with Rett Syndrome: A Systematic Review. Int J Mol Sci 2023; 24:ijms24109023. [PMID: 37240368 DOI: 10.3390/ijms24109023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/06/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
This systematic review and thematic analysis critically evaluated gene therapy trials in amyotrophic lateral sclerosis, haemoglobinopathies, immunodeficiencies, leukodystrophies, lysosomal storage disorders and retinal dystrophies and extrapolated the key clinical findings to individuals with Rett syndrome (RTT). The PRISMA guidelines were used to search six databases during the last decade, followed by a thematic analysis to identify the emerging themes. Thematic analysis across the different disorders revealed four themes: (I) Therapeutic time window of gene therapy; (II) Administration and dosing strategies for gene therapy; (III) Methods of gene therapeutics and (IV) Future areas of clinical interest. Our synthesis of information has further enriched the current clinical evidence base and can assist in optimising gene therapy and gene editing studies in individuals with RTT, but it would also benefit when applied to other disorders. The findings suggest that gene therapies have better outcomes when the brain is not the primary target. Across different disorders, early intervention appears to be more critical, and targeting the pre-symptomatic stage might prevent symptom pathology. Intervention at later stages of disease progression may benefit by helping to clinically stabilise patients and preventing disease-related symptoms from worsening. If gene therapy or editing has the desired outcome, older patients would need concerted rehabilitation efforts to reverse their impairments. The timing of intervention and the administration route would be critical parameters for successful outcomes of gene therapy/editing trials in individuals with RTT. Current approaches also need to overcome the challenges of MeCP2 dosing, genotoxicity, transduction efficiencies and biodistribution.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
| | - Ella Goodman-Vincent
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
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7
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Sun J, Osenberg S, Irwin A, Ma LH, Lee N, Xiang Y, Li F, Wan YW, Park IH, Maletic-Savatic M, Ballas N. Mutations in the transcriptional regulator MeCP2 severely impact key cellular and molecular signatures of human astrocytes during maturation. Cell Rep 2023; 42:111942. [PMID: 36640327 PMCID: PMC10857774 DOI: 10.1016/j.celrep.2022.111942] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 06/12/2022] [Accepted: 12/16/2022] [Indexed: 01/06/2023] Open
Abstract
Mutations in the MECP2 gene underlie a spectrum of neurodevelopmental disorders, most commonly Rett syndrome (RTT). We ask whether MECP2 mutations interfere with human astrocyte developmental maturation, thereby affecting their ability to support neurons. Using human-based models, we show that RTT-causing MECP2 mutations greatly impact the key role of astrocytes in regulating overall brain bioenergetics and that these metabolic aberrations are likely mediated by dysfunctional mitochondria. During post-natal maturation, astrocytes rely on neurons to induce their complex stellate morphology and transcriptional changes. While MECP2 mutations cause cell-intrinsic aberrations in the astrocyte transcriptional landscape, surprisingly, they do not affect the neuron-induced astrocyte gene expression. Notably, however, astrocytes are unable to develop complex mature morphology due to cell- and non-cell-autonomous aberrations caused by MECP2 mutations. Thus, MECP2 mutations critically impact key cellular and molecular features of human astrocytes and, hence, their ability to interact and support the structural and functional maturation of neurons.
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Affiliation(s)
- Jialin Sun
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Sivan Osenberg
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA; Departments of Pediatrics-Neurology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Austin Irwin
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Li-Hua Ma
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nigel Lee
- Departments of Pediatrics-Neurology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Yangfei Xiang
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06520, USA
| | - Feng Li
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA; Center for Drug Discovery and Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ying-Wooi Wan
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06520, USA
| | - Mirjana Maletic-Savatic
- Departments of Pediatrics-Neurology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.
| | - Nurit Ballas
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA.
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8
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Petazzi P, Jorge-Torres OC, Gomez A, Scognamiglio I, Serra-Musach J, Merkel A, Grases D, Xiol C, O’Callaghan M, Armstrong J, Esteller M, Guil S. Global Impairment of Immediate-Early Genes Expression in Rett Syndrome Models and Patients Linked to Myelination Defects. Int J Mol Sci 2023; 24:ijms24021453. [PMID: 36674969 PMCID: PMC9864472 DOI: 10.3390/ijms24021453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 12/14/2022] [Accepted: 12/29/2022] [Indexed: 01/15/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disease caused almost exclusively by mutations to the MeCP2 gene. This disease may be regarded as a synaptopathy, with impairments affecting synaptic plasticity, inhibitory and excitatory transmission and network excitability. The complete understanding of the mechanisms behind how the transcription factor MeCP2 so profoundly affects the mammalian brain are yet to be determined. What is known, is that MeCP2 involvement in activity-dependent expression programs is a critical link between this protein and proper neuronal activity, which allows the correct maturation of connections in the brain. By using RNA-sequencing analysis, we found several immediate-early genes (IEGs, key mediators of activity-dependent responses) directly bound by MeCP2 at the chromatin level and upregulated in the hippocampus and prefrontal cortex of the Mecp2-KO mouse. Quantification of the IEGs response to stimulus both in vivo and in vitro detected an aberrant expression pattern in MeCP2-deficient neurons. Furthermore, altered IEGs levels were found in RTT patient's peripheral blood and brain regions of post-mortem samples, correlating with impaired expression of downstream myelination-related genes. Altogether, these data indicate that proper IEGs expression is crucial for correct synaptic development and that MeCP2 has a key role in the regulation of IEGs.
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Affiliation(s)
- Paolo Petazzi
- Josep Carreras Leukemia Research Institute, School of Medicine, University of Barcelona, Carrer Casanova 143, 400° floor, 08036 Barcelona, Spain
- RICORS-TERAV, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Olga Caridad Jorge-Torres
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, 08916 Barcelona, Spain
- Correspondence: (O.C.J.-T.); (S.G.); Tel.: +34-935572828 (O.C.J.-T. & S.G.)
| | - Antonio Gomez
- Biosciences Department, Faculty of Sciences and Technology (FCT), University of Vic-Central University of Catalonia (UVic-UCC), C. de la Laura, 13, 08500 Vic, Spain
| | - Iolanda Scognamiglio
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Jordi Serra-Musach
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Angelika Merkel
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, 08916 Barcelona, Spain
| | - Daniela Grases
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, 08916 Barcelona, Spain
| | - Clara Xiol
- Fundación San Juan de Dios, 08950 Barcelona, Spain
- Servei de Medicina Genètica i Molecular, Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Mar O’Callaghan
- Clínica Rett, Neurology Department, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Judith Armstrong
- Servei de Medicina Genètica i Molecular, Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Manel Esteller
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, 08916 Barcelona, Spain
- Centro de Investigacion Biomedica en Red Cancer (CIBERONC), 28029 Madrid, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
- Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), 08907 Barcelona, Spain
| | - Sonia Guil
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, 08916 Barcelona, Spain
- Germans Trias i Pujol Health Science Research Institute, Badalona, 08916 Barcelona, Spain
- Correspondence: (O.C.J.-T.); (S.G.); Tel.: +34-935572828 (O.C.J.-T. & S.G.)
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9
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Lu S, Chen Y, Wang Z. Advances in the pathogenesis of Rett syndrome using cell models. Animal Model Exp Med 2022; 5:532-541. [PMID: 35785421 PMCID: PMC9773312 DOI: 10.1002/ame2.12236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/05/2022] [Indexed: 12/30/2022] Open
Abstract
Rett syndrome (RTT) is a progressive neurodevelopmental disorder that occurs mainly in girls with a range of typical symptoms of autism spectrum disorders. MeCP2 protein loss-of-function in neural lineage cells is the main cause of RTT pathogenicity. As it is still hard to understand the mechanism of RTT on the basis of only clinical patients or animal models, cell models cultured in vitro play indispensable roles. Here we reviewed the research progress in the pathogenesis of RTT at the cellular level, summarized the preclinical-research-related applications, and prospected potential future development.
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Affiliation(s)
- Sijia Lu
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational MedicineKunming University of Science and TechnologyKunmingChina,Yunnan Key Laboratory of Primate Biomedical ResearchKunmingChina
| | - Yongchang Chen
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational MedicineKunming University of Science and TechnologyKunmingChina,Yunnan Key Laboratory of Primate Biomedical ResearchKunmingChina
| | - Zhengbo Wang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational MedicineKunming University of Science and TechnologyKunmingChina,Yunnan Key Laboratory of Primate Biomedical ResearchKunmingChina
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10
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Dave A, Pillai PP. Docosahexaenoic acid increased MeCP2 mediated mitochondrial respiratory complexes II and III enzyme activities in cortical astrocytes. J Biochem Mol Toxicol 2022; 36:e23002. [PMID: 35174922 DOI: 10.1002/jbt.23002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 12/16/2021] [Accepted: 01/19/2022] [Indexed: 11/08/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the methyl-CpG-binding protein 2 (MeCP2) in the neurons and glial cells of the central nervous system. Currently, therapeutics for RTT is aimed at restoring the loss-of-function by MeCP2 gene therapy, but that approach has multiple challenges. We have already reported impaired mitochondrial bioenergetics in MeCP2 deficient astrocytes. Docosahexaenoic acid (DHA), a polyunsaturated fatty acid, has been shown with health benefits, but its impact on mitochondrial functions in MeCP2 deficient astrocytes has never been paid much attention. The present study aimed to investigate the effects of DHA on mitochondrial respiratory chain regulation in MeCP2 knockdown astrocytes. We determined NADH dehydrogenase (ubiquinone) flavoprotein 2 (Ndufv2-complex-I), Ubiquinol cytochrome c reductase core protein (Uqcrc1-complex-III) genes expression, Ndufv2 protein expression, respiratory electron transport chain complex I, II, III, and IV enzyme activities, intracellular Ca+2 , reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) in DHA pre-incubated MeCP2 knock-down rat primary cortical astrocytes. Our study demonstrates that 100 µM DHA increases MeCP2 gene and protein expression. Increases brain-derived neurotrophic factor (BDNF) and Uqcrc1 gene expression, Ndufv2 protein expression, but has no effect on glial fibrillary acidic protein (GFAP) gene expression. DHA treatment also increases mitochondrial respiratory Complexes II and III activities and reduces intracellular calcium levels. Taken together, the effects of DHA seem independent of MeCP2 deficiency in astrocytes. Hence, further studies are warranted to understand the complicated mechanisms of DHA and for its therapeutic significance in MeCP2-mediated mitochondrial dysfunction and in RTT disease.
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Affiliation(s)
- Arpita Dave
- Department of Zoology, Division of Neurobiology, The Maharaja Sayajirao University of Baroda, Gujarat, India
| | - Prakash P Pillai
- Department of Zoology, Division of Neurobiology, The Maharaja Sayajirao University of Baroda, Gujarat, India
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11
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Wang Y, Zhang Y, Zhang S, Kim B, Hull VL, Xu J, Prabhu P, Gregory M, Martinez-Cerdeno V, Zhan X, Deng W, Guo F. PARP1-mediated PARylation activity is essential for oligodendroglial differentiation and CNS myelination. Cell Rep 2021; 37:109695. [PMID: 34610310 PMCID: PMC9586836 DOI: 10.1016/j.celrep.2021.109695] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 07/21/2021] [Accepted: 08/18/2021] [Indexed: 12/16/2022] Open
Abstract
The function of poly(ADP-ribosyl) polymerase 1 (PARP1) in myelination and remyelination of the central nervous system (CNS) remains enigmatic. Here, we report that PARP1 is an intrinsic driver for oligodendroglial development and myelination. Genetic PARP1 depletion impairs the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes and impedes CNS myelination. Mechanistically, PARP1-mediated PARylation activity is not only necessary but also sufficient for OPC differentiation. At the molecular level, we identify the RNA-binding protein Myef2 as a PARylated target, which controls OPC differentiation through the PARylation-modulated derepression of myelin protein expression. Furthermore, PARP1’s enzymatic activity is necessary for oligodendrocyte and myelin regeneration after demyelination. Together, our findings suggest that PARP1-mediated PARylation activity may be a potential therapeutic target for promoting OPC differentiation and remyelination in neurological disorders characterized by arrested OPC differentiation and remyelination failure such as multiple sclerosis. Wang et al. show that PARP1-mediated PARylation promotes oligodendroglial differentiation and regeneration. They demonstrate that PARP1 PARylates proteins relating to RNA metabolism under physiological conditions and that Myef2 is identified as one of the potential targets that mediates PARP1-regulated myelin gene expression at the posttranscriptional level during oligodendroglial development.
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Affiliation(s)
- Yan Wang
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Yanhong Zhang
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Sheng Zhang
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Bokyung Kim
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Vanessa L Hull
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Jie Xu
- Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Preeti Prabhu
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Maria Gregory
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Veronica Martinez-Cerdeno
- Department of Pathology and Laboratory Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Xinhua Zhan
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Wenbin Deng
- Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95817, USA
| | - Fuzheng Guo
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine (IPRM), Shriners Hospitals for Children, Sacramento, CA 95817, USA.
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12
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Kawamura A, Katayama Y, Nishiyama M, Shoji H, Tokuoka K, Ueta Y, Miyata M, Isa T, Miyakawa T, Hayashi-Takagi A, Nakayama KI. Oligodendrocyte dysfunction due to Chd8 mutation gives rise to behavioral deficits in mice. Hum Mol Genet 2021; 29:1274-1291. [PMID: 32142125 DOI: 10.1093/hmg/ddaa036] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/23/2020] [Accepted: 02/27/2020] [Indexed: 01/01/2023] Open
Abstract
Mutations in the gene encoding the chromatin remodeler CHD8 are strongly associated with autism spectrum disorder (ASD). CHD8 haploinsufficiency also results in autistic phenotypes in humans and mice. Although myelination defects have been observed in individuals with ASD, whether oligodendrocyte dysfunction is responsible for autistic phenotypes has remained unknown. Here we show that reduced expression of CHD8 in oligodendrocytes gives rise to abnormal behavioral phenotypes in mice. CHD8 was found to regulate the expression of many myelination-related genes and to be required for oligodendrocyte maturation and myelination. Ablation of Chd8 specifically in oligodendrocytes of mice impaired myelination, slowed action potential propagation and resulted in behavioral deficits including increased social interaction and anxiety-like behavior, with similar effects being apparent in Chd8 heterozygous mutant mice. Our results thus indicate that CHD8 is essential for myelination and that dysfunction of oligodendrocytes as a result of CHD8 haploinsufficiency gives rise to several neuropsychiatric phenotypes.
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Affiliation(s)
- Atsuki Kawamura
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Yuta Katayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Masaaki Nishiyama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Hirotaka Shoji
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Kota Tokuoka
- Department of Neuroscience, Graduate School of Medicine and Faculty of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Yoshifumi Ueta
- Department of Physiology I (Neurophysiology), Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Mariko Miyata
- Department of Physiology I (Neurophysiology), Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Tadashi Isa
- Department of Neuroscience, Graduate School of Medicine and Faculty of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Akiko Hayashi-Takagi
- Laboratory of Medical Neuroscience, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
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13
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Rett Syndrome: A Timely Review From Recognition to Current Clinical Approaches and Clinical Study Updates. Semin Pediatr Neurol 2021; 37:100881. [PMID: 33892852 DOI: 10.1016/j.spen.2021.100881] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/24/2021] [Accepted: 03/03/2021] [Indexed: 12/11/2022]
Abstract
Since the discovery of the genetic basis of Rett syndrome in 1999, our understanding has grown considerably both in the scientific and the clinical realms. In the last two decades, we have learned about the far-reaching effects of the aberrant MeCP2 protein, the growing list of involved genetic factors, and the genotype-phenotype clinical expression of common MECP2 mutations. This knowledge has led to several basic science research and clinical trials, focusing specifically on emerging treatments of Rett syndrome. As the pathophysiology behind the disease is better understood, treatments aimed at specific molecular targets will become available for clinicians to improve the life of individuals with Rett syndrome.
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14
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D'Mello SR. MECP2 and the Biology of MECP2 Duplication Syndrome. J Neurochem 2021; 159:29-60. [PMID: 33638179 DOI: 10.1111/jnc.15331] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 02/18/2021] [Indexed: 11/27/2022]
Abstract
MECP2 duplication syndrome (MDS), a rare X-linked genomic disorder affecting predominantly males, is caused by duplication of the chromosomal region containing the methyl CpG binding protein-2 (MECP2) gene, which encodes methyl-CpG-binding protein 2 (MECP2), a multi-functional protein required for proper brain development and maintenance of brain function during adulthood. Disease symptoms include severe motor and cognitive impairment, delayed or absent speech development, autistic features, seizures, ataxia, recurrent respiratory infections and shortened lifespan. The cellular and molecular mechanisms by which a relatively modest increase in MECP2 protein causes such severe disease symptoms are poorly understood and consequently there are no treatments available for this fatal disorder. This review summarizes what is known to date about the structure and complex regulation of MECP2 and its many functions in the developing and adult brain. Additionally, recent experimental findings on the cellular and molecular underpinnings of MDS based on cell culture and mouse models of the disorder are reviewed. The emerging picture from these studies is that MDS is a neurodegenerative disorder in which neurons die in specific parts of the central nervous system, including the cortex, hippocampus, cerebellum and spinal cord. Neuronal death likely results from astrocytic dysfunction, including a breakdown of glutamate homeostatic mechanisms. The role of elevations in the expression of glial acidic fibrillary protein (GFAP) in astrocytes and the microtubule-associated protein, Tau, in neurons to the pathogenesis of MDS is discussed. Lastly, potential therapeutic strategies to potentially treat MDS are discussed.
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15
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Fujita Y, Yamashita T. Alterations in Chromatin Structure and Function in the Microglia. Front Cell Dev Biol 2021; 8:626541. [PMID: 33553166 PMCID: PMC7858661 DOI: 10.3389/fcell.2020.626541] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/28/2020] [Indexed: 12/01/2022] Open
Abstract
Microglia are resident immune cells in the central nervous system (CNS). Microglia exhibit diversity in their morphology, density, electrophysiological properties, and gene expression profiles, and play various roles in neural development and adulthood in both physiological and pathological conditions. Recent transcriptomic analysis using bulk and single-cell RNA-seq has revealed that microglia can shift their gene expression profiles in various contexts, such as developmental stages, aging, and disease progression in the CNS, suggesting that the heterogeneity of microglia may be associated with their distinct functions. Epigenetic changes, including histone modifications and DNA methylation, coordinate gene expression, thereby contributing to the regulation of cellular state. In this review, we summarize the current knowledge regarding the epigenetic mechanisms underlying spatiotemporal and functional diversity of microglia that are altered in response to developmental stages and disease conditions. We also discuss how this knowledge may lead to advances in therapeutic approaches for diseases.
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Affiliation(s)
- Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.,Graduate School of Frontier Bioscience, Osaka University, Osaka, Japan.,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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16
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Jahn O, Siems SB, Kusch K, Hesse D, Jung RB, Liepold T, Uecker M, Sun T, Werner HB. The CNS Myelin Proteome: Deep Profile and Persistence After Post-mortem Delay. Front Cell Neurosci 2020; 14:239. [PMID: 32973451 PMCID: PMC7466725 DOI: 10.3389/fncel.2020.00239] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/07/2020] [Indexed: 12/14/2022] Open
Abstract
Myelin membranes are dominated by lipids while the complexity of their protein composition has long been considered to be low. However, numerous additional myelin proteins have been identified since. Here we revisit the proteome of myelin biochemically purified from the brains of healthy c56Bl/6N-mice utilizing complementary proteomic approaches for deep qualitative and quantitative coverage. By gel-free, label-free mass spectrometry, the most abundant myelin proteins PLP, MBP, CNP, and MOG constitute 38, 30, 5, and 1% of the total myelin protein, respectively. The relative abundance of myelin proteins displays a dynamic range of over four orders of magnitude, implying that PLP and MBP have overshadowed less abundant myelin constituents in initial gel-based approaches. By comparisons with published datasets we evaluate to which degree the CNS myelin proteome correlates with the mRNA and protein abundance profiles of myelin and oligodendrocytes. Notably, the myelin proteome displays only minor changes if assessed after a post-mortem delay of 6 h. These data provide the most comprehensive proteome resource of CNS myelin so far and a basis for addressing proteomic heterogeneity of myelin in mouse models and human patients with white matter disorders.
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Affiliation(s)
- Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Sophie B. Siems
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ramona B. Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Thomas Liepold
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Marina Uecker
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hauke B. Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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17
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Arthur-Farraj P, Moyon S. DNA methylation in Schwann cells and in oligodendrocytes. Glia 2020; 68:1568-1583. [PMID: 31958184 DOI: 10.1002/glia.23784] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/17/2019] [Accepted: 01/10/2020] [Indexed: 12/12/2022]
Abstract
DNA methylation is one of many epigenetic marks, which directly modifies base residues, usually cytosines, in a multiple-step cycle. It has been linked to the regulation of gene expression and alternative splicing in several cell types, including during cell lineage specification and differentiation processes. DNA methylation changes have also been observed during aging, and aberrant methylation patterns have been reported in several neurological diseases. We here review the role of DNA methylation in Schwann cells and oligodendrocytes, the myelin-forming glia of the peripheral and central nervous systems, respectively. We first address how methylation and demethylation are regulating myelinating cells' differentiation during development and repair. We then mention how DNA methylation dysregulation in diseases and cancers could explain their pathogenesis by directly influencing myelinating cells' proliferation and differentiation capacities.
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Affiliation(s)
- Peter Arthur-Farraj
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Sarah Moyon
- Neuroscience Initiative Advanced Science Research Center, CUNY, New York, New York
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18
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Vitamin D Supplementation Rescues Aberrant NF-κB Pathway Activation and Partially Ameliorates Rett Syndrome Phenotypes in Mecp2 Mutant Mice. eNeuro 2020; 7:ENEURO.0167-20.2020. [PMID: 32393583 PMCID: PMC7253640 DOI: 10.1523/eneuro.0167-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 01/28/2023] Open
Abstract
Rett syndrome (RTT) is a severe, progressive X-linked neurodevelopmental disorder caused by mutations in the transcriptional regulator MECP2. We previously identified aberrant NF-κB pathway upregulation in brains of Mecp2-null mice and demonstrated that genetically attenuating NF-κB rescues some characteristic neuronal RTT phenotypes. These results raised the intriguing question of whether NF-κB pathway inhibitors might provide a therapeutic avenue in RTT. Here, we investigate whether the known NF-κB pathway inhibitor vitamin D ameliorates neuronal phenotypes in Mecp2-mutant mice. Vitamin D deficiency is prevalent among RTT patients, and we find that Mecp2-null mice similarly have significantly reduced 25(OH)D serum levels compared with wild-type littermates. We identify that vitamin D rescues aberrant NF-κB pathway activation and reduced neurite outgrowth of Mecp2 knock-down cortical neurons in vitro. Further, dietary supplementation with vitamin D in early symptomatic male Mecp2 hemizygous null and female Mecp2 heterozygous mice ameliorates reduced neocortical dendritic morphology and soma size phenotypes and modestly improves reduced lifespan of Mecp2-nulls. These results elucidate fundamental neurobiology of RTT and provide foundation that NF-κB pathway inhibition might be a therapeutic target for RTT.
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19
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Pejhan S, Siu VM, Ang LC, Del Bigio MR, Rastegar M. Differential brain region-specific expression of MeCP2 and BDNF in Rett Syndrome patients: a distinct grey-white matter variation. Neuropathol Appl Neurobiol 2020; 46:735-750. [PMID: 32246495 DOI: 10.1111/nan.12619] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/03/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION AND OBJECTIVES Rett Syndrome (RTT) is a neurodevelopmental disorder caused by Methyl CpG Binding Protein 2 (MECP2) gene mutations. Previous studies of MeCP2 in the human brain showed variable and inconsistent mosaic-pattern immunolabelling, which has been interpreted as a reflection of activation-state variability. We aimed to study post mortem MeCP2 and BDNF (MeCP2 target) degradation and brain region-specific detection in relation to RTT pathophysiology. METHODS We investigated MeCP2 and BDNF stabilities in non-RTT human brains by immunohistochemical labelling and compared them in three brain regions of RTT and controls. RESULTS In surgically excised samples of human hippocampus and cerebellum, MeCP2 was universally detected. There was no significantly obvious difference between males and females. However, post mortem delay in autopsy samples had substantial influence on MeCP2 detection. Immunohistochemistry studies in RTT patients showed lower MeCP2 detection in glial cells of the white matter. Glial fibrillary acidic protein (GFAP) expression was also reduced in RTT brain samples without obvious change in myelin basic protein (MBP). Neurons did not show any noticeable decrease in MeCP2 detection. BDNF immunohistochemical detection showed an astroglial/endothelial pattern without noticeable difference between RTT and controls. CONCLUSIONS Our findings indicate that MeCP2 protein is widely expressed in mature human brain cells at all ages. However, our data points towards a possible white matter abnormality in RTT and highlights the importance of studying human RTT brain tissues in parallel with research on animal and cell models of RTT.
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Affiliation(s)
- S Pejhan
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - V M Siu
- Division of Medical Genetics, Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - L C Ang
- Department of Pathology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - M R Del Bigio
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - M Rastegar
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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20
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Kahanovitch U, Patterson KC, Hernandez R, Olsen ML. Glial Dysfunction in MeCP2 Deficiency Models: Implications for Rett Syndrome. Int J Mol Sci 2019; 20:ijms20153813. [PMID: 31387202 PMCID: PMC6696322 DOI: 10.3390/ijms20153813] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/01/2019] [Accepted: 08/02/2019] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome (RTT) is a rare, X-linked neurodevelopmental disorder typically affecting females, resulting in a range of symptoms including autistic features, intellectual impairment, motor deterioration, and autonomic abnormalities. RTT is primarily caused by the genetic mutation of the Mecp2 gene. Initially considered a neuronal disease, recent research shows that glial dysfunction contributes to the RTT disease phenotype. In the following manuscript, we review the evidence regarding glial dysfunction and its effects on disease etiology.
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Affiliation(s)
- Uri Kahanovitch
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences I Building Room 212, 970 Washington St. SW, Blacksburg, VA 24061, USA
| | - Kelsey C Patterson
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd., Birmingham, AL 35294, USA
| | - Raymundo Hernandez
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences I Building Room 212, 970 Washington St. SW, Blacksburg, VA 24061, USA
- Graduate Program in Translational Biology Medicine and Health, Virginia Tech, Roanoke, VL 24014, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences I Building Room 212, 970 Washington St. SW, Blacksburg, VA 24061, USA.
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21
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Bar E, Barak B. Microglia roles in synaptic plasticity and myelination in homeostatic conditions and neurodevelopmental disorders. Glia 2019; 67:2125-2141. [DOI: 10.1002/glia.23637] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Ela Bar
- The School of Psychological Sciences, Faculty of Social Sciences, and The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
- The School of Neurobiology, Biochemistry & Biophysics, Faculty of Life SciencesTel Aviv University Tel Aviv Israel
| | - Boaz Barak
- The School of Psychological Sciences, Faculty of Social Sciences, and The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
- The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
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22
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Mitochondrial Electron Transport Chain Complex Dysfunction in MeCP2 Knock-Down Astrocytes: Protective Effects of Quercetin Hydrate. J Mol Neurosci 2018; 67:16-27. [PMID: 30519865 DOI: 10.1007/s12031-018-1197-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/30/2022]
Abstract
Astrocytes play the central role in CNS metabolism to support neuronal functions. Mehyl-CpG-binding protein 2 (MeCP2) is the global transcription factor with differential expression in neuronal and non-neuronal cells. MeCP2 mutation and downstream detrimental effects have been reported in astrocytes also in MeCP2-associated neurodevelopmental disorder-Rett syndrome. Several studies have shown mitochondrial impairment linked to ROS production and reduced ATP synthesis in Rett patients and models, but consequences of MeCP2 deficiency on mitochondrial electron transport chain complexes in astrocytes and effect of known antioxidant quercetin aglycone has not yet been reported. The present study aimed to investigate effect of quercetin on mitochondrial functioning in MeCP2-deficient astrocytes. Our data show onefold upregulated Uqcrc1 and Ndufv2 gene expression, subtle change in protein expression, and significantly reduced mitochondrial respiratory chain complex-II and complex-III enzyme activities in MeCP2 knock-down astrocytes. Intracellular calcium robustly increased and mitochondrial membrane potential decreased, while no change in ROS was observed in MeCP2 knock-down astrocytes. Quercetin increased MeCP2 and normalized Uqcrc1 and Ndufv2 gene expression but did not modulate MeCP2 and Ndufv2 proteins expression. Interestingly, quercetin upregulated significantly the mitochondrial respiratory complex-II, complex-III, and complex-IV activities in dose-dependent manner. It also restored intracellular calcium level and mitochondrial membrane potential. In vitro observations suggest the beneficial effect of quercetin in mitochondrial functioning in MeCP2-deficient condition. There are no reports focusing on role of quercetin in mitochondrial function in MeCP2-deficient astrocytes, and these observations serve as preliminary data to evaluate quercetin's effects in vivo.
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23
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Sharma K, Singh J, Pillai PP. MeCP2 Differentially Regulate the Myelin MBP and PLP Protein Expression in Oligodendrocytes and C6 Glioma. J Mol Neurosci 2018; 65:343-350. [DOI: 10.1007/s12031-018-1112-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/25/2018] [Indexed: 12/21/2022]
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24
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Dong Q, Liu Q, Li R, Wang A, Bu Q, Wang KH, Chang Q. Mechanism and consequence of abnormal calcium homeostasis in Rett syndrome astrocytes. eLife 2018; 7:33417. [PMID: 29595472 PMCID: PMC5902163 DOI: 10.7554/elife.33417] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/28/2018] [Indexed: 12/21/2022] Open
Abstract
Astrocytes play an important role in Rett syndrome (RTT) disease progression. Although the non-cell-autonomous effect of RTT astrocytes on neurons was documented, cell-autonomous phenotypes and mechanisms within RTT astrocytes are not well understood. We report that spontaneous calcium activity is abnormal in RTT astrocytes in vitro, in situ, and in vivo. Such abnormal calcium activity is mediated by calcium overload in the endoplasmic reticulum caused by abnormal store operated calcium entry, which is in part dependent on elevated expression of TRPC4. Furthermore, the abnormal calcium activity leads to excessive activation of extrasynaptic NMDA receptors (eNMDARs) on neighboring neurons and increased network excitability in Mecp2 knockout mice. Finally, both the abnormal astrocytic calcium activity and the excessive activation of eNMDARs are caused by Mecp2 deletion in astrocytes in vivo. Our findings provide evidence that abnormal calcium homeostasis is a key cell-autonomous phenotype in RTT astrocytes, and reveal its mechanism and consequence.
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Affiliation(s)
- Qiping Dong
- Waisman Center, University of Wisconsin-Madison, Madison, United States
| | - Qing Liu
- Unit on Neural Circuits and Adaptive Behaviors, National Institute of Mental Health, Bethesda, United States
| | - Ronghui Li
- Waisman Center, University of Wisconsin-Madison, Madison, United States
| | - Anxin Wang
- Waisman Center, University of Wisconsin-Madison, Madison, United States
| | - Qian Bu
- Waisman Center, University of Wisconsin-Madison, Madison, United States
| | - Kuan Hong Wang
- Unit on Neural Circuits and Adaptive Behaviors, National Institute of Mental Health, Bethesda, United States
| | - Qiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, United States.,Department of Medical Genetics, University of Wisconsin-Madison, Madison, United States.,Department of Neurology, University of Wisconsin-Madison, Madison, United States
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25
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Abstract
Rett Syndrome is a severe neurological disorder mainly due to
de novo mutations in the methyl-CpG-binding protein 2 gene (
MECP2). Mecp2 is known to play a role in chromatin organization and transcriptional regulation. In this review, we report the latest advances on the molecular function of Mecp2 and the new animal and cellular models developed to better study Rett syndrome. Finally, we present the latest innovative therapeutic approaches, ranging from classical pharmacology to correct symptoms to more innovative approaches intended to cure the pathology.
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Affiliation(s)
- Yann Ehinger
- Aix Marseille Univ, INSERM, MMG, 13385 Marseille, France
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26
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Correale J, Ysrraelit MC, Benarroch EE. Metabolic coupling of axons and glial cells. Neurology 2018; 90:737-744. [DOI: 10.1212/wnl.0000000000005339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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27
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Patil SS, Suresh KP, Saha S, Prajapati A, Hemadri D, Roy P. Meta-analysis of classical swine fever prevalence in pigs in India: A 5-year study. Vet World 2018; 11:297-303. [PMID: 29657420 PMCID: PMC5891843 DOI: 10.14202/vetworld.2018.297-303] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 01/18/2018] [Indexed: 11/24/2022] Open
Abstract
Aim: The aim of the study was to determine the overall prevalence of classical swine fever (CSF) in pigs in India, through a systematic review and meta-analysis of published data. Materials and Methods: Consortium for e-Resources in Agriculture, India, Google Scholar, PubMed, annual reports of All India Coordinated Research Project on Animal Disease Monitoring and Surveillance, and All India Animal Disease database of NIVEDI (NADRES) were used for searching and retrieval of CSF prevalence data (seroprevalence, virus antigen, and virus nucleic acid detection) in India using a search strategy combining keywords and related database-specific subject terms from January 2011 to December 2015 in English only. Results: A total of 22 data reports containing 6,158 samples size from 18 states of India were used for the quantitative synthesis, and overall 37% (95% confidence interval [CI]=0.24, 0.51) CSF prevalence in India was estimated. The data were classified into 4 different geographical zones of the country: 20% (95% CI=0.05, 0.55), 31% (95% CI=0.18, 0.47), 55% (95% CI=0.32, 0.76), and 34% (95% CI=0.14, 0.62). CSF prevalence was estimated in northern, eastern, western, and southern regions, respectively. Conclusion: This study indicates that overall prevalence of CSF in India is much lower than individual published reports.
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Affiliation(s)
- S S Patil
- Indian Council of Agricultural Research - National Institute of Veterinary Epidemiology and Disease Informatics (ICAR-NIVEDI), PBNO-6450, Yelahanka, Bengaluru, Karnataka, India
| | - K P Suresh
- Indian Council of Agricultural Research - National Institute of Veterinary Epidemiology and Disease Informatics (ICAR-NIVEDI), PBNO-6450, Yelahanka, Bengaluru, Karnataka, India
| | - S Saha
- Indian Council of Agricultural Research - National Institute of Veterinary Epidemiology and Disease Informatics (ICAR-NIVEDI), PBNO-6450, Yelahanka, Bengaluru, Karnataka, India
| | - A Prajapati
- Indian Council of Agricultural Research - National Institute of Veterinary Epidemiology and Disease Informatics (ICAR-NIVEDI), PBNO-6450, Yelahanka, Bengaluru, Karnataka, India
| | - D Hemadri
- Indian Council of Agricultural Research - National Institute of Veterinary Epidemiology and Disease Informatics (ICAR-NIVEDI), PBNO-6450, Yelahanka, Bengaluru, Karnataka, India
| | - P Roy
- Indian Council of Agricultural Research - National Institute of Veterinary Epidemiology and Disease Informatics (ICAR-NIVEDI), PBNO-6450, Yelahanka, Bengaluru, Karnataka, India
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Kyle SM, Vashi N, Justice MJ. Rett syndrome: a neurological disorder with metabolic components. Open Biol 2018; 8:170216. [PMID: 29445033 PMCID: PMC5830535 DOI: 10.1098/rsob.170216] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 01/18/2018] [Indexed: 02/06/2023] Open
Abstract
Rett syndrome (RTT) is a neurological disorder caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2), a ubiquitously expressed transcriptional regulator. Despite remarkable scientific progress since its discovery, the mechanism by which MECP2 mutations cause RTT symptoms is largely unknown. Consequently, treatment options for patients are currently limited and centred on symptom relief. Thought to be an entirely neurological disorder, RTT research has focused on the role of MECP2 in the central nervous system. However, the variety of phenotypes identified in Mecp2 mutant mouse models and RTT patients implicate important roles for MeCP2 in peripheral systems. Here, we review the history of RTT, highlighting breakthroughs in the field that have led us to present day. We explore the current evidence supporting metabolic dysfunction as a component of RTT, presenting recent studies that have revealed perturbed lipid metabolism in the brain and peripheral tissues of mouse models and patients. Such findings may have an impact on the quality of life of RTT patients as both dietary and drug intervention can alter lipid metabolism. Ultimately, we conclude that a thorough knowledge of MeCP2's varied functional targets in the brain and body will be required to treat this complex syndrome.
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Affiliation(s)
- Stephanie M Kyle
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada M5G 0A4
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Neeti Vashi
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada M5G 0A4
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A1
| | - Monica J Justice
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada M5G 0A4
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A1
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Sharma K, Singh J, Frost EE, Pillai PP. MeCP2 in central nervous system glial cells: current updates. Acta Neurobiol Exp (Wars) 2018. [DOI: 10.21307/ane-2018-007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Pacheco NL, Heaven MR, Holt LM, Crossman DK, Boggio KJ, Shaffer SA, Flint DL, Olsen ML. RNA sequencing and proteomics approaches reveal novel deficits in the cortex of Mecp2-deficient mice, a model for Rett syndrome. Mol Autism 2017; 8:56. [PMID: 29090078 PMCID: PMC5655833 DOI: 10.1186/s13229-017-0174-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 10/02/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused by mutations in the transcriptional regulator MeCP2. Much of our understanding of MeCP2 function is derived from transcriptomic studies with the general assumption that alterations in the transcriptome correlate with proteomic changes. Advances in mass spectrometry-based proteomics have facilitated recent interest in the examination of global protein expression to better understand the biology between transcriptional and translational regulation. METHODS We therefore performed the first comprehensive transcriptome-proteome comparison in a RTT mouse model to elucidate RTT pathophysiology, identify potential therapeutic targets, and further our understanding of MeCP2 function. The whole cortex of wild-type and symptomatic RTT male littermates (n = 4 per genotype) were analyzed using RNA-sequencing and data-independent acquisition liquid chromatography tandem mass spectrometry. Ingenuity® Pathway Analysis was used to identify significantly affected pathways in the transcriptomic and proteomic data sets. RESULTS Our results indicate these two "omics" data sets supplement one another. In addition to confirming previous works regarding mRNA expression in Mecp2-deficient animals, the current study identified hundreds of novel protein targets. Several selected protein targets were validated by Western blot analysis. These data indicate RNA metabolism, proteostasis, monoamine metabolism, and cholesterol synthesis are disrupted in the RTT proteome. Hits common to both data sets indicate disrupted cellular metabolism, calcium signaling, protein stability, DNA binding, and cytoskeletal cell structure. Finally, in addition to confirming disrupted pathways and identifying novel hits in neuronal structure and synaptic transmission, our data indicate aberrant myelination, inflammation, and vascular disruption. Intriguingly, there is no evidence of reactive gliosis, but instead, gene, protein, and pathway analysis suggest astrocytic maturation and morphological deficits. CONCLUSIONS This comparative omics analysis supports previous works indicating widespread CNS dysfunction and may serve as a valuable resource for those interested in cellular dysfunction in RTT.
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Affiliation(s)
- Natasha L. Pacheco
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd, Birmingham, AL 35294 USA
| | - Michael R. Heaven
- Vulcan Analytical, LLC, 1500 1st Ave. North, Birmingham, AL 35203 USA
| | - Leanne M. Holt
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd, Birmingham, AL 35294 USA
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences Building Room 213, 970 Washington St. SW, Blacksburg, VA 24061 USA
| | - David K. Crossman
- UAB Heflin Center for Genomic Science, Department of Genetics, University of Alabama at Birmingham, Kaul 424A, 1720 2nd Ave. South, Birmingham, AL 35294 USA
| | - Kristin J. Boggio
- Proteomics and Mass Spectrometry Facility, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 222 Maple Ave., Fuller Building, Shrewsbury, MA 01545 USA
| | - Scott A. Shaffer
- Proteomics and Mass Spectrometry Facility, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 222 Maple Ave., Fuller Building, Shrewsbury, MA 01545 USA
| | - Daniel L. Flint
- Luxumbra Strategic Research, LLC, 1331 South Eads St, Arlington, VA 22202 USA
| | - Michelle L. Olsen
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd, Birmingham, AL 35294 USA
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences Building Room 213, 970 Washington St. SW, Blacksburg, VA 24061 USA
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31
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Jin XR, Chen XS, Xiao L. MeCP2 Deficiency in Neuroglia: New Progress in the Pathogenesis of Rett Syndrome. Front Mol Neurosci 2017; 10:316. [PMID: 29046627 PMCID: PMC5632713 DOI: 10.3389/fnmol.2017.00316] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 09/19/2017] [Indexed: 01/24/2023] Open
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disease predominantly caused by mutations of the methyl-CpG-binding protein 2 (MeCP2) gene. Generally, RTT has been attributed to neuron-centric dysfunction. However, increasing evidence has shown that glial abnormalities are also involved in the pathogenesis of RTT. Mice that are MeCP2-null specifically in glial cells showed similar behavioral and/or neuronal abnormalities as those found in MeCP2-null mice, a mouse model of RTT. MeCP2 deficiency in astrocytes impacts the expression of glial intermediate filament proteins such as fibrillary acidic protein (GFAP) and S100 and induces neuron toxicity by disturbing glutamate metabolism or enhancing microtubule instability. MeCP2 deficiency in oligodendrocytes (OLs) results in down-regulation of myelin gene expression and impacts myelination. While MeCP2-deficient microglia cells fail in response to environmental stimuli, release excessive glutamate, and aggravate impairment of the neuronal circuit. In this review, we mainly focus on the progress in determining the role of MeCP2 in glial cells involved in RTT, which may provide further insight into a therapeutic intervention for RTT.
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Affiliation(s)
- Xu-Rui Jin
- Department of Histology and Embryology, Faculty of Basic Medicine, Collaborative Program for Brain Research, Third Military Medical University, Chongqing, China.,The Cadet Brigade of Clinic Medicine, Third Military Medical University, Chongqing, China
| | - Xing-Shu Chen
- Department of Histology and Embryology, Faculty of Basic Medicine, Collaborative Program for Brain Research, Third Military Medical University, Chongqing, China
| | - Lan Xiao
- Department of Histology and Embryology, Faculty of Basic Medicine, Collaborative Program for Brain Research, Third Military Medical University, Chongqing, China
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32
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Valacchi G, Pecorelli A, Cervellati C, Hayek J. 4-hydroxynonenal protein adducts: Key mediator in Rett syndrome oxinflammation. Free Radic Biol Med 2017; 111:270-280. [PMID: 28063942 DOI: 10.1016/j.freeradbiomed.2016.12.045] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 12/24/2016] [Accepted: 12/30/2016] [Indexed: 12/13/2022]
Abstract
In the last 15 years a strong correlation between oxidative stress (OxS) and Rett syndrome (RTT), a rare neurodevelopmental disorder known to be caused in 95% of the cases, by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, has been well documented. Here, we revised, summarized and discussed the current knowledge on the role of lipid peroxidation byproducts, with special emphasis on 4-hydroxynonenal (4HNE), in RTT pathophysiology. The posttranslational modifications of proteins via 4HNE, known as 4HNE protein adducts (4NHE-PAs), causing detrimental effects on protein functions, appear to contribute to the clinical severity of the syndrome, since their levels increase significantly during the subsequent 4 clinical stages, reaching the maximum degree at stage 4, represented by a late motor deterioration. In addition, 4HNE-PA are only partially removed due to the compromised functionality of the proteasome activity, contributing therefore to the cellular damage in RTT. All this will lead to a characteristic subclinical inflammation, defined "OxInflammation", derived by a positive feedback loop between OxS byproducts and inflammatory mediators that in a long run further aggravates the clinical features of RTT patients. Therefore, in a pathology completely orphan of any therapy, aiming 4HNE as a therapeutic target could represent a coadjuvant treatment with some beneficial impact in these patients..
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Affiliation(s)
- Giuseppe Valacchi
- Plants for Human Health Institute, Department of Animal Sciences, NC State University, NC Research Campus, 600 Laureate Way, Kannapolis, NC 28081, USA; Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy.
| | - Alessandra Pecorelli
- Plants for Human Health Institute, Department of Animal Sciences, NC State University, NC Research Campus, 600 Laureate Way, Kannapolis, NC 28081, USA; Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Carlo Cervellati
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Joussef Hayek
- Child Neuropsychiatry Unit, University Hospital, AOUS, Viale Mario Bracci, 53100 Siena, Italy
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33
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Lüders KA, Patzig J, Simons M, Nave KA, Werner HB. Genetic dissection of oligodendroglial and neuronalPlp1function in a novel mouse model of spastic paraplegia type 2. Glia 2017; 65:1762-1776. [DOI: 10.1002/glia.23193] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Katja A. Lüders
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Julia Patzig
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Mikael Simons
- Cellular Neuroscience; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Hauke B. Werner
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
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34
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Increased Mitochondrial Mass and Cytosolic Redox Imbalance in Hippocampal Astrocytes of a Mouse Model of Rett Syndrome: Subcellular Changes Revealed by Ratiometric Imaging of JC-1 and roGFP1 Fluorescence. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3064016. [PMID: 28894505 PMCID: PMC5574314 DOI: 10.1155/2017/3064016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 06/16/2017] [Accepted: 06/27/2017] [Indexed: 12/21/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder with mutations in the MECP2 gene. Mostly girls are affected, and an apparently normal development is followed by cognitive impairment, motor dysfunction, epilepsy, and irregular breathing. Various indications suggest mitochondrial dysfunction. In Rett mice, brain ATP levels are reduced, mitochondria are leaking protons, and respiratory complexes are dysregulated. Furthermore, we found in MeCP2-deficient mouse (Mecp2−/y) hippocampus an intensified mitochondrial metabolism and ROS generation. We now used emission ratiometric 2-photon imaging to assess mitochondrial morphology, mass, and membrane potential (ΔΨm) in Mecp2−/y hippocampal astrocytes. Cultured astrocytes were labeled with the ΔΨm marker JC-1, and semiautomated analyses yielded the number of mitochondria per cell, their morphology, and ΔΨm. Mecp2−/y astrocytes contained more mitochondria than wild-type (WT) cells and were more oxidized. Mitochondrial size, ΔΨm, and vulnerability to pharmacological challenge did not differ. The antioxidant Trolox opposed the oxidative burden and decreased the mitochondrial mass, thereby dampening the differences among WT and Mecp2−/y astrocytes; mitochondrial size and ΔΨm were not markedly affected. In conclusion, mitochondrial alterations and redox imbalance in RTT also involve astrocytes. Mitochondria are more numerous in Mecp2−/y than in WT astrocytes. As this genotypic difference is abolished by Trolox, it seems linked to the oxidative stress in RTT.
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35
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Parikh ZS, Tripathi A, Pillai PP. Differential Regulation of MeCP2 Phosphorylation by Laminin in Oligodendrocytes. J Mol Neurosci 2017; 62:309-317. [PMID: 28616777 DOI: 10.1007/s12031-017-0939-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/06/2017] [Indexed: 10/19/2022]
Abstract
Oligodendrocytes (OLGs) are the myelinating cells of the central nervous system (CNS), and its proper differentiation is crucial for normal functioning of neurons. Methyl-CpG-binding protein 2 (MeCP2) is a multifunctional methylated DNA binding protein; mutation of which causes Rett syndrome, a severe neurodevelopmental disorder. Previously, we reported that MeCP2 is expressed in all the stages of oligodendrocyte development, and also shown the role of MeCP2 as a transcription regulator of myelin genes in OLGs. The expression and function of MeCP2 phosphorylation at S80 (pS80MeCP2) has been well studied in neurons and astrocytes; however, there is no data so far available in OLGs regarding pS80MeCP2. Certain developmental stimuli such as growth factors and extracellular matrix (ECM) protein play important role in OLG development. In the present study, we have examined the effects of external stimuli (growth factors (GFs) and extracellular matrix (ECMs)) on S80 phosphorylation of MeCP2 in N19 oligodendroglial cells (N19 OLGs). This study provides the first evidence that laminin (LN) differentially regulates the expression of pS80MeCP2 in immature and mature N19 OLGs. Thus, MeCP2 is phosphorylated in a stimulus-dependent manner during oligodendrocyte development, and thereby, it may regulate the oligodendrocyte behavior.
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Affiliation(s)
- Zalak S Parikh
- Division of Neurobiology, Department of Zoology, Faculty of Science, The M. S. University of Baroda, Vadodara, Gujarat, 390002, India
| | - Ashutosh Tripathi
- Division of Neurobiology, Department of Zoology, Faculty of Science, The M. S. University of Baroda, Vadodara, Gujarat, 390002, India
| | - Prakash P Pillai
- Division of Neurobiology, Department of Zoology, Faculty of Science, The M. S. University of Baroda, Vadodara, Gujarat, 390002, India.
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36
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Krishnaraj R, Ho G, Christodoulou J. RettBASE: Rett syndrome database update. Hum Mutat 2017; 38:922-931. [PMID: 28544139 DOI: 10.1002/humu.23263] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/21/2016] [Accepted: 07/27/2016] [Indexed: 12/20/2022]
Abstract
Rett syndrome (RTT) is an X-linked progressive neurodevelopmental disorder that primarily affects females. Mutations in the MECP2 gene have been attributed as the major genetic cause of RTT. Recently, mutations in CDKL5 and FOXG1 genes have also been suggested to give rise to RTT, although subsequent more extensive studies suggest that diseases resulting from mutations in these two genes should be considered as distinct clinical entities. While the genetic basis for the RTT has been recognized, so far there is no effective cure for the disease and the treatments available are mainly aimed at ameliorating clinical problems associated with the disorder. The swift identification of the mutations in children is crucial for pursuing the best therapeutic care. RettBASE was created in 2002 as a MECP2 variant database and has grown to become a comprehensive variant database for RTT and related clinical phenotypes, containing a curated collection of variants for MECP2, CDKL5, and FOXG1 genes. Here, we describe the development and growth of RettBASE after its inception in 2001. Currently, RettBASE holds a total of 4,668 variants in MECP2, 498 variants in CDKL5, and 64 variants in FOXG1.
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Affiliation(s)
- Rahul Krishnaraj
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia
| | - Gladys Ho
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia.,Disciplines of Child and Adolescent, Child Health, University of Sydney, Sydney, Australia
| | - John Christodoulou
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia.,Disciplines of Child and Adolescent, Child Health, University of Sydney, Sydney, Australia.,Genetic Medicine, Sydney Medical School, University of Sydney, Sydney, Australia.,Neurodevelopmental Genomics Research Group, Murdoch Childrens Research Institute and Department of Paediatrics, Melbourne Medical School, University of Melbourne, Melbourne, Australia
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37
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Zhao D, Mokhtari R, Pedrosa E, Birnbaum R, Zheng D, Lachman HM. Transcriptome analysis of microglia in a mouse model of Rett syndrome: differential expression of genes associated with microglia/macrophage activation and cellular stress. Mol Autism 2017; 8:17. [PMID: 28367307 PMCID: PMC5372344 DOI: 10.1186/s13229-017-0134-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/17/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a severe, neurodevelopmental disorder primarily affecting girls, characterized by progressive loss of cognitive, social, and motor skills after a relatively brief period of typical development. It is usually due to de novo loss of function mutations in the X-linked gene, MeCP2, which codes for the gene expression and chromatin regulator, methyl-CpG binding protein 2. Although the behavioral phenotype appears to be primarily due to neuronal Mecp2 deficiency in mice, other cell types, including astrocytes and oligodendrocytes, also appear to contribute to some aspects of the RTT phenotype. In addition, microglia may also play a role. However, the effect of Mecp2 deficiency in microglia on RTT pathogenesis is controversial. METHODS In the current study, we applied whole transcriptome analysis using RNA-seq to gain insight into molecular pathways in microglia that might be dysregulated during the transition, in female mice heterozygous for an Mecp2-null allele (Mecp2+/-; Het), from the pre-phenotypic (5 weeks) to the phenotypic phases (24 weeks). RESULTS We found a significant overlap in differentially expressed genes (DEGs) with genes involved in regulating the extracellular matrix, and those that are activated or inhibited when macrophages and microglia are stimulated towards the M1 and M2 activation states. However, the M1- and M2-associated genes were different in the 5- and 24-week samples. In addition, a substantial decrease in the expression of nine members of the heat shock protein (HSP) family was found in the 5-week samples, but not at 24 weeks. CONCLUSIONS These findings suggest that microglia from pre-phenotypic and phenotypic female mice are activated in a manner different from controls and that pre-phenotypic female mice may have alterations in their capacity to response to heat stress and other stressors that function through the HSP pathway.
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Affiliation(s)
- Dejian Zhao
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Ryan Mokhtari
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Rayna Birnbaum
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Neurology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Herbert M Lachman
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
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Shulyakova N, Andreazza AC, Mills LR, Eubanks JH. Mitochondrial Dysfunction in the Pathogenesis of Rett Syndrome: Implications for Mitochondria-Targeted Therapies. Front Cell Neurosci 2017; 11:58. [PMID: 28352216 PMCID: PMC5348512 DOI: 10.3389/fncel.2017.00058] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/20/2017] [Indexed: 01/20/2023] Open
Abstract
First described over 50 years ago, Rett syndrome (RTT) is a neurodevelopmental disorder caused primarily by mutations of the X-linked MECP2 gene. RTT affects predominantly females, and has a prevalence of roughly 1 in every 10,000 female births. Prior to the discovery that mutations of MECP2 are the leading cause of RTT, there were suggestions that RTT could be a mitochondrial disease. In fact, several reports documented altered mitochondrial structure, and deficiencies in mitochondrial enzyme activity in different cells or tissues derived from RTT patients. With the identification of MECP2 as the causal gene, interest largely shifted toward defining the normal function of MeCP2 in the brain, and how its absence affects the neurodevelopment and neurophysiology. Recently, though, interest in studying mitochondrial function in RTT has been reignited, at least in part due to observations suggesting systemic oxidative stress does play a contributing role in RTT pathogenesis. Here we review data relating to mitochondrial alterations at the structural and functional levels in RTT patients and model systems, and present a hypothesis for how the absence of MeCP2 could lead to altered mitochondrial function and elevated levels of cellular oxidative stress. Finally, we discuss the prospects for treating RTT using interventions that target specific aspects of mitochondrial dysfunction and/or oxidative stress.
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Affiliation(s)
- Natalya Shulyakova
- Division of Genetics and Development, Krembil Research Institute, University Health NetworkToronto, ON, Canada; Department of Physiology, University of TorontoToronto, ON, Canada
| | - Ana C Andreazza
- Department of Pharmacology, University of Toronto Toronto, ON, Canada
| | - Linda R Mills
- Department of Physiology, University of Toronto Toronto, ON, Canada
| | - James H Eubanks
- Division of Genetics and Development, Krembil Research Institute, University Health NetworkToronto, ON, Canada; Department of Physiology, University of TorontoToronto, ON, Canada; Institute of Medical Sciences, University of TorontoToronto, ON, Canada; Department of Surgery (Neurosurgery), University of TorontoToronto, ON, Canada
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39
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Fattorini G, Melone M, Sánchez-Gómez MV, Arellano RO, Bassi S, Matute C, Conti F. GAT-1 mediated GABA uptake in rat oligodendrocytes. Glia 2017; 65:514-522. [PMID: 28071826 DOI: 10.1002/glia.23108] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 11/30/2016] [Accepted: 12/05/2016] [Indexed: 01/18/2023]
Abstract
Stimulated by the results of a recent paper on the effects of tiagabine, a selective inhibitor of the main GABA transporter GAT-1, on oligodendrogenesis, we verified the possibility that GAT-1 may be expressed in oligodendrocytes using immunocytochemical methods and functional assays. Light microscopic analysis of the subcortical white matter of all animals revealed the presence of numerous GAT-1+ cells of different size (from 3 to 29 µm) and morphology. An electron microscope analysis revealed that, besides fibrous astrocytes and interstitial neurons, GAT-1 immunoreactivity was present in immature and mature oligodendrocytes. Co-localization studies between GAT-1 and markers specific for oligodendrocytes (NG2 and RIP) showed that about 12% of GAT-1 positive cells in the white matter were immature oligodendrocytes, while about 15% were mature oligodendrocytes. In vitro functional assays showed that oligodendrocytes exhibit tiagabine-sensitive Na+ -dependent GABA uptake. Although relationships between GABA and oligodendrocytes have been known for many years, this is the first demonstration that GAT-1 is expressed in oligodendrocytes. The present results on the one hand definitely closes the era of "neuronal" and "glial" GABA transporters, on the other they suggest that oligodendrocytes may contribute to pathophysiology of the several diseases in which GAT-1 have been implicated to date. GLIA 2017;65:514-522.
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Affiliation(s)
- Giorgia Fattorini
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, 60026, Italy.,Center for Neurobiology of Aging, INRCA IRCCS, Ancona, 60121, Italy
| | - Marcello Melone
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, 60026, Italy.,Center for Neurobiology of Aging, INRCA IRCCS, Ancona, 60121, Italy
| | - María Victoria Sánchez-Gómez
- Achucarro Basque Center for Neuroscience, CIBERNED, and Departamento de Neurociencias, Universidad del País Vasco, Leioa, 48940, Spain
| | - Rogelio O Arellano
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Silvia Bassi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, 60026, Italy
| | - Carlos Matute
- Achucarro Basque Center for Neuroscience, CIBERNED, and Departamento de Neurociencias, Universidad del País Vasco, Leioa, 48940, Spain
| | - Fiorenzo Conti
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, 60026, Italy.,Center for Neurobiology of Aging, INRCA IRCCS, Ancona, 60121, Italy.,Fondazione di Medicina Molecolare, Università Politecnica delle Marche, Ancona, 60026, Italy
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Leonard H, Cobb S, Downs J. Clinical and biological progress over 50 years in Rett syndrome. Nat Rev Neurol 2016; 13:37-51. [PMID: 27934853 DOI: 10.1038/nrneurol.2016.186] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the 50 years since Andreas Rett first described the syndrome that came to bear his name, and is now known to be caused by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, a compelling blend of astute clinical observations and clinical and laboratory research has substantially enhanced our understanding of this rare disorder. Here, we document the contributions of the early pioneers in Rett syndrome (RTT) research, and describe the evolution of knowledge in terms of diagnostic criteria, clinical variation, and the interplay with other Rett-related disorders. We provide a synthesis of what is known about the neurobiology of MeCP2, considering the lessons learned from both cell and animal models, and how they might inform future clinical trials. With a focus on the core criteria, we examine the relationships between genotype and clinical severity. We review current knowledge about the many comorbidities that occur in RTT, and how genotype may modify their presentation. We also acknowledge the important drivers that are accelerating this research programme, including the roles of research infrastructure, international collaboration and advocacy groups. Finally, we highlight the major milestones since 1966, and what they mean for the day-to-day lives of individuals with RTT and their families.
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Affiliation(s)
- Helen Leonard
- Telethon Kids Institute, 100 Roberts Road, Subiaco, Perth, Western Australia 6008, Australia
| | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Jenny Downs
- Telethon Kids Institute, 100 Roberts Road, Subiaco, Perth, Western Australia 6008, Australia
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41
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Bednarczyk J, Dębski KJ, Bot AM, Lukasiuk K. MBD3 expression and DNA binding patterns are altered in a rat model of temporal lobe epilepsy. Sci Rep 2016; 6:33736. [PMID: 27650712 PMCID: PMC5030630 DOI: 10.1038/srep33736] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 09/02/2016] [Indexed: 12/18/2022] Open
Abstract
The aim of the present study was to examine involvement of MBD3 (methyl-CpG-binding domain protein 3), a protein involved in reading DNA methylation patterns, in epileptogenesis and epilepsy. We used a well-characterized rat model of temporal lobe epilepsy that is triggered by status epilepticus, evoked by electrical stimulation of the amygdala. Stimulated and sham-operated animals were sacrificed 14 days after stimulation. We found that MBD3 transcript was present in neurons, oligodendrocytes, and astrocytes in both control and epileptic animals. We detected the nuclear localization of MBD3 protein in neurons, mature oligodendrocytes, and a subpopulation of astrocytes but not in microglia. Amygdala stimulation significantly increased the level of MBD3 immunofluorescence. Immunoprecipitation followed by mass spectrometry and Western blot revealed that MBD3 in the adult brain assembles the NuRD complex, which also contains MTA2, HDAC2, and GATAD2B. Using chromatin immunoprecipitation combined with deep sequencing, we observed differences in the occupancy of DNA regions by MBD3 protein between control and stimulated animals. This was not followed by subsequent changes in the mRNA expression levels of selected MBD3 targets. Our data demonstrate for the first time alterations in the MBD3 expression and DNA occupancy in the experimental model of epilepsy.
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Affiliation(s)
- Joanna Bednarczyk
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Konrad J. Dębski
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
- Laboratory of Bioinformatics, Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Anna M. Bot
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Katarzyna Lukasiuk
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
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Kaufmann WE, Stallworth JL, Everman DB, Skinner SA. Neurobiologically-based treatments in Rett syndrome: opportunities and challenges. Expert Opin Orphan Drugs 2016; 4:1043-1055. [PMID: 28163986 PMCID: PMC5214376 DOI: 10.1080/21678707.2016.1229181] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/23/2016] [Indexed: 12/14/2022]
Abstract
Introduction: Rett syndrome (RTT) is an X-linked neurodevelopmental disorder that primarily affects females, typically resulting in a period of developmental regression in early childhood followed by stabilization and severe chronic cognitive, behavioral, and physical disability. No known treatment exists beyond symptomatic management, and while insights into the genetic cause, pathophysiology, neurobiology, and natural history of RTT have been gained, many challenges remain. Areas covered: Based on a comprehensive survey of the primary literature on RTT, this article describes and comments upon the general and unique features of the disorder, genetic and neurobiological bases of drug development, and the history of clinical trials in RTT, with an emphasis on drug trial design, outcome measures, and implementation. Expert opinion: Neurobiologically based drug trials are the ultimate goal in RTT, and due to the complexity and global nature of the disorder, drugs targeting both general mechanisms (e.g., growth factors) and specific systems (e.g., glutamate modulators) could be effective. Trial design should optimize data on safety and efficacy, but selection of outcome measures with adequate measurement properties, as well as innovative strategies, such as those enhancing synaptic plasticity and use of biomarkers, are essential for progress in RTT and other neurodevelopmental disorders.
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Affiliation(s)
- Walter E Kaufmann
- Center for Translational Research, Greenwood Genetic Center, Greenwood, SC, USA; Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | | | - David B Everman
- Center for Translational Research, Greenwood Genetic Center , Greenwood , SC , USA
| | - Steven A Skinner
- Center for Translational Research, Greenwood Genetic Center , Greenwood , SC , USA
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43
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Cronk JC, Derecki NC, Litvak V, Kipnis J. Unexpected cellular players in Rett syndrome pathology. Neurobiol Dis 2016; 92:64-71. [PMID: 25982834 PMCID: PMC4644494 DOI: 10.1016/j.nbd.2015.05.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/30/2015] [Accepted: 05/08/2015] [Indexed: 12/31/2022] Open
Abstract
Rett syndrome is a devastating neurodevelopmental disorder, primarily caused by mutations of methyl CpG-binding protein 2 (MeCP2). Although the genetic cause of disease was identified over a decade ago, a significant gap still remains in both our clinical and scientific understanding of its pathogenesis. Neurons are known to be primary players in pathology, with their dysfunction being the key in Rett syndrome. While studies in mice have demonstrated a clear causative - and potential therapeutic - role for neurons in Rett syndrome, recent work has suggested that other tissues also contribute significantly to progression of the disease. Indeed, Rett syndrome is known to present with several common peripheral pathologies, such as osteopenia, scoliosis, gastrointestinal problems including nutritional defects, and general growth deficit. Mouse models assessing the potential role of non-neuronal cell types have confirmed both roles in disease and potential therapeutic targets. A new picture is emerging in which neurons both initiate and drive pathology, while dysfunction of other cell types and peripheral tissues exacerbate disease, possibly amplifying further neurologic problems, and ultimately result in a positive feedback loop of progressively worsening symptoms. Here, we review what is known about neuronal and non-neuronal cell types, and discuss how this new, integrative understanding of the disease may allow for additional clinical and scientific pathways for treating and understanding Rett syndrome.
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Affiliation(s)
- James C Cronk
- Center for Brain Immunology and Glia, Department of Neuroscience, Graduate Program in Neuroscience and Medical Scientist Training Program, University of Virginia, Charlottesville, VA 22908, USA.
| | - Noel C Derecki
- Center for Brain Immunology and Glia, Department of Neuroscience, Graduate Program in Neuroscience and Medical Scientist Training Program, University of Virginia, Charlottesville, VA 22908, USA
| | - Vladimir Litvak
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia, Department of Neuroscience, Graduate Program in Neuroscience and Medical Scientist Training Program, University of Virginia, Charlottesville, VA 22908, USA.
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44
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Liu J, Moyon S, Hernandez M, Casaccia P. Epigenetic control of oligodendrocyte development: adding new players to old keepers. Curr Opin Neurobiol 2016; 39:133-8. [PMID: 27308779 PMCID: PMC4987162 DOI: 10.1016/j.conb.2016.06.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/27/2016] [Accepted: 06/01/2016] [Indexed: 01/08/2023]
Abstract
Emerging and strengthening evidence suggests an important role of myelin in plasticity and axonal survival. However, the mechanisms regulating progression from oligodendrocyte progenitor cells (OPCs) to myelinating oligodendrocytes remain only partially understood. A series of overlapping yet distinct epigenetic events occur as a proliferating OPC exits the cell cycle, initiates differentiation, and becomes a myelin-forming oligodendrocyte that wraps axons. Here we discuss recent advances towards understanding the epigenetic control of oligodendrocyte development that integrates environmental stimuli. We suggest that OPCs are directly responsive to extrinsic signals due to predominantly euchromatic nuclei, while the heterochromatic nuclei render differentiating and myelinating cells less susceptible to signals modulating the epigenome.
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Affiliation(s)
- Jia Liu
- Department of Neuroscience, Friedman Brain Institute and Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, United States.
| | - Sarah Moyon
- Department of Neuroscience, Friedman Brain Institute and Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, United States
| | - Marylens Hernandez
- Department of Neuroscience, Friedman Brain Institute and Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, United States
| | - Patrizia Casaccia
- Department of Neuroscience, Friedman Brain Institute and Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, United States; Department of Genetics and Genomics, Friedman Brain Institute and Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, United States
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45
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Thakurela S, Garding A, Jung RB, Müller C, Goebbels S, White R, Werner HB, Tiwari VK. The transcriptome of mouse central nervous system myelin. Sci Rep 2016; 6:25828. [PMID: 27173133 PMCID: PMC4865983 DOI: 10.1038/srep25828] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/21/2016] [Indexed: 01/03/2023] Open
Abstract
Rapid nerve conduction in the CNS is facilitated by insulation of axons with myelin, a specialized oligodendroglial compartment distant from the cell body. Myelin is turned over and adapted throughout life; however, the molecular and cellular basis of myelin dynamics remains elusive. Here we performed a comprehensive transcriptome analysis (RNA-seq) of myelin biochemically purified from mouse brains at various ages and find a surprisingly large pool of transcripts enriched in myelin. Further computational analysis showed that the myelin transcriptome is closely related to the myelin proteome but clearly distinct from the transcriptomes of oligodendrocytes and brain tissues, suggesting a highly selective incorporation of mRNAs into the myelin compartment. The mRNA-pool in myelin displays maturation-dependent dynamic changes of composition, abundance, and functional associations; however ageing-dependent changes after 6 months were minor. We suggest that this transcript pool enables myelin turnover and the local adaptation of individual pre-existing myelin sheaths.
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Affiliation(s)
| | - Angela Garding
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Ramona B. Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Christina Müller
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, 55128 Mainz, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Robin White
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, 55128 Mainz, Germany
| | - Hauke B. Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
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46
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Du F, Nguyen MVC, Karten A, Felice CA, Mandel G, Ballas N. Acute and crucial requirement for MeCP2 function upon transition from early to late adult stages of brain maturation. Hum Mol Genet 2016; 25:1690-702. [PMID: 26908602 DOI: 10.1093/hmg/ddw038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 02/05/2016] [Indexed: 12/11/2022] Open
Abstract
Germline mutations in the X-linked gene, methyl-CpG-binding protein 2 (MECP2), underlie most cases of Rett syndrome (RTT), an autism spectrum disorder affecting approximately one in 10 000 female live births. The disease is characterized in affected girls by a latent appearance of symptoms between 12 and 18 months of age while boys usually die before the age of two. The nature of the latency is not known, but RTT-like phenotypes are recapitulated in mouse models, even when MeCP2 is removed at different postnatal stages, including juvenile and adolescent stages. Unexpectedly, here, we show that within a very brief developmental window, between 10 (adolescent) and 15 (adult) weeks after birth, symptom initiation and progression upon removal of MeCP2 in male mice transitions from 3 to 4 months to only several days, followed by lethality. We further show that this accelerated development of RTT phenotype and lethality occur at the transition to adult stage (15 weeks of age) and persists thereafter. Importantly, within this abbreviated time frame of days, the brain acquires dramatic anatomical, cellular and molecular abnormalities, typical of classical RTT. This study reveals a new postnatal developmental stage, which coincides with full-brain maturation, where the structure/function of the brain is extremely sensitive to levels of MeCP2 and loss of MeCP2 leads to precipitous collapse of the neuronal networks and incompatibility with life within days.
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Affiliation(s)
- Fang Du
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA and
| | - Minh Vu Chuong Nguyen
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA and
| | - Ariel Karten
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA and
| | - Christy A Felice
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA and
| | - Gail Mandel
- Vollum Institute, Howard Hughes Medical Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Nurit Ballas
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA and
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47
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Vacca M, Tripathi KP, Speranza L, Aiese Cigliano R, Scalabrì F, Marracino F, Madonna M, Sanseverino W, Perrone-Capano C, Guarracino MR, D'Esposito M. Effects of Mecp2 loss of function in embryonic cortical neurons: a bioinformatics strategy to sort out non-neuronal cells variability from transcriptome profiling. BMC Bioinformatics 2016; 17 Suppl 2:14. [PMID: 26821710 PMCID: PMC4959389 DOI: 10.1186/s12859-015-0859-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Mecp2 null mice model Rett syndrome (RTT) a human neurological disorder affecting females after apparent normal pre- and peri-natal developmental periods. Neuroanatomical studies in cerebral cortex of RTT mouse models revealed delayed maturation of neuronal morphology and autonomous as well as non-cell autonomous reduction in dendritic complexity of postnatal cortical neurons. However, both morphometric parameters and high-resolution expression profile of cortical neurons at embryonic developmental stage have not yet been studied. Here we address these topics by using embryonic neuronal primary cultures from Mecp2 loss of function mouse model. Results We show that embryonic primary cortical neurons of Mecp2 null mice display reduced neurite complexity possibly reflecting transcriptional changes. We used RNA-sequencing coupled with a bioinformatics comparative approach to identify and remove the contribution of variable and hard to quantify non-neuronal brain cells present in our in vitro cell cultures. Conclusions Our results support the need to investigate both Mecp2 morphological as well as molecular effect in neurons since prenatal developmental stage, long time before onset of Rett symptoms. Electronic supplementary material The online version of this article (doi:10.1186/s12859-015-0859-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marcella Vacca
- Institute of Genetics and Biophysics "A. Buzzati Traverso", National Research Council (CNR)-80131, Naples, Italy.
| | - Kumar Parijat Tripathi
- Laboratory for Genomics, Transcriptomics and Proteomics (LAB-GTP), High Performance Computing and Networking Institute (ICAR), National Research Council (CNR)-80131, Naples, Italy.
| | - Luisa Speranza
- Institute of Genetics and Biophysics "A. Buzzati Traverso", National Research Council (CNR)-80131, Naples, Italy.
| | | | | | | | | | - Walter Sanseverino
- Sequentia Biotech SL, Calle Comte D'Urgell, 240 08036, Barcelona, Spain.
| | - Carla Perrone-Capano
- Institute of Genetics and Biophysics "A. Buzzati Traverso", National Research Council (CNR)-80131, Naples, Italy. .,Department of Pharmacy, University of Naples Federico II, Naples, Italy.
| | - Mario Rosario Guarracino
- Laboratory for Genomics, Transcriptomics and Proteomics (LAB-GTP), High Performance Computing and Networking Institute (ICAR), National Research Council (CNR)-80131, Naples, Italy.
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics "A. Buzzati Traverso", National Research Council (CNR)-80131, Naples, Italy. .,IRCCS Neuromed, via dell'Elettronica, Pozzilli (Is), Italy.
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48
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McGowan H, Pang ZP. Regulatory functions and pathological relevance of the MECP2 3'UTR in the central nervous system. CELL REGENERATION 2015; 4:9. [PMID: 26516454 PMCID: PMC4625459 DOI: 10.1186/s13619-015-0023-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 09/18/2015] [Indexed: 11/10/2022]
Abstract
Methyl-CpG-binding protein 2 (MeCP2), encoded by the gene MECP2, is a transcriptional regulator and chromatin-remodeling protein, which is ubiquitously expressed and plays an essential role in the development and maintenance of the central nervous system (CNS). Highly enriched in post-migratory neurons, MeCP2 is needed for neuronal maturation, including dendritic arborization and the development of synapses. Loss-of-function mutations in MECP2 cause Rett syndrome (RTT), a debilitating neurodevelopmental disorder characterized by a phase of normal development, followed by the progressive loss of milestones and cognitive disability. While a great deal has been discovered about the structure, function, and regulation of MeCP2 in the time since its discovery as the genetic cause of RTT, including its involvement in a number of RTT-related syndromes that have come to be known as MeCP2-spectrum disorders, much about this multifunctional protein remains enigmatic. One unequivocal fact that has become apparent is the importance of maintaining MeCP2 protein levels within a narrow range, the limits of which may depend upon the cell type and developmental time point. As such, MeCP2 is amenable to complex, multifactorial regulation. Here, we summarize the role of the MECP2 3' untranslated region (UTR) in the regulation of MeCP2 protein levels and how mutations in this region contribute to autism and other non-RTT neuropsychiatric disorders.
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Affiliation(s)
- Heather McGowan
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University Robert Wood Johnson Medical School, 89 French Street, Room 3277, New Brunswick, NJ 08901 USA
| | - Zhiping P Pang
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University Robert Wood Johnson Medical School, 89 French Street, Room 3277, New Brunswick, NJ 08901 USA
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Cuddapah VA, Sinifunanya EN, Percy AK, Olsen ML. MeCP2 in the regulation of neural activity: Rett syndrome pathophysiological perspectives. Degener Neurol Neuromuscul Dis 2015; 5:103-116. [PMID: 32669918 PMCID: PMC7337177 DOI: 10.2147/dnnd.s61269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 04/23/2015] [Indexed: 11/23/2022] Open
Abstract
Rett syndrome (RTT), an X-linked neurodevelopment disorder, occurs in approximately one out of 10,000 females. Individuals afflicted by RTT display a constellation of signs and symptoms, affecting nearly every organ system. Most striking are the neurological manifestations, including regression of language and motor skills, increased seizure activity, autonomic dysfunction, and aberrant regulation of breathing patterns. The majority of girls with RTT have mutations in the gene encoding for methyl-CpG binding protein 2 (MeCP2). Since the discovery of this genetic cause of RTT in 1999, there has been an accelerated pace of research seeking to understand the role of MeCP2 in the brain in the hope of developing a disease-modifying therapy for RTT. In this study, we review the clinical features of RTT and then explore the latest mechanistic studies in order to explain how a mutation in MeCP2 leads to these unique features. We cover in detail studies examining the role of MeCP2 in neuronal physiology, as well as recent evidence that implicates a key role for glia in the pathogenesis of RTT. In the past 20 years, these basic and clinical studies have yielded an extraordinary understanding of RTT; as such, we end this narrative review considering the translation of these studies into clinical trials for the treatment of RTT.
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Affiliation(s)
| | | | - Alan K Percy
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
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50
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Lee DY. Roles of mTOR Signaling in Brain Development. Exp Neurobiol 2015; 24:177-85. [PMID: 26412966 PMCID: PMC4580744 DOI: 10.5607/en.2015.24.3.177] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/02/2015] [Accepted: 09/02/2015] [Indexed: 12/18/2022] Open
Abstract
mTOR is a serine/threonine kinase composed of multiple protein components. Intracellular signaling of mTOR complexes is involved in many of physiological functions including cell survival, proliferation and differentiation through the regulation of protein synthesis in multiple cell types. During brain development, mTOR-mediated signaling pathway plays a crucial role in the process of neuronal and glial differentiation and the maintenance of the stemness of neural stem cells. The abnormalities in the activity of mTOR and its downstream signaling molecules in neural stem cells result in severe defects of brain developmental processes causing a significant number of brain disorders, such as pediatric brain tumors, autism, seizure, learning disability and mental retardation. Understanding the implication of mTOR activity in neural stem cells would be able to provide an important clue in the development of future brain developmental disorder therapies.
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Affiliation(s)
- Da Yong Lee
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea
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