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MeCP2 Is an Epigenetic Factor That Links DNA Methylation with Brain Metabolism. Int J Mol Sci 2023; 24:ijms24044218. [PMID: 36835623 PMCID: PMC9966807 DOI: 10.3390/ijms24044218] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
DNA methylation, one of the most well-studied epigenetic modifications, is involved in a wide spectrum of biological processes. Epigenetic mechanisms control cellular morphology and function. Such regulatory mechanisms involve histone modifications, chromatin remodeling, DNA methylation, non-coding regulatory RNA molecules, and RNA modifications. One of the most well-studied epigenetic modifications is DNA methylation that plays key roles in development, health, and disease. Our brain is probably the most complex part of our body, with a high level of DNA methylation. A key protein that binds to different types of methylated DNA in the brain is the methyl-CpG binding protein 2 (MeCP2). MeCP2 acts in a dose-dependent manner and its abnormally high or low expression level, deregulation, and/or genetic mutations lead to neurodevelopmental disorders and aberrant brain function. Recently, some of MeCP2-associated neurodevelopmental disorders have emerged as neurometabolic disorders, suggesting a role for MeCP2 in brain metabolism. Of note, MECP2 loss-of-function mutation in Rett Syndrome is reported to cause impairment of glucose and cholesterol metabolism in human patients and/or mouse models of disease. The purpose of this review is to outline the metabolic abnormalities in MeCP2-associated neurodevelopmental disorders that currently have no available cure. We aim to provide an updated overview into the role of metabolic defects associated with MeCP2-mediated cellular function for consideration of future therapeutic strategies.
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Lattke M, Guillemot F. Understanding astrocyte differentiation: Clinical relevance, technical challenges, and new opportunities in the omics era. WIREs Mech Dis 2022; 14:e1557. [PMID: 35546493 PMCID: PMC9539907 DOI: 10.1002/wsbm.1557] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 03/23/2022] [Accepted: 03/25/2022] [Indexed: 11/06/2022]
Abstract
Astrocytes are a major type of glial cells that have essential functions in development and homeostasis of the central nervous system (CNS). Immature astrocytes in the developing CNS support neuronal maturation and possess neural-stem-cell-like properties. Mature astrocytes partially lose these functions but gain new functions essential for adult CNS homeostasis. In pathological conditions, astrocytes become "reactive", which disrupts their mature homeostatic functions and reactivates some immature astrocyte-like properties, suggesting a partial reversal of astrocyte maturation. The loss of homeostatic astrocyte functions contributes to the pathogenesis of various neurological conditions, and therefore activating maturation-promoting mechanisms may be a promising therapeutic strategy to restore homeostasis. Manipulating the mechanisms underlying astrocyte maturation might also allow to facilitate CNS regeneration by enhancing developmental functions of adult astrocytes. However, such therapeutic strategies are still some distance away because of our limited understanding of astrocyte differentiation and maturation, due to biological and technical challenges, including the high degree of similarity of astrocytes with neural stem cells and the shortcomings of astrocyte markers. Current advances in systems biology have a huge potential to overcome these challenges. Recent transcriptomic analyses have already revealed new astrocyte markers and new regulators of astrocyte differentiation. However, the epigenomic changes that presumably occur during astrocyte differentiation remain an important, largely unexplored area for future research. Emerging technologies such as CRISPR/Cas9-based functional screens will further improve our understanding of the mechanisms underlying astrocyte differentiation. This may open up new clinical approaches to restore homeostasis in neurological disorders and/or promote CNS regeneration. This article is categorized under: Neurological Diseases > Genetics/Genomics/Epigenetics Neurological Diseases > Stem Cells and Development Neurological Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Michael Lattke
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London, UK
| | - Francois Guillemot
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London, UK
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Zhou M, Tao X, Sui M, Cui M, Liu D, Wang B, Wang T, Zheng Y, Luo J, Mu Y, Wan F, Zhu LQ, Zhang B. Reprogramming astrocytes to motor neurons by activation of endogenous Ngn2 and Isl1. Stem Cell Reports 2021; 16:1777-1791. [PMID: 34171285 PMCID: PMC8282467 DOI: 10.1016/j.stemcr.2021.05.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/27/2021] [Accepted: 05/27/2021] [Indexed: 12/13/2022] Open
Abstract
Central nervous system injury and neurodegenerative diseases cause irreversible loss of neurons. Overexpression of exogenous specific transcription factors can reprogram somatic cells into functional neurons for regeneration and functional reconstruction. However, these practices are potentially problematic due to the integration of vectors into the host genome. Here, we showed that the activation of endogenous genes Ngn2 and Isl1 by CRISPRa enabled reprogramming of mouse spinal astrocytes and embryonic fibroblasts to motor neurons. These induced neurons showed motor neuronal morphology and exhibited electrophysiological activities. Furthermore, astrocytes in the spinal cord of the adult mouse can be converted into motor neurons by this approach with high efficiency. These results demonstrate that the activation of endogenous genes is sufficient to induce astrocytes into functional motor neurons in vitro and in vivo. This direct neuronal reprogramming approach may provide a novel potential therapeutic strategy for treating neurodegenerative diseases and spinal cord injury.
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Affiliation(s)
- Meiling Zhou
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoqing Tao
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Wuhan Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan 430056, China
| | - Ming Sui
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Mengge Cui
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Dan Liu
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Beibei Wang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ting Wang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yunjie Zheng
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Juan Luo
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yangling Mu
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Feng Wan
- Department of Neurosurgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ling-Qiang Zhu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Bin Zhang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China; Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Huazhong University of Science and Technology, Wuhan 430030, China.
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Pruvost M, Moyon S. Oligodendroglial Epigenetics, from Lineage Specification to Activity-Dependent Myelination. Life (Basel) 2021; 11:62. [PMID: 33467699 PMCID: PMC7830029 DOI: 10.3390/life11010062] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/08/2021] [Accepted: 01/10/2021] [Indexed: 12/25/2022] Open
Abstract
Oligodendroglial cells are the myelinating cells of the central nervous system. While myelination is crucial to axonal activity and conduction, oligodendrocyte progenitor cells and oligodendrocytes have also been shown to be essential for neuronal support and metabolism. Thus, a tight regulation of oligodendroglial cell specification, proliferation, and myelination is required for correct neuronal connectivity and function. Here, we review the role of epigenetic modifications in oligodendroglial lineage cells. First, we briefly describe the epigenetic modalities of gene regulation, which are known to have a role in oligodendroglial cells. We then address how epigenetic enzymes and/or marks have been associated with oligodendrocyte progenitor specification, survival and proliferation, differentiation, and finally, myelination. We finally mention how environmental cues, in particular, neuronal signals, are translated into epigenetic modifications, which can directly influence oligodendroglial biology.
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Affiliation(s)
| | - Sarah Moyon
- Neuroscience Initiative Advanced Science Research Center, CUNY, 85 St Nicholas Terrace, New York, NY 10031, USA;
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Brenner M, Messing A. Regulation of GFAP Expression. ASN Neuro 2021; 13:1759091420981206. [PMID: 33601918 PMCID: PMC7897836 DOI: 10.1177/1759091420981206] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/12/2022] Open
Abstract
Expression of the GFAP gene has attracted considerable attention because its onset is a marker for astrocyte development, its upregulation is a marker for reactive gliosis, and its predominance in astrocytes provides a tool for their genetic manipulation. The literature on GFAP regulation is voluminous, as almost any perturbation of development or homeostasis in the CNS will lead to changes in its expression. In this review, we limit our discussion to mechanisms proposed to regulate GFAP synthesis through a direct interaction with its gene or mRNA. Strengths and weaknesses of the supportive experimental findings are described, and suggestions made for additional studies. This review covers 15 transcription factors, DNA and histone methylation, and microRNAs. The complexity involved in regulating the expression of this intermediate filament protein suggests that GFAP function may vary among both astrocyte subtypes and other GFAP-expressing cells, as well as during development and in response to perturbations.
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Affiliation(s)
- Michael Brenner
- Department of Neurobiology, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Albee Messing
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
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Kandilya D, Shyamasundar S, Singh DK, Banik A, Hande MP, Stünkel W, Chong YS, Dheen ST. High glucose alters the DNA methylation pattern of neurodevelopment associated genes in human neural progenitor cells in vitro. Sci Rep 2020; 10:15676. [PMID: 32973238 PMCID: PMC7518427 DOI: 10.1038/s41598-020-72485-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/28/2020] [Indexed: 12/13/2022] Open
Abstract
Maternal diabetes alters the global epigenetic mechanisms and expression of genes involved in neural tube development in mouse embryos. Since DNA methylation is a critical epigenetic mechanism that regulates gene functions, gene-specific DNA methylation alterations were estimated in human neural progenitor cells (hNPCs) exposed to high glucose (HG) in the present study. The DNA methylation pattern of genes involved in several signalling pathways including axon guidance (SLIT1-ROBO2 pathway), and Hippo pathway (YAP and TAZ) was altered in hNPCs exposed to HG. The expression levels of SLIT1-ROBO2 pathways genes (including its effectors, SRGAP1 and CDC42) which mediates diverse cellular processes such as proliferation, neurogenesis and axon guidance, and Hippo pathway genes (YAP and TAZ) which regulates proliferation, stemness, differentiation and organ size were downregulated in hNPCs exposed to HG. A recent report suggests a possible cross-talk between SLIT1-ROBO2 and TAZ via CDC42, a mediator of actin dynamics. Consistent with this, SLIT1 knockdown downregulated the expression of its effectors and TAZ in hNPCs, suggesting that HG perturbs the cross-talk between SLIT1-ROBO2 and TAZ in hNPCs. Overall, this study demonstrates that HG epigenetically alters the SLIT1-ROBO2 and Hippo signalling pathways in hNPCs, forming the basis for neurodevelopmental disorders in offspring of diabetic pregnancy.
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Affiliation(s)
- Deepika Kandilya
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Level 4, Singapore, 117594, Singapore
| | - Sukanya Shyamasundar
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Level 4, Singapore, 117594, Singapore
| | - Dhiraj Kumar Singh
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Level 4, Singapore, 117594, Singapore
| | - Avijit Banik
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Level 4, Singapore, 117594, Singapore
| | - Manoor Prakash Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Walter Stünkel
- Experimental Drug Development Centre, Agency for Science, Technology and Research, Singapore, Singapore
| | - Yap Seng Chong
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - S Thameem Dheen
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Level 4, Singapore, 117594, Singapore.
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7
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Arthur-Farraj P, Moyon S. DNA methylation in Schwann cells and in oligodendrocytes. Glia 2020; 68:1568-1583. [PMID: 31958184 DOI: 10.1002/glia.23784] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/17/2019] [Accepted: 01/10/2020] [Indexed: 12/12/2022]
Abstract
DNA methylation is one of many epigenetic marks, which directly modifies base residues, usually cytosines, in a multiple-step cycle. It has been linked to the regulation of gene expression and alternative splicing in several cell types, including during cell lineage specification and differentiation processes. DNA methylation changes have also been observed during aging, and aberrant methylation patterns have been reported in several neurological diseases. We here review the role of DNA methylation in Schwann cells and oligodendrocytes, the myelin-forming glia of the peripheral and central nervous systems, respectively. We first address how methylation and demethylation are regulating myelinating cells' differentiation during development and repair. We then mention how DNA methylation dysregulation in diseases and cancers could explain their pathogenesis by directly influencing myelinating cells' proliferation and differentiation capacities.
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Affiliation(s)
- Peter Arthur-Farraj
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Sarah Moyon
- Neuroscience Initiative Advanced Science Research Center, CUNY, New York, New York
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Boni JL, Kahanovitch U, Nwaobi SE, Floyd CL, Olsen ML. DNA methylation: A mechanism for sustained alteration of KIR4.1 expression following central nervous system insult. Glia 2020; 68:1495-1512. [PMID: 32068308 PMCID: PMC8665281 DOI: 10.1002/glia.23797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 12/22/2022]
Abstract
Kir4.1, a glial-specific inwardly rectifying potassium channel, is implicated in astrocytic maintenance of K+ homeostasis. Underscoring the role of Kir4.1 in central nervous system (CNS) functioning, genetic mutations in KCNJ10, the gene which encodes Kir4.1, causes seizures, ataxia and developmental disability in humans. Kir4.1 protein and mRNA loss are consistently observed in CNS injury and neurological diseases linked to hyperexcitability and neuronal dysfunction, leading to the notion that Kir4.1 represents an attractive therapeutic target. Despite this, little is understood regarding the mechanisms that underpin this downregulation. Previous work by our lab revealed that DNA hypomethylation of the Kcnj10 gene functions to regulate mRNA levels during astrocyte maturation whereas hypermethylation in vitro led to decreased promoter activity. In the present study, we utilized two vastly different injury models with known acute and chronic loss of Kir4.1 protein and mRNA to evaluate the methylation status of Kcnj10 as a candidate molecular mechanism for reduced transcription and subsequent protein loss. Examining whole hippocampal tissue and isolated astrocytes, in a lithium-pilocarpine model of epilepsy, we consistently identified hypermethylation of CpG island two, which resides in the large intronic region spanning the Kcnj10 gene. Strikingly similar results were observed using the second injury paradigm, a fifth cervical (C5) vertebral hemi-contusion model of spinal cord injury. Our previous work indicates the same gene region is significantly hypomethylated when transcription increases during astrocyte maturation. Our results suggest that DNA methylation can bidirectionally modulate Kcnj10 transcription and may represent a targetable molecular mechanism for the restoring astroglial Kir4.1 expression following CNS insult.
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Affiliation(s)
- Jessica L Boni
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, Virginia
| | - Uri Kahanovitch
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, Virginia
| | - Sinifunanya E Nwaobi
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Division of Pediatric Neurology, UCLA Mattel Children's Hospital, University of California Los Angeles, Los Angeles, California
| | - Candace L Floyd
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Physical Medicine and Rehabilitation, University of Utah Health, Salt Lake City, Utah
| | - Michelle L Olsen
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, Virginia
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Liu Y, Wang M, Marcora EM, Zhang B, Goate AM. Promoter DNA hypermethylation - Implications for Alzheimer's disease. Neurosci Lett 2019; 711:134403. [PMID: 31351091 PMCID: PMC6759378 DOI: 10.1016/j.neulet.2019.134403] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 07/12/2019] [Accepted: 07/23/2019] [Indexed: 12/31/2022]
Abstract
Recent methylome-wide association studies (MWAS) in humans have solidified the concept that aberrant DNA methylation is associated with Alzheimer's disease (AD). We summarize these findings to improve the understanding of mechanisms governing DNA methylation pertinent to transcriptional regulation, with an emphasis of AD-associated promoter DNA hypermethylation, which establishes an epigenetic barrier for transcriptional activation. By considering brain cell type specific expression profiles that have been published only for non-demented individuals, we detail functional activities of selected neuron, microglia, and astrocyte-enriched genes (AGAP2, DUSP6 and GPR37L1, respectively), which are DNA hypermethylated at promoters in AD. We highlight future directions in MWAS including experimental confirmation, functional relevance to AD, cell type-specific temporal characterization, and mechanism investigation.
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Affiliation(s)
- Yiyuan Liu
- Department of Neuroscience and Department of Genetics and Genomic Sciences, Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY, 10029, USA
| | - Minghui Wang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY, 10029, USA.
| | - Edoardo M Marcora
- Department of Neuroscience and Department of Genetics and Genomic Sciences, Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY, 10029, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY, 10029, USA
| | - Alison M Goate
- Department of Neuroscience and Department of Genetics and Genomic Sciences, Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY, 10029, USA
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Liang J, Yang F, Zhao L, Bi C, Cai B. Physiological and pathological implications of 5-hydroxymethylcytosine in diseases. Oncotarget 2018; 7:48813-48831. [PMID: 27183914 PMCID: PMC5217052 DOI: 10.18632/oncotarget.9281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/19/2016] [Indexed: 12/11/2022] Open
Abstract
Gene expression is the prerequisite of proteins. Diverse stimuli result in alteration of gene expression profile by base substitution for quite a long time. However, during the past decades, accumulating studies proved that bases modification is involved in this process. CpG islands (CGIs) are DNA fragments enriched in CpG repeats which mostly locate in promoters. They are frequently modified, methylated in most conditions, thereby suggesting a role of methylation in profiling gene expression. DNA methylation occurs in many conditions, such as cancer, embryogenesis, nervous system diseases etc. Recently, 5-hydroxymethylcytosine (5hmC), the product of 5-methylcytosine (5mC) demethylation, is emerging as a novel demethylation marker in many disorders. Consistently, conversion of 5mC to 5hmC has been proved in many studies. Here, we reviewed recent studies concerning demethylation via 5hmC conversion in several conditions and progress of therapeutics-associated with it in clinic. We aimed to unveil its physiological and pathological significance in diseases and to provide insight into its clinical application potential.
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Affiliation(s)
- Jing Liang
- Department of Pharmacology, Harbin Medical University (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, China
| | - Fan Yang
- Department of Pharmacology, Harbin Medical University (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, China
| | - Liang Zhao
- Department of Pharmacology, Harbin Medical University (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, China
| | - Chongwei Bi
- Department of Pharmacology, Harbin Medical University (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, China
| | - Benzhi Cai
- Department of Pharmacology, Harbin Medical University (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, China.,Institute of Clinical Pharmacy and Medicine, Academics of Medical Sciences of Heilongjiang Province, Harbin, China
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11
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Voelker P, Sheese BE, Rothbart MK, Posner MI. Methylation polymorphism influences practice effects in children during attention tasks. Cogn Neurosci 2017; 8:72-84. [PMID: 27050482 PMCID: PMC5605136 DOI: 10.1080/17588928.2016.1170006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Epigenetic mechanisms mediate the influence of experience on gene expression. Methylation is a principal method for inducing epigenetic effects on DNA. In this paper, we examine alleles of the methylenetetrahydrofolate reductase (MTHFR) gene that vary enzyme activity, altering the availability of the methyl donor and thus changing the efficiency of methylation. We hypothesized that alleles of the MTHFR gene would influence behavior in an attention-related task in conjunction with genes known to influence attention. We found that seven-year-old children homozygous for the C allele of MTHFR in interaction with the catechol O-methyltransferase (COMT) gene showed greater improvement in overall reaction time (RT) and in conflict resolution with practice on the Attention Network Test (ANT). This finding indicates that methylation may operate on or through genes that influence executive network operation. However, MTHFR T allele carriers showed faster overall RT and conflict resolution. Some children showed an initial improvement in ANT RT followed by a decline in performance, and we found that alleles of the dopamine beta-hydroxylase (DBH) gene were related to this performance decline. These results suggest a genetic dissociation between improvement while learning a skill and reduction in performance with continued practice.
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Affiliation(s)
| | - Brad E Sheese
- b Psychology , Illinois Wesleyan University , Bloomington , USA
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Emery B, Lu QR. Transcriptional and Epigenetic Regulation of Oligodendrocyte Development and Myelination in the Central Nervous System. Cold Spring Harb Perspect Biol 2015; 7:a020461. [PMID: 26134004 DOI: 10.1101/cshperspect.a020461] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Central nervous system (CNS) myelination by oligodendrocytes (OLs) is a highly orchestrated process involving well-defined steps from specification of neural stem cells into proliferative OL precursors followed by terminal differentiation and subsequent maturation of these precursors into myelinating OLs. These specification and differentiation processes are mediated by profound global changes in gene expression, which are in turn subject to control by both extracellular signals and regulatory networks intrinsic to the OL lineage. Recently, basic transcriptional mechanisms that control OL differentiation and myelination have begun to be elucidated at the molecular level and on a genome scale. The interplay between transcription factors activated by differentiation-promoting signals and master regulators likely exerts a crucial role in controlling stage-specific progression of the OL lineage. In this review, we describe the current state of knowledge regarding the transcription factors and the epigenetic programs including histone methylation, acetylation, chromatin remodeling, micro-RNAs, and noncoding RNAs that regulate development of OLs and myelination.
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Affiliation(s)
- Ben Emery
- Department of Anatomy and Neurobiology, University of Melbourne, Victoria 3010, Australia Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria 3010, Australia
| | - Q Richard Lu
- Department of Pediatrics, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
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13
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Ma Q, Zhang L. Epigenetic programming of hypoxic-ischemic encephalopathy in response to fetal hypoxia. Prog Neurobiol 2014; 124:28-48. [PMID: 25450949 DOI: 10.1016/j.pneurobio.2014.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 08/14/2014] [Accepted: 11/02/2014] [Indexed: 12/13/2022]
Abstract
Hypoxia is a major stress to the fetal development and may result in irreversible injury in the developing brain, increased risk of central nervous system (CNS) malformations in the neonatal brain and long-term neurological complications in offspring. Current evidence indicates that epigenetic mechanisms may contribute to the development of hypoxic/ischemic-sensitive phenotype in the developing brain in response to fetal stress. However, the causative cellular and molecular mechanisms remain elusive. In the present review, we summarize the recent findings of epigenetic mechanisms in the development of the brain and their roles in fetal hypoxia-induced brain developmental malformations. Specifically, we focus on DNA methylation and active demethylation, histone modifications and microRNAs in the regulation of neuronal and vascular developmental plasticity, which may play a role in fetal stress-induced epigenetic programming of hypoxic/ischemic-sensitive phenotype in the developing brain.
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Affiliation(s)
- Qingyi Ma
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Lubo Zhang
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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14
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Nwaobi SE, Lin E, Peramsetty SR, Olsen ML. DNA methylation functions as a critical regulator of Kir4.1 expression during CNS development. Glia 2014; 62:411-27. [PMID: 24415225 DOI: 10.1002/glia.22613] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 10/29/2013] [Accepted: 11/21/2013] [Indexed: 12/22/2022]
Abstract
Kir4.1, a glial-specific K+ channel, is critical for normal CNS development. Studies using both global and glial-specific knockout of Kir4.1 reveal abnormal CNS development with the loss of the channel. Specifically, Kir4.1 knockout animals are characterized by ataxia, severe hypomyelination, and early postnatal death. Additionally, Kir4.1 has emerged as a key player in several CNS diseases. Notably, decreased Kir4.1 protein expression occurs in several human CNS pathologies including CNS ischemic injury, spinal cord injury, epilepsy, ALS, and Alzheimer's disease. Despite the emerging significance of Kir4.1 in normal and pathological conditions, its mechanisms of regulation are unknown. Here, we report the first epigenetic regulation of a K+ channel in the CNS. Robust developmental upregulation of Kir4.1 expression in rats is coincident with reductions in DNA methylation of the Kir4.1 gene, KCNJ10. Chromatin immunoprecipitation reveals a dynamic interaction between KCNJ10 and DNA methyltransferase 1 during development. Finally, demethylation of the KCNJ10 promoter is necessary for transcription. These findings indicate DNA methylation is a key regulator of Kir4.1 transcription. Given the essential role of Kir4.1 in normal CNS development, understanding the regulation of this K+ channel is critical to understanding normal glial biology.
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Affiliation(s)
- Sinifunanya E Nwaobi
- Department of Cell, Developmental and Integrative Biology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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15
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Moore LD, Le T, Fan G. DNA methylation and its basic function. Neuropsychopharmacology 2013; 38:23-38. [PMID: 22781841 PMCID: PMC3521964 DOI: 10.1038/npp.2012.112] [Citation(s) in RCA: 2364] [Impact Index Per Article: 214.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/07/2012] [Accepted: 05/08/2012] [Indexed: 02/06/2023]
Abstract
In the mammalian genome, DNA methylation is an epigenetic mechanism involving the transfer of a methyl group onto the C5 position of the cytosine to form 5-methylcytosine. DNA methylation regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factor(s) to DNA. During development, the pattern of DNA methylation in the genome changes as a result of a dynamic process involving both de novo DNA methylation and demethylation. As a consequence, differentiated cells develop a stable and unique DNA methylation pattern that regulates tissue-specific gene transcription. In this chapter, we will review the process of DNA methylation and demethylation in the nervous system. We will describe the DNA (de)methylation machinery and its association with other epigenetic mechanisms such as histone modifications and noncoding RNAs. Intriguingly, postmitotic neurons still express DNA methyltransferases and components involved in DNA demethylation. Moreover, neuronal activity can modulate their pattern of DNA methylation in response to physiological and environmental stimuli. The precise regulation of DNA methylation is essential for normal cognitive function. Indeed, when DNA methylation is altered as a result of developmental mutations or environmental risk factors, such as drug exposure and neural injury, mental impairment is a common side effect. The investigation into DNA methylation continues to show a rich and complex picture about epigenetic gene regulation in the central nervous system and provides possible therapeutic targets for the treatment of neuropsychiatric disorders.
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Affiliation(s)
- Lisa D Moore
- Interdepartmental Program in Neuroscience and Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Thuc Le
- Interdepartmental Program in Neuroscience and Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Guoping Fan
- Interdepartmental Program in Neuroscience and Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
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16
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Abstract
There are numerous examples of enduring effects of early experience on gene transcription and neural function. We review the emerging evidence for epigenetics as a candidate mechanism for such effects. There is now evidence that intracellular signals activated by environmental events can directly modify the epigenetic state of the genome, including CpG methylation, histone modifications and microRNAs. We suggest that this process reflects an activity-dependent epigenetic plasticity at the level of the genome, comparable with that observed at the synapse. This epigenetic plasticity mediates neuronal differentiation and phenotypic plasticity, including that associated with learning and memory. Altered epigenetic states are also associated with the risk for and expression of mental disorders. In a broader context, these studies define a biological basis for the interplay between environmental signals and the genome in the regulation of individual differences in behavior, cognition and physiology, as well as the risk for psychopathology.
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Affiliation(s)
- Judy Sng
- Integrative Neuroscience Program, Singapore Institute for Clinical Sciences, 30 Medial Drive, Singapore.
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17
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Caldji C, Hellstrom IC, Zhang TY, Diorio J, Meaney MJ. Environmental regulation of the neural epigenome. FEBS Lett 2011; 585:2049-58. [PMID: 21420958 DOI: 10.1016/j.febslet.2011.03.032] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 03/14/2011] [Accepted: 03/14/2011] [Indexed: 01/10/2023]
Abstract
Parental effects are a major source of phenotypic plasticity. Moreover, there is evidence from studies with a wide range of species that the relevant parental signals are influenced by the quality of the parental environment. The link between the quality of the environment and the nature of the parental signal is consistent with the idea that parental effects, whether direct or indirect, might serve to influence the phenotype of the offspring in a manner that is consistent with the prevailing environmental demands. In this review we explore recent studies from the field of 'environmental epigenetics' that suggest that (1) DNA methylation states are far more variable than once thought and that, at least within specific regions of the genome, there is evidence for both demethylation and remethylation in post-mitotic cells and (2) that such remodeling of DNA methylation can occur in response to environmentally-driven, intracellular signaling pathways. Thus, studies of variation in mother-offspring interactions in rodents suggest that parental signals operate during pre- and/or post-natal life to influence the DNA methylation state at specific regions of the genome leading to sustained changes in gene expression and function. We suggest that DNA methylation is a candidate mechanism for parental effects on phenotypic variation.
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Affiliation(s)
- Christian Caldji
- Sackler Program for Epigenetics and Psychobiology at McGill University, Douglas Mental Health University Institute, McGill University, Montréal, Canada
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18
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Bagot RC, Meaney MJ. Epigenetics and the biological basis of gene x environment interactions. J Am Acad Child Adolesc Psychiatry 2010; 49:752-71. [PMID: 20643310 DOI: 10.1016/j.jaac.2010.06.001] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 05/31/2010] [Accepted: 06/07/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Child and adolescent psychiatry is rife with examples of the sustained effects of early experience on brain function. The study of behavioral genetics provides evidence for a relation between genomic variation and personality and with the risk for psychopathology. A pressing challenge is that of conceptually integrating findings from genetics into the study of personality without regressing to arguments concerning the relative importance of genomic variation versus nongenomic or environmental influences. METHOD Epigenetics refers to functionally relevant modifications to the genome that do not involve a change in nucleotide sequence. This review examines epigenetics as a candidate biological mechanism for gene x environment interactions, with a focus on environmental influences that occur during early life and that yield sustained effects on neural development and function. RESULTS The studies reviewed suggest that epigenetic remodeling occurs in response to the environmental activation of cellular signalling pathways associated with synaptic plasticity, epigenetic marks are actively remodeled during early development in response to environmental events that regulate neural development and function, and epigenetic marks are subject to remodeling by environmental influences even at later stages in development. CONCLUSION Epigenetic remodeling might serve as an ideal mechanism for phenotypic plasticity--the process whereby the environment interacts with the genome to produce individual differences in the expression of specific traits.
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Affiliation(s)
- Rosemary C Bagot
- Sackler Program for Epigenetics and Psychobiology, McGill University and Douglas Mental Health University Institute, Montreal, Canada
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19
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MacDonald JL, Roskams AJ. Epigenetic regulation of nervous system development by DNA methylation and histone deacetylation. Prog Neurobiol 2009; 88:170-83. [PMID: 19554713 DOI: 10.1016/j.pneurobio.2009.04.002] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Alterations in the epigenetic modulation of gene expression have been implicated in several developmental disorders, cancer, and recently, in a variety of mental retardation and complex psychiatric disorders. A great deal of effort is now being focused on why the nervous system may be susceptible to shifts in activity of epigenetic modifiers. The answer may simply be that the mammalian nervous system must first produce the most complex degree of developmental patterning in biology and hardwire cells functionally in place postnatally, while still allowing for significant plasticity in order for the brain to respond to a rapidly changing environment. DNA methylation and histone deacetylation are two major epigenetic modifications that contribute to the stability of gene expression states. Perturbing DNA methylation, or disrupting the downstream response to DNA methylation - methyl-CpG-binding domain proteins (MBDs) and histone deacetylases (HDACs) - by genetic or pharmacological means, has revealed a critical requirement for epigenetic regulation in brain development, learning, and mature nervous system stability, and has identified the first distinct gene sets that are epigenetically regulated within the nervous system. Epigenetically modifying chromatin structure in response to different stimuli appears to be an ideal mechanism to generate continuous cellular diversity and coordinate shifts in gene expression at successive stages of brain development - all the way from deciding which kind of a neuron to generate, through to how many synapses a neuron can support. Here, we review the evidence supporting a role for DNA methylation and histone deacetylation in nervous system development and mature function, and present a basis from which to understand how the clinical use of HDAC inhibitors may impact nervous system function.
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Affiliation(s)
- Jessica L MacDonald
- Life Sciences Institute, Department of Zoology, University of British Columbia, BC, V6T 1Z3, Vancouver, Canada
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20
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Spulber S, Bartfai T, Schultzberg M. IL-1/IL-1ra balance in the brain revisited - evidence from transgenic mouse models. Brain Behav Immun 2009; 23:573-9. [PMID: 19258032 DOI: 10.1016/j.bbi.2009.02.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 02/09/2009] [Accepted: 02/19/2009] [Indexed: 01/07/2023] Open
Abstract
The interleukin-1 (IL-1) family is unique in its including an endogenous antagonist of the IL-1 receptor (IL-1ra). IL-1ra has been shown to antagonise IL-1 signalling so effectively, that it came into clinical use within a few years from its discovery. Although barely detectable in the normal brain, IL-1 is dramatically upregulated during neuroinflammation, and also displays peaks of expression in the brain during development, as well as following the induction of long-term potentiation. IL-1 has been ascribed a central role in neuroinflammation accompanying ageing and age-related neurodegenerative conditions. Several experimental models based on genetically modified mice have been used in order to address the role of IL-1 in neurodegeneration and neuroprotection. Most of the findings here are based on the experiments involving a transgenic mouse strain with brain-directed overexpression of human IL-1ra, in which the balance between IL-1 and IL-1ra is permanently tipped towards inhibiting IL-1 signalling. The developmental effects of IL-1 are evident in the altered brain morphology in adult transgenic mice. In addition, IL-1 appears to be central in regulating the elasticity of the brain response to injury. Thus, a number of lines of evidence support the essential role played by IL-1 in development, plasticity, and physiological brain function.
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Affiliation(s)
- S Spulber
- Karolinska Institutet, Dept. of Neurobiology, Care Sciences and Society, Stockholm, Sweden.
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21
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Transcriptional regulation of neuronal differentiation: the epigenetic layer of complexity. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2008; 1779:432-7. [PMID: 18674649 DOI: 10.1016/j.bbagrm.2008.07.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 07/11/2008] [Accepted: 07/18/2008] [Indexed: 11/22/2022]
Abstract
The transcriptional programs of neural progenitor cells change dynamically during neurogenesis, a process regulated by both intrinsic and extrinsic factors. Although many of the transcription factors required for neuronal differentiation have long been identified, we are only at the brink of understanding how epigenetic mechanisms influence transcriptional activity and the accessibility of transcription factors to bind consensus cis-elements. Herein, we delineate the chief epigenetic modifications and the machinery responsible for these alterations. Further, we review the epigenetic modifications presently known to participate in the maintenance of the neural progenitor cell state and in the regulation of neuronal differentiation.
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22
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Novikova SI, He F, Bai J, Cutrufello NJ, Lidow MS, Undieh AS. Maternal cocaine administration in mice alters DNA methylation and gene expression in hippocampal neurons of neonatal and prepubertal offspring. PLoS One 2008; 3:e1919. [PMID: 18382688 PMCID: PMC2271055 DOI: 10.1371/journal.pone.0001919] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Accepted: 02/11/2008] [Indexed: 02/03/2023] Open
Abstract
Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8–19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI2 microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression analysis, were evaluated in hippocampal pyramidal neurons excised by laser capture microdissection. Following maternal cocaine exposure, global DNA methylation was significantly decreased at P3 and increased at P30. Among the 492 CGIs whose methylation was significantly altered by cocaine at P3, 34% were hypermethylated while 66% were hypomethylated. Several of these CGIs contained promoter regions for genes implicated in crucial cellular functions. Endogenous expression of selected genes linked to the abnormally methylated CGIs was correspondingly decreased or increased by as much as 4–19-fold. By P30, some of the cocaine-associated effects at P3 endured, reversed to opposite directions, or disappeared. Further, additional sets of abnormally methylated targets emerged at P30 that were not observed at P3. Taken together, these observations indicate that maternal cocaine exposure during the second and third trimesters of gestation could produce potentially profound structural and functional modifications in the epigenomic programs of neonatal and prepubertal mice.
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Affiliation(s)
- Svetlana I. Novikova
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, Philadelphia, Pennsylvania, United States of America
| | - Fang He
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Jie Bai
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Nicholas J. Cutrufello
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Michael S. Lidow
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Ashiwel S. Undieh
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, Philadelphia, Pennsylvania, United States of America
- * To whom correspondence should be addressed. E-mail:
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23
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Liu L, van Groen T, Kadish I, Tollefsbol TO. DNA methylation impacts on learning and memory in aging. Neurobiol Aging 2007; 30:549-60. [PMID: 17850924 PMCID: PMC2656583 DOI: 10.1016/j.neurobiolaging.2007.07.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/19/2007] [Accepted: 07/24/2007] [Indexed: 12/20/2022]
Abstract
Learning and memory are two of the fundamental cognitive functions that confer us the ability to accumulate knowledge from our experiences. Although we use these two mental skills continuously, understanding the molecular basis of learning and memory is very challenging. Methylation modification of DNA is an epigenetic mechanism that plays important roles in regulating gene expression, which is one of the key processes underlying the functions of cells including neurons. Interestingly, a genome-wide decline in DNA methylation occurs in the brain during normal aging, which coincides with a functional decline in learning and memory with age. It has been speculated that DNA methylation in neurons might be involved in memory coding. However, direct evidence supporting the role of DNA methylation in memory formation is still under investigation. This particular function of DNA methylation has not drawn wide attention despite several important studies that have provided supportive evidence for the epigenetic control of memory formation. To facilitate further exploration of the epigenetic basis of memory function, we will review existing studies on DNA methylation that are related to the development and function of the nervous system. We will focus on studies illustrating how DNA methylation regulates neural activities and memory formation via the control of gene expression in neurons, and relate these studies to various age-related neurological disorders that affect cognitive functions.
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Affiliation(s)
- Liang Liu
- Department of Biology, University of Alabama at Birmingham, 175 Campbell Hall, 1300 University Boulevard, Birmingham, AL 35294-1170, USA.
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24
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Nguyen S, Meletis K, Fu D, Jhaveri S, Jaenisch R. Ablation of de novo DNA methyltransferase Dnmt3a in the nervous system leads to neuromuscular defects and shortened lifespan. Dev Dyn 2007; 236:1663-76. [PMID: 17477386 DOI: 10.1002/dvdy.21176] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
DNA methylation is an epigenetic mechanism involved in gene regulation and implicated in the functioning of the nervous system. The de novo DNA methyltransferase Dnmt3a is expressed in neurons, but its specific role has not been clarified. Dnmt3a is activated around embryonic day 10.5 in mouse neuronal precursor cells and remains active in postmitotic neurons in the adult. We assessed the role of neuronal Dnmt3a by conditional gene targeting. Mice lacking functional Dnmt3a in the nervous system were born healthy, but degenerated in adulthood and died prematurely. Mutant mice were hypoactive, walked abnormally, and underperformed on tests of neuromuscular function and motor coordination. Loss of Dnmt3a also led to fewer motor neurons in the hypoglossal nucleus and more fragmented endplates in neuromuscular junctions of the diaphragm muscle. Our results implicate a role for Dnmt3a in the neuromuscular control of motor movement.
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Affiliation(s)
- Suzanne Nguyen
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA
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25
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Kondo T. Epigenetic alchemy for cell fate conversion. Curr Opin Genet Dev 2006; 16:502-7. [PMID: 16844365 DOI: 10.1016/j.gde.2006.07.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 07/05/2006] [Indexed: 12/15/2022]
Abstract
Recent progress in neural stem cell research shows that a number of extrinsic factors and intracellular mechanisms, including epigenetic modifications, are involved in the self-renewal of neural stem cells and in neuronal and glial differentiation. Remarkably, there is increasing evidence that the remodeling of chromatin structure and the alteration of epigenetic marks, including histone methylation and acetylation and DNA methylation, can cause committed cells to convert from one fate to another, and such converted cells are functional when transplanted in vivo. Thus, epigenetic research might generate the alchemy required to convert any non-neural stem cells into functional neural stem cells, which are few and difficult to extract from the adult central nervous system.
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Affiliation(s)
- Toru Kondo
- Laboratory for Cell Lineage Modulation, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
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26
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Fan G, Martinowich K, Chin MH, He F, Fouse SD, Hutnick L, Hattori D, Ge W, Shen Y, Wu H, ten Hoeve J, Shuai K, Sun YE. DNA methylation controls the timing of astrogliogenesis through regulation of JAK-STAT signaling. Development 2005; 132:3345-56. [PMID: 16014513 DOI: 10.1242/dev.01912] [Citation(s) in RCA: 338] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
DNA methylation is a major epigenetic factor that has been postulated to regulate cell lineage differentiation. We report here that conditional gene deletion of the maintenance DNA methyltransferase I (Dnmt1) in neural progenitor cells (NPCs) results in DNA hypomethylation and precocious astroglial differentiation. The developmentally regulated demethylation of astrocyte marker genes as well as genes encoding the crucial components of the gliogenic JAK-STAT pathway is accelerated in Dnmt1-/- NPCs. Through a chromatin remodeling process, demethylation of genes in the JAK-STAT pathway leads to an enhanced activation of STATs, which in turn triggers astrocyte differentiation. Our study suggests that during the neurogenic period, DNA methylation inhibits not only astroglial marker genes but also genes that are essential for JAK-STAT signaling. Thus, demethylation of these two groups of genes and subsequent elevation of STAT activity are key mechanisms that control the timing and magnitude of astroglial differentiation.
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Affiliation(s)
- Guoping Fan
- Department of Human Genetics, University of California at Los Angeles, 695 Charles Young Drive South, Los Angeles, CA 90095, USA.
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27
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Shimozaki K, Namihira M, Nakashima K, Taga T. Stage- and site-specific DNA demethylation during neural cell development from embryonic stem cells. J Neurochem 2005; 93:432-9. [PMID: 15816866 DOI: 10.1111/j.1471-4159.2005.03031.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation of the transcription factor STAT3 is important for astrocyte differentiation during neural development. Demethylation of the methyl-CpG dinucleotide in the STAT3 binding site in the promoter of the glial fibrillary acidic protein (GFAP) gene, a marker for astrocytes, was previously shown to be a crucial cue for neural progenitors to express this gene in response to astrogenic signals during brain development. In this study, we analyzed the methylation status of the STAT3 binding site in the GFAP gene promoter during neural cell development from mouse embryonic stem (ES) cells in vitro. The CpG dinucleotide in the STAT3 binding site in the GFAP gene promoter exhibited a high incidence of cytidine-methylation in undifferentiated pluripotent ES cells. The high incidence of methylation of this particular cytidine was maintained in ES cell-derived neuroectoderm-like cells, but it underwent demethylation when the neural lineage cells became competent to express GFAP in response to a STAT3 activation signal. In contrast, hypermethylation of the CpG site was maintained in non-neural cells generated from the same ES cells. Progressive demethylation of the STAT3 binding site in the GFAP gene promoter was also observed in primary embryonic neuroepithelial cells during in vitro culture, whereas non-neural cells maintained hypermethylation of this site even after culture. Taken together, these results demonstrate that the astrocyte gene-specific cytidine-demethylation is programmed when neural progenitors from pluripotent cells are committed to a neural lineage that is capable of producing astrocytes.
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Affiliation(s)
- Koji Shimozaki
- Laboratory of Animal Molecular Technology, Research and Education Center for Genetic Information, Nara Institute of Science and Technology, Ikoma, Nara, Japan
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28
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Mastronardi FG, Min W, Wang H, Winer S, Dosch M, Boggs JM, Moscarello MA. Attenuation of Experimental Autoimmune Encephalomyelitis and Nonimmune Demyelination by IFN-β plus Vitamin B12: Treatment to Modify Notch-1/Sonic Hedgehog Balance. THE JOURNAL OF IMMUNOLOGY 2004; 172:6418-26. [PMID: 15128833 DOI: 10.4049/jimmunol.172.10.6418] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Interferon-beta is a mainstay therapy of demyelinating diseases, but its effects are incomplete in human multiple sclerosis and several of its animal models. In this study, we demonstrate dramatic improvements of clinical, histological, and laboratory parameters in in vivo mouse models of demyelinating disease through combination therapy with IFN-beta plus vitamin B(12) cyanocobalamin (B(12)CN) in nonautoimmune primary demyelinating ND4 (DM20) transgenics, and in acute and chronic experimental autoimmune encephalomyelitis in SJL mice. Clinical improvement (p values <0.0001) was paralleled by near normal motor function, reduced astrocytosis, and reduced demyelination. IFN-beta plus B(12)CN enhanced in vivo and in vitro oligodendrocyte maturation. In vivo and in vitro altered expression patterns of reduced Notch-1 and enhanced expression of sonic hedgehog and its receptor were consistent with oligodendrocyte maturation and remyelination. IFN-beta-B(12)CN combination therapy may be promising for the treatment of multiple sclerosis.
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MESH Headings
- Acute Disease
- Animals
- Brain/drug effects
- Brain/metabolism
- Cell Line
- Chronic Disease
- Demyelinating Diseases/genetics
- Demyelinating Diseases/metabolism
- Demyelinating Diseases/prevention & control
- Drug Synergism
- Drug Therapy, Combination
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/prevention & control
- Female
- Hedgehog Proteins
- Humans
- Interferon-beta/therapeutic use
- Mice
- Mice, Inbred Strains
- Mice, Transgenic
- Oligodendroglia/cytology
- Oligodendroglia/drug effects
- Oligodendroglia/metabolism
- Peptide Fragments/biosynthesis
- Receptor, Notch1
- Receptors, Cell Surface/biosynthesis
- Receptors, Cell Surface/metabolism
- Stem Cells/drug effects
- Stem Cells/metabolism
- Trans-Activators/biosynthesis
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription Factors
- Vitamin B 12/therapeutic use
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Affiliation(s)
- Fabrizio G Mastronardi
- Department of Structural Biology and Biochemistry, Hospital for Sick Children, Toronto, Ontario, Canada
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29
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Sun YE, Martinowich K, Ge W. Making and repairing the mammalian brain--signaling toward neurogenesis and gliogenesis. Semin Cell Dev Biol 2003; 14:161-8. [PMID: 12948350 DOI: 10.1016/s1084-9521(03)00007-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Neural stem cells (NSCs) are subscribed extraordinary potential in repair of the damaged nervous system. However, the molecular identity of NSCs has not been established. Most NSC cultures contain large numbers of multipotent, bipotent, and lineage restricted neural progenitors, the majority of which appear to lose neurogenic potential after expansion. This review first discusses the neurogenic to gliogenic switch that is characteristic of progenitor development in vivo and in NSC cultures, and then the cell intrinsic and extrinsic mechanisms regulating the sequential differentiation of neurons and glia. Finally, we discuss potential methods for maintaining the neurogenic potential of NSC cultures after expansion.
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Affiliation(s)
- Y E Sun
- Department of Psychiatry and Behavioral Sciences and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, NPI 48-149, 760 Westwood Plaza, Los Angeles, CA 90024, USA.
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30
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Takizawa T, Nakashima K, Namihira M, Ochiai W, Uemura A, Yanagisawa M, Fujita N, Nakao M, Taga T. DNA methylation is a critical cell-intrinsic determinant of astrocyte differentiation in the fetal brain. Dev Cell 2001; 1:749-58. [PMID: 11740937 DOI: 10.1016/s1534-5807(01)00101-0] [Citation(s) in RCA: 444] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Astrocyte differentiation, which occurs late in brain development, is largely dependent on the activation of a transcription factor, STAT3. We show that astrocytes, as judged by glial fibrillary acidic protein (GFAP) expression, never emerge from neuroepithelial cells on embryonic day (E) 11.5 even when STAT3 is activated, in contrast to E14.5 neuroepithelial cells. A CpG dinucleotide within a STAT3 binding element in the GFAP promoter is highly methylated in E11.5 neuroepithelial cells, but is demethylated in cells responsive to the STAT3 activation signal to express GFAP. This CpG methylation leads to inaccessibility of STAT3 to the binding element. We suggest that methylation of a cell type-specific gene promoter is a pivotal event in regulating lineage specification in the developing brain.
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Affiliation(s)
- T Takizawa
- Department of Cell Fate Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
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Chan MF, Liang G, Jones PA. Relationship between transcription and DNA methylation. Curr Top Microbiol Immunol 2000; 249:75-86. [PMID: 10802939 DOI: 10.1007/978-3-642-59696-4_5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- M F Chan
- Department of Biochemistry and Molecular Biology, University of Southern California/Norris, Comprehensive Cancer Center and Hospital, Los Angeles 90089-9181, USA
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Barresi V, Condorelli DF, Giuffrida Stella AM. GFAP gene methylation in different neural cell types from rat brain. Int J Dev Neurosci 1999; 17:821-8. [PMID: 10593618 DOI: 10.1016/s0736-5748(99)00059-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
It is generally believed that specific demethylation processes take place in the promoter of tissue-specific genes during development. It has been suggested that hypomethylation of the -1500/-1100 domain of the 5' flanking regulatory region of the rat glial fibrillary acidic protein gene may be specific for neuroectodermal derivatives such as neurons and astrocytes. In the present work the methylation status of one of those seven CG sites (the -1176) of the 'neuroectoderm-specific domain' was analyzed. In agreement with the neuroectoderm hypothesis, the -1176 site is highly demethylated in astroglial, oligodendroglial and neuronal cells, but heavily methylated in microglial and fibroblast cells. The three different glial population are derived from the same tissue (cerebral hemispheres of newborn rats) but have a different embryological origin: oligodendrocytes and astrocytes originate from neuroectoderm, while microglia is of mesodermal origin. It is not clear if GFAP-negative neuronal cells maintain such demethylation in the advanced stage of maturation or if they undergo a second phase of de novo methylation. In order to clarify this point we used a subcellular fractionation method which allowed us to separate two different nuclear populations from adult rat cerebral hemispheres: one enriched in neuronal nuclei (called N1) and the other enriched in glial nuclei (N2). A higher methylation level of the -1176 site was detected in the N1 fraction, suggesting the GFAP gene undergo a de novo methylation process during neuronal maturation. This observation is in agreement with recent results showing a de novo methylation of the -1176 site during postnatal brain development. We hypothesize that a DNA demethylation process takes place in neuroectodermal precursor cells and that the -1176 site persists demethylated at the earlier stages of neuronal differentiation (immature neurons) and becomes fully methylated at more advanced stages of differentiation.
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Affiliation(s)
- V Barresi
- Dipartimento di Scienze Chimiche, Facoltà di Medicina, Università di Catania, Italy
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