51
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Targeting G-quadruplex DNA as cognitive function therapy for ATR-X syndrome. Nat Med 2018; 24:802-813. [DOI: 10.1038/s41591-018-0018-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 02/12/2018] [Indexed: 01/08/2023]
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52
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Epigenetics of Circadian Rhythms in Imprinted Neurodevelopmental Disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 157:67-92. [PMID: 29933957 DOI: 10.1016/bs.pmbts.2017.11.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
DNA sequence information alone cannot account for the immense variability between chromosomal alleles within diverse cell types in the brain, whether these differences are observed across time, cell type, or parental origin. The complex control and maintenance of gene expression and modulation are regulated by a multitude of molecular and cellular mechanisms that layer on top of the genetic code. The integration of genetic and environmental signals required for regulating brain development and function is achieved in part by a dynamic epigenetic landscape that includes DNA methylation, histone modifications, and noncoding RNAs. These epigenetic mechanisms establish and maintain core biological processes, including genomic imprinting and entrainment of circadian rhythms. This chapter will focus on how the epigenetic layers of DNA methylation and long, noncoding RNAs interact with circadian rhythms at specific imprinted chromosomal loci associated with the human neurodevelopmental disorders Prader-Willi, Angelman, Kagami-Ogata, and Temple syndromes.
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53
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Sokpor G, Abbas E, Rosenbusch J, Staiger JF, Tuoc T. Transcriptional and Epigenetic Control of Mammalian Olfactory Epithelium Development. Mol Neurobiol 2018. [PMID: 29532253 DOI: 10.1007/s12035-018-0987-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The postnatal mammalian olfactory epithelium (OE) represents a major aspect of the peripheral olfactory system. It is a pseudostratified tissue that originates from the olfactory placode and is composed of diverse cells, some of which are specialized receptor neurons capable of transducing odorant stimuli to afford the perception of smell (olfaction). The OE is known to offer a tractable miniature model for studying the systematic generation of neurons and glia that typify neural tissue development. During OE development, stem/progenitor cells that will become olfactory sensory neurons and/or non-neuronal cell types display fine spatiotemporal expression of neuronal and non-neuronal genes that ensures their proper proliferation, differentiation, survival, and regeneration. Many factors, including transcription and epigenetic factors, have been identified as key regulators of the expression of such requisite genes to permit normal OE morphogenesis. Typically, specific interactive regulatory networks established between transcription and epigenetic factors/cofactors orchestrate histogenesis in the embryonic and adult OE. Hence, investigation of these regulatory networks critical for OE development promises to disclose strategies that may be employed in manipulating the stepwise transition of olfactory precursor cells to become fully differentiated and functional neuronal and non-neuronal cell types. Such strategies potentially offer formidable means of replacing injured or degenerated neural cells as therapeutics for nervous system perturbations. This review recapitulates the developmental cellular diversity of the olfactory neuroepithelium and discusses findings on how the precise and cooperative molecular control by transcriptional and epigenetic machinery is indispensable for OE ontogeny.
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Affiliation(s)
- Godwin Sokpor
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany
| | - Eman Abbas
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany.,Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Joachim Rosenbusch
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany
| | - Jochen F Staiger
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075, Goettingen, Germany
| | - Tran Tuoc
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany. .,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075, Goettingen, Germany.
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54
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Pensold D, Zimmer G. Single-Cell Transcriptomics Reveals Regulators of Neuronal Migration and Maturation During Brain Development. J Exp Neurosci 2018; 12:1179069518760783. [PMID: 29551912 PMCID: PMC5846933 DOI: 10.1177/1179069518760783] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 02/01/2018] [Indexed: 11/22/2022] Open
Abstract
The correct establishment of inhibitory circuits is crucial for cortical functionality and defects during the development of γ-aminobutyric acid–expressing cortical interneurons contribute to the pathophysiology of psychiatric disorders. A critical developmental step is the migration of cortical interneurons from their site of origin within the subpallium to the cerebral cortex, orchestrated by intrinsic and extrinsic signals. In addition to genetic networks, epigenetic mechanisms such as DNA methylation by DNA methyltransferases (DNMTs) are suggested to drive stage-specific gene expression underlying developmental processes. The mosaic structure of the interneuron generating domains producing a variety of interneurons for diverse destinations complicates research on regulatory instances of cortical interneuron migration. To this end, we performed single-cell transcriptome analysis revealing Dnmt1 expression in subsets of migrating interneurons. We found that DNMT1 preserves the migratory morphology in part through transcriptional control over Pak6 that promotes neurite complexity in postmigratory cells. In addition, we identified Ccdc184, a gene of unknown function, to be highly expressed in postmitotic interneurons. Single-cell mRNA sequencing revealed a positive correlation of Ccdc184 with cell adhesion–associated genes pointing to potential implications of CCDC184 in processes relying on cell-cell adhesion–like migration or morphological differentiation of interneurons that deserves further investigations.
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Affiliation(s)
- Daniel Pensold
- Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Geraldine Zimmer
- Institute of Human Genetics, University Hospital Jena, Jena, Germany
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55
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Wei S, Hua HR, Chen QQ, Zhang Y, Chen F, Li SQ, Li F, Li JL. Dynamic changes in DNA demethylation in the tree shrew ( Tupaia belangeri chinensis) brain during postnatal development and aging. Zool Res 2018; 38:96-102. [PMID: 28409505 PMCID: PMC5396032 DOI: 10.24272/j.issn.2095-8137.2017.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5-hydroxymethylcytosine (5hmC) ten-eleven translocation (TET) enzyme-mediated active DNA demethylation products were dynamically changed and involved in postnatal brain development and aging in tree shrews (Tupaia belangeri chinensis). The levels of 5hmC in multiple anatomic structures showed a gradual increase throughout postnatal development, whereas a significant decrease in 5hmC was found in several brain regions in aged tree shrews, including in the prefrontal cortex and hippocampus, but not the cerebellum. Active changes in Tet mRNA levels indicated that TET2 and TET3 predominantly contributed to the changes in 5hmC levels. Our findings provide new insight into the dynamic changes in 5hmC levels in tree shrew brains during postnatal development and aging processes.
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Affiliation(s)
- Shu Wei
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Hai-Rong Hua
- Department of Pathology and Pathophysiology, School of Basic Medical Science, Kunming Medical University, Kunming Yunnan 650500, China
| | - Qian-Quan Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Ying Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Fei Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China; School of Life Science, University of Science and Technology of China, Hefei Anhui 230027, China
| | - Shu-Qing Li
- Department of Pathology and Pathophysiology, School of Basic Medical Science, Kunming Medical University, Kunming Yunnan 650500, China.
| | - Fan Li
- Department of Pathology and Pathophysiology, School of Basic Medical Science, Kunming Medical University, Kunming Yunnan 650500, China.
| | - Jia-Li Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China; Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China.
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56
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Ji S, Ding X, Ji J, Wu H, Sun R, Li X, Zhang L, Tian Y. Cranial irradiation inhibits hippocampal neurogenesis via DNMT1 and DNMT3A. Oncol Lett 2018; 15:2899-2904. [PMID: 29435016 PMCID: PMC5778827 DOI: 10.3892/ol.2017.7643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 11/16/2017] [Indexed: 02/07/2023] Open
Abstract
Impairment of neurogenesis in the hippocampus following whole-brain irradiation is the most important mechanism of radiation-induced cognitive dysfunction. However, the underlying mechanism remains obscure, meaning an ideal therapeutic target has not been identified. Evidence indicates that DNA methylation in neurons regulates synaptic plasticity and neuronal network activity. In the present study, the expression of DNA methyltransferases (DNMTs) in the hippocampus was analyzed to investigate their potential function in radiation-induced neurogenesis impairment. Sprague-Dawley rats were used throughout the present study, apportioned to the following groups: Control, radiation only, zebularine (a DNMT inhibitor) only, and radiation and zebularine together. Immunofluorescence staining revealed that radiation inhibited cellular proliferation and dendritic growth within new neurons of the hippocampus. In addition, western blot analysis demonstrated lower expression levels of DNMT1 and DNMT3A protein following radiation treatment compared with that in the non-irradiated control. Furthermore, compared with the radiation-only group, the radiation and zebularine group had significantly lower cell proliferative abilities, dendritic growth, and DNMT1 and DNMT3A protein levels. The results of the present study indicated that DNMT1 and DNMT3A may be involved in the pathogenesis of whole-brain radiation-induced neurogenesis impairment.
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Affiliation(s)
- Shengjun Ji
- Cancer Center, Nanjing Medical University Affiliated Suzhou Hospital, Suzhou, Jiangsu 215001, P.R. China
| | - Xin Ding
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Jiang Ji
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Haohao Wu
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Rui Sun
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Xiaoyang Li
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Liyuan Zhang
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Ye Tian
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
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57
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Stricker SH, Götz M. DNA-Methylation: Master or Slave of Neural Fate Decisions? Front Neurosci 2018; 12:5. [PMID: 29449798 PMCID: PMC5799221 DOI: 10.3389/fnins.2018.00005] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/04/2018] [Indexed: 01/05/2023] Open
Abstract
The pristine formation of complex organs depends on sharp temporal and spatial control of gene expression. Therefore, epigenetic mechanisms have been frequently attributed a central role in controlling cell fate determination. A prime example for this is the first discovered and still most studied epigenetic mark, DNA methylation, and the development of the most complex mammalian organ, the brain. Recently, the field of epigenetics has advanced significantly: new DNA modifications were discovered, epigenomic profiling became widely accessible, and methods for targeted epigenomic manipulation have been developed. Thus, it is time to challenge established models of epigenetic gene regulation. Here, we review the current state of knowledge about DNA modifications, their epigenomic distribution, and their regulatory role. We will summarize the evidence suggesting they possess crucial roles in neurogenesis and discuss whether this likely includes lineage choice regulation or rather effects on differentiation. Finally, we will attempt an outlook on how questions, which remain unresolved, could be answered soon.
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Affiliation(s)
- Stefan H Stricker
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universität, Munich, Germany.,Physiological Genomics, BioMedical Center, Munich, Germany.,German Research Center for Environmental Health, Ingolstädter Landstrasse 1, Germany and Biomedical Center, Institute of Stem Cell Research, Helmholtz Zentrum, Ludwig-Maximilian-Universität, Munich, Germany
| | - Magdalena Götz
- Physiological Genomics, BioMedical Center, Munich, Germany.,German Research Center for Environmental Health, Ingolstädter Landstrasse 1, Germany and Biomedical Center, Institute of Stem Cell Research, Helmholtz Zentrum, Ludwig-Maximilian-Universität, Munich, Germany.,German Excellence Cluster of Systems Neurology, Munich, Germany
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58
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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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59
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Abstract
The role of DNA methylation in brain development is an intense area of research because the brain has particularly high levels of CpG and mutations in many of the proteins involved in the establishment, maintenance, interpretation, and removal of DNA methylation impact brain development and/or function. These include DNA methyltransferase (DNMT), Ten-Eleven Translocation (TET), and Methyl-CpG binding proteins (MBPs). Recent advances in sequencing breadth and depth as well the detection of different forms of methylation have greatly expanded our understanding of the diversity of DNA methylation in the brain. The contributions of DNA methylation and associated proteins to embryonic and adult neurogenesis will be examined. Particular attention will be given to the impact on adult hippocampal neurogenesis (AHN), which is a key mechanism contributing to brain plasticity, learning, memory and mood regulation. DNA methylation influences multiple aspects of neurogenesis from stem cell maintenance and proliferation, fate specification, neuronal differentiation and maturation, and synaptogenesis. In addition, DNA methylation during neurogenesis has been shown to be responsive to many extrinsic signals, both under normal conditions and during disease and injury. Finally, crosstalk between DNA methylation, Methyl-DNA binding domain (MBD) proteins such as MeCP2 and MBD1 and histone modifying complexes is used as an example to illustrate the extensive interconnection between these epigenetic regulatory systems.
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Affiliation(s)
- Emily M Jobe
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Xinyu Zhao
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI, USA.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
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60
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DNA Methyltransferase 1 Is Indispensable for Development of the Hippocampal Dentate Gyrus. J Neurosci 2017; 36:6050-68. [PMID: 27251626 DOI: 10.1523/jneurosci.0512-16.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/17/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Development of the hippocampal dentate gyrus (DG) in the mammalian brain is achieved through multiple processes during late embryonic and postnatal stages, with each developmental step being strictly governed by extracellular cues and intracellular mechanisms. Here, we show that the maintenance DNA methyltransferase 1 (Dnmt1) is critical for development of the DG in the mouse. Deletion of Dnmt1 in neural stem cells (NSCs) at the beginning of DG development led to a smaller size of the granule cell layer in the DG. NSCs lacking Dnmt1 failed to establish proper radial processes or to migrate into the subgranular zone, resulting in aberrant neuronal production in the molecular layer of the DG and a reduction of integrated neurons in the granule cell layer. Interestingly, prenatal deletion of Dnmt1 in NSCs affected not only the developmental progression of the DG but also the properties of NSCs maintained into adulthood: Dnmt1-deficient NSCs displayed impaired neurogenic ability and proliferation. We also found that Dnmt1 deficiency in NSCs decreased the expression of Reelin signaling components in the developing DG and increased that of the cell cycle inhibitors p21 and p57 in the adult DG. Together, these findings led us to propose that Dnmt1 functions as a key regulator to ensure the proper development of the DG, as well as the proper status of NSCs maintained into adulthood, by modulating extracellular signaling and intracellular mechanisms. SIGNIFICANCE STATEMENT Here, we provide evidence that Dnmt1 is required for the proper development of the hippocampal dentate gyrus (DG). Deletion of Dnmt1 in neural stem cells (NSCs) at an early stage of DG development impaired the ability of NSCs to establish secondary radial glial scaffolds and to migrate into the subgranular zone of the DG, leading to aberrant neuronal production in the molecular layer, increased cell death, and decreased granule neuron production. Prenatal deletion of Dnmt1 in NSCs also induced defects in the proliferation and neurogenic ability of adult NSCs. Furthermore, we found that Dnmt1 regulates the expression of key extracellular signaling components during developmental stages while modulating intracellular mechanisms for proliferation and neuronal production of NSCs in the adult.
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61
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Groh S, Schotta G. Silencing of endogenous retroviruses by heterochromatin. Cell Mol Life Sci 2017; 74:2055-2065. [PMID: 28160052 PMCID: PMC11107624 DOI: 10.1007/s00018-017-2454-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/14/2016] [Accepted: 01/03/2017] [Indexed: 02/05/2023]
Abstract
Endogenous retroviruses (ERV) are an abundant class of repetitive elements in mammalian genomes. To ensure genomic stability, ERVs are largely transcriptionally silent. However, these elements also feature physiological roles in distinct developmental contexts, under which silencing needs to be partially relieved. ERV silencing is mediated through a heterochromatic structure, which is established by histone modification and DNA methylation machineries. This heterochromatic structure is largely refractory to transcriptional stimulation, however, challenges to the heterochromatic state, such as DNA replication, require re-establishment of the heterochromatic state in competition with transcriptional activators. In this review, we discuss the major pathways leading to efficient establishment of robust and inaccessible heterochromatin across ERVs.
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Affiliation(s)
- Sophia Groh
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152, Planegg-Martinsried, Germany
| | - Gunnar Schotta
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152, Planegg-Martinsried, Germany.
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62
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The Crucial Role of DNA Methylation and MeCP2 in Neuronal Function. Genes (Basel) 2017; 8:genes8050141. [PMID: 28505093 PMCID: PMC5448015 DOI: 10.3390/genes8050141] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/25/2017] [Accepted: 05/05/2017] [Indexed: 12/16/2022] Open
Abstract
A neuron is unique in its ability to dynamically modify its transcriptional output in response to synaptic activity while maintaining a core gene expression program that preserves cellular identity throughout a lifetime that is longer than almost every other cell type in the body. A contributing factor to the immense adaptability of a neuron is its unique epigenetic landscape that elicits locus-specific alterations in chromatin architecture, which in turn influences gene expression. One such epigenetic modification that is sensitive to changes in synaptic activity, as well as essential for maintaining cellular identity, is DNA methylation. The focus of this article is on the importance of DNA methylation in neuronal function, summarizing recent studies on critical players in the establishment of (the “writing”), the modification or erasure of (the “editing”), and the mediation of (the “reading”) DNA methylation in neurodevelopment and neuroplasticity. One “reader” of DNA methylation in particular, methyl-CpG-binding protein 2 (MeCP2), is highlighted, given its undisputed importance in neuronal function.
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63
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Weber-Stadlbauer U. Epigenetic and transgenerational mechanisms in infection-mediated neurodevelopmental disorders. Transl Psychiatry 2017; 7:e1113. [PMID: 28463237 PMCID: PMC5534947 DOI: 10.1038/tp.2017.78] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/07/2017] [Accepted: 02/23/2017] [Indexed: 02/07/2023] Open
Abstract
Prenatal infection is an environmental risk factor for various brain disorders with neurodevelopmental components, including autism spectrum disorder and schizophrenia. Modeling this association in animals shows that maternal immune activation negatively affects fetal brain development and leads to the emergence of behavioral disturbances later in life. Recent discoveries in these preclinical models suggest that epigenetic modifications may be a critical molecular mechanism by which prenatal immune activation can mediate changes in brain development and functions, even across generations. This review discusses the potential epigenetic mechanisms underlying the effects of prenatal infections, thereby highlighting how infection-mediated epigenetic reprogramming may contribute to the transgenerational transmission of pathological traits. The identification of epigenetic and transgenerational mechanisms in infection-mediated neurodevelopmental disorders appears relevant to brain disorders independently of existing diagnostic classifications and may help identifying complex patterns of transgenerational disease transmission beyond genetic inheritance. The consideration of ancestral infectious histories may be of great clinical interest and may be pivotal for developing new preventive treatment strategies against infection-mediated neurodevelopmental disorders.
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Affiliation(s)
- U Weber-Stadlbauer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
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64
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Podobinska M, Szablowska-Gadomska I, Augustyniak J, Sandvig I, Sandvig A, Buzanska L. Epigenetic Modulation of Stem Cells in Neurodevelopment: The Role of Methylation and Acetylation. Front Cell Neurosci 2017; 11:23. [PMID: 28223921 PMCID: PMC5293809 DOI: 10.3389/fncel.2017.00023] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/23/2017] [Indexed: 12/11/2022] Open
Abstract
The coordinated development of the nervous system requires fidelity in the expression of specific genes determining the different neural cell phenotypes. Stem cell fate decisions during neurodevelopment are strictly correlated with their epigenetic status. The epigenetic regulatory processes, such as DNA methylation and histone modifications discussed in this review article, may impact both neural stem cell (NSC) self-renewal and differentiation and thus play an important role in neurodevelopment. At the same time, stem cell decisions regarding fate commitment and differentiation are highly dependent on the temporospatial expression of specific genes contingent on the developmental stage of the nervous system. An interplay between the above, as well as basic cell processes, such as transcription regulation, DNA replication, cell cycle regulation and DNA repair therefore determine the accuracy and function of neuronal connections. This may significantly impact embryonic health and development as well as cognitive processes such as neuroplasticity and memory formation later in the adult.
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Affiliation(s)
- Martyna Podobinska
- Stem Cell Bioengineering Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences Warsaw, Poland
| | | | - Justyna Augustyniak
- Stem Cell Bioengineering Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences Warsaw, Poland
| | - Ioanna Sandvig
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU) Trondheim, Norway
| | - Axel Sandvig
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU) Trondheim, Norway
| | - Leonora Buzanska
- Stem Cell Bioengineering Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences Warsaw, Poland
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65
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Moyon S, Casaccia P. DNA methylation in oligodendroglial cells during developmental myelination and in disease. NEUROGENESIS 2017; 4:e1270381. [PMID: 28203606 DOI: 10.1080/23262133.2016.1270381] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/23/2016] [Accepted: 12/01/2016] [Indexed: 10/20/2022]
Abstract
Oligodendrocyte progenitor cells (OPC) are the myelinating cells of the central nervous system (CNS). During development, they differentiate into mature oligodendrocytes (OL) and ensheath axons, providing trophic and functional support to the neurons. This process is regulated by the dynamic expression of specific transcription factors, which, in turn, is controlled by epigenetic marks such as DNA methylation. Here we discuss recent findings showing that DNA methylation levels are differentially regulated in the oligodendrocyte lineage during developmental myelination, affecting both genes expression and alternative splicing events. Based on the phenotypic characterization of mice with genetic ablation of DNA methyltransferase 1 (Dnmt1) we conclude that DNA methylation is critical for efficient OPC expansion and for developmental myelination. Previous work suggests that in the context of diseases such as multiple sclerosis (MS) or gliomas, DNA methylation is differentially regulated in the CNS of affected individuals compared with healthy controls. In this commentary, based on the results of previous work, we propose the potential role of DNA methylation in adult oligodendroglial lineage cells in physiologic and pathological conditions, and delineate potential research approaches to be undertaken to test this hypothesis. A better understanding of this epigenetic modification in adult oligodendrocyte progenitor cells is essential, as it can potentially result in the design of new therapeutic strategies to enhance remyelination in MS patients or reduce proliferation in glioma patients.
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Affiliation(s)
- Sarah Moyon
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, NY, USA
| | - Patrizia Casaccia
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Neuroscience Initiative Advanced Science Research Center, CUNY, New York, NY, USA
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Hoang TV, Horowitz ER, Chaffee BR, Qi P, Flake RE, Bruney DG, Rasor BJ, Rosalez SE, Wagner BD, Robinson ML. Lens development requires DNMT1 but takes place normally in the absence of both DNMT3A and DNMT3B activity. Epigenetics 2017; 12:27-40. [PMID: 27824296 PMCID: PMC5270636 DOI: 10.1080/15592294.2016.1253651] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/14/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022] Open
Abstract
Despite the wealth of knowledge of transcription factors involved in lens development, little information exists about the role of DNA methylation in this process. Here, we investigated the role of DNA methylation in lens development and fiber cell differentiation using mice conditionally lacking maintenance or de novo methyltransferases in the lens lineage. We found that while Dnmt1 inactivation at the lens placode stage (via the Le-Cre transgene) led to lens DNA hypomethylation and severe lens epithelial apoptosis, lens fiber cell differentiation remained largely unaffected. The simultaneous deletion of phosphatase and tensin homolog (Pten) elevated the level of phosphorylated AKT and rescued many of the morphological defects and cell death in DNMT1-deficient lenses. With a different Cre driver (MLR10) we demonstrated that a small number of lens epithelial cells escaped Dnmt1-deletion and over-proliferated to compensate for the loss of Dnmt1-deleted cells, suggesting that lens epithelium possess a substantial capacity for self-renewal. Unlike lenses deficient for Dnmt1, inactivation of both Dnmt3a and Dnmt3b by either the Le-Cre or MLR10-Cre transgene did not result in any obvious lens phenotype prior to 10 months of age. Taken together, while lens epithelial cell survival requires DNMT1, morphologically normal lenses develop in the absence of both DNMT3A and DNMT3B.
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Affiliation(s)
- Thanh V. Hoang
- Department of Biology, Miami University, Oxford, OH, USA
| | | | | | - Peipei Qi
- Department of Biology, Miami University, Oxford, OH, USA
| | | | | | - Blake J. Rasor
- Department of Biology, Miami University, Oxford, OH, USA
| | | | - Brad D. Wagner
- Department of Biology, Miami University, Oxford, OH, USA
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Abstract
The limited regenerative capacity of neuronal cells requires tight orchestration of cell death and survival regulation in the context of longevity, age-associated diseases as well as during the development of the nervous system. Subordinate to genetic networks epigenetic mechanisms like DNA methylation and histone modifications are involved in the regulation of neuronal development, function and aging. DNA methylation by DNA methyltransferases (DNMTs), mostly correlated with gene silencing, is a dynamic and reversible process. In addition to their canonical actions performing cytosine methylation, DNMTs influence gene expression by interactions with histone modifying enzymes or complexes increasing the complexity of epigenetic transcriptional networks. DNMTs are expressed in neuronal progenitors, post-mitotic as well as adult neurons. In this review, we discuss the role and mode of actions of DNMTs including downstream networks in the regulation of neuronal survival in the developing and aging nervous system and its relevance for associated disorders.
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Affiliation(s)
- Judit Symmank
- Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Geraldine Zimmer
- Institute of Human Genetics, University Hospital Jena, Jena, Germany
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Benetatos L, Vartholomatos G. On the potential role of DNMT1 in acute myeloid leukemia and myelodysplastic syndromes: not another mutated epigenetic driver. Ann Hematol 2016; 95:1571-82. [PMID: 26983918 DOI: 10.1007/s00277-016-2636-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 03/04/2016] [Indexed: 12/19/2022]
Abstract
DNA methylation is the most common epigenetic modification in the mammalian genome. DNA methylation is governed by the DNA methyltransferases mainly DNMT1, DNMT3A, and DNMT3B. DNMT1 methylates hemimethylated DNA ensuring accurate DNA methylation maintenance. DNMT1 is involved in the proper differentiation of hematopoietic stem cells (HSCs) through the interaction with effector molecules. DNMT1 is deregulated in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) as early as the leukemic stem cell stage. Through the interaction with fundamental transcription factors, non-coding RNAs, fusion oncogenes and by modulating core members of signaling pathways, it can affect leukemic cells biology. DNMT1 action might be also catalytic-independent highlighting a methylation-independent mode of action. In this review, we have gathered some current facts of DNMT1 role in AML and MDS and we also propose some perspectives for future studies.
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Ramesh V, Bayam E, Cernilogar FM, Bonapace IM, Schulze M, Riemenschneider MJ, Schotta G, Götz M. Loss of Uhrf1 in neural stem cells leads to activation of retroviral elements and delayed neurodegeneration. Genes Dev 2016; 30:2199-2212. [PMID: 27798843 PMCID: PMC5088568 DOI: 10.1101/gad.284992.116] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/20/2016] [Indexed: 11/24/2022]
Abstract
In order to understand whether early epigenetic mechanisms instruct the long-term behavior of neural stem cells (NSCs) and their progeny, we examined Uhrf1 (ubiquitin-like PHD ring finger-1; also known as Np95), as it is highly expressed in NSCs of the developing brain and rapidly down-regulated upon differentiation. Conditional deletion of Uhrf1 in the developing cerebral cortex resulted in rather normal proliferation and neurogenesis but severe postnatal neurodegeneration. During development, deletion of Uhrf1 lead to global DNA hypomethylation with a strong activation of the intracisternal A particle (IAP) family of endogenous retroviral elements, accompanied by an increase in 5-hydroxymethylcytosine. Down-regulation of Tet enzymes rescued the IAP activation in Uhrf1 conditional knockout (cKO) cells, suggesting an antagonistic interplay between Uhrf1 and Tet on IAP regulation. As IAP up-regulation persists into postnatal stages in the Uhrf1 cKO mice, our data show the lack of means to repress IAPs in differentiating neurons that normally never express Uhrf1 The high load of viral proteins and other transcriptional deregulation ultimately led to postnatal neurodegeneration. Taken together, these data show that early developmental NSC factors can have long-term effects in neuronal differentiation and survival. Moreover, they highlight how specific the consequences of widespread changes in DNA methylation are for certain classes of retroviral elements.
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Affiliation(s)
- Vidya Ramesh
- Institute for Stem Cell Research, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Physiological Genomics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Efil Bayam
- Institute for Stem Cell Research, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Physiological Genomics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Filippo M Cernilogar
- Department of Molecular Biology, Biomedical Center, Ludwig-Maximilians-University, 82152 Munich, Germany
| | - Ian M Bonapace
- Department of Functional and Structural Biology, University of Insubria, 21052 Busto Arsizio, Italy
| | - Markus Schulze
- Department of Neuropathology, Regensburg University Hospital, 93053 Regensburg, Germany
| | | | - Gunnar Schotta
- Department of Molecular Biology, Biomedical Center, Ludwig-Maximilians-University, 82152 Munich, Germany
- Munich Center for Integrated Protein Science (CiPS), 81377 Munich, Germany
| | - Magdalena Götz
- Institute for Stem Cell Research, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Physiological Genomics, Helmholtz Center Munich, 85764 Neuherberg, Germany
- SyNergy, Excellence Cluster Systems Neurology, University of Munich, 81377 Munich, Germany
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70
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Noguchi H, Kimura A, Murao N, Namihira M, Nakashima K. Prenatal deletion of DNA methyltransferase 1 in neural stem cells impairs neurogenesis and causes anxiety-like behavior in adulthood. NEUROGENESIS 2016; 3:e1232679. [PMID: 27844025 DOI: 10.1080/23262133.2016.1232679] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 08/30/2016] [Accepted: 08/31/2016] [Indexed: 12/25/2022]
Abstract
Despite recent advances in our understanding of epigenetic regulation of central nervous system development, little is known regarding the effects of epigenetic dysregulation on neurogenesis and brain function in adulthood. In the present study, we show that prenatal deletion of DNA methyltransferase 1 (Dnmt1) in neural stem cells results in impaired neurogenesis as well as increases in inflammatory features (e.g., elevated glial fibrillary acidic protein [GFAP] expression in astrocytes and increased numbers of microglia) in the adult mouse brain. Moreover, these mice exhibited anxiety-like behavior during an open-field test. These findings suggest that Dnmt1 plays a critical role in regulating neurogenesis and behavior in the developing brain and into adulthood.
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Affiliation(s)
- Hirofumi Noguchi
- Stem Cell Biology and Medicine, Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University , Fukuoka, Japan
| | - Ayaka Kimura
- Stem Cell Biology and Medicine, Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University , Fukuoka, Japan
| | - Naoya Murao
- Stem Cell Biology and Medicine, Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University , Fukuoka, Japan
| | - Masakazu Namihira
- Molecular Neurophysiology Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology , Ibaraki, Japan
| | - Kinichi Nakashima
- Stem Cell Biology and Medicine, Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University , Fukuoka, Japan
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Subbanna S, Nagre NN, Shivakumar M, Basavarajappa BS. A single day of 5-azacytidine exposure during development induces neurodegeneration in neonatal mice and neurobehavioral deficits in adult mice. Physiol Behav 2016; 167:16-27. [PMID: 27594097 DOI: 10.1016/j.physbeh.2016.08.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/30/2016] [Accepted: 08/31/2016] [Indexed: 12/13/2022]
Abstract
The present study was undertaken to evaluate the immediate and long-term effects of a single-day exposure to 5-Azacytidine (5-AzaC), a DNA methyltransferase inhibitor, on neurobehavioral abnormalities in mice. Our findings suggest that the 5-AzaC treatment significantly inhibited DNA methylation, impaired extracellular signal-regulated kinase (ERK1/2) activation and reduced expression of the activity-regulated cytoskeleton-associated protein (Arc). These events lead to the activation of caspase-3 (a marker for neurodegeneration) in several brain regions, including the hippocampus and cortex, two brain areas that are essential for memory formation and memory storage, respectively. 5-AzaC treatment of P7 mice induced significant deficits in spatial memory, social recognition, and object memory in adult mice and deficits in long-term potentiation (LTP) in adult hippocampal slices. Together, these data demonstrate that the inhibition of DNA methylation by 5-AzaC treatment in P7 mice causes neurodegeneration and impairs ERK1/2 activation and Arc protein expression in neonatal mice and induces behavioral abnormalities in adult mice. DNA methylation-mediated mechanisms appear to be necessary for the proper maturation of synaptic circuits during development, and disruption of this process by 5-AzaC could lead to abnormal cognitive function.
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Affiliation(s)
- Shivakumar Subbanna
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Nagaraja N Nagre
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Madhu Shivakumar
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Balapal S Basavarajappa
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Department of Psychiatry, College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA.
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Yang A, Zhang H, Sun Y, Wang Y, Yang X, Yang X, Zhang H, Guo W, Zhu G, Tian J, Jia Y, Jiang Y. Modulation of FABP4 hypomethylation by DNMT1 and its inverse interaction with miR-148a/152 in the placenta of preeclamptic rats and HTR-8 cells. Placenta 2016; 46:49-62. [PMID: 27697222 DOI: 10.1016/j.placenta.2016.08.086] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 08/01/2016] [Accepted: 08/23/2016] [Indexed: 12/25/2022]
Abstract
Inflammation and dysregulated lipid metabolism are involved in the pathogenesis of preeclampsia, and fatty acid binding protein 4 (FABP4) is known to regulate both inflammation and lipid metabolism. In the present study, we elucidated the role of FABP4 using in vitro and in vivo models of preclampsia. We found increased expression of FABP4 in the placenta of preeclamptic rats, which was further confirmed in HTR-8 cells, an extravillous trophoblast cell line, treated with L-NAME. Overexpression of FABP4 in HTR-8 cells resulted in upregulated expression of pro-inflammatory cytokines IL-6 and TNF-α, and increased lipid accumulation, suggesting that FABP4 plays a role in preeclampsia. Furthermore, downregulation of methylation in the promotor resulted in increased FABP4 expression, which was mediated by downregulated DNA methyltransferase 1 (DNMT1). Bioinformatics analysis showed that miR-148a/152 regulated the expression of DNMT1, and additional in vitro studies revealed that miR-148a/152 inhibited DNMT1 expression by directly binding to its 3'-UTR. Interestingly, DNMT1 enhanced the expression of miR-148a/152 by downregulation of methylation in its promotor. Taken together, our results showed that FABP4 may be involved in the pathogenesis of preeclampsia, and the expression of FABP4 is enhanced by miR-148a/152 mediated inhibition of DNMT1 expression.
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Affiliation(s)
- Anning Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, China
| | - Huiping Zhang
- Prenatal Diagnosis Center of Ningxia Medical University General Hospital, Yinchuan, China; Ningxia Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Yinchuan, China
| | - Yue Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; State Key Laboratory of Biotherapy, Chengdu, China
| | - Yanhua Wang
- Prenatal Diagnosis Center of Ningxia Medical University General Hospital, Yinchuan, China
| | - Xiaoming Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; Ningxia Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Yinchuan, China
| | - Xiaoling Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; Ningxia Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Yinchuan, China
| | - Hui Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
| | - Wei Guo
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
| | - Guangrong Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
| | - Jue Tian
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; Ningxia Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Yinchuan, China
| | - Yuexia Jia
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; Ningxia Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Yinchuan, China
| | - Yideng Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China; Ningxia Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Yinchuan, China.
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Moyon S, Liang J, Casaccia P. Epigenetics in NG2 glia cells. Brain Res 2016; 1638:183-198. [PMID: 26092401 PMCID: PMC4683112 DOI: 10.1016/j.brainres.2015.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/11/2015] [Accepted: 06/02/2015] [Indexed: 12/16/2022]
Abstract
The interplay of transcription and epigenetic marks is essential for oligodendrocyte progenitor cell (OPC) proliferation and differentiation during development. Here, we review the recent advances in this field and highlight mechanisms of transcriptional repression and activation involved in OPC proliferation, differentiation and plasticity. We also describe how dysregulation of these epigenetic events may affect demyelinating disorders, and consider potential ways to manipulate NG2 cell behavior through modulation of the epigenome. This article is part of a Special Issue entitled SI:NG2-glia(Invited only).
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Affiliation(s)
- Sarah Moyon
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jialiang Liang
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Patrizia Casaccia
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Moyon S, Huynh JL, Dutta D, Zhang F, Ma D, Yoo S, Lawrence R, Wegner M, John GR, Emery B, Lubetzki C, Franklin RJM, Fan G, Zhu J, Dupree JL, Casaccia P. Functional Characterization of DNA Methylation in the Oligodendrocyte Lineage. Cell Rep 2016; 15:748-760. [PMID: 27149841 DOI: 10.1016/j.celrep.2016.03.060] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 02/08/2016] [Accepted: 03/15/2016] [Indexed: 01/08/2023] Open
Abstract
Oligodendrocytes derive from progenitors (OPCs) through the interplay of epigenomic and transcriptional events. By integrating high-resolution methylomics, RNA-sequencing, and multiple transgenic lines, this study defines the role of DNMT1 in developmental myelination. We detected hypermethylation of genes related to cell cycle and neurogenesis during differentiation of OPCs, yet genetic ablation of Dnmt1 resulted in inefficient OPC expansion and severe hypomyelination associated with ataxia and tremors in mice. This phenotype was not caused by lineage switch or massive apoptosis but was characterized by a profound defect of differentiation associated with changes in exon-skipping and intron-retention splicing events and by the activation of an endoplasmic reticulum stress response. Therefore, loss of Dnmt1 in OPCs is not sufficient to induce a lineage switch but acts as an important determinant of the coordination between RNA splicing and protein synthesis necessary for myelin formation.
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Affiliation(s)
- Sarah Moyon
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jimmy L Huynh
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Dipankar Dutta
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Fan Zhang
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Dan Ma
- Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AH, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AH, UK
| | - Seungyeul Yoo
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rebecca Lawrence
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael Wegner
- Institut für Biochemie, Universität Erlangen-Nürnberg, Fahrstrasse 17, 91054 Erlangen, Germany
| | - Gareth R John
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ben Emery
- Jungers Center for Neurosciences Research and Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Catherine Lubetzki
- Sorbonne Universités UPMC Université, Paris 06, UMR_S 1127, ICM-GHU Pitié-Salpêtrière, 75013 Paris, France
| | - Robin J M Franklin
- Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AH, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AH, UK
| | - Guoping Fan
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jun Zhu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Patrizia Casaccia
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Chaudhury S, Sharma V, Kumar V, Nag TC, Wadhwa S. Activity-dependent synaptic plasticity modulates the critical phase of brain development. Brain Dev 2016; 38:355-63. [PMID: 26515724 DOI: 10.1016/j.braindev.2015.10.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/21/2015] [Accepted: 10/10/2015] [Indexed: 12/28/2022]
Abstract
Plasticity or neuronal plasticity is a unique and adaptive feature of nervous system which allows neurons to reorganize their interactions in response to an intrinsic or extrinsic stimulation and shapes the formation and maintenance of a functional neuronal circuit. Synaptic plasticity is the most important form of neural plasticity and plays critical role during the development allowing the formation of precise neural connectivity via the process of pruning. In the sensory systems-auditory and visual, this process is heavily dependent on the external cues perceived during the development. Environmental enrichment paradigms in an activity-dependent manner result in early maturation of the synapses and more efficient trans-synaptic signaling or communication flow. This has been extensively observed in the avian auditory system. On the other hand, stimuli results in negative effect can cause alterations in the synaptic connectivity and strength resulting in various developmental brain disorders including autism, fragile X syndrome and rett syndrome. In this review we discuss the role of different forms of activity (spontaneous or environmental) during the development of the nervous system in modifying synaptic plasticity necessary for shaping the adult brain. Also, we try to explore various factors (molecular, genetic and epigenetic) involved in altering the synaptic plasticity in positive and negative way.
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Affiliation(s)
- Sraboni Chaudhury
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Vikram Sharma
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Vivek Kumar
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Tapas C Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Shashi Wadhwa
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India
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Konar A, Singh P, Thakur MK. Age-associated Cognitive Decline: Insights into Molecular Switches and Recovery Avenues. Aging Dis 2016; 7:121-9. [PMID: 27114845 PMCID: PMC4809604 DOI: 10.14336/ad.2015.1004] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/04/2015] [Indexed: 12/21/2022] Open
Abstract
Age-associated cognitive decline is an inevitable phenomenon that predisposes individuals for neurological and psychiatric disorders eventually affecting the quality of life. Scientists have endeavored to identify the key molecular switches that drive cognitive decline with advancing age. These newly identified molecules are then targeted as recovery of cognitive aging and related disorders. Cognitive decline during aging is multi-factorial and amongst several factors influencing this trajectory, gene expression changes are pivotal. Identifying these genes would elucidate the neurobiological underpinnings as well as offer clues that make certain individuals resilient to withstand the inevitable age-related deteriorations. Our laboratory has focused on this aspect and investigated a wide spectrum of genes involved in crucial brain functions that attribute to senescence induced cognitive deficits. We have recently identified master switches in the epigenome regulating gene expression alteration during brain aging. Interestingly, these factors when manipulated by chemical or genetic strategies successfully reverse the age-related cognitive impairments. In the present article, we review findings from our laboratory and others combined with supporting literary evidences on molecular switches of brain aging and their potential as recovery targets.
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Affiliation(s)
- Arpita Konar
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India; CSIR-Institute of Genomics and Integrative Biology, New Delhi 110025, India
| | - Padmanabh Singh
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India
| | - Mahendra K Thakur
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India
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Keil KP, Lein PJ. DNA methylation: a mechanism linking environmental chemical exposures to risk of autism spectrum disorders? ENVIRONMENTAL EPIGENETICS 2016; 2:dvv012. [PMID: 27158529 PMCID: PMC4856164 DOI: 10.1093/eep/dvv012] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
There is now compelling evidence that gene by environment interactions are important in the etiology of autism spectrum disorders (ASDs). However, the mechanisms by which environmental factors interact with genetic susceptibilities to confer individual risk for ASD remain a significant knowledge gap in the field. The epigenome, and in particular DNA methylation, is a critical gene expression regulatory mechanism in normal and pathogenic brain development. DNA methylation can be influenced by environmental factors such as diet, hormones, stress, drugs, or exposure to environmental chemicals, suggesting that environmental factors may contribute to adverse neurodevelopmental outcomes of relevance to ASD via effects on DNA methylation in the developing brain. In this review, we describe epidemiological and experimental evidence implicating altered DNA methylation as a potential mechanism by which environmental chemicals confer risk for ASD, using polychlorinated biphenyls (PCBs), lead, and bisphenol A (BPA) as examples. Understanding how environmental chemical exposures influence DNA methylation and how these epigenetic changes modulate the risk and/or severity of ASD will not only provide mechanistic insight regarding gene-environment interactions of relevance to ASD but may also suggest potential intervention strategies for these and potentially other neurodevelopmental disorders.
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Affiliation(s)
- Kimberly P. Keil
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Pamela J. Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
- *Correspondence address. Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Drive, Davis, CA 95616, USA. Tel:
(530) 752-1970
; Fax:
(530) 752-7690
; E-mail:
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Kim H, Jang WY, Kang MC, Jeong J, Choi M, Sung Y, Park S, Kwon W, Jang S, Kim MO, Kim SH, Ryoo ZY. TET1 contributes to neurogenesis onset time during fetal brain development in mice. Biochem Biophys Res Commun 2016; 471:437-43. [PMID: 26902115 DOI: 10.1016/j.bbrc.2016.02.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 02/15/2016] [Indexed: 11/16/2022]
Abstract
Epigenetic mechanisms are relevant to development and contribute to fetal neurogenesis. DNA methylation and demethylation contribute to neural gene expression during mouse brain development. Ten-eleven translocation 1 (TET1) regulates DNA demethylation by converting 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). TET1 specifically regulates 5hmC in the central nervous system (CNS), including during neurogenesis in the adult brain. However little is known about its function in fetal neurogenesis. In order to evaluate the role of TET1 in fetal brain development, we generated TET1-overexpressing transgenic (TG) mice. TET1 overexpression was confirmed in the brains of fetal mice, and we detected 5hmC overexpression in the TG brains compared to that in the wild type (WT) brains, using a dot-blot assay. In order to observe the role of TET1 in fetal brain development, we examined fetal brain samples at varied time points by using real-time PCR, Western blotting, and Immunofluorescence (IF). We confirmed that TET1 contributes to neurogenesis by upregulating the protein expressions of neuronal markers in the TG mouse brains, as determined by Western blotting. However the cortex structure or brain mass between WT and TG mice showed no significant difference by IF. In conclusion, TET1 makes the start time of neurogenesis earlier in the TG brains compared to that in the WT brains during fetal brain development.
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Affiliation(s)
- Hyerim Kim
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Woo Young Jang
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Min-Cheol Kang
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Jain Jeong
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Minjee Choi
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Yonghun Sung
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Song Park
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Wookbong Kwon
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Soyoung Jang
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Myoung Ok Kim
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Sung Hyun Kim
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | - Zae Young Ryoo
- School of Life Science and Biotechnology, KNU Creative BioResearch Group (BK21 plus project), Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea.
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79
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Çöpoğlu ÜS, Igci M, Bozgeyik E, Kokaçya MH, İğci YZ, Dokuyucu R, Ari M, Savaş HA. DNA Methylation of BDNF Gene in Schizophrenia. Med Sci Monit 2016; 22:397-402. [PMID: 26851233 PMCID: PMC4749043 DOI: 10.12659/msm.895896] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background Although genetic factors are risk factors for schizophrenia, some environmental factors are thought to be required for the manifestation of disease. Epigenetic mechanisms regulate gene functions without causing a change in the nucleotide sequence of DNA. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that regulates synaptic transmission and plasticity. It has been suggested that BDNF may play a role in the pathophysiology of schizophrenia. It is established that methylation status of the BDNF gene is associated with fear learning, memory, and stressful social interactions. In this study, we aimed to investigate the DNA methylation status of BDNF gene in patients with schizophrenia. Material/Methods The study included 49 patients (33 male and 16 female) with schizophrenia and 65 unrelated healthy controls (46 male and 19 female). Determination of methylation pattern of CpG islands was based on the principle that bisulfite treatment of DNA results in conversion of unmethylated cytosine residues into uracil, whereas methylated cytosine residues remain unmodified. Methylation-specific PCR was performed with primers specific for either methylated or unmethylated DNA. Results There was no significant difference in methylated or un-methylated status for BDNF promoters between schizophrenia patients and controls. The mean duration of illness was significantly lower in the hemi-methylated group compared to the non-methylated group for BDNF gene CpG island-1 in schizophrenia patients. Conclusions Although there were no differences in BDNF gene methylation status between schizophrenia patients and healthy controls, there was an association between duration of illness and DNA methylation.
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Affiliation(s)
- Ümit Sertan Çöpoğlu
- Department of Psychiatry, School of Medicine, Mustafa Kemal University, Hatay, Turkey
| | - Mehri Igci
- Department Medical Biology, School of Medicine, Gaziantep University, Gaziantep, Turkey
| | - Esra Bozgeyik
- Department Medical Biology, School of Medicine, Gaziantep University, Gaziantep, Turkey
| | - M Hanifi Kokaçya
- Department of Psychiatry, School of Medicine, Mustafa Kemal University, Hatay, Turkey
| | - Yusuf Ziya İğci
- Department Medical Biology, School of Medicine, Gaziantep University, Gaziantep, Turkey
| | - Recep Dokuyucu
- Department of Physiology, School of Medicine, Mustafa Kemal University, Hatay, Turkey
| | - Mustafa Ari
- Department of Physiology, Mustafa Kemal University, School of Medicine, Hatay, Turkey
| | - Haluk A Savaş
- Department Psychiatry, School of Medicine, Gaziantep University, Gaziantep, Turkey
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80
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ZHANG HUIPING, WANG YANHUA, CAO CHENGJIAN, YANG XIAOMING, MA SHENGCHAO, HAN XUEBO, YANG XIAOLING, YANG ANNING, TIAN JUE, XU HUA, ZHANG MINGHAO, JIANG YIDENG. A regulatory circuit involving miR-143 and DNMT3a mediates vascular smooth muscle cell proliferation induced by homocysteine. Mol Med Rep 2015; 13:483-90. [DOI: 10.3892/mmr.2015.4558] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 09/25/2015] [Indexed: 11/06/2022] Open
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81
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Keil KP, Vezina CM. DNA methylation as a dynamic regulator of development and disease processes: spotlight on the prostate. Epigenomics 2015; 7:413-25. [PMID: 26077429 DOI: 10.2217/epi.15.8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Prostate development, benign hyperplasia and cancer involve androgen and growth factor signaling as well as stromal-epithelial interactions. We review how DNA methylation influences these and related processes in other organ systems such as how proliferation is restricted to specific cell populations during defined temporal windows, how androgens elicit their actions and how cells establish, maintain and remodel DNA methylation in a time and cell specific fashion. We also discuss mechanisms by which hormones and endocrine disrupting chemicals reprogram DNA methylation in the prostate and elsewhere and examine evidence for a reawakening of developmental epigenetic pathways as drivers of prostate cancer and benign prostate hyperplasia.
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Affiliation(s)
- Kimberly P Keil
- Comparative Biosciences, University of Wisconsin-Madison, 1656 Linden Dr., Madison, WI 53705, USA
| | - Chad M Vezina
- Comparative Biosciences, University of Wisconsin-Madison, 1656 Linden Dr., Madison, WI 53705, USA
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82
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Hamidi T, Singh AK, Chen T. Genetic alterations of DNA methylation machinery in human diseases. Epigenomics 2015; 7:247-65. [PMID: 25942534 DOI: 10.2217/epi.14.80] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
DNA methylation plays a critical role in the regulation of chromatin structure and gene expression and is involved in a variety of biological processes. The levels and patterns of DNA methylation are regulated by both DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) and 'demethylating' proteins, including the ten-eleven translocation (TET) family of dioxygenases (TET1, TET2 and TET3). The effects of DNA methylation on chromatin and gene expression are largely mediated by methylated DNA 'reader' proteins, including MeCP2. Numerous mutations in DNMTs, TETs and MeCP2 have been identified in cancer and developmental disorders, highlighting the importance of the DNA methylation machinery in human development and physiology. In this review, we describe these mutations and discuss how they may lead to disease phenotypes.
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Affiliation(s)
- Tewfik Hamidi
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park - Research Division, 1808 Park Road 1C, P. O. Box 389, Smithville, TX 78957, USA
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83
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Lardenoije R, Iatrou A, Kenis G, Kompotis K, Steinbusch HWM, Mastroeni D, Coleman P, Lemere CA, Hof PR, van den Hove DLA, Rutten BPF. The epigenetics of aging and neurodegeneration. Prog Neurobiol 2015; 131:21-64. [PMID: 26072273 PMCID: PMC6477921 DOI: 10.1016/j.pneurobio.2015.05.002] [Citation(s) in RCA: 246] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 05/13/2015] [Accepted: 05/13/2015] [Indexed: 12/14/2022]
Abstract
Epigenetics is a quickly growing field encompassing mechanisms regulating gene expression that do not involve changes in the genotype. Epigenetics is of increasing relevance to neuroscience, with epigenetic mechanisms being implicated in brain development and neuronal differentiation, as well as in more dynamic processes related to cognition. Epigenetic regulation covers multiple levels of gene expression; from direct modifications of the DNA and histone tails, regulating the level of transcription, to interactions with messenger RNAs, regulating the level of translation. Importantly, epigenetic dysregulation currently garners much attention as a pivotal player in aging and age-related neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, where it may mediate interactions between genetic and environmental risk factors, or directly interact with disease-specific pathological factors. We review current knowledge about the major epigenetic mechanisms, including DNA methylation and DNA demethylation, chromatin remodeling and non-coding RNAs, as well as the involvement of these mechanisms in normal aging and in the pathophysiology of the most common neurodegenerative diseases. Additionally, we examine the current state of epigenetics-based therapeutic strategies for these diseases, which either aim to restore the epigenetic homeostasis or skew it to a favorable direction to counter disease pathology. Finally, methodological challenges of epigenetic investigations and future perspectives are discussed.
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Affiliation(s)
- Roy Lardenoije
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Artemis Iatrou
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Gunter Kenis
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Konstantinos Kompotis
- Center for Integrative Genomics, University of Lausanne, Genopode Building, 1015 Lausanne-Dorigny, Switzerland
| | - Harry W M Steinbusch
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Diego Mastroeni
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands; L.J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA
| | - Paul Coleman
- L.J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA
| | - Cynthia A Lemere
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Daniel L A van den Hove
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands; Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany
| | - Bart P F Rutten
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands.
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84
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Lister R, Mukamel EA. Turning over DNA methylation in the mind. Front Neurosci 2015; 9:252. [PMID: 26283895 PMCID: PMC4519686 DOI: 10.3389/fnins.2015.00252] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/06/2015] [Indexed: 01/22/2023] Open
Abstract
Cytosine DNA methylation is a stable epigenetic modification with established roles in regulating transcription, imprinting, female X-chromosome inactivation, and silencing of transposons. Dynamic gain or loss of DNA methylation reshapes the genomic landscape of cells during early differentiation, and in post-mitotic mammalian brain cells these changes continue to accumulate throughout the phases of cortical maturation in childhood and adolescence. There is also evidence for dynamic changes in the methylation status of specific genomic loci during the encoding of new memories, and these epigenome dynamics could play a causal role in memory formation. However, the mechanisms that may dynamically regulate DNA methylation in neurons during memory formation and expression, and the function of such epigenomic changes in this context, are unclear. Here we discuss the possible roles of DNA methylation in encoding and retrieval of memory.
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Affiliation(s)
- Ryan Lister
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia Perth, WA, Australia ; The Harry Perkins Institute of Medical Research Perth, WA, Australia
| | - Eran A Mukamel
- Department of Cognitive Science, University of California San Diego La Jolla, CA, USA
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85
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Morris MJ, Monteggia LM. Role of DNA methylation and the DNA methyltransferases in learning and memory. DIALOGUES IN CLINICAL NEUROSCIENCE 2015. [PMID: 25364286 PMCID: PMC4214178 DOI: 10.31887/dcns.2014.16.3/mmorris] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Dynamic regulation of chromatin structure in postmitotic neurons plays an important role in learning and memory. Methylation of cytosine nucleotides has historically been considered the strongest and least modifiable of epigenetic marks. Accumulating recent data suggest that rapid and dynamic methylation and demethylation of specific genes in the brain may play a fundamental role in learning, memory formation, and behavioral plasticity. The current review focuses on the emergence of data that support the role of DNA methylation and demethylation, and its molecular mediators in memory formation.
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Affiliation(s)
- Michael J Morris
- Department of Biological Sciences, University of Michigan-Dearborn, Dearborn, Michigan, USA
| | - Lisa M Monteggia
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA
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86
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Bose R, Spulber S, Kilian P, Heldring N, Lönnerberg P, Johnsson A, Conti M, Hermanson O, Ceccatelli S. Tet3 mediates stable glucocorticoid-induced alterations in DNA methylation and Dnmt3a/Dkk1 expression in neural progenitors. Cell Death Dis 2015; 6:e1793. [PMID: 26086966 PMCID: PMC4669838 DOI: 10.1038/cddis.2015.159] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/28/2015] [Accepted: 05/13/2015] [Indexed: 12/15/2022]
Abstract
Developmental exposure to excess glucocorticoids (GCs) has harmful neurodevelopmental effects, which include persistent alterations in the differentiation potential of embryonic neural stem cells (NSCs). The mechanisms, however, are largely unknown. Here, we investigated the effects of dexamethasone (Dex, a synthetic GC analog) by MeDIP-like genome-wide analysis of differentially methylated DNA regions (DMRs) in NSCs isolated from embryonic rat cortices. We found that Dex-induced genome-wide DNA hypomethylation in the NSCs in vitro. Similarly, in utero exposure to Dex resulted in global DNA hypomethylation in the cerebral cortex of 3-day-old mouse pups. Dex-exposed NSCs displayed stable changes in the expression of the DNA methyltransferase Dnmt3a, and Dkk1, an essential factor for neuronal differentiation. These alterations were dependent on Tet3 upregulation. In conclusion, we propose that GCs elicit strong and persistent effects on DNA methylation in NSCs with Tet3 playing an essential role in the regulation of Dnmt3a and Dkk1. Noteworthy is the occurrence of similar changes in Dnmt3a and Dkk1 gene expression after exposure to excess GC in vivo.
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Affiliation(s)
- R Bose
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - S Spulber
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - P Kilian
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - N Heldring
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - P Lönnerberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - A Johnsson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - M Conti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - O Hermanson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - S Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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87
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Montalbán-Loro R, Domingo-Muelas A, Bizy A, Ferrón SR. Epigenetic regulation of stemness maintenance in the neurogenic niches. World J Stem Cells 2015; 7:700-710. [PMID: 26029342 PMCID: PMC4444611 DOI: 10.4252/wjsc.v7.i4.700] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/12/2014] [Accepted: 03/20/2015] [Indexed: 02/06/2023] Open
Abstract
In the adult mouse brain, the subventricular zone lining the lateral ventricles and the subgranular zone in the dentate gyrus of the hippocampus are two zones that contain neural stem cells (NSCs) with the capacity to give rise to neurons and glia during the entire life of the animal. Spatial and temporal regulation of gene expression in the NSCs population is established and maintained by the coordinated interaction between transcription factors and epigenetic regulators which control stem cell fate. Epigenetic mechanisms are heritable alterations in genome function that do not involve changes in DNA sequence itself but that modulate gene expression, acting as mediators between the environment and the genome. At the molecular level, those epigenetic mechanisms comprise chemical modifications of DNA such as methylation, hydroxymethylation and histone modifications needed for the maintenance of NSC identity. Genomic imprinting is another normal epigenetic process leading to parental-specific expression of a gene, known to be implicated in the control of gene dosage in the neurogenic niches. The generation of induced pluripotent stem cells from NSCs by expression of defined transcription factors, provide key insights into fundamental principles of stem cell biology. Epigenetic modifications can also occur during reprogramming of NSCs to pluripotency and a better understanding of this process will help to elucidate the mechanisms required for stem cell maintenance. This review takes advantage of recent studies from the epigenetic field to report knowledge regarding the mechanisms of stemness maintenance of neural stem cells in the neurogenic niches.
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88
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Shin J, Ming GL, Song H. DNA modifications in the mammalian brain. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0512. [PMID: 25135973 DOI: 10.1098/rstb.2013.0512] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
DNA methylation is a crucial epigenetic mark in mammalian development, genomic imprinting, X-inactivation, chromosomal stability and suppressing parasitic DNA elements. DNA methylation in neurons has also been suggested to play important roles for mammalian neuronal functions, and learning and memory. In this review, we first summarize recent discoveries and fundamental principles of DNA modifications in the general epigenetics field. We then describe the profiles of different DNA modifications in the mammalian brain genome. Finally, we discuss roles of DNA modifications in mammalian brain development and function.
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Affiliation(s)
- Jaehoon Shin
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guo-Li Ming
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hongjun Song
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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89
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Kaffman A. Early-life stress restricts the capacity of adult progenitor cells to differentiate into neurons. Biol Psychiatry 2015; 77:307-9. [PMID: 25592267 PMCID: PMC4435555 DOI: 10.1016/j.biopsych.2014.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Arie Kaffman
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut..
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90
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Noguchi H, Kimura A, Murao N, Matsuda T, Namihira M, Nakashima K. Expression of DNMT1 in neural stem/precursor cells is critical for survival of newly generated neurons in the adult hippocampus. Neurosci Res 2015; 95:1-11. [PMID: 25659757 DOI: 10.1016/j.neures.2015.01.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 01/17/2023]
Abstract
Adult neurogenesis persists throughout life in the dentate gyrus (DG) of the hippocampus, and its importance has been highlighted in hippocampus-dependent learning and memory. Adult neurogenesis consists of multiple processes: maintenance and neuronal differentiation of neural stem/precursor cells (NS/PCs), followed by survival and maturation of newborn neurons and their integration into existing neuronal circuitry. However, the mechanisms that govern these processes remain largely unclear. Here we show that DNA methyltransferase 1 (DNMT1), an enzyme responsible for the maintenance of DNA methylation, is highly expressed in proliferative cells in the adult DG and plays an important role in the survival of newly generated neurons. Deletion of Dnmt1 in adult NS/PCs (aNS/PCs) did not affect the proliferation and differentiation of aNS/PCs per se. However, it resulted in a decrease of newly generated mature neurons, probably due to gradual cell death after aNS/PCs differentiated into neurons in the hippocampus. Interestingly, loss of DNMT1 in post-mitotic neurons did not influence their survival. Taken together, these findings suggest that the presence of DNMT1 in aNS/PCs is crucial for the survival of newly generated neurons, but is dispensable once they accomplish neuronal differentiation in the adult hippocampus.
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Affiliation(s)
- Hirofumi Noguchi
- Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Laboratory of Gene Regulation Research, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, Japan
| | - Ayaka Kimura
- Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Naoya Murao
- Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Laboratory of Gene Regulation Research, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, Japan
| | - Taito Matsuda
- Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masakazu Namihira
- Molecular Neurophysiology Group, Biomedical Research Institute, AIST, Ibaraki, Japan
| | - Kinichi Nakashima
- Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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91
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Babenko O, Kovalchuk I, Metz GAS. Stress-induced perinatal and transgenerational epigenetic programming of brain development and mental health. Neurosci Biobehav Rev 2014; 48:70-91. [PMID: 25464029 DOI: 10.1016/j.neubiorev.2014.11.013] [Citation(s) in RCA: 324] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 09/19/2014] [Accepted: 11/17/2014] [Indexed: 12/20/2022]
Abstract
Research efforts during the past decades have provided intriguing evidence suggesting that stressful experiences during pregnancy exert long-term consequences on the future mental wellbeing of both the mother and her baby. Recent human epidemiological and animal studies indicate that stressful experiences in utero or during early life may increase the risk of neurological and psychiatric disorders, arguably via altered epigenetic regulation. Epigenetic mechanisms, such as miRNA expression, DNA methylation, and histone modifications are prone to changes in response to stressful experiences and hostile environmental factors. Altered epigenetic regulation may potentially influence fetal endocrine programming and brain development across several generations. Only recently, however, more attention has been paid to possible transgenerational effects of stress. In this review we discuss the evidence of transgenerational epigenetic inheritance of stress exposure in human studies and animal models. We highlight the complex interplay between prenatal stress exposure, associated changes in miRNA expression and DNA methylation in placenta and brain and possible links to greater risks of schizophrenia, attention deficit hyperactivity disorder, autism, anxiety- or depression-related disorders later in life. Based on existing evidence, we propose that prenatal stress, through the generation of epigenetic alterations, becomes one of the most powerful influences on mental health in later life. The consideration of ancestral and prenatal stress effects on lifetime health trajectories is critical for improving strategies that support healthy development and successful aging.
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Affiliation(s)
- Olena Babenko
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4; Department of Biological Sciences, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4
| | - Igor Kovalchuk
- Department of Biological Sciences, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4
| | - Gerlinde A S Metz
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4
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92
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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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93
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Morris MJ, Adachi M, Na ES, Monteggia LM. Selective role for DNMT3a in learning and memory. Neurobiol Learn Mem 2014; 115:30-7. [PMID: 24937014 PMCID: PMC4250315 DOI: 10.1016/j.nlm.2014.06.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 11/23/2022]
Abstract
Methylation of cytosine nucleotides is governed by DNA methyltransferases (DNMTs) that establish de novo DNA methylation patterns in early embryonic development (e.g., DNMT3a and DNMT3b) or maintain those patterns on hemimethylated DNA in dividing cells (e.g., DNMT1). DNMTs continue to be expressed at high levels in mature neurons, however their impact on neuronal function and behavior are unclear. To address this issue we examined DNMT1 and DNMT3a expression following associative learning. We also generated forebrain specific conditional Dnmt1 or Dnmt3a knockout mice and characterized them in learning and memory paradigms as well as for alterations in long-term potentiation (LTP) and synaptic plasticity. Here, we report that experience in an associative learning task impacts expression of Dnmt3a, but not Dnmt1, in brain areas that mediate learning of this task. We also found that Dnmt3a knockout mice, and not Dnmt1 knockouts have synaptic alterations as well as learning deficits on several associative and episodic memory tasks. These findings indicate that the de novo DNA methylating enzyme DNMT3a in postmitotic neurons is necessary for normal memory formation and its function cannot be substituted by the maintenance DNA methylating enzyme DNMT1.
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Affiliation(s)
- Michael J Morris
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, United States; Department of Natural Sciences, University of Michigan - Dearborn, Dearborn, MI 48128, United States
| | - Megumi Adachi
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, United States
| | - Elisa S Na
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, United States
| | - Lisa M Monteggia
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, United States.
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94
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Reduced recognition memory is correlated with decrease in DNA methyltransferase1 and increase in histone deacetylase2 protein expression in old male mice. Biogerontology 2014; 15:339-46. [PMID: 24924148 DOI: 10.1007/s10522-014-9504-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 04/28/2014] [Indexed: 01/26/2023]
Abstract
Chromatin modifying enzymes DNA methyltransferases (DNMTs), histone deacetylase (HDAC) 2 and CREB binding protein (CBP) play a crucial role in memory, particularly during consolidation process which declines with advancing age. However, the expression of these enzymes and their effect on memory consolidation during aging are not clearly understood. In the present study, novel object recognition test was used to assess the memory consolidation followed by expression analysis of DNMTs, HDAC2 and CBP in the cerebral cortex and hippocampus of young, adult and old male mice. Object recognition memory was reduced in old as compared to young and adult. DNMT1 protein expression was high in the cerebral cortex and hippocampus of young male mice, but declined gradually with age. On the other hand, HDAC2 mRNA and protein expression increased in the hippocampus of old male mice as compared to young and adult. Alteration in the expression of these enzymes is correlated with reduced recognition memory in old.
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95
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Wang F, Fischhaber PL, Guo C, Tang TS. Epigenetic modifications as novel therapeutic targets for Huntington’s disease. Epigenomics 2014; 6:287-97. [DOI: 10.2217/epi.14.19] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Huntington’s disease is a late-onset, autosomal dominant neurodegenerative disorder characterized by motor, cognitive and psychiatric symptomatology. The earliest stage of Huntington’s disease is marked by alterations in gene expression, which partially results from dysregulated epigenetic modifications. In past decades, altered epigenetic markers including histone modifications (acetylation, methylation, ubiquitylation and phosphorylation) and DNA modifications (cytosine methylation and hydroxymethylation) have been reported as important epigenetic features in patients and multiple animal models of Huntington’s disease. Drugs aimed to correct some of those alterations have shown promise in treating Huntington’s disease. This article discusses the field of epigenetics for potential Huntington’s disease interventions and presents the most recent findings in this area.
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Affiliation(s)
- Fengli Wang
- State Key Laboratory of Biomembrane & Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Paula L Fischhaber
- Department of Chemistry & Biochemistry, California State University Northridge, Northridge, CA 91330–8262, USA
| | - Caixia Guo
- Center for Genome Variations & Precision Biomedicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China
| | - Tie-Shan Tang
- State Key Laboratory of Biomembrane & Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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96
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Zhang G, Pradhan S. Mammalian epigenetic mechanisms. IUBMB Life 2014; 66:240-56. [PMID: 24706538 DOI: 10.1002/iub.1264] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/19/2014] [Indexed: 12/31/2022]
Abstract
The mammalian genome is packaged into chromatin that is further compacted into three-dimensional structures consisting of distinct functional domains. The higher order structure of chromatin is in part dictated by enzymatic DNA methylation and histone modifications to establish epigenetic layers controlling gene expression and cellular functions, without altering the underlying DNA sequences. Apart from DNA and histone modifications, non-coding RNAs can also regulate the dynamics of the mammalian gene expression and various physiological functions including cell division, differentiation, and apoptosis. Aberrant epigenetic signatures are associated with abnormal developmental processes and diseases such as cancer. In this review, we will discuss the different layers of epigenetic regulation, including writer enzymes for DNA methylation, histone modifications, non-coding RNA, and chromatin conformation. We will highlight the combinatorial role of these structural and chemical modifications along with their partners in various cellular processes in mammalian cells. We will also address the cis and trans interacting "reader" proteins that recognize these modifications and "eraser" enzymes that remove these marks. Furthermore, an attempt will be made to discuss the interplay between various epigenetic writers, readers, and erasures in the establishment of mammalian epigenetic mechanisms.
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97
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Sloan SA, Barres BA. Mechanisms of astrocyte development and their contributions to neurodevelopmental disorders. Curr Opin Neurobiol 2014; 27:75-81. [PMID: 24694749 DOI: 10.1016/j.conb.2014.03.005] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 03/06/2014] [Accepted: 03/10/2014] [Indexed: 10/25/2022]
Abstract
The development of functional neural circuits relies upon the coordination of various cell types. In particular, astrocytes play a crucial role in orchestrating neural development by powerfully coordinating synapse formation and function, neuronal survival, and axon guidance. While astrocytes help to shape neural circuits in the developing brain, the mechanisms underlying their own development may play an equally crucial role in nervous system function. The onset of astrogenesis is a temporally regulated phenomenon that relies upon exogenously secreted cues and intrinsic chromatin changes. Defects in the mechanisms underlying astrogenesis or in astrocyte function during early development may contribute to the progression of a variety of neurodevelopmental disorders.
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Affiliation(s)
- Steven A Sloan
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305-5125, United States.
| | - Ben A Barres
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305-5125, United States
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98
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Lin N, Qin S, Luo S, Cui S, Huang G, Zhang X. Homocysteine induces cytotoxicity and proliferation inhibition in neural stem cells via DNA methylation in vitro. FEBS J 2014; 281:2088-96. [PMID: 24612628 DOI: 10.1111/febs.12764] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 01/12/2014] [Accepted: 02/20/2014] [Indexed: 11/29/2022]
Abstract
Mild to moderate hyperhomocysteinemia has been implicated in neurodevelopmental disorders and neurodegenerative diseases in human studies. Although the molecular mechanisms underlying the effects of homocysteine (Hcy) neurotoxicity on the nervous system are not yet fully understood, inhibition of neural stem cell (NSC) proliferation and alterations in DNA methylation may be involved. The aim of the present study was to characterize the effects of Hcy on DNA methylation in NSCs, and to explore how Hcy-induced changes in DNA methylation patterns affect NSC proliferation. We found that D,L-Hcy (30-1000 μm) but not L-cysteine inhibited cell proliferation and reduced levels of global DNA methylation in NSCs from neonatal rat hippocampus and increased cell injury. High levels of Hcy also induced an increase in S-adenosylhomocysteine (SAH), a decrease in the ratio of S-adenosylmethionine (SAM) to SAH, and a reduction in protein expression of the DNA methyltransferases DNMT1, DNMT3a and DNMT3b and their enzymatic activity. Moreover, the DNMT inhibitor zebularine reduced the global DNA methylation level and inhibited NSC proliferation. Our results suggest that alterations in DNA methylation may be an important mechanism by which high levels of Hcy inhibit NSC viability in vitro. Hcy-induced DNA hypomethylation may be caused by a reduction in the DNMT activity which is regulated by the cellular concentrations of SAM and SAH, or their protein expression levels. Our results also suggest that Hcy may play a role in the pathogenesis of certain nervous system diseases via a molecular mechanism that involves negative regulation of NSC proliferation and alterations in DNA methylation.
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Affiliation(s)
- Ningning Lin
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, China
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99
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Abstract
In humans, genomic DNA is organized in 23 chromosome pairs coding for roughly 25,000 genes. Not all of them are active at all times. During development, a broad range of different cell types needs to be generated in a highly ordered and reproducible manner, requiring selective gene expression programs. Epigenetics can be regarded as the information management system that is able to index or bookmark distinct regions in our genome to regulate the readout of DNA. It further comprises the molecular memory of any given cell, allowing it to store information of previously experienced external (e.g., environmental) or internal (e.g., developmental) stimuli, to learn from this experience and to respond. The underlying epigenetic mechanisms can be synergistic, antagonistic, or mutually exclusive and their large variety combined with the variability and interdependence is thought to provide the molecular basis for any phenotypic variation in physiological and pathological conditions. Thus, widespread reconfiguration of the epigenome is not only a key feature of neurodevelopment, brain maturation, and adult brain function but also disease.
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Affiliation(s)
- Katja Kobow
- Department of Neuropathology, University Hospital Erlangen, Schwabachanlage, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Schwabachanlage, Erlangen, Germany.
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100
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Grissom N, Bowman N, Reyes TM. Epigenetic programming of reward function in offspring: a role for maternal diet. Mamm Genome 2013; 25:41-8. [PMID: 24317506 DOI: 10.1007/s00335-013-9487-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/22/2013] [Indexed: 12/15/2022]
Abstract
Early life development, through gestation and lactation, represents a timeframe of extreme vulnerability for the developing fetus in general, and for the central nervous system in particular. An adverse perinatal environment can have a lasting negative impact on brain development, increasing the risk for developmental disorders and broader psychopathologies. A major determinant of the fetal developmental environment is maternal diet. The present review summarizes the current literature regarding the effect of poor maternal perinatal nutrition on offspring brain development, with an emphasis on reward-related neural systems and behaviors. Epigenetic mechanisms represent a likely link between maternal diet and persistent changes in offspring brain development, and these mechanisms are presented and discussed within the context of perinatal maternal nutrition.
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Affiliation(s)
- Nicola Grissom
- Department of Pharmacology, Perelman School of Medicine, Institute for Translational Medicine and Therapeutics, University of Pennsylvania, 10-131 Smilow Center for Translational Research, Philadelphia, PA, 19104, USA
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