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Liao J, Karnik R, Gu H, Ziller MJ, Clement K, Tsankov AM, Akopian V, Gifford CA, Donaghey J, Galonska C, Pop R, Reyon D, Tsai SQ, Mallard W, Joung JK, Rinn JL, Gnirke A, Meissner A. Targeted disruption of DNMT1, DNMT3A and DNMT3B in human embryonic stem cells. Nat Genet 2015; 47:469-78. [PMID: 25822089 PMCID: PMC4414868 DOI: 10.1038/ng.3258] [Citation(s) in RCA: 346] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 03/06/2015] [Indexed: 12/14/2022]
Abstract
DNA methylation is a key epigenetic modification involved in regulating gene expression and maintaining genomic integrity. Here we inactivated all three catalytically active DNA methyltransferases (DNMTs) in human embryonic stem cells (ESCs) using CRISPR/Cas9 genome editing to further investigate the roles and genomic targets of these enzymes. Disruption of DNMT3A or DNMT3B individually as well as of both enzymes in tandem results in viable, pluripotent cell lines with distinct effects on the DNA methylation landscape, as assessed by whole-genome bisulfite sequencing. Surprisingly, in contrast to findings in mouse, deletion of DNMT1 resulted in rapid cell death in human ESCs. To overcome this immediate lethality, we generated a doxycycline-responsive tTA-DNMT1* rescue line and readily obtained homozygous DNMT1-mutant lines. However, doxycycline-mediated repression of exogenous DNMT1* initiates rapid, global loss of DNA methylation, followed by extensive cell death. Our data provide a comprehensive characterization of DNMT-mutant ESCs, including single-base genome-wide maps of the targets of these enzymes.
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Affiliation(s)
- Jing Liao
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Rahul Karnik
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Hongcang Gu
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Michael J. Ziller
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Kendell Clement
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Alexander M. Tsankov
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Veronika Akopian
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Casey A. Gifford
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Julie Donaghey
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Christina Galonska
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Ramona Pop
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Deepak Reyon
- Department of Pathology, Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Shengdar Q. Tsai
- Department of Pathology, Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - William Mallard
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - J. Keith Joung
- Department of Pathology, Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - John L. Rinn
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Andreas Gnirke
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Alexander Meissner
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
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Pollema-Mays SL, Centeno MV, Apkarian AV, Martina M. Expression of DNA methyltransferases in adult dorsal root ganglia is cell-type specific and up regulated in a rodent model of neuropathic pain. Front Cell Neurosci 2014; 8:217. [PMID: 25152711 PMCID: PMC4126486 DOI: 10.3389/fncel.2014.00217] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 07/17/2014] [Indexed: 11/13/2022] Open
Abstract
Neuropathic pain is associated with hyperexcitability and intrinsic firing of dorsal root ganglia (DRG) neurons. These phenotypical changes can be long lasting, potentially spanning the entire life of animal models, and depend on altered expression of numerous proteins, including many ion channels. Yet, how DRGs maintain long-term changes in protein expression in neuropathic conditions remains unclear. DNA methylation is a well-known mechanism of epigenetic control of gene expression and is achieved by the action of three enzymes: DNA methyltransferase (DNMT) 1, 3a, and 3b, which have been studied primarily during development. We first performed immunohistochemical analysis to assess whether these enzymes are expressed in adult rat DRGs (L4–5) and found that DNMT1 is expressed in both glia and neurons, DNMT3a is preferentially expressed in glia and DNMT3b is preferentially expressed in neurons. A rat model of neuropathic pain was then used to determine whether nerve injury may induce epigenetic changes in DRGs at multiple time points after pain onset. Real-time RT PCR analysis revealed robust and time-dependent changes in DNMT transcript expression in ipsilateral DRGs from spared nerve injury (SNI) but not sham rats. Interestingly, DNMT3b transcript showed a robust upregulation that appeared already 1 week after surgery and persisted at 4 weeks (our endpoint); in contrast, DNMT1 and DNMT3a transcripts showed only moderate upregulation that was transient and did not appear until the second week. We suggest that DNMT regulation in adult DRGs may be a contributor to the pain phenotype and merits further study.
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Affiliation(s)
- Sarah L Pollema-Mays
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | - Maria V Centeno
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | - A V Apkarian
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | - Marco Martina
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
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