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Guo X, Hong P, Xiong S, Yan Y, Xie H, Guan JS. Kdm4a is an activity downregulated barrier to generate engrams for memory separation. Nat Commun 2024; 15:5887. [PMID: 39003305 PMCID: PMC11246488 DOI: 10.1038/s41467-024-50218-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 07/01/2024] [Indexed: 07/15/2024] Open
Abstract
Memory engrams are a subset of learning activated neurons critical for memory recall, consolidation, extinction and separation. While the transcriptional profile of engrams after learning suggests profound neural changes underlying plasticity and memory formation, little is known about how memory engrams are selected and allocated. As epigenetic factors suppress memory formation, we developed a CRISPR screening in the hippocampus to search for factors controlling engram formation. We identified histone lysine-specific demethylase 4a (Kdm4a) as a negative regulator for engram formation. Kdm4a is downregulated after neural activation and controls the volume of mossy fiber boutons. Mechanistically, Kdm4a anchors to the exonic region of Trpm7 gene loci, causing the stalling of nascent RNAs and allowing burst transcription of Trpm7 upon the dismissal of Kdm4a. Furthermore, the YTH domain containing protein 2 (Ythdc2) recruits Kdm4a to the Trpm7 gene and stabilizes nascent RNAs. Reducing the expression of Kdm4a in the hippocampus via genetic manipulation or artificial neural activation facilitated the ability of pattern separation in rodents. Our work indicates that Kdm4a is a negative regulator of engram formation and suggests a priming state to generate a separate memory.
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Affiliation(s)
- Xiuxian Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Pengfei Hong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Songhai Xiong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yuze Yan
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Hong Xie
- Institute of Photonic Chips, School of Artificial Intelligence Science and Technology, University of Shanghai for Science and Technology, Shanghai, China.
| | - Ji-Song Guan
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
- State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai, China.
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2
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Medina J, Zhou Z. Unlock the potential: Auditory-evoked event-related potential (ERP) as a treatment-responsive biomarker for Rett syndrome. Neurotherapeutics 2024; 21:e00389. [PMID: 38944637 DOI: 10.1016/j.neurot.2024.e00389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Accepted: 06/15/2024] [Indexed: 07/01/2024] Open
Affiliation(s)
- Joanna Medina
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhaolan Zhou
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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3
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Dong HW, Weiss K, Baugh K, Meadows MJ, Niswender CM, Neul JL. Potentiation of the muscarinic acetylcholine receptor 1 modulates neurophysiological features in a mouse model of Rett syndrome. Neurotherapeutics 2024; 21:e00384. [PMID: 38880672 DOI: 10.1016/j.neurot.2024.e00384] [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: 04/17/2024] [Revised: 06/07/2024] [Accepted: 06/09/2024] [Indexed: 06/18/2024] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder primarily caused by mutations in the X chromosome-linked gene Methyl-CpG Binding Protein 2 (MECP2). Restoring MeCP2 expression after disease onset in a mouse model of RTT reverses phenotypes, providing hope for development of treatments for RTT. Translatable biomarkers of improvement and treatment responses have the potential to accelerate both preclinical and clinical evaluation of targeted therapies in RTT. Studies in people with and mouse models of RTT have identified neurophysiological features, such as auditory event-related potentials, that correlate with disease severity, suggesting that they could be useful as biomarkers of disease improvement or early treatment response. We recently demonstrated that treatment of RTT mice with a positive allosteric modulator (PAM) of muscarinic acetylcholine subtype 1 receptor (M1) improved phenotypes, suggesting that modulation of M1 activity is a potential therapy in RTT. To evaluate whether neurophysiological features could be useful biomarkers to assess the effects of M1 PAM treatment, we acutely administered the M1 PAM VU0486846 (VU846) at doses of 1, 3, 10 and 30 mg/kg in wildtype and RTT mice. This resulted in an inverted U-shaped dose response with maximal improvement of AEP features at 3 mg/kg but with no marked effect on basal EEG power or epileptiform discharges in RTT mice and no significant changes in wildtype mice. These findings suggest that M1 potentiation can improve neural circuit synchrony to auditory stimuli in RTT mice and that neurophysiological features have potential as pharmacodynamic or treatment-responsive biomarkers for preclinical and clinical evaluation of putative therapies in RTT.
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Affiliation(s)
- Hong-Wei Dong
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, USA; Vanderbilt University Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kelly Weiss
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Warren Center for Neuroscience Drug Discovery, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Kathryn Baugh
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, USA
| | - Mac J Meadows
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Warren Center for Neuroscience Drug Discovery, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Colleen M Niswender
- Vanderbilt University Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Warren Center for Neuroscience Drug Discovery, School of Medicine, Vanderbilt University, Nashville, TN, USA; Vanderbilt Institute for Chemical Biology, Nashville, TN, USA; Vanderbilt Brain Institute, Nashville, TN, USA.
| | - Jeffrey L Neul
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, USA; Vanderbilt University Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Vanderbilt Brain Institute, Nashville, TN, USA.
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4
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Zhang H, Liu L, Li M. Mini-review of DNA Methylation Detection Techniques and Their Potential Applications in Disease Diagnosis, Prognosis, and Treatment. ACS Sens 2024; 9:1089-1103. [PMID: 38365574 DOI: 10.1021/acssensors.3c02328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2024]
Abstract
DNA methylation is the dominant epigenetic mechanism for regulating gene expression in mammals, playing crucial roles in development, differentiation, and tissue homeostasis. Aberrations in DNA methylation are closely associated with the potential onset of various diseases. Consequently, numerous DNA methylation detection techniques have been successively developed. These methods not only facilitate the exploration of disease mechanisms but also hold significant promise for the development of diagnostic and prognostic strategies. In this Perspective, we present a comprehensive overview of commonly employed DNA methylation detection techniques as well as biosensing based on their underlying analytical techniques. For its medical applications, we begin by examining the pathogenesis of different diseases and then proceed to discuss how relevant technologies are applied in the context of these specific medical conditions. Additionally, we briefly discuss the current limitations of these techniques and highlight future challenges in advancing methylation detection and analysis methodologies.
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Affiliation(s)
- Huaming Zhang
- Institute for Advanced Materials, School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Liu
- Institute for Advanced Materials, School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Min Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
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Martinez D, Jiang E, Zhou Z. Overcoming genetic and cellular complexity to study the pathophysiology of X-linked intellectual disabilities. J Neurodev Disord 2024; 16:5. [PMID: 38424476 PMCID: PMC10902969 DOI: 10.1186/s11689-024-09517-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 02/04/2024] [Indexed: 03/02/2024] Open
Abstract
X-linked genetic causes of intellectual disability (ID) account for a substantial proportion of cases and remain poorly understood, in part due to the heterogeneous expression of X-linked genes in females. This is because most genes on the X chromosome are subject to random X chromosome inactivation (XCI) during early embryonic development, which results in a mosaic pattern of gene expression for a given X-linked mutant allele. This mosaic expression produces substantial complexity, especially when attempting to study the already complicated neural circuits that underly behavior, thus impeding the understanding of disease-related pathophysiology and the development of therapeutics. Here, we review a few selected X-linked forms of ID that predominantly affect heterozygous females and the current obstacles for developing effective therapies for such disorders. We also propose a genetic strategy to overcome the complexity presented by mosaicism in heterozygous females and highlight specific tools for studying synaptic and circuit mechanisms, many of which could be shared across multiple forms of intellectual disability.
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Affiliation(s)
- Dayne Martinez
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
- Medical Scientist Training Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
| | - Evan Jiang
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
- Medical Scientist Training Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
| | - Zhaolan Zhou
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA.
- Medical Scientist Training Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA.
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA.
- Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
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Cording KR, Bateup HS. Altered motor learning and coordination in mouse models of autism spectrum disorder. Front Cell Neurosci 2023; 17:1270489. [PMID: 38026686 PMCID: PMC10663323 DOI: 10.3389/fncel.2023.1270489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/25/2023] [Indexed: 12/01/2023] Open
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with increasing prevalence. Over 1,000 risk genes have now been implicated in ASD, suggesting diverse etiology. However, the diagnostic criteria for the disorder still comprise two major behavioral domains - deficits in social communication and interaction, and the presence of restricted and repetitive patterns of behavior (RRBs). The RRBs associated with ASD include both stereotyped repetitive movements and other motor manifestations including changes in gait, balance, coordination, and motor skill learning. In recent years, the striatum, the primary input center of the basal ganglia, has been implicated in these ASD-associated motor behaviors, due to the striatum's role in action selection, motor learning, and habit formation. Numerous mouse models with mutations in ASD risk genes have been developed and shown to have alterations in ASD-relevant behaviors. One commonly used assay, the accelerating rotarod, allows for assessment of both basic motor coordination and motor skill learning. In this corticostriatal-dependent task, mice walk on a rotating rod that gradually increases in speed. In the extended version of this task, mice engage striatal-dependent learning mechanisms to optimize their motor routine and stay on the rod for longer periods. This review summarizes the findings of studies examining rotarod performance across a range of ASD mouse models, and the resulting implications for the involvement of striatal circuits in ASD-related motor behaviors. While performance in this task is not uniform across mouse models, there is a cohort of models that show increased rotarod performance. A growing number of studies suggest that this increased propensity to learn a fixed motor routine may reflect a common enhancement of corticostriatal drive across a subset of mice with mutations in ASD-risk genes.
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Affiliation(s)
- Katherine R. Cording
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Helen S. Bateup
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
- Molecular and Cell Biology Department, University of California, Berkeley, Berkeley, CA, United States
- Chan Zuckerberg Biohub, San Francisco, CA, United States
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7
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Kostanian D, Rebreikina A, Voinova V, Sysoeva O. Effect of presentation rate on auditory processing in Rett syndrome: event-related potential study. Mol Autism 2023; 14:40. [PMID: 37885019 PMCID: PMC10605980 DOI: 10.1186/s13229-023-00566-1] [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: 07/26/2023] [Accepted: 09/05/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Rett syndrome (RS) is a rare neurodevelopmental disorder characterized by mutations in the MECP2 gene. Patients with RS have severe motor abnormalities and are often unable to walk, use hands and speak. The preservation of perceptual and cognitive functions is hard to assess, while clinicians and care-givers point out that these patients need more time to process information than typically developing peers. Neurophysiological correlates of auditory processing have been also found to be distorted in RS, but sound presentation rates were relatively quick in these studies (stimulus onset asynchrony, SOA < 1000 ms). As auditory event-related potential (ERP) is typically increased with prolongation of SOA we aim to study if SOA prolongation might compensate for observed abnormalities. METHODS We presented a repetitive stimulus (1000 Hz) at three different SOAs of 900 ms, 1800 ms, and 3600 ms in children with RS (N = 24, Mean age = 9.0 ± 3.1) and their typical development (TD) peers (N = 27, Mean age = 9.7 ± 3.4) while recording 28-channels electroencephalogram, EEG. Some RS participants (n = 10) did not show clear ERP and were excluded from the analysis. RESULTS Major ERP components (here assessed as N1P1 and P2N1 peak-to-peak values) were smaller at SOA 900 than at longer SOAs in both groups, pointing out that the basic mechanism of adaptation in the auditory system is preserved in at least in RS patients with evident ERPs. At the same time the latencies of these components were significantly delayed in the RS than in TD. Moreover, late components (P2N1 and N2P2) were drastically reduced in Rett syndrome irrespective of the SOA, suggesting a largely affected mechanism of integration of upcoming sensory input with memory. Moreover, developmental stagnation of auditory ERP characterized patients with RS: absence of typical P2N1 enlargement and P1 and N1 shortening with age at least for shortest SOA. LIMITATIONS We could not figure out the cause for the high percentage of no-evident ERP RS participants and our final sample of the RS group was rather small. Also, our study did not include a control clinical group. CONCLUSIONS Thus, auditory ERPs inform us about abnormalities within auditory processing that cannot be fully overcomed by slowing presentation rate.
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Affiliation(s)
- Daria Kostanian
- Center for Cognitive Sciences, Sirius University of Science and Technology, Olympic Ave 1, Sochi, Russia, 354340.
| | - Anna Rebreikina
- Center for Cognitive Sciences, Sirius University of Science and Technology, Olympic Ave 1, Sochi, Russia, 354340
- Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia, 117485
| | - Victoria Voinova
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov, Russian National Research Medical University, Ministry of Health of Russian Federation, Moscow, Russia, 125412
| | - Olga Sysoeva
- Center for Cognitive Sciences, Sirius University of Science and Technology, Olympic Ave 1, Sochi, Russia, 354340
- Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia, 117485
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8
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Zhou J, Cattoglio C, Shao Y, Tirumala HP, Vetralla C, Bajikar SS, Li Y, Chen H, Wang Q, Wu Z, Tang B, Zahabiyon M, Bajic A, Meng X, Ferrie JJ, LaGrone A, Zhang P, Kim JJ, Tang J, Liu Z, Darzacq X, Heintz N, Tjian R, Zoghbi HY. A novel pathogenic mutation of MeCP2 impairs chromatin association independent of protein levels. Genes Dev 2023; 37:883-900. [PMID: 37890975 PMCID: PMC10691473 DOI: 10.1101/gad.350733.123] [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: 04/20/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023]
Abstract
Loss-of-function mutations in MECP2 cause Rett syndrome (RTT), a severe neurological disorder that mainly affects girls. Mutations in MECP2 do occur in males occasionally and typically cause severe encephalopathy and premature lethality. Recently, we identified a missense mutation (c.353G>A, p.Gly118Glu [G118E]), which has never been seen before in MECP2, in a young boy who suffered from progressive motor dysfunction and developmental delay. To determine whether this variant caused the clinical symptoms and study its functional consequences, we established two disease models, including human neurons from patient-derived iPSCs and a knock-in mouse line. G118E mutation partially reduces MeCP2 abundance and its DNA binding, and G118E mice manifest RTT-like symptoms seen in the patient, affirming the pathogenicity of this mutation. Using live-cell and single-molecule imaging, we found that G118E mutation alters MeCP2's chromatin interaction properties in live neurons independently of its effect on protein levels. Here we report the generation and characterization of RTT models of a male hypomorphic variant and reveal new insight into the mechanism by which this pathological mutation affects MeCP2's chromatin dynamics. Our ability to quantify protein dynamics in disease models lays the foundation for harnessing high-resolution single-molecule imaging as the next frontier for developing innovative therapies for RTT and other diseases.
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Affiliation(s)
- Jian Zhou
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Claudia Cattoglio
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
| | - Yingyao Shao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Harini P Tirumala
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Carlo Vetralla
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
- School of Medicine and Surgery, University of Milan-Bicocca, Milano 20126, Italy
| | - Sameer S Bajikar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Yan Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Hu Chen
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Qi Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zhenyu Wu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Bing Tang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mahla Zahabiyon
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Aleksandar Bajic
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Xiangling Meng
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jack J Ferrie
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
| | - Anel LaGrone
- Advanced Technology Cores, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Ping Zhang
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jean J Kim
- Advanced Technology Cores, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Cellular Biology, Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jianrong Tang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xavier Darzacq
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA
| | - Robert Tjian
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
| | - Huda Y Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA;
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA
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Mykins M, Layo-Carris D, Dunn LR, Skinner DW, McBryar AH, Perez S, Shultz TR, Willems A, Lau BYB, Hong T, Krishnan K. Wild-type MECP2 expression coincides with age-dependent sensory phenotypes in a female mouse model for Rett syndrome. J Neurosci Res 2023; 101:1236-1258. [PMID: 37026482 PMCID: PMC10332853 DOI: 10.1002/jnr.25190] [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: 09/14/2022] [Revised: 02/07/2023] [Accepted: 03/12/2023] [Indexed: 04/08/2023]
Abstract
Rett syndrome is characterized by an early period of typical development and then, regression of learned motor and speech skills in girls. Loss of MECP2 protein is thought to cause Rett syndrome phenotypes. The specific underlying mechanisms from typical developmental trajectory to regression features throughout life are unclear. Lack of established timelines to study the molecular, cellular, and behavioral features of regression in female mouse models is a major contributing factor. Due to random X-chromosome inactivation, female patients with Rett syndrome and female mouse models for Rett syndrome (Mecp2Heterozygous , Het) express a functional copy of wild-type MECP2 protein in approximately half of all cells. As MECP2 expression is regulated during early postnatal development and experience, we characterized the expression of wild-type MECP2 in the primary somatosensory cortex of female Het mice. Here, we report increased MECP2 levels in non-parvalbumin-positive neurons of 6-week-old adolescent Het relative to age-matched wild-type controls, while also displaying typical levels of perineuronal net expression in the barrel field subregion of the primary somatosensory cortex, mild tactile sensory perception deficits, and efficient pup retrieval behavior. In contrast, 12-week-old adult Het express MECP2 at levels similar to age-matched wild-type mice, show increased perineuronal net expression in the cortex, and display significant tactile sensory perception deficits. Thus, we have identified a set of behavioral metrics and the cellular substrates to study regression during a specific time in the female Het mouse model, which coincides with changes in wild-type MECP2 expression. We speculate that the precocious increase in MECP2 expression within specific cell types of adolescent Het may provide compensatory benefits at the behavioral level, while the inability to further increase MECP2 levels leads to regressive behavioral phenotypes over time.
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Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Dana Layo-Carris
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Logan Reid Dunn
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - David Wilson Skinner
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Alexandra Hart McBryar
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Sarah Perez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Trinity Rose Shultz
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Andrew Willems
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Billy You Bun Lau
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Tian Hong
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
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10
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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: 0] [Impact Index Per Article: 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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Xu B, Ho Y, Fasolino M, Medina J, O’Brien WT, Lamonica JM, Nugent E, Brodkin ES, Fuccillo MV, Bucan M, Zhou Z. Allelic contribution of Nrxn1α to autism-relevant behavioral phenotypes in mice. PLoS Genet 2023; 19:e1010659. [PMID: 36848371 PMCID: PMC9997995 DOI: 10.1371/journal.pgen.1010659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/09/2023] [Accepted: 02/08/2023] [Indexed: 03/01/2023] Open
Abstract
Copy number variations (CNVs) in the Neurexin 1 (NRXN1) gene, which encodes a presynaptic protein involved in neurotransmitter release, are some of the most frequently observed single-gene variants associated with autism spectrum disorder (ASD). To address the functional contribution of NRXN1 CNVs to behavioral phenotypes relevant to ASD, we carried out systematic behavioral phenotyping of an allelic series of Nrxn1 mouse models: one carrying promoter and exon 1 deletion abolishing Nrxn1α transcription, one carrying exon 9 deletion disrupting Nrxn1α protein translation, and one carrying an intronic deletion with no observable effect on Nrxn1α expression. We found that homozygous loss of Nrxn1α resulted in enhanced aggression in males, reduced affiliative social behaviors in females, and significantly altered circadian activities in both sexes. Heterozygous or homozygous loss of Nrxn1α affected the preference for social novelty in male mice, and notably, enhanced repetitive motor skills and motor coordination in both sexes. In contrast, mice bearing an intronic deletion of Nrxn1 did not display alterations in any of the behaviors assessed. These findings demonstrate the importance of Nrxn1α gene dosage in regulating social, circadian, and motor functions, and the variables of sex and genomic positioning of CNVs in the expression of autism-related phenotypes. Importantly, mice with heterozygous loss of Nrxn1, as found in numerous autistic individuals, show an elevated propensity to manifest autism-related phenotypes, supporting the use of models with this genomic architecture to study ASD etiology and assess additional genetic variants associated with autism.
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Affiliation(s)
- Bing Xu
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Urology, The First Affiliated Hospital of Shandong First Medical University & Shandong Province Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Organ Transplantation and Nephrosis, Shandong Institute of Nephrology, Jinan, Shandong, China
| | - Yugong Ho
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Maria Fasolino
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Joanna Medina
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - William Timothy O’Brien
- Preclinical Models Core, Intellectual and Developmental Disability Research Center (IDDRC) Children’s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Janine M. Lamonica
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Erin Nugent
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Edward S. Brodkin
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Marc V. Fuccillo
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Maja Bucan
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Zhaolan Zhou
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Autism Spectrum Program of Excellence (ASPE), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Preclinical Models Core, Intellectual and Developmental Disability Research Center (IDDRC) Children’s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
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12
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The role of DNA methylation in progression of neurological disorders and neurodegenerative diseases as well as the prospect of using DNA methylation inhibitors as therapeutic agents for such disorders. IBRO Neurosci Rep 2022; 14:28-37. [PMID: 36590248 PMCID: PMC9794904 DOI: 10.1016/j.ibneur.2022.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 11/23/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Genome-wide studies related to neurological disorders and neurodegenerative diseases have pointed to the role of epigenetic changes such as DNA methylation, histone modification, and noncoding RNAs. DNA methylation machinery controls the dynamic regulation of methylation patterns in discrete brain regions. Objective This review aims to describe the role of DNA methylation in inhibiting and progressing neurological and neurodegenerative disorders and therapeutic approaches. Methods A Systematic search of PubMed, Web of Science, and Cochrane Library was conducted for all qualified studies from 2000 to 2022. Results For the current need of time, we have focused on the DNA methylation role in neurological and neurodegenerative diseases and the expression of genes involved in neurodegeneration such as Alzheimer's, Depression, and Rett Syndrome. Finally, it appears that the various epigenetic changes do not occur separately and that DNA methylation and histone modification changes occur side by side and affect each other. We focused on the role of modification of DNA methylation in several genes associated with depression (NR3C1, NR3C2, CRHR1, SLC6A4, BDNF, and FKBP5), Rett syndrome (MECP2), Alzheimer's, depression (APP, BACE1, BIN1 or ANK1) and Parkinson's disease (SNCA), as well as the co-occurring modifications to histones and expression of non-coding RNAs. Understanding these epigenetic changes and their interactions will lead to better treatment strategies. Conclusion This review captures the state of understanding of the epigenetics of neurological and neurodegenerative diseases. With new epigenetic mechanisms and targets undoubtedly on the horizon, pharmacological modulation and regulation of epigenetic processes in the brain holds great promise for therapy.
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Guo Y, Wang YY, Sun TT, Xu JJ, Yang P, Ma CY, Guan WJ, Wang CJ, Liu GF, Liu CQ. Neural progenitor cells derived from fibroblasts induced by small molecule compounds under hypoxia for treatment of Parkinson's disease in rats. Neural Regen Res 2022; 18:1090-1098. [PMID: 36254998 PMCID: PMC9827776 DOI: 10.4103/1673-5374.355820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Neural progenitor cells (NPCs) capable of self-renewal and differentiation into neural cell lineages offer broad prospects for cell therapy for neurodegenerative diseases. However, cell therapy based on NPC transplantation is limited by the inability to acquire sufficient quantities of NPCs. Previous studies have found that a chemical cocktail of valproic acid, CHIR99021, and Repsox (VCR) promotes mouse fibroblasts to differentiate into NPCs under hypoxic conditions. Therefore, we used VCR (0.5 mM valproic acid, 3 μM CHIR99021, and 1 μM Repsox) to induce the reprogramming of rat embryonic fibroblasts into NPCs under a hypoxic condition (5%). These NPCs exhibited typical neurosphere-like structures that can express NPC markers, such as Nestin, SRY-box transcription factor 2, and paired box 6 (Pax6), and could also differentiate into multiple types of functional neurons and astrocytes in vitro. They had similar gene expression profiles to those of rat brain-derived neural stem cells. Subsequently, the chemically-induced NPCs (ciNPCs) were stereotactically transplanted into the substantia nigra of 6-hydroxydopamine-lesioned parkinsonian rats. We found that the ciNPCs exhibited long-term survival, migrated long distances, and differentiated into multiple types of functional neurons and glial cells in vivo. Moreover, the parkinsonian behavioral defects of the parkinsonian model rats grafted with ciNPCs showed remarkable functional recovery. These findings suggest that rat fibroblasts can be directly transformed into NPCs using a chemical cocktail of VCR without introducing exogenous factors, which may be an attractive donor material for transplantation therapy for Parkinson's disease.
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Affiliation(s)
- Yu Guo
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Yuan-Yuan Wang
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Ting-Ting Sun
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Jia-Jia Xu
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Pan Yang
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Cai-Yun Ma
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China,National Germplasm Resource Center for Domestic Animals, Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Wei-Jun Guan
- National Germplasm Resource Center for Domestic Animals, Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Chun-Jing Wang
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Gao-Feng Liu
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China,Correspondence to: Chang-Qing Liu, ; Gao-Feng Liu, .
| | - Chang-Qing Liu
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, Anhui Province, China,Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA,Correspondence to: Chang-Qing Liu, ; Gao-Feng Liu, .
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14
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Wilde M, Constantin L, Thorne PR, Montgomery JM, Scott EK, Cheyne JE. Auditory processing in rodent models of autism: a systematic review. J Neurodev Disord 2022; 14:48. [PMID: 36042393 PMCID: PMC9429780 DOI: 10.1186/s11689-022-09458-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 08/07/2022] [Indexed: 11/19/2022] Open
Abstract
Autism is a complex condition with many traits, including differences in auditory sensitivity. Studies in human autism are plagued by the difficulty of controlling for aetiology, whereas studies in individual rodent models cannot represent the full spectrum of human autism. This systematic review compares results in auditory studies across a wide range of established rodent models of autism to mimic the wide range of aetiologies in the human population. A search was conducted in the PubMed and Web of Science databases to find primary research articles in mouse or rat models of autism which investigate central auditory processing. A total of 88 studies were included. These used non-invasive measures of auditory function, such as auditory brainstem response recordings, cortical event-related potentials, electroencephalography, and behavioural tests, which are translatable to human studies. They also included invasive measures, such as electrophysiology and histology, which shed insight on the origins of the phenotypes found in the non-invasive studies. The most consistent results across these studies were increased latency of the N1 peak of event-related potentials, decreased power and coherence of gamma activity in the auditory cortex, and increased auditory startle responses to high sound levels. Invasive studies indicated loss of subcortical inhibitory neurons, hyperactivity in the lateral superior olive and auditory thalamus, and reduced specificity of responses in the auditory cortex. This review compares the auditory phenotypes across rodent models and highlights those that mimic findings in human studies, providing a framework and avenues for future studies to inform understanding of the auditory system in autism.
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Affiliation(s)
- Maya Wilde
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Lena Constantin
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Peter R Thorne
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Section of Audiology, School of Population Health, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Ethan K Scott
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.,Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Juliette E Cheyne
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand.
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15
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Exploration of group II metabotropic glutamate receptor modulation in mouse models of Rett syndrome and MECP2 Duplication syndrome. Neuropharmacology 2022; 209:109022. [PMID: 35248529 PMCID: PMC8973998 DOI: 10.1016/j.neuropharm.2022.109022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/11/2022] [Accepted: 02/27/2022] [Indexed: 01/01/2023]
Abstract
Rett syndrome (RTT) and MECP2 Duplication syndrome (MDS) have opposing molecular origins in relation to expression and function of the transcriptional regulator Methyl-CpG-binding protein 2 (MeCP2). Several clinical and preclinical phenotypes, however, are shared between these disorders. Modulation of MeCP2 levels has recently emerged as a potential treatment option for both of these diseases. However, toxicity concerns remain with these approaches. Here, we focus on pharmacologically modulating the group II metabotropic glutamate receptors (mGlu), mGlu2 and mGlu3, which are two downstream targets of MeCP2 that are bidirectionally affected in expression in RTT patients and mice (Mecp2Null/+) versus an MDS mouse model (MECP2Tg1/o). Mecp2Null/+ and MECP2Tg1/o animals also exhibit contrasting phenotypes in trace fear acquisition, a form of temporal associative learning and memory, with trace fear deficiency observed in Mecp2Null/+ mice and abnormally enhanced trace fear acquisition in MECP2Tg1/o animals. In Mecp2Null/+ mice, treatment with the mGlu2/3 agonist LY379268 reverses the deficit in trace fear acquisition, and mGlu2/3 antagonism with LY341495 normalizes the abnormal trace fear learning and memory phenotype in MECP2Tg1/o mice. Altogether, these data highlight the role of group II mGlu receptors in RTT and MDS and demonstrate that both mGlu2 and mGlu3 may be potential therapeutic targets for these disorders.
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16
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MeCP2 and transcriptional control of eukaryotic gene expression. Eur J Cell Biol 2022; 101:151237. [DOI: 10.1016/j.ejcb.2022.151237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/30/2022] [Accepted: 05/09/2022] [Indexed: 11/19/2022] Open
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17
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Electrophysiological and Behavioral Evidence for Hyper- and Hyposensitivity in Rare Genetic Syndromes Associated with Autism. Genes (Basel) 2022; 13:genes13040671. [PMID: 35456477 PMCID: PMC9027402 DOI: 10.3390/genes13040671] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/29/2022] [Accepted: 04/05/2022] [Indexed: 01/27/2023] Open
Abstract
Our study reviewed abnormalities in spontaneous, as well as event-related, brain activity in syndromes with a known genetic underpinning that are associated with autistic symptomatology. Based on behavioral and neurophysiological evidence, we tentatively subdivided the syndromes on primarily hyper-sensitive (Fragile X, Angelman) and hypo-sensitive (Phelan–McDermid, Rett, Tuberous Sclerosis, Neurofibromatosis 1), pointing to the way of segregation of heterogeneous idiopathic ASD, that includes both hyper-sensitive and hypo-sensitive individuals. This segmentation links abnormalities in different genes, such as FMR1, UBE3A, GABRB3, GABRA5, GABRG3, SHANK3, MECP2, TSC1, TSC2, and NF1, that are causative to the above-mentioned syndromes and associated with synaptic transmission and cell growth, as well as with translational and transcriptional regulation and with sensory sensitivity. Excitation/inhibition imbalance related to GABAergic signaling, and the interplay of tonic and phasic inhibition in different brain regions might underlie this relationship. However, more research is needed. As most genetic syndromes are very rare, future investigations in this field will benefit from multi-site collaboration with a common protocol for electrophysiological and event-related potential (EEG/ERP) research that should include an investigation into all modalities and stages of sensory processing, as well as potential biomarkers of GABAergic signaling (such as 40-Hz ASSR).
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Improving clinical trial readiness to accelerate development of new therapeutics for Rett syndrome. Orphanet J Rare Dis 2022; 17:108. [PMID: 35246185 PMCID: PMC8894842 DOI: 10.1186/s13023-022-02240-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 02/06/2022] [Indexed: 12/16/2022] Open
Abstract
Rett syndrome is associated with severe functional impairments and many comorbidities, each in urgent need of treatments. Mutations in the MECP2 gene were identified as causing Rett syndrome in 1999. Over the past 20 years there has been an abundance of preclinical research with some studies leading to human clinical trials. Despite this, few viable therapeutic options have emerged from this investment of effort. Reasons for this lack of success as they relate both to preclinical research and the clinical trial landscape are discussed. Considering what needs to be done to promote further success in the field, we take a positive and constructive approach and introduce the concept of clinical trial readiness and its necessary ingredients for Rett syndrome. These include: listening to the needs of families; support from advocacy groups; optimising use of existing clinic infrastructures and available natural history data; and, finally, the validation of existing outcome measures and/or the development and validation of new measures. We conclude by reiterating the need for a collaborative and coordinated approach amongst the many different stakeholder groups and the need to engage in new types of trial design which could be much more efficient, less costly and much less burdensome on families.
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19
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Guo Y, Guan Y, Zhu H, Sun T, Wang Y, Huang Y, Ma C, Emery R, Guan W, Wang C, Liu C. Therapeutic function of iPSCs-derived primitive neuroepithelial cells in a rat model of Parkinson's disease. Neurochem Int 2022; 155:105324. [PMID: 35247479 DOI: 10.1016/j.neuint.2022.105324] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 02/15/2022] [Accepted: 02/27/2022] [Indexed: 11/16/2022]
Abstract
Induced pluripotent stem cells (iPSCs) are a promising unlimited source for cell replacement therapy of neurodegenerative disorders, including Parkinson's disease (PD). In the present study, rat iPSCs-derived primitive neuroepithelial cells (RiPSCs-iNECs) were successfully induced from rat iPSCs (RiPSCs) following two major developmental stages, and could generate neurospheres and differentiated into both neurons and astrocytes in vitro. Then, the RiPSCs-iNECs-GFP+ were unilaterally transplanted into the right substantia nigra (SN) of 6-hydroxydopamine-lesioned rat models of PD. The results demonstrated that the grafted RiPSCs-iNECs could survive in parkinsonian rat brain for at least 150 days, and many of them differentiated into tyrosine hydroxylase (TH)-positive cells. Furthermore, the PD model rats grafted with RiPSCs-iNECs exhibited a significant functional recovery from their parkinsonian behavioral defects. Histological studies showed that RiPSCs-iNECs could differentiate into multiple types of neurons including dopaminergic neurons, GFAP, Pax6, FoxA2 and DAT-positive cells, and induced dopaminergic neurons extended dense neurites into the host striatum. Thus, iPSCs derived primitive neuroepithelial cells could be an attractive candidate as a source of donor material for the treatment of PD, but the molecular mechanism needs further clarification.
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Affiliation(s)
- Yu Guo
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China
| | - Yuhan Guan
- University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Huan Zhu
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China
| | - Tingting Sun
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China
| | - Yuanyuan Wang
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China
| | - Yuqi Huang
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China
| | - Caiyun Ma
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China; Institute of Beijing Animal Science and Veterinary, Chinese Academy of Agricultural Science, Beijing, 100193, China
| | - Rik Emery
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Weijun Guan
- Institute of Beijing Animal Science and Veterinary, Chinese Academy of Agricultural Science, Beijing, 100193, China
| | - Chunjing Wang
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China.
| | - Changqing Liu
- School of Laboratory Medicine, School of Life Sciences, Bengbu Medical College, Bengbu, 233000, China; Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, 06030, USA.
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20
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Disruption of MeCP2-TCF20 complex underlies distinct neurodevelopmental disorders. Proc Natl Acad Sci U S A 2022; 119:2119078119. [PMID: 35074918 PMCID: PMC8794850 DOI: 10.1073/pnas.2119078119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 12/16/2022] Open
Abstract
MeCP2 is associated with Rett syndrome (RTT), MECP2 duplication syndrome, and a number of conditions with isolated features of these diseases, including autism, intellectual disability, and motor dysfunction. MeCP2 is known to broadly bind methylated DNA, but the precise molecular mechanism driving disease pathogenesis remains to be determined. Using proximity-dependent biotinylation (BioID), we identified a transcription factor 20 (TCF20) complex that interacts with MeCP2 at the chromatin interface. Importantly, RTT-causing mutations in MECP2 disrupt this interaction. TCF20 and MeCP2 are highly coexpressed in neurons and coregulate the expression of key neuronal genes. Reducing Tcf20 partially rescued the behavioral deficits caused by MECP2 overexpression, demonstrating a functional relationship between MeCP2 and TCF20 in MECP2 duplication syndrome pathogenesis. We identified a patient exhibiting RTT-like neurological features with a missense mutation in the PHF14 subunit of the TCF20 complex that abolishes the MeCP2-PHF14-TCF20 interaction. Our data demonstrate the critical role of the MeCP2-TCF20 complex for brain function.
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21
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Collins BE, Neul JL. Rett Syndrome and MECP2 Duplication Syndrome: Disorders of MeCP2 Dosage. Neuropsychiatr Dis Treat 2022; 18:2813-2835. [PMID: 36471747 PMCID: PMC9719276 DOI: 10.2147/ndt.s371483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/14/2022] [Indexed: 11/30/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused predominantly by loss-of-function mutations in the gene Methyl-CpG-binding protein 2 (MECP2), which encodes the MeCP2 protein. RTT is a MECP2-related disorder, along with MECP2 duplication syndrome (MDS), caused by gain-of-function duplications of MECP2. Nearly two decades of research have advanced our knowledge of MeCP2 function in health and disease. The following review will discuss MeCP2 protein function and its dysregulation in the MECP2-related disorders RTT and MDS. This will include a discussion of the genetic underpinnings of these disorders, specifically how sporadic X-chromosome mutations arise and manifest in specific populations. We will then review current diagnostic guidelines and clinical manifestations of RTT and MDS. Next, we will delve into MeCP2 biology, describing the dual landscapes of methylated DNA and its reader MeCP2 across the neuronal genome as well as the function of MeCP2 as a transcriptional modulator. Following this, we will outline common MECP2 mutations and genotype-phenotype correlations in both diseases, with particular focus on mutations associated with relatively mild disease in RTT. We will also summarize decades of disease modeling and resulting molecular, synaptic, and behavioral phenotypes associated with RTT and MDS. Finally, we list several therapeutics in the development pipeline for RTT and MDS and available evidence of their safety and efficacy.
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Affiliation(s)
- Bridget E Collins
- Medical Scientist Training Program, Vanderbilt University, Nashville, TN, USA
| | - Jeffrey L Neul
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special Education, Vanderbilt University Medical Center and Vanderbilt University, Nashville, TN, USA
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22
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Terzic B, Davatolhagh MF, Ho Y, Tang S, Liu YT, Xia Z, Cui Y, Fuccillo MV, Zhou Z. Temporal manipulation of Cdkl5 reveals essential postdevelopmental functions and reversible CDKL5 deficiency disorder-related deficits. J Clin Invest 2021; 131:143655. [PMID: 34651584 DOI: 10.1172/jci143655] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 08/05/2021] [Indexed: 12/23/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is an early onset, neurodevelopmental syndrome associated with pathogenic variants in the X-linked gene encoding cyclin-dependent kinase-like 5 (CDKL5). CDKL5 has been implicated in neuronal synapse maturation, yet its postdevelopmental necessity and the reversibility of CDD-associated impairments remain unknown. We temporally manipulated endogenous Cdkl5 expression in male mice and found that postdevelopmental loss of CDKL5 disrupts numerous behavioral domains, hippocampal circuit communication, and dendritic spine morphology, demonstrating an indispensable role for CDKL5 in the adult brain. Accordingly, restoration of Cdkl5 after the early stages of brain development using a conditional rescue mouse model ameliorated CDD-related behavioral impairments and aberrant NMDA receptor signaling. These findings highlight the requirement of CDKL5 beyond early development, underscore the potential for disease reversal in CDD, and suggest that a broad therapeutic time window exists for potential treatment of CDD-related deficits.
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Affiliation(s)
| | - M Felicia Davatolhagh
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | - Marc V Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Mao Y, Evans EE, Mishra V, Balch L, Eberhardt A, Zauderer M, Gold WA. Anti-Semaphorin 4D Rescues Motor, Cognitive, and Respiratory Phenotypes in a Rett Syndrome Mouse Model. Int J Mol Sci 2021; 22:ijms22179465. [PMID: 34502373 PMCID: PMC8431088 DOI: 10.3390/ijms22179465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 01/09/2023] Open
Abstract
Rett syndrome is a neurodevelopmental disorder caused by mutations of the methyl-CpG binding protein 2 gene. Abnormal physiological functions of glial cells contribute to pathogenesis of Rett syndrome. Semaphorin 4D (SEMA4D) regulates processes central to neuroinflammation and neurodegeneration including cytoskeletal structures required for process extension, communication, and migration of glial cells. Blocking SEMA4D-induced gliosis may preserve normal glial and neuronal function and rescue neurological dysfunction in Rett syndrome. We evaluated the pre-clinical therapeutic efficacy of an anti-SEMA4D monoclonal antibody in the Rett syndrome Mecp2T158A transgenic mouse model and investigated the contribution of glial cells as a proposed mechanism of action in treated mice and in primary glial cultures isolated from Mecp2T158A/y mutant mice. SEMA4D is upregulated in neurons while glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1-positive cells are upregulated in Mecp2T158A/y mice. Anti-SEMA4D treatment ameliorates Rett syndrome-specific symptoms and improves behavioural functions in both pre-symptomatic and symptomatic cohorts of hemizygous Mecp2T158A/y male mice. Anti-SEMA4D also reduces astrocyte and microglia activation in vivo. In vitro experiments demonstrate an abnormal cytoskeletal structure in mutant astrocytes in the presence of SEMA4D, while anti-SEMA4D antibody treatment blocks SEMA4D–Plexin B1 signaling and mitigates these abnormalities. These results suggest that anti-SEMA4D immunotherapy may be an effective treatment option to alleviate symptoms and improve cognitive and motor function in Rett syndrome.
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Affiliation(s)
- Yilin Mao
- Molecular Neurobiology Research Laboratory, Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Westmead, NSW 2145, Australia;
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Elizabeth E. Evans
- Vaccinex Inc., Rochester, NY 14620, USA; (E.E.E.); (V.M.); (L.B.); (A.E.); (M.Z.)
| | - Vikas Mishra
- Vaccinex Inc., Rochester, NY 14620, USA; (E.E.E.); (V.M.); (L.B.); (A.E.); (M.Z.)
| | - Leslie Balch
- Vaccinex Inc., Rochester, NY 14620, USA; (E.E.E.); (V.M.); (L.B.); (A.E.); (M.Z.)
| | - Allison Eberhardt
- Vaccinex Inc., Rochester, NY 14620, USA; (E.E.E.); (V.M.); (L.B.); (A.E.); (M.Z.)
| | - Maurice Zauderer
- Vaccinex Inc., Rochester, NY 14620, USA; (E.E.E.); (V.M.); (L.B.); (A.E.); (M.Z.)
| | - Wendy A. Gold
- Molecular Neurobiology Research Laboratory, Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Westmead, NSW 2145, Australia;
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
- Molecular Neurobiology Research Laboratory, The Children’s Medical Research Institute, Westmead, NSW 2145, Australia
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
- Correspondence:
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24
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Ahadullah, Yau SY, Lu HX, Lee TMC, Guo H, Chan CCH. PM 2.5 as a potential risk factor for autism spectrum disorder: Its possible link to neuroinflammation, oxidative stress and changes in gene expression. Neurosci Biobehav Rev 2021; 128:534-548. [PMID: 34216652 DOI: 10.1016/j.neubiorev.2021.06.043] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/10/2021] [Accepted: 06/29/2021] [Indexed: 10/21/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by behavioral deficits including impairments in social communication, social interaction, and repetitive behaviors. Because the etiology of ASD is still largely unknown, there is no cure for ASD thus far. Although it has been established that genetic components play a vital role in ASD development, the influence of epigenetic regulation induced by environmental factors could also contribute to ASD susceptibility. Accumulated evidence has suggested that exposure to atmospheric particulate matter (PM) in polluted air could affect neurodevelopment, thus possibly leading to ASD. Particles with a size of 2.5 μm (PM2.5) or less have been shown to have negative effects on human health, and could be linked to ASD symptoms in children. This review summarizes evidence from clinical and animal studies to demonstrate the possible linkage between PM2.5 exposure and the incidence of ASD in children. An attempt was made to explore the possible mechanisms of this linkage, including changes of gene expression, oxidative stress and neuroinflammation induced by PM2.5 exposure.
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Affiliation(s)
- Ahadullah
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, China
| | - Suk-Yu Yau
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, China; Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou 510515, China.
| | - Hao-Xian Lu
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Tatia M C Lee
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology and Human Neuroscience, The University of Hong Kong, Hong Kong, China
| | - Hai Guo
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China.
| | - Chetwyn C H Chan
- Department of Psychology, The Education University of Hong Kong, Tai Po, Hong Kong, China
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25
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Abstract
A motif of dinucleotide repeats in the genome may be associated with Rett syndrome
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Affiliation(s)
- Jian Zhou
- Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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26
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Campanella S. Use of cognitive event-related potentials in the management of psychiatric disorders: Towards an individual follow-up and multi-component clinical approach. World J Psychiatry 2021; 11:153-168. [PMID: 34046312 PMCID: PMC8134870 DOI: 10.5498/wjp.v11.i5.153] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/05/2021] [Accepted: 04/14/2021] [Indexed: 02/06/2023] Open
Abstract
Relapse prevention remains a major challenge in psychiatry, thus indicating that the established treatment methods combining psychotherapy with neuropharmacological interventions are not entirely effective. In recent years, several intervention strategies have been devised that are aimed at improving psychiatric treatment by providing a complementary set of add-on tools that can be used by clinicians to improve current patient assessment. Among these, cognitive event-related potentials (ERPs) have been indexed as valuable biomarkers of the pathophysiological mechanisms of various mental illnesses. However, despite decades of research, their clinical utility is still controversial and a matter of debate. In this opinion review, I present the main arguments supporting the use of cognitive ERPs in the management of psychiatric disorders, stressing why it is currently still not the case despite the vast number of ERP studies to date. I also propose a clinically-oriented suitable way in which this technique could — in my opinion — be effectively incorporated into individual patient care by promotion of the use of individual ERP test-retest sessions and the use of a multi-component approach.
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Affiliation(s)
- Salvatore Campanella
- Laboratoire de Psychologie Médicale et d’Addictologie, ULB Neuroscience Institute (UNI), CHU Brugmann-Université Libre de Bruxelles (U.L.B.), Brussels 1020, Belgium
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27
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Reviewing Evidence for the Relationship of EEG Abnormalities and RTT Phenotype Paralleled by Insights from Animal Studies. Int J Mol Sci 2021; 22:ijms22105308. [PMID: 34069993 PMCID: PMC8157853 DOI: 10.3390/ijms22105308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/09/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder that is usually caused by mutations of the MECP2 gene. Patients with RTT suffer from severe deficits in motor, perceptual and cognitive domains. Electroencephalogram (EEG) has provided useful information to clinicians and scientists, from the very first descriptions of RTT, and yet no reliable neurophysiological biomarkers related to the pathophysiology of the disorder or symptom severity have been identified to date. To identify consistently observed and potentially informative EEG characteristics of RTT pathophysiology, and ascertain areas most worthy of further systematic investigation, here we review the literature for EEG abnormalities reported in patients with RTT and in its disease models. While pointing to some promising potential EEG biomarkers of RTT, our review identify areas of need to realize the potential of EEG including (1) quantitative investigation of promising clinical-EEG observations in RTT, e.g., shift of mu rhythm frequency and EEG during sleep; (2) closer alignment of approaches between patients with RTT and its animal models to strengthen the translational significance of the work (e.g., EEG measurements and behavioral states); (3) establishment of large-scale consortium research, to provide adequate Ns to investigate age and genotype effects.
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28
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Sinnamon JR, Kim SY, Fisk JR, Song Z, Nakai H, Jeng S, McWeeney SK, Mandel G. In Vivo Repair of a Protein Underlying a Neurological Disorder by Programmable RNA Editing. Cell Rep 2021; 32:107878. [PMID: 32668243 PMCID: PMC7449137 DOI: 10.1016/j.celrep.2020.107878] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/08/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023] Open
Abstract
Programmable RNA editing is gaining momentum as an approach to repair mutations, but its efficiency in repairing endogenous mutant RNA in complex tissue is unknown. Here we apply this approach to the brain and successfully repair a guanosine-to-adenosine mutation in methyl CpG binding protein 2 RNA that causes the neurodevelopmental disease Rett syndrome. Repair is mediated by hippocampal injections of juvenile Mecp2317G>A mice with an adeno-associated virus expressing the hyperactive catalytic domain of adenosine deaminase acting on RNA 2 and Mecp2 guide. After 1 month, 50% of Mecp2 RNA is recoded in three different hippocampal neuronal populations. MeCP2 protein localization to heterochromatin is restored in neurons to 50% of wild-type levels. Whole-transcriptome RNA analysis of one neuronal population indicates that the majority of off-target editing sites exhibit rates of 30% or less. This study demonstrates that programmable RNA editing can be utilized to repair mutations in mouse models of neurological disease. Sinnamon et al. show that the Mecp2 guide-targeted “editase,” introduced by an adeno-associated virus into the hippocampus of a Rett syndrome mouse model, repairs a large fraction of pathological Mecp2G>A RNA. MeCP2 function, visualized by chromatin association in neurons, is repaired to similar levels. The results point toward a potential therapy for Rett syndrome.
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Affiliation(s)
- John R Sinnamon
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Susan Y Kim
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jenna R Fisk
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Zhen Song
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR 97239, USA
| | - Hiroyuki Nakai
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR 97239, USA
| | - Sophia Jeng
- Division of Bioinformatics and Computational Biology, Department of Medical Informatics and Clinical Epidemiology, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Shannon K McWeeney
- Division of Bioinformatics and Computational Biology, Department of Medical Informatics and Clinical Epidemiology, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Gail Mandel
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA.
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29
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Sharifi O, Yasui DH. The Molecular Functions of MeCP2 in Rett Syndrome Pathology. Front Genet 2021; 12:624290. [PMID: 33968128 PMCID: PMC8102816 DOI: 10.3389/fgene.2021.624290] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/08/2021] [Indexed: 12/13/2022] Open
Abstract
MeCP2 protein, encoded by the MECP2 gene, binds to DNA and affects transcription. Outside of this activity the true range of MeCP2 function is still not entirely clear. As MECP2 gene mutations cause the neurodevelopmental disorder Rett syndrome in 1 in 10,000 female births, much of what is known about the biologic function of MeCP2 comes from studying human cell culture models and rodent models with Mecp2 gene mutations. In this review, the full scope of MeCP2 research available in the NIH Pubmed (https://pubmed.ncbi.nlm.nih.gov/) data base to date is considered. While not all original research can be mentioned due to space limitations, the main aspects of MeCP2 and Rett syndrome research are discussed while highlighting the work of individual researchers and research groups. First, the primary functions of MeCP2 relevant to Rett syndrome are summarized and explored. Second, the conflicting evidence and controversies surrounding emerging aspects of MeCP2 biology are examined. Next, the most obvious gaps in MeCP2 research studies are noted. Finally, the most recent discoveries in MeCP2 and Rett syndrome research are explored with a focus on the potential and pitfalls of novel treatments and therapies.
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Affiliation(s)
- Osman Sharifi
- LaSalle Laboratory, Department of Medical Microbiology and Immunology, UC Davis School of Medicine, Davis, CA, United States
| | - Dag H Yasui
- LaSalle Laboratory, Department of Medical Microbiology and Immunology, UC Davis School of Medicine, Davis, CA, United States
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30
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Haq SU, Bhat UA, Kumar A. Prenatal stress effects on offspring brain and behavior: Mediators, alterations and dysregulated epigenetic mechanisms. J Biosci 2021. [DOI: 10.1007/s12038-021-00153-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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31
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Saby JN, Benke TA, Peters SU, Standridge SM, Matsuzaki J, Cutri-French C, Swanson LC, Lieberman DN, Key AP, Percy AK, Neul JL, Nelson CA, Roberts TP, Marsh ED. Multisite Study of Evoked Potentials in Rett Syndrome. Ann Neurol 2021; 89:790-802. [PMID: 33480039 PMCID: PMC8882338 DOI: 10.1002/ana.26029] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 01/04/2023]
Abstract
OBJECTIVE The aim of the current study was to evaluate the utility of evoked potentials as a biomarker of cortical function in Rett syndrome (RTT). As a number of disease-modifying therapeutics are currently under development, there is a pressing need for biomarkers to objectively and precisely assess the effectiveness of these treatments. METHOD Yearly visual evoked potentials (VEPs) and auditory evoked potentials (AEPs) were acquired from individuals with RTT, aged 2 to 37 years, and control participants across 5 sites as part of the Rett Syndrome and Related Disorders Natural History Study. Baseline and year 1 data, when available, were analyzed and the repeatability of the results was tested. Two syndrome-specific measures from the Natural History Study were used for evaluating the clinical relevance of the VEP and AEP parameters. RESULTS At the baseline study, group level comparisons revealed reduced VEP and AEP amplitude in RTT compared to control participants. Further analyses within the RTT group indicated that this reduction was associated with RTT-related symptoms, with greater severity associated with lower VEP and AEP amplitude. In participants with RTT, VEP and AEP amplitude was also negatively associated with age. Year 1 follow-up data analyses yielded similar findings and evidence of repeatability of EPs at the individual level. INTERPRETATION The present findings indicate the promise of evoked potentials (EPs) as an objective measure of disease severity in individuals with RTT. Our multisite approach demonstrates potential research and clinical applications to provide unbiased assessment of disease staging, prognosis, and response to therapy. ANN NEUROL 2021;89:790-802.
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Affiliation(s)
- Joni N. Saby
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Timothy A. Benke
- Department of Pediatrics, Neurology, Pharmacology and Otolaryngology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, Colorado
| | - Sarika U. Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, Tennessee
| | - Shannon M. Standridge
- Cincinnati Children’s Hospital Medical Center, Division of Neurology and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Junko Matsuzaki
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Clare Cutri-French
- Division of Child Neurology, Children’s Hospital of Philadelphia, Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Lindsay C. Swanson
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
| | - David N. Lieberman
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
| | - Alexandra P. Key
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, Tennessee
| | - Alan K. Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jeffrey L. Neul
- Department of Pediatrics, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, Tennessee
| | - Charles A. Nelson
- Laboratories of Cognitive Neuroscience, Boston Children’s Hospital, Boston, Massachusetts; Department of Pediatrics, Harvard Medical School
| | - Timothy P.L. Roberts
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Eric D. Marsh
- Division of Child Neurology, Children’s Hospital of Philadelphia, Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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32
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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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Tillotson R, Cholewa-Waclaw J, Chhatbar K, Connelly JC, Kirschner SA, Webb S, Koerner MV, Selfridge J, Kelly DA, De Sousa D, Brown K, Lyst MJ, Kriaucionis S, Bird A. Neuronal non-CG methylation is an essential target for MeCP2 function. Mol Cell 2021; 81:1260-1275.e12. [PMID: 33561390 PMCID: PMC7980222 DOI: 10.1016/j.molcel.2021.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/17/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
DNA methylation is implicated in neuronal biology via the protein MeCP2, the mutation of which causes Rett syndrome. MeCP2 recruits the NCOR1/2 co-repressor complexes to methylated cytosine in the CG dinucleotide, but also to sites of non-CG methylation, which are abundant in neurons. To test the biological significance of the dual-binding specificity of MeCP2, we replaced its DNA binding domain with an orthologous domain from MBD2, which can only bind mCG motifs. Knockin mice expressing the domain-swap protein displayed severe Rett-syndrome-like phenotypes, indicating that normal brain function requires the interaction of MeCP2 with sites of non-CG methylation, specifically mCAC. The results support the notion that the delayed onset of Rett syndrome is due to the simultaneous post-natal accumulation of mCAC and its reader MeCP2. Intriguingly, genes dysregulated in both Mecp2 null and domain-swap mice are implicated in other neurological disorders, potentially highlighting targets of relevance to the Rett syndrome phenotype.
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Affiliation(s)
- Rebekah Tillotson
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Justyna Cholewa-Waclaw
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kashyap Chhatbar
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - John C Connelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Sophie A Kirschner
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Martha V Koerner
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Jim Selfridge
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - David A Kelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Dina De Sousa
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kyla Brown
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Matthew J Lyst
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Skirmantas Kriaucionis
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK.
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Scrutinizing the molecular, biochemical, and cytogenetic attributes in subjects with Rett syndrome (RTT) and their mothers. Epilepsy Behav 2020; 111:107277. [PMID: 32653844 DOI: 10.1016/j.yebeh.2020.107277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 11/21/2022]
Abstract
Rett syndrome (RTT) is a stern dominant progressive neurological development disorder linked with X chromosome ranking second for mental slowdown, exclusively in females after few months of birth with normal development and growth period. Genetically any defects in universally expressed methyl-CpG binding protein 2 (MeCP2) transcription regulator gene are considered as radix for RTT in almost all the previous studies. Our study mainly focuses in unraveling the genetic alterations like identifying MeCP2 gene polymorphisms, chromosomal abnormalities, or X-chromosome inactivation (XCI) as underlying cause of RTT in prototypes sorted through Diagnostic and Statistical Manual of Mental Disorders-Text Revised (DSM IV). In addition, we have examined the probable surrogates of brain function disabilities like serotonin, homocysteine (Hcy), calcium, potassium, and lead from blood in both RTT porotypes and their mothers. In our investigation, we have observed varied amino acid substitution of MeCP2 and varied frequency of skewed XCI in RTT prototype. Our study validates that the demonstration of chromosomal analysis, biochemical analysis, and genomic observations helps in concluding RTT condition and can be helpful in providing appropriate treatment and counseling as well as improve the currently available protocol of diagnosis.
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35
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Adcock KS, Blount AE, Morrison RA, Alvarez-Dieppa A, Kilgard MP, Engineer CT, Hays SA. Deficits in skilled motor and auditory learning in a rat model of Rett syndrome. J Neurodev Disord 2020; 12:27. [PMID: 32988374 PMCID: PMC7523346 DOI: 10.1186/s11689-020-09330-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/18/2020] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Rett syndrome is an X-linked neurodevelopmental disorder caused by a mutation in the gene MECP2. Individuals with Rett syndrome display developmental regression at an early age, and develop a range of motor, auditory, cognitive, and social impairments. Several studies have successfully modeled some aspects of dysfunction and Rett syndrome-like phenotypes in transgenic mouse and rat models bearing mutations in the MECP2 gene. Here, we sought to extend these findings and characterize skilled learning, a more complex behavior known to be altered in Rett syndrome. METHODS We evaluated the acquisition and performance of auditory and motor function on two complex tasks in heterozygous female Mecp2 rats. Animals were trained to perform a speech discrimination task or a skilled forelimb reaching task. RESULTS Our results reveal that Mecp2 rats display slower acquisition and reduced performance on an auditory discrimination task than wild-type (WT) littermates. Similarly, Mecp2 rats exhibit impaired learning rates and worse performance on a skilled forelimb motor task compared to WT. CONCLUSIONS Together, these findings illustrate novel deficits in skilled learning consistent with clinical manifestation of Rett syndrome and provide a framework for development of therapeutic strategies to improve these complex behaviors.
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Affiliation(s)
- Katherine S Adcock
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA.
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA.
| | - Abigail E Blount
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Robert A Morrison
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Amanda Alvarez-Dieppa
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Michael P Kilgard
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Crystal T Engineer
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Seth A Hays
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
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Turner TJ, Zourray C, Schorge S, Lignani G. Recent advances in gene therapy for neurodevelopmental disorders with epilepsy. J Neurochem 2020; 157:229-262. [PMID: 32880951 PMCID: PMC8436749 DOI: 10.1111/jnc.15168] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/14/2022]
Abstract
Neurodevelopmental disorders can be caused by mutations in neuronal genes fundamental to brain development. These disorders have severe symptoms ranging from intellectually disability, social and cognitive impairments, and a subset are strongly linked with epilepsy. In this review, we focus on those neurodevelopmental disorders that are frequently characterized by the presence of epilepsy (NDD + E). We loosely group the genes linked to NDD + E with different neuronal functions: transcriptional regulation, intrinsic excitability and synaptic transmission. All these genes have in common a pivotal role in defining the brain architecture and function during early development, and when their function is altered, symptoms can present in the first stages of human life. The relationship with epilepsy is complex. In some NDD + E, epilepsy is a comorbidity and in others seizures appear to be the main cause of the pathology, suggesting that either structural changes (NDD) or neuronal communication (E) can lead to these disorders. Furthermore, grouping the genes that cause NDD + E, we review the uses and limitations of current models of the different disorders, and how different gene therapy strategies are being developed to treat them. We highlight where gene replacement may not be a treatment option, and where innovative therapeutic tools, such as CRISPR‐based gene editing, and new avenues of delivery are required. In general this group of genetically defined disorders, supported increasing knowledge of the mechanisms leading to neurological dysfunction serve as an excellent collection for illustrating the translational potential of gene therapy, including newly emerging tools.
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Affiliation(s)
- Thomas J Turner
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Clara Zourray
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Department of Pharmacology, UCL School of Pharmacy, London, UK
| | | | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
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Pappalardo JL, Zhang L, Pecsok MK, Perlman K, Zografou C, Raddassi K, Abulaban A, Krishnaswamy S, Antel J, van Dijk D, Hafler DA. Transcriptomic and clonal characterization of T cells in the human central nervous system. Sci Immunol 2020; 5:eabb8786. [PMID: 32948672 PMCID: PMC8567322 DOI: 10.1126/sciimmunol.abb8786] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 08/26/2020] [Indexed: 08/04/2023]
Abstract
T cells provide critical immune surveillance to the central nervous system (CNS), and the cerebrospinal fluid (CSF) is thought to be a main route for their entry. Further characterization of the state of T cells in the CSF in healthy individuals is important for understanding how T cells provide protective immune surveillance without damaging the delicate environment of the CNS and providing tissue-specific context for understanding immune dysfunction in neuroinflammatory disease. Here, we have profiled T cells in the CSF of healthy human donors and have identified signatures related to cytotoxic capacity and tissue adaptation that are further exemplified in clonally expanded CSF T cells. By comparing profiles of clonally expanded T cells obtained from the CSF of patients with multiple sclerosis (MS) and healthy donors, we report that clonally expanded T cells from the CSF of patients with MS have heightened expression of genes related to T cell activation and cytotoxicity.
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Affiliation(s)
- Jenna L Pappalardo
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Le Zhang
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Maggie K Pecsok
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Kelly Perlman
- Montreal Neurologic Institute, Montreal, Quebec, Canada
| | - Chrysoula Zografou
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Khadir Raddassi
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Ahmad Abulaban
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Smita Krishnaswamy
- Departments of Genetics and Computer Science, Yale School of Medicine, New Haven, CT 06511, USA
| | - Jack Antel
- Montreal Neurologic Institute, Montreal, Quebec, Canada
| | - David van Dijk
- Departments of Internal Medicine (Cardiology), Cardiovascular Research Center, and Computer Science, New Haven, CT 06511, USA.
| | - David A Hafler
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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Dong HW, Erickson K, Lee JR, Merritt J, Fu C, Neul JL. Detection of neurophysiological features in female R255X MeCP2 mutation mice. Neurobiol Dis 2020; 145:105083. [PMID: 32927061 PMCID: PMC7572861 DOI: 10.1016/j.nbd.2020.105083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/11/2020] [Accepted: 09/08/2020] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder (NDD) that is nearly always caused by loss of function mutations in Methyl-CpG-binding Protein 2 (MECP2) and shares many clinical features with other NDD. Genetic restoration of Mecp2 in symptomatic mice lacking MeCP2 expression can reverse symptoms, providing hope that disease modifying therapies can be identified for RTT. Effective and rapid clinical trial completion relies on well-defined clinical outcome measures and robust biomarkers of treatment responses. Studies on other NDD have found evidence of differences in neurophysiological measures that correlate with disease severity. However, currently there are no well-validated biomarkers in RTT to predict disease prognosis or treatment responses. To address this, we characterized neurophysiological features in a mouse model of RTT containing a knock-in nonsense mutation (p.R255X) in the Mecp2 locus. We found a variety of changes in heterozygous female Mecp2R255X/X mice including age-related changes in sleep/wake architecture, alterations in baseline EEG power, increased incidence of spontaneous epileptiform discharges, and changes in auditory evoked potentials. Furthermore, we identified association of some neurophysiological features with disease severity. These findings provide a set of potential non-invasive and translatable biomarkers that can be utilized in preclinical therapy trials in animal models of RTT and eventually within the context of clinical trials.
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Affiliation(s)
- Hong-Wei Dong
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Kirsty Erickson
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jessica R Lee
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jonathan Merritt
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Cary Fu
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jeffrey L Neul
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
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Byiers BJ, Payen A, Feyma T, Panoskaltsis-Mortari A, Ehrhardt MJ, Symons FJ. Associations Among Diurnal Salivary Cortisol Patterns, Medication Use, and Behavioral Phenotype Features in a Community Sample of Rett Syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2020; 125:353-368. [PMID: 32936892 PMCID: PMC10699094 DOI: 10.1352/1944-7558-125.5.353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 02/10/2020] [Indexed: 06/11/2023]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder resulting from mutations of the MECP2 gene. Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis and abnormal stress responses have been observed in animal models of RTT, but little is known about HPA axis function among individuals with RTT. Diurnal salivary cortisol patterns from 30 females with RTT were examined in relation to mutation type, medication use, and features of the RTT behavioral phenotype. Cortisol patterns were significantly related to mutation severity, anticonvulsant medication status, and bruxism (tooth grinding). This study provides preliminary support for the hypothesis that RTT may be at risk for outcomes associated with aberrant HPA axis function, and that this risk may be mediated by mutation type.
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Affiliation(s)
| | - Ameante Payen
- Breanne J. Byiers and Ameante Payen, University of Minnesota
| | - Timothy Feyma
- Timothy Feyma, Gillette Children's Specialty Healthcare, St. Paul, Minnesota
| | | | - Michael J Ehrhardt
- Angela Panoskaltsis-Mortari, Michael J. Ehrhardt, and Frank J. Symons, University of Minnesota
| | - Frank J Symons
- Angela Panoskaltsis-Mortari, Michael J. Ehrhardt, and Frank J. Symons, University of Minnesota
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Adcock KS, Chandler C, Buell EP, Solorzano BR, Loerwald KW, Borland MS, Engineer CT. Vagus nerve stimulation paired with tones restores auditory processing in a rat model of Rett syndrome. Brain Stimul 2020; 13:1494-1503. [PMID: 32800964 DOI: 10.1016/j.brs.2020.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/26/2020] [Accepted: 08/07/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Rett syndrome is a rare neurological disorder associated with a mutation in the X-linked gene MECP2. This disorder mainly affects females, who typically have seemingly normal early development followed by a regression of acquired skills. The rodent Mecp2 model exhibits many of the classic neural abnormalities and behavioral deficits observed in individuals with Rett syndrome. Similar to individuals with Rett syndrome, both auditory discrimination ability and auditory cortical responses are impaired in heterozygous Mecp2 rats. The development of therapies that can enhance plasticity in auditory networks and improve auditory processing has the potential to impact the lives of individuals with Rett syndrome. Evidence suggests that precisely timed vagus nerve stimulation (VNS) paired with sound presentation can drive robust neuroplasticity in auditory networks and enhance the benefits of auditory therapy. OBJECTIVE The aim of this study was to investigate the ability of VNS paired with tones to restore auditory processing in Mecp2 transgenic rats. METHODS Seventeen female heterozygous Mecp2 rats and 8 female wild-type (WT) littermates were used in this study. The rats were exposed to multiple tone frequencies paired with VNS 300 times per day for 20 days. Auditory cortex responses were then examined following VNS-tone pairing therapy or no therapy. RESULTS Our results indicate that Mecp2 mutation alters auditory cortex responses to sounds compared to WT controls. VNS-tone pairing in Mecp2 rats improves the cortical response strength to both tones and speech sounds compared to untreated Mecp2 rats. Additionally, VNS-tone pairing increased the information contained in the neural response that can be used to discriminate between different consonant sounds. CONCLUSION These results demonstrate that VNS-sound pairing may represent a strategy to enhance auditory function in individuals with Rett syndrome.
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Affiliation(s)
- Katherine S Adcock
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Collin Chandler
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Elizabeth P Buell
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Bleyda R Solorzano
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Kristofer W Loerwald
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Michael S Borland
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Crystal T Engineer
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA.
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41
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Automatic identification of curve shapes with applications to ultrasonic vocalization. Comput Stat Data Anal 2020. [DOI: 10.1016/j.csda.2020.106956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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42
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Kim T, Song B, Lee IS. Drosophila Glia: Models for Human Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2020; 21:E4859. [PMID: 32660023 PMCID: PMC7402321 DOI: 10.3390/ijms21144859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are key players in the proper formation and maintenance of the nervous system, thus contributing to neuronal health and disease in humans. However, little is known about the molecular pathways that govern glia-neuron communications in the diseased brain. Drosophila provides a useful in vivo model to explore the conserved molecular details of glial cell biology and their contributions to brain function and disease susceptibility. Herein, we review recent studies that explore glial functions in normal neuronal development, along with Drosophila models that seek to identify the pathological implications of glial defects in the context of various central nervous system disorders.
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Affiliation(s)
| | | | - Im-Soon Lee
- Department of Biological Sciences, Center for CHANS, Konkuk University, Seoul 05029, Korea; (T.K.); (B.S.)
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43
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Sysoeva OV, Molholm S, Djukic A, Frey HP, Foxe JJ. Atypical processing of tones and phonemes in Rett Syndrome as biomarkers of disease progression. Transl Psychiatry 2020; 10:188. [PMID: 32522978 PMCID: PMC7287060 DOI: 10.1038/s41398-020-00877-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 05/19/2020] [Accepted: 05/26/2020] [Indexed: 12/27/2022] Open
Abstract
Due to severe motor impairments and the lack of expressive language abilities seen in most patients with Rett Syndrome (RTT), it has proven extremely difficult to obtain accurate measures of auditory processing capabilities in this population. Here, we examined early auditory cortical processing of pure tones and more complex phonemes in females with Rett Syndrome (RTT), by recording high-density auditory evoked potentials (AEP), which allow for objective evaluation of the timing and severity of processing deficits along the auditory processing hierarchy. We compared AEPs of 12 females with RTT to those of 21 typically developing (TD) peers aged 4-21 years, interrogating the first four major components of the AEP (P1: 60-90 ms; N1: 100-130 ms; P2: 135-165 ms; and N2: 245-275 ms). Atypicalities were evident in RTT at the initial stage of processing. Whereas the P1 showed increased amplitude to phonemic inputs relative to tones in TD participants, this modulation by stimulus complexity was absent in RTT. Interestingly, the subsequent N1 did not differ between groups, whereas the following P2 was hugely diminished in RTT, regardless of stimulus complexity. The N2 was similarly smaller in RTT and did not differ as a function of stimulus type. The P2 effect was remarkably robust in differentiating between groups with near perfect separation between the two groups despite the wide age range of our samples. Given this robustness, along with the observation that P2 amplitude was significantly associated with RTT symptom severity, the P2 has the potential to serve as a monitoring, treatment response, or even surrogate endpoint biomarker. Compellingly, the reduction of P2 in patients with RTT mimics findings in animal models of RTT, providing a translational bridge between pre-clinical and human research.
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Affiliation(s)
- Olga V. Sysoeva
- grid.412750.50000 0004 1936 9166The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY USA ,grid.240283.f0000 0001 2152 0791The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY USA ,grid.4886.20000 0001 2192 9124The Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - Sophie Molholm
- grid.412750.50000 0004 1936 9166The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY USA ,grid.240283.f0000 0001 2152 0791The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY USA
| | - Aleksandra Djukic
- grid.240283.f0000 0001 2152 0791The Rett Syndrome Center, Department of Neurology, Montefiore Medical Center & Albert Einstein College of Medicine, Bronx, NY USA
| | - Hans-Peter Frey
- grid.240283.f0000 0001 2152 0791The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY USA
| | - John J. Foxe
- grid.412750.50000 0004 1936 9166The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY USA ,grid.240283.f0000 0001 2152 0791The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY USA
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Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [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: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
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Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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45
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MeCP2 and Chromatin Compartmentalization. Cells 2020; 9:cells9040878. [PMID: 32260176 PMCID: PMC7226738 DOI: 10.3390/cells9040878] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 12/24/2022] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a multifunctional epigenetic reader playing a role in transcriptional regulation and chromatin structure, which was linked to Rett syndrome in humans. Here, we focus on its isoforms and functional domains, interactions, modifications and mutations found in Rett patients. Finally, we address how these properties regulate and mediate the ability of MeCP2 to orchestrate chromatin compartmentalization and higher order genome architecture.
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Tillotson R, Bird A. The Molecular Basis of MeCP2 Function in the Brain. J Mol Biol 2020; 432:1602-1623. [PMID: 31629770 DOI: 10.1016/j.jmb.2019.10.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/14/2022]
Abstract
MeCP2 is a reader of the DNA methylome that occupies a large proportion of the genome due to its high abundance and the frequency of its target sites. It has been the subject of extensive study because of its link with 'MECP2-related disorders', of which Rett syndrome is the most prevalent. This review integrates evidence from patient mutation data with results of experimental studies using mouse models, cell lines and in vitro systems to critically evaluate our understanding of MeCP2 protein function. Recent evidence challenges the idea that MeCP2 is a multifunctional hub that integrates diverse processes to underpin neuronal function, suggesting instead that its primary role is to recruit the NCoR1/2 co-repressor complex to methylated sites in the genome, leading to dampening of gene expression.
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Affiliation(s)
- Rebekah Tillotson
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada; Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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Fallah MS, Eubanks JH. Seizures in Mouse Models of Rare Neurodevelopmental Disorders. Neuroscience 2020; 445:50-68. [PMID: 32059984 DOI: 10.1016/j.neuroscience.2020.01.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 02/07/2023]
Abstract
Genetic neurodevelopmental disorders - that often include epilepsy as part of their phenotype - are a heterogeneous and clinically challenging spectrum of disorders in children. Although seizures often contribute significantly to morbidity in these affected populations, the mechanisms of epileptogenesis in these conditions remain poorly understood. Different model systems have been developed to aid in unraveling these mechanisms, which include a number of specific mutant mouse lines which genocopy specific general types of mutations present in patients. These mouse models have not only allowed for assessments of behavioral and electrographic seizure phenotypes to be ascertained, but also have allowed effects on the neurodevelopmental alterations and cognitive impairments associated with these disorders to be examined. In addition, these models play a role in advancing our understanding of these epileptic processes and developing preclinical therapeutics. The concordance of seizure phenotypes - in a select group of rare, genetic, neurodevelopmental disorders and epileptic encephalopathies - found between human patients and their model counterparts will be summarized. This review aims to assess whether models of Rett syndrome, CDKL5 deficiency disorder, Fragile-X syndrome, Dravet syndrome, and Ohtahara syndrome phenocopy the seizures seen in human patients.
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Affiliation(s)
- Merrick S Fallah
- Division of Experimental and Translational Neuroscience, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario M5T 0S8, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - James H Eubanks
- Division of Experimental and Translational Neuroscience, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario M5T 0S8, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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Affinity for DNA Contributes to NLS Independent Nuclear Localization of MeCP2. Cell Rep 2020; 24:2213-2220. [PMID: 30157418 PMCID: PMC6130050 DOI: 10.1016/j.celrep.2018.07.099] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 06/22/2018] [Accepted: 07/26/2018] [Indexed: 12/14/2022] Open
Abstract
MeCP2 is a nuclear protein that is mutated in the severe neurological disorder Rett syndrome (RTT). The ability to target β-galactosidase to the nucleus was previously used to identify a conserved nuclear localization signal (NLS) in MeCP2 that interacts with the nuclear import factors KPNA3 and KPNA4. Here, we report that nuclear localization of MeCP2 does not depend on its NLS. Instead, our data reveal that an intact methyl-CpG binding domain (MBD) is sufficient for nuclear localization, suggesting that MeCP2 can be retained in the nucleus by its affinity for DNA. Consistent with these findings, we demonstrate that disease progression in a mouse model of RTT is unaffected by an inactivating mutation in the NLS of MeCP2. Taken together, our work reveals an unexpected redundancy between functional domains of MeCP2 in targeting this protein to the nucleus, potentially explaining why NLS-inactivating mutations are rarely associated with disease. Nuclear localization of MeCP2 does not require its NLS DNA binding by MeCP2 contributes to its NLS-independent nuclear localization MeCP2 NLS mutation does not affect pathology in a mouse model of Rett syndrome
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Hsu WL, Ma YL, Liu YC, Tai DJC, Lee EHY. Restoring Wnt6 signaling ameliorates behavioral deficits in MeCP2 T158A mouse model of Rett syndrome. Sci Rep 2020; 10:1074. [PMID: 31974426 PMCID: PMC6978308 DOI: 10.1038/s41598-020-57745-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/09/2019] [Indexed: 01/23/2023] Open
Abstract
The methyl-CpG-binding protein 2 gene, MECP2, is an X chromosome-linked gene encoding the MeCP2 protein, and mutations of MECP2 cause Rett syndrome (RTT). Previous study has shown that re-expression of SUMO-modified MeCP2 in Mecp2-null neurons rescues synaptic and behavioral deficits in Mecp2 conditional knockout mice, whereas about 12-fold decrease in Wnt6 mRNA level was found in MeCP2K412R sumo-mutant mice. Here, we examined the role of Wnt6 in MeCP2 T158A mouse model of RTT. Results show that lentiviral delivery of Wnt6 to the amygdala ameliorates locomotor impairment and social behavioral deficits in these animals. MeCP2 T158A mice show decreased level of GSK-3β phosphorylation and increased level of β-catenin phosphorylation. They also show reduced level of MeCP2 SUMOylation. These alterations were also restored by lenti-Wnt6 transduction. Further, both BDNF and IGF-1 expressions are decreased in MeCP2 T158A mice. Overexpression of Wnt6 increases Bdnf and Igf-1 promoter activity in HEK293T cells in a dose-dependent manner. Lenti-Wnt6 transduction to the amygdala similarly increases the mRNA level and protein expression of BDNF and IGF-1 in MeCP2 T158A mice. Moreover, environmental enrichment (EE) similarly ameliorates the locomotor and social behavioral deficits in MeCP2 T158A mice. One of the mechanisms underlying EE is mediated through enhanced MeCP2 SUMOylation and increased Wnt6 expression in these animals by EE.
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Affiliation(s)
- Wei-Lun Hsu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yun-Li Ma
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yen-Chen Liu
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Derek J C Tai
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Eminy H Y Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
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Cordone V, Pecorelli A, Amicarelli F, Hayek J, Valacchi G. The complexity of Rett syndrome models: Primary fibroblasts as a disease-in-a-dish reliable approach. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.ddmod.2019.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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