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Kupke J, Klimmt J, Mudlaff F, Schwab M, Lutsik P, Plass C, Sticht C, Oliveira AMM. Dnmt3a1 regulates hippocampus-dependent memory via the downstream target Nrp1. Neuropsychopharmacology 2024:10.1038/s41386-024-01843-0. [PMID: 38499720 DOI: 10.1038/s41386-024-01843-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 02/04/2024] [Accepted: 03/04/2024] [Indexed: 03/20/2024]
Abstract
Epigenetic factors are well-established players in memory formation. Specifically, DNA methylation is necessary for the formation of long-term memory in multiple brain regions including the hippocampus. Despite the demonstrated role of DNA methyltransferases (Dnmts) in memory formation, it is unclear whether individual Dnmts have unique or redundant functions in long-term memory formation. Furthermore, the downstream processes controlled by Dnmts during memory consolidation have not been investigated. In this study, we demonstrated that Dnmt3a1, the predominant Dnmt in the adult brain, is required for long-term spatial object recognition and contextual fear memory. Using RNA sequencing, we identified an activity-regulated Dnmt3a1-dependent genomic program in which several genes were associated with functional and structural plasticity. Furthermore, we found that some of the identified genes are selectively dependent on Dnmt3a1, but not its isoform Dnmt3a2. Specifically, we identified Neuropilin 1 (Nrp1) as a downstream target of Dnmt3a1 and further demonstrated the involvement of Nrp1 in hippocampus-dependent memory formation. Importantly, we found that Dnmt3a1 regulates hippocampus-dependent memory via Nrp1. In contrast, Nrp1 overexpression did not rescue memory impairments triggered by reduced Dnmt3a2 levels. Taken together, our study uncovered a Dnmt3a-isoform-specific mechanism in memory formation, identified a novel regulator of memory, and further highlighted the complex and highly regulated functions of distinct epigenetic regulators in brain function.
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Affiliation(s)
- Janina Kupke
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, the Netherlands
| | - Julien Klimmt
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany
- Institute for Stroke and Dementia Research, University Hospital, Ludwig-Maximilians-University Munich, 81377, Munich, Germany
| | - Franziska Mudlaff
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3A 2B4, Canada
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, Montreal, QC, H3G 1A4, Canada
| | - Maximilian Schwab
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany
- Department of Medical Oncology, National Center for Tumor Diseases (NCT) Heidelberg, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Pavlo Lutsik
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Department of Oncology, KU Leuven, 3000, Leuven, Belgium
| | - Christoph Plass
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Carsten Sticht
- Next Generation Sequencing Core Facility, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Ana M M Oliveira
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany.
- Department of Molecular and Cellular Cognition Research, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany.
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2
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Furley K, Mehra C, Goin-Kochel RP, Fahey MC, Hunter MF, Williams K, Absoud M. Developmental regression in children: Current and future directions. Cortex 2023; 169:5-17. [PMID: 37839389 DOI: 10.1016/j.cortex.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/20/2023] [Accepted: 09/20/2023] [Indexed: 10/17/2023]
Abstract
Developmental regression describes when a child loses previously established skills, such as the ability to speak words and is most recognised in neurodevelopmental conditions including Autism; Developmental Epileptic Encephalopathies, such as Landau Kleffner syndrome, and genetic conditions such as Rett syndrome and Phelan McDermid syndrome. Although studies have reported developmental regression for over 100 years, there remain significant knowledge gaps within and between conditions that feature developmental regression. The certainty of evidence from earlier work has been limited by condition-specific studies, retrospective methodology, and inconsistency in the definitions and measures used for classification. Given prior limitations in the field, there is a paucity of knowledge about neurocognitive mechanisms, trajectories and outcomes for children with developmental regression, and their families. Here we provide a comprehensive overview, synthesise key definitions, clinical measures, and aetiological clues associated with developmental regression and discuss impacts on caregiver physical and mental health to clarify challenges and highlight future directions in the field.
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Affiliation(s)
- Kirsten Furley
- Monash Children's Hospital, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia.
| | - Chirag Mehra
- Children's Neurosciences, Evelina London Children's Hospital, St Thomas' Hospital, London, UK; Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Robin P Goin-Kochel
- Department of Pediatrics, Baylor College of Medicine, United States; Meyer Center for Developmental Pediatrics & Autism, Texas Children's Hospital, United States
| | - Michael C Fahey
- Monash Children's Hospital, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia
| | - Matthew F Hunter
- Monash Children's Hospital, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia
| | - Katrina Williams
- Monash Children's Hospital, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia
| | - Michael Absoud
- Children's Neurosciences, Evelina London Children's Hospital, St Thomas' Hospital, London, UK; Department of Women and Children's Health, King's College London, London, UK.
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3
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Motosugi N, Sugiyama A, Okada C, Otomo A, Umezawa A, Akutsu H, Hadano S, Fukuda A. De-erosion of X chromosome dosage compensation by the editing of XIST regulatory regions restores the differentiation potential in hPSCs. CELL REPORTS METHODS 2022; 2:100352. [PMID: 36590687 PMCID: PMC9795333 DOI: 10.1016/j.crmeth.2022.100352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/29/2022] [Accepted: 10/28/2022] [Indexed: 12/02/2022]
Abstract
Human pluripotent stem cells (hPSCs) regularly and irreversibly show the erosion of X chromosome inactivation (XCI) by long non-coding RNA (lncRNA) XIST silencing, causing challenges in various applications of female hPSCs. Here, we report reliable methods to reactivate XIST with monoallelic expression in female hPSCs. Surprisingly, we find that the editing of XIST regulatory regions by Cas9-mediated non-homologous end joining is sufficient for the reactivation of XIST by endogenous systems. Proliferated hPSCs with XIST reactivation show XCI from an eroded X chromosome, suggesting that hPSCs with normal dosage compensation might lead to a growth advantage. Furthermore, the use of targeting vectors, including the XIST regulatory region sequences and selection cassette, enables XIST reactivation in hPSCs with high efficiency. XIST-reactivated hPSCs can show the restoration of differentiation potential. Thus, our findings demonstrate that XIST re-expression is a beneficial method to maximize the use of female hPSCs in various applications, such as proper disease modeling.
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Affiliation(s)
- Nami Motosugi
- Department of Molecular Life Sciences, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Akiko Sugiyama
- Department of Molecular Life Sciences, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Chisa Okada
- Support Center for Medical Research and Education, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Asako Otomo
- Department of Molecular Life Sciences, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
- The Institute of Medical Sciences, Tokai University, Isehara, Kanagawa, Japan
- Micro/Nano Technology Center, Tokai University, Hiratsuka, Kanagawa, Japan
| | - Akihiro Umezawa
- Center for Regenerative Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Hidenori Akutsu
- Center for Regenerative Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Shinji Hadano
- Department of Molecular Life Sciences, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
- The Institute of Medical Sciences, Tokai University, Isehara, Kanagawa, Japan
- Micro/Nano Technology Center, Tokai University, Hiratsuka, Kanagawa, Japan
| | - Atsushi Fukuda
- Department of Molecular Life Sciences, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
- The Institute of Medical Sciences, Tokai University, Isehara, Kanagawa, Japan
- Micro/Nano Technology Center, Tokai University, Hiratsuka, Kanagawa, Japan
- Center for Regenerative Medicine, National Center for Child Health and Development, Tokyo, Japan
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4
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Baroncelli L, Auel S, Rinne L, Schuster AK, Brand V, Kempkes B, Dietrich K, Müller M. Oral Feeding of an Antioxidant Cocktail as a Therapeutic Strategy in a Mouse Model of Rett Syndrome: Merits and Limitations of Long-Term Treatment. Antioxidants (Basel) 2022; 11:antiox11071406. [PMID: 35883897 PMCID: PMC9311910 DOI: 10.3390/antiox11071406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 02/01/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that typically arises from spontaneous germline mutations in the X-chromosomal methyl-CpG binding protein 2 (MECP2) gene. For the first 6–18 months of life, the development of the mostly female patients appears normal. Subsequently, cognitive impairment, motor disturbances, hand stereotypies, epilepsy, and irregular breathing manifest, with previously learned skills being lost. Early mitochondrial impairment and a systemic oxidative burden are part of the complex pathogenesis, and contribute to disease progression. Accordingly, partial therapeutic merits of redox-stabilizing and antioxidant (AO) treatments were reported in RTT patients and Mecp2-mutant mice. Pursuing these findings, we conducted a full preclinical trial on male and female mice to define the therapeutic value of an orally administered AO cocktail composed of vitamin E, N-acetylcysteine, and α-lipoic acid. AO treatment ameliorated some of the microcephaly-related aspects. Moreover, the reduced growth, lowered blood glucose levels, and the hippocampal synaptic plasticity of Mecp2−/y mice improved. However, the first-time detected intensified oxidative DNA damage in Mecp2-mutant cortex persisted. The behavioral performance, breathing regularity, and life expectancy of Mecp2-mutant mice did not improve upon AO treatment. Long-term-treated Mecp2+/− mice eventually became obese. In conclusion, the AO cocktail ameliorated a subset of symptoms of the complex RTT-related phenotype, thereby further confirming the potential merits of AO-based pharmacotherapies. Yet, it also became evident that long-term AO treatment may lose efficacy and even aggravate the metabolic disturbances in RTT. This emphasizes the importance of a constantly well-balanced redox balance for systemic well-being.
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Affiliation(s)
- Laura Baroncelli
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
- Institute of Neuroscience, National Research Council (CNR), via Giuseppe Moruzzi 1, I-56124 Pisa, Italy
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Viale del Tirreno 331, I-56128 Pisa, Italy
| | - Stefanie Auel
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Lena Rinne
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Ann-Kathrin Schuster
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Victoria Brand
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Belinda Kempkes
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Katharina Dietrich
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Michael Müller
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
- Correspondence: ; Tel.: +49-551-39-22933
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5
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The Role of Transposable Elements of the Human Genome in Neuronal Function and Pathology. Int J Mol Sci 2022; 23:ijms23105847. [PMID: 35628657 PMCID: PMC9148063 DOI: 10.3390/ijms23105847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 12/13/2022] Open
Abstract
Transposable elements (TEs) have been extensively studied for decades. In recent years, the introduction of whole-genome and whole-transcriptome approaches, as well as single-cell resolution techniques, provided a breakthrough that uncovered TE involvement in host gene expression regulation underlying multiple normal and pathological processes. Of particular interest is increased TE activity in neuronal tissue, and specifically in the hippocampus, that was repeatedly demonstrated in multiple experiments. On the other hand, numerous neuropathologies are associated with TE dysregulation. Here, we provide a comprehensive review of literature about the role of TEs in neurons published over the last three decades. The first chapter of the present review describes known mechanisms of TE interaction with host genomes in general, with the focus on mammalian and human TEs; the second chapter provides examples of TE exaptation in normal neuronal tissue, including TE involvement in neuronal differentiation and plasticity; and the last chapter lists TE-related neuropathologies. We sought to provide specific molecular mechanisms of TE involvement in neuron-specific processes whenever possible; however, in many cases, only phenomenological reports were available. This underscores the importance of further studies in this area.
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6
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Changes in the Cerebrospinal Fluid and Plasma Lipidome in Patients with Rett Syndrome. Metabolites 2022; 12:metabo12040291. [PMID: 35448478 PMCID: PMC9026385 DOI: 10.3390/metabo12040291] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 01/27/2023] Open
Abstract
Rett syndrome (RTT) is defined as a rare disease caused by mutations of the methyl-CpG binding protein 2 (MECP2). It is one of the most common causes of genetic mental retardation in girls, characterized by normal early psychomotor development, followed by severe neurologic regression. Hitherto, RTT lacks a specific biomarker, but altered lipid homeostasis has been found in RTT model mice as well as in RTT patients. We performed LC-MS/MS lipidomics analysis to investigate the cerebrospinal fluid (CSF) and plasma composition of patients with RTT for biochemical variations compared to healthy controls. In all seven RTT patients, we found decreased CSF cholesterol levels compared to age-matched controls (n = 13), whereas plasma cholesterol levels were within the normal range in all 13 RTT patients compared to 18 controls. Levels of phospholipid (PL) and sphingomyelin (SM) species were decreased in CSF of RTT patients, whereas the lipidomics profile of plasma samples was unaltered in RTT patients compared to healthy controls. This study shows that the CSF lipidomics profile is altered in RTT, which is the basis for future (functional) studies to validate selected lipid species as CSF biomarkers for RTT.
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7
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A brief history of MECP2 duplication syndrome: 20-years of clinical understanding. Orphanet J Rare Dis 2022; 17:131. [PMID: 35313898 PMCID: PMC8939085 DOI: 10.1186/s13023-022-02278-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/07/2022] [Indexed: 11/10/2022] Open
Abstract
MECP2 duplication syndrome (MDS) is a rare, X-linked, neurodevelopmental disorder caused by a duplication of the methyl-CpG-binding protein 2 (MECP2) gene-a gene in which loss-of-function mutations lead to Rett syndrome (RTT). MDS has an estimated live birth prevalence in males of 1/150,000. The key features of MDS include intellectual disability, developmental delay, hypotonia, seizures, recurrent respiratory infections, gastrointestinal problems, behavioural features of autism and dysmorphic features-although these comorbidities are not yet understood with sufficient granularity. This review has covered the past two decades of MDS case studies and series since the discovery of the disorder in 1999. After comprehensively reviewing the reported characteristics, this review has identified areas of limited knowledge that we recommend may be addressed by better phenotyping this disorder through an international data collection. This endeavour would also serve to delineate the clinical overlap between MDS and RTT.
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8
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Shi D, Motamed M, Mejía-Benítez A, Li L, Lin E, Budhram D, Kaur Y, Meyre D. Genetic syndromes with diabetes: A systematic review. Obes Rev 2021; 22:e13303. [PMID: 34268868 DOI: 10.1111/obr.13303] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 01/19/2023]
Abstract
Previous reviews and clinical guidelines have identified 10-20 genetic syndromes associated with diabetes, but no systematic review has been conducted to date. We provide the first comprehensive catalog for syndromes with diabetes mellitus. We conducted a systematic review of MEDLINE, Embase, CENTRAL, PubMed, OMIM, and Orphanet databases for case reports, case series, and observational studies published between 1946 and January 15, 2020, that described diabetes mellitus in adults and children with monogenic or chromosomal syndromes. Our literature search identified 7,122 studies, of which 160 fulfilled inclusion criteria. Our analysis of these studies found 69 distinct diabetes syndromes. Thirty (43.5%) syndromes included diabetes mellitus as a cardinal clinical feature, and 56 (81.2%) were fully genetically elucidated. Sixty-three syndromes (91.3%) were described more than once in independent case reports, of which 59 (93.7%) demonstrated clinical heterogeneity. Syndromes associated with diabetes mellitus are more numerous and diverse than previously anticipated. While knowledge of the syndromes is limited by their low prevalence, future reviews will be needed as more cases are identified. The genetic etiologies of these syndromes are well elucidated and provide potential avenues for future gene identification efforts, aid in diagnosis and management, gene therapy research, and developing personalized medicine treatments.
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Affiliation(s)
- Daniel Shi
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Faculty of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Mehras Motamed
- Faculty of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Aurora Mejía-Benítez
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Leon Li
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Ethan Lin
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Dalton Budhram
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Faculty of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Yuvreet Kaur
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.,Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, and Nutrition, University Hospital of Nancy, Nancy, France.,Faculty of Medicine of Nancy INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, France
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9
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Janowski M, Milewska M, Zare P, Pękowska A. Chromatin Alterations in Neurological Disorders and Strategies of (Epi)Genome Rescue. Pharmaceuticals (Basel) 2021; 14:765. [PMID: 34451862 PMCID: PMC8399958 DOI: 10.3390/ph14080765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/23/2021] [Accepted: 07/24/2021] [Indexed: 12/26/2022] Open
Abstract
Neurological disorders (NDs) comprise a heterogeneous group of conditions that affect the function of the nervous system. Often incurable, NDs have profound and detrimental consequences on the affected individuals' lives. NDs have complex etiologies but commonly feature altered gene expression and dysfunctions of the essential chromatin-modifying factors. Hence, compounds that target DNA and histone modification pathways, the so-called epidrugs, constitute promising tools to treat NDs. Yet, targeting the entire epigenome might reveal insufficient to modify a chosen gene expression or even unnecessary and detrimental to the patients' health. New technologies hold a promise to expand the clinical toolkit in the fight against NDs. (Epi)genome engineering using designer nucleases, including CRISPR-Cas9 and TALENs, can potentially help restore the correct gene expression patterns by targeting a defined gene or pathway, both genetically and epigenetically, with minimal off-target activity. Here, we review the implication of epigenetic machinery in NDs. We outline syndromes caused by mutations in chromatin-modifying enzymes and discuss the functional consequences of mutations in regulatory DNA in NDs. We review the approaches that allow modifying the (epi)genome, including tools based on TALENs and CRISPR-Cas9 technologies, and we highlight how these new strategies could potentially change clinical practices in the treatment of NDs.
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Affiliation(s)
| | | | | | - Aleksandra Pękowska
- Dioscuri Centre for Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteur Street, 02-093 Warsaw, Poland; (M.J.); (M.M.); (P.Z.)
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10
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D'Mello SR. MECP2 and the Biology of MECP2 Duplication Syndrome. J Neurochem 2021; 159:29-60. [PMID: 33638179 DOI: 10.1111/jnc.15331] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 02/18/2021] [Indexed: 11/27/2022]
Abstract
MECP2 duplication syndrome (MDS), a rare X-linked genomic disorder affecting predominantly males, is caused by duplication of the chromosomal region containing the methyl CpG binding protein-2 (MECP2) gene, which encodes methyl-CpG-binding protein 2 (MECP2), a multi-functional protein required for proper brain development and maintenance of brain function during adulthood. Disease symptoms include severe motor and cognitive impairment, delayed or absent speech development, autistic features, seizures, ataxia, recurrent respiratory infections and shortened lifespan. The cellular and molecular mechanisms by which a relatively modest increase in MECP2 protein causes such severe disease symptoms are poorly understood and consequently there are no treatments available for this fatal disorder. This review summarizes what is known to date about the structure and complex regulation of MECP2 and its many functions in the developing and adult brain. Additionally, recent experimental findings on the cellular and molecular underpinnings of MDS based on cell culture and mouse models of the disorder are reviewed. The emerging picture from these studies is that MDS is a neurodegenerative disorder in which neurons die in specific parts of the central nervous system, including the cortex, hippocampus, cerebellum and spinal cord. Neuronal death likely results from astrocytic dysfunction, including a breakdown of glutamate homeostatic mechanisms. The role of elevations in the expression of glial acidic fibrillary protein (GFAP) in astrocytes and the microtubule-associated protein, Tau, in neurons to the pathogenesis of MDS is discussed. Lastly, potential therapeutic strategies to potentially treat MDS are discussed.
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11
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Rucco R, Bernardo P, Lardone A, Baselice F, Pesoli M, Polverino A, Bravaccio C, Granata C, Mandolesi L, Sorrentino G, Sorrentino P. Neuronal Avalanches to Study the Coordination of Large-Scale Brain Activity: Application to Rett Syndrome. Front Psychol 2020; 11:550749. [PMID: 33192799 PMCID: PMC7656905 DOI: 10.3389/fpsyg.2020.550749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 09/28/2020] [Indexed: 11/13/2022] Open
Abstract
Many complex systems, such as the brain, display large-scale coordinated interactions that create ordered patterns. Classically, such patterns have been studied using the framework of criticality, i.e., at a transition point between two qualitatively distinct patterns. This kind of system is generally characterized by a scale-invariant organization, in space and time, optimally described by a power-law distribution whose slope is quantified by an exponent α. The dynamics of these systems is characterized by alternating periods of activations, called avalanches, with quiescent periods. To maximize its efficiency, the system must find a trade-off between its stability and ease of propagation of activation, which is achieved by a branching process. It is quantified by a branching parameter σ defined as the average ratio between the number of activations in consecutive time bins. The brain is itself a complex system and its activity can be described as a series of neuronal avalanches. It is known that critical aspects of brain dynamics are modeled with a branching parameter σ = , and the neuronal avalanches distribution fits well with a power law distribution exponent α = -3/2. The aim of our work was to study a self-organized criticality system in which there was a change in neuronal circuits due to genetic causes. To this end, we have compared the characteristics of neuronal avalanches in a group of 10 patients affected by Rett syndrome, during an open-eye resting-state condition estimated using magnetoencephalography, with respect to 10 healthy subjects. The analysis was performed both in broadband and in the five canonical frequency bands. We found, for both groups, a branching parameter close to 1. In this critical condition, Rett patients show a lower distribution parameter α in the delta and broadband. These results suggest that the large-scale coordination of activity occurs to a lesser extent in RTT patients.
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Affiliation(s)
- Rosaria Rucco
- Department of Motor Sciences and Wellness, University of Naples "Parthenope," Naples, Italy.,Institute of Applied Sciences and Intelligent Systems, National Research Council (CNR), Pozzuoli, Italy
| | - Pia Bernardo
- Department of Medical and Translational Science, Child Neuropsychiatry Unit, University of Naples "Federico II," Naples, Italy.,Department of Neuroscience, Pediatric Psychiatry and Neurology, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Anna Lardone
- Department of Motor Sciences and Wellness, University of Naples "Parthenope," Naples, Italy
| | - Fabio Baselice
- Department of Engineering, University of Naples "Parthenope," Naples, Italy
| | - Matteo Pesoli
- Department of Motor Sciences and Wellness, University of Naples "Parthenope," Naples, Italy
| | | | - Carmela Bravaccio
- Department of Medical and Translational Science, Child Neuropsychiatry Unit, University of Naples "Federico II," Naples, Italy
| | - Carmine Granata
- Institute of Applied Sciences and Intelligent Systems, National Research Council (CNR), Pozzuoli, Italy
| | - Laura Mandolesi
- Department of Humanistic Studies, University of Naples "Federico II," Naples, Italy
| | - Giuseppe Sorrentino
- Department of Motor Sciences and Wellness, University of Naples "Parthenope," Naples, Italy.,Institute of Applied Sciences and Intelligent Systems, National Research Council (CNR), Pozzuoli, Italy.,Hermitage Capodimonte Hospital, Naples, Italy
| | - Pierpaolo Sorrentino
- Institute of Applied Sciences and Intelligent Systems, National Research Council (CNR), Pozzuoli, Italy.,Department of Engineering, University of Naples "Parthenope," Naples, Italy.,Institut de Neurosciences des Systèmes, Aix-Marseille Université, Marseille, France
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12
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Gomes TM, Dias da Silva D, Carmo H, Carvalho F, Silva JP. Epigenetics and the endocannabinoid system signaling: An intricate interplay modulating neurodevelopment. Pharmacol Res 2020; 162:105237. [PMID: 33053442 DOI: 10.1016/j.phrs.2020.105237] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/16/2020] [Accepted: 10/02/2020] [Indexed: 01/08/2023]
Abstract
The endocannabinoid (eCB) system is a complex system comprising endogenous cannabinoids (eCBs), their synthesis and degradation enzymes, and cannabinoid receptors. These elements crucially regulate several biological processes during neurodevelopment, such as proliferation, differentiation, and migration. Recently, eCBs were also reported to have an epigenetic action on genes that play key functions in the neurotransmitter signaling, consequently regulating their expression. In turn, epigenetic modifications (e.g. DNA methylation, histone modifications) may also modulate the function of eCB system's elements. For example, the expression of the cnr gene in the central nervous system may be epigenetically regulated (e.g. DNA methylation, histone modifications), thus altering the function of the cannabinoid receptor type-1 (CB1R). Considering the importance of the eCB system during neurodevelopment, it is thus reasonable to expect that alterations in this interaction between the eCB system and epigenetic modifications may give rise to neurodevelopmental disorders. Here, we review key concepts related to the regulation of neuronal function by the eCB system and the different types of epigenetic modifications. In particular, we focus on the mechanisms involved in the intricate interplay between both signaling systems and how they control cell fate during neurodevelopment. Noteworthy, such mechanistic understanding assumes high relevance considering the implications of the dysregulation of key neurogenic processes towards the onset of neurodevelopment-related disorders. Moreover, considering the increasing popularity of cannabis and its synthetic derivatives among young adults, it becomes of utmost importance to understand how exogenous cannabinoids may epigenetically impact neurodevelopment.
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Affiliation(s)
- Telma Marisa Gomes
- UCIBIO, REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Diana Dias da Silva
- UCIBIO, REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Helena Carmo
- UCIBIO, REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Félix Carvalho
- UCIBIO, REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
| | - João Pedro Silva
- UCIBIO, REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
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13
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Tang BL. RAB39B's role in membrane traffic, autophagy, and associated neuropathology. J Cell Physiol 2020; 236:1579-1592. [PMID: 32761840 DOI: 10.1002/jcp.29962] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/19/2020] [Accepted: 07/13/2020] [Indexed: 12/14/2022]
Abstract
Neuropathological disorders are increasingly associated with dysfunctions in neuronal membrane traffic and autophagy, with defects among members of the Rab family of small GTPases implicated. Mutations in the human Xq28 localized gene RAB39B have been associated with X-linked neurodevelopmental defects including macrocephaly, intellectual disability, autism spectrum disorder (ASD), as well as rare cases of early-onset Parkinson's disease (PD). Despite the finding that RAB39B regulates GluA2 trafficking and could thus influence synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit composition, reasons for the wide-ranging neuropathological consequences associated with RAB39B defects have been unclear. Recent studies have now unraveled possible mechanisms underlying the neuropathological roles of this brain-enriched small GTPase. Studies in RAB39B knockout mice showed that RAB39B interacts with components of Class I phosphatidylinositol-3-kinase (PI3K) signaling. In its absence, the PI3K-AKT-mechanistic target of rapamycin signaling pathway in neural progenitor cells (NPCs) is hyperactivated, which promotes NPC proliferation, leading to macrocephaly and ASD. Pertaining to early-onset PD, a complex of C9orf72, Smith-Magenis syndrome chromosome region candidate 8 and WD repeat domain 41 that functions in autophagy has been identified as a guanine nucleotide exchange factor of RAB39B. Here, recent findings that have shed light on our mechanistic understanding of RAB39B's role in neurodevelopmental and neurodegenerative pathologies are reviewed. Caveats and unanswered questions are also discussed, and future perspectives outlined.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore, Singapore
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14
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The role of neuroglia in autism spectrum disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 173:301-330. [PMID: 32711814 DOI: 10.1016/bs.pmbts.2020.04.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Neuroglia are a large class of neural cells of ectodermal (astroglia, oligodendroglia, and peripheral glial cells) and mesodermal (microglia) origin. Neuroglial cells provide homeostatic support, protection, and defense to the nervous tissue. Pathological potential of neuroglia has been acknowledged since their discovery. Research of the recent decade has shown the key role of all classes of glial cells in autism spectrum disorders (ASD), although molecular mechanisms defining glial contribution to ASD are yet to be fully characterized. This narrative conceptualizes recent findings of the broader roles of glial cells, including their active participation in the control of cerebral environment and regulation of synaptic development and scaling, highlighting their putative involvement in the etiopathogenesis of ASD.
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15
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In vitro modeling of dendritic atrophy in Rett syndrome: determinants for phenotypic drug screening in neurodevelopmental disorders. Sci Rep 2020; 10:2491. [PMID: 32051524 PMCID: PMC7016139 DOI: 10.1038/s41598-020-59268-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 01/21/2020] [Indexed: 01/16/2023] Open
Abstract
Dendritic atrophy, defined as the reduction in complexity of the neuronal arborization, is a hallmark of several neurodevelopmental disorders, including Rett Syndrome (RTT). RTT, affecting 1:10,000 girls worldwide, is mainly caused by mutations in the MECP2 gene and has no cure. We describe here an in vitro model of dendritic atrophy in Mecp2−/y mouse hippocampal primary cultures, suitable for phenotypic drug-screening. Using High-Content Imaging techniques, we systematically investigated the impact of culturing determinants on several parameters such as neuronal survival, total dendritic length, dendritic endpoints, soma size, cell clusterization, spontaneous activity. Determinants included cell-seeding density, glass or polystyrene substrates, coating with poly-Ornithine with/without Matrigel and miniaturization from 24 to 96-half surface multiwell plates. We show that in all plate-sizes at densities below 320 cells/mm2, morphological parameters remained constant while spontaneous network activity decreased according to the cell-density. Mecp2−/y neurons cultured at 160 cells/mm2 density in 96 multiwell plates, displayed significant dendritic atrophy and showed a marked increase in dendritic length following treatment with Brain-derived neurotrophic factor (BDNF) or Mirtazapine. In conclusion, we have established a phenotypic assay suitable for fast screening of hundreds of compounds, which may be extended to other neurodevelopmental diseases with dendritic atrophy.
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16
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DNA methylation directs microRNA biogenesis in mammalian cells. Nat Commun 2019; 10:5657. [PMID: 31827083 PMCID: PMC6906426 DOI: 10.1038/s41467-019-13527-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 10/28/2019] [Indexed: 12/19/2022] Open
Abstract
MicroRNA (miRNA) biogenesis initiates co-transcriptionally, but how the Microprocessor machinery pinpoints the locations of short precursor miRNA sequences within long flanking regions of the transcript is not known. Here we show that miRNA biogenesis depends on DNA methylation. When the regions flanking the miRNA coding sequence are highly methylated, the miRNAs are more highly expressed, have greater sequence conservation, and are more likely to drive cancer-related phenotypes than miRNAs encoded by unmethylated loci. We show that the removal of DNA methylation from miRNA loci leads to their downregulation. Further, we found that MeCP2 binding to methylated miRNA loci halts RNA polymerase II elongation, leading to enhanced processing of the primary miRNA by Drosha. Taken together, our data reveal that DNA methylation directly affects miRNA biogenesis.
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17
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Higgins GA, Williams AM, Ade AS, Alam HB, Athey BD. Druggable Transcriptional Networks in the Human Neurogenic Epigenome. Pharmacol Rev 2019; 71:520-538. [PMID: 31530573 PMCID: PMC6750186 DOI: 10.1124/pr.119.017681] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Chromosome conformation capture methods have revealed the dynamics of genome architecture which is spatially organized into topologically associated domains, with gene regulation mediated by enhancer-promoter pairs in chromatin space. New evidence shows that endogenous hormones and several xenobiotics act within circumscribed topological domains of the spatial genome, impacting subsets of the chromatin contacts of enhancer-gene promoter pairs in cis and trans Results from the National Institutes of Health-funded PsychENCODE project and the study of chromatin remodeling complexes have converged to provide a clearer understanding of the organization of the neurogenic epigenome in humans. Neuropsychiatric diseases, including schizophrenia, bipolar spectrum disorder, autism spectrum disorder, attention deficit hyperactivity disorder, and other neuropsychiatric disorders are significantly associated with mutations in neurogenic transcriptional networks. In this review, we have reanalyzed the results from publications of the PsychENCODE Consortium using pharmacoinformatics network analysis to better understand druggable targets that control neurogenic transcriptional networks. We found that valproic acid and other psychotropic drugs directly alter these networks, including chromatin remodeling complexes, transcription factors, and other epigenetic modifiers. We envision a new generation of CNS therapeutics targeted at neurogenic transcriptional control networks, including druggable parts of chromatin remodeling complexes and master transcription factor-controlled pharmacogenomic networks. This may provide a route to the modification of interconnected gene pathways impacted by disease in patients with neuropsychiatric and neurodegenerative disorders. Direct and indirect therapeutic strategies to modify the master regulators of neurogenic transcriptional control networks may ultimately help extend the life span of CNS neurons impacted by disease.
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Affiliation(s)
- Gerald A Higgins
- Departments of Computational Medicine and Bioinformatics (G.A.H., A.S.A., B.D.A.), Surgery (A.M.W., H.B.A.), and Psychiatry (B.D.A.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Aaron M Williams
- Departments of Computational Medicine and Bioinformatics (G.A.H., A.S.A., B.D.A.), Surgery (A.M.W., H.B.A.), and Psychiatry (B.D.A.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Alex S Ade
- Departments of Computational Medicine and Bioinformatics (G.A.H., A.S.A., B.D.A.), Surgery (A.M.W., H.B.A.), and Psychiatry (B.D.A.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Hasan B Alam
- Departments of Computational Medicine and Bioinformatics (G.A.H., A.S.A., B.D.A.), Surgery (A.M.W., H.B.A.), and Psychiatry (B.D.A.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Brian D Athey
- Departments of Computational Medicine and Bioinformatics (G.A.H., A.S.A., B.D.A.), Surgery (A.M.W., H.B.A.), and Psychiatry (B.D.A.), University of Michigan Medical School, Ann Arbor, Michigan
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18
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Roche KJ, LeBlanc JJ, Levin AR, O'Leary HM, Baczewski LM, Nelson CA. Electroencephalographic spectral power as a marker of cortical function and disease severity in girls with Rett syndrome. J Neurodev Disord 2019; 11:15. [PMID: 31362710 PMCID: PMC6668116 DOI: 10.1186/s11689-019-9275-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 07/10/2019] [Indexed: 11/17/2022] Open
Abstract
Background Rett syndrome is a neurodevelopmental disorder caused by a mutation in the X-linked MECP2 gene. Individuals with Rett syndrome typically develop normally until around 18 months of age before undergoing a developmental regression, and the disorder can lead to cognitive, motor, sensory, and autonomic dysfunction. Understanding the mechanism of developmental regression represents a unique challenge when viewed through a neuroscience lens. Are circuits that were previously established erased, and are new ones built to supplant old ones? One way to examine circuit-level changes is with the use of electroencephalography (EEG). Previous studies of the EEG in individuals with Rett syndrome have focused on morphological characteristics, but few have explored spectral power, including power as an index of brain function or disease severity. This study sought to determine if EEG power differs in girls with Rett syndrome and typically developing girls and among girls with Rett syndrome based on various clinical characteristics in order to better understand neural connectivity and cortical organization in individuals with this disorder. Methods Resting state EEG data were acquired from girls with Rett syndrome (n = 57) and typically developing children without Rett syndrome (n = 37). Clinical data were also collected for girls with Rett syndrome. EEG power across several brain regions in numerous frequency bands was then compared between girls with Rett syndrome and typically developing children and power in girls with Rett syndrome was compared based on these clinical measures. 1/ƒ slope was also compared between groups. Results Girls with Rett syndrome demonstrate significantly lower power in the middle frequency bands across multiple brain regions. Additionally, girls with Rett syndrome that are postregression demonstrate significantly higher power in the lower frequency delta and theta bands and a significantly more negative slope of the power spectrum. Increased power in these bands, as well as a more negative 1/ƒ slope, trended with lower cognitive assessment scores. Conclusions Increased power in lower frequency bands is consistent with previous studies demonstrating a “slowing” of the background EEG in Rett syndrome. This increase, particularly in the delta band, could represent abnormal cortical inhibition due to dysfunctional GABAergic signaling and could potentially be used as a marker of severity due to associations with more severe Rett syndrome phenotypes.
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Affiliation(s)
- Katherine J Roche
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Jocelyn J LeBlanc
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA.,F.M. Kirby Neurobiology Center, Neurology Department, Harvard Medical School, Boston, MA, USA
| | - April R Levin
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Heather M O'Leary
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Lauren M Baczewski
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA
| | - Charles A Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA. .,Graduate School of Education, Harvard University, Cambridge, MA, USA.
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19
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Picard N, Fagiolini M. MeCP2: an epigenetic regulator of critical periods. Curr Opin Neurobiol 2019; 59:95-101. [PMID: 31163286 DOI: 10.1016/j.conb.2019.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/10/2019] [Indexed: 01/30/2023]
Abstract
Complex adult behaviors arise from the integration of sequential and often overlapping critical periods (CPs) early in life and adolescence. These processes rely on a subtle interplay between the set of genes inherited from the parents, the surrounding environment and epigenetic regulation. Methyl-CpG-binding protein 2 (MeCP2) has been shown to recognize epigenetic states and regulate gene expression by reading methylated DNA. Here, we will review the recent findings revealing the role of MeCP2 during postnatal CPs of development using mouse models of Rett (RTT) syndrome.
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Affiliation(s)
- Nathalie Picard
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States.
| | - Michela Fagiolini
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States; International Research Center for Neurointelligence, University of Tokyo Institutes for Advanced Study, Tokyo, 113-0033, Japan.
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20
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Regression in Rett syndrome: Developmental pathways to its onset. Neurosci Biobehav Rev 2019; 98:320-332. [DOI: 10.1016/j.neubiorev.2019.01.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/24/2019] [Accepted: 01/29/2019] [Indexed: 11/18/2022]
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21
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Binder EB. [Environment and epigenetics]. DER NERVENARZT 2019; 90:107-113. [PMID: 30643952 DOI: 10.1007/s00115-018-0657-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Environmental factors are among the strongest risk factors for psychiatric disorders. Differences in exposure to such environments have been associated with lasting biological changes. In recent years epigenetic mechanisms have been brought to the forefront as central in mediating a lasting embedding of environmental risk factors. This article first summarizes the different levels of epigenetic regulation and then focuses on mechanisms transducing environmental signals into lasting epigenetic changes. This is followed by examples of how environmentally induced epigenetic changes relate to risk and resilience to psychiatric disorders and their treatment.
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Affiliation(s)
- Elisabeth B Binder
- Abteilung für translationale Forschung für Psychiatrie, Max-Planck-Institut für Psychiatrie, Kraepelinstr. 2-10, 80804, München, Deutschland. .,Dept. of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, USA.
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22
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Sakai A, Sugiyama S. Experience-dependent transcriptional regulation in juvenile brain development. Dev Growth Differ 2019; 60:473-482. [PMID: 30368782 DOI: 10.1111/dgd.12571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 09/21/2018] [Accepted: 09/21/2018] [Indexed: 12/26/2022]
Abstract
During brain development, once primary neural networks are formed, they are largely sculpted by environmental stimuli. The juvenile brain has a unique time window termed the critical period, in which neuronal circuits are remodeled by experience. Accumulating evidence indicates that abnormal rewiring of circuits in early life contributes to various neurodevelopmental disorders at later stages of life. Recent studies implicate two important aspects for activation of the critical period, both of which are experience-dependent: (a) proper excitatory/inhibitory (E/I) balance of neural circuit achieved during developmental trajectory of inhibitory interneurons, and (b) epigenetic regulation allowing flexible gene expression for neuronal plasticity. In this review, we discuss the molecular mechanisms of juvenile brain plasticity from the viewpoints of transcriptional and chromatin regulation, with a focus on Otx2 homeoprotein. Depending on experience, Otx2 is transported into cortical parvalbumin-positive interneurons (PV cells), where it induces PV cell maturation to activate the critical period. Understanding the unique behavior and function of Otx2 as a "messenger" of experience should therefore provide insights into mechanisms of juvenile brain development. Recently identified downstream targets of Otx2 suggest novel roles of Otx2 in homeostasis of PV cells, and, moreover, in regulation of chromatin state, which is important for neuronal plasticity. We further discuss epigenetic changes during postnatal brain development spanning the critical period. Different aspects of chromatin regulation may underlie experience-dependent neuronal development and plasticity.
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Affiliation(s)
- Akiko Sakai
- Laboratory of Neuronal Development, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Sayaka Sugiyama
- Laboratory of Neuronal Development, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
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23
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Oxidative Stress, Maternal Diabetes, and Autism Spectrum Disorders. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:3717215. [PMID: 30524654 PMCID: PMC6247386 DOI: 10.1155/2018/3717215] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/17/2018] [Indexed: 12/25/2022]
Abstract
Autism spectrum disorders (ASD) are a group of early-onset neurodevelopmental conditions characterized by alterations in brain connectivity with cascading effects on neuropsychological functions. To date, in the framework of an increasing interest about environmental conditions which could interact with genetic factors in ASD pathogenesis, many authors have stressed that changes in the intrauterine environment at different stages of pregnancy, such as those linked to maternal metabolic pathologies, may lead to long-term conditions in the newborn. In particular, a growing number of epidemiological studies have highlighted the role of obesity and maternal diabetes as a risk factor for developing both somatic and psychiatric disorders in humans, including ASD. While literature still fails in identifying specific etiopathological mechanisms, a growing body of evidence is available about the presence of a relationship between maternal immune dysregulation, inflammation, oxidative stress, and the development of ASD in the offspring. In this framework, results from high-fat diet animal models about the role played by oxidative stress in shaping offspring neurodevelopment may help in clarifying the pathways through which maternal metabolic conditions are linked with ASD. The aim of this review is to provide an overview of literature about the effects of early life insults linked to oxidative stress which may be involved in ASD etiopathogenesis and how this relationship can be explained in biological terms.
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24
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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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25
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Abstract
The mechanistic target of rapamycin (mTOR) is an important signaling hub that integrates environmental information regarding energy availability and stimulates anabolic molecular processes and cell growth. Abnormalities in this pathway have been identified in several syndromes in which autism spectrum disorder (ASD) is highly prevalent. Several studies have investigated mTOR signaling in developmental and neuronal processes that, when dysregulated, could contribute to the development of ASD. Although many potential mechanisms still remain to be fully understood, these associations are of great interest because of the clinical availability of mTOR inhibitors. Clinical trials evaluating the efficacy of mTOR inhibitors to improve neurodevelopmental outcomes have been initiated.
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Affiliation(s)
- Kellen D. Winden
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Darius Ebrahimi-Fakhari
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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26
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Baltussen LL, Rosianu F, Ultanir SK. Kinases in synaptic development and neurological diseases. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:343-352. [PMID: 29241837 DOI: 10.1016/j.pnpbp.2017.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/08/2017] [Accepted: 12/09/2017] [Indexed: 10/18/2022]
Abstract
Neuronal morphogenesis and synapse development is essential for building a functioning nervous system, and defects in these processes are associated with neurological disorders. Our understanding of molecular components and signalling events that contribute to neuronal development and pathogenesis is limited. Genes associated with neurodevelopmental and neurodegenerative diseases provide entry points for elucidating molecular events that contribute to these conditions. Several protein kinases, enzymes that regulate protein function by phosphorylating their substrates, are genetically linked to neurological disorders. Identifying substrates of these kinases is key to discovering their function and providing insight for possible therapies. In this review, we describe how various methods for kinase-substrate identification helped elucidate kinase signalling pathways important for neuronal development and function. We describe recent advances on roles of kinases TAOK2, TNIK and CDKL5 in neuronal development and the converging pathways of LRRK2, PINK1 and GAK in Parkinson's Disease.
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Affiliation(s)
- Lucas L Baltussen
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Flavia Rosianu
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Sila K Ultanir
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom.
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27
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Manoli DS, Tollkuhn J. Gene regulatory mechanisms underlying sex differences in brain development and psychiatric disease. Ann N Y Acad Sci 2018; 1420:26-45. [PMID: 29363776 PMCID: PMC5991992 DOI: 10.1111/nyas.13564] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/26/2017] [Accepted: 11/01/2017] [Indexed: 12/12/2022]
Abstract
The sexual differentiation of the mammalian nervous system requires the precise coordination of the temporal and spatial regulation of gene expression in diverse cell types. Sex hormones act at multiple developmental time points to specify sex-typical differentiation during embryonic and early development and to coordinate subsequent responses to gonadal hormones later in life by establishing sex-typical patterns of epigenetic modifications across the genome. Thus, mutations associated with neuropsychiatric conditions may result in sexually dimorphic symptoms by acting on different neural substrates or chromatin landscapes in males and females. Finally, as stress hormone signaling may directly alter the molecular machinery that interacts with sex hormone receptors to regulate gene expression, the contribution of chronic stress to the pathogenesis or presentation of mental illness may be additionally different between the sexes. Here, we review the mechanisms that contribute to sexual differentiation in the mammalian nervous system and consider some of the implications of these processes for sex differences in neuropsychiatric conditions.
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Affiliation(s)
- Devanand S. Manoli
- Department of Psychiatry and Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, California
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Gulmez Karaca K, Brito DVC, Zeuch B, Oliveira AMM. Adult hippocampal MeCP2 preserves the genomic responsiveness to learning required for long-term memory formation. Neurobiol Learn Mem 2018; 149:84-97. [PMID: 29438740 DOI: 10.1016/j.nlm.2018.02.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/04/2018] [Accepted: 02/09/2018] [Indexed: 01/09/2023]
Abstract
MeCP2 is required both during postnatal neurodevelopment and throughout the adult life for brain function. Although it is well accepted that MeCP2 in the maturing nervous system is critical for establishing normal development, the functions of MeCP2 during adulthood are poorly understood. Particularly, the requirement of hippocampal MeCP2 for cognitive abilities in the adult is not studied. To characterize the role of MeCP2 in adult neuronal function and cognition, we used a temporal and region-specific disruption of MeCP2 expression in the hippocampus of adult male mice. We found that MeCP2 is required for long-term memory formation and that it controls the learning-induced transcriptional response of hippocampal neurons required for memory consolidation. Furthermore, we uncovered MeCP2 functions in the adult hippocampus that may underlie cognitive integrity. We showed that MeCP2 maintains the developmentally established chromatin configuration and epigenetic landscape of CA1 neurons throughout the adulthood, and that it regulates the expression of neuronal and immune-related genes in the adult hippocampus. Overall, our findings identify MeCP2 as a maintenance factor in the adult hippocampus that preserves signal responsiveness of the genome and allows for integrity of cognitive functions. This study provides new insight into how MeCP2 maintains adult brain functions, but also into the mechanisms underlying the cognitive impairments observed in RTT patients and highlights the understudied role of DNA methylation interpretation in adult cognitive processes.
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Affiliation(s)
- Kubra Gulmez Karaca
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - David V C Brito
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Benjamin Zeuch
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Ana M M Oliveira
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany.
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Cobolli Gigli C, Scaramuzza L, De Simone M, Rossi RL, Pozzi D, Pagani M, Landsberger N, Bedogni F. Lack of Methyl-CpG Binding Protein 2 (MeCP2) Affects Cell Fate Refinement During Embryonic Cortical Development. Cereb Cortex 2018; 28:1846-1856. [DOI: 10.1093/cercor/bhx360] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Indexed: 12/14/2022] Open
Affiliation(s)
- Clementina Cobolli Gigli
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Hospital, 20132 Milan, Italy
| | - Linda Scaramuzza
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Hospital, 20132 Milan, Italy
| | - Marco De Simone
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”, 20122 Milan, Italy
| | - Riccardo L Rossi
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”, 20122 Milan, Italy
| | - Davide Pozzi
- Laboratory of Pharmacology and Brain Pathology, IRCCS Humanitas, 20089 Rozzano (MI) and Hunimed University, 20090 Pieve Emanuele (MI), Italy
| | - Massimiliano Pagani
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”, 20122 Milan, Italy
| | - Nicoletta Landsberger
- Department of Medical Biotechnology and Translational Medicine, University of Milan, 20090 Segrate, Milan, Italy
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Hospital, 20132 Milan, Italy
| | - Francesco Bedogni
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Hospital, 20132 Milan, Italy
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Abstract
PURPOSE OF REVIEW Studies investigating postnatal brain growth disorders inform the biology underlying the development of human brain circuitry. This research is becoming increasingly important for the diagnosis and treatment of childhood neurodevelopmental disorders, including autism and related disorders. Here, we review recent research on typical and abnormal postnatal brain growth and examine potential biological mechanisms. RECENT FINDINGS Clinically, brain growth disorders are heralded by diverging head size for a given age and sex, but are more precisely characterized by brain imaging, post-mortem analysis, and animal model studies. Recent neuroimaging and molecular biological studies on postnatal brain growth disorders have broadened our view of both typical and pathological postnatal neurodevelopment. Correlating gene and protein function with brain growth trajectories uncovers postnatal biological mechanisms, including neuronal arborization, synaptogenesis and pruning, and gliogenesis and myelination. Recent investigations of childhood neurodevelopmental and neurodegenerative disorders highlight the underlying genetic programming and experience-dependent remodeling of neural circuitry. SUMMARY To understand typical and abnormal postnatal brain development, clinicians and researchers should characterize brain growth trajectories in the context of neurogenetic syndromes. Understanding mechanisms and trajectories of postnatal brain growth will aid in differentiating, diagnosing, and potentially treating neurodevelopmental disorders.
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Neuron-specific alternative splicing of transcriptional machineries: Implications for neurodevelopmental disorders. Mol Cell Neurosci 2017; 87:35-45. [PMID: 29254826 DOI: 10.1016/j.mcn.2017.10.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 10/18/2017] [Accepted: 10/24/2017] [Indexed: 02/07/2023] Open
Abstract
The brain has long been known to display the most complex pattern of alternative splicing, thereby producing diverse protein isoforms compared to other tissues. Recent evidence indicates that many alternative exons are neuron-specific, evolutionarily conserved, and found in regulators of transcription including DNA-binding protein and histone modifying enzymes. This raises a possibility that neurons adopt unique mechanisms of transcription. Given that transcriptional machineries are frequently mutated in neurodevelopmental disorders with cognitive dysfunction, it is important to understand how neuron-specific alternative splicing contributes to proper transcriptional regulation in the brain. In this review, we summarize current knowledge regarding how neuron-specific splicing events alter the function of transcriptional regulators and shape unique gene expression patterns in the brain and the implications of neuronal splicing to the pathophysiology of neurodevelopmental disorders.
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Clukay CJ, Hughes DA, Rodney NC, Kertes DA, Mulligan CJ. DNA methylation of methylation complex genes in relation to stress and genome-wide methylation in mother-newborn dyads. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2017; 165:173-182. [PMID: 29028111 DOI: 10.1002/ajpa.23341] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 08/11/2017] [Accepted: 10/01/2017] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Early life stress is known to have enduring biological effects, particularly with respect to health. Epigenetic modifications, such as DNA methylation, are a possible mechanism to mediate the biological effect of stress. We previously found correlations between maternal stress, newborn birthweight, and genome-wide measures of DNA methylation. Here we investigate ten genes related to the methylation/demethylation complex in order to better understand the impact of stress on health. MATERIALS AND METHODS DNA methylation and genetic variants at methylation/demethylation genes were assayed. Mean methylation measures were constructed for each gene and tested, in addition to genetic variants, for association with maternal stress measures based on interview and survey data (chronic stress and war trauma), maternal venous, and newborn cord genome-wide mean methylation (GMM), and birthweight. RESULTS After cell type correction, we found multiple pairwise associations between war trauma, maternal GMM, maternal methylation at DNMT1, DNMT3A, TET3, and MBD2, and birthweight. CONCLUSIONS The association of maternal GMM and maternal methylation at DNMT1, DNMT3A, TET3, and MBD2 is consistent with the role of these genes in establishing, maintaining and altering genome-wide methylation patterns, in some cases in response to stress. DNMT1 produces one of the primary enzymes that reproduces methylation patterns during DNA replication. DNMT3A and TET3 have been implicated in genome-wide hypomethylation in response to glucocorticoid hormones. Although we cannot determine the directionality of the genic and genome-wide changes in methylation, our results suggest that altered methylation of specific methylation genes may be part of the molecular mechanism underlying the human biological response to stress.
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Chen CY, Di Lucente J, Lin YC, Lien CC, Rogawski MA, Maezawa I, Jin LW. Defective GABAergic neurotransmission in the nucleus tractus solitarius in Mecp2-null mice, a model of Rett syndrome. Neurobiol Dis 2017; 109:25-32. [PMID: 28927958 DOI: 10.1016/j.nbd.2017.09.006] [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] [Received: 05/04/2017] [Revised: 08/14/2017] [Accepted: 09/14/2017] [Indexed: 01/12/2023] Open
Abstract
Rett syndrome (RTT) is a devastating neurodevelopmental disorder caused by loss-of-function mutations in the X-linked methyl-CpG binding protein 2 (Mecp2) gene. GABAergic dysfunction has been implicated contributing to the respiratory dysfunction, one major clinical feature of RTT. The nucleus tractus solitarius (NTS) is the first central site integrating respiratory sensory information that can change the nature of the reflex output. We hypothesized that deficiency in Mecp2 gene reduces GABAergic neurotransmission in the NTS. Using whole-cell patch-clamp recordings in NTS slices, we measured spontaneous inhibitory postsynaptic currents (sIPSCs), miniature IPSCs (mIPSCs), NTS-evoked IPSCs (eIPSCs), and GABAA receptor (GABAA-R) agonist-induced responses. Compared to those from wild-type mice, NTS neurons from Mecp2-null mice had significantly (p<0.05) reduced sIPSC amplitude, sIPSC frequency, and mIPSC amplitude but not mIPSC frequency. Mecp2-null mice also had decreased eIPSC amplitude with no change in paired-pulse ratio. The data suggest reduced synaptic receptor-mediated phasic GABA transmission in Mecp2-null mice. In contrast, muscimol (GABAA-R agonist, 0.3-100μM) and THIP (selective extrasynaptic GABAA-R agonist, 5μM) induced significantly greater current response in Mecp2-null mice, suggesting increased extrasynaptic receptors. Using qPCR, we found a 2.5 fold increase in the delta subunit of the GABAA-Rs in the NTS in Mecp2-null mice, consistent with increased extrasynaptic receptors. As the NTS was recently found required for respiratory pathology in RTT, our results provide a mechanism for NTS dysfunction which involves shifting the balance of synaptic/extrasynaptic receptors in favor of extrasynaptic site, providing a target for boosting GABAergic inhibition in RTT.
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Affiliation(s)
- Chao-Yin Chen
- Department of Pharmacology, University of California Davis, One Shields Avenue, Davis, CA 95616, United States.
| | - Jacopo Di Lucente
- Department of Pathology and Laboratory Medicine, University of California Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Yen-Chu Lin
- Department of Pathology and Laboratory Medicine, University of California Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Cheng-Chang Lien
- Institute of Neuroscience, National Yang-Ming University, Taipei 112, Taiwan
| | - Michael A Rogawski
- Department of Neurology, University of California Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Izumi Maezawa
- Department of Pathology and Laboratory Medicine, University of California Davis, One Shields Avenue, Davis, CA 95616, United States; M.I.N.D. (Medical Investigation of Neurodevelopmental Disorders) Institute, University of California Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine, University of California Davis, One Shields Avenue, Davis, CA 95616, United States; M.I.N.D. (Medical Investigation of Neurodevelopmental Disorders) Institute, University of California Davis, One Shields Avenue, Davis, CA 95616, United States.
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Schroeder JC, Reim D, Boeckers TM, Schmeisser MJ. Genetic Animal Models for Autism Spectrum Disorder. Curr Top Behav Neurosci 2017; 30:311-324. [PMID: 26602248 DOI: 10.1007/7854_2015_407] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Autism spectrum disorder (ASD) affects approximately 1 % of the human population and has a strong genetic component. Hence, the recent discovery of major "ASD genes" has subsequently resulted in the generation of several genetic animal models of ASD. Careful analysis of behavioral phenotypes and characterization of the underlying neurobiological mechanisms in these models should further help us to identify novel therapeutic targets and develop more effective strategies in the future to ameliorate or even reverse core symptoms and comorbidities of ASD. In this review, we will focus on the mutant mouse as animal model and outline how to characterize both behavioral and neurobiological phenotypes in this organism. We will further discuss a selection of major ASD mutant mouse lines. Our conclusions will finally address the current goals and perspectives in the field to obtain a more comprehensive and possibly also converging picture of ASD pathogenesis, which could be most useful for the desired bench-to-bedside strategy of translational medicine for this complex disorder.
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Affiliation(s)
- Jan C Schroeder
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Dominik Reim
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Tobias M Boeckers
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Michael J Schmeisser
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany.
- Department of Neurology, Ulm University, Ulm, Germany.
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Golgi trafficking defects in postnatal microcephaly: The evidence for “Golgipathies”. Prog Neurobiol 2017; 153:46-63. [DOI: 10.1016/j.pneurobio.2017.03.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/22/2017] [Accepted: 03/29/2017] [Indexed: 12/17/2022]
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A Tox21 Approach to Altered Epigenetic Landscapes: Assessing Epigenetic Toxicity Pathways Leading to Altered Gene Expression and Oncogenic Transformation In Vitro. Int J Mol Sci 2017; 18:ijms18061179. [PMID: 28587163 PMCID: PMC5486002 DOI: 10.3390/ijms18061179] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 05/19/2017] [Accepted: 05/22/2017] [Indexed: 02/07/2023] Open
Abstract
An emerging vision for toxicity testing in the 21st century foresees in vitro assays assuming the leading role in testing for chemical hazards, including testing for carcinogenicity. Toxicity will be determined by monitoring key steps in functionally validated molecular pathways, using tests designed to reveal chemically-induced perturbations that lead to adverse phenotypic endpoints in cultured human cells. Risk assessments would subsequently be derived from the causal in vitro endpoints and concentration vs. effect data extrapolated to human in vivo concentrations. Much direct experimental evidence now shows that disruption of epigenetic processes by chemicals is a carcinogenic mode of action that leads to altered gene functions playing causal roles in cancer initiation and progression. In assessing chemical safety, it would therefore be advantageous to consider an emerging class of carcinogens, the epigenotoxicants, with the ability to change chromatin and/or DNA marks by direct or indirect effects on the activities of enzymes (writers, erasers/editors, remodelers and readers) that convey the epigenetic information. Evidence is reviewed supporting a strategy for in vitro hazard identification of carcinogens that induce toxicity through disturbance of functional epigenetic pathways in human somatic cells, leading to inactivated tumour suppressor genes and carcinogenesis. In the context of human cell transformation models, these in vitro pathway measurements ensure high biological relevance to the apical endpoint of cancer. Four causal mechanisms participating in pathways to persistent epigenetic gene silencing were considered: covalent histone modification, nucleosome remodeling, non-coding RNA interaction and DNA methylation. Within these four interacting mechanisms, 25 epigenetic toxicity pathway components (SET1, MLL1, KDM5, G9A, SUV39H1, SETDB1, EZH2, JMJD3, CBX7, CBX8, BMI, SUZ12, HP1, MPP8, DNMT1, DNMT3A, DNMT3B, TET1, MeCP2, SETDB2, BAZ2A, UHRF1, CTCF, HOTAIR and ANRIL) were found to have experimental evidence showing that functional perturbations played “driver” roles in human cellular transformation. Measurement of epigenotoxicants presents challenges for short-term carcinogenicity testing, especially in the high-throughput modes emphasized in the Tox21 chemicals testing approach. There is need to develop and validate in vitro tests to detect both, locus-specific, and genome-wide, epigenetic alterations with causal links to oncogenic cellular phenotypes. Some recent examples of cell-based high throughput chemical screening assays are presented that have been applied or have shown potential for application to epigenetic endpoints.
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Zhao D, Mokhtari R, Pedrosa E, Birnbaum R, Zheng D, Lachman HM. Transcriptome analysis of microglia in a mouse model of Rett syndrome: differential expression of genes associated with microglia/macrophage activation and cellular stress. Mol Autism 2017; 8:17. [PMID: 28367307 PMCID: PMC5372344 DOI: 10.1186/s13229-017-0134-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/17/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a severe, neurodevelopmental disorder primarily affecting girls, characterized by progressive loss of cognitive, social, and motor skills after a relatively brief period of typical development. It is usually due to de novo loss of function mutations in the X-linked gene, MeCP2, which codes for the gene expression and chromatin regulator, methyl-CpG binding protein 2. Although the behavioral phenotype appears to be primarily due to neuronal Mecp2 deficiency in mice, other cell types, including astrocytes and oligodendrocytes, also appear to contribute to some aspects of the RTT phenotype. In addition, microglia may also play a role. However, the effect of Mecp2 deficiency in microglia on RTT pathogenesis is controversial. METHODS In the current study, we applied whole transcriptome analysis using RNA-seq to gain insight into molecular pathways in microglia that might be dysregulated during the transition, in female mice heterozygous for an Mecp2-null allele (Mecp2+/-; Het), from the pre-phenotypic (5 weeks) to the phenotypic phases (24 weeks). RESULTS We found a significant overlap in differentially expressed genes (DEGs) with genes involved in regulating the extracellular matrix, and those that are activated or inhibited when macrophages and microglia are stimulated towards the M1 and M2 activation states. However, the M1- and M2-associated genes were different in the 5- and 24-week samples. In addition, a substantial decrease in the expression of nine members of the heat shock protein (HSP) family was found in the 5-week samples, but not at 24 weeks. CONCLUSIONS These findings suggest that microglia from pre-phenotypic and phenotypic female mice are activated in a manner different from controls and that pre-phenotypic female mice may have alterations in their capacity to response to heat stress and other stressors that function through the HSP pathway.
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Affiliation(s)
- Dejian Zhao
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Ryan Mokhtari
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Rayna Birnbaum
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Neurology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
| | - Herbert M Lachman
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA.,Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY USA
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MeCP2, A Modulator of Neuronal Chromatin Organization Involved in Rett Syndrome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 978:3-21. [PMID: 28523538 DOI: 10.1007/978-3-319-53889-1_1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
From an epigenetic perspective, the genomic chromatin organization of neurons exhibits unique features when compared to somatic cells. Methyl CpG binding protein 2 (MeCP2), through its ability to bind to methylated DNA, seems to be a major player in regulating such unusual organization. An important contribution to this uniqueness stems from the intrinsically disordered nature of this highly abundant chromosomal protein in neurons. Upon its binding to methylated/hydroxymethylated DNA, MeCP2 is able to recruit a plethora of interacting protein and RNA partners. The final outcome is a highly specialized chromatin organization wherein linker histones (histones of the H1 family) and MeCP2 share an organizational role that dynamically changes during neuronal development and that it is still poorly understood. MeCP2 mutations alter its chromatin-binding dynamics and/or impair the ability of the protein to interact with some of its partners, resulting in Rett syndrome (RTT). Therefore, deciphering the molecular details involved in the MeCP2 neuronal chromatin arrangement is critical for our understanding of the proper and altered functionality of these cells.
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Claveria-Gimeno R, Abian O, Velazquez-Campoy A, Ausió J. MeCP2… Nature’s Wonder Protein or Medicine’s Most Feared One? CURRENT GENETIC MEDICINE REPORTS 2016. [DOI: 10.1007/s40142-016-0107-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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40
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Oliveira AMM. DNA methylation: a permissive mark in memory formation and maintenance. ACTA ACUST UNITED AC 2016; 23:587-93. [PMID: 27634149 PMCID: PMC5026210 DOI: 10.1101/lm.042739.116] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/14/2016] [Indexed: 01/06/2023]
Abstract
DNA methylation was traditionally viewed as a static mechanism required during cell fate determination. This view has been challenged and it is now accepted that DNA methylation is involved in the regulation of genomic responses in mature neurons, particularly in cognitive functions. The evidence for a role of DNA methylation in memory formation and maintenance comes from the increasing number of studies that have assessed the effects of manipulation of DNA methylation modifiers in the ability to form and maintain memories. Moreover, insights from genome-wide analyses of the hippocampal DNA methylation status after neuronal activity show that DNA methylation is dynamically regulated. Despite all the experimental evidence, we are still far from having a clear picture of how DNA methylation regulates long-term adaptations. This review aims on one hand to describe the findings that led to the confirmation of DNA methylation as an important player in memory formation. On the other hand, it tries to integrate these discoveries into the current views of how memories are formed and maintained.
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Affiliation(s)
- Ana M M Oliveira
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, 69120 Heidelberg, Germany
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41
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Arsenault J, Gholizadeh S, Niibori Y, Pacey LK, Halder SK, Koxhioni E, Konno A, Hirai H, Hampson DR. FMRP Expression Levels in Mouse Central Nervous System Neurons Determine Behavioral Phenotype. Hum Gene Ther 2016; 27:982-996. [PMID: 27604541 PMCID: PMC5178026 DOI: 10.1089/hum.2016.090] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fragile X mental retardation protein (FMRP) is absent or highly reduced in Fragile X Syndrome, a genetic disorder causing cognitive impairment and autistic behaviors. Previous proof-of-principle studies have demonstrated that restoring FMRP in the brain using viral vectors can improve pathological abnormalities in mouse models of fragile X. However, unlike small molecule drugs where the dose can readily be adjusted during treatment, viral vector–based biological therapeutic drugs present challenges in terms of achieving optimal dosing and expression levels. The objective of this study was to investigate the consequences of expressing varying levels of FMRP selectively in neurons of Fmr1 knockout and wild-type (WT) mice. A wide range of neuronal FMRP transgene levels was achieved in individual mice after intra-cerebroventricular administration of adeno-associated viral vectors coding for FMRP. In all treated knockout mice, prominent FMRP transgene expression was observed in forebrain structures, whereas lower levels were present in more caudal regions of the brain. Reduced levels of the synaptic protein PSD-95, elevated levels of the transcriptional modulator MeCP2, and abnormal motor activity, anxiety, and acoustic startle responses in Fmr1 knockout mice were fully or partially rescued after expression of FMRP at about 35–115% of WT expression, depending on the brain region examined. In the WT mouse, moderate FMRP over-expression of up to about twofold had little or no effect on PSD-95 and MeCP2 levels or on behavioral endophenotypes. In contrast, excessive over-expression in the Fmr1 knockout mouse forebrain (approximately 2.5–6-fold over WT) induced pathological motor hyperactivity and suppressed the startle response relative to WT mice. These results delineate a range of FMRP expression levels in the central nervous system that confer phenotypic improvement in fragile X mice. Collectively, these findings are pertinent to the development of long-term curative gene therapy strategies for treating Fragile X Syndrome and other neurodevelopmental disorders.
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Affiliation(s)
- Jason Arsenault
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Shervin Gholizadeh
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Yosuke Niibori
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Laura K Pacey
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Sebok K Halder
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Enea Koxhioni
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Ayumu Konno
- 2 Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hirokazu Hirai
- 2 Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - David R Hampson
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.,3 Department of Pharmacology, Faculty of Medicine, University of Toronto , Toronto, Ontario, Canada
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Nott A, Cheng J, Gao F, Lin YT, Gjoneska E, Ko T, Minhas P, Zamudio AV, Meng J, Zhang F, Jin P, Tsai LH. Histone deacetylase 3 associates with MeCP2 to regulate FOXO and social behavior. Nat Neurosci 2016; 19:1497-1505. [PMID: 27428650 PMCID: PMC5083138 DOI: 10.1038/nn.4347] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/23/2016] [Indexed: 12/12/2022]
Abstract
Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome (RTT). The RTT missense MECP2R306C mutation prevents MeCP2 interaction with NCoR/Histone deacetylase 3 (HDAC3); however, the neuronal function of HDAC3 is incompletely understood. We report that neuronal deletion of Hdac3 in mice elicits abnormal locomotor coordination, sociability, and cognition. Transcriptional and chromatin profiling revealed HDAC3 positively regulates a subset of genes and is recruited to active gene promoters via MeCP2. HDAC3-associated promoters are enriched for the FOXO transcription factors, and FOXO acetylation is elevated in Hdac3 KO and Mecp2 KO neurons. Human RTT patient-derived MECP2R306C neural progenitor cells have deficits in HDAC3 and FOXO recruitment and gene expression. Gene editing of MECP2R306C cells to generate isogenic controls rescued HDAC3-FOXO-mediated impairments in gene expression. Our data suggests that HDAC3 interaction with MeCP2 positively regulates a subset of neuronal genes through FOXO deacetylation, and disruption of HDAC3 contributes to cognitive and social impairment.
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Affiliation(s)
- Alexi Nott
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jemmie Cheng
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Fan Gao
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Yuan-Ta Lin
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Elizabeta Gjoneska
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Broad Institute of Harvard University and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Tak Ko
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Paras Minhas
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Present addresses: Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA (P.M.), and Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, China (J.M.)
| | - Alicia Viridiana Zamudio
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jia Meng
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Present addresses: Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA (P.M.), and Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, China (J.M.)
| | - Feiran Zhang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Li-Huei Tsai
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Broad Institute of Harvard University and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Desai A, Sequeira JM, Quadros EV. The metabolic basis for developmental disorders due to defective folate transport. Biochimie 2016; 126:31-42. [DOI: 10.1016/j.biochi.2016.02.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/22/2016] [Indexed: 02/06/2023]
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Yao B, Christian KM, He C, Jin P, Ming GL, Song H. Epigenetic mechanisms in neurogenesis. Nat Rev Neurosci 2016; 17:537-49. [PMID: 27334043 DOI: 10.1038/nrn.2016.70] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the embryonic and adult brain, neural stem cells proliferate and give rise to neurons and glia through highly regulated processes. Epigenetic mechanisms - including DNA and histone modifications, as well as regulation by non-coding RNAs - have pivotal roles in different stages of neurogenesis. Aberrant epigenetic regulation also contributes to the pathogenesis of various brain disorders. Here, we review recent advances in our understanding of epigenetic regulation in neurogenesis and its dysregulation in brain disorders, including discussion of newly identified DNA cytosine modifications. We also briefly cover the emerging field of epitranscriptomics, which involves modifications of mRNAs and long non-coding RNAs.
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Affiliation(s)
- Bing Yao
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - Kimberly M Christian
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
| | - Chuan He
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - Guo-Li Ming
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
| | - Hongjun Song
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
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Abstract
Adult diffuse gliomas account for the majority of primary malignant brain tumours, and are in most cases lethal. Current therapies are often only marginally effective, and improved options will almost certainly benefit from further insight into the various processes contributing to gliomagenesis and pathology. While molecular characterization of these tumours classifies them on the basis of genetic alterations and chromosomal abnormalities, DNA methylation patterns are increasingly understood to play a role in glioma pathogenesis. Indeed, a subset of gliomas associated with improved survival is characterized by the glioma CpG island methylator phenotype (G-CIMP), which can be induced by the expression of mutant isocitrate dehydrogenase (IDH1/2). Aberrant methylation of particular genes or regulatory elements, within the context of G-CIMP-positive and/or negative tumours, has also been shown to be associated with differential survival. In this review, we provide an overview of the current knowledge regarding the role of DNA methylation in adult diffuse gliomas. In particular, we discuss IDH mutations and G-CIMP, MGMT promoter methylation, DNA methylation-mediated microRNA regulation and aberrant methylation of specific genes or groups of genes.
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Pandey S, Simmons GE, Malyarchuk S, Calhoun TN, Pruitt K. A novel MeCP2 acetylation site regulates interaction with ATRX and HDAC1. Genes Cancer 2015; 6:408-21. [PMID: 26622943 PMCID: PMC4633168 DOI: 10.18632/genesandcancer.84] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Methyl-CpG-binding protein-2 (MeCP2) regulates gene expression by recruiting SWI/SNF DNA helicase/ATPase (ATRX) and Histone Deacetylase-1 (HDAC1) to methylated gene regions and modulates heterochromatin association by interacting with Heterochromatin protein-1. As MeCP2 contributes to tumor suppressor gene silencing and its mutation causes Rett Syndrome, we investigated how novel post-translational-modification contributes to its function. Herein we report that upon pharmacological inhibition of SIRT1 in RKO colon and MCF-7 breast cancer cells, endogenous MeCP2 is acetylated at sites critical for binding to DNA and transcriptional regulators. We created an acetylation mimetic mutation in MeCP2 and found it to possess decreased binding to ATRX and HDAC1. Conditions inducing MeCP2 acetylation do not alter its promoter occupancy at a subset of target genes analyzed, but do cause decreased binding to ATRX and HDAC1. We also report here that a specific inhibitor of SIRT1, IV, can be used to selectively decrease H3K27me3 repressive marks on a subset of repressed target gene promoters analyzed. Lastly, we show that RKO cells over-expressing MeCP2 mutant show reduced proliferation compared to those over-expressing MeCP2-wildtype. Our study demonstrates the importance of acetylated lysine residues and suggests their key role in regulating MeCP2 function and its ability to bind transcriptional regulators.
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Affiliation(s)
- Somnath Pandey
- Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Glenn E Simmons
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Svitlana Malyarchuk
- Molecular and Cellular Physiology, Shreveport, LA, USA ; LSU Health Sciences Center School of Medicine, Shreveport, LA, USA
| | - Tara N Calhoun
- Molecular and Cellular Physiology, Shreveport, LA, USA ; LSU Health Sciences Center School of Medicine, Shreveport, LA, USA
| | - Kevin Pruitt
- Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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LeBlanc JJ, DeGregorio G, Centofante E, Vogel-Farley VK, Barnes K, Kaufmann WE, Fagiolini M, Nelson CA. Visual evoked potentials detect cortical processing deficits in Rett syndrome. Ann Neurol 2015; 78:775-86. [PMID: 26332183 DOI: 10.1002/ana.24513] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 08/07/2015] [Accepted: 08/26/2015] [Indexed: 01/26/2023]
Abstract
OBJECTIVE Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutation of the X-linked MECP2 gene and characterized by developmental regression during the first few years of life. The objective of this study was to investigate if the visual evoked potential (VEP) could be used as an unbiased, quantitative biomarker to monitor brain function in RTT. METHODS We recorded pattern-reversal VEPs in Mecp2 heterozygous female mice and 34 girls with RTT. The amplitudes and latencies of VEP waveform components were quantified, and were related to disease stage, clinical severity, and MECP2 mutation type in patients. Visual acuity was also assessed in both mice and patients by modulating the spatial frequency of the stimuli. RESULTS Mecp2 heterozygous female mice and RTT patients exhibited a similar decrease in VEP amplitude that was most striking in the later stages of the disorder. RTT patients also displayed a slower recovery from the principal peak of the VEP response that was impacted by MECP2 mutation type. When the spatial frequency of the stimulus was increased, both patients and mice displayed a deficit in discriminating smaller patterns, indicating lower visual spatial acuity in RTT. INTERPRETATION VEP is a method that can be used to assess brain function across species and in children with severe disabilities like RTT. Our findings support the introduction of standardized VEP analysis in clinical and research settings to probe the neurobiological mechanism underlying functional impairment and to longitudinally monitor progression of the disorder and response to treatment.
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Affiliation(s)
- Jocelyn J LeBlanc
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Boston.,F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Boston.,Harvard Medical School, Boston
| | - Geneva DeGregorio
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Boston
| | - Eleonora Centofante
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Boston
| | - Vanessa K Vogel-Farley
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Boston
| | - Katherine Barnes
- Rett Syndrome Program, Department of Neurology, Boston Children's Hospital, Boston
| | - Walter E Kaufmann
- Harvard Medical School, Boston.,Rett Syndrome Program, Department of Neurology, Boston Children's Hospital, Boston
| | - Michela Fagiolini
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Boston.,Harvard Medical School, Boston
| | - Charles A Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Boston.,Harvard Medical School, Boston.,Harvard Graduate School of Education, Cambridge, MA
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Shrestha P, Mousa A, Heintz N. Layer 2/3 pyramidal cells in the medial prefrontal cortex moderate stress induced depressive behaviors. eLife 2015; 4. [PMID: 26371510 PMCID: PMC4566133 DOI: 10.7554/elife.08752] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 08/08/2015] [Indexed: 12/27/2022] Open
Abstract
Major depressive disorder (MDD) is a prevalent illness that can be precipitated by acute or chronic stress. Studies of patients with Wolfram syndrome and carriers have identified Wfs1 mutations as causative for MDD. The medial prefrontal cortex (mPFC) is known to be involved in depression and behavioral resilience, although the cell types and circuits in the mPFC that moderate depressive behaviors in response to stress have not been determined. Here, we report that deletion of Wfs1 from layer 2/3 pyramidal cells impairs the ability of the mPFC to suppress stress-induced depressive behaviors, and results in hyperactivation of the hypothalamic–pituitary–adrenal axis and altered accumulation of important growth and neurotrophic factors. Our data identify superficial layer 2/3 pyramidal cells as critical for moderation of stress in the context of depressive behaviors and suggest that dysfunction in these cells may contribute to the clinical relationship between stress and depression. DOI:http://dx.doi.org/10.7554/eLife.08752.001 Around 16% of people will experience an episode of major depression at some point in their lives, with symptoms including a loss of motivation, a reduced enjoyment of previously pleasurable activities, and disturbances in sleep and appetite. Multiple genes and environmental factors have been implicated in depression, and one of the strongest risk factors for developing the disorder is exposure to stress. Stress and depression affect many of the same brain regions, most notably the prefrontal cortex—an area that is involved in decision making, problem solving and regulating emotions. Shrestha et al. therefore reasoned that a good way of obtaining insights into the relationship between stress and depression would be to study prefrontal cortex cells that express genes that have been linked to depression. One such gene is Wfs1. Mutations in this gene cause a rare disorder called Wolfram syndrome, in which affected individuals experience a wide range of symptoms that often include severe depression. Shrestha et al. identified a specific population of cells in the prefrontal cortex that express Wfs1. When subjected to a stressful event, such as being restrained, mice that had been genetically modified to lack this gene in their prefrontal cortex were more likely to exhibit depression-like behaviors than non-modified mice. The genetically modified mice also released more stress hormones when restrained and produced different amounts of a number of proteins that regulate the growth and signaling of neurons. Shrestha et al. propose that these proteins act on neural circuits that control how the mice respond to stress. Furthermore, changes in the levels or the distribution of these proteins may increase the likelihood that a stressful event will trigger behaviors associated with depression. Further experiments are required to investigate the possibility that using drugs to manipulate cells that express Wfs1 could protect against the harmful effects of stress, or even treat existing episodes of depression. DOI:http://dx.doi.org/10.7554/eLife.08752.002
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Affiliation(s)
- Prerana Shrestha
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Awni Mousa
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
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