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Dennys CN, Vermudez SAD, Deacon RJM, Sierra-Delgado JA, Rich K, Zhang X, Buch A, Weiss K, Moxley Y, Rajpal H, Espinoza FD, Powers S, Ávila AS, Gogliotti RG, Cogram P, Niswender CM, Meyer KC. MeCP2 gene therapy ameliorates disease phenotype in mouse model for Pitt Hopkins syndrome. Neurotherapeutics 2024:e00376. [PMID: 38876822 DOI: 10.1016/j.neurot.2024.e00376] [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: 10/17/2023] [Revised: 05/07/2024] [Accepted: 05/14/2024] [Indexed: 06/16/2024] Open
Abstract
The neurodevelopmental disorder Pitt Hopkins syndrome (PTHS) causes clinical symptoms similar to Rett syndrome (RTT) patients. However, RTT is caused by MECP2 mutations whereas mutations in the TCF4 gene lead to PTHS. The mechanistic commonalities underling these two disorders are unknown, but their shared symptomology suggest that convergent pathway-level disruption likely exists. We reprogrammed patient skin derived fibroblasts into induced neuronal progenitor cells. Interestingly, we discovered that MeCP2 levels were decreased in PTHS patient iNPCs relative to healthy controls and that both iNPCs and iAstrocytes displayed defects in function and differentiation in a mutation-specific manner. When Tcf4+/- mice were genetically crossed with mice overexpressing MeCP2, molecular and phenotypic defects were significantly ameliorated, underlining and important role of MeCP2 in PTHS pathology. Importantly, post-natal intracerebroventricular gene replacement therapy with adeno-associated viral vector serotype 9 (AAV9)-expressing MeCP2 (AAV9.P546.MeCP2) significantly improved iNPC and iAstrocyte function and effectively ameliorated histological and behavioral defects in Tcf4+/- mice. Combined, our data suggest a previously unknown role of MeCP2 in PTHS pathology and common pathways that might be affected in multiple neurodevelopmental disorders. Our work highlights potential novel therapeutic targets for PTHS, including upregulation of MeCP2 expression or its downstream targets or, potentially, MeCP2-based gene therapy.
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Affiliation(s)
- Cassandra N Dennys
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Sheryl Anne D Vermudez
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Robert J M Deacon
- Department of Genetics, Institute of Ecology and Biodiversity, Faculty of Science, University of Chile, Chile
| | - J Andrea Sierra-Delgado
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Kelly Rich
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Xiaojin Zhang
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Aditi Buch
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Kelly Weiss
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Yuta Moxley
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Hemangi Rajpal
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Francisca D Espinoza
- Faculty of Medicine, Universidad Católica de la Santísima Concepción, Concepción, 4090541, Chile
| | - Samantha Powers
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Ariel S Ávila
- Faculty of Medicine, Universidad Católica de la Santísima Concepción, Concepción, 4090541, Chile
| | - Rocco G Gogliotti
- Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, IL 60153, USA
| | - Patricia Cogram
- Department of Genetics, Institute of Ecology and Biodiversity, Faculty of Science, University of Chile, Chile
| | - Colleen M Niswender
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kathrin C Meyer
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University Medical Center, Columbus, OH, USA; Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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2
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Odabasi Y, Yanasik S, Saglam-Metiner P, Kaymaz Y, Yesil-Celiktas O. Comprehensive Transcriptomic Investigation of Rett Syndrome Reveals Increasing Complexity Trends from Induced Pluripotent Stem Cells to Neurons with Implications for Enriched Pathways. ACS OMEGA 2023; 8:44148-44162. [PMID: 38027357 PMCID: PMC10666228 DOI: 10.1021/acsomega.3c06448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/19/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023]
Abstract
Rett syndrome (RTT) is a rare genetic neurodevelopmental disorder that has no cure apart from symptomatic treatments. While intense research efforts are required to fulfill this unmet need, the fundamental challenge is to obtain sufficient patient data. In this study, we used human transcriptomic data of four different sample types from RTT patients including induced pluripotent stem cells, differentiated neural progenitor cells, differentiated neurons, and postmortem brain tissues with an increasing in vivo-like complexity to unveil specific trends in gene expressions across the samples. Based on DEG analysis, we identified F8A3, CNTN6, RPE65, and COL19A1 to have differential expression levels in three sample types and also observed previously reported genes such as MECP2, FOXG1, CACNA1G, SATB2, GABBR2, MEF2C, KCNJ10, and CUX2 in our study. Considering the significantly enriched pathways for each sample type, we observed a consistent increase in numbers from iPSCs to NEUs where MECP2 displayed profound effects. We also validated our GSEA results by using single-cell RNA-seq data. In WGCNA, we elicited a connection among MECP2, TNRC6A, and HOXA5. Our findings highlight the utility of transcriptomic analyses to determine genes that might lead to therapeutic strategies.
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Affiliation(s)
- Yusuf
Caglar Odabasi
- Department of Bioengineering,
Faculty of Engineering, Ege University, Izmir 35100, Turkey
| | - Sena Yanasik
- Department of Bioengineering,
Faculty of Engineering, Ege University, Izmir 35100, Turkey
| | - Pelin Saglam-Metiner
- Department of Bioengineering,
Faculty of Engineering, Ege University, Izmir 35100, Turkey
| | - Yasin Kaymaz
- Department of Bioengineering,
Faculty of Engineering, Ege University, Izmir 35100, Turkey
| | - Ozlem Yesil-Celiktas
- Department of Bioengineering,
Faculty of Engineering, Ege University, Izmir 35100, Turkey
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3
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Rabeling A, Goolam M. Cerebral organoids as an in vitro model to study autism spectrum disorders. Gene Ther 2023; 30:659-669. [PMID: 35790793 DOI: 10.1038/s41434-022-00356-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 06/01/2022] [Accepted: 06/23/2022] [Indexed: 11/09/2022]
Abstract
Autism spectrum disorders (ASDs) are a set of disorders characterised by social and communication deficits caused by numerous genetic lesions affecting brain development. Progress in ASD research has been hampered by the lack of appropriate models, as both 2D cell culture as well as animal models cannot fully recapitulate the developing human brain or the pathogenesis of ASD. Recently, cerebral organoids have been developed to provide a more accurate, 3D in vitro model of human brain development. Cerebral organoids have been shown to recapitulate the foetal brain gene expression profile, transcriptome, epigenome, as well as disease dynamics of both idiopathic and syndromic ASDs. They are thus an excellent tool to investigate development of foetal stage ASDs, as well as interventions that can reverse or rescue the altered phenotypes observed. In this review, we discuss the development of cerebral organoids, their recent applications in the study of both syndromic and idiopathic ASDs, their use as an ASD drug development platform, as well as limitations of their use in ASD research.
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Affiliation(s)
- Alexa Rabeling
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, 7925, South Africa
| | - Mubeen Goolam
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, 7925, South Africa.
- UCT Neuroscience Institute, Cape Town, South Africa.
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4
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Carli S, Chaabane L, De Rocco G, Albizzati E, Sormonta I, Calligaro S, Bonizzi P, Frasca A, Landsberger N. A comprehensive longitudinal study of magnetic resonance imaging identifies novel features of the Mecp2 deficient mouse brain. Neurobiol Dis 2023; 180:106083. [PMID: 36931532 DOI: 10.1016/j.nbd.2023.106083] [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: 12/13/2022] [Revised: 02/17/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Rett syndrome (RTT) is a X-linked neurodevelopmental disorder which represents the leading cause of severe incurable intellectual disability in females worldwide. The vast majority of RTT cases are caused by mutations in the X-linked MECP2 gene, and preclinical studies on RTT largely benefit from the use of mouse models of Mecp2, which present a broad spectrum of symptoms phenocopying those manifested by RTT patients. Neurons represent the core targets of the pathology; however, neuroanatomical abnormalities that regionally characterize the Mecp2 deficient mammalian brain remain ill-defined. Neuroimaging techniques, such as MRI and MRS, represent a key approach for assessing in vivo anatomic and metabolic changes in brain. Being non-invasive, these analyses also permit to investigate how the disease progresses over time through longitudinal studies. To foster the biological comprehension of RTT and identify useful biomarkers, we have performed a thorough in vivo longitudinal study of MRI and MRS in Mecp2 deficient mouse brains. Analyses were performed on both genders of two different mouse models of RTT, using an automatic atlas-based segmentation tool that permitted to obtain a detailed and unbiased description of the whole RTT mouse brain. We found that the most robust alteration of the RTT brain consists in an overall reduction of the brain volume. Accordingly, Mecp2 deficiency generally delays brain growth, eventually leading, in heterozygous older animals, to stagnation and/or contraction. Most but not all brain regions participate in the observed deficiency in brain size; similarly, the volumetric defect progresses diversely in different brain areas also depending on the specific Mecp2 genetic lesion and gender. Interestingly, in some regions volumetric defects anticipate overt symptoms, possibly revealing where the pathology originates and providing a useful biomarker for assessing drug efficacy in pre-clinical studies.
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Affiliation(s)
- Sara Carli
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan I-20132, Italy.
| | - Linda Chaabane
- Institute of Experimental Neurology (INSPE) and Experimental Imaging Center (CIS), IRCCS San Raffaele Scientific Institute, Milan I-20132, Italy.
| | - Giuseppina De Rocco
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan I-20132, Italy; Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan) I-20090, Italy.
| | - Elena Albizzati
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan) I-20090, Italy.
| | - Irene Sormonta
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan I-20132, Italy.
| | - Stefano Calligaro
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan I-20132, Italy.
| | - Pietro Bonizzi
- Department of Advanced Computing Sciences, Maastricht University, Maastricht, the Netherlands.
| | - Angelisa Frasca
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan) I-20090, Italy.
| | - Nicoletta Landsberger
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan I-20132, Italy; Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan) I-20090, Italy.
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5
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Zanotti S, Decaesteker B, Vanhauwaert S, De Wilde B, De Vos WH, Speleman F. Cellular senescence in neuroblastoma. Br J Cancer 2022; 126:1529-1538. [PMID: 35197583 PMCID: PMC9130206 DOI: 10.1038/s41416-022-01755-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/14/2022] [Accepted: 02/10/2022] [Indexed: 12/14/2022] Open
Abstract
Neuroblastoma is a tumour that arises from the sympathoadrenal lineage occurring predominantly in children younger than five years. About half of the patients are diagnosed with high-risk tumours and undergo intensive multi-modal therapy. The success rate of current treatments for high-risk neuroblastoma is disappointingly low and survivors suffer from multiple therapy-related long-term side effects. Most chemotherapeutics drive cancer cells towards cell death or senescence. Senescence has long been considered to represent a terminal non-proliferative state and therefore an effective barrier against tumorigenesis. This dogma, however, has been challenged by recent observations that infer a much more dynamic and reversible nature for this process, which may have implications for the efficacy of therapy-induced senescence-oriented treatment strategies. Neuroblastoma cells in a dormant, senescent-like state may escape therapy, whilst their senescence-associated secretome may promote inflammation and invasiveness, potentially fostering relapse. Conversely, due to its distinct molecular identity, senescence may also represent an opportunity for the development of novel (combination) therapies. However, the limited knowledge on the molecular dynamics and diversity of senescence signatures demands appropriate models to study this process in detail. This review summarises the molecular knowledge about cellular senescence in neuroblastoma and investigates current and future options towards therapeutic exploration.
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Affiliation(s)
- Sofia Zanotti
- grid.5284.b0000 0001 0790 3681Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, Antwerp, 2610 Belgium ,grid.5342.00000 0001 2069 7798Department of Biomolecular Medicine, Ghent University, Corneel Heymanslaan 10, Ghent, 9000 Belgium ,grid.510942.bCancer Research Institute Ghent (CRIG), Ghent, 9000 Belgium
| | - Bieke Decaesteker
- grid.5342.00000 0001 2069 7798Department of Biomolecular Medicine, Ghent University, Corneel Heymanslaan 10, Ghent, 9000 Belgium ,grid.510942.bCancer Research Institute Ghent (CRIG), Ghent, 9000 Belgium
| | - Suzanne Vanhauwaert
- grid.5342.00000 0001 2069 7798Department of Biomolecular Medicine, Ghent University, Corneel Heymanslaan 10, Ghent, 9000 Belgium ,grid.510942.bCancer Research Institute Ghent (CRIG), Ghent, 9000 Belgium
| | - Bram De Wilde
- grid.5342.00000 0001 2069 7798Department of Biomolecular Medicine, Ghent University, Corneel Heymanslaan 10, Ghent, 9000 Belgium ,grid.5342.00000 0001 2069 7798Department of Internal Medicine and Pediatrics, Ghent University, Corneel Heymanslaan 10, Ghent, 9000 Belgium ,grid.410566.00000 0004 0626 3303Department of Pediatric Hematology Oncology and Stem Cell Transplantation, Ghent University Hospital, Ghent, 9000 Belgium
| | - Winnok H. De Vos
- grid.5284.b0000 0001 0790 3681Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, Antwerp, 2610 Belgium
| | - Frank Speleman
- Department of Biomolecular Medicine, Ghent University, Corneel Heymanslaan 10, Ghent, 9000, Belgium. .,Cancer Research Institute Ghent (CRIG), Ghent, 9000, Belgium.
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6
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FAZELI Z, GHADERIAN SMH, NAJMABADI H, OMRANI MD. Understanding the Molecular Basis of Fragile X Syndrome Using Differentiated Mesenchymal Stem Cells. IRANIAN JOURNAL OF CHILD NEUROLOGY 2022; 16:85-95. [PMID: 35222660 PMCID: PMC8753000 DOI: 10.22037/ijcn.v15i4.22070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 02/21/2021] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Fragile X syndrome (FXS) has been known as the most common cause of inherited intellectual disability and autism. This disease results from the loss of fragile X mental retardation protein expression due to the expansion of CGG repeats located on the 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene. MATERIALS & METHODS In the present study, the peripheral blood-mesenchymal stem cells (PB-MSCs) of two female full mutation carriers were differentiated into neuronal cells by the suppression of bone morphogenesis pathway signaling. Then, the expression of genes adjacent to CGG repeats expansion, including SLIT and NTRK-like protein 2 (SLITRK2), SLIT and NTRK-like protein 4 (SLITRK4), methyl CpG binding protein 2 (MECP2), and gamma-aminobutyric acid receptor subunit alpha-3 (GABRA3), were evaluated in these cells using SYBR Green real-time polymerase chain reaction. RESULTS The obtained results indicated that the expression of SLITRK2 and SLITRK4 were upregulated and downregulated in the neuron-like cells differentiated from the PB-MSCs of females with FMR1 full mutation, compared to that of the normal females, respectively. Furthermore, the expression of MECP2 and GABRA3 genes were observed to be related to the phenotypic differences observed in the female FMR1 full mutation carriers. CONCLUSION The observed association of expression of genes located upstream of the FMR1 gene with phenotypic differences in the female carriers could increase the understanding of novel therapeutic targets for patients with mild symptoms of FXS and the patients affected by other FMR1-related disorders.
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Affiliation(s)
- Zahra FAZELI
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Hossein NAJMABADI
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Mir Davood OMRANI
- Urogenital Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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7
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Samarasinghe RA, Miranda OA, Buth JE, Mitchell S, Ferando I, Watanabe M, Allison TF, Kurdian A, Fotion NN, Gandal MJ, Golshani P, Plath K, Lowry WE, Parent JM, Mody I, Novitch BG. Identification of neural oscillations and epileptiform changes in human brain organoids. Nat Neurosci 2021; 24:1488-1500. [PMID: 34426698 PMCID: PMC9070733 DOI: 10.1038/s41593-021-00906-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 07/08/2021] [Indexed: 02/06/2023]
Abstract
Brain organoids represent a powerful tool for studying human neurological diseases, particularly those that affect brain growth and structure. However, many diseases manifest with clear evidence of physiological and network abnormality in the absence of anatomical changes, raising the question of whether organoids possess sufficient neural network complexity to model these conditions. Here, we explore the network-level functions of brain organoids using calcium sensor imaging and extracellular recording approaches that together reveal the existence of complex network dynamics reminiscent of intact brain preparations. We demonstrate highly abnormal and epileptiform-like activity in organoids derived from induced pluripotent stem cells from individuals with Rett syndrome, accompanied by transcriptomic differences revealed by single-cell analyses. We also rescue key physiological activities with an unconventional neuroregulatory drug, pifithrin-α. Together, these findings provide an essential foundation for the utilization of brain organoids to study intact and disordered human brain network formation and illustrate their utility in therapeutic discovery.
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Affiliation(s)
- Ranmal A. Samarasinghe
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Osvaldo A. Miranda
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Jessie E. Buth
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Simon Mitchell
- Institute for Quantitative and Computational Biosciences, Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, USA,Brighton and Sussex Medical School, Falmer, United Kingdom
| | - Isabella Ferando
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Momoko Watanabe
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Thomas F. Allison
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Arinnae Kurdian
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,California State University, Northridge, Northridge, California USA
| | - Namie N. Fotion
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Michael J. Gandal
- Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, California, USA,West Los Angeles VA Medical Center, Los Angeles, California, USA
| | - Kathrin Plath
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - William E. Lowry
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA
| | - Jack M. Parent
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA,Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA,Ann Arbor VA Healthcare System, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Istvan Mody
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Bennett G. Novitch
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,Corresponding author. (B.G.N.)
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8
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Analysis of Astroglial Secretomic Profile in the Mecp2-Deficient Male Mouse Model of Rett Syndrome. Int J Mol Sci 2021; 22:ijms22094316. [PMID: 33919253 PMCID: PMC8122273 DOI: 10.3390/ijms22094316] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 02/08/2023] Open
Abstract
Mutations in the X-linked MECP2 gene are responsible for Rett syndrome (RTT), a severe neurological disorder. MECP2 is a transcriptional modulator that finely regulates the expression of many genes, specifically in the central nervous system. Several studies have functionally linked the loss of MECP2 in astrocytes to the appearance and progression of the RTT phenotype in a non-cell autonomous manner and mechanisms are still unknown. Here, we used primary astroglial cells from Mecp2-deficient (KO) pups to identify deregulated secreted proteins. Using a differential quantitative proteomic analysis, twenty-nine proteins have been identified and four were confirmed by Western blotting with new samples as significantly deregulated. To further verify the functional relevance of these proteins in RTT, we tested their effects on the dendritic morphology of primary cortical neurons from Mecp2 KO mice that are known to display shorter dendritic processes. Using Sholl analysis, we found that incubation with Lcn2 or Lgals3 for 48 h was able to significantly increase the dendritic arborization of Mecp2 KO neurons. To our knowledge, this study, through secretomic analysis, is the first to identify astroglial secreted proteins involved in the neuronal RTT phenotype in vitro, which could open new therapeutic avenues for the treatment of Rett syndrome.
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9
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Abstract
Despite decades of research on Alzheimer disease, understanding the complexity of the genetic and molecular interactions involved in its pathogenesis remains far from our grasp. Methyl-CpG Binding Protein 2 (MeCP2) is an important epigenetic regulator enriched in the brain, and recent findings have implicated MeCP2 as a crucial player in Alzheimer disease. Here, we provide comprehensive insights into the pathophysiological roles of MeCP2 in Alzheimer disease. In particular, we focus on how the alteration of MeCP2 expression can impact Alzheimer disease through risk genes, amyloid-β and tau pathology, cell death and neurodegeneration, and cellular senescence. We suggest that Alzheimer disease can be adversely affected by upregulated MeCP2-dependent repression of risk genes (MEF2C, ADAM10, and PM20D1), increased tau accumulation, and neurodegeneration through neuronal cell death (excitotoxicity and apoptosis). In addition, we propose that the progression of Alzheimer disease could be caused by reduced MeCP2-mediated enhancement of astrocytic and microglial senescence and consequent glial SASP (senescence-associated secretory phenotype)-dependent neuroinflammation. We surmise that any imbalance in MeCP2 function would accelerate or cause Alzheimer disease pathogenesis, implying that MeCP2 may be a potential drug target for the treatment and prevention of Alzheimer disease.
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10
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Gulmez Karaca K, Brito DV, Oliveira AM. MeCP2: A Critical Regulator of Chromatin in Neurodevelopment and Adult Brain Function. Int J Mol Sci 2019; 20:ijms20184577. [PMID: 31527487 PMCID: PMC6769791 DOI: 10.3390/ijms20184577] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 01/08/2023] Open
Abstract
Methyl CpG binding protein 2 (MeCP2) was first identified as a nuclear protein with a transcriptional repressor role that recognizes DNA methylation marks. MeCP2 has a well-established function in neurodevelopment, as evidenced by the severe neurological impairments characteristic of the Rett syndrome (RTT) pathology and the MeCP2 duplication syndrome (MDS), caused by loss or gain of MeCP2 function, respectively. Research aimed at the underlying pathophysiological mechanisms of RTT and MDS has significantly advanced our understanding of MeCP2 functions in the nervous system. It has revealed, however, that MeCP2 has more varied and complex roles than previously thought. Here we review recent insights into the functions of MeCP2 in neurodevelopment and the less explored requirement for MeCP2 in adult brain function. We focus on the emerging view that MeCP2 is a global chromatin organizer. Finally, we discuss how the individual functions of MeCP2 in neurodevelopment and adulthood are linked to its role as a chromatin regulator.
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Affiliation(s)
- Kubra Gulmez Karaca
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany; (K.G.K.)
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 EN Nijmegen, The Netherlands
| | - David V.C. Brito
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany; (K.G.K.)
| | - Ana M.M. Oliveira
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany; (K.G.K.)
- Correspondence: ; Tel.: +49-(0)6221-5416510
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11
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Keidar L, Gerlitz G, Kshirsagar A, Tsoory M, Olender T, Wang X, Yang Y, Chen YS, Yang YG, Voineagu I, Reiner O. Interplay of LIS1 and MeCP2: Interactions and Implications With the Neurodevelopmental Disorders Lissencephaly and Rett Syndrome. Front Cell Neurosci 2019; 13:370. [PMID: 31474834 PMCID: PMC6703185 DOI: 10.3389/fncel.2019.00370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 07/30/2019] [Indexed: 12/30/2022] Open
Abstract
LIS1 is the main causative gene for lissencephaly, while MeCP2 is the main causative gene for Rett syndrome, both of which are neurodevelopmental diseases. Here we report nuclear functions for LIS1 and identify previously unrecognized physical and genetic interactions between the products of these two genes in the cell nucleus, that has implications on MeCP2 organization, neuronal gene expression and mouse behavior. Reduced LIS1 levels affect the association of MeCP2 with chromatin. Transcriptome analysis of primary cortical neurons derived from wild type, Lis1±, MeCP2−/y, or double mutants mice revealed a large overlap in the differentially expressed (DE) genes between the various mutants. Overall, our findings provide insights on molecular mechanisms involved in the neurodevelopmental disorders lissencephaly and Rett syndrome caused by dysfunction of LIS1 and MeCP2, respectively.
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Affiliation(s)
- Liraz Keidar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gabi Gerlitz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Aditya Kshirsagar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Tsoory
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Xing Wang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Ying Yang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Yu-Sheng Chen
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Yun-Gui Yang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Irina Voineagu
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Orly Reiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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12
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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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13
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Squillaro T, Alessio N, Capasso S, Di Bernardo G, Melone MAB, Peluso G, Galderisi U. Senescence Phenomena and Metabolic Alteration in Mesenchymal Stromal Cells from a Mouse Model of Rett Syndrome. Int J Mol Sci 2019; 20:ijms20102508. [PMID: 31117273 PMCID: PMC6567034 DOI: 10.3390/ijms20102508] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/17/2019] [Accepted: 05/19/2019] [Indexed: 12/17/2022] Open
Abstract
Chromatin modifiers play a crucial role in maintaining cell identity through modulation of gene expression patterns. Their deregulation can have profound effects on cell fate and functions. Among epigenetic regulators, the MECP2 protein is particularly attractive. Mutations in the Mecp2 gene are responsible for more than 90% of cases of Rett syndrome (RTT), a progressive neurodevelopmental disorder. As a chromatin modulator, MECP2 can have a key role in the government of stem cell biology. Previously, we showed that deregulated MECP2 expression triggers senescence in mesenchymal stromal cells (MSCs) from (RTT) patients. Over the last few decades, it has emerged that senescent cells show alterations in the metabolic state. Metabolic changes related to stem cell senescence are particularly detrimental, since they contribute to the exhaustion of stem cell compartments, which in turn determine the falling in tissue renewal and functionality. Herein, we dissect the role of impaired MECP2 function in triggering senescence along with other senescence-related aspects, such as metabolism, in MSCs from a mouse model of RTT. We found that MECP2 deficiencies lead to senescence and impaired mitochondrial energy production. Our results support the idea that an alteration in mitochondria metabolic functions could play an important role in the pathogenesis of RTT.
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Affiliation(s)
- Tiziana Squillaro
- Department of Advanced Medical and Surgical Sciences, Center for Rare Diseases and Inter University Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", via Sergio Pansini, 5, 80131 Naples, Italy.
| | - Nicola Alessio
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
| | - Stefania Capasso
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
| | - Giovanni Di Bernardo
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
| | - Mariarosa Anna Beatrice Melone
- Department of Advanced Medical and Surgical Sciences, Center for Rare Diseases and Inter University Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", via Sergio Pansini, 5, 80131 Naples, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, BioLife Building (015-00)1900 North 12th Street, Temple University, Philadelphia, PA 19122-6078, USA.
| | - Gianfranco Peluso
- USA Research Institute on Terrestrial Ecosystems, National Research Council, via Pietro Castellino, 111, 80131 Naples, Italy.
| | - Umberto Galderisi
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, BioLife Building (015-00)1900 North 12th Street, Temple University, Philadelphia, PA 19122-6078, USA.
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14
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Lack of MeCP2 leads to region-specific increase of doublecortin in the olfactory system. Brain Struct Funct 2019; 224:1647-1658. [PMID: 30923887 DOI: 10.1007/s00429-019-01860-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 03/09/2019] [Indexed: 10/27/2022]
Abstract
The protein doublecortin is mainly expressed in migrating neuroblasts and immature neurons. The X-linked gene MECP2, associated to several neurodevelopmental disorders such as Rett syndrome, encodes the protein methyl-CpG-binding protein 2 (MeCP2), a regulatory protein that has been implicated in neuronal maturation and refinement of olfactory circuits. Here, we explored doublecortin immunoreactivity in the brain of young adult female Mecp2-heterozygous and male Mecp2-null mice and their wild-type littermates. The distribution of doublecortin-immunoreactive somata in neurogenic brain regions was consistent with previous reports in rodents, and no qualitative differences were found between genotypes or sexes. Quantitatively, we found a significant increase in doublecortin cell density in the piriform cortex of Mecp2-null males as compared to WT littermates. A similar increase was seen in a newly identified population of doublecortin cells in the olfactory tubercle. In these olfactory structures, however, the percentage of doublecortin immature neurons that also expressed NeuN was not different between genotypes. By contrast, we found no significant differences between genotypes in doublecortin immunoreactivity in the olfactory bulbs. Nonetheless, in the periglomerular layer of Mecp2-null males, we observed a specific decrease of immature neurons co-expressing doublecortin and NeuN. Overall, no differences were evident between Mecp2-heterozygous and WT females. In addition, no differences could be detected between genotypes in the density of doublecortin-immunoreactive cells in the hippocampus or striatum of either males or females. Our results suggest that MeCP2 is involved in neuronal maturation in a region-dependent manner.
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15
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Squillaro T, Cimini A, Peluso G, Giordano A, Melone MAB. Nano-delivery systems for encapsulation of dietary polyphenols: An experimental approach for neurodegenerative diseases and brain tumors. Biochem Pharmacol 2018; 154:303-317. [PMID: 29803506 DOI: 10.1016/j.bcp.2018.05.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 05/23/2018] [Indexed: 02/06/2023]
Abstract
Neurodegenerative diseases (NDs) and brain tumors are severe, disabling, and incurable disorders that represent a critical problem regarding human suffering and the economic burden on the healthcare system. Because of the lack of effective therapies to treat NDs and brain tumors, the challenge for physicians is to discover new drugs to improve their patients' quality of life. In addition to risk factors such as genetics and environmental influences, increased cellular oxidative stress has been reported as one of the potential common etiologies in both disorders. Given their antioxidant and anti-inflammatory potential, dietary polyphenols are considered to be one of the most bioactive natural agents in chronic disease prevention and treatment. Despite the protective activity of polyphenols, their inefficient delivery systems and poor bioavailability strongly limit their use in medicine and functional food. A potential solution lies in polymeric nanoparticle-based polyphenol delivery systems that are able to enhance their absorption across the gastrointestinal tract, improve their bioavailability, and transport them to target organs. In the present manuscript, we provide an overview of the primary polyphenols used for ND and brain tumor prevention and treatment by focusing on recent findings, the principal factors limiting their application in clinical practice, and a promising delivery strategy to improve their bioavailability.
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Affiliation(s)
- T Squillaro
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - A Cimini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy; Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - G Peluso
- Institute of Agro-Environmental and Forest Biology, CNR, Naples, Italy
| | - A Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA; Department of Medicine, Surgery and Neuroscience University of Siena, Italy.
| | - M A B Melone
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases and InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Naples, Italy; Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.
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16
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Terracciano C, Pachatz C, Rastelli E, Pastore FS, Melone MAB, Massa R. Neurofibromatous neuropathy: An ultrastructural study. Ultrastruct Pathol 2018; 42:312-316. [PMID: 29583067 DOI: 10.1080/01913123.2018.1454562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Plexiform neurofibroma is pathognomonic of neurofibromatosis 1 (NF1). An NF1-associated peripheral neuropathy has been described in a small minority of NF1 patients but its histopathological features are poorly characterized. We report the case of a 46-year-old woman presenting with bilateral supraclavicular painful masses without other stigmata of NF1. MRI showed bilateral plexiform lesions extending from cervical roots to the elbows. Nerve conduction studies documented a sensory motor polyneuropathy. Morphometric analysis of sural nerve biopsy showed a preferential loss of large-caliber myelinated fibers with a g ratio of 0.515, and the presence of regeneration clusters. By electron microscopy, marked and diffuse endoneurial fibrosis with an altered relationship between Schwann cells (SC) and collagen fibrils was observed. Moreover both myelinating and non-myelinating SC were characterized by the presence of various cell degradation products. These changes suggest that, in neurofibromatous neuropathy, a widespread axonal atrophy and degeneration take place independently on the presence of tumoral infiltration, possibly due to an impairment in SC-axon cross talk. In this case, the coexistence of plexiform neurofibromas with a peripheral neuropathy strongly suggests a diagnosis of NF1 even without fulfillment of clinical criteria. We propose that in the presence of plexiform neurofibromas, electrophysiological studies should be performed also in asymptomatic patients, in order to detect the existence of a subclinical neuropathy.
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Affiliation(s)
- Chiara Terracciano
- a Neuromuscular Unit, Department of Systems Medicine , University of Rome Tor Vergata , Rome , Italy
| | - Christa Pachatz
- b Neurophysiopathology Unit, Department of Systems Medicine , University of Rome Tor Vergata , Rome , Italy
| | - Emanuele Rastelli
- a Neuromuscular Unit, Department of Systems Medicine , University of Rome Tor Vergata , Rome , Italy
| | | | - Mariarosa Anna Beatrice Melone
- d Department of Medicine, Surgery, Neurology, Metabolic and Aging Science, Reference Center for Neurological and Neuromuscular Rare Disease , University of Campania "Luigi Vanvitelli," , Naples , Italy
| | - Roberto Massa
- a Neuromuscular Unit, Department of Systems Medicine , University of Rome Tor Vergata , Rome , Italy
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17
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Alessio N, Riccitiello F, Squillaro T, Capasso S, Del Gaudio S, Di Bernardo G, Cipollaro M, Melone MAB, Peluso G, Galderisi U. Neural stem cells from a mouse model of Rett syndrome are prone to senescence, show reduced capacity to cope with genotoxic stress, and are impaired in the differentiation process. Exp Mol Med 2018; 50:1. [PMID: 29563495 PMCID: PMC6118406 DOI: 10.1038/s12276-017-0005-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 10/17/2017] [Accepted: 10/20/2017] [Indexed: 02/06/2023] Open
Abstract
Several aspects of stem cell life are governed by epigenetic variations, such as DNA methylation, histone modifications, and chromatin remodeling. Epigenetic events are also connected with the impairment of stem cell functions. For example, during senescence, there are significant changes in chromatin organization that alter transcription. The MECP2 protein can bind methylated cytosines and contribute to regulating gene expression at one of the highest hierarchical levels. Researchers are particularly interested in this protein, as up to 90% of Rett syndrome patients have an MECP2 gene mutation. Nevertheless, the role of MECP2 in this disease remains poorly understood. We used a mouse model of Rett syndrome to evaluate whether residual MECP2 activity in neural stem cells (NSCs) induced the senescence phenomena that could affect stem cell function. Our study clearly demonstrated that the reduced expression of MECP2 is connected with an increase in senescence, an impairment in proliferation capacity, and an accumulation of unrepaired DNA foci. Mecp2+/− NSCs did not cope with genotoxic stress in the same way as the control cells did. Indeed, after treatment with different DNA-damaging agents, the NSCs from mice with mutated Mecp2 accumulated more DNA damage foci (γ-H2AX+) and were more prone to cell death than the controls. Senescence in Mecp2+/− NSCs decreased the number of stem cells and progenitors and gave rise to a high percentage of cells that expressed neither stem/progenitor nor differentiation markers. These cells could be senescent and dysfunctional. In Rett syndrome, neural stem cells lose some of their “stem cell like” properties, impairing brain functions. Patients with this rare neurological condition, almost exclusively girls, show impaired movement and speech beginning at 6–18 months of age. Mutations in the MECP2 gene are known to be involved, but the specifics are poorly understood. Umberto Galderisi at Temple University in Philadelphia and co-workers in Italy used a mouse model to trace how MECP2 mutations affect neural stem cells. They found that the mutated cells lost key stem cell abilities, including the capacity to renew themselves by dividing, and the ability to differentiate, or turn into other cell types. The cells were also highly susceptible to DNA damage and unable to repair it. These results improve our understanding of Rett syndrome and may help develop new treatments.
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Affiliation(s)
- Nicola Alessio
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy
| | - Francesco Riccitiello
- Department of Neurosciences, Reproductive and Odontostomatologic Science, University "Federico II", Naples, Italy
| | - Tiziana Squillaro
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy.,Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, Division of Neurology and InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Stefania Capasso
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy
| | - Stefania Del Gaudio
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy
| | - Giovanni Di Bernardo
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy
| | - Marilena Cipollaro
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy
| | - Mariarosa A B Melone
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, Division of Neurology and InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Gianfranco Peluso
- Institute of Agro-Environmental Biology and Forestry (IBAF), CNR, Naples, Italy
| | - Umberto Galderisi
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", Naples, Italy. .,Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, Temple University, Philadelphia, PA, USA.
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18
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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: 29] [Impact Index Per Article: 4.1] [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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Della Bella E, Pagani S, Giavaresi G, Capelli I, Comai G, Donadei C, Cappuccilli M, La Manna G, Fini M. Uremic Serum Impairs Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stromal Cells. J Cell Physiol 2017; 232:2201-2209. [DOI: 10.1002/jcp.25732] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 12/13/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Elena Della Bella
- Laboratory of Preclinical and Surgical Studies; Rizzoli Orthopedic Institute; Bologna Italy
- Department of Experimental, Diagnostic and Specialty Medicine; University of Bologna; Bologna Italy
| | - Stefania Pagani
- Laboratory of Preclinical and Surgical Studies; Rizzoli Orthopedic Institute; Bologna Italy
- Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies; Department Rizzoli RIT; Bologna Italy
| | - Gianluca Giavaresi
- Laboratory of Preclinical and Surgical Studies; Rizzoli Orthopedic Institute; Bologna Italy
- Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies; Department Rizzoli RIT; Bologna Italy
| | - Irene Capelli
- Nephrology Dialysis and Transplantation Unit, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola Hospital; University of Bologna; Bologna Italy
| | - Giorgia Comai
- Nephrology Dialysis and Transplantation Unit, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola Hospital; University of Bologna; Bologna Italy
| | - Chiara Donadei
- Nephrology Dialysis and Transplantation Unit, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola Hospital; University of Bologna; Bologna Italy
| | - Maria Cappuccilli
- Nephrology Dialysis and Transplantation Unit, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola Hospital; University of Bologna; Bologna Italy
| | - Gaetano La Manna
- Nephrology Dialysis and Transplantation Unit, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola Hospital; University of Bologna; Bologna Italy
| | - Milena Fini
- Laboratory of Preclinical and Surgical Studies; Rizzoli Orthopedic Institute; Bologna Italy
- Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies; Department Rizzoli RIT; Bologna Italy
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20
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Tsai SJ. Therapeutic Potential of Transcranial Focused Ultrasound for Rett Syndrome. Med Sci Monit 2016; 22:4026-4029. [PMID: 27786169 PMCID: PMC5087669 DOI: 10.12659/msm.898041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder occurring almost exclusively in females and is caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2) in the majority of cases. MeCP2 is essential for the normal function of nerve cells, including neuronal development, maturation, and synaptic activity. RTT is characterized by normal early development followed by autistic-like features, slowed brain and head growth, gait abnormalities, seizures, breathing irregularities, and cognitive disabilities. Medical management in RTT remains supportive and symptomatic. Brain-derived neurotrophic factor (BDNF) has been implicated in the pathophysiology of RTT. Recent studies have shown a phenotypic reversal by increasing BDNF expression in a RTT mouse model. Thus, manipulation of BDNF expression/signaling in the brain could be therapeutic for this disease. Transcranial focused ultrasound for (tFUS) can noninvasively focally modulate human cortical function, stimulate neurogenesis, and increase BDNF in animal studies. Consequently, tFUS may be of therapeutic potential for Rett syndrome. Further evaluation of the therapeutic effects of tFUS in Mecp2 deficient animal models is needed before clinical trials can begin.
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Affiliation(s)
- Shih-Jen Tsai
- Department of Psychiatry, Taipei Veterans General Hospital, Taiepi, Taiwan
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21
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Bowers M, Jessberger S. Linking adult hippocampal neurogenesis with human physiology and disease. Dev Dyn 2016; 245:702-9. [PMID: 26890418 DOI: 10.1002/dvdy.24396] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/12/2016] [Accepted: 02/12/2016] [Indexed: 01/13/2023] Open
Abstract
We here review the existing evidence linking adult hippocampal neurogenesis and human brain function in physiology and disease. Furthermore, we aim to point out where evidence is missing, highlight current promising avenues of investigation, and suggest future tools and approaches to foster the link between life-long neurogenesis and human brain function. Developmental Dynamics 245:702-709, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Megan Bowers
- Laboratory of Neural Plasticity, Faculty of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Sebastian Jessberger
- Laboratory of Neural Plasticity, Faculty of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
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22
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Darbro BW, Singh R, Zimmerman MB, Mahajan VB, Bassuk AG. Autism Linked to Increased Oncogene Mutations but Decreased Cancer Rate. PLoS One 2016; 11:e0149041. [PMID: 26934580 PMCID: PMC4774916 DOI: 10.1371/journal.pone.0149041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/25/2016] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorder (ASD) is one phenotypic aspect of many monogenic, hereditary cancer syndromes. Pleiotropic effects of cancer genes on the autism phenotype could lead to repurposing of oncology medications to treat this increasingly prevalent neurodevelopmental condition for which there is currently no treatment. To explore this hypothesis we sought to discover whether autistic patients more often have rare coding, single-nucleotide variants within tumor suppressor and oncogenes and whether autistic patients are more often diagnosed with neoplasms. Exome-sequencing data from the ARRA Autism Sequencing Collaboration was compared to that of a control cohort from the Exome Variant Server database revealing that rare, coding variants within oncogenes were enriched for in the ARRA ASD cohort (p<1.0 x 10(-8)). In contrast, variants were not significantly enriched in tumor suppressor genes. Phenotypically, children and adults with ASD exhibited a protective effect against cancer, with a frequency of 1.3% vs. 3.9% (p<0.001), but the protective effect decreased with age. The odds ratio of neoplasm for those with ASD relative to controls was 0.06 (95% CI: 0.02, 0.19; p<0.0001) in the 0 to 14 age group; 0.35 (95% CI: 0.14, 0.87; p = 0.024) in the 15 to 29 age group; 0.41 (95% CI: 0.15, 1.17; p = 0.095) in the 30 to 54 age group; and 0.49 (95% CI: 0.14, 1.74; p = 0.267) in those 55 and older. Both males and females demonstrated the protective effect. These findings suggest that defects in cellular proliferation, and potentially senescence, might influence both autism and neoplasm, and already approved drugs targeting oncogenic pathways might also have therapeutic value for treating autism.
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Affiliation(s)
- Benjamin W. Darbro
- Department of Pediatrics, Division of Medical Genetics, University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Program in Genetics, University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- The Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail: (BD); (AB)
| | - Rohini Singh
- Department of Pediatrics, Division of Medical Genetics, University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, Division of Pediatric Hematology/Oncology/BMT, University of Iowa, Iowa City, Iowa, United States of America
| | - M. Bridget Zimmerman
- Department of Biostatistics, University of Iowa College of Public Health, Iowa City, Iowa, United States of America
| | - Vinit B. Mahajan
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States of America
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Alexander G. Bassuk
- Interdisciplinary Program in Genetics, University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, Division of Neurology, University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program in Molecular and Cellular Biology, University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa, United States of America
- University of Iowa eHealth and eNovation Center, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail: (BD); (AB)
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Developmental Dynamics of Rett Syndrome. Neural Plast 2016; 2016:6154080. [PMID: 26942018 PMCID: PMC4752981 DOI: 10.1155/2016/6154080] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 12/23/2015] [Accepted: 12/31/2015] [Indexed: 12/31/2022] Open
Abstract
Rett Syndrome was long considered to be simply a disorder of postnatal development, with phenotypes that manifest only late in development and into adulthood. A variety of recent evidence demonstrates that the phenotypes of Rett Syndrome are present at the earliest stages of brain development, including developmental stages that define neurogenesis, migration, and patterning in addition to stages of synaptic and circuit development and plasticity. These phenotypes arise from the pleotropic effects of MeCP2, which is expressed very early in neuronal progenitors and continues to be expressed into adulthood. The effects of MeCP2 are mediated by diverse signaling, transcriptional, and epigenetic mechanisms. Attempts to reverse the effects of Rett Syndrome need to take into account the developmental dynamics and temporal impact of MeCP2 loss.
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Advancing drug discovery for neuropsychiatric disorders using patient-specific stem cell models. Mol Cell Neurosci 2016; 73:104-15. [PMID: 26826498 DOI: 10.1016/j.mcn.2016.01.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 12/17/2022] Open
Abstract
Compelling clinical, social, and economic reasons exist to innovate in the process of drug discovery for neuropsychiatric disorders. The use of patient-specific, induced pluripotent stem cells (iPSCs) now affords the ability to generate neuronal cell-based models that recapitulate key aspects of human disease. In the context of neuropsychiatric disorders, where access to physiologically active and relevant cell types of the central nervous system for research is extremely limiting, iPSC-derived in vitro culture of human neurons and glial cells is transformative. Potential applications relevant to early stage drug discovery, include support of quantitative biochemistry, functional genomics, proteomics, and perhaps most notably, high-throughput and high-content chemical screening. While many phenotypes in human iPSC-derived culture systems may prove adaptable to screening formats, addressing the question of which in vitro phenotypes are ultimately relevant to disease pathophysiology and therefore more likely to yield effective pharmacological agents that are disease-modifying treatments requires careful consideration. Here, we review recent examples of studies of neuropsychiatric disorders using human stem cell models where cellular phenotypes linked to disease and functional assays have been reported. We also highlight technical advances using genome-editing technologies in iPSCs to support drug discovery efforts, including the interpretation of the functional significance of rare genetic variants of unknown significance and for the purpose of creating cell type- and pathway-selective functional reporter assays. Additionally, we evaluate the potential of in vitro stem cell models to investigate early events of disease pathogenesis, in an effort to understand the underlying molecular mechanism, including the basis of selective cell-type vulnerability, and the potential to create new cell-based diagnostics to aid in the classification of patients and subsequent selection for clinical trials. A number of key challenges remain, including the scaling of iPSC models to larger cohorts and integration with rich clinicopathological information and translation of phenotypes. Still, the overall use of iPSC-based human cell models with functional cellular and biochemical assays holds promise for supporting the discovery of next-generation neuropharmacological agents for the treatment and ultimately prevention of a range of severe mental illnesses.
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Are there roles for brain cell senescence in aging and neurodegenerative disorders? Biogerontology 2014; 15:643-60. [PMID: 25305051 DOI: 10.1007/s10522-014-9532-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/13/2014] [Indexed: 12/30/2022]
Abstract
The term cellular senescence was introduced more than five decades ago to describe the state of growth arrest observed in aging cells. Since this initial discovery, the phenotypes associated with cellular senescence have expanded beyond growth arrest to include alterations in cellular metabolism, secreted cytokines, epigenetic regulation and protein expression. Recently, senescence has been shown to play an important role in vivo not only in relation to aging, but also during embryonic development. Thus, cellular senescence serves different purposes and comprises a wide range of distinct phenotypes across multiple cell types. Whether all cell types, including post-mitotic neurons, are capable of entering into a senescent state remains unclear. In this review we examine recent data that suggest that cellular senescence plays a role in brain aging and, notably, may not be limited to glia but also neurons. We suggest that there is a high level of similarity between some of the pathological changes that occur in the brain in Alzheimer's and Parkinson's diseases and those phenotypes observed in cellular senescence, leading us to propose that neurons and glia can exhibit hallmarks of senescence previously documented in peripheral tissues.
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Translation: screening for novel therapeutics with disease-relevant cell types derived from human stem cell models. Biol Psychiatry 2014; 75:952-60. [PMID: 23876186 PMCID: PMC3815991 DOI: 10.1016/j.biopsych.2013.05.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/02/2013] [Accepted: 05/29/2013] [Indexed: 12/23/2022]
Abstract
The advent of somatic cell reprogramming technologies-which enables the generation of patient-specific, induced pluripotent stem cell and other trans-differentiated human neuronal cell models-provides new means of gaining insight into the molecular mechanisms and neural substrates of psychiatric disorders. By allowing a more precise understanding of genotype-phenotype relationship in disease-relevant human cell types, the use of reprogramming technologies in tandem with emerging genome engineering approaches provides a previously "missing link" between basic research and translational efforts. In this review, we summarize advances in applying human pluripotent stem cell and reprogramming technologies to generate specific neural subtypes with a focus on the use of these in vitro systems for the discovery of small molecule-probes and novel therapeutics. Examples are given where human cell models of psychiatric disorders have begun to reveal new mechanistic insight into pathophysiology and simultaneously have provided the foundation for developing disease-relevant, phenotypic assays suitable for both functional genomic and chemical screens. A number of areas for future research are discussed, including the need to develop robust methodology for the reproducible, large-scale production of disease-relevant neural cell types in formats compatible with high-throughput screening modalities, including high-content imaging, multidimensional, signature-based screening, and in vitro network with multielectrode arrays. Limitations, including the challenges in recapitulating neurocircuits and non-cell autonomous phenotypes are discussed. Although these technologies are still in active development, we conclude that, as our understanding of how to efficiently generate and probe the plasticity of patient-specific stem models improves, their utility is likely to advance rapidly.
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Redox imbalance and morphological changes in skin fibroblasts in typical Rett syndrome. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:195935. [PMID: 24987493 PMCID: PMC4060159 DOI: 10.1155/2014/195935] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/09/2014] [Accepted: 05/12/2014] [Indexed: 12/22/2022]
Abstract
Evidence of oxidative stress has been reported in the blood of patients with Rett syndrome (RTT), a neurodevelopmental disorder mainly caused by mutations in the gene encoding the Methyl-CpG-binding protein 2. Little is known regarding the redox status in RTT cellular systems and its relationship with the morphological phenotype. In RTT patients (n = 16) we investigated four different oxidative stress markers, F2-Isoprostanes (F2-IsoPs), F4-Neuroprostanes (F4-NeuroPs), nonprotein bound iron (NPBI), and (4-HNE PAs), and glutathione in one of the most accessible cells, that is, skin fibroblasts, and searched for possible changes in cellular/intracellular structure and qualitative modifications of synthesized collagen. Significantly increased F4-NeuroPs (12-folds), F2-IsoPs (7.5-folds) NPBI (2.3-folds), 4-HNE PAs (1.48-folds), and GSSG (1.44-folds) were detected, with significantly decreased GSH (-43.6%) and GSH/GSSG ratio (-3.05 folds). A marked dilation of the rough endoplasmic reticulum cisternae, associated with several cytoplasmic multilamellar bodies, was detectable in RTT fibroblasts. Colocalization of collagen I and collagen III, as well as the percentage of type I collagen as derived by semiquantitative immunofluorescence staining analyses, appears to be significantly reduced in RTT cells. Our findings indicate the presence of a redox imbalance and previously unrecognized morphological skin fibroblast abnormalities in RTT patients.
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Abstract
Rett syndrome (RTT) is a severe and progressive neurological disorder, which mainly affects young females. Mutations of the methyl-CpG binding protein 2 (MECP2) gene are the most prevalent cause of classical RTT cases. MECP2 mutations or altered expression are also associated with a spectrum of neurodevelopmental disorders such as autism spectrum disorders with recent links to fetal alcohol spectrum disorders. Collectively, MeCP2 relation to these neurodevelopmental disorders highlights the importance of understanding the molecular mechanisms by which MeCP2 impacts brain development, mental conditions, and compromised brain function. Since MECP2 mutations were discovered to be the primary cause of RTT, a significant progress has been made in the MeCP2 research, with respect to the expression, function and regulation of MeCP2 in the brain and its contribution in RTT pathogenesis. To date, there have been intensive efforts in designing effective therapeutic strategies for RTT benefiting from mouse models and cells collected from RTT patients. Despite significant progress in MeCP2 research over the last few decades, there is still a knowledge gap between the in vitro and in vivo research findings and translating these findings into effective therapeutic interventions in human RTT patients. In this review, we will provide a synopsis of Rett syndrome as a severe neurological disorder and will discuss the role of MeCP2 in RTT pathophysiology.
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Glutamate-induced epigenetic and morphological changes allow rat Müller cell dedifferentiation but not further acquisition of a photoreceptor phenotype. Neuroscience 2013; 254:347-60. [DOI: 10.1016/j.neuroscience.2013.09.048] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 11/22/2022]
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Liyanage VRB, Zachariah RM, Rastegar M. Decitabine alters the expression of Mecp2 isoforms via dynamic DNA methylation at the Mecp2 regulatory elements in neural stem cells. Mol Autism 2013; 4:46. [PMID: 24238559 PMCID: PMC3900258 DOI: 10.1186/2040-2392-4-46] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 10/01/2013] [Indexed: 01/01/2023] Open
Abstract
Background Aberrant MeCP2 expression in brain is associated with neurodevelopmental disorders including autism. In the brain of stressed mouse and autistic human patients, reduced MeCP2 expression is correlated with Mecp2/MECP2 promoter hypermethylation. Altered expression of MeCP2 isoforms (MeCP2E1 and MeCP2E2) is associated with neurological disorders, highlighting the importance of proper regulation of both isoforms. While known regulatory elements (REs) within the MECP2/Mecp2 promoter and intron 1 are involved in MECP2/Mecp2 regulation, Mecp2 isoform-specific regulatory mechanisms are unknown. We hypothesized that DNA methylation at these REs may impact the expression of Mecp2 isoforms. Methods We used a previously characterized in vitro differentiating neural stem cell (NSC) system to investigate the interplay between Mecp2 isoform-specific expression and DNA methylation at the Mecp2 REs. We studied altered expression of Mecp2 isoforms, affected by global DNA demethylation and remethylation, induced by exposure and withdrawal of decitabine (5-Aza-2′-deoxycytidine). Further, we performed correlation analysis between DNA methylation at the Mecp2 REs and the expression of Mecp2 isoforms after decitabine exposure and withdrawal. Results At different stages of NSC differentiation, Mecp2 isoforms showed reciprocal expression patterns associated with minor, but significant changes in DNA methylation at the Mecp2 REs. Decitabine treatment induced Mecp2e1/MeCP2E1 (but not Mecp2e2) expression at day (D) 2, associated with DNA demethylation at the Mecp2 REs. In contrast, decitabine withdrawal downregulated both Mecp2 isoforms to different extents at D8, without affecting DNA methylation at the Mecp2 REs. NSC cell fate commitment was minimally affected by decitabine under tested conditions. Expression of both isoforms negatively correlated with methylation at specific regions of the Mecp2 promoter, both at D2 and D8. The correlation between intron 1 methylation and Mecp2e1 (but not Mecp2e2) varied depending on the stage of NSC differentiation (D2: negative; D8: positive). Conclusions Our results show the correlation between the expression of Mecp2 isoforms and DNA methylation in differentiating NSC, providing insights on the potential role of DNA methylation at the Mecp2 REs in Mecp2 isoform-specific expression. The ability of decitabine to induce Mecp2e1/MeCP2E1, but not Mecp2e2 suggests differential sensitivity of Mecp2 isoforms to decitabine and is important for future drug therapies for autism.
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Affiliation(s)
| | | | - Mojgan Rastegar
- Regenerative Medicine Program, Department of Biochemistry and Medical Genetics, Faculty of Medicine, University of Manitoba, Rm, 627, Basic Medical Sciences Bldg,, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada.
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31
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Sheikh TI, Mittal K, Willis MJ, Vincent JB. A synonymous change, p.Gly16Gly in MECP2 Exon 1, causes a cryptic splice event in a Rett syndrome patient. Orphanet J Rare Dis 2013; 8:108. [PMID: 23866855 PMCID: PMC3729535 DOI: 10.1186/1750-1172-8-108] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/12/2013] [Indexed: 12/01/2022] Open
Abstract
Background Mutations in MECP2 are the main cause of Rett Syndrome. To date, no pathogenic synonymous MECP2 mutation has yet been identified. Here, we investigated a de novo synonymous variant c.48C>T (p.Gly16Gly) identified in a girl presenting with a typical RTT phenotype. Methods In silico analyses to predict the effects of sequence variation on mRNA splicing were employed, followed by sequencing and quantification of lymphocyte mRNAs from the subject for splice variants MECP2_E1 and MECP2_E2. Results Analysis of mRNA confirmed predictions that this synonymous mutation activates a splice-donor site at an early position in exon 1, leading to a deletion (r.[=, 48_63del]), codon frameshift and premature stop codon (p.Glu17Lysfs*16) for MECP2_E1. For MECP2_E2, the same premature splice site is used, but as this is located in the 5′untranslated region, no effect on the amino acid sequence is predicted. Quantitative analysis that specifically measured this cryptic splice variant also revealed a significant decrease in the quantity of the correct MECP2_E1 transcript, which indicates that this is the etiologically significant mutation in this patient. Conclusion These findings suggest that synonymous variants of MECP2 as well as other known disease genes—and de novo variants in particular— should be re-evaluated for potential effects on splicing.
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Affiliation(s)
- Taimoor I Sheikh
- Molecular Neuropsychiatry & Development Lab, Campbell Family Mental Health Research Institute, Centre for Addiction & Mental Health, Toronto, Canada
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Functional implications of hippocampal adult neurogenesis in intellectual disabilities. Amino Acids 2013; 45:113-31. [DOI: 10.1007/s00726-013-1489-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 03/15/2013] [Indexed: 12/19/2022]
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De Felice C, Signorini C, Leoncini S, Pecorelli A, Durand T, Valacchi G, Ciccoli L, Hayek J. The role of oxidative stress in Rett syndrome: an overview. Ann N Y Acad Sci 2012; 1259:121-35. [PMID: 22758644 DOI: 10.1111/j.1749-6632.2012.06611.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The main cause of Rett syndrome (RTT), a pervasive development disorder almost exclusively affecting females, is a mutation in the methyl-CpG binding protein 2 (MeCP2) gene. To date, no cure for RTT exists, although disease reversibility has been demonstrated in animal models. Emerging evidence from our and other laboratories indicates a potential role of oxidative stress (OS) in RTT. This review examines the current state of the knowledge on the role of OS in explaining the natural history, genotype-phenotype correlation, and clinical heterogeneity of the human disease. Biochemical evidence of OS appears to be related to neurological symptom severity, mutation type, and clinical presentation. These findings pave the way for potential new genetic downstream therapeutic strategies aimed at improving patient quality of life. Further efforts in the near future are needed for investigating the yet unexplored "black box" between the MeCP2 gene mutation and subsequent OS derangement.
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Affiliation(s)
- Claudio De Felice
- Neonatal Intensive Care Unit University Hospital, Azienda Ospedaliera Universitaria Senese of Siena, Siena, Italy.
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Olynik BM, Rastegar M. The genetic and epigenetic journey of embryonic stem cells into mature neural cells. Front Genet 2012; 3:81. [PMID: 22629283 PMCID: PMC3355330 DOI: 10.3389/fgene.2012.00081] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 04/25/2012] [Indexed: 12/14/2022] Open
Abstract
Epigenetic changes occur throughout life from embryonic development into adulthood. This results in the timely expression of developmentally important genes, determining the morphology and identity of different cell types and tissues within the body. Epigenetics regulate gene expression and cellular morphology through multiple mechanisms without alteration in the underlying DNA sequences. Different epigenetic mechanisms include chromatin condensation, post-translational modification of histone proteins, DNA cytosine marks, and the activity of non-coding RNA molecules. Epigenetics play key roles in development, stem cell differentiation, and have high impact in human disease. In this review, we will discuss our current knowledge about these epigenetic mechanisms, with a focus on histone and DNA marks. We will then talk about the genetics and epigenetics of embryonic stem cell self-renewal and differentiation into neural stem cells, and further into specific neuronal cell types.
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Affiliation(s)
- Brendan M Olynik
- Regenerative Medicine Program, Faculty of Medicine, University of Manitoba Winnipeg, MB, Canada
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