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Noack F, Pataskar A, Schneider M, Buchholz F, Tiwari VK, Calegari F. Assessment and site-specific manipulation of DNA (hydroxy-)methylation during mouse corticogenesis. Life Sci Alliance 2019; 2:2/2/e201900331. [PMID: 30814272 PMCID: PMC6394126 DOI: 10.26508/lsa.201900331] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 12/17/2022] Open
Abstract
This work describes the dynamics of DNA modifications in specific cell types of the developing mammalian cortex. By providing a new method to manipulate this process in vivo, it is shown how this process can influence brain formation. Dynamic changes in DNA (hydroxy-)methylation are fundamental for stem cell differentiation. However, the signature of these epigenetic marks in specific cell types during corticogenesis is unknown. Moreover, site-specific manipulation of cytosine modifications is needed to reveal the significance and function of these changes. Here, we report the first assessment of (hydroxy-)methylation in neural stem cells, neurogenic progenitors, and newborn neurons during mammalian corticogenesis. We found that gain in hydroxymethylation and loss in methylation occur sequentially at specific cellular transitions during neurogenic commitment. We also found that these changes predominantly occur within enhancers of neurogenic genes up-regulated during neurogenesis and target of pioneer transcription factors. We further optimized the use of dCas9-Tet1 manipulation of (hydroxy-)methylation, locus-specifically, in vivo, showing the biological relevance of our observations for Dchs1, a regulator of corticogenesis involved in developmental malformations and cognitive impairment. Together, our data reveal the dynamics of cytosine modifications in lineage-related cell types, whereby methylation is reduced and hydroxymethylation gained during the neurogenic lineage concurrently with up-regulation of pioneer transcription factors and activation of enhancers for neurogenic genes.
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Affiliation(s)
- Florian Noack
- CRTD-Center for Regenerative Therapies, School of Medicine, Technische Universität Dresden, Dresden, Germany
| | | | - Martin Schneider
- Medical Systems Biology, School of Medicine, Technische Universität Dresden and Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Frank Buchholz
- Medical Systems Biology, School of Medicine, Technische Universität Dresden and Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | | | - Federico Calegari
- CRTD-Center for Regenerative Therapies, School of Medicine, Technische Universität Dresden, Dresden, Germany
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The Roles of Human DNA Methyltransferases and Their Isoforms in Shaping the Epigenome. Genes (Basel) 2019; 10:genes10020172. [PMID: 30813436 PMCID: PMC6409524 DOI: 10.3390/genes10020172] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/16/2019] [Accepted: 02/19/2019] [Indexed: 12/20/2022] Open
Abstract
A DNA sequence is the hard copy of the human genome and it is a driving force in determining the physiological processes in an organism. Concurrently, the chemical modification of the genome and its related histone proteins is dynamically involved in regulating physiological processes and diseases, which overall constitutes the epigenome network. Among the various forms of epigenetic modifications, DNA methylation at the C-5 position of cytosine in the cytosine–guanine (CpG) dinucleotide is one of the most well studied epigenetic modifications. DNA methyltransferases (DNMTs) are a family of enzymes involved in generating and maintaining CpG methylation across the genome. In mammalian systems, DNA methylation is performed by DNMT1 and DNMT3s (DNMT3A and 3B). DNMT1 is predominantly involved in the maintenance of DNA methylation during cell division, while DNMT3s are involved in establishing de novo cytosine methylation and maintenance in both embryonic and somatic cells. In general, all DNMTs require accessory proteins, such as ubiquitin-like containing plant homeodomain (PHD) and really interesting new gene (RING) finger domain 1 (UHRF1) or DNMT3-like (DNMT3L), for their biological function. This review mainly focuses on the role of DNMT3B and its isoforms in de novo methylation and maintenance of DNA methylation, especially with respect to their role as an accessory protein.
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Bennett SA, Tanaz R, Cobos SN, Torrente MP. Epigenetics in amyotrophic lateral sclerosis: a role for histone post-translational modifications in neurodegenerative disease. Transl Res 2019; 204:19-30. [PMID: 30391475 PMCID: PMC6331271 DOI: 10.1016/j.trsl.2018.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/26/2018] [Accepted: 10/09/2018] [Indexed: 02/06/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is the third most common adult onset neurodegenerative disorder worldwide. It is generally characterized by progressive paralysis starting at the limbs ultimately leading to death caused by respiratory failure. There is no cure and current treatments fail to slow the progression of the disease. As such, new treatment options are desperately needed. Epigenetic targets are an attractive possibility because they are reversible. Epigenetics refers to heritable changes in gene expression unrelated to changes in DNA sequence. Three main epigenetic mechanisms include the methylation of DNA, microRNAs and the post-translational modification of histone proteins. Histone modifications occur in many amino acid residues and include phosphorylation, acetylation, methylation as well as other chemical moieties. Recent evidence points to a possible role for epigenetic mechanisms in the etiology of ALS. Here, we review recent advances linking ALS and epigenetics, with a strong focus on histone modifications. Both local and global changes in histone modification profiles are associated with ALS drawing attention to potential targets for future diagnostic and treatment approaches.
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Affiliation(s)
- Seth A Bennett
- Department of Chemistry, Brooklyn College, Brooklyn, NewYork; Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York
| | - Royena Tanaz
- Department of Chemistry, Brooklyn College, Brooklyn, NewYork
| | - Samantha N Cobos
- Department of Chemistry, Brooklyn College, Brooklyn, NewYork; Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016
| | - Mariana P Torrente
- Department of Chemistry, Brooklyn College, Brooklyn, NewYork; Ph.D. Programs in Chemistry, Biochemistry, and Biology, The Graduate Center of the City University of New York, New York, New York.
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54
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Saunders J, Hore Z, Gentry C, McMahon S, Denk F. Negative Evidence for a Functional Role of Neuronal DNMT3a in Persistent Pain. Front Mol Neurosci 2018; 11:332. [PMID: 30258352 PMCID: PMC6143791 DOI: 10.3389/fnmol.2018.00332] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/27/2018] [Indexed: 11/13/2022] Open
Abstract
Traditionally, neuroscience has had to rely on mixed tissue analysis to examine transcriptional and epigenetic changes in the context of nervous system function or pathology. However, particularly when studying chronic pain conditions, this approach can be flawed, since it neglects to take into account the shifting contribution of different cell types across experimental conditions. Here, we demonstrate this using the example of DNA methyltransferases (DNMTs) – a group of epigenetic modifiers consisting of Dnmt1, Dnmt3a, and Dnmt3b in mammalian cells. We used sensory neuron-specific knockout mice for Dnmt3a/3b as well as pharmacological blockade of Dnmt1 to study their role in nociception. In contrast to previous analyses on whole tissue, we find that Dnmt3a and 3b protein is not expressed in adult DRG neurons, that none of the DNA methyltransferases are regulated with injury and that interfering with their function has no effect on nociception. Our results therefore currently do not support a role for neuronal DNA methyltransferases in pain processing in adult animals.
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Affiliation(s)
- Jessica Saunders
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Zoe Hore
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Clive Gentry
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Stephen McMahon
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Franziska Denk
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
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Corso-Díaz X, Jaeger C, Chaitankar V, Swaroop A. Epigenetic control of gene regulation during development and disease: A view from the retina. Prog Retin Eye Res 2018; 65:1-27. [PMID: 29544768 PMCID: PMC6054546 DOI: 10.1016/j.preteyeres.2018.03.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 02/01/2018] [Accepted: 03/08/2018] [Indexed: 12/20/2022]
Abstract
Complex biological processes, such as organogenesis and homeostasis, are stringently regulated by genetic programs that are fine-tuned by epigenetic factors to establish cell fates and/or to respond to the microenvironment. Gene regulatory networks that guide cell differentiation and function are modulated and stabilized by modifications to DNA, RNA and proteins. In this review, we focus on two key epigenetic changes - DNA methylation and histone modifications - and discuss their contribution to retinal development, aging and disease, especially in the context of age-related macular degeneration (AMD) and diabetic retinopathy. We highlight less-studied roles of DNA methylation and provide the RNA expression profiles of epigenetic enzymes in human and mouse retina in comparison to other tissues. We also review computational tools and emergent technologies to profile, analyze and integrate epigenetic information. We suggest implementation of editing tools and single-cell technologies to trace and perturb the epigenome for delineating its role in transcriptional regulation. Finally, we present our thoughts on exciting avenues for exploring epigenome in retinal metabolism, disease modeling, and regeneration.
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Affiliation(s)
- Ximena Corso-Díaz
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Catherine Jaeger
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Vijender Chaitankar
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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Xu T, Wang C, Shen J, Tong P, O’Keefe R. Ablation of Dnmt3b in chondrocytes suppresses cell maturation during embryonic development. J Cell Biochem 2018; 119:5852-5863. [PMID: 29637597 PMCID: PMC5993586 DOI: 10.1002/jcb.26775] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/31/2018] [Indexed: 12/18/2022]
Abstract
DNA methylation is a major mode of epigenetic regulation in the mammalian genome and is essential for embryonic development. The three catalytic DNA methyltransferases (Dnmts), Dnmt1, Dnmt3a, and Dnmt3b, catalyze the methylation of cytosine. Dnmt3b is highly expressed in chondrocytes and global knockout of Dnmt3b led to skeletal deformations and embryonic lethality, suggesting an essential role of Dnmt3b in endochondral bone formation. To further define the role of Dnmt3b in skeletal development, Dnmt3b was deleted in Col2 positive chondrocyte lineage cells. Both axial and appendicular skeletal size were reduced and bone mineralization was delayed in Col2Cre+ ;Dnmt3bf/f (Dnmt3bCol2 ) mice at E14.5 and E18.5. While Alcian Blue Hematoxylin/Orange G (ABH/OG) staining showed normal chondrocyte columns in control growth plates, the length of hypertrophic chondrocyte zone and type X collagen expression were decreased in E18.5 growth plates from Dnmt3bCol2 mice. TUNEL and PCNA staining demonstrated that the delay in chondrocyte maturation observed in the Dnmt3bCol2 growth plates was not secondary to altered chondrocyte apoptosis or proliferation. Complementary in vitro experiments were performed on primary sternal chondrocytes isolated from control and Dnmt3bCol2 mice. Gene expression studies confirmed delayed terminal maturation as Mmp13 and Col10a1 expression was down-regulated in Dnmt3bCol2 chondrocytes. In addition, alkaline phosphatase (ALP) and Alizarin Red staining confirmed that Dnmt3b deletion in chondrocytes delays in vitro chondrocyte hypertrophic differentiation and matrix mineralization. Mechanistically, Dnmt3b gene deletion resulted in decreased BMP signaling through reduction of Smad1 phosphorylation. These findings show that epigenetic factor, Dnmt3b is necessary for normal chondrocyte hypertrophic maturation and limb development.
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Affiliation(s)
- Taotao Xu
- Department of Orthopaedic Surgery, School of Medicine, Washington University, St. Louis, MO 63110
- Institute of Orthopaedics and Traumatology, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310053, China
- Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Cuicui Wang
- Department of Orthopaedic Surgery, School of Medicine, Washington University, St. Louis, MO 63110
| | - Jie Shen
- Department of Orthopaedic Surgery, School of Medicine, Washington University, St. Louis, MO 63110
| | - Peijian Tong
- Institute of Orthopaedics and Traumatology, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310053, China
- Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Regis O’Keefe
- Department of Orthopaedic Surgery, School of Medicine, Washington University, St. Louis, MO 63110
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57
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Jia L, Chopp M, Wang L, Lu X, Szalad A, Zhang ZG. Exosomes derived from high-glucose-stimulated Schwann cells promote development of diabetic peripheral neuropathy. FASEB J 2018; 32:fj201800597R. [PMID: 29932869 PMCID: PMC6219828 DOI: 10.1096/fj.201800597r] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 06/12/2018] [Indexed: 02/07/2023]
Abstract
Schwann cells actively interact with axons of dorsal root ganglia (DRG) neurons. Exosomes mediate intercellular communication by transferring their biomaterials, including microRNAs (miRs) into recipient cells. We hypothesized that exosomes derived from Schwann cells stimulated by high glucose (HG) exosomes accelerate development of diabetic peripheral neuropathy and that exosomal cargo miRs contribute to this process. We found that HG exosomes contained high levels of miR-28, -31a, and -130a compared to exosomes derived from non-HG-stimulated Schwann cells. In vitro, treatment of distal axons with HG exosomes resulted in reduction of axonal growth, which was associated with elevation of miR-28, -31a, and -130a and reduction of their target proteins of DNA methyltransferase-3α, NUMB (an endocytic adaptor protein), synaptosome associated protein 25, and growth-associated protein-43 in axons. In vivo, administration of HG exosomes to sciatic nerves of diabetic db/db mice at 7 wk of age promoted occurrence of peripheral neuropathy characterized by impairment of nerve conduction velocity and induction of mechanic and thermal hypoesthesia, which was associated with substantial decreases in intraepidermal nerve fibers. Our findings demonstrate a functional role of exosomes derived from HG-stimulated Schwann cells in mediating development of diabetic peripheral neuropathy.-Jia, L., Chopp, M., Wang, L., Lu, X., Szalad, A., Zhang, Z. G. Exosomes derived from high-glucose-stimulated Schwann cells promote development of diabetic peripheral neuropathy.
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Affiliation(s)
- Longfei Jia
- Inovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA; and
- Department of Physics, Oakland University, Rochester, Michigan, USA
| | - Lei Wang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Xuerong Lu
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Alexandra Szalad
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA; and
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Wang CX, Cui GS, Liu X, Xu K, Wang M, Zhang XX, Jiang LY, Li A, Yang Y, Lai WY, Sun BF, Jiang GB, Wang HL, Tong WM, Li W, Wang XJ, Yang YG, Zhou Q. METTL3-mediated m6A modification is required for cerebellar development. PLoS Biol 2018; 16:e2004880. [PMID: 29879109 PMCID: PMC6021109 DOI: 10.1371/journal.pbio.2004880] [Citation(s) in RCA: 189] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 06/27/2018] [Accepted: 05/15/2018] [Indexed: 01/26/2023] Open
Abstract
N6-methyladenosine (m6A) RNA methylation is the most abundant modification on mRNAs and plays important roles in various biological processes. The formation of m6A is catalyzed by a methyltransferase complex including methyltransferase-like 3 (METTL3) as a key factor. However, the in vivo functions of METTL3 and m6A modification in mammalian development remain unclear. Here, we show that specific inactivation of Mettl3 in mouse nervous system causes severe developmental defects in the brain. Mettl3 conditional knockout (cKO) mice manifest cerebellar hypoplasia caused by drastically enhanced apoptosis of newborn cerebellar granule cells (CGCs) in the external granular layer (EGL). METTL3 depletion–induced loss of m6A modification causes extended RNA half-lives and aberrant splicing events, consequently leading to dysregulation of transcriptome-wide gene expression and premature CGC death. Our findings reveal a critical role of METTL3-mediated m6A in regulating the development of mammalian cerebellum. N6-methyladenosine (m6A) is an abundant modification in mRNA molecules and regulates mRNA metabolism and various biological processes, such as cell fate control, early embryonic development, sex determination, and diseases like diabetes and obesity. Adenosine methylation is regulated by a large methyltransferase complex and by demethylases, as well as by other binding proteins. METTL3 is one of the core subunits of the methyltransferase complex catalyzing m6A formation. However, the role of METTL3-mediated m6A in mammalian brain development remains unclear mainly because of the lack of specific spatiotemporal knockout animal models, as conventional METTL3 knockout in mice leads to early embryonic death. In this study, we specifically inactivated METTL3 in the developing mouse brain. We detected a drastic depletion of m6A accompanied by severe developmental defects in the cerebellum of these mice. Further analysis established that METTL3-mediated m6A participates in cerebellar development by controlling mRNA stability of genes related to cerebellar development and apoptosis and by regulating alternative splicing of pre-mRNAs of synapse-associated genes.
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Affiliation(s)
- Chen-Xin Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guan-Shen Cui
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, China
| | - Xiuying Liu
- Key Laboratory of Genetic Network Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Kai Xu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Meng Wang
- Key Laboratory of Genetic Network Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xin-Xin Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Li-Yuan Jiang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Ang Li
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Ying Yang
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Wei-Yi Lai
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Bao-Fa Sun
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Gui-Bin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Hai-Lin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Wei-Min Tong
- Department of Pathology, Center for Experimental Animal Research, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Xiu-Jie Wang
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Genetic Network Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XJW); (YGY); (QZ)
| | - Yun-Gui Yang
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XJW); (YGY); (QZ)
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XJW); (YGY); (QZ)
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Geist J, Ward CW, Kontrogianni-Konstantopoulos A. Structure before function: myosin binding protein-C slow is a structural protein with regulatory properties. FASEB J 2018; 32:fj201800624R. [PMID: 29874125 PMCID: PMC6219831 DOI: 10.1096/fj.201800624r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/14/2018] [Indexed: 01/12/2023]
Abstract
Myosin binding protein-C slow (sMyBP-C) comprises a family of accessory proteins in skeletal muscles that bind both myosin and actin filaments. Herein, we examined the role of sMyBP-C in adult skeletal muscles using in vivo gene transfer and clustered regularly interspaced short palindromic repeats technology to knock down all known sMyBP-C variants. Our findings, confirmed in two different skeletal muscles, demonstrated efficient knockdown (KD) of sMyBP-C (>70%) resulting in notably decreased levels of thick, but not thin, filament proteins ranging from ∼50% for slow and fast myosin to ∼20% for myomesin. Consistent with this, A bands were selectively distorted, and sarcomere length was significantly reduced. Contrary to earlier in vitro studies showing that addition of recombinant sMyBP-C slows down the formation of actomyosin crossbridges, our work demonstrates that KD of sMyBP-C in intact myofibers results in decreased contraction and relaxation kinetics under no-load conditions. Similarly, KD muscles develop markedly reduced twitch and tetanic force and contraction velocity. Taken together, our results show that sMyBP-C is essential for the regular organization and maintenance of myosin filaments into A bands and that its structural role precedes its ability to regulate actomyosin crossbridges.-Geist, J., Ward, C. W., Kontrogianni-Konstantopoulos, A. Structure before function: myosin binding protein-C slow is a structural protein with regulatory properties.
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Affiliation(s)
- Janelle Geist
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Christopher W. Ward
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
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60
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Ziller MJ, Ortega JA, Quinlan KA, Santos DP, Gu H, Martin EJ, Galonska C, Pop R, Maidl S, Di Pardo A, Huang M, Meltzer HY, Gnirke A, Heckman CJ, Meissner A, Kiskinis E. Dissecting the Functional Consequences of De Novo DNA Methylation Dynamics in Human Motor Neuron Differentiation and Physiology. Cell Stem Cell 2018; 22:559-574.e9. [PMID: 29551301 DOI: 10.1016/j.stem.2018.02.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 12/18/2017] [Accepted: 02/23/2018] [Indexed: 01/10/2023]
Abstract
The somatic DNA methylation (DNAme) landscape is established early in development but remains highly dynamic within focal regions that overlap with gene regulatory elements. The significance of these dynamic changes, particularly in the central nervous system, remains unresolved. Here, we utilize a powerful human embryonic stem cell differentiation model for the generation of motor neurons (MNs) in combination with genetic mutations in the de novo DNAme machinery. We quantitatively dissect the role of DNAme in directing somatic cell fate with high-resolution genome-wide bisulfite-, bulk-, and single-cell-RNA sequencing. We find defects in neuralization and MN differentiation in DNMT3A knockouts (KO) that can be rescued by the targeting of DNAme to key developmental loci using catalytically inactive dCas9. We also find decreased dendritic arborization and altered electrophysiological properties in DNMT3A KO MNs. Our work provides a list of DNMT3A-regulated targets and a mechanistic link between de novo DNAme, cellular differentiation, and human MN function.
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Affiliation(s)
- Michael J Ziller
- Department of Translational Psychiatry, Max Planck Institute of Psychiatry, Munich 80804, Germany
| | - Juan A Ortega
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Katharina A Quinlan
- Department of Biomedical and Pharmaceutical Sciences, George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
| | - David P Santos
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Hongcang Gu
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Eric J Martin
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Christina Galonska
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin 14195, Germany
| | - Ramona Pop
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Susanne Maidl
- Department of Translational Psychiatry, Max Planck Institute of Psychiatry, Munich 80804, Germany
| | - Alba Di Pardo
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Mei Huang
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Herbert Y Meltzer
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Andreas Gnirke
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - C J Heckman
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Alexander Meissner
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin 14195, Germany; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
| | - Evangelos Kiskinis
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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61
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Sokpor G, Abbas E, Rosenbusch J, Staiger JF, Tuoc T. Transcriptional and Epigenetic Control of Mammalian Olfactory Epithelium Development. Mol Neurobiol 2018. [PMID: 29532253 DOI: 10.1007/s12035-018-0987-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The postnatal mammalian olfactory epithelium (OE) represents a major aspect of the peripheral olfactory system. It is a pseudostratified tissue that originates from the olfactory placode and is composed of diverse cells, some of which are specialized receptor neurons capable of transducing odorant stimuli to afford the perception of smell (olfaction). The OE is known to offer a tractable miniature model for studying the systematic generation of neurons and glia that typify neural tissue development. During OE development, stem/progenitor cells that will become olfactory sensory neurons and/or non-neuronal cell types display fine spatiotemporal expression of neuronal and non-neuronal genes that ensures their proper proliferation, differentiation, survival, and regeneration. Many factors, including transcription and epigenetic factors, have been identified as key regulators of the expression of such requisite genes to permit normal OE morphogenesis. Typically, specific interactive regulatory networks established between transcription and epigenetic factors/cofactors orchestrate histogenesis in the embryonic and adult OE. Hence, investigation of these regulatory networks critical for OE development promises to disclose strategies that may be employed in manipulating the stepwise transition of olfactory precursor cells to become fully differentiated and functional neuronal and non-neuronal cell types. Such strategies potentially offer formidable means of replacing injured or degenerated neural cells as therapeutics for nervous system perturbations. This review recapitulates the developmental cellular diversity of the olfactory neuroepithelium and discusses findings on how the precise and cooperative molecular control by transcriptional and epigenetic machinery is indispensable for OE ontogeny.
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Affiliation(s)
- Godwin Sokpor
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany
| | - Eman Abbas
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany.,Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Joachim Rosenbusch
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany
| | - Jochen F Staiger
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075, Goettingen, Germany
| | - Tran Tuoc
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany. .,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075, Goettingen, Germany.
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62
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Base-Resolution Analysis of DNA Methylation Patterns Downstream of Dnmt3a in Mouse Naïve B Cells. G3-GENES GENOMES GENETICS 2018; 8:805-813. [PMID: 29326230 PMCID: PMC5844302 DOI: 10.1534/g3.117.300446] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The DNA methyltransferase, Dnmt3a, is dynamically regulated throughout mammalian B cell development and upon activation by antigenic stimulation. Dnmt3a inactivation in hematopoietic stem cells has been shown to drive B cell-related malignancies, including chronic lymphocytic leukemia, and associates with specific DNA methylation patterns in transformed cells. However, while it is clear that inactivation of Dnmt3a in hematopoietic stem cells has profound functional effects, the consequences of Dnmt3a inactivation in cells of the B lineage are unclear. To assess whether loss of Dnmt3a at the earliest stages of B cell development lead to DNA methylation defects that might impair function, we selectively inactivated Dnmt3a early in mouse B cell development and then utilized whole genome bisulfite sequencing to generate base-resolution profiles of Dnmt3a+/+ and Dnmt3a−/− naïve splenic B cells. Overall, we find that global methylation patterns are largely consistent between Dnmt3a+/+ and Dnmt3a−/− naïve B cells, indicating a minimal functional effect of DNMT3A in mature B cells. However, loss of Dnmt3a induced 449 focal DNA methylation changes, dominated by loss-of-methylation events. Regions found to be hypomethylated in Dnmt3a−/− naïve splenic B cells were enriched in gene bodies of transcripts expressed in B cells, a fraction of which are implicated in B cell-related disease. Overall, the results from this study suggest that factors other than Dnmt3a are the major drivers for methylome maintenance in B cell development.
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63
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Du X, Tian M, Wang X, Zhang J, Huang Q, Liu L, Shen H. Cortex and hippocampus DNA epigenetic response to a long-term arsenic exposure via drinking water. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 234:590-600. [PMID: 29223816 DOI: 10.1016/j.envpol.2017.11.083] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/03/2017] [Accepted: 11/25/2017] [Indexed: 05/25/2023]
Abstract
The neurotoxicity of arsenic is a serious health problem, especially for children. DNA epigenetic change may be an important pathogenic mechanism, but the molecular pathway remains obscure. In this study, the weaned male Sprague-Dawly (SD) rats were treated with arsenic trioxide via drinking water for 6 months, simulating real developmental exposure situation of children. Arsenic exposure impaired the cognitive abilities, and altered the expression of neuronal activity-regulated genes. Total arsenic concentrations of cortex and hippocampus tissues were significantly increased in a dose-dependent manner. The reduction in 5-methylcytosine (5 mC) and 5-hydroxymethylcytosine (5hmC) levels as well as the down-regulation of DNA methyltransferases (DNMTs) and ten-eleven translocations (TETs) expression suggested that DNA methylation/demethylation processes were significantly suppressed in brain tissues. S-adenosylmethionine (SAM) level wasn't changed, but the expression of the important indicators of oxidative/anti-oxidative balance and tricarboxylic acid (TCA) cycle was significantly deregulated. Overall, arsenic can disrupt oxidative/anti-oxidative balance, further inhibit TETs expression through TCA cycle and alpha-ketoglutarate (α-KG) pathway, and consequently cause DNA methylation/demethylation disruption. The present study implies oxidative stress but not SAM depletion may lead to DNA epigenetic alteration and arsenic neurotoxicity.
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Affiliation(s)
- Xiaoyan Du
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China; University of Chinese Academy of Sciences, China
| | - Meiping Tian
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China; University of Chinese Academy of Sciences, China
| | - Xiaoxue Wang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China
| | - Jie Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China; Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, China.
| | - Qingyu Huang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China
| | - Liangpo Liu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China
| | - Heqing Shen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China.
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64
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Stricker SH, Götz M. DNA-Methylation: Master or Slave of Neural Fate Decisions? Front Neurosci 2018; 12:5. [PMID: 29449798 PMCID: PMC5799221 DOI: 10.3389/fnins.2018.00005] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/04/2018] [Indexed: 01/05/2023] Open
Abstract
The pristine formation of complex organs depends on sharp temporal and spatial control of gene expression. Therefore, epigenetic mechanisms have been frequently attributed a central role in controlling cell fate determination. A prime example for this is the first discovered and still most studied epigenetic mark, DNA methylation, and the development of the most complex mammalian organ, the brain. Recently, the field of epigenetics has advanced significantly: new DNA modifications were discovered, epigenomic profiling became widely accessible, and methods for targeted epigenomic manipulation have been developed. Thus, it is time to challenge established models of epigenetic gene regulation. Here, we review the current state of knowledge about DNA modifications, their epigenomic distribution, and their regulatory role. We will summarize the evidence suggesting they possess crucial roles in neurogenesis and discuss whether this likely includes lineage choice regulation or rather effects on differentiation. Finally, we will attempt an outlook on how questions, which remain unresolved, could be answered soon.
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Affiliation(s)
- Stefan H Stricker
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universität, Munich, Germany.,Physiological Genomics, BioMedical Center, Munich, Germany.,German Research Center for Environmental Health, Ingolstädter Landstrasse 1, Germany and Biomedical Center, Institute of Stem Cell Research, Helmholtz Zentrum, Ludwig-Maximilian-Universität, Munich, Germany
| | - Magdalena Götz
- Physiological Genomics, BioMedical Center, Munich, Germany.,German Research Center for Environmental Health, Ingolstädter Landstrasse 1, Germany and Biomedical Center, Institute of Stem Cell Research, Helmholtz Zentrum, Ludwig-Maximilian-Universität, Munich, Germany.,German Excellence Cluster of Systems Neurology, Munich, Germany
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65
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Boule LA, Burke CG, Jin GB, Lawrence BP. Aryl hydrocarbon receptor signaling modulates antiviral immune responses: ligand metabolism rather than chemical source is the stronger predictor of outcome. Sci Rep 2018; 8:1826. [PMID: 29379138 PMCID: PMC5789012 DOI: 10.1038/s41598-018-20197-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/11/2018] [Indexed: 12/20/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) offers a compelling target to modulate the immune system. AHR agonists alter adaptive immune responses, but the consequences differ across studies. We report here the comparison of four agents representing different sources of AHR ligands in mice infected with influenza A virus (IAV): TCDD, prototype exogenous AHR agonist; PCB126, pollutant with documented human exposure; ITE, novel pharmaceutical; and FICZ, degradation product of tryptophan. All four compounds diminished virus-specific IgM levels and increased the proportion of regulatory T cells. TCDD, PCB126 and ITE, but not FICZ, reduced virus-specific IgG levels and CD8+ T cell responses. Similarly, ITE, PCB126, and TCDD reduced Th1 and Tfh cells, whereas FICZ increased their frequency. In Cyp1a1-deficient mice, all compounds, including FICZ, reduced the response to IAV. Conditional Ahr knockout mice revealed that all four compounds require AHR within hematopoietic cells. Thus, differences in the immune response to IAV likely reflect variances in quality, magnitude, and duration of AHR signaling. This indicates that binding affinity and metabolism may be stronger predictors of immune effects than a compound’s source of origin, and that harnessing AHR will require finding a balance between dampening immune-mediated pathologies and maintaining sufficient host defenses against infection.
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Affiliation(s)
- Lisbeth A Boule
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,CBR International, Boulder, CO, USA
| | - Catherine G Burke
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Guang-Bi Jin
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Department of Preventative Medicine, School of Medicine, Yaniban University, Yanji City, Jilin Provence, China
| | - B Paige Lawrence
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA. .,Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
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66
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Xie H, Zhao S, Liu S. Aging of Human Adult Stem Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1086:105-115. [PMID: 30232755 DOI: 10.1007/978-981-13-1117-8_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the continuous development of stem cell research in recent years, it is realized that stem cell aging may be the core issue of organ aging. As an important approach and main content of regenerative medicine, the stem cell research brings great hope to overcome difficult diseases and improve the quality of life for human beings and become the key to solve this issue. Based on this research, the varying characteristics of stem cells in aging could be recognized; the role of stem cells in the organ aging and regeneration will be revealed; the function of stem cells will be controllable and regulatable in tissues and organs; the stem cells from tissues and organs with rapid or slow cell renewal (e.g., liver and neuron) could be continuously observed from the levels of cellular molecules and dynamic complex. With the assistance of systematical research approaches, the function and mechanism studies can be conducted via multi-perspectives and levels during the different stages of organ aging and regeneration. All of the abovementioned requires great efforts to thoroughly understand the basic rule and the way of stem cell regulation in organ aging and regeneration. Final to the end, the dream of antiaging, efficient repair, and organ remodeling could be realized and also can meet the major needs of population health and disease treatment in our country, meaningfully to contribute benefits for the health of human beings.
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Affiliation(s)
- Han Xie
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shouliang Zhao
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shangfeng Liu
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China.
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67
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Gao J, Cahill CM, Huang X, Roffman JL, Lamon-Fava S, Fava M, Mischoulon D, Rogers JT. S-Adenosyl Methionine and Transmethylation Pathways in Neuropsychiatric Diseases Throughout Life. Neurotherapeutics 2018; 15:156-175. [PMID: 29340929 PMCID: PMC5794704 DOI: 10.1007/s13311-017-0593-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
S-Adenosyl methionine (SAMe), as a major methyl donor, exerts its influence on central nervous system function through cellular transmethylation pathways, including the methylation of DNA, histones, protein phosphatase 2A, and several catecholamine moieties. Based on available evidence, this review focuses on the lifelong range of severe neuropsychiatric and neurodegenerative diseases and their associated neuropathologies, which have been linked to the deficiency/load of SAMe production or/and the disturbance in transmethylation pathways. Also included in this review are the present-day applications of SAMe in the treatment in these diseases in each age group.
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Affiliation(s)
- Jin Gao
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Clinical Psychology, Qilu Hospital of Shandong University, Qingdao, Shandong Province, China
| | - Catherine M Cahill
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Xudong Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Joshua L Roffman
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Stefania Lamon-Fava
- Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA
| | - Maurizio Fava
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - David Mischoulon
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jack T Rogers
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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68
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Abstract
The role of DNA methylation in brain development is an intense area of research because the brain has particularly high levels of CpG and mutations in many of the proteins involved in the establishment, maintenance, interpretation, and removal of DNA methylation impact brain development and/or function. These include DNA methyltransferase (DNMT), Ten-Eleven Translocation (TET), and Methyl-CpG binding proteins (MBPs). Recent advances in sequencing breadth and depth as well the detection of different forms of methylation have greatly expanded our understanding of the diversity of DNA methylation in the brain. The contributions of DNA methylation and associated proteins to embryonic and adult neurogenesis will be examined. Particular attention will be given to the impact on adult hippocampal neurogenesis (AHN), which is a key mechanism contributing to brain plasticity, learning, memory and mood regulation. DNA methylation influences multiple aspects of neurogenesis from stem cell maintenance and proliferation, fate specification, neuronal differentiation and maturation, and synaptogenesis. In addition, DNA methylation during neurogenesis has been shown to be responsive to many extrinsic signals, both under normal conditions and during disease and injury. Finally, crosstalk between DNA methylation, Methyl-DNA binding domain (MBD) proteins such as MeCP2 and MBD1 and histone modifying complexes is used as an example to illustrate the extensive interconnection between these epigenetic regulatory systems.
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Affiliation(s)
- Emily M Jobe
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Xinyu Zhao
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI, USA.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
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69
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You D, Nilsson E, Tenen DE, Lyubetskaya A, Lo JC, Jiang R, Deng J, Dawes BA, Vaag A, Ling C, Rosen ED, Kang S. Dnmt3a is an epigenetic mediator of adipose insulin resistance. eLife 2017; 6:30766. [PMID: 29091029 PMCID: PMC5730374 DOI: 10.7554/elife.30766] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/29/2017] [Indexed: 12/21/2022] Open
Abstract
Insulin resistance results from an intricate interaction between genetic make-up and environment, and thus may be orchestrated by epigenetic mechanisms like DNA methylation. Here, we demonstrate that DNA methyltransferase 3a (Dnmt3a) is both necessary and sufficient to mediate insulin resistance in cultured mouse and human adipocytes. Furthermore, adipose-specific Dnmt3a knock-out mice are protected from diet-induced insulin resistance and glucose intolerance without accompanying changes in adiposity. Unbiased gene profiling studies revealed Fgf21 as a key negatively regulated Dnmt3a target gene in adipocytes with concordant changes in DNA methylation at the Fgf21 promoter region. Consistent with this, Fgf21 can rescue Dnmt3a-mediated insulin resistance, and DNA methylation at the FGF21 locus was elevated in human subjects with diabetes and correlated negatively with expression of FGF21 in human adipose tissue. Taken together, our data demonstrate that adipose Dnmt3a is a novel epigenetic mediator of insulin resistance in vitro and in vivo.
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Affiliation(s)
- Dongjoo You
- Nutritional Sciences and Toxicology Department, University of California, Berkeley, Berkeley, United States
| | - Emma Nilsson
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Danielle E Tenen
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Boston, United States
| | | | - James C Lo
- Weill Cornell Medical College, New York, United States
| | - Rencong Jiang
- Nutritional Sciences and Toxicology Department, University of California, Berkeley, Berkeley, United States
| | - Jasmine Deng
- Nutritional Sciences and Toxicology Department, University of California, Berkeley, Berkeley, United States
| | - Brian A Dawes
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Boston, United States
| | - Allan Vaag
- Diabetes and Metabolism, Department of Endocrinology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Early Clinical Development, AstraZeneca, Innovative Medicines, Göteborg, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Evan D Rosen
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Boston, United States.,Broad Institute of Harvard and MIT, Cambridge, United States
| | - Sona Kang
- Nutritional Sciences and Toxicology Department, University of California, Berkeley, Berkeley, United States
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70
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Stroud H, Su SC, Hrvatin S, Greben AW, Renthal W, Boxer LD, Nagy MA, Hochbaum DR, Kinde B, Gabel HW, Greenberg ME. Early-Life Gene Expression in Neurons Modulates Lasting Epigenetic States. Cell 2017; 171:1151-1164.e16. [PMID: 29056337 DOI: 10.1016/j.cell.2017.09.047] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 07/17/2017] [Accepted: 09/25/2017] [Indexed: 12/20/2022]
Abstract
In mammals, the environment plays a critical role in promoting the final steps in neuronal development during the early postnatal period. While epigenetic factors are thought to contribute to this process, the underlying molecular mechanisms remain poorly understood. Here, we show that in the brain during early life, the DNA methyltransferase DNMT3A transiently binds across transcribed regions of lowly expressed genes, and its binding specifies the pattern of DNA methylation at CA sequences (mCA) within these genes. We find that DNMT3A occupancy and mCA deposition within the transcribed regions of genes is negatively regulated by gene transcription and may be modified by early-life experience. Once deposited, mCA is bound by the methyl-DNA-binding protein MECP2 and functions in a rheostat-like manner to fine-tune the cell-type-specific transcription of genes that are critical for brain function.
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Affiliation(s)
- Hume Stroud
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Susan C Su
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sinisa Hrvatin
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Alexander W Greben
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - William Renthal
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Lisa D Boxer
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - M Aurel Nagy
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Daniel R Hochbaum
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Benyam Kinde
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Harrison W Gabel
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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71
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Tian Z, Zhao Q, Biswas S, Deng W. Methods of reactivation and reprogramming of neural stem cells for neural repair. Methods 2017; 133:3-20. [PMID: 28864354 DOI: 10.1016/j.ymeth.2017.08.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/21/2017] [Accepted: 08/24/2017] [Indexed: 12/27/2022] Open
Abstract
Research on the biology of adult neural stem cells (NSCs) and induced NSCs (iNSCs), as well as NSC-based therapies for diseases in central nervous system (CNS) has started to generate the expectation that these cells may be used for treatments in CNS injuries or disorders. Recent technological progresses in both NSCs themselves and their derivatives have brought us closer to therapeutic applications. Adult neurogenesis presents in particular regions in mammal brain, known as neurogenic niches such as the dental gyrus (DG) in hippocampus and the subventricular zone (SVZ), within which adult NSCs usually stay for long periods out of the cell cycle, in G0. The reactivation of quiescent adult NSCs needs orchestrated interactions between the extrinsic stimulis from niches and the intrinsic factors involving transcription factors (TFs), signaling pathway, epigenetics, and metabolism to start an intracellular regulatory program, which promotes the quiescent NSCs exit G0 and reenter cell cycle. Extrinsic and intrinsic mechanisms that regulate adult NSCs are interconnected and feedback on one another. Since endogenous neurogenesis only happens in restricted regions and steadily fails with disease advances, interest has evolved to apply the iNSCs converted from somatic cells to treat CNS disorders, as is also promising and preferable. To overcome the limitation of viral-based reprogramming of iNSCs, bioactive small molecules (SM) have been explored to enhance the efficiency of iNSC reprogramming or even replace TFs, making the iNSCs more amenable to clinical application. Despite intense research efforts to translate the studies of adult and induced NSCs from the bench to bedside, vital troubles remain at several steps in these processes. In this review, we examine the present status, advancement, pitfalls, and potential of the two types of NSC technologies, focusing on each aspects of reactivation of quiescent adult NSC and reprogramming of iNSC from somatic cells, as well as on progresses in cell-based regenerative strategies for neural repair and criteria for successful therapeutic applications.
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Affiliation(s)
- Zuojun Tian
- Department of Neurology, The Institute of Guangzhou Respiratory Disease, State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, PR China; Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Sacramento, CA 95817, USA
| | - Qiuge Zhao
- Department of Neurology, The Institute of Guangzhou Respiratory Disease, State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, PR China
| | - Sangita Biswas
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Sacramento, CA 95817, USA.
| | - Wenbin Deng
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95817, USA; Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Sacramento, CA 95817, USA.
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72
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Singh RK, Mallela RK, Hayes A, Dunham NR, Hedden ME, Enke RA, Fariss RN, Sternberg H, West MD, Nasonkin IO. Dnmt1, Dnmt3a and Dnmt3b cooperate in photoreceptor and outer plexiform layer development in the mammalian retina. Exp Eye Res 2017; 159:132-146. [PMID: 27865785 DOI: 10.1016/j.exer.2016.11.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 10/21/2016] [Accepted: 11/14/2016] [Indexed: 11/18/2022]
Abstract
Characterizing the role of epigenetic regulation in the mammalian retina is critical for understanding fundamental mechanisms of retinal development and disease. DNA methylation, an epigenetic modifier of genomic DNA, plays an important role in modulating networks of tissue and cell-specific gene expression. However, the impact of DNA methylation on retinal development and homeostasis of retinal neurons remains unclear. Here, we have created a tissue-specific DNA methyltransferase (Dnmt) triple mutant mouse in an effort to characterize the impact of DNA methylation on retinal development and homeostasis. An Rx-Cre transgene was used to drive targeted mutation of all three murine Dnmt genes in the mouse retina encoding major DNA methylation enzymes DNMT1, DNMT3A and DNMT3B. The triple mutant mice represent a hypomorph model since Dnmt1 catalytic activity was still present and excision of Dnmt3a and Dnmt3b had only about 90% efficiency. Mutation of all three Dnmts resulted in global genomic hypomethylation and dramatic reorganization of the photoreceptor and synaptic layers within retina. Transcriptome and proteomic analyses demonstrated enrichment of dysregulated phototransduction and synaptic genes. The 5 mC signal in triple mutant retina was confined to the central heterochromatin but reduced in the peripheral heterochromatin region of photoreceptor nuclei. In addition, we found a reduction of the 5 mC signal in ganglion cell nuclei. Collectively, this data suggests cooperation of all three Dnmts in the formation and homeostasis of photoreceptors and other retinal neurons within the mammalian retina, and highlight the relevance of epigenetic regulation to sensory retinal disorders and vision loss.
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Affiliation(s)
- Ratnesh K Singh
- Department of Ophthalmology, University of Pittsburgh Medical School, USA.
| | - Ramya K Mallela
- Department of Ophthalmology, University of Pittsburgh Medical School, USA
| | - Abigail Hayes
- Department of Ophthalmology, West Virginia University, USA
| | | | | | - Raymond A Enke
- Department of Biology, James Madison University, USA; Center for Genome and Metagenome Studies, James Madison University, USA
| | - Robert N Fariss
- Biological Imaging Core, National Eye Institute, Bethesda, MD 20892, USA
| | - Hal Sternberg
- BioTime, 1010 Atlantic Avenue, Alameda, CA 94501, USA
| | | | - Igor O Nasonkin
- Department of Ophthalmology, University of Pittsburgh Medical School, USA.
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73
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Herbeck YE, Khantemirova AR, Antonov EV, Goncharova NI, Gulevich RG, Shepeleva DV, Trut LN. Expression of the DNA methyltransferase genes in silver foxes experimentally selected for domestication. RUSS J GENET+ 2017. [DOI: 10.1134/s1022795417040056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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74
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Bayraktar G, Kreutz MR. Neuronal DNA Methyltransferases: Epigenetic Mediators between Synaptic Activity and Gene Expression? Neuroscientist 2017; 24:171-185. [PMID: 28513272 PMCID: PMC5846851 DOI: 10.1177/1073858417707457] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
DNMT3A and 3B are the main de novo DNA methyltransferases (DNMTs) in the brain that introduce new methylation marks to non-methylated DNA in postmitotic neurons. DNA methylation is a key epigenetic mark that is known to regulate important cellular processes in neuronal development and brain plasticity. Accumulating evidence disclosed rapid and dynamic changes in DNA methylation of plasticity-relevant genes that are important for learning and memory formation. To understand how DNMTs contribute to brain function and how they are regulated by neuronal activity is a prerequisite for a deeper appreciation of activity-dependent gene expression in health and disease. This review discusses the functional role of de novo methyltransferases and in particular DNMT3A1 in the adult brain with special emphasis on synaptic plasticity, memory formation, and brain disorders.
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Affiliation(s)
- Gonca Bayraktar
- 1 RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Michael R Kreutz
- 1 RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.,2 Leibniz Group "Dendritic Organelles and Synaptic Function", ZMNH, Magdeburg, Germany
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The Crucial Role of DNA Methylation and MeCP2 in Neuronal Function. Genes (Basel) 2017; 8:genes8050141. [PMID: 28505093 PMCID: PMC5448015 DOI: 10.3390/genes8050141] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/25/2017] [Accepted: 05/05/2017] [Indexed: 12/16/2022] Open
Abstract
A neuron is unique in its ability to dynamically modify its transcriptional output in response to synaptic activity while maintaining a core gene expression program that preserves cellular identity throughout a lifetime that is longer than almost every other cell type in the body. A contributing factor to the immense adaptability of a neuron is its unique epigenetic landscape that elicits locus-specific alterations in chromatin architecture, which in turn influences gene expression. One such epigenetic modification that is sensitive to changes in synaptic activity, as well as essential for maintaining cellular identity, is DNA methylation. The focus of this article is on the importance of DNA methylation in neuronal function, summarizing recent studies on critical players in the establishment of (the “writing”), the modification or erasure of (the “editing”), and the mediation of (the “reading”) DNA methylation in neurodevelopment and neuroplasticity. One “reader” of DNA methylation in particular, methyl-CpG-binding protein 2 (MeCP2), is highlighted, given its undisputed importance in neuronal function.
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76
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Hoang TV, Horowitz ER, Chaffee BR, Qi P, Flake RE, Bruney DG, Rasor BJ, Rosalez SE, Wagner BD, Robinson ML. Lens development requires DNMT1 but takes place normally in the absence of both DNMT3A and DNMT3B activity. Epigenetics 2017; 12:27-40. [PMID: 27824296 PMCID: PMC5270636 DOI: 10.1080/15592294.2016.1253651] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/14/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022] Open
Abstract
Despite the wealth of knowledge of transcription factors involved in lens development, little information exists about the role of DNA methylation in this process. Here, we investigated the role of DNA methylation in lens development and fiber cell differentiation using mice conditionally lacking maintenance or de novo methyltransferases in the lens lineage. We found that while Dnmt1 inactivation at the lens placode stage (via the Le-Cre transgene) led to lens DNA hypomethylation and severe lens epithelial apoptosis, lens fiber cell differentiation remained largely unaffected. The simultaneous deletion of phosphatase and tensin homolog (Pten) elevated the level of phosphorylated AKT and rescued many of the morphological defects and cell death in DNMT1-deficient lenses. With a different Cre driver (MLR10) we demonstrated that a small number of lens epithelial cells escaped Dnmt1-deletion and over-proliferated to compensate for the loss of Dnmt1-deleted cells, suggesting that lens epithelium possess a substantial capacity for self-renewal. Unlike lenses deficient for Dnmt1, inactivation of both Dnmt3a and Dnmt3b by either the Le-Cre or MLR10-Cre transgene did not result in any obvious lens phenotype prior to 10 months of age. Taken together, while lens epithelial cell survival requires DNMT1, morphologically normal lenses develop in the absence of both DNMT3A and DNMT3B.
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Affiliation(s)
- Thanh V. Hoang
- Department of Biology, Miami University, Oxford, OH, USA
| | | | | | - Peipei Qi
- Department of Biology, Miami University, Oxford, OH, USA
| | | | | | - Blake J. Rasor
- Department of Biology, Miami University, Oxford, OH, USA
| | | | - Brad D. Wagner
- Department of Biology, Miami University, Oxford, OH, USA
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77
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DNA methylation in the gene body influences MeCP2-mediated gene repression. Proc Natl Acad Sci U S A 2016; 113:15114-15119. [PMID: 27965390 DOI: 10.1073/pnas.1618737114] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rett syndrome is a severe neurodevelopmental disorder caused by mutations in the methyl-CpG binding protein gene (MECP2). MeCP2 is a methyl-cytosine binding protein that is proposed to function as a transcriptional repressor. However, multiple gene expression studies comparing wild-type and MeCP2-deficient neurons have failed to identify gene expression changes consistent with loss of a classical transcriptional repressor. Recent work suggests that one function of MeCP2 in neurons is to temper the expression of the longest genes in the genome by binding to methylated CA dinucleotides (mCA) within transcribed regions of these genes. Here we explore the mechanism of mCA and MeCP2 in fine tuning the expression of long genes. We find that mCA is not only highly enriched within the body of genes normally repressed by MeCP2, but also enriched within extended megabase-scale regions surrounding MeCP2-repressed genes. Whereas enrichment of mCA exists in a broad region around these genes, mCA together with mCG within gene bodies appears to be the primary driver of gene repression by MeCP2. Disruption of methylation at CA sites within the brain results in depletion of MeCP2 across genes that normally contain a high density of gene-body mCA. We further find that the degree of gene repression by MeCP2 is proportional to the total number of methylated cytosine MeCP2 binding sites across the body of a gene. These findings suggest a model in which MeCP2 tunes gene expression in neurons by binding within the transcribed regions of genes to impede the elongation of RNA polymerase.
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78
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Kyono Y, Sachs LM, Bilesimo P, Wen L, Denver RJ. Developmental and Thyroid Hormone Regulation of the DNA Methyltransferase 3a Gene in Xenopus Tadpoles. Endocrinology 2016; 157:4961-4972. [PMID: 27779916 PMCID: PMC5133355 DOI: 10.1210/en.2016-1465] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/21/2016] [Indexed: 11/19/2022]
Abstract
Thyroid hormone is essential for normal development in vertebrates. In amphibians, T3 controls metamorphosis by inducing tissue-specific gene regulation programs. A hallmark of T3 action is the modification of chromatin structure, which underlies changes in gene transcription. We found that mRNA for the de novo DNA methyltransferase (DNMT) dnmt3a, but not dnmt1, increased in the brain of Xenopus tadpoles during metamorphosis in parallel with plasma [T3]. Addition of T3 to the rearing water caused a time-dependent increase in dnmt3a mRNA in tadpole brain, tail, and hind limb. By analyzing data from a genome-wide analysis of T3 receptor (TR) binding in tadpole tail, we identified several putative T3 response elements (TREs) within the dnmt3a locus. Using in vitro DNA binding, transient transfection-reporter, and chromatin immunoprecipitation assays for TRs, we identified two functional TREs at -7.1 kb and +5.1 kb relative to the dnmt3a transcription start site. Sequence alignment showed that these TREs are conserved between two related frog species, X. laevis and X. tropicalis, but not with amniotes. Our previous findings showed that this gene is directly regulated by liganded TRs in mouse brain, and whereas the two mouse TREs are conserved among Eutherian mammals, they are not conserved in Xenopus species. Thus, although T3 regulation of dnmt3a may be an ancient pathway in vertebrates, the genomic sites responsible for hormone regulation may have diverged or arisen by convergent evolution. We hypothesize that direct T3 regulation of dnmt3a may be an important mechanism for modulating global changes in DNA methylation.
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Affiliation(s)
- Yasuhiro Kyono
- Neuroscience Graduate Program (Y.K.), The University of Michigan, Ann Arbor, Michigan 48109-1048; UMR-7221, Centre National de la Recherche Scientifique (L.M.S., P.B.), Muséum National d'Histoire Naturelle, 75005 Paris, France; and Department of Molecular, Cellular, and Developmental Biology (L.W., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Laurent M Sachs
- Neuroscience Graduate Program (Y.K.), The University of Michigan, Ann Arbor, Michigan 48109-1048; UMR-7221, Centre National de la Recherche Scientifique (L.M.S., P.B.), Muséum National d'Histoire Naturelle, 75005 Paris, France; and Department of Molecular, Cellular, and Developmental Biology (L.W., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Patrice Bilesimo
- Neuroscience Graduate Program (Y.K.), The University of Michigan, Ann Arbor, Michigan 48109-1048; UMR-7221, Centre National de la Recherche Scientifique (L.M.S., P.B.), Muséum National d'Histoire Naturelle, 75005 Paris, France; and Department of Molecular, Cellular, and Developmental Biology (L.W., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Luan Wen
- Neuroscience Graduate Program (Y.K.), The University of Michigan, Ann Arbor, Michigan 48109-1048; UMR-7221, Centre National de la Recherche Scientifique (L.M.S., P.B.), Muséum National d'Histoire Naturelle, 75005 Paris, France; and Department of Molecular, Cellular, and Developmental Biology (L.W., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Robert J Denver
- Neuroscience Graduate Program (Y.K.), The University of Michigan, Ann Arbor, Michigan 48109-1048; UMR-7221, Centre National de la Recherche Scientifique (L.M.S., P.B.), Muséum National d'Histoire Naturelle, 75005 Paris, France; and Department of Molecular, Cellular, and Developmental Biology (L.W., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109-1048
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79
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DNMT3A mutations promote anthracycline resistance in acute myeloid leukemia via impaired nucleosome remodeling. Nat Med 2016; 22:1488-1495. [PMID: 27841873 PMCID: PMC5359771 DOI: 10.1038/nm.4210] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 09/16/2016] [Indexed: 01/16/2023]
Abstract
Although the majority of patients with acute myeloid leukemia (AML) initially respond to chemotherapy, many of them subsequently relapse, and the mechanistic basis for AML persistence following chemotherapy has not been determined. Recurrent somatic mutations in DNA methyltransferase 3A (DNMT3A), most frequently at arginine 882 (DNMT3AR882), have been observed in AML and in individuals with clonal hematopoiesis in the absence of leukemic transformation. Patients with DNMT3AR882 AML have an inferior outcome when treated with standard-dose daunorubicin-based induction chemotherapy, suggesting that DNMT3AR882 cells persist and drive relapse. We found that Dnmt3a mutations induced hematopoietic stem cell expansion, cooperated with mutations in the FMS-like tyrosine kinase 3 gene (Flt3ITD) and the nucleophosmin gene (Npm1c) to induce AML in vivo, and promoted resistance to anthracycline chemotherapy. In patients with AML, the presence of DNMT3AR882 mutations predicts minimal residual disease, underscoring their role in AML chemoresistance. DNMT3AR882 cells showed impaired nucleosome eviction and chromatin remodeling in response to anthracycline treatment, which resulted from attenuated recruitment of histone chaperone SPT-16 following anthracycline exposure. This defect led to an inability to sense and repair DNA torsional stress, which resulted in increased mutagenesis. Our findings identify a crucial role for DNMT3AR882 mutations in driving AML chemoresistance and highlight the importance of chromatin remodeling in response to cytotoxic chemotherapy.
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80
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Kyono Y, Subramani A, Ramadoss P, Hollenberg AN, Bonett RM, Denver RJ. Liganded Thyroid Hormone Receptors Transactivate the DNA Methyltransferase 3a Gene in Mouse Neuronal Cells. Endocrinology 2016; 157:3647-57. [PMID: 27387481 PMCID: PMC5007891 DOI: 10.1210/en.2015-1529] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 07/01/2016] [Indexed: 12/11/2022]
Abstract
Thyroid hormone (T3) is essential for proper neurological development. The hormone, bound to its receptors, regulates gene transcription in part by modulating posttranslational modifications of histones. Methylation of DNA, which is established by the de novo DNA methyltransferase (DNMT)3a and DNMT3b, and maintained by DNMT1 is another epigenetic modification influencing gene transcription. The expression of Dnmt3a, but not other Dnmt genes, increases in mouse brain in parallel with the postnatal rise in plasma [T3]. We found that treatment of the mouse neuroblastoma cell line Neuro2a[TRβ1] with T3 caused rapid induction of Dnmt3a mRNA, which was resistant to protein synthesis inhibition, supporting that it is a direct T3-response gene. Injection of T3 into postnatal day 6 mice increased Dnmt3a mRNA in the brain by 1 hour. Analysis of two chromatin immunoprecipitation-sequencing datasets, and targeted analyses using chromatin immunoprecipitation, transfection-reporter assays, and in vitro DNA binding identified 2 functional T3-response elements (TREs) at the mouse Dnmt3a locus located +30.3 and +49.3 kb from the transcription start site. Thyroid hormone receptors associated with both of these regions in mouse brain chromatin, but with only 1 (+30.3 kb) in Neuro2a[TRβ1] cells. Deletion of the +30.3-kb TRE using CRISPR/Cas9 genome editing eliminated or strongly reduced the Dnmt3a mRNA response to T3. Bioinformatics analysis showed that both TREs are highly conserved among eutherian mammals. Thyroid regulation of Dnmt3a may be an evolutionarily conserved mechanism for modulating global changes in DNA methylation during postnatal neurological development.
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Affiliation(s)
- Yasuhiro Kyono
- Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104
| | - Arasakumar Subramani
- Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104
| | - Preeti Ramadoss
- Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104
| | - Anthony N Hollenberg
- Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104
| | - Ronald M Bonett
- Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104
| | - Robert J Denver
- Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104
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81
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Subbanna S, Nagre NN, Shivakumar M, Basavarajappa BS. A single day of 5-azacytidine exposure during development induces neurodegeneration in neonatal mice and neurobehavioral deficits in adult mice. Physiol Behav 2016; 167:16-27. [PMID: 27594097 DOI: 10.1016/j.physbeh.2016.08.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/30/2016] [Accepted: 08/31/2016] [Indexed: 12/13/2022]
Abstract
The present study was undertaken to evaluate the immediate and long-term effects of a single-day exposure to 5-Azacytidine (5-AzaC), a DNA methyltransferase inhibitor, on neurobehavioral abnormalities in mice. Our findings suggest that the 5-AzaC treatment significantly inhibited DNA methylation, impaired extracellular signal-regulated kinase (ERK1/2) activation and reduced expression of the activity-regulated cytoskeleton-associated protein (Arc). These events lead to the activation of caspase-3 (a marker for neurodegeneration) in several brain regions, including the hippocampus and cortex, two brain areas that are essential for memory formation and memory storage, respectively. 5-AzaC treatment of P7 mice induced significant deficits in spatial memory, social recognition, and object memory in adult mice and deficits in long-term potentiation (LTP) in adult hippocampal slices. Together, these data demonstrate that the inhibition of DNA methylation by 5-AzaC treatment in P7 mice causes neurodegeneration and impairs ERK1/2 activation and Arc protein expression in neonatal mice and induces behavioral abnormalities in adult mice. DNA methylation-mediated mechanisms appear to be necessary for the proper maturation of synaptic circuits during development, and disruption of this process by 5-AzaC could lead to abnormal cognitive function.
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Affiliation(s)
- Shivakumar Subbanna
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Nagaraja N Nagre
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Madhu Shivakumar
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Balapal S Basavarajappa
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Department of Psychiatry, College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA.
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82
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Dnmt3a Regulates Proliferation of Muscle Satellite Cells via p57Kip2. PLoS Genet 2016; 12:e1006167. [PMID: 27415617 PMCID: PMC4944932 DOI: 10.1371/journal.pgen.1006167] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/13/2016] [Indexed: 11/18/2022] Open
Abstract
Cell differentiation status is defined by the gene expression profile, which is coordinately controlled by epigenetic mechanisms. Cell type-specific DNA methylation patterns are established by chromatin modifiers including de novo DNA methyltransferases, such as Dnmt3a and Dnmt3b. Since the discovery of the myogenic master gene MyoD, myogenic differentiation has been utilized as a model system to study tissue differentiation. Although knowledge about myogenic gene networks is accumulating, there is only a limited understanding of how DNA methylation controls the myogenic gene program. With an aim to elucidate the role of DNA methylation in muscle development and regeneration, we investigate the consequences of mutating Dnmt3a in muscle precursor cells in mice. Pax3 promoter-driven Dnmt3a-conditional knockout (cKO) mice exhibit decreased organ mass in the skeletal muscles, and attenuated regeneration after cardiotoxin-induced muscle injury. In addition, Dnmt3a-null satellite cells (SCs) exhibit a striking loss of proliferation in culture. Transcriptome analysis reveals dysregulated expression of p57Kip2, a member of the Cip/Kip family of cyclin-dependent kinase inhibitors (CDKIs), in the Dnmt3a-KO SCs. Moreover, RNAi-mediated depletion of p57Kip2 replenishes the proliferation activity of the SCs, thus establishing a role for the Dnmt3a-p57Kip2 axis in the regulation of SC proliferation. Consistent with these findings, Dnmt3a-cKO muscles exhibit fewer Pax7+ SCs, which show increased expression of p57Kip2 protein. Thus, Dnmt3a is found to maintain muscle homeostasis by epigenetically regulating the proliferation of SCs through p57Kip2. How muscle homeostasis is maintained is not completely elucidated yet. Epigenetic disorders such as Beckwith-Wiedemann syndrome, which causes hypergrowth of skeletal muscles and rhabdomyosarcoma, indicate that epigenetic regulations such as DNA methylation, contribute to this homeostasis control. DNA methylation is mediated by DNA methyltransferases, such as Dnmt3a and Dnmt3b, which are de novo DNA methyltransferases. The role of DNA methylation in somatic stem cells is not completely understood, although it has been shown to be indispensable in differentiation of primordial germ cells and embryonic stem cells. In this report, we investigated the role of Dnmt3a in muscle satellite cells by analyzing Dnmt3a-conditional knockout (cKO) mice in which Dnmt3a loci are deleted utilizing Cre-recombinase driven by Pax7 or Pax3 promoters that are specifically activated in the muscle precursor lineage. The loss of Dnmt3a in cKO mice causes decreased muscle mass and significantly impaired muscle regeneration. Moreover, Dnmt3a loss also results in a striking loss of proliferation of SCs, which is caused by mis-expression of a cyclin-dependent kinase inhibitor, p57Kip2. Therefore, our findings suggest that DNA methylation plays an essential role in muscle homeostasis.
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83
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Yao B, Christian KM, He C, Jin P, Ming GL, Song H. Epigenetic mechanisms in neurogenesis. Nat Rev Neurosci 2016; 17:537-49. [PMID: 27334043 DOI: 10.1038/nrn.2016.70] [Citation(s) in RCA: 260] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the embryonic and adult brain, neural stem cells proliferate and give rise to neurons and glia through highly regulated processes. Epigenetic mechanisms - including DNA and histone modifications, as well as regulation by non-coding RNAs - have pivotal roles in different stages of neurogenesis. Aberrant epigenetic regulation also contributes to the pathogenesis of various brain disorders. Here, we review recent advances in our understanding of epigenetic regulation in neurogenesis and its dysregulation in brain disorders, including discussion of newly identified DNA cytosine modifications. We also briefly cover the emerging field of epitranscriptomics, which involves modifications of mRNAs and long non-coding RNAs.
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Affiliation(s)
- Bing Yao
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - Kimberly M Christian
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
| | - Chuan He
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - Guo-Li Ming
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
| | - Hongjun Song
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
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84
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Guryanova OA, Lieu YK, Garrett-Bakelman FE, Spitzer B, Glass JL, Shank K, Valencia Martinez AB, Rivera SA, Durham BH, Rapaport F, Keller MD, Pandey S, Bastian L, Tovbin D, Weinstein AR, Teruya-Feldstein J, Abdel-Wahab O, Santini V, Mason CE, Melnick AM, Mukherjee S, Levine RL. Dnmt3a regulates myeloproliferation and liver-specific expansion of hematopoietic stem and progenitor cells. Leukemia 2016; 30:1133-42. [PMID: 26710888 PMCID: PMC4856586 DOI: 10.1038/leu.2015.358] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 12/08/2015] [Accepted: 12/14/2015] [Indexed: 12/22/2022]
Abstract
DNA methyltransferase 3A (DNMT3A) mutations are observed in myeloid malignancies, including myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Transplantation studies have elucidated an important role for Dnmt3a in stem cell self-renewal and in myeloid differentiation. Here, we investigated the impact of conditional hematopoietic Dnmt3a loss on disease phenotype in primary mice. Mx1-Cre-mediated Dnmt3a ablation led to the development of a lethal, fully penetrant MPN with myelodysplasia (MDS/MPN) characterized by peripheral cytopenias and by marked, progressive hepatomegaly. We detected expanded stem/progenitor populations in the liver of Dnmt3a-ablated mice. The MDS/MPN induced by Dnmt3a ablation was transplantable, including the marked hepatomegaly. Homing studies showed that Dnmt3a-deleted bone marrow cells preferentially migrated to the liver. Gene expression and DNA methylation analyses of progenitor cell populations identified differential regulation of hematopoietic regulatory pathways, including fetal liver hematopoiesis transcriptional programs. These data demonstrate that Dnmt3a ablation in the hematopoietic system leads to myeloid transformation in vivo, with cell-autonomous aberrant tissue tropism and marked extramedullary hematopoiesis (EMH) with liver involvement. Hence, in addition to the established role of Dnmt3a in regulating self-renewal, Dnmt3a regulates tissue tropism and limits myeloid progenitor expansion in vivo.
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Affiliation(s)
- Olga A. Guryanova
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Yen K. Lieu
- Department of Medicine and Irving Cancer Research Center, Columbia University, New York, NY
| | | | - Barbara Spitzer
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Jacob L. Glass
- Department of Medicine, Weill Cornell Medical College, New York, NY
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Kaitlyn Shank
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | | | - Sharon A. Rivera
- Department of Medicine and Irving Cancer Research Center, Columbia University, New York, NY
| | - Benjamin H. Durham
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Franck Rapaport
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Matthew D. Keller
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Suveg Pandey
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Lennart Bastian
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Daniel Tovbin
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Abby R. Weinstein
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Julie Teruya-Feldstein
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
| | | | - Christopher E. Mason
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY
| | - Ari M. Melnick
- Department of Medicine, Weill Cornell Medical College, New York, NY
| | - Siddhartha Mukherjee
- Department of Medicine and Irving Cancer Research Center, Columbia University, New York, NY
| | - Ross L. Levine
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
- Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center, New York, NY
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85
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Haney SL, Upchurch GM, Opavska J, Klinkebiel D, Hlady RA, Suresh A, Pirruccello SJ, Shukla V, Lu R, Costinean S, Rizzino A, Karpf AR, Joshi S, Swanson P, Opavsky R. Promoter Hypomethylation and Expression Is Conserved in Mouse Chronic Lymphocytic Leukemia Induced by Decreased or Inactivated Dnmt3a. Cell Rep 2016; 15:1190-201. [PMID: 27134162 DOI: 10.1016/j.celrep.2016.04.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 02/18/2016] [Accepted: 03/28/2016] [Indexed: 01/06/2023] Open
Abstract
DNA methyltransferase 3a (DNMT3A) catalyzes the formation of 5-methyl-cytosine in mammalian genomic DNA, and it is frequently mutated in human hematologic malignancies. Bi-allelic loss of Dnmt3a in mice results in leukemia and lymphoma, including chronic lymphocytic leukemia (CLL). Here, we investigate whether mono-allelic loss of Dnmt3a is sufficient to induce disease. We show that, by 16 months of age, 65% of Dnmt3a(+/-) mice develop a CLL-like disease, and 15% of mice develop non-malignant myeloproliferation. Genome-wide methylation analysis reveals that reduced Dnmt3a levels induce promoter hypomethylation at similar loci in Dnmt3a(+/-) and Dnmt3a(Δ/Δ) CLL, suggesting that promoters are particularly sensitive to Dnmt3a levels. Gene expression analysis identified 26 hypomethylated and overexpressed genes common to both Dnmt3a(+/-) and Dnmt3a(Δ/Δ) CLL as putative oncogenic drivers. Our data provide evidence that Dnmt3a is a haplo-insufficient tumor suppressor in CLL and highlights the importance of deregulated molecular events in disease pathogenesis.
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Affiliation(s)
- Staci L Haney
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - G Michael Upchurch
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Jana Opavska
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - David Klinkebiel
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Ryan A Hlady
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Abhinav Suresh
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Samuel J Pirruccello
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA; Center for Leukemia and Lymphoma Research, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Vipul Shukla
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Runqing Lu
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Stefan Costinean
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Angie Rizzino
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Adam R Karpf
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Shantaram Joshi
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA; Center for Leukemia and Lymphoma Research, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Patrick Swanson
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE 68102, USA
| | - Rene Opavsky
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA; Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA; Center for Leukemia and Lymphoma Research, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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86
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Kennedy BE, Hundert AS, Goguen D, Weaver ICG, Karten B. Presymptomatic Alterations in Amino Acid Metabolism and DNA Methylation in the Cerebellum of a Murine Model of Niemann-Pick Type C Disease. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:1582-97. [PMID: 27083515 DOI: 10.1016/j.ajpath.2016.02.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/08/2016] [Accepted: 02/16/2016] [Indexed: 10/21/2022]
Abstract
The fatal neurodegenerative disorder Niemann-Pick type C (NPC) is caused in most cases by mutations in NPC1, which encodes the late endosomal NPC1 protein. Loss of NPC1 disrupts cholesterol trafficking from late endosomes to the endoplasmic reticulum and plasma membrane, causing cholesterol accumulation in late endosomes/lysosomes. Neurons are particularly vulnerable to this cholesterol trafficking defect, but the pathogenic mechanisms through which NPC1 deficiency causes neuronal dysfunction remain largely unknown. Herein, we have investigated amino acid metabolism in cerebella of NPC1-deficient mice at different stages of NPC disease. Imbalances in amino acid metabolism were evident from increased branched chain amino acid and asparagine levels and altered expression of key enzymes of glutamine/glutamate metabolism in presymptomatic and early symptomatic NPC1-deficient cerebellum. Increased levels of several amino acid intermediates of one-carbon metabolism indicated disturbances in folate and methylation pathways. Alterations in DNA methylation were apparent in decreased expression of DNA methyltransferase 3a and methyl-5'-cytosine-phosphodiester-guanine-domain binding proteins, reduced 5-methylcytosine immunoreactivity in the molecular and Purkinje cell layers, demethylation of genome-wide repetitive LINE-1 elements, and hypermethylation in specific promoter regions of single-copy genes in NPC1-deficient cerebellum at early stages of the disease. Alterations in amino acid metabolism and epigenetic changes in the cerebellum at presymptomatic stages of NPC disease represent previously unrecognized mechanisms of NPC pathogenesis.
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Affiliation(s)
- Barry E Kennedy
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Amos S Hundert
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Donna Goguen
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ian C G Weaver
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
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87
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Abstract
Neurogenesis is not limited to the embryonic stage, but continually proceeds in the adult brain throughout life. Epigenetic mechanisms, including DNA methylation, histone modification and noncoding RNA, play important roles in neurogenesis. For decades, DNA methylation was thought to be a stable modification, except for demethylation in the early embryo. In recent years, DNA methylation has proved to be dynamic during development. In this review, we summarize the latest understanding about DNA methylation dynamics in neurogenesis, including the roles of different methylation forms (5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine), as well as their 'writers', 'readers' and interactions with histone modifications.
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Affiliation(s)
- Zhiqin Wang
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Yuquan He
- Department of Cardiology, The Third Affiliated Hospital of Jilin University, Jilin University, Changchun, Jilin, PR China
| | - Peng Jin
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
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88
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Effects of DNA methylation inhibitors and conventional antidepressants on mice behaviour and brain DNA methylation levels. Acta Neuropsychiatr 2016; 28:11-22. [PMID: 26112212 DOI: 10.1017/neu.2015.40] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Stress increases DNA methylation and decreases the expression of genes involved in neural plasticity, while treatment with DNA methyltransferase inhibitors (DNMTi) increases gene expression and induces antidepressant-like effects in preclinical models. Therefore, the aim of the present work was to further investigate the potential antidepressant-like effect induced by DNMTi by evaluating the behavioural effects induced by associating DNMTi treatment with conventional antidepressant drugs in mice submitted to the forced swimming test (FST). In addition, brain levels of DNA methylation were also investigated. METHODS Mice received systemic injections of 5-aza-2'-deoxycytidine (5-AzaD, 0.1, 0.2 mg/kg), RG108 (0.1, 0.2, 0.4 mg/kg), desipramine (DES, 2.5, 5, 10 mg/kg) or fluoxetine (FLX, 5, 10, 20, 30 mg/kg) and were submitted to the FST or to the open field test (OFT). Additional groups received a combination of subeffective doses of 5-AzaD or RG108 (DNMTi) with subeffective doses of DES or FLX (antidepressants). RESULTS Subeffective doses of RG108 (0.1 mg/kg) or 5-AzaD (0.1 mg/kg) in association with subeffective doses of DES (2.5 mg/kg) or FLX (10 mg/kg) induced significant antidepressant-like effects. Effective doses of RG108 (0.2 mg/kg), 5-AzaD (0.2 mg/kg), DES (10 mg/kg) and FLX (20 mg/kg) atenuated stress-induced changes in DNA methylation levels in the hippocampus and prefrontal cortex. None of the treatments induced locomotor effects in the OFT. CONCLUSION These results suggest that DNMTi potentiate the behavioural effects of antidepressant drugs in the FST and that antidepressants, as well as DNMTi, are able to modulate stress-induced changes in DNA methylation in brain regions closely associated with the neurobiology of depression.
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89
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Akahori H, Guindon S, Yoshizaki S, Muto Y. Molecular Evolution of the TET Gene Family in Mammals. Int J Mol Sci 2015; 16:28472-85. [PMID: 26633372 PMCID: PMC4691057 DOI: 10.3390/ijms161226110] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/10/2015] [Accepted: 11/18/2015] [Indexed: 11/21/2022] Open
Abstract
Ten-eleven translocation (TET) proteins, a family of Fe2+- and 2-oxoglutarate-dependent dioxygenases, are involved in DNA demethylation. They also help regulate various cellular functions. Three TET paralogs have been identified (TET1, TET2, and TET3) in humans. This study focuses on the evolution of mammalian TET genes. Distinct patterns in TET1 and TET2 vs. TET3 were revealed by codon-based tests of positive selection. Results indicate that TET1 and TET2 genes have experienced positive selection more frequently than TET3 gene, and that the majority of codon sites evolved under strong negative selection. These findings imply that the selective pressure on TET3 may have been relaxed in several lineages during the course of evolution. Our analysis of convergent amino acid substitutions also supports the different evolutionary dynamics among TET gene subfamily members. All of the five amino acid sites that are inferred to have evolved under positive selection in the catalytic domain of TET2 are localized at the protein’s outer surface. The adaptive changes of these positively selected amino acid sites could be associated with dynamic interactions between other TET-interacting proteins, and positive selection thus appears to shift the regulatory scheme of TET enzyme function.
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Affiliation(s)
- Hiromichi Akahori
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan.
| | - Stéphane Guindon
- Department of Statistics, the University of Auckland, Auckland 1010, New Zealand.
| | - Sumio Yoshizaki
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan.
| | - Yoshinori Muto
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan.
- Department of Functional Bioscience, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193, Japan.
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90
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Emery B, Lu QR. Transcriptional and Epigenetic Regulation of Oligodendrocyte Development and Myelination in the Central Nervous System. Cold Spring Harb Perspect Biol 2015; 7:a020461. [PMID: 26134004 DOI: 10.1101/cshperspect.a020461] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Central nervous system (CNS) myelination by oligodendrocytes (OLs) is a highly orchestrated process involving well-defined steps from specification of neural stem cells into proliferative OL precursors followed by terminal differentiation and subsequent maturation of these precursors into myelinating OLs. These specification and differentiation processes are mediated by profound global changes in gene expression, which are in turn subject to control by both extracellular signals and regulatory networks intrinsic to the OL lineage. Recently, basic transcriptional mechanisms that control OL differentiation and myelination have begun to be elucidated at the molecular level and on a genome scale. The interplay between transcription factors activated by differentiation-promoting signals and master regulators likely exerts a crucial role in controlling stage-specific progression of the OL lineage. In this review, we describe the current state of knowledge regarding the transcription factors and the epigenetic programs including histone methylation, acetylation, chromatin remodeling, micro-RNAs, and noncoding RNAs that regulate development of OLs and myelination.
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Affiliation(s)
- Ben Emery
- Department of Anatomy and Neurobiology, University of Melbourne, Victoria 3010, Australia Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria 3010, Australia
| | - Q Richard Lu
- Department of Pediatrics, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
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91
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Bose R, Spulber S, Kilian P, Heldring N, Lönnerberg P, Johnsson A, Conti M, Hermanson O, Ceccatelli S. Tet3 mediates stable glucocorticoid-induced alterations in DNA methylation and Dnmt3a/Dkk1 expression in neural progenitors. Cell Death Dis 2015; 6:e1793. [PMID: 26086966 PMCID: PMC4669838 DOI: 10.1038/cddis.2015.159] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/28/2015] [Accepted: 05/13/2015] [Indexed: 12/15/2022]
Abstract
Developmental exposure to excess glucocorticoids (GCs) has harmful neurodevelopmental effects, which include persistent alterations in the differentiation potential of embryonic neural stem cells (NSCs). The mechanisms, however, are largely unknown. Here, we investigated the effects of dexamethasone (Dex, a synthetic GC analog) by MeDIP-like genome-wide analysis of differentially methylated DNA regions (DMRs) in NSCs isolated from embryonic rat cortices. We found that Dex-induced genome-wide DNA hypomethylation in the NSCs in vitro. Similarly, in utero exposure to Dex resulted in global DNA hypomethylation in the cerebral cortex of 3-day-old mouse pups. Dex-exposed NSCs displayed stable changes in the expression of the DNA methyltransferase Dnmt3a, and Dkk1, an essential factor for neuronal differentiation. These alterations were dependent on Tet3 upregulation. In conclusion, we propose that GCs elicit strong and persistent effects on DNA methylation in NSCs with Tet3 playing an essential role in the regulation of Dnmt3a and Dkk1. Noteworthy is the occurrence of similar changes in Dnmt3a and Dkk1 gene expression after exposure to excess GC in vivo.
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Affiliation(s)
- R Bose
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - S Spulber
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - P Kilian
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - N Heldring
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - P Lönnerberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - A Johnsson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - M Conti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - O Hermanson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - S Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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92
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Abstract
DNA methylation is a chemical modification that occurs predominantly on CG dinucleotides in mammalian genomes. However, recent studies have revealed that non-CG methylation (mCH) is abundant and nonrandomly distributed in the genomes of pluripotent cells and brain cells, and is present at lower levels in many other human cells and tissues. Surprisingly, mCH in pluripotent cells is distinct from that in brain cells in terms of sequence specificity and association with transcription, indicating the existence of different mCH pathways. In addition, several recent studies have begun to reveal the biological significance of mCH in diverse cellular processes. In reprogrammed somatic cells, mCH marks megabase-scale regions that have failed to revert to the pluripotent epigenetic state. In myocytes, promoter mCH accumulation is associated with the transcriptional response to environmental factors. In brain cells, mCH accumulates during the establishment of neural circuits and is associated with Rett syndrome. In this review, we summarize the current understanding of mCH and its possible functional consequences in different biological contexts.
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Affiliation(s)
- Yupeng He
- Bioinformatics Program, University of California, San Diego, La Jolla, California 92093
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93
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Sellars M, Huh JR, Day K, Issuree PD, Galan C, Gobeil S, Absher D, Green MR, Littman DR. Regulation of DNA methylation dictates Cd4 expression during the development of helper and cytotoxic T cell lineages. Nat Immunol 2015; 16:746-54. [PMID: 26030024 PMCID: PMC4474743 DOI: 10.1038/ni.3198] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 05/06/2015] [Indexed: 12/14/2022]
Abstract
During development, progenitor cells with binary potential give rise to daughter cells that have distinct functions. Heritable epigenetic mechanisms then lock in gene expression programs that define lineage identity. Cd4 regulation in helper and cytotoxic T cells exemplifies this process, with enhancer- and silencer-regulated establishment of epigenetic memories for stable gene expression and repression, respectively. Using a genetic screen, we identified the DNA methylation machinery as essential for maintaining Cd4 silencing in the cytotoxic lineage. Further, we found a requirement for the proximal enhancer in mediating removal of Cd4 DNA methylation marks, allowing for stable expression in T helper cells. These findings suggest that stage-specific methylation and demethylation events in Cd4 regulate its heritable expression in response to the distinct signals that dictate lineage choice during T cell development.
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Affiliation(s)
- MacLean Sellars
- 1] The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York, USA. [2] Howard Hughes Medical Institute, New York University School of Medicine, New York, New York, USA
| | - Jun R Huh
- 1] The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York, USA. [2] Howard Hughes Medical Institute, New York University School of Medicine, New York, New York, USA. [3] Division of Infectious Disease and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Kenneth Day
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Priya D Issuree
- 1] The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York, USA. [2] Howard Hughes Medical Institute, New York University School of Medicine, New York, New York, USA
| | - Carolina Galan
- 1] The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York, USA. [2] Howard Hughes Medical Institute, New York University School of Medicine, New York, New York, USA
| | - Stephane Gobeil
- 1] Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA. [2] Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Devin Absher
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Michael R Green
- 1] Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA. [2] Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Dan R Littman
- 1] The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York, USA. [2] Howard Hughes Medical Institute, New York University School of Medicine, New York, New York, USA
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94
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Shukla A, Sehgal M, Singh TR. Hydroxymethylation and its potential implication in DNA repair system: A review and future perspectives. Gene 2015; 564:109-18. [DOI: 10.1016/j.gene.2015.03.075] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/21/2015] [Accepted: 03/05/2015] [Indexed: 12/22/2022]
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95
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Shin J, Ming GL, Song H. DNA modifications in the mammalian brain. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0512. [PMID: 25135973 DOI: 10.1098/rstb.2013.0512] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
DNA methylation is a crucial epigenetic mark in mammalian development, genomic imprinting, X-inactivation, chromosomal stability and suppressing parasitic DNA elements. DNA methylation in neurons has also been suggested to play important roles for mammalian neuronal functions, and learning and memory. In this review, we first summarize recent discoveries and fundamental principles of DNA modifications in the general epigenetics field. We then describe the profiles of different DNA modifications in the mammalian brain genome. Finally, we discuss roles of DNA modifications in mammalian brain development and function.
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Affiliation(s)
- Jaehoon Shin
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guo-Li Ming
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hongjun Song
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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96
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MeCP2 binds to non-CG methylated DNA as neurons mature, influencing transcription and the timing of onset for Rett syndrome. Proc Natl Acad Sci U S A 2015; 112:5509-14. [PMID: 25870282 DOI: 10.1073/pnas.1505909112] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Epigenetic mechanisms, such as DNA methylation, regulate transcriptional programs to afford the genome flexibility in responding to developmental and environmental cues in health and disease. A prime example involving epigenetic dysfunction is the postnatal neurodevelopmental disorder Rett syndrome (RTT), which is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MeCP2). Despite decades of research, it remains unclear how MeCP2 regulates transcription or why RTT features appear 6-18 months after birth. Here we report integrated analyses of genomic binding of MeCP2, gene-expression data, and patterns of DNA methylation. In addition to the expected high-affinity binding to methylated cytosine in the CG context (mCG), we find a distinct epigenetic pattern of substantial MeCP2 binding to methylated cytosine in the non-CG context (mCH, where H = A, C, or T) in the adult brain. Unexpectedly, we discovered that genes that acquire elevated mCH after birth become preferentially misregulated in mouse models of MeCP2 disorders, suggesting that MeCP2 binding at mCH loci is key for regulating neuronal gene expression in vivo. This pattern is unique to the maturing and adult nervous system, as it requires the increase in mCH after birth to guide differential MeCP2 binding among mCG, mCH, and nonmethylated DNA elements. Notably, MeCP2 binds mCH with higher affinity than nonmethylated identical DNA sequences to influence the level of Bdnf, a gene implicated in the pathophysiology of RTT. This study thus provides insight into the molecular mechanism governing MeCP2 targeting and sheds light on the delayed onset of RTT symptoms.
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97
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Loss of Dnmt3a and endogenous Kras(G12D/+) cooperate to regulate hematopoietic stem and progenitor cell functions in leukemogenesis. Leukemia 2015; 29:1847-56. [PMID: 25801914 DOI: 10.1038/leu.2015.85] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/18/2015] [Accepted: 03/03/2015] [Indexed: 01/04/2023]
Abstract
Oncogenic NRAS and KRAS mutations are prevalent in human juvenile and chronic myelomonocytic leukemia (JMML/CMML). However, additional genetic mutations cooperating with oncogenic RAS in JMML/ CMML progression and/or their transformation to acute myeloid leukemia (AML) remain largely unknown. Here we tested the potential genetic interaction of DNMT3A mutations and oncogenic RAS mutations in leukemogenesis. We found that Dnmt3a(-/-) induces multiple hematopoietic phenotypes after a prolonged latency, including T-cell expansion in the peripheral blood, stress erythropoiesis in the spleen and myeloid malignancies in the liver. Dnmt3a(-/-) significantly promoted JMML/CMML progression and shortened the survival of Kras(G12D/+) mice in a cell-autonomous manner. Similarly, downregulating Dnmt3a also promoted myeloid malignancies in Nras(G12D/+) mice. Further studies show that Dnmt3a deficiency rescues Kras(G12D/+)-mediated depletion of hematopoietic stem cells and increases self-renewal of Kras(G12D/+) myeloid progenitors (MPs). Moreover, ~33% of animals developed an AML-like disease, which is driven by Kras(G12D/+); Dnmt3a(-/-) MPs. Consistent with our result, COSMIC database mining demonstrates that the combination of oncogenic RAS and DNMT3A mutations exclusively occurred in patients with JMML, CMML or AML. Our results suggest that DNMT3A mutations and oncogenic RAS cooperate to regulate hematopoietic stem and progenitor cells and promote myeloid malignancies.
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98
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Cheng Y, Xie N, Jin P, Wang T. DNA methylation and hydroxymethylation in stem cells. Cell Biochem Funct 2015; 33:161-73. [PMID: 25776144 DOI: 10.1002/cbf.3101] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 02/17/2015] [Accepted: 02/24/2015] [Indexed: 12/18/2022]
Abstract
In mammals, DNA methylation and hydroxymethylation are specific epigenetic mechanisms that can contribute to the regulation of gene expression and cellular functions. DNA methylation is important for the function of embryonic stem cells and adult stem cells (such as haematopoietic stem cells, neural stem cells and germline stem cells), and changes in DNA methylation patterns are essential for successful nuclear reprogramming. In the past several years, the rediscovery of hydroxymethylation and the TET enzymes expanded our insights tremendously and uncovered more dynamic aspects of cytosine methylation regulation. Here, we review the current knowledge and highlight the most recent advances in DNA methylation and hydroxymethylation in embryonic stem cells, induced pluripotent stem cells and several well-studied adult stems cells. Our current understanding of stem cell epigenetics and new advances in the field will undoubtedly stimulate further clinical applications of regenerative medicine in the future.
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Affiliation(s)
- Ying Cheng
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Nina Xie
- Department of Human Genetics, Emory University, Atlanta, GA, USA.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Peng Jin
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Tao Wang
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, CA, USA
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99
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Reading the unique DNA methylation landscape of the brain: Non-CpG methylation, hydroxymethylation, and MeCP2. Proc Natl Acad Sci U S A 2015; 112:6800-6. [PMID: 25739960 DOI: 10.1073/pnas.1411269112] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
DNA methylation at CpG dinucleotides is an important epigenetic regulator common to virtually all mammalian cell types, but recent evidence indicates that during early postnatal development neuronal genomes also accumulate uniquely high levels of two alternative forms of methylation, non-CpG methylation and hydroxymethylation. Here we discuss the distinct landscape of DNA methylation in neurons, how it is established, and how it might affect the binding and function of protein readers of DNA methylation. We review studies of one critical reader of DNA methylation in the brain, the Rett syndrome protein methyl CpG-binding protein 2 (MeCP2), and discuss how differential binding affinity of MeCP2 for non-CpG and hydroxymethylation may affect the function of this methyl-binding protein in the nervous system.
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100
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Nishikawa K, Iwamoto Y, Kobayashi Y, Katsuoka F, Kawaguchi SI, Tsujita T, Nakamura T, Kato S, Yamamoto M, Takayanagi H, Ishii M. DNA methyltransferase 3a regulates osteoclast differentiation by coupling to an S-adenosylmethionine-producing metabolic pathway. Nat Med 2015; 21:281-7. [PMID: 25706873 DOI: 10.1038/nm.3774] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Accepted: 11/20/2014] [Indexed: 12/13/2022]
Abstract
Metabolic reprogramming occurs in response to the cellular environment to mediate differentiation, but the fundamental mechanisms linking metabolic processes to differentiation programs remain to be elucidated. During osteoclast differentiation, a shift toward more oxidative metabolic processes occurs. In this study we identified the de novo DNA methyltransferase 3a (Dnmt3a) as a transcription factor that couples these metabolic changes to osteoclast differentiation. We also found that receptor activator of nuclear factor-κB ligand (RANKL), an essential cytokine for osteoclastogenesis, induces this metabolic shift towards oxidative metabolism, which is accompanied by an increase in S-adenosylmethionine (SAM) production. We found that SAM-mediated DNA methylation by Dnmt3a regulates osteoclastogenesis via epigenetic repression of anti-osteoclastogenic genes. The importance of Dnmt3a in bone homeostasis was underscored by the observations that Dnmt3a-deficient osteoclast precursor cells do not differentiate efficiently into osteoclasts and that mice with an osteoclast-specific deficiency in Dnmt3a have elevated bone mass due to a smaller number of osteoclasts. Furthermore, inhibition of DNA methylation by theaflavin-3,3'-digallate abrogated bone loss in models of osteoporosis. Thus, this study reveals the role of epigenetic processes in the regulation of cellular metabolism and differentiation, which may provide the molecular basis for a new therapeutic strategy for a variety of bone disorders.
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Affiliation(s)
- Keizo Nishikawa
- 1] Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Osaka, Japan. [2] WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan. [3] Japan Science and Technology Agency, CREST, Tokyo, Japan
| | - Yoriko Iwamoto
- 1] Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Osaka, Japan. [2] WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan. [3] Japan Science and Technology Agency, CREST, Tokyo, Japan. [4] Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | | | - Fumiki Katsuoka
- 1] Department of Integrative Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan. [2] Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shin-ichi Kawaguchi
- Department of Molecular Medicine and Therapy, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Tadayuki Tsujita
- Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Takashi Nakamura
- Department of Biochemistry, School of Medicine, Keio University, Tokyo, Japan
| | | | - Masayuki Yamamoto
- 1] Department of Integrative Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan. [2] Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroshi Takayanagi
- 1] Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Tokyo, Japan. [2] Japan Science and Technology Agency, ERATO, Takayanagi Osteonetwork Project, Tokyo, Japan
| | - Masaru Ishii
- 1] Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Osaka, Japan. [2] WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan. [3] Japan Science and Technology Agency, CREST, Tokyo, Japan
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