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Liu Z, Zhou T, Gao D. Genetic and epigenetic regulation of growth, reproduction, disease resistance and stress responses in aquaculture. Front Genet 2022; 13:994471. [PMID: 36406125 PMCID: PMC9666392 DOI: 10.3389/fgene.2022.994471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/20/2022] [Indexed: 11/25/2022] Open
Abstract
Major progress has been made with genomic and genetic studies in aquaculture in the last decade. However, research on epigenetic regulation of aquaculture traits is still at an early stage. It is apparent that most, if not all, aquaculture traits are regulated at both genetic and epigenetic levels. This paper reviews recent progress in understanding of genetic and epigenetic regulation of important aquaculture traits such as growth, reproduction, disease resistance, and stress responses. Although it is challenging to make generalized statements, DNA methylation is mostly correlated with down-regulation of gene expression, especially when at promoters and enhancers. As such, methylation of growth factors and their receptors is negatively correlated with growth; hypomethylation of genes important for stress tolerance is correlated with increased stress tolerance; hypomethylation of genes important for male or female sex differentiation leads to sex differentiation into males or females, respectively. It is apparent that environmental regulation of aquaculture traits is mediated at the level of epigenetic regulation, and such environment-induced epigenetic changes appeared to be intergenerationally inherited, but evidences for transgenerational inheritance are still limited.
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Affiliation(s)
- Zhanjiang Liu
- Department of Biology, College of Arts and Sciences, Syracuse University, Syracuse, NY, United States,*Correspondence: Zhanjiang Liu,
| | - Tao Zhou
- Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Dongya Gao
- Department of Biology, College of Arts and Sciences, Syracuse University, Syracuse, NY, United States
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2
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The Role of DNA Methylation in Stroke Recovery. Int J Mol Sci 2022; 23:ijms231810373. [PMID: 36142283 PMCID: PMC9499691 DOI: 10.3390/ijms231810373] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/17/2022] Open
Abstract
Epigenetic alterations affect the onset of ischemic stroke, brain injury after stroke, and mechanisms of poststroke recovery. In particular, DNA methylation can be dynamically altered by maintaining normal brain function or inducing abnormal brain damage. DNA methylation is regulated by DNA methyltransferase (DNMT), which promotes methylation, DNA demethylase, which removes methyl groups, and methyl-cytosine–phosphate–guanine-binding domain (MBD) protein, which binds methylated DNA and inhibits gene expression. Investigating the effects of modulating DNMT, TET, and MBD protein expression on neuronal cell death and neurorepair in ischemic stroke and elucidating the underlying mechanisms can facilitate the formulation of therapeutic strategies for neuroprotection and promotion of neuronal recovery after stroke. In this review, we summarize the role of DNA methylation in neuroprotection and neuronal recovery after stroke according to the current knowledge regarding the effects of DNA methylation on excitotoxicity, oxidative stress, apoptosis, neuroinflammation, and recovery after ischemic stroke. This review of the literature regarding the role of DNA methylation in neuroprotection and functional recovery after stroke may contribute to the development and application of novel therapeutic strategies for stroke.
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3
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Habano W, Miura T, Terashima J, Ozawa S. Aryl hydrocarbon receptor as a DNA methylation reader in the stress response pathway. Toxicology 2022; 470:153154. [PMID: 35301058 DOI: 10.1016/j.tox.2022.153154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/31/2022] [Accepted: 03/10/2022] [Indexed: 10/18/2022]
Abstract
The aryl hydrocarbon receptor (AhR) mediates various cellular responses upon exposure to exogenous and endogenous stress factors. In these responses, AhR plays a dual role as a stress sensor for detecting various AhR ligands and as a transcription factor that upregulates the expression of downstream effector genes, such as those encoding drug-metabolizing enzymes. As a transcription factor, it selectively binds to the unmethylated form of a specific sequence called the xenobiotic responsive element (XRE). We suggest that AhR is a novel DNA methylation reader, unlike classical methylation readers, such as methyl-CpG-binding protein 2, which binds to methylated sequences. Under physiological conditions of continuous exposure to endogenous AhR ligands, such as kynurenine, methylation states of the individual target XREs must be strictly regulated to select and coordinate the expression of downstream genes responsible for maintaining homeostasis in the body. In contrast, long-term exposure to AhR ligands frequently leads to changes in the methylation patterns around the XRE sequence. These data indicate that AhR may contribute to the adaptive cellular response to various stresses by modulating DNA methylation. Thus, the DNA methylation profile of AhR target genes should be dynamically controlled through a balance between robustness and flexibility under both physiological and stress conditions. AhR is a pivotal player in the regulation of stress response as it shows versatility by functioning as a stress sensor, methylation reader, and putative methylation modulator.
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Affiliation(s)
- Wataru Habano
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan.
| | - Toshitaka Miura
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan
| | - Jun Terashima
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan
| | - Shogo Ozawa
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan
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4
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Tajima S, Suetake I, Takeshita K, Nakagawa A, Kimura H, Song J. Domain Structure of the Dnmt1, Dnmt3a, and Dnmt3b DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:45-68. [PMID: 36350506 PMCID: PMC11025882 DOI: 10.1007/978-3-031-11454-0_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In mammals, three major DNA methyltransferases, Dnmt1, Dnmt3a, and Dnmt3b, have been identified. Dnmt3a and Dnmt3b are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. Dnmt3-like (Dnmt3l), which is a member of the Dnmt3 family but does not possess DNA methylation activity, was reported to be indispensable for global methylation in germ cells. Once the DNA methylation patterns are established, maintenance-type DNA methyltransferase Dnmt1 faithfully propagates them to the next generation via replication. All Dnmts possess multiple domains. For instance, Dnmt3a and Dnmt3b each contain a Pro-Trp-Trp-Pro (PWWP) domain that recognizes the histone H3K36me2/3 mark, an Atrx-Dnmt3-Dnmt3l (ADD) domain that recognizes unmodified histone H3 tail, and a catalytic domain that methylates CpG sites. Dnmt1 contains an N-terminal independently folded domain (NTD) that interacts with a variety of regulatory factors, a replication foci-targeting sequence (RFTS) domain that recognizes the histone H3K9me3 mark and H3 ubiquitylation, a CXXC domain that recognizes unmodified CpG DNA, two tandem Bromo-Adjacent-homology (BAH1 and BAH2) domains that read the H4K20me3 mark with BAH1, and a catalytic domain that preferentially methylates hemimethylated CpG sites. In this chapter, the structures and functions of these domains are described.
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Affiliation(s)
- Shoji Tajima
- Institute for Protein Research, Osaka University, Osaka, Japan.
| | - Isao Suetake
- Department of Nutritional Sciences, Faculty of Nutritional Sciences, Nakamura Gakuen University, Fukuoka, Japan
| | | | - Atsushi Nakagawa
- Laboratory of Supramolecular Crystallography, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Hironobu Kimura
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - Jikui Song
- Department of Biochemistry, University of California Riverside, Riverside, CA, USA.
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5
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Moon BS, Cai M, Lee G, Zhao T, Song X, Giannotta SL, Attenello FJ, Yu M, Lu W. Epigenetic modulator inhibition overcomes temozolomide chemoresistance and antagonizes tumor recurrence of glioblastoma. J Clin Invest 2021; 130:5782-5799. [PMID: 33016927 DOI: 10.1172/jci127916] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 07/16/2020] [Indexed: 12/17/2022] Open
Abstract
Glioblastoma multiforme (GBM) heterogeneity causes a greater number of deaths than any other brain tumor, despite the availability of alkylating chemotherapy. GBM stem-like cells (GSCs) contribute to GBM complexity and chemoresistance, but it remains challenging to identify and target GSCs or factors that control their activity. Here, we identified a specific GSC subset and show that activity of these cells is positively regulated by stabilization of methyl CpG binding domain 3 (MBD3) protein. MBD3 binds to CK1A and to BTRCP E3 ubiquitin ligase, triggering MBD3 degradation, suggesting that modulating this circuit could antagonize GBM recurrence. Accordingly, xenograft mice treated with the CK1A activator pyrvinium pamoate (Pyr-Pam) showed enhanced MBD3 degradation in cells expressing high levels of O6-methylguanine-DNA methyltransferase (MGMT) and in GSCs, overcoming temozolomide chemoresistance. Pyr-Pam blocked recruitment of MBD3 and the repressive nucleosome remodeling and deacetylase (NuRD) complex to neurogenesis-associated gene loci and increased acetyl-histone H3 activity and GSC differentiation. We conclude that CK1A/BTRCP/MBD3/NuRD signaling modulates GSC activation and malignancy, and that targeting this signaling could suppress GSC proliferation and GBM recurrence.
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Affiliation(s)
- Byoung-San Moon
- Department of Neurosurgery and.,Broad Center for Regenerative Medicine and Stem Cell Research, Keck Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.,Therapeutics and Biotechnology Division, Drug Discovery Platform Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, Korea.,Department of Biotechnology, Chonnam National University, Yeosu, Korea
| | - Mingyang Cai
- Broad Center for Regenerative Medicine and Stem Cell Research, Keck Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Grace Lee
- Broad Center for Regenerative Medicine and Stem Cell Research, Keck Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Tong Zhao
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaofeng Song
- Department of Biomedical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | | | | | - Min Yu
- Broad Center for Regenerative Medicine and Stem Cell Research, Keck Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Wange Lu
- Broad Center for Regenerative Medicine and Stem Cell Research, Keck Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.,State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China
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6
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Tillotson R, Bird A. The Molecular Basis of MeCP2 Function in the Brain. J Mol Biol 2020; 432:1602-1623. [PMID: 31629770 DOI: 10.1016/j.jmb.2019.10.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/14/2022]
Abstract
MeCP2 is a reader of the DNA methylome that occupies a large proportion of the genome due to its high abundance and the frequency of its target sites. It has been the subject of extensive study because of its link with 'MECP2-related disorders', of which Rett syndrome is the most prevalent. This review integrates evidence from patient mutation data with results of experimental studies using mouse models, cell lines and in vitro systems to critically evaluate our understanding of MeCP2 protein function. Recent evidence challenges the idea that MeCP2 is a multifunctional hub that integrates diverse processes to underpin neuronal function, suggesting instead that its primary role is to recruit the NCoR1/2 co-repressor complex to methylated sites in the genome, leading to dampening of gene expression.
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Affiliation(s)
- Rebekah Tillotson
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada; Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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7
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DNA Modification Readers and Writers and Their Interplay. J Mol Biol 2019:S0022-2836(19)30718-1. [PMID: 31866298 DOI: 10.1016/j.jmb.2019.12.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 11/28/2019] [Accepted: 12/05/2019] [Indexed: 12/15/2022]
Abstract
Genomic DNA is modified in a postreplicative manner and several modifications, the enzymes responsible for their deposition as well as proteins that read these modifications, have been described. Here, we focus on the impact of DNA modifications on the DNA helix and review the writers and readers of cytosine modifications and how they interplay to shape genome composition, stability, and function.
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8
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Lee TH. Physical Chemistry of Epigenetics: Single-Molecule Investigations. J Phys Chem B 2019; 123:8351-8362. [PMID: 31404497 PMCID: PMC6790939 DOI: 10.1021/acs.jpcb.9b06214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/03/2019] [Indexed: 02/06/2023]
Abstract
The nucleosome is the fundamental building block of the eukaryotic genome, composed of an ∼147 base-pair DNA fragment wrapping around an octameric histone protein core. DNA and histone proteins are targets of enzymatic chemical modifications that serve as signals for gene regulation. These modifications are often referred to as epigenetic modifications that govern gene activities without altering the DNA sequence. Although the term epigenetics initially required inheritability, it now frequently includes noninherited histone modifications associated with gene regulation. Important epigenetic modifications for healthy cell growth and proliferation include DNA methylation, histone acetylation, methylation, phosphorylation, ubiquitination, and SUMOylation (SUMO = Small Ubiquitin-like Modifier). Our research focuses on the biophysical roles of these modifications in altering the structure and structural dynamics of the nucleosome and their implications in gene regulation mechanisms. As the changes are subtle and complex, we employ various single-molecule fluorescence approaches for their investigations. Our investigations revealed that these modifications induce changes in the structure and structural dynamics of the nucleosome and their thermodynamic and kinetic stabilities. We also suggested the implications of these changes in gene regulation mechanisms that are the foci of our current and future research.
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Affiliation(s)
- Tae-Hee Lee
- Department of Chemistry, The
Pennsylvania State University, University Park 16803, Pennsylvania, United States
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9
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Ohashi M, Korsakova E, Allen D, Lee P, Fu K, Vargas BS, Cinkornpumin J, Salas C, Park JC, Germanguz I, Langerman J, Chronis C, Kuoy E, Tran S, Xiao X, Pellegrini M, Plath K, Lowry WE. Loss of MECP2 Leads to Activation of P53 and Neuronal Senescence. Stem Cell Reports 2019; 10:1453-1463. [PMID: 29742391 PMCID: PMC5995366 DOI: 10.1016/j.stemcr.2018.04.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 01/15/2023] Open
Abstract
To determine the role for mutations of MECP2 in Rett syndrome, we generated isogenic lines of human induced pluripotent stem cells, neural progenitor cells, and neurons from patient fibroblasts with and without MECP2 expression in an attempt to recapitulate disease phenotypes in vitro. Molecular profiling uncovered neuronal-specific gene expression changes, including induction of a senescence-associated secretory phenotype (SASP) program. Patient-derived neurons made without MECP2 showed signs of stress, including induction of P53, and senescence. The induction of P53 appeared to affect dendritic branching in Rett neurons, as P53 inhibition restored dendritic complexity. The induction of P53 targets was also detectable in analyses of human Rett patient brain, suggesting that this disease-in-a-dish model can provide relevant insights into the human disorder. Development of a patient-specific model of human Rett syndrome Loss of function of MECP2 leads to induction of p53 MECP2 null neurons show evidence of cellular senescence Inhibition of p53 can restore dendritic branching in MECP2 null neurons
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Affiliation(s)
- Minori Ohashi
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center for Regenerative Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Elena Korsakova
- Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA
| | - Denise Allen
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Peiyee Lee
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Kai Fu
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Benni S Vargas
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Jessica Cinkornpumin
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Carlos Salas
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Jenny C Park
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Igal Germanguz
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Justin Langerman
- Department of Biological Chemistry, UCLA, Los Angeles, CA 90095, USA
| | | | - Edward Kuoy
- Department of Biological Chemistry, UCLA, Los Angeles, CA 90095, USA
| | - Stephen Tran
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA 90095, USA
| | - Xinshu Xiao
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA 90095, USA
| | - Matteo Pellegrini
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Kathrin Plath
- Department of Biological Chemistry, UCLA, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center for Regenerative Medicine, UCLA, Los Angeles, CA 90095, USA.
| | - William E Lowry
- Department of Molecular Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center for Regenerative Medicine, UCLA, Los Angeles, CA 90095, USA; Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA.
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10
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Nieto SJ, Kosten TA. Who's your daddy? Behavioral and epigenetic consequences of paternal drug exposure. Int J Dev Neurosci 2019; 78:109-121. [PMID: 31301337 DOI: 10.1016/j.ijdevneu.2019.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/11/2019] [Accepted: 07/08/2019] [Indexed: 12/11/2022] Open
Abstract
Substance use disorders (SUDs) reflect genetic and environmental factors. While identifying reliable genetic variants that predispose individuals to developing SUDs has been challenging, epigenetic factors may also contribute to the heritability of SUDs. Familial drug use associates with a wide range of problems in children, including an increased risk for developing a SUD. The implications of maternal drug use on offspring development are a well-studied area; however, paternal drug use prior to conception has received relatively little attention. Paternal exposure to several environmental stimuli (i.e. stress or diet manipulations) results in behavioral and epigenetic changes in offspring. The purpose of this review is to determine the state of the preclinical literature on the behavioral and epigenetic consequences of paternal drug exposure. Drug-sired offspring show several developmental and physiological abnormalities. These offspring also show deficits in cognitive and emotional domains. Examining sensitivity to drugs in offspring is a growing area of research. Drug-sired offspring are resistant to the rewarding and reinforcing properties of drugs. However, greater paternal motivation for the drug, combined with high drug intake, can result in addiction-like behaviors in offspring. Drug-sired offspring also show altered histone modifications and DNA methylation levels of imprinted genes and microRNAs; epigenetic-mediated changes were also noted in genes related to glutamatergic and neurotrophic factor signaling. In some instances, drug use resulted in aberrant epigenetic modifications in sire sperm, and these changes were maintained in the brains of offspring. Thus, paternal drug exposure has long-lasting consequences that include altered drug sensitivity in subsequent generations. We discuss factors (i.e. maternal behaviors) that may moderate these paternal drug-induced effects as well as ideas for future directions.
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Affiliation(s)
- Steven J Nieto
- University of Houston, Department of Psychology & Texas Institute for Measurement, Evaluation and Statistics (TIMES), Houston, TX, 77204-6022, United States
| | - Therese A Kosten
- University of Houston, Department of Psychology & Texas Institute for Measurement, Evaluation and Statistics (TIMES), Houston, TX, 77204-6022, United States
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11
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Liu K, Lei M, Wu Z, Gan B, Cheng H, Li Y, Min J. Structural analyses reveal that MBD3 is a methylated CG binder. FEBS J 2019; 286:3240-3254. [PMID: 30980593 DOI: 10.1111/febs.14850] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/19/2019] [Accepted: 04/11/2019] [Indexed: 12/17/2022]
Abstract
The MBD3, a methyl-CpG-binding domain (MBD)-containing protein, is a core subunit of the Mi-2/NuRD complex. Recent reports show that MBD3 recognizes both methylated CG (mCG)- and hydroxymethylated CG (hmCG)-containing DNA, with a preference for hmCG. However, whether the MBD3-MBD indeed has methyl-CG-binding ability is controversial. In this study, we provided the structural basis to support the ability of MBD3-MBD to bind mCG-containing DNA. We found that the MBD3-MBD bound to mCG-containing DNA through two conserved arginine fingers, and preferentially bound to mCG over hmCG, similar to other methyl-CpG-binding MBD proteins. Compared to its closest homolog MBD2, the tyrosine-to-phenylalanine substitution at Phe34 of MBD3 is responsible for a weaker mCG DNA binding ability. Based on the complex structure of MBD3-MBD with a nonpalindromic AmCGC DNA, we suggest that all the mCG-binding MBD domains can recognize mCG-containing DNA without orientation selectivity, consistent with our observations that the sequences outside the mCG dinucleotide do not affect mCG DNA binding significantly. DNA cytosine methylation is evolutionarily conserved in most metazoans, and most invertebrates have only one MBD gene, MBD2/3. We also looked into the mCG DNA binding ability of some invertebrates MBD2/3 and found that the conserved arginine fingers and a conserved structural fold are required for methylated DNA binding by MBD2/3-MBDs in invertebrates. Hence, our results demonstrate that mCG-binding arginine fingers embedded into a conserved structural fold are essential structural features for MBD2/3s binding to methylated DNA among metazoans.
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Affiliation(s)
- Ke Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China.,Structural Genomics Consortium, University of Toronto, Canada
| | - Ming Lei
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China.,Structural Genomics Consortium, University of Toronto, Canada
| | - Zhibin Wu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Bing Gan
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Harry Cheng
- Structural Genomics Consortium, University of Toronto, Canada
| | - Yanjun Li
- Structural Genomics Consortium, University of Toronto, Canada
| | - Jinrong Min
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China.,Structural Genomics Consortium, University of Toronto, Canada.,Department of Physiology, University of Toronto, Canada
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12
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Electrochemical determination of the activity of DNA methyltransferase based on the methyl binding domain protein and a customized modular detector. Mikrochim Acta 2019; 186:229. [DOI: 10.1007/s00604-019-3309-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 02/11/2019] [Indexed: 12/31/2022]
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13
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Numata A, Kwok HS, Kawasaki A, Li J, Zhou QL, Kerry J, Benoukraf T, Bararia D, Li F, Ballabio E, Tapia M, Deshpande AJ, Welner RS, Delwel R, Yang H, Milne TA, Taneja R, Tenen DG. The basic helix-loop-helix transcription factor SHARP1 is an oncogenic driver in MLL-AF6 acute myelogenous leukemia. Nat Commun 2018; 9:1622. [PMID: 29692408 PMCID: PMC5915391 DOI: 10.1038/s41467-018-03854-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 03/19/2018] [Indexed: 12/17/2022] Open
Abstract
Acute Myeloid Leukemia (AML) with MLL gene rearrangements demonstrate unique gene expression profiles driven by MLL-fusion proteins. Here, we identify the circadian clock transcription factor SHARP1 as a novel oncogenic target in MLL-AF6 AML, which has the worst prognosis among all subtypes of MLL-rearranged AMLs. SHARP1 is expressed solely in MLL-AF6 AML, and its expression is regulated directly by MLL-AF6/DOT1L. Suppression of SHARP1 induces robust apoptosis of human MLL-AF6 AML cells. Genetic deletion in mice delays the development of leukemia and attenuated leukemia-initiating potential, while sparing normal hematopoiesis. Mechanistically, SHARP1 binds to transcriptionally active chromatin across the genome and activates genes critical for cell survival as well as key oncogenic targets of MLL-AF6. Our findings demonstrate the unique oncogenic role for SHARP1 in MLL-AF6 AML. Gene fusions involving MLL and different partner genes define unique subgroups of acute myelogenous leukemia, but the mechanisms underlying specific subgroups are not fully clear. Here the authors elucidate the mechanisms of MLL-AF6 induced transformation, providing a distinct pathway that involves SHARP1 as a critical target.
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Affiliation(s)
- Akihiko Numata
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Hui Si Kwok
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Akira Kawasaki
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Jia Li
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Qi-Ling Zhou
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Jon Kerry
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, NIHR Oxford Biomedical Research Centre Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Touati Benoukraf
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Deepak Bararia
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Feng Li
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Erica Ballabio
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, NIHR Oxford Biomedical Research Centre Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Marta Tapia
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, NIHR Oxford Biomedical Research Centre Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | | | - Robert S Welner
- Division of Hematology/Oncology, The University of Alabama at Birmingham, Comprehensive Cancer Center, Birmingham, AL, 35294, USA
| | - Ruud Delwel
- Department of Hematology, Erasmus University Medical Center, 3015 GE, Rotterdam, The Netherlands
| | - Henry Yang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Thomas A Milne
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, NIHR Oxford Biomedical Research Centre Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Reshma Taneja
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore.
| | - Daniel G Tenen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore. .,Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, 02115, USA.
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14
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He CC, Wang ZY, Tian K, Liu W, Li YB, Hong Y, Yu LX, Pang W, Jiang YG, Liu YQ. DNA methylation mechanism of intracellular zinc deficiency-induced injury in primary hippocampal neurons in the rat brain. Nutr Neurosci 2017; 21:478-486. [DOI: 10.1080/1028415x.2017.1312090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Cong-cong He
- College of Life Sciences, Nankai University, Tianjin 300071, China
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Zi-yu Wang
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Kun Tian
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Wei Liu
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Yi-bo Li
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Yan Hong
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Li-xia Yu
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Wei Pang
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Yu-gang Jiang
- Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, China
| | - Yan-qiang Liu
- College of Life Sciences, Nankai University, Tianjin 300071, China
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15
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Grzybek M, Golonko A, Walczak M, Lisowski P. Epigenetics of cell fate reprogramming and its implications for neurological disorders modelling. Neurobiol Dis 2016; 99:84-120. [PMID: 27890672 DOI: 10.1016/j.nbd.2016.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 11/03/2016] [Accepted: 11/21/2016] [Indexed: 02/06/2023] Open
Abstract
The reprogramming of human induced pluripotent stem cells (hiPSCs) proceeds in a stepwise manner with reprogramming factors binding and epigenetic composition changes during transition to maintain the epigenetic landscape, important for pluripotency. There arises a question as to whether the aberrant epigenetic state after reprogramming leads to epigenetic defects in induced stem cells causing unpredictable long term effects in differentiated cells. In this review, we present a comprehensive view of epigenetic alterations accompanying reprogramming, cell maintenance and differentiation as factors that influence applications of hiPSCs in stem cell based technologies. We conclude that sample heterogeneity masks DNA methylation signatures in subpopulations of cells and thus believe that beside a genetic evaluation, extensive epigenomic screening should become a standard procedure to ensure hiPSCs state before they are used for genome editing and differentiation into neurons of interest. In particular, we suggest that exploitation of the single-cell composition of the epigenome will provide important insights into heterogeneity within hiPSCs subpopulations to fast forward development of reliable hiPSC-based analytical platforms in neurological disorders modelling and before completed hiPSC technology will be implemented in clinical approaches.
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Affiliation(s)
- Maciej Grzybek
- Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-950 Lublin, Poland; Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Postępu 36A, 05-552 Magdalenka, Poland.
| | - Aleksandra Golonko
- Department of Biotechnology, Faculty of Civil and Environmental Engineering, Bialystok University of Technology, Wiejska 45E, 15-351 Bialystok, Poland.
| | - Marta Walczak
- Department of Animal Behavior, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Postępu 36A, 05-552 Magdalenka, Poland.
| | - Pawel Lisowski
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Postępu 36A, 05-552 Magdalenka, Poland; iPS Cell-Based Disease Modelling Group, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Association, Robert-Rössle-Str. 10, 13092 Berlin, Germany.
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16
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Ludwig AK, Zhang P, Cardoso MC. Modifiers and Readers of DNA Modifications and Their Impact on Genome Structure, Expression, and Stability in Disease. Front Genet 2016; 7:115. [PMID: 27446199 PMCID: PMC4914596 DOI: 10.3389/fgene.2016.00115] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/06/2016] [Indexed: 12/16/2022] Open
Abstract
Cytosine base modifications in mammals underwent a recent expansion with the addition of several naturally occurring further modifications of methylcytosine in the last years. This expansion was accompanied by the identification of the respective enzymes and proteins reading and translating the different modifications into chromatin higher order organization as well as genome activity and stability, leading to the hypothesis of a cytosine code. Here, we summarize the current state-of-the-art on DNA modifications, the enzyme families setting the cytosine modifications and the protein families reading and translating the different modifications with emphasis on the mouse protein homologs. Throughout this review, we focus on functional and mechanistic studies performed on mammalian cells, corresponding mouse models and associated human diseases.
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Affiliation(s)
- Anne K Ludwig
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Darmstadt Germany
| | - Peng Zhang
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Darmstadt Germany
| | - M C Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Darmstadt Germany
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17
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Don't worry; be informed about the epigenetics of anxiety. Pharmacol Biochem Behav 2016; 146-147:60-72. [PMID: 27189589 DOI: 10.1016/j.pbb.2016.05.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/06/2016] [Accepted: 05/12/2016] [Indexed: 01/10/2023]
Abstract
Epigenetic processes regulate gene expression independent of the DNA sequence and are increasingly being investigated as contributors to the development of behavioral disorders. Environmental insults, such as stress, diet, or toxin exposure, can affect epigenetic mechanisms, including chromatin remodeling, DNA methylation, and non-coding RNAs that, in turn, alter the organism's phenotype. In this review, we examine the literature, derived at both the preclinical (animal) and clinical (human) levels, on epigenetic alterations associated with anxiety disorders. Using animal models of anxiety, researchers have identified epigenetic changes in several limbic and cortical brain regions known to be involved in stress and emotion responses. Environmental manipulations have been imposed prior to conception, during prenatal or early postnatal periods, and at juvenile and adult ages. Time of perturbation differentially affects the epigenome and many changes are brain region-specific. Although some sex-dependent effects are reported in animal studies, more research employing both sexes is needed particularly given that females exhibit a disproportionate number of anxiety disorders. The human literature is in its infancy but does reveal some epigenetic associations with anxiety behaviors and disorders. In particular, effects in monoaminergic systems are seen in line with evidence from etiological and treatment research. Further, there is evidence that epigenetic changes may be inherited to affect subsequent generations. We speculate on how epigenetic processes may interact with genetic contributions to inform prevention and treatment strategies for those who are at risk for or have anxiety disorders.
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18
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Poh WJ, Wee CPP, Gao Z. DNA Methyltransferase Activity Assays: Advances and Challenges. Am J Cancer Res 2016; 6:369-91. [PMID: 26909112 PMCID: PMC4737724 DOI: 10.7150/thno.13438] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/12/2015] [Indexed: 12/28/2022] Open
Abstract
DNA methyltransferases (MTases), a family of enzymes that catalyse the methylation of DNA, have a profound effect on gene regulation. A large body of evidence has indicated that DNA MTase is potentially a predictive biomarker closely associated with genetic disorders and genetic diseases like cancer. Given the attention bestowed onto DNA MTases in molecular biology and medicine, highly sensitive detection of DNA MTase activity is essential in determining gene regulation, epigenetic modification, clinical diagnosis and therapeutics. Conventional techniques such as isotope labelling are effective, but they often require laborious sample preparation, isotope labelling, sophisticated equipment and large amounts of DNA, rendering them unsuitable for uses at point-of-care. Simple, portable, highly sensitive and low-cost assays are urgently needed for DNA MTase activity screening. In most recent technological advances, many alternative DNA MTase activity assays such as fluorescent, electrochemical, colorimetric and chemiluminescent assays have been proposed. In addition, many of them are coupled with nanomaterials and/or enzymes to significantly enhance their sensitivity. Herein we review the progress in the development of DNA MTase activity assays with an emphasis on assay mechanism and performance with some discussion on challenges and perspectives. It is hoped that this article will provide a broad coverage of DNA MTase activity assays and their latest developments and open new perspectives toward the development of DNA MTase activity assays with much improved performance for uses in molecular biology and clinical practice.
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19
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Tajima S, Suetake I, Takeshita K, Nakagawa A, Kimura H. Domain Structure of the Dnmt1, Dnmt3a, and Dnmt3b DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 945:63-86. [PMID: 27826835 DOI: 10.1007/978-3-319-43624-1_4] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In mammals, three DNA methyltransferases, Dnmt1, Dnmt3a, and Dnmt3b, have been identified. Dnmt3a and Dnmt3b are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. Dnmt3-like (Dnmt3l), which is a member of the Dnmt3 family but does not possess DNA methylation activity, was reported to be indispensable for global methylation in germ cells. Once the DNA methylation patterns are established, maintenance-type DNA methyltransferase Dnmt1 faithfully propagates them to the next generation via replication. All Dnmts possess multiple domains, and in this chapter, the structures and functions of these domains are described.
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Affiliation(s)
- Shoji Tajima
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Isao Suetake
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- CREST/AMED, 1-7-1 Otemachi, Chiyoda-ku, Tokyo, 100-0004, Japan
| | - Kohei Takeshita
- Laboratory of Supramolecular Crystallography, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- PRESTO/JST, Saitama, 332-0012, Japan
| | - Atsushi Nakagawa
- Laboratory of Supramolecular Crystallography, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hironobu Kimura
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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20
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Vaissière T, Miller CA. DNA methylation: dynamic and stable regulation of memory. Biomol Concepts 2015; 2:459-67. [PMID: 25962048 DOI: 10.1515/bmc.2011.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 09/17/2011] [Indexed: 12/26/2022] Open
Abstract
Epigenetic mechanisms have emerged as a central process in learning and memory. Histone modifications and DNA methy-lation are epigenetic events that can mediate gene transcription. Interesting features of these epigenetic changes are their transient and long lasting potential. Recent advances in neuroscience suggest that DNA methylation is both dynamic and stable, mediating the formation and maintenance of memory. In this review, we will further illustrate the recent hypothesis that DNA methylation participates in the transcriptional regulation necessary for memory.
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21
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Liu Y, Zheng W, Zhang W, Chen N, Liu Y, Chen L, Zhou X, Chen X, Zheng H, Li X. Photoaffinity labeling of transcription factors by DNA-templated crosslinking. Chem Sci 2015; 6:745-751. [PMID: 28706637 PMCID: PMC5494549 DOI: 10.1039/c4sc01953a] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/30/2014] [Indexed: 12/24/2022] Open
Abstract
Characterization of transcription factor-DNA interaction is of high importance in elucidating the molecular mechanisms of gene transcriptions. DNA-based affinity probes were developed to capture and identify transcription factors by covalent crosslinking; however, the requirement of a crosslinker on the affinity probe remains a disadvantage, as the crosslinker itself often interferes with the protein-DNA interactions. We report a dual-probe method able to capture DNA-binding transcription factors with unmodified protein-binding sites in scenarios where conventional probes have failed. We have also shown the method's converse application in selecting specific transcription factor-binding DNA sequences from a probe library and its extension to studying proteins recognizing epigenetic marks. This study may provide a new tool for exploring DNA-binding proteins in biology.
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Affiliation(s)
- Ying Liu
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Wenlu Zheng
- Key Laboratory of Chemical Genomics , School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen , China 518055
| | - Wan Zhang
- Key Laboratory of Chemical Genomics , School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen , China 518055
| | - Nan Chen
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Yang Liu
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Li Chen
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Xiaozhou Zhou
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Xingshuo Chen
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Haifeng Zheng
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
| | - Xiaoyu Li
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education , Beijing National Laboratory of Molecular Sciences , College of Chemistry and Molecular Engineering , Peking University , Beijing , China 100871 .
- Key Laboratory of Chemical Genomics , School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen , China 518055
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22
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Wakabayashi T, Hidaka R, Fujimaki S, Asashima M, Kuwabara T. MicroRNAs and epigenetics in adult neurogenesis. ADVANCES IN GENETICS 2014; 86:27-44. [PMID: 25172344 DOI: 10.1016/b978-0-12-800222-3.00002-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Neurogenesis occurs throughout adulthood in the mammalian brain. Neural stem cells (NSCs) exist in three distinct areas of the brain: the subventricular zone, the olfactory bulb, and the dentate gyrus of the hippocampus. MicroRNAs (miRNAs) are small noncoding RNA molecules that posttranscriptionally regulate gene expression. Epigenetic regulation of gene expression, which includes DNA methylation and histone modification, plays a significant role in modulating NSC proliferation and differentiation. However, the functions of miRNAs in neurogenesis are just beginning to be understood. Based on the recent literature, miRNAs are suggested to play an important role in the epigenetic regulation of NSCs and differentiation of lineage populations, which include neurons, astrocytes, and oligodendrocytes. Recent studies have elucidated the roles of miRNAs in embryonic and adult neurogenesis, specifically, their involvement in stem cell maintenance and differentiation, neuronal maturation and neurite outgrowth, dendritogenesis, and spine formation. The cross-talk between miRNAs and epigenetic regulators appears to modulate neurogenesis in the adult mammalian brain. Since the dysfunction in miRNA machinery contributes to many types of neurodegenerative disorders, a better understanding of how miRNAs influence the neurogenesis and differentiation may offer novel targets for therapeutic application.
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Affiliation(s)
- Tamami Wakabayashi
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Science City, Ibaraki, Japan; Physical Education, Health and Sport Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Ryo Hidaka
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Science City, Ibaraki, Japan; Physical Education, Health and Sport Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shin Fujimaki
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Science City, Ibaraki, Japan; Physical Education, Health and Sport Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Makoto Asashima
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Science City, Ibaraki, Japan; Physical Education, Health and Sport Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tomoko Kuwabara
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Science City, Ibaraki, Japan; Physical Education, Health and Sport Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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23
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Abstract
Vertebrate DNA can be chemically modified by methylation of the 5 position of the cytosine base in the context of CpG dinucleotides. This modification creates a binding site for MBD (methyl-CpG-binding domain) proteins which target chromatin-modifying activities that are thought to contribute to transcriptional repression and maintain heterochromatic regions of the genome. In contrast with DNA methylation, which is found broadly across vertebrate genomes, non-methylated DNA is concentrated in regions known as CGIs (CpG islands). Recently, a family of proteins which encode a ZF-CxxC (zinc finger-CxxC) domain have been shown to specifically recognize non-methylated DNA and recruit chromatin-modifying activities to CGI elements. For example, CFP1 (CxxC finger protein 1), MLL (mixed lineage leukaemia protein), KDM (lysine demethylase) 2A and KDM2B regulate lysine methylation on histone tails, whereas TET (ten-eleven translocation) 1 and TET3 hydroxylate methylated cytosine bases. In the present review, we discuss the most recent advances in our understanding of how ZF-CxxC domain-containing proteins recognize non-methylated DNA and describe their role in chromatin modification at CGIs.
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Jeong KW, Andreu-Vieyra C, You JS, Jones PA, Stallcup MR. Establishment of active chromatin structure at enhancer elements by mixed-lineage leukemia 1 to initiate estrogen-dependent gene expression. Nucleic Acids Res 2013; 42:2245-56. [PMID: 24288367 PMCID: PMC3936730 DOI: 10.1093/nar/gkt1236] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A number of genome-wide analyses have revealed that estrogen receptor α binding to and regulation of its target genes correlate with binding of FOXA1, a pioneer factor, to nearby DNA sites in MCF-7 breast cancer cells. The enhancer element-specific histone H3K4me1/2 mark is enriched at the specific FOXA1/ERα recruitment sites in chromatin, but the mechanism by which these enhancer marks are established in chromatin before hormone treatment is unclear. Here, we show that mixed-lineage leukemia 1 (MLL1) protein is a key determinant that maintains permissive chromatin structure of the TFF1 enhancer region. MLL1 occupies the TFF1 enhancer region and methylates H3K4 before hormone stimulation. In vitro, MLL1 binds directly to the CpG-rich region of the TFF1 enhancer, and its binding is dependent on hypomethylation of DNA. Furthermore, the depletion of MLL1 in MCF-7 cells results in a dramatic decrease of chromatin accessibility and recruitment of FOXA1 and ERα to the enhancer element. Our study defines the mechanism by which MLL1 nucleates histone H3K4 methylation marks in CpG-enriched regions to maintain permissive chromatin architecture and allow FOXA1 and estrogen receptor α binding to transcriptional regulatory sites in breast cancer cells.
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Affiliation(s)
- Kwang Won Jeong
- Gachon Institute of Pharmaceutical Sciences, College of Pharmacy, Gachon University, Incheon 406-840, Republic of Korea, Departments of Urology and Biochemistry and Molecular Biology, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9176, USA, Department of Biochemistry, School of Medicine, Konkuk University, Seoul 143-701, Republic of Korea and Department of Biochemistry and Molecular Biology, USC/Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9176, USA
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25
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Alvarado S, Wyglinski J, Suderman M, Andrews SA, Szyf M. Methylated DNA binding domain protein 2 (MBD2) coordinately silences gene expression through activation of the microRNA hsa-mir-496 promoter in breast cancer cell line. PLoS One 2013; 8:e74009. [PMID: 24204564 PMCID: PMC3812180 DOI: 10.1371/journal.pone.0074009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/25/2013] [Indexed: 12/31/2022] Open
Abstract
Methylated DNA binding protein 2 (MBD2) binds methylated promoters and suppresses transcription in cis through recruitment of a chromatin modification repressor complex. We show here a new mechanism of action for MBD2: suppression of gene expression indirectly through activation of microRNA hsa-mir-496. Overexpression of MBD2 in breast epithelial cell line MCF-10A results in induced expression and demethylation of hsa-mir-496 while depletion of MBD2 in a human breast cancer cell lines MCF-7 and MDA-MB231 results in suppression of hsa-mir-496. Activation of hsa-mir-496 by MBD2 is associated with silencing of several of its target genes while depletion of MBD2 leads to induction of hsa-mir-496 target genes. Depletion of hsa-mir-496 by locked nucleic acid (LNA) antisense oligonucleotide leads to activation of these target genes in MBD2 overexpressing cells supporting that hsa-mir-496 is mediating in part the effects of MBD2 on gene expression. We demonstrate that MBD2 binds the promoter of hsa-mir-496 in MCF-10A, MCF-7 and MDA-MB-231 cells and that it activates an in vitro methylated hsa-mir-496 promoter driving a CG-less luciferase reporter in a transient transfection assay. The activation of hsa-mir-496 is associated with reduced methylation of the promoter. Taken together these results describe a novel cascade for gene regulation by DNA methylation whereby activation of a methylated microRNA by MBD2 that is associated with loss of methylation triggers repression of downstream targets.
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Affiliation(s)
- Sebastian Alvarado
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Joanne Wyglinski
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Matthew Suderman
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
- McGill Centre for Bioinformatics, McGill University, Montreal, Quebec, Canada
| | - Stephen A. Andrews
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Moshe Szyf
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
- Sackler Program for Epigenetics and Developmental Psychobiology, McGill University, Montreal, Quebec, Canada
- * E-mail:
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An electrochemical assay for DNA methylation, methyltransferase activity and inhibitor screening based on methyl binding domain protein. Biosens Bioelectron 2013; 41:492-7. [DOI: 10.1016/j.bios.2012.09.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 09/04/2012] [Accepted: 09/09/2012] [Indexed: 11/18/2022]
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27
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Jung JS, Jee MK, Cho HT, Choi JI, Im YB, Kwon OH, Kang SK. MBD6 is a direct target of Oct4 and controls the stemness and differentiation of adipose tissue-derived stem cells. Cell Mol Life Sci 2013; 70:711-28. [PMID: 23052207 PMCID: PMC11114067 DOI: 10.1007/s00018-012-1157-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 08/29/2012] [Accepted: 08/30/2012] [Indexed: 01/07/2023]
Abstract
Argonaute 2 (Ago2) is a pivotal regulator of cell fate in adult stem cells. Its expression is significantly downregulated in late passages of cells, concomitant with a prominent increase in Ago2 cytosolic localization in single cells. Nuclear localization of Ago2 is crucial for the survival, proliferation, and differentiation of hATSCs (human adipose tissue-derived stem cells), mediated by the specific binding of the regulatory regions of functional genes, which positively or negatively altered gene expression. Ago2 targets genes that control stemness, reactive oxygen species scavenging, and microRNA expression, all of which are crucial for hATSC survival and self-renewal. Ago2 promotes cell proliferation and self-renewal by activating the expression of octamer-binding transcription factor 4 (Oct4). We confirmed the direct regulation of Oct4 activity by Ago2, as indicated by the results of the ChIP analysis. Methyl-CpG-binding protein 6 (MBD6) was detected as an Oct4 regulatory gene. As predicted, knockdown of MBD6 expression attenuated cell proliferation and eventually induced cell death. We hypothesized that MBD6 functions downstream of Oct4 in the regulation of stemness-related genes, cell proliferation, self-renewal activity, and survival. MBD6 also promoted cell transdifferentiation into neural and endodermal β-cells while significantly attenuating differentiation into the mesodermal lineage. We demonstrate that MBD6 is regulated by Ago2 via an interaction with Oct4, which alters self-renewal and gene expression in hATSCs. MBD6 was promoted cell proliferation through a novel set of signal mediators that may influence differentiation by repressing MBD2 and MBD3, which are possibly recruited by germ cell nuclear factor (GCNF).
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Affiliation(s)
- Jin Sun Jung
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Min Ki Jee
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Hyun Tae Cho
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Jee In Choi
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Young Bin Im
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Oh Hyun Kwon
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Soo Kyung Kang
- Laboratory of Stem Cell Biology, Department of Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
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McMurray EN, Schmidt JV. Identification of imprinting regulators at the Meg3 differentially methylated region. Genomics 2012; 100:184-94. [PMID: 22709555 DOI: 10.1016/j.ygeno.2012.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 04/13/2012] [Accepted: 06/04/2012] [Indexed: 01/04/2023]
Abstract
Genomic imprinting at the Delta-like 1 (Dlk1)-Maternally expressed gene 3 (Meg3) locus is regulated by the Meg3 differentially methylated region (DMR), but the mechanism by which this DMR acts is unknown. The goal of this study was to analyze the Meg3 DMR during imprinting establishment and maintenance for the presence of histone modifications and trans-acting DNA binding proteins using chromatin immunoprecipitation. In embryonic stem (ES) cells, where Meg3 is biallelically expressed, the DMR showed variable DNA methylation, with biallelic methylation at one region but paternal allele-specific methylation at another. All histone modifications detected at the Meg3 DMR of ES cells were biallelic. In embryonic day 12.5 (e12.5) embryos, where Meg3 is maternally expressed, the paternal Meg3 DMR was methylated, and activating histone modifications were specific to the maternal DMR. DNA-binding proteins that represent potential regulatory factors were identified in both ES cells and embryos.
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Affiliation(s)
- Erin N McMurray
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
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29
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Parakalan R, Jiang B, Nimmi B, Janani M, Jayapal M, Lu J, Tay SSW, Ling EA, Dheen ST. Transcriptome analysis of amoeboid and ramified microglia isolated from the corpus callosum of rat brain. BMC Neurosci 2012; 13:64. [PMID: 22697290 PMCID: PMC3441342 DOI: 10.1186/1471-2202-13-64] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 05/16/2012] [Indexed: 02/03/2023] Open
Abstract
Background Microglia, the resident immune cells of the central nervous system (CNS), have two distinct phenotypes in the developing brain: amoeboid form, known to be amoeboid microglial cells (AMC) and ramified form, known to be ramified microglial cells (RMC). The AMC are characterized by being proliferative, phagocytic and migratory whereas the RMC are quiescent and exhibit a slow turnover rate. The AMC transform into RMC with advancing age, and this transformation is indicative of the gradual shift in the microglial functions. Both AMC and RMC respond to CNS inflammation, and they become hypertrophic when activated by trauma, infection or neurodegenerative stimuli. The molecular mechanisms and functional significance of morphological transformation of microglia during normal development and in disease conditions is not clear. It is hypothesized that AMC and RMC are functionally regulated by a specific set of genes encoding various signaling molecules and transcription factors. Results To address this, we carried out cDNA microarray analysis using lectin-labeled AMC and RMC isolated from frozen tissue sections of the corpus callosum of 5-day and 4-week old rat brain respectively, by laser capture microdissection. The global gene expression profiles of both microglial phenotypes were compared and the differentially expressed genes in AMC and RMC were clustered based on their functional annotations. This genome wide comparative analysis identified genes that are specific to AMC and RMC. Conclusions The novel and specific molecules identified from the trancriptome explains the quiescent state functioning of microglia in its two distinct morphological states.
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Affiliation(s)
- Rangarajan Parakalan
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Blk MD10, 4 Medical Drive, Singapore, 117597, Singapore
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Acevedo LG, Sanz A, Jelinek MA. Novel DNA binding domain-based assays for detection of methylated and nonmethylated DNA. Epigenomics 2012; 3:93-101. [PMID: 22126156 DOI: 10.2217/epi.10.69] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Methylation of cytosine in the context of CpG dinucleotides is an epigenetic phenomenon in eukaryotes that plays important roles in genome function and transcription regulation. Aberrant changes in DNA methylation is an important feature of several human diseases such as cancer and neurological disorders. These discoveries have opened a new field of new therapies and diagnostics. During recent years, there has been a revolution in DNA methylation analysis technologies. This article focuses on methods with which to study DNA methylation that employ protein domains that specifically recognize either 5-methyl-cytosine in the CpG context or nonmethylated DNA, and methods developed for the detection of 5-hydroxymethylcytosine, the recently described epigenetic mark known as the sixth base of the epigenome.
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Affiliation(s)
- Luis G Acevedo
- Active Motif, Inc., 1914 Palomar Oaks Way, Suite 150, Carlsbad, CA 92008, USA.
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31
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Albalat R, Martí-Solans J, Cañestro C. DNA methylation in amphioxus: from ancestral functions to new roles in vertebrates. Brief Funct Genomics 2012; 11:142-55. [PMID: 22389042 DOI: 10.1093/bfgp/els009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In vertebrates, DNA methylation is an epigenetic mechanism that modulates gene transcription, and plays crucial roles during development, cell fate maintenance, germ cell pluripotency and inheritable genome imprinting. DNA methylation might also play a role as a genome defense mechanism against the mutational activity derived from transposon mobility. In contrast to the heavily methylated genomes in vertebrates, most genomes in invertebrates are poorly or just moderately methylated, and the function of DNA methylation remains unclear. Here, we review the DNA methylation system in the cephalochordate amphioxus, which belongs to the most basally divergent group of our own phylum, the chordates. First, surveys of the amphioxus genome database reveal the presence of the DNA methylation machinery, DNA methyltransferases and methyl-CpG-binding domain proteins. Second, comparative genomics and analyses of conserved synteny between amphioxus and vertebrates provide robust evidence that the DNA methylation machinery of amphioxus represents the ancestral toolkit of chordates, and that its expansion in vertebrates was originated by the two rounds of whole-genome duplication that occurred in stem vertebrates. Third, in silico analysis of CpGo/e ratios throughout the amphioxus genome suggests a bimodal distribution of DNA methylation, consistent with a mosaic pattern comprising domains of methylated DNA interspersed with domains of unmethylated DNA, similar to the situation described in ascidians, but radically different to the globally methylated vertebrate genomes. Finally, we discuss potential roles of the DNA methylation system in amphioxus in the context of chordate genome evolution and the origin of vertebrates.
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Mohamed Ariff I, Mitra A, Basu A. Epigenetic regulation of self-renewal and fate determination in neural stem cells. J Neurosci Res 2011; 90:529-39. [DOI: 10.1002/jnr.22804] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 08/18/2011] [Accepted: 09/02/2011] [Indexed: 01/30/2023]
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Khan SI, Aumsuwan P, Khan IA, Walker LA, Dasmahapatra AK. Epigenetic events associated with breast cancer and their prevention by dietary components targeting the epigenome. Chem Res Toxicol 2011; 25:61-73. [PMID: 21992498 DOI: 10.1021/tx200378c] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aberrant epigenetic alterations in the genome such as DNA methylation and chromatin remodeling play a significant role in breast cancer development. Since epigenetic alterations are considered to be more easily reversible compared to genetic changes, epigenetic therapy is potentially very useful in reversing some of these defects. Methylation of CpG islands is an important component of the epigenetic code, and a number of genes become abnormally methylated in breast cancer patients. Currently, several epigenetic-based synthetic drugs that can reduce DNA hypermethylation and histone deacetylation are undergoing preclinical and clinical trials. However, these chemicals are generally very toxic and do not have gene specificity. Epidemiological studies have shown that Asian women are less prone to breast cancer due to their high consumption of soy food than the Caucasian women of western countries. Moreover, complementary/and or alternative medicines are commonly used by Asian populations which are rich in bioactive ingredients known to be chemopreventive against tumorigenesis in general. Examples of such agents include dietary polyphenols, (-)-epigallocatechin-3-gallate (EGCG) from green tea, genistein from soybean, isothiocyanates from plant foods, curcumin from turmeric, resveratrol from grapes, and sulforaphane from cruciferous vegetables. These bioactive components are able to modulate epigenetic events, and their epigenetic targets are known to be associated with breast cancer prevention and therapy. This approach could facilitate the discovery and development of novel drugs for the treatment of breast cancer. In this brief review, we will summarize the epigenetic events associated with breast cancer and the potential of some of these bioactive dietary components to modulate these events and thus afford new therapeutic or preventive approaches.
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Affiliation(s)
- Shabana I Khan
- National Center for Natural Products Research, University of Mississippi, University, Mississippi 38677, United States
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Bartels SJJ, Spruijt CG, Brinkman AB, Jansen PWTC, Vermeulen M, Stunnenberg HG. A SILAC-based screen for Methyl-CpG binding proteins identifies RBP-J as a DNA methylation and sequence-specific binding protein. PLoS One 2011; 6:e25884. [PMID: 21991380 PMCID: PMC3185043 DOI: 10.1371/journal.pone.0025884] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Accepted: 09/13/2011] [Indexed: 11/19/2022] Open
Abstract
Background DNA methylation is an epigenetic modification that plays a crucial role in a variety of biological processes. Methylated DNA is specifically bound by Methyl-CpG Binding Proteins (MBPs). Three different types of MBPs have been identified so far: the Methyl-CpG Binding Domain (MBD) family proteins, three BTB/POZ-Zn-finger proteins, and UHRF1. Most of the known MBPs have been identified via homology with the MBD and Zn-finger domains as present in MeCP2 and Kaiso, respectively. It is conceivable that other proteins are capable of recognizing methylated DNA. Methodology/Principal Findings For the purpose of identifying novel ‘readers’ we set up a methyl-CpG pull-down assay combined with stable-isotope labeling by amino acids in cell culture (SILAC). In a methyl-CpG pull-down with U937 nuclear extracts, we recovered several known MBPs and almost all subunits of the MBD2/NuRD complex as methylation specific binders, providing proof-of-principle. Interestingly, RBP-J, the transcription factor downstream of Notch receptors, also bound the DNA in a methylation dependent manner. Follow-up pull-downs and electrophoretic mobility shift assays (EMSAs) showed that RBP-J binds methylated DNA in the context of a mutated RBP-J consensus motif. Conclusions/Significance The here described SILAC/methyl-CpG pull-down constitutes a new approach to identify potential novel DNAme readers and will advance unraveling of the complete methyl-DNA interactome.
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Affiliation(s)
- Stefanie J. J. Bartels
- Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Cornelia G. Spruijt
- Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Arie B. Brinkman
- Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Pascal W. T. C. Jansen
- Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Michiel Vermeulen
- Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Hendrik G. Stunnenberg
- Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
- * E-mail:
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Svedružić ŽM. Dnmt1 structure and function. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 101:221-54. [PMID: 21507353 DOI: 10.1016/b978-0-12-387685-0.00006-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Dnmt1, the principal DNA methyltransferase in mammalian cells, is a large and a highly dynamic enzyme with multiple regulatory features that can control DNA methylation in cells. This chapter highlights how insights into Dnmt1 structure and function can advance our understanding of DNA methylation in cells. The allosteric site(s) on Dnmt1 can regulate processes of de novo and maintenance DNA methylation in cells. Remaining open questions include which molecules, by what mechanism, bind at the allosteric site(s) in cells? Different phosphorylation sites on Dnmt1 can change its activity or ability to bind DNA target sites. Thirty-one different molecules are currently known to have physical and/or functional interaction with Dnmt1 in cells. The Dnmt1 structure and enzymatic mechanism offer unique insights into those interactions. The interacting molecules are involved in chromatin organization, DNA repair, cell cycle regulation, and apoptosis and also include RNA polymerase II, some RNA-binding proteins, and some specific Dnmt1-inhibitory RNA molecules. Combined insights from studies of different enzymatic features of Dnmt1 offer novel ideas for development of drug candidates, and can be used in selection of promising drug candidates from more than 15 different compounds that have been identified as possible inhibitors of DNA methylation in cells.
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Affiliation(s)
- Željko M Svedružić
- Medical Biochemistry, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia
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36
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Rengaraj D, Lee BR, Lee SI, Seo HW, Han JY. Expression patterns and miRNA regulation of DNA methyltransferases in chicken primordial germ cells. PLoS One 2011; 6:e19524. [PMID: 21559294 PMCID: PMC3086922 DOI: 10.1371/journal.pone.0019524] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 04/06/2011] [Indexed: 12/21/2022] Open
Abstract
DNA methylation is widespread in most species, from bacteria to mammals, and is crucial for genomic imprinting, gene expression, and embryogenesis. DNA methylation occurs via two major classes of enzymatic reactions: maintenance-type methylation catalyzed by DNA (cytosine-5-)-methyltransferase (DNMT) 1, and de novo methylation catalyzed by DNMT 3 alpha (DNMT3A) and -beta (DNMT3B). The expression pattern and regulation of DNMT genes in primordial germ cells (PGCs) and germ line cells has not been sufficiently established in birds. Therefore, we employed bioinformatics, RT-PCR, real-time PCR, and in situ hybridization analyses to examine the structural conservation and conserved expression patterns of chicken DNMT family genes. We further examined the regulation of a candidate de novo DNA methyltransferase gene, cDNMT3B by cotransfection of cDNMT3B 3'UTR- and cDNMT3B 3'UTR-specific miRNAs through a dual fluorescence reporter assay. All cDNMT family members were differentially detected during early embryonic development. Of interest, cDNMT3B expression was highly detected in early embryos and in PGCs. During germ line development and sexual maturation, cDNMT3B expression was reestablished in a female germ cell-specific manner. In the dual fluorescence reporter assay, cDNMT3B expression was significantly downregulated by four miRNAs: gga-miR-15c (25.82%), gga-miR-29b (30.01%), gga-miR-383 (30.0%), and gga-miR-222 (31.28%). Our data highlight the structural conservation and conserved expression patterns of chicken DNMTs. The miRNAs investigated in this study may induce downregulation of gene expression in chicken PGCs and germ cells.
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Affiliation(s)
- Deivendran Rengaraj
- WCU Biomodulation Major, Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Bo Ram Lee
- WCU Biomodulation Major, Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Sang In Lee
- WCU Biomodulation Major, Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Hee Won Seo
- WCU Biomodulation Major, Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Jae Yong Han
- WCU Biomodulation Major, Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
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37
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Frauer C, Rottach A, Meilinger D, Bultmann S, Fellinger K, Hasenöder S, Wang M, Qin W, Söding J, Spada F, Leonhardt H. Different binding properties and function of CXXC zinc finger domains in Dnmt1 and Tet1. PLoS One 2011; 6:e16627. [PMID: 21311766 PMCID: PMC3032784 DOI: 10.1371/journal.pone.0016627] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 01/05/2011] [Indexed: 01/09/2023] Open
Abstract
Several mammalian proteins involved in chromatin and DNA modification contain CXXC zinc finger domains. We compared the structure and function of the CXXC domains in the DNA methyltransferase Dnmt1 and the methylcytosine dioxygenase Tet1. Sequence alignment showed that both CXXC domains have a very similar framework but differ in the central tip region. Based on the known structure of a similar MLL1 domain we developed homology models and designed expression constructs for the isolated CXXC domains of Dnmt1 and Tet1 accordingly. We show that the CXXC domain of Tet1 has no DNA binding activity and is dispensable for catalytic activity in vivo. In contrast, the CXXC domain of Dnmt1 selectively binds DNA substrates containing unmethylated CpG sites. Surprisingly, a Dnmt1 mutant construct lacking the CXXC domain formed covalent complexes with cytosine bases both in vitro and in vivo and rescued DNA methylation patterns in dnmt1−/− embryonic stem cells (ESCs) just as efficiently as wild type Dnmt1. Interestingly, neither wild type nor ΔCXXC Dnmt1 re-methylated imprinted CpG sites of the H19a promoter in dnmt1−/− ESCs, arguing against a role of the CXXC domain in restraining Dnmt1 methyltransferase activity on unmethylated CpG sites.
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Affiliation(s)
- Carina Frauer
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Andrea Rottach
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Daniela Meilinger
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Sebastian Bultmann
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Karin Fellinger
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Stefan Hasenöder
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Mengxi Wang
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Weihua Qin
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
| | - Johannes Söding
- Gene Center Munich, Ludwig Maximilians University Munich, Munich, Germany.
| | - Fabio Spada
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
- * E-mail: (FS); (HL)
| | - Heinrich Leonhardt
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Planegg, Germany
- * E-mail: (FS); (HL)
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Smith E, Shilatifard A. The chromatin signaling pathway: diverse mechanisms of recruitment of histone-modifying enzymes and varied biological outcomes. Mol Cell 2011; 40:689-701. [PMID: 21145479 DOI: 10.1016/j.molcel.2010.11.031] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/10/2010] [Accepted: 10/07/2010] [Indexed: 12/14/2022]
Abstract
Posttranslational modifications of histones are coupled in the regulation of the cellular processes involving chromatin, such as transcription, replication, repair, and genome stability. Recent biochemical and genetic studies have clearly demonstrated that many aspects of chromatin, in addition to posttranslational modifications of histones, provide surfaces that can interact with effectors and the modifying machineries in a context-dependent manner, all as a part of the "chromatin signaling pathway." Here, we have reviewed recent findings on the molecular basis for the recruitment of the chromatin-modifying machineries and their diverse and varied biological outcomes.
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Affiliation(s)
- Edwin Smith
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
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39
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Le T, Kim KP, Fan G, Faull KF. A sensitive mass spectrometry method for simultaneous quantification of DNA methylation and hydroxymethylation levels in biological samples. Anal Biochem 2011; 412:203-9. [PMID: 21272560 DOI: 10.1016/j.ab.2011.01.026] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/13/2011] [Accepted: 01/19/2011] [Indexed: 01/30/2023]
Abstract
The recent discovery of 5-hydroxymethyl-cytosine (5 hmC) in embryonic stem cells and postmitotic neurons has triggered the need for quantitative measurements of both 5-methyl-cytosine (5 mC) and 5 hmC in the same sample. We have developed a method using liquid chromatography electrospray ionization tandem mass spectrometry with multiple reaction monitoring (LC-ESI-MS/MS-MRM) to simultaneously measure levels of 5 mC and 5 hmC in digested genomic DNA. This method is fast, robust, and accurate, and it is more sensitive than the current 5 hmC quantitation methods such as end labeling with thin layer chromatography and radiolabeling by glycosylation. Only 50 ng of digested genomic DNA is required to measure the presence of 0.1% 5 hmC in DNA from mouse embryonic stem cells. Using this procedure, we show that human induced pluripotent stem cells exhibit a dramatic increase in 5 mC and 5 hmC levels compared with parental fibroblast cells, suggesting a dynamic regulation of DNA methylation and hydroxymethylation during cellular reprogramming.
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Affiliation(s)
- Thuc Le
- Department of Human Genetics, Broad Stem Cell Research Center, David Geffen School of Medicine, University of California - Los Angeles, Los Angeles, CA 90095, USA
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40
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Tsai KW, Hu LY, Wu CW, Li SC, Lai CH, Kao HW, Fang WL, Lin WC. Epigenetic regulation of miR-196b expression in gastric cancer. Genes Chromosomes Cancer 2011; 49:969-80. [PMID: 20662076 DOI: 10.1002/gcc.20804] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
MicroRNAs (miRNAs) are short noncoding RNAs that play important roles in cellular processes and disease pathogenesis via the control of specific targeted gene expression. The miR-196s miRNA is encoded at three paralogous loci in three HOX clusters and acts as an oncogenic miRNA in cancer progression. Recent studies have demonstrated that the expression of miR-196b increases cell proliferation and survival in leukemic cells. Here, we used a sequential methylation analysis to reveal that the methylation status correlated well with miR-196b expression in different cell lines. Treatment with the demethylating drug 5-Aza-dC reactivated miR-196b transcription in methylation-silenced cells. Using in vitro methylation approach, we further provide evidences that promoter hypermethylation represses miR-196b transcriptional activation tightly in human cancer cell lines. We also demonstrate that the expression of miR-196b is significantly elevated in gastric cancer and that hypomethylation status of miR-196b CpG islands frequently is observed in primary gastric tumors. Our results provide important information on miR-196s regulation and demonstrate that abnormal DNA hypomethylation induces overexpression of miR-196b in gastric cancer.
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Affiliation(s)
- Kuo-Wang Tsai
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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Natural history of eukaryotic DNA methylation systems. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 101:25-104. [PMID: 21507349 DOI: 10.1016/b978-0-12-387685-0.00002-0] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Methylation of cytosines and adenines in DNA is a widespread epigenetic mark in both prokaryotes and eukaryotes. In eukaryotes, it has a profound influence on chromatin structure and dynamics. Recent advances in genomics and biochemistry have considerably elucidated the functions and provenance of these DNA modifications. DNA methylases appear to have emerged first in bacterial restriction-modification (R-M) systems from ancient RNA-modifying enzymes, in transitions that involved acquisition of novel catalytic residues and DNA-recognition features. DNA adenine methylases appear to have been acquired by ciliates, heterolobosean amoeboflagellates, and certain chlorophyte algae. Six distinct clades of cytosine methylases, including the DNMT1, DNMT2, and DNMT3 clades, were acquired by eukaryotes through independent lateral transfer of their precursors from bacteria or bacteriophages. In addition to these, multiple adenine and cytosine methylases were acquired by several families of eukaryotic transposons. In eukaryotes, the DNA-methylase module was often combined with distinct modified and unmodified peptide recognition domains and other modules mediating specialized interactions, for example, the RFD module of DNMT1 which contains a permuted Sm domain linked to a helix-turn-helix domain. In eukaryotes, the evolution of DNA methylases appears to have proceeded in parallel to the elaboration of histone-modifying enzymes and the RNAi system, with functions related to counter-viral and counter-transposon defense, and regulation of DNA repair and differential gene expression being their primary ancestral functions. Diverse DNA demethylation systems that utilize base-excision repair via DNA glycosylases and cytosine deaminases appear to have emerged in multiple eukaryotic lineages. Comparative genomics suggests that the link between cytosine methylation and DNA glycosylases probably emerged first in a novel R-M system in bacteria. Recent studies suggest that the 5mC is not a terminal DNA modification, with enzymes of the Tet/JBP family of 2-oxoglutarate- and iron-dependent dioxygenases further hydroxylating it to form 5-hydroxymethylcytosine (5hmC). These enzymes emerged first in bacteriophages and appear to have been transferred to eukaryotes on one or more occasions. Eukaryotes appear to have recruited three major types of DNA-binding domains (SRA/SAD, TAM/MBD, and CXXC) in discriminating DNA with methylated or unmethylated cytosines. Analysis of the domain architectures of these domains and the DNA methylases suggests that early in eukaryotic evolution they developed a close functional link with SET-domain methylases and Jumonji-related demethylases that operate on peptides in chromatin proteins. In several eukaryotes, other functional connections were elaborated in the form of various combinations between domains related to DNA methylation and those involved in ATP-dependent chromatin remodeling and RNAi. In certain eukaryotes, such as mammals and angiosperms, novel dependencies on the DNA methylation system emerged, which resulted in it affecting unexpected aspects of the biology of these organisms such as parent-offspring interactions. In genomic terms, this was reflected in the emergence of new proteins related to methylation, such as Stella. The well-developed methylation systems of certain heteroloboseans, stramenopiles, chlorophytes, and haptophyte indicate that these might be new model systems to explore the relevance of DNA modifications in eukaryotes.
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Nandakumar V, Vaid M, Tollefsbol TO, Katiyar SK. Aberrant DNA hypermethylation patterns lead to transcriptional silencing of tumor suppressor genes in UVB-exposed skin and UVB-induced skin tumors of mice. Carcinogenesis 2010; 32:597-604. [PMID: 21186298 DOI: 10.1093/carcin/bgq282] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Overexposure of the human skin to solar ultraviolet (UV) radiation is the major etiologic factor for development of skin cancers. Here, we report the results of epigenetic modifications in UV-exposed skin and skin tumors in a systematic manner. The skin and tumor samples were collected after chronic exposure of the skin of SKH-1 hairless mice to UVB radiation using a well-established photocarcinogenesis protocol. We found a distinct DNA hypermethylation pattern in the UVB-exposed epidermal skin and UVB-induced skin tumors that was associated with the elevated expression and activity of the DNA methyltransferases (Dnmt) 1, Dnmt3a and Dnmt3b. To explore the role of hypermethylation in skin photocarcinogenesis, we focused on the p16(INK4a) and RASSF1A tumor suppressor genes, which are transcriptionally silenced on methylation. We established that the silencing of these genes in UVB-exposed epidermis and UVB-induced skin tumors is associated with a network of epigenetic modifications, including hypoacetylation of histone H3 and H4 and increased histone deacetylation, as well as recruitment of methyl-binding proteins, including MeCP2 and MBD1, to the methylated CpGs. Higher levels of DNA methylation and DNMT activity in human squamous cell carcinoma specimens than in normal human skin suggest that the data are relevant clinically. Our data indicate for the first time that UVB-induced DNA hypermethylation, enhanced Dnmt activity and histone modifications occur in UVB-exposed skin and UVB-induced skin tumors and suggest that these events are involved in the silencing of tumor suppressor genes and in skin tumor development.
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Affiliation(s)
- Vijayalakshmi Nandakumar
- Department of Dermatology, University of Alabama at Birmingham, Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294, USA
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Jurkowska RZ, Jurkowski TP, Jeltsch A. Structure and function of mammalian DNA methyltransferases. Chembiochem 2010; 12:206-22. [PMID: 21243710 DOI: 10.1002/cbic.201000195] [Citation(s) in RCA: 469] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Indexed: 12/16/2022]
Abstract
DNA methylation plays an important role in epigenetic signalling, having an impact on gene regulation, chromatin structure, development and disease. Here, we review the structures and functions of the mammalian DNA methyltransferases Dnmt1, Dnmt3a and Dnmt3b, including their domain structures, catalytic mechanisms, localisation, regulation, post-translational modifications and interaction with chromatin and other proteins, summarising data obtained in genetic, cell biology and enzymatic studies. We focus on the question of how the molecular and enzymatic properties of these enzymes are connected to the dynamics of DNA methylation patterns and to the roles the enzymes play in the processes of de novo and maintenance DNA methylation. Recent enzymatic and genome-wide methylome data have led to a new model of genomic DNA methylation patterns based on the preservation of average levels of DNA methylation in certain regions, rather than the methylation states of individual CG sites.
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Affiliation(s)
- Renata Zofia Jurkowska
- Biochemistry Laboratory, School of Engineering and Science, Jacobs University, Bremen, Germany
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Juliandi B, Abematsu M, Nakashima K. Epigenetic regulation in neural stem cell differentiation. Dev Growth Differ 2010; 52:493-504. [DOI: 10.1111/j.1440-169x.2010.01175.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Choudhuri S, Cui Y, Klaassen CD. Molecular targets of epigenetic regulation and effectors of environmental influences. Toxicol Appl Pharmacol 2010; 245:378-93. [PMID: 20381512 DOI: 10.1016/j.taap.2010.03.022] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 03/25/2010] [Accepted: 03/29/2010] [Indexed: 12/31/2022]
Abstract
The true understanding of what we currently define as epigenetics evolved over time as our knowledge on DNA methylation and chromatin modifications and their effects on gene expression increased. The current explosion of research on epigenetics and the increasing documentation of the effects of various environmental factors on DNA methylation, chromatin modification, as well as on the expression of small non-coding RNAs (ncRNAs) have expanded the scope of research on the etiology of various diseases including cancer. The current review briefly discusses the molecular mechanisms of epigenetic regulation and expands the discussion with examples on the role of environment, such as the immediate environment during development, in inducing epigenetic changes and modulating gene expression.
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Affiliation(s)
- Supratim Choudhuri
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Additive Safety, Division of Biotechnology and GRAS Notice Review, College Park, MD, USA.
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Clouaire T, de Las Heras JI, Merusi C, Stancheva I. Recruitment of MBD1 to target genes requires sequence-specific interaction of the MBD domain with methylated DNA. Nucleic Acids Res 2010; 38:4620-34. [PMID: 20378711 PMCID: PMC2919722 DOI: 10.1093/nar/gkq228] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
MBD1, a member of the methyl-CpG-binding domain family of proteins, has been reported to repress transcription of methylated and unmethylated promoters. As some MBD1 isoforms contain two DNA-binding domains—an MBD, which recognizes methylated DNA; and a CXXC3 zinc finger, which binds unmethylated CpG—it is unclear whether these two domains function independently of each other or if they cooperate in facilitating recruitment of MBD1 to particular genomic loci. In this report we investigate DNA-binding specificity of MBD and CXXC3 domains in vitro and in vivo. We find that the methyl-CpG-binding domain of MBD1 binds more efficiently to methylated DNA within a specific sequence context. We identify genes that are targeted by MBD1 in human cells and demonstrate that a functional MBD domain is necessary and sufficient for recruitment of MBD1 to specific sites at these loci, while DNA binding by the CXXC3 motif is largely dispensable. In summary, the binding preferences of MBD1, although dependent upon the presence of methylated DNA, are clearly distinct from those of other methyl-CpG-binding proteins, MBD2 and MeCP2.
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Affiliation(s)
- Thomas Clouaire
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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Lan J, Hua S, He X, Zhang Y. DNA methyltransferases and methyl-binding proteins of mammals. Acta Biochim Biophys Sin (Shanghai) 2010; 42:243-52. [PMID: 20383462 DOI: 10.1093/abbs/gmq015] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In mammals, DNA methylation, characterized by the transfer of the methyl group from S-adenosylmethionines to a base (mainly referred to cytosine), acts as a major epigenetic modification. In parallel to DNA sequences arrangement, modification of methylation to DNA sequences has far-reaching influence on biological functions and activities, for it involves controlling gene transcription, regulating chromatin structure, sustaining genome stability and integrity, maintaining parental imprinting and X-chromosome inactivation, suppressing homologous recombination as well as limiting transposable elements, during which DNA methyltransferases (DNMTs) and methyl-binding proteins play important roles. Their aberrance can give rise to dysregulation of gene expression, cell maltransformation and so on. Hence, it is necessary to gain a good understanding of these two important kinds of proteins, which will help to better investigate the epigenetic mechanisms and manipulate the modifications according to our will based on its reversibility. Here we briefly review our current understanding of DNMTs and methyl-binding proteins in mammals.
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Affiliation(s)
- Jie Lan
- Institution of biotechnology, Northwest Sci-Tech University of Agriculture and Forestry, Yangling, China.
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Sakamoto J, Fujiya M, Okamoto K, Nata T, Inaba Y, Moriichi K, Tanabe H, Mizukami Y, Watari J, Ashida T, Kohgo Y. Immunoprecipitation of nucleosomal DNA is a novel procedure to improve the sensitivity of serum screening for the p16 hypermethylation associated with colon cancer. Cancer Epidemiol 2010; 34:194-9. [PMID: 20129840 DOI: 10.1016/j.canep.2010.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 12/27/2009] [Accepted: 01/05/2010] [Indexed: 12/16/2022]
Abstract
BACKGROUND We developed a novel method of methylation-specific PCR (MSP) using immunoprecipitation with anti-histone antibody (IP-MSP) to efficiently detect serum methylated DNA tightly bound to de-acetylated histones. MATERIALS AND METHODS The detection limit of IP-MSP for p16 methylation was determined with a standard made by cell line (SKCO-1) lysate. p16 methylation of tumor and/or serum of 51 colorectal cancers and 10 adenoma patients, and 10 healthy volunteers was detected with conventional MSP or IP-MSP. RESULTS IP-MSP detected p16 methylation from 0.5pg/mul of the cell lysate. The sensitivity of IP-MSP for detecting serum p16 methylation in 27 patients with tumors characterized by p16 methylation was significantly higher than that with conventional method (81% versus 59%), particularly in Stage II patients (91% versus 45%). IP-MSP detected no p16 hypermethylation in sera of adenoma patients and volunteers. CONCLUSIONS IP-MSP is thus considered to be a promising procedure to detect serum methylated DNA in colorectal cancer patients.
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Affiliation(s)
- Jun Sakamoto
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical College, 2-1-1-1, Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510, Japan
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Abstract
Profound changes in the epigenetic landscape of cancer cells underlie the development of human malignancies. These changes include large-scale DNA methylation changes throughout the genome as well as alterations in the compendium of post-translational chromatin modifications. Epigenetic aberrations impact multiple steps during tumorigenesis, ultimately promoting the selection of neoplastic cells with increasing pathogenicity. Identification of these alterations for use as predictive and prognostic biomarkers has been a highly sought after goal. Recent advances in the field have not only greatly expanded our knowledge of the epigenetic changes driving neoplasia but also demonstrated their significant clinical utility as cancer biomarkers. These biomarkers have proved to be useful for identifying patients whose malignancies are sensitive to specific cytotoxic chemotherapies and may hold promise for predicting which patients will benefit from newer targeted agents directed at oncogenes. The recent application of global analysis strategies has further accelerated our understanding of the epigenome and promises to enhance the identification of epigenomic programs underlying cancer progression and treatment response.
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Affiliation(s)
- Timothy A Chan
- Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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