1
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Mehta JS, Pahys JM, Saad A, Sponseller P, Andras L, Marks D, Poon S, Klineberg E, White KK, Helenius I, Welborn M, Redding G. Paediatric syndromic scoliosis: proceedings of the half-day course at the 57th annual meeting of the Scoliosis Research Society. Spine Deform 2024; 12:523-543. [PMID: 38366266 DOI: 10.1007/s43390-024-00822-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/30/2023] [Indexed: 02/18/2024]
Abstract
There are some syndromes that present with unique manifestations pertaining to the spinal column. A good working understanding of these common syndromes is useful for the spinal deformity surgeons and related healthcare providers. This review attempts to encompass these unique features and discuss them in three broad groups: hypermobility syndromes, muscle pathology-related syndromes, and syndromes related to poor bone quality. This review explores the features of these syndromes underpinning the aspects of surgical and medical management. This review represents the proceedings of the Paediatric Half-Day Course at the 57th Annual Meeting of the Scoliosis Research Society.
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Affiliation(s)
| | | | - Ahmed Saad
- Royal Orthopaedics Hospital, Birmingham, England
| | - Paul Sponseller
- Division of Paediatric Orthopaedics, Johns Hopkins Medical Centre, Baltimore, USA
| | - Lindsay Andras
- Spine Surgery, Childrens' Hospital Los Angeles, Los Angeles, USA
| | - David Marks
- Birmingham Childrens' Hospital, Birmingham, England
| | | | - Eric Klineberg
- Orthopaedics and Spinal Surgery, UT Health, Houston, USA
| | - Klane K White
- Pediatric Orthopaedics, Childrens' Hospital Colorado, Aurora, USA
| | - Ilkka Helenius
- Paeditric Orthoapedics, University of Turku, Helsinki, Finland
| | | | - Greg Redding
- Paediatric Pulmonology, Seattle Childrens' Hospital, Seattle, USA
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2
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Magielski J, Ruggiero SM, Xian J, Parthasarathy S, Galer P, Ganesan S, Back A, McKee J, McSalley I, Gonzalez AK, Morgan A, Donaher J, Helbig I. The clinical and genetic spectrum of paediatric speech and language disorders in 52,143 individuals. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.04.23.24306192. [PMID: 38712155 PMCID: PMC11071575 DOI: 10.1101/2024.04.23.24306192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Speech and language disorders are known to have a substantial genetic contribution. Although frequently examined as components of other conditions, research on the genetic basis of linguistic differences as separate phenotypic subgroups has been limited so far. Here, we performed an in-depth characterization of speech and language disorders in 52,143 individuals, reconstructing clinical histories using a large-scale data mining approach of the Electronic Medical Records (EMR) from an entire large paediatric healthcare network. The reported frequency of these disorders was the highest between 2 and 5 years old and spanned a spectrum of twenty-six broad speech and language diagnoses. We used Natural Language Processing to assess to which degree clinical diagnosis in full-text notes were reflected in ICD-10 diagnosis codes. We found that aphasia and speech apraxia could be easily retrieved through ICD-10 diagnosis codes, while stuttering as a speech phenotype was only coded in 12% of individuals through appropriate ICD-10 codes. We found significant comorbidity of speech and language disorders in neurodevelopmental conditions (30.31%) and to a lesser degree with epilepsies (6.07%) and movement disorders (2.05%). The most common genetic disorders retrievable in our EMR analysis were STXBP1 (n=21), PTEN (n=20), and CACNA1A (n=18). When assessing associations of genetic diagnoses with specific linguistic phenotypes, we observed associations of STXBP1 and aphasia (P=8.57 × 10-7, CI=18.62-130.39) and MYO7A with speech and language development delay due to hearing loss (P=1.24 × 10-5, CI=17.46-Inf). Finally, in a sub-cohort of 726 individuals with whole exome sequencing data, we identified an enrichment of rare variants in synaptic protein and neuronal receptor pathways and associations of UQCRC1 with expressive aphasia and WASHC4 with abnormality of speech or vocalization. In summary, our study outlines the landscape of paediatric speech and language disorders, confirming the phenotypic complexity of linguistic traits and novel genotype-phenotype associations. Subgroups of paediatric speech and language disorders differ significantly with respect to the composition of monogenic aetiologies.
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Affiliation(s)
- Jan Magielski
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
| | - Sarah M. Ruggiero
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Julie Xian
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
| | - Shridhar Parthasarathy
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
| | - Peter Galer
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shiva Ganesan
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
| | - Amanda Back
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Jillian McKee
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Ian McSalley
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
| | - Alexander K. Gonzalez
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
| | - Angela Morgan
- Murdoch Children’s Research Institute, Parkville 3052, Australia
- Department of Audiology and Speech Pathology, University of Melbourne, Parkville 3052, Australia
| | - Joseph Donaher
- Center for Childhood Communication, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Ingo Helbig
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19146, USA
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
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3
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Byiers BJ, Merbler AM, Raiter A, Burkitt CC, Symons FJ. Caregiver Perspectives on Pain Sensitivity and Pain Experience in Rett Syndrome. Can J Pain 2023; 7:2229400. [PMID: 37533505 PMCID: PMC10392763 DOI: 10.1080/24740527.2023.2229400] [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: 02/13/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 08/04/2023]
Abstract
Background Although delayed or decreased responses to pain are commonly reported among caregivers of individuals with Rett syndrome (RTT), previous studies in relatively small samples have documented that caregivers are concerned about pain, particularly due to gastrointestinal and musculoskeletal conditions. Aims The purpose of the current study was to investigate in detail caregivers' perceptions of pain sensitivity, as well as the types, severity, and effect of pain experienced by individuals with RTT in a larger sample than previous studies. Methods A total of 51 caregivers (mostly mothers) participated in the study, which involved standardized questionnaires and interviews. The individuals with RTT ranged in age from 2 to 52 years of age, and most (n = 46; 90%) met criteria for classic RTT. Results Across the sample, 84% of caregivers reported that they believed that their child was less sensitive to pain compared to her typically developing peers. Despite this perception, 63% of caregivers reported that their child had experienced at least one form of pain in the previous 7 days, and 57% reported their child experienced at least one form of chronic pain. On average, caregivers reported that their child's pain was of moderate severity and interfered with at least one activity of daily living. Conclusions The results suggest that pain is a substantial concern among caregivers of individuals with RTT and indicate that additional research is needed to understand the apparent paradox of frequently reported pain experiences despite widespread perceptions of decreased pain sensitivity.
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Affiliation(s)
- B. J. Byiers
- Department of Educational Psychology, University of Minnesota, Minneapolis, Minnesota, USA
| | - A. M. Merbler
- Department of Educational Psychology, University of Minnesota, Minneapolis, Minnesota, USA
| | - A. Raiter
- Gillette Children’s, St. Paul, Minnesota, USA
| | | | - F. J. Symons
- Department of Educational Psychology, University of Minnesota, Minneapolis, Minnesota, USA
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4
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Kong Y, Li QB, Yuan ZH, Jiang XF, Zhang GQ, Cheng N, Dang N. Multimodal Neuroimaging in Rett Syndrome With MECP2 Mutation. Front Neurol 2022; 13:838206. [PMID: 35280272 PMCID: PMC8904872 DOI: 10.3389/fneur.2022.838206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/24/2022] [Indexed: 01/11/2023] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder characterized by severe cognitive, social, and physical impairments resulting from de novo mutations in the X-chromosomal methyl-CpG binding protein gene 2 (MECP2). While there is still no cure for RTT, exploring up-to date neurofunctional diagnostic markers, discovering new potential therapeutic targets, and searching for novel drug efficacy evaluation indicators are fundamental. Multiple neuroimaging studies on brain structure and function have been carried out in RTT-linked gene mutation carriers to unravel disease-specific imaging features and explore genotype-phenotype associations. Here, we reviewed the neuroimaging literature on this disorder. MRI morphologic studies have shown global atrophy of gray matter (GM) and white matter (WM) and regional variations in brain maturation. Diffusion tensor imaging (DTI) studies have demonstrated reduced fractional anisotropy (FA) in left peripheral WM areas, left major WM tracts, and cingulum bilaterally, and WM microstructural/network topology changes have been further found to be correlated with behavioral abnormalities in RTT. Cerebral blood perfusion imaging studies using single-photon emission CT (SPECT) or PET have evidenced a decreased global cerebral blood flow (CBF), particularly in prefrontal and temporoparietal areas, while magnetic resonance spectroscopy (MRS) and PET studies have contributed to unraveling metabolic alterations in patients with RTT. The results obtained from the available reports confirm that multimodal neuroimaging can provide new insights into a complex interplay between genes, neurotransmitter pathway abnormalities, disease-related behaviors, and clinical severity. However, common limitations related to the available studies include small sample sizes and hypothesis-based and region-specific approaches. We, therefore, conclude that this field is still in its early development phase and that multimodal/multisequence studies with improved post-processing technologies as well as combined PET–MRI approaches are urgently needed to further explore RTT brain alterations.
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Affiliation(s)
- Yu Kong
- Department of Medical Imaging, Affiliated Hospital of Jining Medical University, Jining, China
- *Correspondence: Yu Kong
| | - Qiu-bo Li
- Department of Pediatrics, Affiliated Hospital of Jining Medical University, Jining, China
| | - Zhao-hong Yuan
- Department of Pediatric Rehabilitation, Affiliated Hospital of Jining Medical University, Jining, China
| | - Xiu-fang Jiang
- Department of Pediatric Rehabilitation, Affiliated Hospital of Jining Medical University, Jining, China
| | - Gu-qing Zhang
- Department of Medical Imaging, Affiliated Hospital of Jining Medical University, Jining, China
- Gu-qing Zhang
| | - Nan Cheng
- Department of Medical Imaging, Affiliated Hospital of Jining Medical University, Jining, China
| | - Na Dang
- Department of Medical Imaging, Affiliated Hospital of Jining Medical University, Jining, China
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5
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Santos-Terra J, Deckmann I, Fontes-Dutra M, Schwingel GB, Bambini-Junior V, Gottfried C. Transcription factors in neurodevelopmental and associated psychiatric disorders: A potential convergence for genetic and environmental risk factors. Int J Dev Neurosci 2021; 81:545-578. [PMID: 34240460 DOI: 10.1002/jdn.10141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/23/2021] [Accepted: 07/02/2021] [Indexed: 12/16/2022] Open
Abstract
Neurodevelopmental disorders (NDDs) are a heterogeneous and highly prevalent group of psychiatric conditions marked by impairments in the nervous system. Their onset occurs during gestation, and the alterations are observed throughout the postnatal life. Although many genetic and environmental risk factors have been described in this context, the interactions between them challenge the understanding of the pathways associated with NDDs. Transcription factors (TFs)-a group of over 1,600 proteins that can interact with DNA, regulating gene expression through modulation of RNA synthesis-represent a point of convergence for different risk factors. In addition, TFs organize critical processes like angiogenesis, blood-brain barrier formation, myelination, neuronal migration, immune activation, and many others in a time and location-dependent way. In this review, we summarize important TF alterations in NDD and associated disorders, along with specific impairments observed in animal models, and, finally, establish hypotheses to explain how these proteins may be critical mediators in the context of genome-environment interactions.
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Affiliation(s)
- Júlio Santos-Terra
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Autism Wellbeing And Research Development (AWARD) Institute, BR-UK-CA, Preston, UK
| | - Iohanna Deckmann
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Autism Wellbeing And Research Development (AWARD) Institute, BR-UK-CA, Preston, UK
| | - Mellanie Fontes-Dutra
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Autism Wellbeing And Research Development (AWARD) Institute, BR-UK-CA, Preston, UK
| | - Gustavo Brum Schwingel
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Autism Wellbeing And Research Development (AWARD) Institute, BR-UK-CA, Preston, UK
| | - Victorio Bambini-Junior
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Autism Wellbeing And Research Development (AWARD) Institute, BR-UK-CA, Preston, UK.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - Carmem Gottfried
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,School of Pharmacology and Biomedical Sciences, University of Central Lancashire, Autism Wellbeing And Research Development (AWARD) Institute, BR-UK-CA, Preston, UK
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6
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Matson JL, Dempsey T, Wilkins J. Rett syndrome in adults with severe intellectual disability: Exploration of behavioral characteristics. Eur Psychiatry 2020; 23:460-5. [DOI: 10.1016/j.eurpsy.2007.11.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2007] [Revised: 11/03/2007] [Accepted: 11/05/2007] [Indexed: 10/22/2022] Open
Abstract
AbstractRett syndrome is a genetically linked form of autism spectrum disorder (ASD) accompanied by intellectual disability (ID). The disorder is also characterized by cardiorespiratory dysregulation, disturbance in muscle tone, reduced brain growth and scoliosis. Over 300 studies have been published on the disorder, most of which has focused on identification of causative factors, which appears to be the result of mutations of gene MECP2. Rarely have adults with Rett syndrome been studied, and behavioral characteristics in these individuals are largely unknown. The present study aimed to extend what little is known about behavioral characteristics of Rett syndrome in adults, with particular emphasis on social, communicative, and adaptive behavior. Rett syndrome adults with severe ID were matched to autistic adults with ID and ID only controls. The implications of these data for more fully describing and diagnosing the condition in adults are discussed.
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7
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Brain-enriched microRNAs circulating in plasma as novel biomarkers for Rett syndrome. PLoS One 2019; 14:e0218623. [PMID: 31291284 PMCID: PMC6619658 DOI: 10.1371/journal.pone.0218623] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 06/05/2019] [Indexed: 12/13/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder caused by mutations in the X-linked gene MECP2 (methyl-CpG-binding protein 2). Minimally invasive and accurate biomarkers of disease progression and treatment response could facilitate screening of therapeutic compounds in animal models, enrollment of better-defined participants into clinical trials, and treatment monitoring. In this study, we used a targeted approach based on analysis of brain-enriched microRNAs (miRNAs) circulating in plasma to identify miRNA biomarkers of RTT using Mecp2-mutant mice as a model system and human plasma samples. An “miRNA pair” approach, i.e. the ratio between two miRNAs, was used for data normalization. Specific miRNA pairs and their combinations (classifiers) analyzed in plasma differentiated wild-type from Mecp2 male and female mice with >90% accuracy. Individual miRNA pairs were more effective in distinguishing male (homozygous) animals than female (heterozygous) animals, suggesting that disease severity correlated with the levels of the miRNA biomarkers. In the human study, 30 RTT patients were compared with age-matched controls. The results of this study showed that miRNA classifiers were able to differentiate RTT patients from controls with 85–100% sensitivity. In addition, a comparison of various age groups demonstrated that the dynamics in levels of miRNAs appear to be associated with disease development (involvement of liver, muscle and lipid metabolism in the pathology). Importantly, certain miRNA biomarker pairs were common to both the animal models and human subjects, indicating the similarity between the underlying pathological processes. The data generated in this feasibility study suggest that circulating miRNAs have the potential to be developed as markers of RTT progression and treatment response. Larger clinical studies are needed to further evaluate the findings presented here.
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8
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Müller M. Disturbed redox homeostasis and oxidative stress: Potential players in the developmental regression in Rett syndrome. Neurosci Biobehav Rev 2019; 98:154-163. [PMID: 30639673 DOI: 10.1016/j.neubiorev.2018.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/30/2018] [Accepted: 12/06/2018] [Indexed: 12/16/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder affecting mostly girls. A seemingly normal initial development is followed by developmental stagnation and regression, leading to severe mental impairment with autistic features, motor dysfunction, irregular breathing and epilepsy. Currently, a cure does not exist. Due to the close association of RTT with mitochondrial alterations, cellular redox-impairment and oxidative stress, compounds stabilizing mitochondrial function, cellular redox-homeostasis, and oxidant detoxification are increasingly considered as treatment concepts. Indeed, antioxidants and free-radical scavengers ameliorate certain aspects of the complex and severe clinical presentation of RTT. To further evaluate these strategies, reliable biosensors are needed to quantify redox-conditions in brain and peripheral organs of mouse models or in patient-derived cells. Genetically-encoded redox-sensors meet these requirements. Expressed in transgenic mouse-models such as our unique Rett-redox indicator mice, they will report for any cell type desired the severity of oxidant stress throughout the various disease stages of RTT. Furthermore, these sensors will be crucial to evaluate in vitro and in vivo the outcome of mitochondria- and redox-balance targeted treatments.
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Affiliation(s)
- Michael Müller
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Humboldtallee 23, D-37073 Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro-und Sinnesphysiologie, Humboldtallee 23, D-37073 Göttingen, Germany.
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9
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Jeon SJ, Gonzales EL, Mabunga DFN, Valencia ST, Kim DG, Kim Y, Adil KJL, Shin D, Park D, Shin CY. Sex-specific Behavioral Features of Rodent Models of Autism Spectrum Disorder. Exp Neurobiol 2018; 27:321-343. [PMID: 30429643 PMCID: PMC6221834 DOI: 10.5607/en.2018.27.5.321] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/08/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022] Open
Abstract
Sex is an important factor in understanding the clinical presentation, management, and developmental trajectory of children with neuropsychiatric disorders. While much is known about the clinical and neurobehavioral profiles of males with neuropsychiatric disorders, surprisingly little is known about females in this respect. Animal models may provide detailed mechanistic information about sex differences in autism spectrum disorder (ASD) in terms of manifestation, disease progression, and development of therapeutic options. This review aims to widen our understanding of the role of sex in autism spectrum disorder, by summarizing and comparing behavioral characteristics of animal models. Our current understanding of how differences emerge in boys and girls with neuropsychiatric disorders is limited: Information derived from animal studies will stimulate future research on the role of biological maturation rates, sex hormones, sex-selective protective (or aggravating) factors and psychosocial factors, which are essential to devise sex precision medicine and to improve diagnostic accuracy. Moreover, there is a strong need of novel strategies to elucidate the major mechanisms leading to sex-specific autism features, as well as novel models or methods to examine these sex differences.
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Affiliation(s)
- Se Jin Jeon
- Center for Neuroscience, Korea Institute of Science & Technology, Seoul 02792, Korea.,Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea
| | - Edson Luck Gonzales
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Darine Froy N Mabunga
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Schley T Valencia
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Do Gyeong Kim
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Yujeong Kim
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Keremkleroo Jym L Adil
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Dongpil Shin
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Donghyun Park
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Chan Young Shin
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea.,KU Open Innovation Center, Konkuk University, Seoul 05029, Korea
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10
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Li Y, Shen M, Stockton ME, Zhao X. Hippocampal deficits in neurodevelopmental disorders. Neurobiol Learn Mem 2018; 165:106945. [PMID: 30321651 DOI: 10.1016/j.nlm.2018.10.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 10/08/2018] [Accepted: 10/11/2018] [Indexed: 12/17/2022]
Abstract
Neurodevelopmental disorders result from impaired development or maturation of the central nervous system. Both genetic and environmental factors can contribute to the pathogenesis of these disorders; however, the exact causes are frequently complex and unclear. Individuals with neurodevelopmental disorders may have deficits with diverse manifestations, including challenges with sensory function, motor function, learning, memory, executive function, emotion, anxiety, and social ability. Although these functions are mediated by multiple brain regions, many of them are dependent on the hippocampus. Extensive research supports important roles of the mammalian hippocampus in learning and cognition. In addition, with its high levels of activity-dependent synaptic plasticity and lifelong neurogenesis, the hippocampus is sensitive to experience and exposure and susceptible to disease and injury. In this review, we first summarize hippocampal deficits seen in several human neurodevelopmental disorders, and then discuss hippocampal impairment including hippocampus-dependent behavioral deficits found in animal models of these neurodevelopmental disorders.
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Affiliation(s)
- Yue Li
- Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China; Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Minjie Shen
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Michael E Stockton
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA.
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11
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Le Thi Thanh H, Do Thi Diem T, Duy CV, Thanh HLT, Phuong HBT, Thanh LN. Spectrum of MECP2 mutations in Vietnamese patients with RETT syndrome. BMC MEDICAL GENETICS 2018; 19:137. [PMID: 30081849 PMCID: PMC6090653 DOI: 10.1186/s12881-018-0658-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/30/2018] [Indexed: 11/29/2022]
Abstract
Background Rett syndrome (RTT) is a severe neurodevelopmental disorder in children characterized by a normal neurodevelopmental process in the first 6–18 months followed by a period of motor and vocal deterioration with stereotypic hand movements. Incidence of RTT is mostly due to de novo mutation in the MECP2 gene (methyl-CpG-binding protein 2). Methods The study assessed 27 female patients presented with classical RTT phenotype age range from 18 months to 48 months. Specialist carried out the clinical evaluation and diagnosis according to RTT diagnosis criteria. Blood samples from patients were then collected for genomic DNA extraction. We next performed MECP2 gene amplification and sequencing of the whole coding region to screen for mutations. Result MECP2 mutation was found in 20 patients (74%) including: 2 missense, 4 nonsense, 6 frameshift and 2 deletion mutation. The study identified 14 pathogenic mutations which we found 4 mutation, to our knowledge and extensive search, not priory reported in any mutation database or publication: c.1384-1385DelGT, c.1205insT, c.717delC and c.1132_1207del77. High percentage of C > T (70%) in CpG sites mutation was found. Conclusion Our result reveals a high percentage of C > T mutation in CpG hot spot, which is more prone to modification and more likely to be detected in RTT as a disorder is strictly due to de novo mutations. The study is the first to identify the mutation spectrum of MECP2 gene in Vietnamese patients and also an important step toward better diagnosis and care for RTT patients in Vietnam.
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Affiliation(s)
- Huong Le Thi Thanh
- Department of Gene Technology - Vinmec Research Institute of Stem cell and Gene Technology, 458 Minh Khai Street, Hanoi, Hai Ba Trung district, Vietnam.
| | - Trinh Do Thi Diem
- Department of Gene Technology - Vinmec Research Institute of Stem cell and Gene Technology, 458 Minh Khai Street, Hanoi, Hai Ba Trung district, Vietnam
| | - Chinh Vu Duy
- Vinmec International Hospital, 458 Minh Khai Street, Hai Ba Trung District, Hanoi, Vietnam
| | - Ha Ly Thi Thanh
- Department of Gene Technology - Vinmec Research Institute of Stem cell and Gene Technology, 458 Minh Khai Street, Hanoi, Hai Ba Trung district, Vietnam
| | - Hoa Bui Thi Phuong
- Department of Gene Technology - Vinmec Research Institute of Stem cell and Gene Technology, 458 Minh Khai Street, Hanoi, Hai Ba Trung district, Vietnam
| | - Liem Nguyen Thanh
- Department of Gene Technology - Vinmec Research Institute of Stem cell and Gene Technology, 458 Minh Khai Street, Hanoi, Hai Ba Trung district, Vietnam
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12
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Hayes JA, Kottick A, Picardo MCD, Halleran AD, Smith RD, Smith GD, Saha MS, Del Negro CA. Transcriptome of neonatal preBötzinger complex neurones in Dbx1 reporter mice. Sci Rep 2017; 7:8669. [PMID: 28819234 PMCID: PMC5561182 DOI: 10.1038/s41598-017-09418-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/24/2017] [Indexed: 12/14/2022] Open
Abstract
We sequenced the transcriptome of brainstem interneurons in the specialized respiratory rhythmogenic site dubbed preBötzinger Complex (preBötC) from newborn mice. To distinguish molecular characteristics of the core oscillator we compared preBötC neurons derived from Dbx1-expressing progenitors that are respiratory rhythmogenic to neighbouring non-Dbx1-derived neurons, which support other respiratory and non-respiratory functions. Results in three categories are particularly salient. First, Dbx1 preBötC neurons express κ-opioid receptors in addition to μ-opioid receptors that heretofore have been associated with opiate respiratory depression, which may have clinical applications. Second, Dbx1 preBötC neurons express the hypoxia-inducible transcription factor Hif1a at levels three-times higher than non-Dbx1 neurons, which links core rhythmogenic microcircuits to O2-related chemosensation for the first time. Third, we detected a suite of transcription factors including Hoxa4 whose expression pattern may define the rostral preBötC border, Pbx3 that may influence ipsilateral connectivity, and Pax8 that may pertain to a ventrally-derived subset of Dbx1 preBötC neurons. These data establish the transcriptomic signature of the core respiratory oscillator at a perinatal stage of development.
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Affiliation(s)
- John A Hayes
- Department of Applied Science, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Andrew Kottick
- Department of Applied Science, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Maria Cristina D Picardo
- Department of Applied Science, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Andrew D Halleran
- Department of Biology, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Ronald D Smith
- Department of Applied Science, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Gregory D Smith
- Department of Applied Science, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Margaret S Saha
- Department of Biology, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA
| | - Christopher A Del Negro
- Department of Applied Science, Integrated Science Center, 540 Landrum Dr., The College of William and Mary, Williamsburg, VA, 23185, USA.
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Stevens AJ, Rucklidge JJ, Kennedy MA. Epigenetics, nutrition and mental health. Is there a relationship? Nutr Neurosci 2017; 21:602-613. [PMID: 28553986 DOI: 10.1080/1028415x.2017.1331524] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many aspects of human development and disease are influenced by the interaction between genetic and environmental factors. Understanding how our genes respond to the environment is central to managing health and disease, and is one of the major contemporary challenges in human genetics. Various epigenetic processes affect chromosome structure and accessibility of deoxyribonucleic acid (DNA) to the enzymatic machinery that leads to expression of genes. One important epigenetic mechanism that appears to underlie the interaction between environmental factors, including diet, and our genome, is chemical modification of the DNA. The best understood of these modifications is methylation of cytosine residues in DNA. It is now recognized that the pattern of methylated cytosines throughout our genomes (the 'methylome') can change during development and in response to environmental cues, often with profound effects on gene expression. Many dietary constituents may indirectly influence genomic pathways that methylate DNA, and there is evidence for biochemical links between nutritional quality and mental health. Deficiency of both macro- and micronutrients has been associated with increased behavioural problems, and nutritional supplementation has proven efficacious in treatment of certain neuropsychiatric disorders. In this review we examine evidence from the fields of nutrition, developmental biology, and mental health that supports dietary impacts on epigenetic processes, particularly DNA methylation. We then consider whether such processes could underlie the demonstrated efficacy of dietary supplementation in treatment of mental disorders, and whether targeted manipulation of DNA methylation patterns using controlled dietary supplementation may be of wider clinical value.
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Affiliation(s)
- Aaron J Stevens
- a Department of Pathology , University of Otago , P.O. Box 4345, Christchurch , New Zealand
| | - Julia J Rucklidge
- b Department of Psychology , University of Canterbury , Christchurch , New Zealand
| | - Martin A Kennedy
- a Department of Pathology , University of Otago , P.O. Box 4345, Christchurch , New Zealand
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Maphis NM, Jiang S, Binder J, Wright C, Gopalan B, Lamb BT, Bhaskar K. Whole Genome Expression Analysis in a Mouse Model of Tauopathy Identifies MECP2 as a Possible Regulator of Tau Pathology. Front Mol Neurosci 2017; 10:69. [PMID: 28367114 PMCID: PMC5355442 DOI: 10.3389/fnmol.2017.00069] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 02/28/2017] [Indexed: 11/14/2022] Open
Abstract
Increasing evidence suggests that hyperphosphorylation and aggregation of microtubule-associated protein tau (MAPT or tau) correlates with the development of cognitive impairment in Alzheimer’s disease (AD) and related tauopathies. While numerous attempts have been made to model AD-relevant tau pathology in various animal models, there has been very limited success for these models to fully recapitulate the progression of disease as seen in human tauopathies. Here, we performed whole genome gene expression in a genomic mouse model of tauopathy that expressed human MAPT gene under the control of endogenous human MAPT promoter and also were complete knockout for endogenous mouse tau [referred to as ‘hTauMaptKO(Duke)′ mice]. First, whole genome expression analysis revealed 64 genes, which were differentially expressed (32 up-regulated and 32 down-regulated) in the hippocampus of 6-month-old hTauMaptKO(Duke) mice compared to age-matched non-transgenic controls. Genes relevant to neuronal function or neurological disease include up-regulated genes: PKC-alpha (Prkca), MECP2 (Mecp2), STRN4 (Strn4), SLC40a1 (Slc40a1), POLD2 (Pold2), PCSK2 (Pcsk2), and down-regulated genes: KRT12 (Krt12), LASS1 (Cers1), PLAT (Plat), and NRXN1 (Nrxn1). Second, network analysis suggested anatomical structure development, cellular metabolic process, cell death, signal transduction, and stress response were significantly altered biological processes in the hTauMaptKO(Duke) mice as compared to age-matched non-transgenic controls. Further characterization of a sub-group of significantly altered genes revealed elevated phosphorylation of MECP2 (methyl-CpG-binding protein-2), which binds to methylated CpGs and associates with chromatin, in hTauMaptKO(Duke) mice compared to age-matched controls. Third, phoshpho-MECP2 was elevated in autopsy brain samples from human AD compared to healthy controls. Finally, siRNA-mediated knockdown of MECP2 in human tau expressing N2a cells resulted in a significant decrease in total and phosphorylated tau. Together, these results suggest that MECP2 is a potential novel regulator of tau pathology relevant to AD and tauopathies.
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Affiliation(s)
- Nicole M Maphis
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
| | - Shanya Jiang
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
| | - Jessica Binder
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
| | - Carrie Wright
- Lieber Institute for Brain Development, Baltimore MD, USA
| | - Banu Gopalan
- Department of Biostatistics, Cleveland Clinic Foundation Cleveland OH, USA
| | - Bruce T Lamb
- Stark Neurosciences Research Institute, Indiana University, Indianapolis IN, USA
| | - Kiran Bhaskar
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
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15
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Lin YC, Frei JA, Kilander MBC, Shen W, Blatt GJ. A Subset of Autism-Associated Genes Regulate the Structural Stability of Neurons. Front Cell Neurosci 2016; 10:263. [PMID: 27909399 PMCID: PMC5112273 DOI: 10.3389/fncel.2016.00263] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/28/2016] [Indexed: 12/15/2022] Open
Abstract
Autism spectrum disorder (ASD) comprises a range of neurological conditions that affect individuals’ ability to communicate and interact with others. People with ASD often exhibit marked qualitative difficulties in social interaction, communication, and behavior. Alterations in neurite arborization and dendritic spine morphology, including size, shape, and number, are hallmarks of almost all neurological conditions, including ASD. As experimental evidence emerges in recent years, it becomes clear that although there is broad heterogeneity of identified autism risk genes, many of them converge into similar cellular pathways, including those regulating neurite outgrowth, synapse formation and spine stability, and synaptic plasticity. These mechanisms together regulate the structural stability of neurons and are vulnerable targets in ASD. In this review, we discuss the current understanding of those autism risk genes that affect the structural connectivity of neurons. We sub-categorize them into (1) cytoskeletal regulators, e.g., motors and small RhoGTPase regulators; (2) adhesion molecules, e.g., cadherins, NCAM, and neurexin superfamily; (3) cell surface receptors, e.g., glutamatergic receptors and receptor tyrosine kinases; (4) signaling molecules, e.g., protein kinases and phosphatases; and (5) synaptic proteins, e.g., vesicle and scaffolding proteins. Although the roles of some of these genes in maintaining neuronal structural stability are well studied, how mutations contribute to the autism phenotype is still largely unknown. Investigating whether and how the neuronal structure and function are affected when these genes are mutated will provide insights toward developing effective interventions aimed at improving the lives of people with autism and their families.
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Affiliation(s)
- Yu-Chih Lin
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Jeannine A Frei
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Michaela B C Kilander
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Wenjuan Shen
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Gene J Blatt
- Laboratory of Autism Neurocircuitry, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
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Janc OA, Hüser MA, Dietrich K, Kempkes B, Menzfeld C, Hülsmann S, Müller M. Systemic Radical Scavenger Treatment of a Mouse Model of Rett Syndrome: Merits and Limitations of the Vitamin E Derivative Trolox. Front Cell Neurosci 2016; 10:266. [PMID: 27895554 PMCID: PMC5109403 DOI: 10.3389/fncel.2016.00266] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/01/2016] [Indexed: 12/21/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder typically arising from spontaneous mutations in the X-chromosomal methyl-CpG binding protein 2 (MECP2) gene. The almost exclusively female Rett patients show an apparently normal development during their first 6-18 months of life. Subsequently, cognitive- and motor-impairment, hand stereotypies, loss of learned skills, epilepsy and irregular breathing manifest. Early mitochondrial impairment and oxidative challenge are considered to facilitate disease progression. Along this line, we recently confirmed in vitro that acute treatment with the vitamin E-derivative Trolox dampens neuronal hyperexcitability, reinstates synaptic plasticity, ameliorates cellular redox balance and improves hypoxia tolerance in male MeCP2-deficient (Mecp2-/y ) mouse hippocampus. Pursuing these promising findings, we performed a preclinical study to define the merit of systemic Trolox administration. Blinded, placebo-controlled in vivo treatment of male mice started at postnatal day (PD) 10-11 and continued for ~40 days. Compounds (vehicle only, 10 mg/kg or 40 mg/kg Trolox) were injected intraperitoneally every 48 h. Detailed phenotyping revealed that in Mecp2-/y mice, blood glucose levels, lipid peroxidation, synaptic short-term plasticity, hypoxia tolerance and certain forms of environmental exploration were improved by Trolox. Yet, body weight and size, motor function and the rate and regularity of breathing did not improve. In conclusion, in vivo Trolox treatment partially ameliorated a subset of symptoms of the complex Rett phenotype, thereby confirming a partial merit of the vitamin E-derivative based pharmacotherapy. Yet, it also became evident that frequent animal handling and the route of drug administration are critical issues to be optimized in future trials.
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Affiliation(s)
- Oliwia A Janc
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Marc A Hüser
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Germany
| | - Katharina Dietrich
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Belinda Kempkes
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Germany
| | - Christiane Menzfeld
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Swen Hülsmann
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Klinik für Anästhesiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Michael Müller
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
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17
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Gendrel AV, Marion-Poll L, Katoh K, Heard E. Random monoallelic expression of genes on autosomes: Parallels with X-chromosome inactivation. Semin Cell Dev Biol 2016; 56:100-110. [PMID: 27101886 DOI: 10.1016/j.semcdb.2016.04.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/08/2016] [Accepted: 04/15/2016] [Indexed: 01/04/2023]
Abstract
Genes are generally expressed from their two alleles, except in some particular cases such as random inactivation of one of the two X chromosomes in female mammals or imprinted genes which are expressed only from the maternal or the paternal allele. A lesser-known phenomenon is random monoallelic expression (RME) of autosomal genes, where genes can be stably expressed in a monoallelic manner, from either one of the parental alleles. Studies on autosomal RME face several challenges. First, RME that is based on epigenetic mechanisms has to be distinguished from biased expression of one allele caused by a DNA sequence polymorphism in a regulatory element. Second, RME should not be confused with transient monoallelic expression often observed in single cell analyses, and that often corresponds to dynamic bursting of expression. Thanks to analyses on clonal cell populations, the existence of RME in cultured cells is now well established. Future studies of RME in vivo will have to overcome tissue heterogeneity and certain technical limitations. Here, we discuss current knowledge on autosomal RME, as well as possible mechanisms controlling these expression patterns and potential implications for development and disease, drawing parallels with what is known for X-chromosome inactivation, a paradigm of random monoallelic expression.
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Affiliation(s)
- Anne-Valerie Gendrel
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France.
| | - Lucile Marion-Poll
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France
| | - Kimiko Katoh
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France
| | - Edith Heard
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France.
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18
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Leong WY, Lim ZH, Korzh V, Pietri T, Goh ELK. Methyl-CpG Binding Protein 2 (Mecp2) Regulates Sensory Function Through Sema5b and Robo2. Front Cell Neurosci 2015; 9:481. [PMID: 26733807 PMCID: PMC4685056 DOI: 10.3389/fncel.2015.00481] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 11/30/2015] [Indexed: 12/31/2022] Open
Abstract
Mutations in the gene encoding the MECP2 underlies Rett syndrome, a neurodevelopmental disorder in young females. Although reduced pain sensitivity in Rett syndrome patients and in partial MeCP2 deficient mice had been reported, these previous studies focused predominantly on motor impairments. Therefore, it is still unknown how MeCP2 is involved in these sensory defects. In addition, the human disease manifestations where males with mutations in MECP2 gene normally do not survive and females show typical neurological symptoms only after 18 months of age, is profoundly different in MeCP2-deficient mouse where all animals survived, and males but not females displayed Rett syndrome phenotypes at an early age. Thus, the mecp2-deficient zebrafish serves as an additional animal model to aid in deciphering the role and mechanisms of Mecp2 in neurodevelopment. Here, we used two independent methods of silencing expression of Mecp2 in zebrafish to uncover a novel role of Mecp2 in trigeminal ganglion sensory neurons during the embryonic development. mecp2-null mutation and morpholino-mediated silencing of Mecp2 in the zebrafish embryos resulted in defects in peripheral innervation of trigeminal sensory neurons and consequently affecting the sensory function. These defects were demonstrated to be dependent on the expression of Sema5b and Robo2. The expression of both proteins together could better overcome the defects caused by Mecp2 deficiency as compared to the expression of either Sema5b or Robo2 alone. Sema5b and Robo2 were downregulated upon Mecp2 silencing or in mecp2-null embryos, and Chromatin immunoprecipitation (ChIP) assay using antibody against Mecp2 was able to pull down specific regions of both Sema5b and Robo2 promoters, showing interaction between Mecp2 and the promoters of both genes. In addition, cell-specific expression of Mecp2 can overcome the innervation and sensory response defects in Mecp2 morphants indicating that these MeCP2-mediated defects are cell-autonomous. The sensory deficits caused by Mecp2 deficiency mirror the diminished sensory response observed in Rett syndrome patients. This suggests that zebrafish could be an unconventional but useful model for this disorder manifesting defects that are not easily studied in full using rodent models.
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Affiliation(s)
- Wan Y Leong
- Program in Neuroscience and Behavioral Disorder, Duke-NUS Graduate Medical School, Singapore Singapore
| | - Zhi H Lim
- Program in Neuroscience and Behavioral Disorder, Duke-NUS Graduate Medical School, Singapore Singapore
| | - Vladimir Korzh
- Institute of Molecular and Cell Biology, SingaporeSingapore; Department of Biological Sciences, National University of Singapore, SingaporeSingapore
| | - Thomas Pietri
- Institut de Biologie de l'École Normale Supérieure, Institut National de la Santé et de la Recherche Médicale U1024, Centre National de la Recherche Scientifique UMR 8197 Paris, France
| | - Eyleen L K Goh
- Program in Neuroscience and Behavioral Disorder, Duke-NUS Graduate Medical School, SingaporeSingapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, SingaporeSingapore; KK Research Centre, KK Women's and Children's Hospital, SingaporeSingapore
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Paternain L, Martisova E, Campión J, Martínez JA, Ramírez MJ, Milagro FI. Methyl donor supplementation in rats reverses the deleterious effect of maternal separation on depression-like behaviour. Behav Brain Res 2015; 299:51-8. [PMID: 26628207 DOI: 10.1016/j.bbr.2015.11.031] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/17/2015] [Accepted: 11/21/2015] [Indexed: 12/22/2022]
Abstract
Adverse early life events are associated with altered stress responsiveness and metabolic disturbances in the adult life. Dietary methyl donor supplementation could be able to reverse the negative effects of maternal separation by affecting DNA methylation in the brain. In this study, maternal separation during lactation reduced body weight gain in the female adult offspring without affecting food intake, and altered total and HDL-cholesterol levels. Also, maternal separation induced a cognitive deficit as measured by NORT and an increase in the immobility time in the Porsolt forced swimming test, consistent with increased depression-like behaviour. An 18-week dietary supplementation with methyl donors (choline, betaine, folate and vitamin B12) from postnatal day 60 also reduced body weight without affecting food intake. Some of the deleterious effects induced by maternal separation, such as the abnormal levels of total and HDL-cholesterol, but especially the depression-like behaviour as measured by the Porsolt test, were reversed by methyl donor supplementation. Also, the administration of methyl donors increased total DNA methylation (measured by immunohistochemistry) and affected the expression of insulin receptor in the hippocampus of the adult offspring. However, no changes were observed in the DNA methylation status of insulin receptor and corticotropin-releasing hormone (CRH) promoter regions in the hypothalamus. In summary, methyl donor supplementation reversed some of the deleterious effects of an early life-induced model of depression in rats and altered the DNA methylation profile in the brain.
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Affiliation(s)
- Laura Paternain
- Department of Nutrition, Food Science and Physiology, Centre for Nutrition Research, University of Navarra, c/Irunlarrea 1, 31008 Pamplona, Spain
| | - Eva Martisova
- Department of Pharmacology and Toxicology, University of Navarra, c/Irunlarrea 1, 31008 Pamplona, Spain
| | - Javier Campión
- Department of Nutrition, Food Science and Physiology, Centre for Nutrition Research, University of Navarra, c/Irunlarrea 1, 31008 Pamplona, Spain; CIBERobn, Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición, Carlos III Health Institute, Madrid, Spain
| | - J Alfredo Martínez
- Department of Nutrition, Food Science and Physiology, Centre for Nutrition Research, University of Navarra, c/Irunlarrea 1, 31008 Pamplona, Spain; CIBERobn, Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición, Carlos III Health Institute, Madrid, Spain; IDISNA, Navarra's Health Research Institute, Pamplona, Spain
| | - Maria J Ramírez
- Department of Pharmacology and Toxicology, University of Navarra, c/Irunlarrea 1, 31008 Pamplona, Spain; IDISNA, Navarra's Health Research Institute, Pamplona, Spain.
| | - Fermin I Milagro
- Department of Nutrition, Food Science and Physiology, Centre for Nutrition Research, University of Navarra, c/Irunlarrea 1, 31008 Pamplona, Spain; CIBERobn, Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición, Carlos III Health Institute, Madrid, Spain
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Krishnan N, Krishnan K, Connors CR, Choy MS, Page R, Peti W, Van Aelst L, Shea SD, Tonks NK. PTP1B inhibition suggests a therapeutic strategy for Rett syndrome. J Clin Invest 2015. [PMID: 26214522 DOI: 10.1172/jci80323] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The X-linked neurological disorder Rett syndrome (RTT) presents with autistic features and is caused primarily by mutations in a transcriptional regulator, methyl CpG-binding protein 2 (MECP2). Current treatment options for RTT are limited to alleviating some neurological symptoms; hence, more effective therapeutic strategies are needed. We identified the protein tyrosine phosphatase PTP1B as a therapeutic candidate for treatment of RTT. We demonstrated that the PTPN1 gene, which encodes PTP1B, was a target of MECP2 and that disruption of MECP2 function was associated with increased levels of PTP1B in RTT models. Pharmacological inhibition of PTP1B ameliorated the effects of MECP2 disruption in mouse models of RTT, including improved survival in young male (Mecp2-/y) mice and improved behavior in female heterozygous (Mecp2-/+) mice. We demonstrated that PTP1B was a negative regulator of tyrosine phosphorylation of the tyrosine kinase TRKB, the receptor for brain-derived neurotrophic factor (BDNF). Therefore, the elevated PTP1B that accompanies disruption of MECP2 function in RTT represents a barrier to BDNF signaling. Inhibition of PTP1B led to increased tyrosine phosphorylation of TRKB in the brain, which would augment BDNF signaling. This study presents PTP1B as a mechanism-based therapeutic target for RTT, validating a unique strategy for treating the disease by modifying signal transduction pathways with small-molecule drugs.
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Abstract
Mutations in Methyl-CpG-Binding protein 2 (MECP2) are commonly associated with the neurodevelopmental disorder Rett syndrome (RTT). However, some people with RTT do not have mutations in MECP2, and interestingly there have been people identified with MECP2 mutations that do not have the clinical features of RTT. In this report we present four people with neurodevelopmental abnormalities and clear RTT-disease causing MECP2 mutation but lacking the characteristic clinical features of RTT. One patient's symptoms suggest an extension of the known spectrum of MECP2 associated phenotypes to include global developmental delay with obsessive compulsive disorder and attention deficit hyperactivity disorder. These results reemphasize that RTT should remain a clinical diagnosis, based on the recent consensus criteria.
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Kiran Kumar HB, Castellani C, Maiti S, O'Reilly R, Singh SM. Search for missing schizophrenia genes will require a new developmental neurogenomic perspective. J Genet 2013; 92:335-40. [PMID: 23970094 DOI: 10.1007/s12041-013-0262-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Even the most powerful experimental designs in search of genetic causes of schizophrenia have not met the desired goal. It is imperative to review the reasons for such an outcome and to formulate novel strategies for the future direction of this research in the new era of individual genomes. Here, we will review aspects of neurodevelopmental hypothesis of schizophrenia in the light of novel genomic and epigenomic insights. Specifically, we will argue for the involvement of de novo mutations and epigenetic modifications during neurodevelopment that may result in schizophrenia. Our conclusion is that the successful elucidation of hereditary mechanisms in neuropsychiatric disorders must begin with attention to discrete endophenotypes; consideration of ontogeny, forethought of genome structure including temporal and spatial patterns of (epi) mutations and the use of judicious techniques that go beyond association studies.
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Affiliation(s)
- H B Kiran Kumar
- Molecular Genetics Unit, Department of Biology and Psychiatry, University of Western Ontario, London, Ontario, Canada N6A 5B7
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23
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Panighini A, Duranti E, Santini F, Maffei M, Pizzorusso T, Funel N, Taddei S, Bernardini N, Ippolito C, Virdis A, Costa M. Vascular dysfunction in a mouse model of Rett syndrome and effects of curcumin treatment. PLoS One 2013; 8:e64863. [PMID: 23705018 PMCID: PMC3660336 DOI: 10.1371/journal.pone.0064863] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 04/22/2013] [Indexed: 02/07/2023] Open
Abstract
Mutations in the coding sequence of the X-linked gene MeCP2 (Methyl CpG–binding protein) are present in around 80% of patients with Rett Syndrome, a common cause of intellectual disability in female and to date without any effective pharmacological treatment. A relevant, and so far unexplored feature of RTT patients, is a marked reduction in peripheral circulation. To investigate the relationship between loss of MeCP2 and this clinical aspect, we used the MeCP2 null mouse model B6.129SF1-MeCP2tm1Jae for functional and pharmacological studies. Functional experiments were performed on isolated resistance mesenteric vessels, mounted on a pressurized myograph. Vessels from female MeCP2+/− mice show a reduced endothelium-dependent relaxation, due to a reduced Nitric Oxide (NO) availability secondary to an increased Reactive Oxygen Species (ROS) generation. Such functional aspects are associated with an intravascular increase in superoxide anion production, and a decreased vascular eNOS expression. These alterations are reversed by curcumin administration (5% (w/w) dietary curcumin for 21 days), which restores endothelial NO availability, decreases intravascular ROS production and normalizes vascular eNOS gene expression. In conclusion our findings highlight alterations in the vascular/endothelial system in the absence of a correct function of MeCP2, and uncover related cellular/molecular mechanisms that are rescued by an anti-oxidant treatment.
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MESH Headings
- Animals
- Blood Vessels/drug effects
- Blood Vessels/physiopathology
- Curcumin/administration & dosage
- Curcumin/pharmacology
- Curcumin/therapeutic use
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- Female
- Gene Expression Regulation, Enzymologic/drug effects
- Immunohistochemistry
- Malondialdehyde/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rett Syndrome/complications
- Rett Syndrome/drug therapy
- Rett Syndrome/physiopathology
- Superoxides/metabolism
- Time Factors
- Vascular Diseases/complications
- Vascular Diseases/drug therapy
- Vascular Diseases/physiopathology
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Affiliation(s)
- Anna Panighini
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
| | - Emiliano Duranti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Ferruccio Santini
- Department of Endocrinology and Kidney; University-Hospital of Pisa, Pisa, Italy
| | - Margherita Maffei
- Department of Endocrinology and Kidney; University-Hospital of Pisa, Pisa, Italy
- Dulbecco Telethon Institute, Rome, Italy
- Institute of Food Science, CNR, Avellino, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
- Institute of Psychology, University of Florence, Florence, Italy
| | - Niccola Funel
- Department of Surgery, University of Pisa, Pisa, Italy
| | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Nunzia Bernardini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Chiara Ippolito
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Agostino Virdis
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- * E-mail: (AV); (MC)
| | - Mario Costa
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
- Scuola Normale Superiore, Pisa, Italy
- * E-mail: (AV); (MC)
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Ghosh SK, McCormick TS, Eapen BL, Yohannes E, Chance MR, Weinberg A. Comparison of epigenetic profiles of human oral epithelial cells from HIV-positive (on HAART) and HIV-negative subjects. Epigenetics 2013; 8:703-9. [PMID: 23804146 PMCID: PMC3781189 DOI: 10.4161/epi.25028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
HIV-infected subjects on highly active antiretroviral therapy (HAART) are susceptible to comorbid microbial infections in the oral cavity. We observed that primary oral epithelial cells (POECs) isolated from HIV+ subjects on HAART grow more slowly and are less innate immune responsive to microbial challenge when compared with POECs from normal subjects. These aberrant cells also demonstrate epigenetic differences that include reduction in histone deacetylase 1 (HDAC-1) levels and reduced total DNA methyltransferase (DNMT) activity specific to enzymes DNMT1 and DNMT3A. The DNMT activity correlates well with global DNA methylation, indicating that aberrant DNMT activity in HIV+ (on HAART) POECs leads to an aberrantly methylated epithelial cell phenotype. Overall, our results lead us to hypothesize that, in patients with chronic HIV infection on HAART, epigenetic changes in key genes result in increased vulnerability to microbial infection in the oral cavity.
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Affiliation(s)
- Santosh K Ghosh
- Department of Biological Sciences, Case Western Reserve University, Cleveland, OH, USA.
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25
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Spectrum of MECP2 gene mutations in a cohort of Indian patients with Rett syndrome: Report of two novel mutations. Gene 2013; 515:78-83. [DOI: 10.1016/j.gene.2012.11.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 10/30/2012] [Accepted: 11/27/2012] [Indexed: 11/23/2022]
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26
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Molecular diagnostic dilemmas in Rett syndrome. Brain Dev 2012; 34:750-5. [PMID: 22277191 DOI: 10.1016/j.braindev.2011.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 12/28/2011] [Accepted: 12/29/2011] [Indexed: 11/20/2022]
Abstract
Rett syndrome (OMIM 312750) is a progressive, X-linked neurodevelopmental disorder caused by mutations in the MECP2 gene located on chromosome Xq28. The disorder is characterized by a period of normal development during the first 6-18months of life, followed by gradual loss of skills already gained, such as speech and purposeful movement of the hands. The majority of cases are sporadic and represent "de novo" mutations. In this study we summarize the results of diagnostic testing of 30 patients with Rett syndrome (RTT) or mental retardation of unknown etiology using bidirectional sequencing of the open reading frame of the MECP2 gene. Twenty different variants were identified in those patients including 12 missense (R133C, P152R, T158M, V300I, I303M, R306C, T311M, R344W, A358T, P384L, A443T, V481M), four nonsense (R168X, K192X, R255X, R270X), two deletion (E137_L386del, I293_S350del), and two frameshift (S291QfsX26, G343AfsX6) mutations. Seven of the twenty variants identified were novel mutations (E137_L386del, K192X, S291QfsX26, G343AfsX6, I293_S350del, P384L, and A443T). In the cases with novel or non-recurrent missense mutations, family studies were performed to investigate genotype-phenotype correlations. Our results demonstrate the importance of family studies and highlight the complexity of interpretation of MECP2 alterations, which may or may not be disease-associated.
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27
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Molecular analysis of MECP2 gene in Egyptian patients with Rett syndrome. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2012. [DOI: 10.1016/j.ejmhg.2011.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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28
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Khajuria R, Gupta N, Sapra S, Gulati S, Ghosh M, Kalra V, Kabra M. Novel non-identical MECP2 mutations in Rett syndrome family: a rare presentation. Brain Dev 2012; 34:28-31. [PMID: 21300488 DOI: 10.1016/j.braindev.2011.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 12/26/2010] [Accepted: 01/12/2011] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Rett syndrome (RS), an X-linked neurodevelopmental disorder and the common cause of mental retardation in females, is caused by methyl CpG binding protein 2 (MECP2) gene mutations with a frequency of more than 95% in classical Rett patients. Majority of RS cases are sporadic but few familial cases caused by either skewed X-chromosome inactivation in healthy female carriers or mosaicism in male carriers are also reported. Most of the times, the mutation carried in a family is the same as found in affected child. METHODS AND RESULTS Here we report a unique family carrying non-identical MECP2 mutations in exon 2 wherein the proband with classical RS was carrying a de-novo early truncating frameshift mutation while her asymptomatic mother was carrying a missense mutation, both predicted as pathogenic mutations. CONCLUSIONS These findings further validate the importance of MECP2 mutation screening in parents of all mutation positive patients and careful evaluation of the pathogenicity of the mutation found in asymptomatic carriers before providing genetic counseling to the family. The results also propose the role of other factors including other gene mutations, environmental and epigenetics factors in modifying the expression of MECP2 mutations.
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Affiliation(s)
- Rajni Khajuria
- Genetics Unit, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi 110029, India
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29
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Lv J, Liu H, Su J, Wu X, Liu H, Li B, Xiao X, Wang F, Wu Q, Zhang Y. DiseaseMeth: a human disease methylation database. Nucleic Acids Res 2011; 40:D1030-5. [PMID: 22135302 PMCID: PMC3245164 DOI: 10.1093/nar/gkr1169] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
DNA methylation is an important epigenetic modification for genomic regulation in higher organisms that plays a crucial role in the initiation and progression of diseases. The integration and mining of DNA methylation data by methylation-specific PCR and genome-wide profiling technology could greatly assist the discovery of novel candidate disease biomarkers. However, this is difficult without a comprehensive DNA methylation repository of human diseases. Therefore, we have developed DiseaseMeth, a human disease methylation database (http://bioinfo.hrbmu.edu.cn/diseasemeth). Its focus is the efficient storage and statistical analysis of DNA methylation data sets from various diseases. Experimental information from over 14 000 entries and 175 high-throughput data sets from a wide number of sources have been collected and incorporated into DiseaseMeth. The latest release incorporates the gene-centric methylation data of 72 human diseases from a variety of technologies and platforms. To facilitate data extraction, DiseaseMeth supports multiple search options such as gene ID and disease name. DiseaseMeth provides integrated gene methylation data based on cross-data set analysis for disease and normal samples. These can be used for in-depth identification of differentially methylated genes and the investigation of gene–disease relationship.
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Affiliation(s)
- Jie Lv
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150081, China
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30
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Bogdanović O, Veenstra GJC. Affinity-based enrichment strategies to assay methyl-CpG binding activity and DNA methylation in early Xenopus embryos. BMC Res Notes 2011; 4:300. [PMID: 21851637 PMCID: PMC3169474 DOI: 10.1186/1756-0500-4-300] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 08/18/2011] [Indexed: 01/12/2023] Open
Abstract
Background DNA methylation is a widespread epigenetic modification in vertebrate genomes. Genomic sites of DNA methylation can be bound by methyl-CpG-binding domain proteins (MBDs) and specific zinc finger proteins, which can recruit co-repressor complexes to silence transcription on targeted loci. The binding to methylated DNA may be regulated by post-translational MBD modifications. Findings A methylated DNA affinity precipitation method was implemented to assay binding of proteins to methylated DNA. Endogenous MeCP2 and MBD3 were precipitated from Xenopus oocyte extracts and conditions for methylation-specific binding were optimized. For a reverse experiment, DNA methylation in early Xenopus embryos was assessed by MBD affinity capture. Conclusions A methylated DNA affinity resin can be applied to probe for MBD activity in extracts. This assay has a broad application potential as it can be coupled to downstream procedures such as western blotting, fluorimetric HDAC assays and quantitative mass spectrometry. Methylated DNA affinity capture by methyl-CpG binding proteins produces fractions highly enriched for methylated DNA, suitable for coupling to next generation sequencing technologies. The two enrichment strategies allow probing of methyl-CpG protein interactions in early vertebrate oocytes and embryos.
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Affiliation(s)
- Ozren Bogdanović
- Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, Faculty of Science, (Geert Grooteplein 28), Nijmegen, (6525 GA), The Netherlands.
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31
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Bogdanović O, Long SW, van Heeringen SJ, Brinkman AB, Gómez-Skarmeta JL, Stunnenberg HG, Jones PL, Veenstra GJC. Temporal uncoupling of the DNA methylome and transcriptional repression during embryogenesis. Genome Res 2011; 21:1313-27. [PMID: 21636662 PMCID: PMC3149498 DOI: 10.1101/gr.114843.110] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 04/14/2011] [Indexed: 12/18/2022]
Abstract
DNA methylation is a tightly regulated epigenetic mark associated with transcriptional repression. Next-generation sequencing of purified methylated DNA obtained from early Xenopus tropicalis embryos demonstrates that this genome is heavily methylated during blastula and gastrula stages. Although DNA methylation is largely absent from transcriptional start sites marked with histone H3 lysine 4 trimethylation (H3K4me3), we find both promoters and gene bodies of active genes robustly methylated. In contrast, DNA methylation is absent in large H3K27me3 domains, indicating that these two repression pathways have different roles. Comparison with chromatin state maps of human ES cells reveals strong conservation of epigenetic makeup and gene regulation between the two systems. Strikingly, genes that are highly expressed in pluripotent cells and in Xenopus embryos but not in differentiated cells exhibit relatively high DNA methylation. Therefore, we tested the repressive potential of DNA methylation using transient and transgenic approaches and show that methylated promoters are robustly transcribed in blastula- and gastrula-stage embryos, but not in oocytes or late embryos. These findings have implications for reprogramming and the epigenetic regulation of pluripotency and differentiation and suggest a relatively open, pliable chromatin state in early embryos followed by reestablished methylation-dependent transcriptional repression during organogenesis and differentiation.
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Affiliation(s)
- Ozren Bogdanović
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, 6500 Nijmegen, The Netherlands
| | - Steven W. Long
- Department of Cell and Developmental Biology, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA
| | - Simon J. van Heeringen
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, 6500 Nijmegen, The Netherlands
| | - Arie B. Brinkman
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, 6500 Nijmegen, The Netherlands
| | - Jose Luis Gómez-Skarmeta
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas and Universidad Pablo de Olavide, Carretera de Utrera Km1, 41013 Sevilla, Spain
| | - Hendrik G. Stunnenberg
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, 6500 Nijmegen, The Netherlands
| | - Peter L. Jones
- Department of Cell and Developmental Biology, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA
| | - Gert Jan C. Veenstra
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, 6500 Nijmegen, The Netherlands
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32
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Vignoli A, Fabio RA, La Briola F, Giannatiempo S, Antonietti A, Maggiolini S, Canevini MP. Correlations between neurophysiological, behavioral, and cognitive function in Rett syndrome. Epilepsy Behav 2010; 17:489-96. [PMID: 20236870 DOI: 10.1016/j.yebeh.2010.01.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/21/2010] [Accepted: 01/24/2010] [Indexed: 11/19/2022]
Abstract
Rett syndrome, a neurodevelopmental disorder affecting mainly females, is caused by a mutation of the MeCP2 gene. Girls with Rett syndrome manifest diverse behavioral and cognitive phenotypes, and the reasons for this variability remain unknown. In addition, girls with Rett syndrome often have epileptic seizures and abnormal EEGs, the characteristics of which differ with the patient. The aim of the study was to verify if neurophysiological and epileptological characteristics could be correlated with cognitive measures, obtained using eye tracker technology, and behavioral scores (Vineland Adaptive Behavior Scales and Rett Assessment Rating Scale) in 18 patients with Rett syndrome (mean age 13.7 years) at clinical stages III and IV. Age at epilepsy onset and seizure frequency were strictly correlated with neuropsychological outcome, as were EEG stage and distribution of paroxysmal abnormalities. Our findings demonstrate that neurophysiological features should be considered prognostic of cognitive and behavioral outcome in the clinical management of Rett syndrome.
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Affiliation(s)
- Aglaia Vignoli
- Centro Epilessia, Azienda Ospedaliera San Paolo, Università degli Studi di Milano, Milan, Italy.
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Kernohan KD, Jiang Y, Tremblay DC, Bonvissuto AC, Eubanks JH, Mann MRW, Bérubé NG. ATRX partners with cohesin and MeCP2 and contributes to developmental silencing of imprinted genes in the brain. Epigenomics 2010; 2:743-63. [PMID: 20159591 DOI: 10.2217/epi.10.61] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Human developmental disorders caused by chromatin dysfunction often display overlapping clinical manifestations, such as cognitive deficits, but the underlying molecular links are poorly defined. Here, we show that ATRX, MeCP2, and cohesin, chromatin regulators implicated in ATR-X, RTT, and CdLS syndromes, respectively, interact in the brain and colocalize at the H19 imprinting control region (ICR) with preferential binding on the maternal allele. Importantly, we show that ATRX loss of function alters enrichment of cohesin, CTCF, and histone modifications at the H19 ICR, without affecting DNA methylation on the paternal allele. ATRX also affects cohesin, CTCF, and MeCP2 occupancy within the Gtl2/Dlk1 imprinted domain. Finally, we show that loss of ATRX interferes with the postnatal silencing of the maternal H19 gene along with a larger network of imprinted genes. We propose that ATRX, cohesin, and MeCP2 cooperate to silence a subset of imprinted genes in the postnatal mouse brain.
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Affiliation(s)
- Kristin D Kernohan
- Department of Paediatrics, 800 Commissioners Road East, London, ON N6C 2V5, Canada
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34
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MacDonald JL, Roskams AJ. Epigenetic regulation of nervous system development by DNA methylation and histone deacetylation. Prog Neurobiol 2009; 88:170-83. [PMID: 19554713 DOI: 10.1016/j.pneurobio.2009.04.002] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Alterations in the epigenetic modulation of gene expression have been implicated in several developmental disorders, cancer, and recently, in a variety of mental retardation and complex psychiatric disorders. A great deal of effort is now being focused on why the nervous system may be susceptible to shifts in activity of epigenetic modifiers. The answer may simply be that the mammalian nervous system must first produce the most complex degree of developmental patterning in biology and hardwire cells functionally in place postnatally, while still allowing for significant plasticity in order for the brain to respond to a rapidly changing environment. DNA methylation and histone deacetylation are two major epigenetic modifications that contribute to the stability of gene expression states. Perturbing DNA methylation, or disrupting the downstream response to DNA methylation - methyl-CpG-binding domain proteins (MBDs) and histone deacetylases (HDACs) - by genetic or pharmacological means, has revealed a critical requirement for epigenetic regulation in brain development, learning, and mature nervous system stability, and has identified the first distinct gene sets that are epigenetically regulated within the nervous system. Epigenetically modifying chromatin structure in response to different stimuli appears to be an ideal mechanism to generate continuous cellular diversity and coordinate shifts in gene expression at successive stages of brain development - all the way from deciding which kind of a neuron to generate, through to how many synapses a neuron can support. Here, we review the evidence supporting a role for DNA methylation and histone deacetylation in nervous system development and mature function, and present a basis from which to understand how the clinical use of HDAC inhibitors may impact nervous system function.
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Affiliation(s)
- Jessica L MacDonald
- Life Sciences Institute, Department of Zoology, University of British Columbia, BC, V6T 1Z3, Vancouver, Canada
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35
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A common MECP2 haplotype associates with reduced cortical surface area in humans in two independent populations. Proc Natl Acad Sci U S A 2009; 106:15483-8. [PMID: 19717458 DOI: 10.1073/pnas.0901866106] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The gene MECP2 is a well-known determinant of brain structure. Mutations in the MECP2 protein cause microencephalopathy and are associated with several neurodevelopmental disorders that affect both brain morphology and cognition. Although mutations in MECP2 result in severe neurological phenotypes, the effect of common variation in this genetic region is unknown. We find that common sequence variations in a region in and around MECP2 show association with structural brain size measures in 2 independent cohorts, a discovery sample from the Thematic Organized Psychosis research group, and a replication sample from the Alzheimer's Disease Neuroimaging Initiative. The most statistically significant replicated association (P < 0.025 in both cohorts) involved the minor allele of SNP rs2239464 with reduced cortical surface area, and the finding was specific to male gender in both populations. Variations in the MECP2 region were associated with cortical surface area but not cortical thickness. Secondary analysis showed that this allele was also associated with reduced surface area in specific cortical regions (cuneus, fusiform gyrus, pars triangularis) in both populations.
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36
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Jacob FD, Ramaswamy V, Andersen J, Bolduc FV. Atypical Rett syndrome with selective FOXG1 deletion detected by comparative genomic hybridization: case report and review of literature. Eur J Hum Genet 2009; 17:1577-81. [PMID: 19623215 DOI: 10.1038/ejhg.2009.95] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Rett syndrome is a severe neurodegenerative disorder characterized by acquired microcephaly, communication dysfunction, psychomotor regression, seizures and stereotypical hand movements. Mutations in methyl CpG binding protein 2 (MECP2) are identified in most patients with classic Rett syndrome. Genetic studies in patients with a Rett variant have expanded the spectrum of underlying genetic etiologies. Recently, a deletion encompassing several genes in the long arm of chromosome 14 has been associated with the congenital Rett-syndrome phenotype. Using array-based comparative genomic hybridization, we identified a 3-year-old female with a Rett-like syndrome carrying a de novo single-gene deletion of FOXG1. Her presentation included intellectual disability, epilepsy and a Rett-like phenotype. The variant features included microcephaly at birth and prominent synophrys. Our results confirm that congenital Rett syndrome can be caused by copy-number variation in FOXG1 and expand the clinical phenotypic spectrum of FOXG1 defect in humans.
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Thambirajah AA, Eubanks JH, Ausió J. MeCP2 post-translational regulation through PEST domains: two novel hypotheses: potential relevance and implications for Rett syndrome. Bioessays 2009; 31:561-9. [PMID: 19319913 DOI: 10.1002/bies.200800220] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mutations in the methyl-CpG-binding protein 2 (MeCP2) cause Rett syndrome, a severe neurodevelopmental disease associated with ataxia and other post-natal symptoms similar to autism. Much research interest has focussed on the implications of MeCP2 in disease and neuron physiology. However, little or no attention has been paid to how MeCP2 turnover is regulated. The post-translational control of MeCP2 is of critical importance, especially as subtle increases or decreases in MeCP2 amounts can affect neuron morphology and function. The latter point is of particular importance for gene therapeutic approaches in which exogenous wild-type MeCP2 is being introduced into diseased neurons. Further to this, we propose two hypotheses. The first hypothesis discusses the poly-ubiquitin-mediated post-translational regulation of MeCP2 through its two PEST domains. The second hypothesis explores the use of histone deacetylase inhibitors to modulate the amounts of MeCP2 expressed in conjunction with the aforementioned therapeutic approaches.
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Affiliation(s)
- Anita A Thambirajah
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
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Ogier M, Katz DM. Breathing dysfunction in Rett syndrome: understanding epigenetic regulation of the respiratory network. Respir Physiol Neurobiol 2009; 164:55-63. [PMID: 18534925 DOI: 10.1016/j.resp.2008.04.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Revised: 04/09/2008] [Accepted: 04/10/2008] [Indexed: 11/17/2022]
Abstract
Severely arrhythmic breathing is a hallmark of Rett syndrome (RTT) and profoundly affects quality of life for patients and their families. The last decade has seen the identification of the disease-causing gene, methyl-CpG-binding protein 2 (Mecp2) and the development of mouse models that phenocopy many aspects of the human syndrome, including breathing dysfunction. Recent studies have begun to characterize the breathing phenotype of Mecp2 mutant mice and to define underlying electrophysiological and neurochemical deficits. The picture that is emerging is one of defects in synaptic transmission throughout the brainstem respiratory network associated with abnormal expression in several neurochemical signaling systems, including brain-derived neurotrophic factor (BDNF), biogenic amines and gamma-amino-butyric acid (GABA). Based on such findings, potential therapeutic strategies aimed at improving breathing by targeting deficits in neurochemical signaling are being explored. This review details our current understanding of respiratory dysfunction and underlying mechanisms in RTT with a particular focus on insights gained from mouse models.
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Affiliation(s)
- Michael Ogier
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106-4975, USA
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Swanberg SE, Nagarajan RP, Peddada S, Yasui DH, LaSalle JM. Reciprocal co-regulation of EGR2 and MECP2 is disrupted in Rett syndrome and autism. Hum Mol Genet 2008; 18:525-34. [PMID: 19000991 PMCID: PMC2638799 DOI: 10.1093/hmg/ddn380] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mutations in MECP2, encoding methyl-CpG-binding protein 2 (MeCP2), cause the neurodevelopmental disorder Rett syndrome (RTT). Although MECP2 mutations are rare in idiopathic autism, reduced MeCP2 levels are common in autism cortex. MeCP2 is critical for postnatal neuronal maturation and a modulator of activity-dependent genes such as Bdnf (brain-derived neurotropic factor) and JUNB. The activity-dependent early growth response gene 2 (EGR2), required for both early hindbrain development and mature neuronal function, has predicted binding sites in the promoters of several neurologically relevant genes including MECP2. Conversely, MeCP2 family members MBD1, MBD2 and MBD4 bind a methylated CpG island in an enhancer region located in EGR2 intron 1. This study was designed to test the hypothesis that MECP2 and EGR2 regulate each other’s expression during neuronal maturation in postnatal brain development. Chromatin immunoprecipitation analysis showed EGR2 binding to the MECP2 promoter and MeCP2 binding to the enhancer region in EGR2 intron 1. Reduction in EGR2 and MeCP2 levels in cultured human neuroblastoma cells by RNA interference reciprocally reduced expression of both EGR2 and MECP2 and their protein products. Consistent with a role of MeCP2 in enhancing EGR2, Mecp2-deficient mouse cortex samples showed significantly reduced EGR2 by quantitative immunofluorescence. Furthermore, MeCP2 and EGR2 show coordinately increased levels during postnatal development of both mouse and human cortex. In contrast to age-matched Controls, RTT and autism postmortem cortex samples showed significant reduction in EGR2. Together, these data support a role of dysregulation of an activity-dependent EGR2/MeCP2 pathway in RTT and autism.
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Affiliation(s)
- Susan E Swanberg
- Department of Medical Microbiology and Immunology, Rowe Program in Human Genetics, School of Medicine, University of California, Davis, CA 95616, USA
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Mellström B, Savignac M, Gomez-Villafuertes R, Naranjo JR. Ca2+-Operated Transcriptional Networks: Molecular Mechanisms and In Vivo Models. Physiol Rev 2008; 88:421-49. [DOI: 10.1152/physrev.00041.2005] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Calcium is the most universal signal used by living organisms to convey information to many different cellular processes. In this review we present well-known and recently identified proteins that sense and decode the calcium signal and are key elements in the nucleus to regulate the activity of various transcriptional networks. When possible, the review also presents in vivo models in which the genes encoding these calcium sensors-transducers have been modified, to emphasize the critical role of these Ca2+-operated mechanisms in many physiological functions.
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Kumar A, Kamboj S, Malone BM, Kudo S, Twiss JL, Czymmek KJ, LaSalle JM, Schanen NC. Analysis of protein domains and Rett syndrome mutations indicate that multiple regions influence chromatin-binding dynamics of the chromatin-associated protein MECP2 in vivo. J Cell Sci 2008; 121:1128-37. [PMID: 18334558 DOI: 10.1242/jcs.016865] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The methyl-CpG-binding protein 2 (MECP2) serves both organizational and transcriptional functions in the nucleus, with two well-characterized domains integrally related to these functions. The recognition of methylated CpG dinucleotides is accomplished by the methyl-binding domain (MBD), and the transcriptional repression domain (TRD) facilitates protein-protein interactions with chromatin remodeling proteins. For each known function of MECP2, chromatin binding is a crucial activity. Here, we apply photobleaching strategies within the nucleus using domain-deleted MECP2 proteins as well as naturally occurring point mutations identified in individuals with the neurodevelopmental disorder Rett syndrome (RTT). These studies reveal that MECP2 is transiently associated with chromatin in vivo and confirm a central role for the MBD in directing the protein to heterochromatin. In addition, we report for the first time that the small region between the MBD and the TRD, known as the interdomain region (ID), stabilizes chromatin binding by MECP2 independently of the MBD. The TRD of MECP2 also contributes towards chromatin binding, whereas the N- and C-termini do not. Some common RTT missense and nonsense mutations significantly affect binding kinetics, suggesting that alterations in chromatin binding can result in protein dysfunction and hence a disease phenotype.
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Affiliation(s)
- Asmita Kumar
- Nemours Biomedical Research, Alfred I duPont Hospital for Children, Wilmington, DE 19803, USA
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RNAi‐induced down‐regulation of
Mecp2
expression in the rat brain. Int J Dev Neurosci 2008; 26:457-65. [DOI: 10.1016/j.ijdevneu.2008.02.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 02/26/2008] [Accepted: 02/26/2008] [Indexed: 01/08/2023] Open
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Abstract
Autism is a neurodevelopmental syndrome with markedly high heritability. The diagnostic indicators of autism are core behavioral symptoms, rather than definitive neuropathological markers. Etiology is thought to involve complex, multigenic interactions and possible environmental contributions. In this review, we focus on genetic pathways with multiple members represented in autism candidate gene lists. Many of these pathways can also be impinged upon by environmental risk factors associated with the disorder. The mouse model system provides a method to experimentally manipulate candidate genes for autism susceptibility, and to use environmental challenges to drive aberrant gene expression and cell pathology early in development. Mouse models for fragile X syndrome, Rett syndrome and other disorders associated with autistic-like behavior have elucidated neuropathology that might underlie the autism phenotype, including abnormalities in synaptic plasticity. Mouse models have also been used to investigate the effects of alterations in signaling pathways on neuronal migration, neurotransmission and brain anatomy, relevant to findings in autistic populations. Advances have included the evaluation of mouse models with behavioral assays designed to reflect disease symptoms, including impaired social interaction, communication deficits and repetitive behaviors, and the symptom onset during the neonatal period. Research focusing on the effect of gene-by-gene interactions or genetic susceptibility to detrimental environmental challenges may further understanding of the complex etiology for autism.
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Affiliation(s)
- S S Moy
- Neurodevelopmental Disorders Research Center, Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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High levels of MeCP2 depress MHC class I expression in neuronal cells. PLoS One 2007; 2:e1354. [PMID: 18159237 PMCID: PMC2131781 DOI: 10.1371/journal.pone.0001354] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 11/29/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The expression of MHC class I genes is repressed in mature neurons. The molecular basis of this regulation is poorly understood, but the genes are particularly rich in CpG islands. MeCP2 is a transcriptional repressor that binds to methylated CpG dinucleotides; mutations in this protein also cause the neurodevelopmental disease called Rett syndrome. Because MHC class I molecules play a role in neuronal connectivity, we hypothesised that MeCP2 might repress MHC class I expression in the CNS and that this might play a role in the pathology of Rett syndrome. METHODOLOGY We show here that transiently transfected cells expressing high levels of MeCP2 specifically downregulate cell-surface expression of MHC class I molecules in the neuronal cell line N2A and they prevent the induction of MHC class I expression in response to interferon in these cells, supporting our first hypothesis. Surprisingly, however, overexpression of the mutated forms of MeCP2 that cause Rett syndrome had a similar effect on MHC class I expression as the wild-type protein. Immunohistological analyses of brain slices from MECP2 knockout mice (the MeCP2(tm1.1Bird) strain) demonstrated a small but reproducible increase in MHC class I when compared to their wild type littermates, but we found no difference in MHC class I expression in primary cultures of mixed glial cells (mainly neurons and astrocytes) from the knockout and wild-type mice. CONCLUSION These data suggest that high levels of MeCP2, such as those found in mature neurons, may contribute to the repression of MHC expression, but we find no evidence that MeCP2 regulation of MHC class I is important for the pathogenesis of Rett syndrome.
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Integrated epigenomic analyses of neuronal MeCP2 reveal a role for long-range interaction with active genes. Proc Natl Acad Sci U S A 2007; 104:19416-21. [PMID: 18042715 DOI: 10.1073/pnas.0707442104] [Citation(s) in RCA: 284] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in MECP2 cause the autism-spectrum disorder Rett syndrome. MeCP2 is predicted to bind to methylated promoters and silence transcription. However, the first large-scale mapping of neuronal MeCP2-binding sites on 26.3 Mb of imprinted and nonimprinted loci revealed that 59% of MeCP2-binding sites are outside of genes and that only 6% are in CpG islands. Integrated genome-wide promoter analysis of MeCP2 binding, CpG methylation, and gene expression revealed that 63% of MeCP2-bound promoters are actively expressed and that only 6% are highly methylated. These results indicate that the primary function of MeCP2 is not the silencing of methylated promoters.
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Wang Z, Du Q, Wang F, Xu Q, Liu Z, Li B, Wang A, Wang Y. Large scale analysis of genes contributing to the herbal preparation dependent hippocampal plasticity in postischemic rehabilitation. Vascul Pharmacol 2007; 47:319-27. [PMID: 17945543 DOI: 10.1016/j.vph.2007.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2007] [Accepted: 09/07/2007] [Indexed: 10/22/2022]
Abstract
Herbal preparations can affect the expression of many genes involved in the ischemic process. These genes have been providing insights into the molecular basis of brain plasticity in stroke rehabilitation. However, the extent of plasticity has not been investigated using a chemogenomic approach. A herbal preparation (270 mg/kg) used to treat ischemic mice for 45 days after global ischemia resulted in a significant decrease in infarct volume and neurological score compared with that of vehicle. This effect was characterized by investigating chemical genomic profiles of the mouse hippocampus with a cDNA microarray containing 1176 known genes. Treatment with the herbal preparation reversed the expression of 46 genes out of 100 genes altered in untreated ischemic mouse hippocampus. These data indicated that more genes were upregulated (60.78%) than downregulated (30.61%), and only 46 genes (46%) appear to be prime targets for therapeutic intervention in ischemia. The altered genes can be classified into seven groups, including signal transduction (12 genes, 27%), oncogene (8 genes, 17%), and transcriptional regulation (7 genes, 15%). Such multiple plasticity of expression could be considered as the beneficial role of this herbal preparation in stroke rehabilitation. Changes in gene expression of nuclear factor of activated T cells, 14-3-3 eta, and beta-arrestin suggest a potential role for the immune system in this plasticity. Brain plasticity originates from a balance of up and downregulated genes (Yin and Yang), and reversal of gene expression in multiple pathways indicates that a complex signaling network may be constructed and investigated further.
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Affiliation(s)
- Zhong Wang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, 18 Baixincang, Dongzhimennei, Beijing 100700, China.
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Stearns NA, Schaevitz LR, Bowling H, Nag N, Berger UV, Berger-Sweeney J. Behavioral and anatomical abnormalities in Mecp2 mutant mice: a model for Rett syndrome. Neuroscience 2007; 146:907-21. [PMID: 17383101 DOI: 10.1016/j.neuroscience.2007.02.009] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 02/09/2007] [Accepted: 02/13/2007] [Indexed: 11/30/2022]
Abstract
Over 90% of Rett syndrome (RTT) cases have a mutation in the X-linked gene encoding methyl CpG binding-protein 2 (MeCP2). A mouse model that reprises clinical manifestations of the disease would be valuable for examining disease mechanisms. Here, we characterize physical and behavioral measures, as well as brain region volumes in young adult mice that have mutations in mouse methyl CpG binding-protein 2 gene (Mecp2) to serve as a baseline for other studies. Hemizygous males, which produce no functional protein, exhibit hypoactivity and abnormalities in locomotion, stereotypies, and anxiety reminiscent of the clinical condition. The mutant males also exhibit cognitive deficits in fear conditioning and object recognition relative to wildtypes. Volumetric analyses of male brains revealed a 25% reduction in whole brain volume in mutants relative to wildtypes; regional differences were also apparent. Mutants had decreased volumes in three specific brain regions: the amygdala (39%), hippocampus (21%), and striatum (29%). Heterozygous females, which produce varying amounts of functional protein, displayed a less severe behavioral phenotype. The mutant females exhibit abnormalities in locomotion, anxiety measures, and cognitive deficits in object recognition in an open field. This study provides the first evidence that the abnormal motor and cognitive behavioral phenotype in Mecp2 mice is consistent with specific volume reductions in brain regions associated with these behaviors, and shows how these data parallel the human condition. The Mecp2 mutant mice provide a very good model in which to examine molecular and behavioral mechanisms, as well as potential therapeutic interventions in RTT.
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Affiliation(s)
- N A Stearns
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA 02481, USA
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Petel-Galil Y, Benteer B, Galil YP, Zeev BB, Greenbaum I, Vecsler M, Goldman B, Lohi H, Minassian BA, Gak E. Comprehensive diagnosis of Rett's syndrome relying on genetic, epigenetic and expression evidence of deficiency of the methyl-CpG-binding protein 2 gene: study of a cohort of Israeli patients. J Med Genet 2006; 43:e56. [PMID: 17142618 PMCID: PMC2563193 DOI: 10.1136/jmg.2006.041285] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations. OBJECTIVE AND METHODS To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays. RESULTS AND CONCLUSION A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.
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Moretti P, Zoghbi HY. MeCP2 dysfunction in Rett syndrome and related disorders. Curr Opin Genet Dev 2006; 16:276-81. [PMID: 16647848 DOI: 10.1016/j.gde.2006.04.009] [Citation(s) in RCA: 223] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 04/18/2006] [Indexed: 01/28/2023]
Abstract
Rett syndrome, a neurodevelopmental disorder caused by mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2), is a leading cause of mental retardation with autistic features in females. MECP2 mutations have also been identified in individuals with a variety of clinical syndromes, including mild learning-disability in females, neonatal encephalopathy in males, and psychiatric disorders, autism and X-linked mental retardation in both males and females. Furthermore, MECP2 duplications have been shown to cause a progressive postnatal neurological disorder. MeCP2 is a transcriptional repressor that binds to methylated CpG dinucleotides flanked by AT-rich segments and recruits a co-repressor complex, thereby altering chromatin structure. Subtle gene expression changes have been identified in Rett patients and mouse models; however, MeCP2 dysfunction has also been shown to cause abnormalities of RNA splicing, suggesting a complex molecular pathogenesis. Discovering which genes are misregulated in the absence of functional MeCP2 and demonstrating their role in causing neuronal dysfunction and disease manifestations are challenging but important steps for understanding the pathogenesis of Rett syndrome and related disorders.
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Affiliation(s)
- Paolo Moretti
- Baylor College of Medicine, One Baylor Plaza, T807, Mail Stop 225, Houston, TX 77030, USA
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