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Wei X, Li J, Cheng Z, Wei S, Yu G, Olsen ML. Decoding the Epigenetic Landscape: Insights into 5mC and 5hmC Patterns in Mouse Cortical Cell Types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.06.602342. [PMID: 39026756 PMCID: PMC11257419 DOI: 10.1101/2024.07.06.602342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
The DNA modifications, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC), represent powerful epigenetic regulators of temporal and spatial gene expression. Yet, how the cooperation of these genome-wide, epigenetic marks determine unique transcriptional signatures across different brain cell populations is unclear. Here we applied Nanopore sequencing of native DNA to obtain a complete, genome-wide, single-base resolution atlas of 5mC and 5hmC modifications in neurons, astrocytes and microglia in the mouse cortex (99% genome coverage, 40 million CpG sites). In tandem with RNA sequencing, analysis of 5mC and 5hmC patterns across cell types reveals astrocytes drive uniquely high brain 5hmC levels and support two decades of research regarding methylation patterns, gene expression and alternative splicing, benchmarking this resource. As such, we provide the most comprehensive DNA methylation data in mouse brain as an interactive, online tool (NAM-Me, https://olsenlab.shinyapps.io/NAMME/) to serve as a resource dataset for those interested in the methylome landscape.
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Affiliation(s)
- Xiaoran Wei
- Biomedical and Veterinary Sciences Graduate Program, Virginia Tech, Blacksburg, VA, the United States
- School of Neuroscience, Virginia Tech, Blacksburg, VA, the United States
| | - Jiangtao Li
- School of Neuroscience, Virginia Tech, Blacksburg, VA, the United States
- Genetics, Bioinformatics and Computational Biology Graduate Program, Virginia Tech, Blacksburg, VA, the United States
| | - Zuolin Cheng
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Arlington, VA, the United States
| | - Songtao Wei
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Arlington, VA, the United States
| | - Guoqiang Yu
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Arlington, VA, the United States
| | - Michelle L Olsen
- School of Neuroscience, Virginia Tech, Blacksburg, VA, the United States
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2
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Liu L, Nguyen H, Das U, Ogunsola S, Yu J, Lei L, Kung M, Pejhan S, Rastegar M, Xie J. Epigenetic control of adaptive or homeostatic splicing during interval-training activities. Nucleic Acids Res 2024; 52:7211-7224. [PMID: 38661216 PMCID: PMC11229381 DOI: 10.1093/nar/gkae311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/03/2024] [Accepted: 04/14/2024] [Indexed: 04/26/2024] Open
Abstract
Interval-training activities induce adaptive cellular changes without altering their fundamental identity, but the precise underlying molecular mechanisms are not fully understood. In this study, we demonstrate that interval-training depolarization (ITD) of pituitary cells triggers distinct adaptive or homeostatic splicing responses of alternative exons. This occurs while preserving the steady-state expression of the Prolactin and other hormone genes. The nature of these splicing responses depends on the exon's DNA methylation status, the methyl-C-binding protein MeCP2 and its associated CA-rich motif-binding hnRNP L. Interestingly, the steady expression of the Prolactin gene is also reliant on MeCP2, whose disruption leads to exacerbated multi-exon aberrant splicing and overexpression of the hormone gene transcripts upon ITD, similar to the observed hyperprolactinemia or activity-dependent aberrant splicing in Rett Syndrome. Therefore, epigenetic control is crucial for both adaptive and homeostatic splicing and particularly the steady expression of the Prolactin hormone gene during ITD. Disruption in this regulation may have significant implications for the development of progressive diseases.
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Affiliation(s)
- Ling Liu
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Hai Nguyen
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Urmi Das
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Samuel Ogunsola
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Jiankun Yu
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Lei Lei
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Matthew Kung
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Shervin Pejhan
- Biochemistry & Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Mojgan Rastegar
- Biochemistry & Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Jiuyong Xie
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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Sonn JY, Kim W, Iwanaszko M, Aoi Y, Li Y, Parkitny L, Brissette JL, Weiner L, Al-Ramahi I, Botas J, Shilatifard A, Zoghbi HY. MeCP2 Interacts with the Super Elongation Complex to Regulate Transcription. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.30.601446. [PMID: 39005382 PMCID: PMC11244860 DOI: 10.1101/2024.06.30.601446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Loss-of-function mutations in methyl-CpG binding protein 2 ( MECP2 ) cause Rett syndrome, a postnatal neurodevelopmental disorder that occurs in ∼1/10,000 live female births. MeCP2 binds to methylated cytosines across genomic DNA and recruits various partners to regulate gene expression. MeCP2 has been shown to repress transcription in vitro and interacts with co-repressors such as the Sin3A and NCoR complexes. Based on these observations, MeCP2 has been largely considered as a repressor of transcription. However, a mouse model of RTT displays many down-regulated genes, and those same genes are up-regulated in a MECP2 duplication mouse model. Furthermore, TCF20, which has been associated with transcriptional activation, have recently been identified as a protein interactor of MeCP2. These data broaden the potential functions of MeCP2 as a regulator of gene expression. Yet, the molecular mechanisms underlying MeCP2-dependent gene regulation remain largely unknown. Here, using a human MECP2 gain-of-function Drosophila model, we screened for genetic modifiers of MECP2 -induced phenotypes. Our approach identified several subunits of the Drosophila super elongation complex, a P-TEFb containing RNA polymerase II (RNA pol II) elongation factor required for the release of promoter-proximally paused RNA pol II, as genetic interactors of MECP2 . We discovered that MeCP2 physically interacts with the SEC in human cells and in the mouse brain. Furthermore, we found that MeCP2 directly binds AFF4, the scaffold of the SEC, via the transcriptional repression domain. Finally, loss of MeCP2 in the mouse cortex caused reduced binding of AFF4 specifically on a subset of genes involved in the regulation of synaptic function, which also displayed the strongest decrease in RNA pol II binding in the genebody. Taken together, our study reveals a previously unrecognized mechanism through which MeCP2 regulates transcription, providing a new dimension to its regulatory role in gene expression.
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Liu Y, Flamier A, Bell GW, Diao AJ, Whitfield TW, Wang HC, Wu Y, Schulte F, Friesen M, Guo R, Mitalipova M, Liu XS, Vos SM, Young RA, Jaenisch R. MECP2 directly interacts with RNA polymerase II to modulate transcription in human neurons. Neuron 2024; 112:1943-1958.e10. [PMID: 38697112 DOI: 10.1016/j.neuron.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/08/2024] [Accepted: 04/05/2024] [Indexed: 05/04/2024]
Abstract
Mutations in the methyl-DNA-binding protein MECP2 cause the neurodevelopmental disorder Rett syndrome (RTT). How MECP2 contributes to transcriptional regulation in normal and disease states is unresolved; it has been reported to be an activator and a repressor. We describe here the first integrated CUT&Tag, transcriptome, and proteome analyses using human neurons with wild-type (WT) and mutant MECP2 molecules. MECP2 occupies CpG-rich promoter-proximal regions in over four thousand genes in human neurons, including a plethora of autism risk genes, together with RNA polymerase II (RNA Pol II). MECP2 directly interacts with RNA Pol II, and genes occupied by both proteins showed reduced expression in neurons with MECP2 patient mutations. We conclude that MECP2 acts as a positive cofactor for RNA Pol II gene expression at many neuronal genes that harbor CpG islands in promoter-proximal regions and that RTT is due, in part, to the loss of gene activity of these genes in neurons.
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Affiliation(s)
- Yi Liu
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Anthony Flamier
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - George W Bell
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Annette Jun Diao
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Troy W Whitfield
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Hao-Che Wang
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Yizhe Wu
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Fabian Schulte
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Max Friesen
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Ruisi Guo
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Maisam Mitalipova
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - X Shawn Liu
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Richard A Young
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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Pantier R, Brown M, Han S, Paton K, Meek S, Montavon T, Shukeir N, McHugh T, Kelly DA, Hochepied T, Libert C, Jenuwein T, Burdon T, Bird A. MeCP2 binds to methylated DNA independently of phase separation and heterochromatin organisation. Nat Commun 2024; 15:3880. [PMID: 38719804 PMCID: PMC11079052 DOI: 10.1038/s41467-024-47395-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 03/29/2024] [Indexed: 05/12/2024] Open
Abstract
Correlative evidence has suggested that the methyl-CpG-binding protein MeCP2 contributes to the formation of heterochromatin condensates via liquid-liquid phase separation. This interpretation has been reinforced by the observation that heterochromatin, DNA methylation and MeCP2 co-localise within prominent foci in mouse cells. The findings presented here revise this view. MeCP2 localisation is independent of heterochromatin as MeCP2 foci persist even when heterochromatin organisation is disrupted. Additionally, MeCP2 foci fail to show hallmarks of phase separation in live cells. Importantly, we find that mouse cellular models are highly atypical as MeCP2 distribution is diffuse in most mammalian species, including humans. Notably, MeCP2 foci are absent in Mus spretus which is a mouse subspecies lacking methylated satellite DNA repeats. We conclude that MeCP2 has no intrinsic tendency to form condensates and its localisation is independent of heterochromatin. Instead, the distribution of MeCP2 in the nucleus is primarily determined by global DNA methylation patterns.
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Affiliation(s)
- Raphaël Pantier
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Megan Brown
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Sicheng Han
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Katie Paton
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Stephen Meek
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Thomas Montavon
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Nicholas Shukeir
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Toni McHugh
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - David A Kelly
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Tino Hochepied
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Claude Libert
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Thomas Jenuwein
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Tom Burdon
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK.
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6
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Tooley KB, Chucair-Elliott AJ, Ocañas SR, Machalinski AH, Pham KD, Hoolehan W, Kulpa AM, Stanford DR, Freeman WM. Differential usage of DNA modifications in neurons, astrocytes, and microglia. Epigenetics Chromatin 2023; 16:45. [PMID: 37953264 PMCID: PMC10642035 DOI: 10.1186/s13072-023-00522-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 11/06/2023] [Indexed: 11/14/2023] Open
Abstract
BACKGROUND Cellular identity is determined partly by cell type-specific epigenomic profiles that regulate gene expression. In neuroscience, there is a pressing need to isolate and characterize the epigenomes of specific CNS cell types in health and disease. In this study, we developed an in vivo tagging mouse model (Camk2a-NuTRAP) for paired isolation of neuronal DNA and RNA without cell sorting and then used this model to assess epigenomic regulation, DNA modifications in particular, of gene expression between neurons and glia. RESULTS After validating the cell-specificity of the Camk2a-NuTRAP model, we performed TRAP-RNA-Seq and INTACT-whole genome oxidative bisulfite sequencing (WGoxBS) to assess the neuronal translatome and epigenome in the hippocampus of young mice (4 months old). WGoxBS findings were validated with enzymatic methyl-Seq (EM-Seq) and nanopore sequencing. Comparing neuronal data to microglial and astrocytic data from NuTRAP models, microglia had the highest global mCG levels followed by astrocytes and then neurons, with the opposite pattern observed for hmCG and mCH. Differentially modified regions between cell types were predominantly found within gene bodies and distal intergenic regions, rather than proximal promoters. Across cell types there was a negative correlation between DNA modifications (mCG, mCH, hmCG) and gene expression at proximal promoters. In contrast, a negative correlation of gene body mCG and a positive relationship between distal promoter and gene body hmCG with gene expression was observed. Furthermore, we identified a neuron-specific inverse relationship between mCH and gene expression across promoter and gene body regions. CONCLUSIONS Neurons, astrocytes, and microglia demonstrate different genome-wide levels of mCG, hmCG, and mCH that are reproducible across analytical methods. However, modification-gene expression relationships are conserved across cell types. Enrichment of differential modifications across cell types in gene bodies and distal regulatory elements, but not proximal promoters, highlights epigenomic patterning in these regions as potentially greater determinants of cell identity. These findings also demonstrate the importance of differentiating between mC and hmC in neuroepigenomic analyses, as up to 30% of what is conventionally interpreted as mCG can be hmCG, which often has a different relationship to gene expression than mCG.
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Affiliation(s)
- Kyla B Tooley
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Ana J Chucair-Elliott
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Sarah R Ocañas
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Adeline H Machalinski
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Kevin D Pham
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Walker Hoolehan
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Adam M Kulpa
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - David R Stanford
- Center for Biomedical Data Sciences, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Willard M Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK, USA.
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7
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Yang J, Horton JR, Liu B, Corces VG, Blumenthal RM, Zhang X, Cheng X. Structures of CTCF-DNA complexes including all 11 zinc fingers. Nucleic Acids Res 2023; 51:8447-8462. [PMID: 37439339 PMCID: PMC10484683 DOI: 10.1093/nar/gkad594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/14/2023] Open
Abstract
The CCCTC-binding factor (CTCF) binds tens of thousands of enhancers and promoters on mammalian chromosomes by means of its 11 tandem zinc finger (ZF) DNA-binding domain. In addition to the 12-15-bp CORE sequence, some of the CTCF binding sites contain 5' upstream and/or 3' downstream motifs. Here, we describe two structures for overlapping portions of human CTCF, respectively, including ZF1-ZF7 and ZF3-ZF11 in complex with DNA that incorporates the CORE sequence together with either 3' downstream or 5' upstream motifs. Like conventional tandem ZF array proteins, ZF1-ZF7 follow the right-handed twist of the DNA, with each finger occupying and recognizing one triplet of three base pairs in the DNA major groove. ZF8 plays a unique role, acting as a spacer across the DNA minor groove and positioning ZF9-ZF11 to make cross-strand contacts with DNA. We ascribe the difference between the two subgroups of ZF1-ZF7 and ZF8-ZF11 to residues at the two positions -6 and -5 within each finger, with small residues for ZF1-ZF7 and bulkier and polar/charged residues for ZF8-ZF11. ZF8 is also uniquely rich in basic amino acids, which allows salt bridges to DNA phosphates in the minor groove. Highly specific arginine-guanine and glutamine-adenine interactions, used to recognize G:C or A:T base pairs at conventional base-interacting positions of ZFs, also apply to the cross-strand interactions adopted by ZF9-ZF11. The differences between ZF1-ZF7 and ZF8-ZF11 can be rationalized structurally and may contribute to recognition of high-affinity CTCF binding sites.
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Affiliation(s)
- Jie Yang
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - John R Horton
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Bin Liu
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Victor G Corces
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Robert M Blumenthal
- Department of Medical Microbiology and Immunology, and Program in Bioinformatics, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Xing Zhang
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xiaodong Cheng
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Oluigbo DC. Rett Syndrome: A Tale of Altered Genetics, Synaptic Plasticity, and Neurodevelopmental Dynamics. Cureus 2023; 15:e41555. [PMID: 37554594 PMCID: PMC10405636 DOI: 10.7759/cureus.41555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2023] [Indexed: 08/10/2023] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder that is a leading cause of severe cognitive and physical impairment. RTT typically occurs in females, although rare cases of males with the disease exist. Its genetic cause, symptoms, and clinical progression timeline have also become well-documented since its initial discovery. However, a relatively late diagnosis and lack of an available cure signify that our understanding of the disease is incomplete. Innovative research methods and tools are thereby helping to fill gaps in our knowledge of RTT. Specifically, mouse models of RTT, video analysis, and retrospective parental analysis are well-established tools that provide valuable insights into RTT. Moreover, current and anticipated treatment options are improving the quality of life of the RTT patient population. Collectively, these developments are creating optimistic future perspectives for RTT.
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Affiliation(s)
- David C Oluigbo
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, USA
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9
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Tooley KB, Chucair-Elliott AJ, Ocañas SR, Machalinski AH, Pham KD, Stanford DR, Freeman WM. Differential usage of DNA modifications in neurons, astrocytes, and microglia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543497. [PMID: 37333391 PMCID: PMC10274634 DOI: 10.1101/2023.06.05.543497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Cellular identity is determined partly by cell type-specific epigenomic profiles that regulate gene expression. In neuroscience, there is a pressing need to isolate and characterize the epigenomes of specific CNS cell types in health and disease. This is especially true as for DNA modifications where most data are derived from bisulfite sequencing that cannot differentiate between DNA methylation and hydroxymethylation. In this study, we developed an in vivo tagging mouse model (Camk2a-NuTRAP) for paired isolation of neuronal DNA and RNA without cell sorting and then used this model to assess epigenomic regulation of gene expression between neurons and glia. Results After validating the cell-specificity of the Camk2a-NuTRAP model, we performed TRAP-RNA-Seq and INTACT whole genome oxidative bisulfite sequencing to assess the neuronal translatome and epigenome in the hippocampus of young mice (3 months old). These data were then compared to microglial and astrocytic data from NuTRAP models. When comparing the different cell types, microglia had the highest global mCG levels followed by astrocytes and then neurons, with the opposite pattern observed for hmCG and mCH. Differentially modified regions between cell types were predominantly found within gene bodies and distal intergenic regions, with limited differences occurring within proximal promoters. Across cell types there was a negative correlation between DNA modifications (mCG, mCH, hmCG) and gene expression at proximal promoters. In contrast, a negative correlation of mCG with gene expression within the gene body while a positive relationship between distal promoter and gene body hmCG and gene expression was observed. Furthermore, we identified a neuron-specific inverse relationship between mCH and gene expression across promoter and gene body regions. Conclusions In this study, we identified differential usage of DNA modifications across CNS cell types, and assessed the relationship between DNA modifications and gene expression in neurons and glia. Despite having different global levels, the general modification-gene expression relationship was conserved across cell types. The enrichment of differential modifications in gene bodies and distal regulatory elements, but not proximal promoters, across cell types highlights epigenomic patterning in these regions as potentially greater determinants of cell identity.
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Affiliation(s)
- Kyla B. Tooley
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Ana J. Chucair-Elliott
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Sarah R. Ocañas
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Adeline H. Machalinski
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Kevin D. Pham
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - David R. Stanford
- Center for Biomedical Data Sciences, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Willard M. Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK USA
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10
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Lee S, Choi J, Park J, Hong CP, Choi D, Han S, Choi K, Roh TY, Hwang D, Hwang I. DDM1-mediated gene body DNA methylation is associated with inducible activation of defense-related genes in Arabidopsis. Genome Biol 2023; 24:106. [PMID: 37147734 PMCID: PMC10161647 DOI: 10.1186/s13059-023-02952-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 04/24/2023] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND Plants memorize previous pathogen attacks and are "primed" to produce a faster and stronger defense response, which is critical for defense against pathogens. In plants, cytosines in transposons and gene bodies are reported to be frequently methylated. Demethylation of transposons can affect disease resistance by regulating the transcription of nearby genes during defense response, but the role of gene body methylation (GBM) in defense responses remains unclear. RESULTS Here, we find that loss of the chromatin remodeler decrease in DNA methylation 1 (ddm1) synergistically enhances resistance to a biotrophic pathogen under mild chemical priming. DDM1 mediates gene body methylation at a subset of stress-responsive genes with distinct chromatin properties from conventional gene body methylated genes. Decreased gene body methylation in loss of ddm1 mutant is associated with hyperactivation of these gene body methylated genes. Knockout of glyoxysomal protein kinase 1 (gpk1), a hypomethylated gene in ddm1 loss-of-function mutant, impairs priming of defense response to pathogen infection in Arabidopsis. We also find that DDM1-mediated gene body methylation is prone to epigenetic variation among natural Arabidopsis populations, and GPK1 expression is hyperactivated in natural variants with demethylated GPK1. CONCLUSIONS Based on our collective results, we propose that DDM1-mediated GBM provides a possible regulatory axis for plants to modulate the inducibility of the immune response.
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Affiliation(s)
- Seungchul Lee
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea
| | - Jaemyung Choi
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea
- Department of Cell & Developmental Biology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Jihwan Park
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea
| | - Chang Pyo Hong
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea
| | - Daeseok Choi
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang, 37673, Korea
| | - Soeun Han
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea
| | - Kyuha Choi
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea
| | - Tae-Young Roh
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea.
| | - Daehee Hwang
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Korea.
| | - Ildoo Hwang
- Department of Life Sciences, POSTECH, Pohang, 37673, Korea.
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11
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Martin S, Poppe D, Olova N, O'Leary C, Ivanova E, Pflueger J, Dechka J, Simmons RK, Cooper HM, Reik W, Lister R, Wolvetang EJ. Embryonic Stem Cell-Derived Neurons as a Model System for Epigenome Maturation during Development. Genes (Basel) 2023; 14:genes14050957. [PMID: 37239317 DOI: 10.3390/genes14050957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/16/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
DNA methylation in neurons is directly linked to neuronal genome regulation and maturation. Unlike other tissues, vertebrate neurons accumulate high levels of atypical DNA methylation in the CH sequence context (mCH) during early postnatal brain development. Here, we investigate to what extent neurons derived in vitro from both mouse and human pluripotent stem cells recapitulate in vivo DNA methylation patterns. While human ESC-derived neurons did not accumulate mCH in either 2D culture or 3D organoid models even after prolonged culture, cortical neurons derived from mouse ESCs acquired in vivo levels of mCH over a similar time period in both primary neuron cultures and in vivo development. mESC-derived neuron mCH deposition was coincident with a transient increase in Dnmt3a, preceded by the postmitotic marker Rbfox3 (NeuN), was enriched at the nuclear lamina, and negatively correlated with gene expression. We further found that methylation patterning subtly differed between in vitro mES-derived and in vivo neurons, suggesting the involvement of additional noncell autonomous processes. Our findings show that mouse ESC-derived neurons, in contrast to those of humans, can recapitulate the unique DNA methylation landscape of adult neurons in vitro over experimentally tractable timeframes, which allows their use as a model system to study epigenome maturation over development.
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Affiliation(s)
- Sally Martin
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel Poppe
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Nelly Olova
- Epigenetics ISP, The Babraham Institute, Cambridge CB22 3AT, UK
| | - Conor O'Leary
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Elena Ivanova
- Epigenetics ISP, The Babraham Institute, Cambridge CB22 3AT, UK
| | - Jahnvi Pflueger
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Jennifer Dechka
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rebecca K Simmons
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Helen M Cooper
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Wolf Reik
- Epigenetics ISP, The Babraham Institute, Cambridge CB22 3AT, UK
- The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK
| | - Ryan Lister
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Ernst J Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
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12
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Rodrigues DC, Mufteev M, Yuki KE, Narula A, Wei W, Piekna A, Liu J, Pasceri P, Rissland OS, Wilson MD, Ellis J. Buffering of transcription rate by mRNA half-life is a conserved feature of Rett syndrome models. Nat Commun 2023; 14:1896. [PMID: 37019888 PMCID: PMC10076348 DOI: 10.1038/s41467-023-37339-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/13/2023] [Indexed: 04/07/2023] Open
Abstract
Transcriptional changes in Rett syndrome (RTT) are assumed to directly correlate with steady-state mRNA levels, but limited evidence in mice suggests that changes in transcription can be compensated by post-transcriptional regulation. We measure transcription rate and mRNA half-life changes in RTT patient neurons using RATEseq, and re-interpret nuclear and whole-cell RNAseq from Mecp2 mice. Genes are dysregulated by changing transcription rate or half-life and are buffered when both change. We utilized classifier models to predict the direction of transcription rate changes and find that combined frequencies of three dinucleotides are better predictors than CA and CG. MicroRNA and RNA-binding Protein (RBP) motifs are enriched in 3'UTRs of genes with half-life changes. Nuclear RBP motifs are enriched on buffered genes with increased transcription rate. We identify post-transcriptional mechanisms in humans and mice that alter half-life or buffer transcription rate changes when a transcriptional modulator gene is mutated in a neurodevelopmental disorder.
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Affiliation(s)
- Deivid C Rodrigues
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Marat Mufteev
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Kyoko E Yuki
- Genetics & Genome Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Ashrut Narula
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Molecular Medicine, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Wei Wei
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Alina Piekna
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Jiajie Liu
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Peter Pasceri
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Olivia S Rissland
- Molecular Medicine, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- RNA Bioscience Initiative and Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Michael D Wilson
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Genetics & Genome Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - James Ellis
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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13
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PerezGrovas-Saltijeral A, Rajkumar AP, Knight HM. Differential expression of m 5C RNA methyltransferase genes NSUN6 and NSUN7 in Alzheimer's disease and traumatic brain injury. Mol Neurobiol 2023; 60:2223-2235. [PMID: 36646969 PMCID: PMC9984329 DOI: 10.1007/s12035-022-03195-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 12/23/2022] [Indexed: 01/18/2023]
Abstract
Epigenetic processes have become increasingly relevant in understanding disease-modifying mechanisms. 5-Methylcytosine methylations of DNA (5mC) and RNA (m5C) have functional transcriptional and RNA translational consequences and are tightly regulated by writer, reader and eraser effector proteins. To investigate the involvement of 5mC/5hmC and m5C effector proteins contributing to the development of dementia neuropathology, RNA sequencing data of 31 effector proteins across four brain regions was examined in 56 aged non-affected and 51 Alzheimer's disease (AD) individuals obtained from the Aging, Dementia and Traumatic Brain Injury Study. Gene expression profiles were compared between AD and controls, between neuropathological Braak and CERAD scores and in individuals with a history of traumatic brain injury (TBI). We found an increase in the DNA methylation writers DNMT1, DNMT3A and DNMT3B messenger RNA (mRNA) and a decrease in the reader UHRF1 mRNA in AD samples across three brain regions whilst the DNA erasers GADD45B and AICDA showed changes in mRNA abundance within neuropathological load groupings. RNA methylation writers NSUN6 and NSUN7 showed significant expression differences with AD and, along with the reader ALYREF, differences in expression for neuropathologic ranking. A history of TBI was associated with a significant increase in the DNA readers ZBTB4 and MeCP2 (p < 0.05) and a decrease in NSUN6 (p < 0.001) mRNA. These findings implicate regulation of protein pathways disrupted in AD and TBI via multiple pre- and post-transcriptional mechanisms including potentially acting upon transfer RNAs, enhancer RNAs as well as nuclear-cytoplasmic shuttling and cytoplasmic translational control. The targeting of such processes provides new therapeutic avenues for neurodegenerative brain conditions.
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Affiliation(s)
| | - Anto P Rajkumar
- Institute of Mental Health, Mental Health and Clinical Neurosciences Academic Unit, School of Medicine, University of Nottingham, Nottingham, UK.,Mental Health Services for Older People, Nottinghamshire Healthcare NHS Foundation Trust, Nottingham, UK
| | - Helen Miranda Knight
- Division of Cells, Organisms and Molecular Genetics, School of Life Sciences, University of Nottingham, Nottingham, UK.
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14
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Bazi Bushen mitigates epigenetic aging and extends healthspan in naturally aging mice. Biomed Pharmacother 2023; 160:114384. [PMID: 36764132 DOI: 10.1016/j.biopha.2023.114384] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/18/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Bazi Bushen (BZBS), a traditional Chinese medicine, has been proven effective in the treatment of age-related disease in mouse models. However, whether its therapeutic effects are due to antiaging mechanism has not yet been explored. In the present study, we investigated the antiaging effects of BZBS in naturally aging mice by using behavioral tests, liver DNA methylome sequencing, methylation age estimation, and frailty index assessment. The methylome analysis revealed a decrease of mCpG levels in the aged mouse liver. BZBS treatment tended to restore age-associated methylation decline and prune the methylation pattern toward that of young mice. More importantly, BZBS significantly rejuvenated methylation age of the aged mice, which was computed by an upgraded DNA methylation clock. These results were consistent with enhanced memory and muscular endurance, as well as decreased frailty score and liver pathological changes. KEGG analysis together with aging-related database screening identified methylation-targeted pathways upon BZBS treatment, including oxidative stress, DNA repair, MAPK signaling, and inflammation. Upregulation of key effectors and their downstream effects on elevating Sod2 expression and diminishing DNA damage were further investigated. Finally, in vitro experiments with senescent HUVECs proved a direct effect of BZBS extracts on the regulation of methylation enzymes during cellular aging. In summary, our work has revealed for the first time the antiaging effects of BZBS by slowing the methylation aging. These results suggest that BZBS might have great potential to extend healthspan and also explored the mechanism of BZBS action in the treatment of age-related diseases.
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15
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Stoeger T. The Road Less Traveled: Uncovering the Convergence Toward Specific Pleiotropic Phenotypes in Aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534472. [PMID: 37034589 PMCID: PMC10081180 DOI: 10.1101/2023.03.28.534472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Aging is a complex process influenced by a wide range of environmental and molecular factors. Despite this complexity, individuals tend to age in highly similar ways, leading to the question of what drives this convergence. Recent research, including my own discoveries, suggests that the length of transcript molecules plays a crucial role in age-dependent changes to the transcriptome. Drawing inspiration from the road trip analogy of cellular transcription, I propose that a non-linear scaling law drives convergence towards specific pleiotropic phenotypes in biological aging. This scaling law is based on the notion that molecular changes observed during aging may reflect unspecific damage to cellular physiology. By validating this hypothesis, I can improve our understanding of biological aging and identify new candidate compounds for anti-aging interventions, as well as re-identify one known intervention. This work has actionable implications for improving human health and extending lifespans.
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Affiliation(s)
- Thomas Stoeger
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
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16
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Alexander-Howden B, Zhang L, van der Sloot AM, Tollis S, St-Cyr DJ, Sicheri F, Bird AP, Tyers M, Lyst MJ. A screen for MeCP2-TBL1 interaction inhibitors using a luminescence-based assay. Sci Rep 2023; 13:3868. [PMID: 36890145 PMCID: PMC9995496 DOI: 10.1038/s41598-023-29915-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/13/2023] [Indexed: 03/10/2023] Open
Abstract
Understanding the molecular pathology of neurodevelopmental disorders should aid the development of therapies for these conditions. In MeCP2 duplication syndrome (MDS)-a severe autism spectrum disorder-neuronal dysfunction is caused by increased levels of MeCP2. MeCP2 is a nuclear protein that binds to methylated DNA and recruits the nuclear co-repressor (NCoR) complex to chromatin via an interaction with the WD repeat-containing proteins TBL1 and TBLR1. The peptide motif in MeCP2 that binds to TBL1/TBLR1 is essential for the toxicity of excess MeCP2 in animal models of MDS, suggesting that small molecules capable of disrupting this interaction might be useful therapeutically. To facilitate the search for such compounds, we devised a simple and scalable NanoLuc luciferase complementation assay for measuring the interaction of MeCP2 with TBL1/TBLR1. The assay allowed excellent separation between positive and negative controls, and had low signal variance (Z-factor = 0.85). We interrogated compound libraries using this assay in combination with a counter-screen based on luciferase complementation by the two subunits of protein kinase A (PKA). Using this dual screening approach, we identified candidate inhibitors of the interaction between MeCP2 and TBL1/TBLR1. This work demonstrates the feasibility of future screens of large compound collections, which we anticipate will enable the development of small molecule therapeutics to ameliorate MDS.
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Affiliation(s)
- Beatrice Alexander-Howden
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Li Zhang
- Institute for Research in Immunology and Cancer (IRIC), Department of Medicine, Université de Montréal, Montréal, Québec, H3T 1J4, Canada
| | - Almer M van der Sloot
- Institute for Research in Immunology and Cancer (IRIC), Department of Medicine, Université de Montréal, Montréal, Québec, H3T 1J4, Canada
- Mila - Quebec Artificial Intelligence Institute, 6666 Rue Saint-Urbain, Montréal, QC, H2S 3H1, Canada
| | - Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, 70210, Kuopio, Finland
| | - Daniel J St-Cyr
- Institute for Research in Immunology and Cancer (IRIC), Department of Medicine, Université de Montréal, Montréal, Québec, H3T 1J4, Canada
- X-Chem Inc, 7171 Frederick-Banting, Montréal, QC, H4S 1Z9, Canada
| | - Frank Sicheri
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, M5G 1X5, Canada
| | - Adrian P Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK.
| | - Mike Tyers
- Institute for Research in Immunology and Cancer (IRIC), Department of Medicine, Université de Montréal, Montréal, Québec, H3T 1J4, Canada.
- The Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
| | - Matthew J Lyst
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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17
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Jin Y, Su K, Kong HE, Ma W, Wang Z, Li Y, Li R, Allen EG, Wu H, Jin P. Cell type-specific DNA methylome signatures reveal epigenetic mechanisms for neuronal diversity and neurodevelopmental disorder. Hum Mol Genet 2023; 32:218-230. [PMID: 35947991 PMCID: PMC9840206 DOI: 10.1093/hmg/ddac189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 01/19/2023] Open
Abstract
DNA methylation plays a critical function in establishing and maintaining cell identity in brain. Disruption of DNA methylation-related processes leads to diverse neurological disorders. However, the role of DNA methylation characteristics in neuronal diversity remains underexplored. Here, we report detailed context-specific DNA methylation maps for GABAergic, glutamatergic (Glu) and Purkinje neurons, together with matched transcriptome profiles. Genome-wide mCH levels are distinguishable, while the mCG levels are similar among the three cell types. Substantial CG-differentially methylated regions (DMRs) are also seen, with Glu neurons experiencing substantial hypomethylation events. The relationship between mCG levels and gene expression displays cell type-specific patterns, while genic CH methylation exhibits a negative effect on transcriptional abundance. We found that cell type-specific CG-DMRs are informative in terms of represented neuronal function. Furthermore, we observed that the identified Glu-specific hypo-DMRs have a high level of consistency with the chromatin accessibility of excitatory neurons and the regions enriched for histone modifications (H3K27ac and H3K4me1) of active enhancers, suggesting their regulatory potential. Hypomethylation regions specific to each cell type are predicted to bind neuron type-specific transcription factors. Finally, we show that the DNA methylation changes in a mouse model of Rett syndrome, a neurodevelopmental disorder caused by the de novo mutations in MECP2, are cell type- and brain region-specific. Our results suggest that cell type-specific DNA methylation signatures are associated with the functional characteristics of the neuronal subtypes. The presented results emphasize the importance of DNA methylation-mediated epigenetic regulation in neuronal diversity and disease.
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Affiliation(s)
- Yulin Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kenong Su
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA 30322, USA
| | - Ha Eun Kong
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Wenjing Ma
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA 30322, USA
| | - Zhiqin Wang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yujing Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ronghua Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Emily G Allen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
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18
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Epstein RJ, Lin FPY, Brink RA, Blackburn J. Synonymous alterations of cancer-associated Trp53 CpG mutational hotspots cause fatal developmental jaw malocclusions but no tumors in knock-in mice. PLoS One 2023; 18:e0284327. [PMID: 37053216 PMCID: PMC10101519 DOI: 10.1371/journal.pone.0284327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
Intragenic CpG dinucleotides are tightly conserved in evolution yet are also vulnerable to methylation-dependent mutation, raising the question as to why these functionally critical sites have not been deselected by more stable coding sequences. We previously showed in cell lines that altered exonic CpG methylation can modify promoter start sites, and hence protein isoform expression, for the human TP53 tumor suppressor gene. Here we extend this work to the in vivo setting by testing whether synonymous germline modifications of exonic CpG sites affect murine development, fertility, longevity, or cancer incidence. We substituted the DNA-binding exons 5-8 of Trp53, the mouse ortholog of human TP53, with variant-CpG (either CpG-depleted or -enriched) sequences predicted to encode the normal p53 amino acid sequence; a control construct was also created in which all non-CpG sites were synonymously substituted. Homozygous Trp53-null mice were the only genotype to develop tumors. Mice with variant-CpG Trp53 sequences remained tumor-free, but were uniquely prone to dental anomalies causing jaw malocclusion (p < .0001). Since the latter phenotype also characterises murine Rett syndrome due to dysfunction of the trans-repressive MeCP2 methyl-CpG-binding protein, we hypothesise that CpG sites may exert non-coding phenotypic effects via pre-translational cis-interactions of 5-methylcytosine with methyl-binding proteins which regulate mRNA transcript initiation, expression or splicing, although direct effects on mRNA structure or translation are also possible.
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Affiliation(s)
- Richard J Epstein
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
| | - Frank P Y Lin
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Centre for Clinical Genomics, The Kinghorn Cancer Centre, Sydney, Australia
| | - Robert A Brink
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
| | - James Blackburn
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
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19
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Chhatbar K, Connelly J, Webb S, Kriaucionis S, Bird A. A critique of the hypothesis that CA repeats are primary targets of neuronal MeCP2. Life Sci Alliance 2022; 5:5/12/e202201522. [PMID: 36122935 PMCID: PMC9485053 DOI: 10.26508/lsa.202201522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 11/24/2022] Open
Abstract
The DNA-binding protein MeCP2 is reported to bind methylated cytosine in CG and CA motifs in genomic DNA, but it was recently proposed that arrays of tandemly repeated CA containing either methylated or hydroxymethylated cytosine are the primary targets for MeCP2 binding and function. Here we investigated the predictions of this hypothesis using a range of published datasets. We failed to detect enrichment of cytosine modification at genomic CA repeat arrays in mouse brain regions and found no evidence for preferential MeCP2 binding at CA repeats. Moreover, we did not observe a correlation between the CA repeat density near genes and their degree of transcriptional deregulation when MeCP2 was absent. Our results do not provide support for the hypothesis that CA repeats are key mediators of MeCP2 function. Instead, we found that CA repeats are subject to CAC methylation to a degree that is typical of the surrounding genome and contribute modestly to MeCP2-mediated modulation of gene expression in accordance with their content of this canonical target motif.
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Affiliation(s)
- Kashyap Chhatbar
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK.,Informatics Forum, School of Informatics, University of Edinburgh, Edinburgh, UK
| | - John Connelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK
| | | | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK
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20
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Sinnamon JR, Jacobson ME, Yung JF, Fisk JR, Jeng S, McWeeney SK, Parmelee LK, Chan CN, Yee SP, Mandel G. Targeted RNA editing in brainstem alleviates respiratory dysfunction in a mouse model of Rett syndrome. Proc Natl Acad Sci U S A 2022; 119:e2206053119. [PMID: 35939700 PMCID: PMC9388114 DOI: 10.1073/pnas.2206053119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/27/2022] [Indexed: 12/26/2022] Open
Abstract
Rett syndrome is a neurological disease due to loss-of-function mutations in the transcription factor, Methyl CpG binding protein 2 (MECP2). Because overexpression of endogenous MECP2 also causes disease, we have exploited a targeted RNA-editing approach to repair patient mutations where levels of MECP2 protein will never exceed endogenous levels. Here, we have constructed adeno-associated viruses coexpressing a bioengineered wild-type ADAR2 catalytic domain (Editasewt) and either Mecp2-targeting or nontargeting gfp RNA guides. The viruses are introduced systemically into male mice containing a guanosine to adenosine mutation that eliminates MeCP2 protein and causes classic Rett syndrome in humans. We find that in the mutant mice injected with the Mecp2-targeting virus, the brainstem exhibits the highest RNA-editing frequency compared to other brain regions. The efficiency is sufficient to rescue MeCP2 expression and function in the brainstem of mice expressing the Mecp2-targeting virus. Correspondingly, we find that abnormal Rett-like respiratory patterns are alleviated, and survival is prolonged, compared to mice injected with the control gfp guide virus. The levels of RNA editing among most brain regions corresponds to the distribution of guide RNA rather than Editasewt. Our results provide evidence that a targeted RNA-editing approach can alleviate a hallmark symptom in a mouse model of human disease.
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Affiliation(s)
- John R. Sinnamon
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | | | - John F. Yung
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | - Jenna R. Fisk
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | - Sophia Jeng
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239
| | - Shannon K. McWeeney
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239
- Division of Bioinformatics and Computational Biology, Oregon Health and Science University, Portland, OR 97239
- Department of Medical Informatics and Clinical Epidemiology, Oregon Health and Science University, Portland, OR 97239
- Oregon Clinical and Translational Research Institute, Oregon Health and Science University, Portland, OR 97239
| | - Lindsay K. Parmelee
- Integrated Pathology Core, Oregon National Primate Research Center, Beaverton, OR 97006
| | - Chi Ngai Chan
- Integrated Pathology Core, Oregon National Primate Research Center, Beaverton, OR 97006
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030
| | - Gail Mandel
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
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21
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Li J, Pinto-Duarte A, Zander M, Cuoco MS, Lai CY, Osteen J, Fang L, Luo C, Lucero JD, Gomez-Castanon R, Nery JR, Silva-Garcia I, Pang Y, Sejnowski TJ, Powell SB, Ecker JR, Mukamel EA, Behrens MM. Dnmt3a knockout in excitatory neurons impairs postnatal synapse maturation and increases the repressive histone modification H3K27me3. eLife 2022; 11:e66909. [PMID: 35604009 PMCID: PMC9170249 DOI: 10.7554/elife.66909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/22/2022] [Indexed: 11/13/2022] Open
Abstract
Two epigenetic pathways of transcriptional repression, DNA methylation and polycomb repressive complex 2 (PRC2), are known to regulate neuronal development and function. However, their respective contributions to brain maturation are unknown. We found that conditional loss of the de novo DNA methyltransferase Dnmt3a in mouse excitatory neurons altered expression of synapse-related genes, stunted synapse maturation, and impaired working memory and social interest. At the genomic level, loss of Dnmt3a abolished postnatal accumulation of CG and non-CG DNA methylation, leaving adult neurons with an unmethylated, fetal-like epigenomic pattern at ~222,000 genomic regions. The PRC2-associated histone modification, H3K27me3, increased at many of these sites. Our data support a dynamic interaction between two fundamental modes of epigenetic repression during postnatal maturation of excitatory neurons, which together confer robustness on neuronal regulation.
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Affiliation(s)
- Junhao Li
- Department of Cognitive Science, University of California, San DiegoLa JollaUnited States
| | - Antonio Pinto-Duarte
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Mark Zander
- Genomic Analysis Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Michael S Cuoco
- Bioinformatics and Systems Biology Graduate Program, University of California, San DiegoLa JollaUnited States
| | - Chi-Yu Lai
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Julia Osteen
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Linjing Fang
- Waitt Advanced Biophotonics Core, Salk Institute for Biological StudiesLa JollaUnited States
| | - Chongyuan Luo
- Genomic Analysis Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
- Howard Hughes Medical Institute, Salk Institute for Biological StudiesLa JollaUnited States
| | - Jacinta D Lucero
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Rosa Gomez-Castanon
- Genomic Analysis Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Joseph R Nery
- Genomic Analysis Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
- Howard Hughes Medical Institute, Salk Institute for Biological StudiesLa JollaUnited States
| | - Isai Silva-Garcia
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Yan Pang
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Terrence J Sejnowski
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Susan B Powell
- Department of Psychiatry, University of California, San DiegoLa JollaUnited States
| | - Joseph R Ecker
- Genomic Analysis Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
| | - Eran A Mukamel
- Department of Cognitive Science, University of California, San DiegoLa JollaUnited States
| | - M Margarita Behrens
- Computational Neurobiology Laboratory, Salk Institute for Biological StudiesLa JollaUnited States
- Department of Psychiatry, University of California, San DiegoLa JollaUnited States
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22
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Hypermethylation of PDX1, EN2, and MSX1 predicts the prognosis of colorectal cancer. Exp Mol Med 2022; 54:156-168. [PMID: 35169223 PMCID: PMC8894425 DOI: 10.1038/s12276-022-00731-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/12/2021] [Accepted: 11/18/2021] [Indexed: 02/06/2023] Open
Abstract
Despite numerous observations regarding the relationship between DNA methylation changes and cancer progression, only a few genes have been verified as diagnostic biomarkers of colorectal cancer (CRC). To more practically detect methylation changes, we performed targeted bisulfite sequencing. Through co-analysis of RNA-seq, we identified cohort-specific DNA methylation markers: CpG islands of the intragenic regions of PDX1, EN2, and MSX1. We validated that these genes have oncogenic features in CRC and that their expression levels are increased in correlation with the hypermethylation of intragenic regions. The reliable depth of the targeted bisulfite sequencing data enabled us to design highly optimized quantitative methylation-specific PCR primer sets that can successfully detect subtle changes in the methylation levels of candidate regions. Furthermore, these methylation levels can divide CRC patients into two groups denoting good and poor prognoses. In this study, we present a streamlined workflow for screening clinically significant differentially methylated regions. Our discovery of methylation markers in the PDX1, EN2, and MSX1 genes suggests their promising performance as prognostic markers and their clinical application in CRC patients. An experimental strategy for detecting patterns of DNA modification reveals gene-specific alterations associated with worse outcomes in colorectal cancer patients. Many genomic regions undergo a process of chemical modification called methylation, which can strongly affect the expression of nearby genes. Many cancers exhibit abnormal methylation, and South Korean researchers led by Tae-You Kim of Seoul National University and Lark Kyun Kim of Yonsei University College of Medicine, Seoul, have developed a strategy for identifying such tumor-specific modifications. They identified a trio of genes that undergo excessive methylation in colorectal cancer, and show that this ‘signature’ is associated with more advanced metastatic tumors and shorter overall survival. The results from this study could give clinicians an additional diagnostic tool, and highlight the potential utility of performing such methylation profiling in other cancer types.
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23
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Proteins That Read DNA Methylation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:269-293. [DOI: 10.1007/978-3-031-11454-0_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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24
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Ayaz G, Turan G, Olgun ÇE, Kars G, Karakaya B, Yavuz K, Demiralay ÖD, Can T, Muyan M, Yaşar P. A prelude to the proximity interaction mapping of CXXC5. Sci Rep 2021; 11:17587. [PMID: 34475492 PMCID: PMC8413330 DOI: 10.1038/s41598-021-97060-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 08/17/2021] [Indexed: 11/09/2022] Open
Abstract
CXXC5 is a member of the zinc-finger CXXC family proteins that interact with unmodified CpG dinucleotides through a conserved ZF-CXXC domain. CXXC5 is involved in the modulation of gene expressions that lead to alterations in diverse cellular events. However, the underlying mechanism of CXXC5-modulated gene expressions remains unclear. Proteins perform their functions in a network of proteins whose identities and amounts change spatiotemporally in response to various stimuli in a lineage-specific manner. Since CXXC5 lacks an intrinsic transcription regulatory function or enzymatic activity but is a DNA binder, CXXC5 by interacting with proteins could act as a scaffold to establish a chromatin state restrictive or permissive for transcription. To initially address this, we utilized the proximity-dependent biotinylation approach. Proximity interaction partners of CXXC5 include DNA and chromatin modifiers, transcription factors/co-regulators, and RNA processors. Of these, CXXC5 through its CXXC domain interacted with EMD, MAZ, and MeCP2. Furthermore, an interplay between CXXC5 and MeCP2 was critical for a subset of CXXC5 target gene expressions. It appears that CXXC5 may act as a nucleation factor in modulating gene expressions. Providing a prelude for CXXC5 actions, our results could also contribute to a better understanding of CXXC5-mediated cellular processes in physiology and pathophysiology.
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Affiliation(s)
- Gamze Ayaz
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey. .,Cancer and Stem Cell Epigenetics Section, Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Gizem Turan
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Çağla Ece Olgun
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Gizem Kars
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Burcu Karakaya
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Kerim Yavuz
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Öykü Deniz Demiralay
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Tolga Can
- Department of Computer Engineering Middle, East Technical University, 06800, Ankara, Turkey
| | - Mesut Muyan
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey. .,Cansyl Laboratories, Middle East Technical University, 06800, Ankara, Turkey.
| | - Pelin Yaşar
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey.,Epigenetics and Stem Cell Biology Laboratory, Single Cell Dynamics Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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25
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Huang J, Zhang F, Su M, Li J, Yi W, Hou L, Yang S, Liu J, Zhang H, Ma T, Wu D. MeCP2 prevents age-associated cognitive decline via restoring synaptic plasticity in a senescence-accelerated mouse model. Aging Cell 2021; 20:e13451. [PMID: 34363729 PMCID: PMC8441320 DOI: 10.1111/acel.13451] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/02/2021] [Accepted: 07/20/2021] [Indexed: 12/17/2022] Open
Abstract
Age‐related cognitive decline in neurodegenerative diseases, such as Alzheimer's disease (AD), is associated with the deficits of synaptic plasticity. Therefore, exploring promising targets to enhance synaptic plasticity in neurodegenerative disorders is crucial. It has been demonstrated that methyl‐CpG binding protein 2 (MeCP2) plays a vital role in neuronal development and MeCP2 malfunction causes various neurodevelopmental disorders. However, the role of MeCP2 in neurodegenerative diseases has been less reported. In the study, we found that MeCP2 expression in the hippocampus was reduced in the hippocampus of senescence‐accelerated mice P8 (SAMP8) mice. Overexpression of hippocampal MeCP2 could elevate synaptic plasticity and cognitive function in SAMP8 mice, while knockdown of MeCP2 impaired synaptic plasticity and cognitive function in senescence accelerated‐resistant 1 (SAMR1) mice. MeCP2‐mediated regulation of synaptic plasticity may be associated with CREB1 pathway. These results suggest that MeCP2 plays a vital role in age‐related cognitive decline by regulating synaptic plasticity and indicate that MeCP2 may be promising targets for the treatment of age‐related cognitive decline in neurodegenerative diseases.
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Affiliation(s)
- Jin‐Lan Huang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
| | - Fan Zhang
- Scientific research center of traditional Chinese medicine Guangxi University of Chinese Medicine Nanning China
| | - Min Su
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
| | - Jiaxin Li
- Institute for Stem Cell and Neural Regeneration School of Pharmacy Nanjing Medical University Nanjing China
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine School of Pharmacy Nanjing Medical University Nanjing China
| | - Wen Yi
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
| | - Li‐Xiang Hou
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
| | - Si‐Man Yang
- Scientific research center of traditional Chinese medicine Guangxi University of Chinese Medicine Nanning China
| | - Jin‐Yuan Liu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
| | - Hao‐An Zhang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
| | - Tengfei Ma
- Institute for Stem Cell and Neural Regeneration School of Pharmacy Nanjing Medical University Nanjing China
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine School of Pharmacy Nanjing Medical University Nanjing China
| | - Deng‐Pan Wu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy School of Xuzhou Medical University Xuzhou China
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26
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Sinha P, Rani A, Kumar A, Riva A, Brant JO, Foster TC. Examination of CA1 Hippocampal DNA Methylation as a Mechanism for Closing of Estrogen's Critical Window. Front Aging Neurosci 2021; 13:717032. [PMID: 34421577 PMCID: PMC8371553 DOI: 10.3389/fnagi.2021.717032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/15/2021] [Indexed: 02/01/2023] Open
Abstract
There is a critical window for estrogen replacement therapy, beyond which estradiol (E2) fails to enhance cognition and N-methyl-D-aspartate (NMDA) receptor function, and E2-responsive transcription decreases. Much less attention has been given to the mechanism for closing of the critical window, which is thought to involve the decline in estrogen signaling cascades, possibly involving epigenetic mechanisms, including DNA methylation. This study investigated changes in DNA methylation in region CA1 of the hippocampus of ovariectomized female rats over the course of brain aging and in response to E2-treatment, using whole genome bisulfite sequencing. Differential methylation of CpG and non-CpG (CHG and CHH) sites and associated genes were characterized in aged controls (AC), middle-age controls (MC), and young controls (YC) and differential methylation in response to E2-treatment (T) was examined in each age group (AT-AC, MT-MC, and YT-YC). Possible candidate genes for the closing of the critical window were defined as those that were hypomethylated by E2-treatment in younger animals, but were unresponsive in aged animals. Gene ontology categories for possible critical window genes were linked to response to hormones (Adcyap1, Agtr2, Apob, Ahr, Andpro, Calm2, Cyp4a2, Htr1b, Nr3c2, Pitx2, Pth, Pdk4, Slc2a2, Tnc, and Wnt5a), including G-protein receptor signaling (Gpr22 and Rgs4). Other possible critical window genes were linked to glutamate synapses (Nedd4, Grm1, Grm7, and Grin3a). These results suggest that decreased E2 signaling with advanced age, and/or prolonged E2 deprivation, results in methylation of E2-responsive genes, including those involved in rapid E2 signaling, which may limit subsequent transcription.
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Affiliation(s)
- Puja Sinha
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Alberto Riva
- Bioinformatics Core, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - Jason Orr Brant
- Department of Biostatistics, University of Florida, Gainesville, FL, United States
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Genetics and Genomics Program, University of Florida, Gainesville, FL, United States
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27
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Ibrahim A, Papin C, Mohideen-Abdul K, Le Gras S, Stoll I, Bronner C, Dimitrov S, Klaholz BP, Hamiche A. MeCP2 is a microsatellite binding protein that protects CA repeats from nucleosome invasion. Science 2021; 372:372/6549/eabd5581. [PMID: 34324427 DOI: 10.1126/science.abd5581] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 05/06/2021] [Indexed: 12/14/2022]
Abstract
The Rett syndrome protein MeCP2 was described as a methyl-CpG-binding protein, but its exact function remains unknown. Here we show that mouse MeCP2 is a microsatellite binding protein that specifically recognizes hydroxymethylated CA repeats. Depletion of MeCP2 alters chromatin organization of CA repeats and lamina-associated domains and results in nucleosome accumulation on CA repeats and genome-wide transcriptional dysregulation. The structure of MeCP2 in complex with a hydroxymethylated CA repeat reveals a characteristic DNA shape, with considerably modified geometry at the 5-hydroxymethylcytosine, which is recognized specifically by Arg133, a key residue whose mutation causes Rett syndrome. Our work identifies MeCP2 as a microsatellite DNA binding protein that targets the 5hmC-modified CA-rich strand and maintains genome regions nucleosome-free, suggesting a role for MeCP2 dysfunction in Rett syndrome.
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Affiliation(s)
- Abdulkhaleg Ibrahim
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France.,Department of Functional Genomics and Cancer, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,Biotechnology Research Center (BTRC), 30303 Tripoli, Libya
| | - Christophe Papin
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France.,Department of Functional Genomics and Cancer, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Kareem Mohideen-Abdul
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France
| | - Stéphanie Le Gras
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Isabelle Stoll
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France.,Department of Functional Genomics and Cancer, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Christian Bronner
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France.,Department of Functional Genomics and Cancer, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Stefan Dimitrov
- Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Institute for Advanced Biosciences (IAB), Site Santé - Allée des Alpes, 38700 La Tronche, France. .,Roumen Tsanev Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Bruno P Klaholz
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France. .,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France
| | - Ali Hamiche
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 67400 Illkirch, France. .,Department of Functional Genomics and Cancer, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch, France.,Center of Excellence in Bionanoscience Research, King Abdulaziz University (KAU), Jeddah 21589, Saudi Arabia
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28
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Transcriptomic and Epigenomic Landscape in Rett Syndrome. Biomolecules 2021; 11:biom11070967. [PMID: 34209228 PMCID: PMC8301932 DOI: 10.3390/biom11070967] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 12/13/2022] Open
Abstract
Rett syndrome (RTT) is an extremely invalidating, cureless, developmental disorder, and it is considered one of the leading causes of intellectual disability in female individuals. The vast majority of RTT cases are caused by de novo mutations in the X-linked Methyl-CpG binding protein 2 (MECP2) gene, which encodes a multifunctional reader of methylated DNA. MeCP2 is a master epigenetic modulator of gene expression, with a role in the organization of global chromatin architecture. Based on its interaction with multiple molecular partners and the diverse epigenetic scenario, MeCP2 triggers several downstream mechanisms, also influencing the epigenetic context, and thus leading to transcriptional activation or repression. In this frame, it is conceivable that defects in such a multifaceted factor as MeCP2 lead to large-scale alterations of the epigenome, ranging from an unbalanced deposition of epigenetic modifications to a transcriptional alteration of both protein-coding and non-coding genes, with critical consequences on multiple downstream biological processes. In this review, we provide an overview of the current knowledge concerning the transcriptomic and epigenomic alterations found in RTT patients and animal models.
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29
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Zocher S, Overall RW, Lesche M, Dahl A, Kempermann G. Environmental enrichment preserves a young DNA methylation landscape in the aged mouse hippocampus. Nat Commun 2021; 12:3892. [PMID: 34162876 PMCID: PMC8222384 DOI: 10.1038/s41467-021-23993-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 05/20/2021] [Indexed: 02/05/2023] Open
Abstract
The decline of brain function during aging is associated with epigenetic changes, including DNA methylation. Lifestyle interventions can improve brain function during aging, but their influence on age-related epigenetic changes is unknown. Using genome-wide DNA methylation sequencing, we here show that experiencing a stimulus-rich environment counteracts age-related DNA methylation changes in the hippocampal dentate gyrus of mice. Specifically, environmental enrichment prevented the aging-induced CpG hypomethylation at target sites of the methyl-CpG-binding protein Mecp2, which is critical to neuronal function. The genes at which environmental enrichment counteracted aging effects have described roles in neuronal plasticity, neuronal cell communication and adult hippocampal neurogenesis and are dysregulated with age-related cognitive decline in the human brain. Our results highlight the stimulating effects of environmental enrichment on hippocampal plasticity at the level of DNA methylation and give molecular insights into the specific aspects of brain aging that can be counteracted by lifestyle interventions.
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Affiliation(s)
- Sara Zocher
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
| | - Rupert W Overall
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
| | - Mathias Lesche
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- DRESDEN-concept Genome Center c/o Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Andreas Dahl
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- DRESDEN-concept Genome Center c/o Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany.
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany.
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30
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Wang G, Li Y, Yang G, Yang T, He L, Wang Y. Cathelicidin antimicrobial peptide (CAMP) gene promoter methylation induces chondrocyte apoptosis. Hum Genomics 2021; 15:24. [PMID: 33892795 PMCID: PMC8063489 DOI: 10.1186/s40246-021-00321-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/25/2021] [Indexed: 12/03/2022] Open
Abstract
Objective The occurrence of osteoarthritis is related to genetic and environmental factors. Among them, the change of chondrocyte gene expression pattern regulated by epigenetic modification is an important participant. This study analyzed the effect of CAMP gene methylation on the level of oxidative stress and inflammation of chondrocytes. Methods We analyzed the changes of the transcriptome in the articular cartilage tissue of osteoarthritis (OA) patients from the GSE117999 dataset. The GSE48422 dataset was used to analyze the changes in the methylation level of osteoarthritis cells. Cell Counting Kit-8 (CCK-8) and flow cytometry analysis of short hairpin RNA (shRNA) silencing CAMP gene and 5-μM 5-Aza-2’-Deoxycytidine (AZA) treatment on the proliferation and apoptosis of Human chondrocytes osteoarthritis (HC-OA) cells. The Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was used to detect the level of reactive oxygen species (ROS), and the expression level of inflammatory factors was analyzed by Western Blot. Results The expression of CAMP in cartilage tissue of OA patients was upregulated, and the level of methylation was downregulated. CAMP was highly expressed in osteoarthritis articular cartilage cells. Silencing CAMP inhibited the proliferation of HC-OA cells and promoted their apoptosis. CAMP gene methylation inhibited ROS levels and tumor necrosis factor-α (TNF-α) expression levels in HC-OA cells, and promoted transforming growth factor beta (TGF-β) expression. CAMP gene methylation inhibited the proliferation of HC-OA cells and promoted their apoptosis. Conclusion CAMP gene promoter methylation inhibits ROS levels and inflammation and induces chondrocyte apoptosis.
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Affiliation(s)
- Guoliang Wang
- Department of Sports Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, 650031, Yunnan, China
| | - Yanlin Li
- Department of Sports Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, 650031, Yunnan, China
| | - Guang Yang
- Department of Sports Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, 650031, Yunnan, China
| | - Tengyun Yang
- Department of Sports Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, 650031, Yunnan, China
| | - Lu He
- Department of Sports Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, 650031, Yunnan, China
| | - Yang Wang
- Department of Sports Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, 650031, Yunnan, China.
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Mozolewski P, Jeziorek M, Schuster CM, Bading H, Frost B, Dobrowolski R. The role of nuclear Ca2+ in maintaining neuronal homeostasis and brain health. J Cell Sci 2021; 134:jcs254904. [PMID: 33912918 PMCID: PMC8084578 DOI: 10.1242/jcs.254904] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nuclear Ca2+ has emerged as one of the most potent mediators of the dialogue between neuronal synapses and the nucleus that regulates heterochromatin states, transcription factor activity, nuclear morphology and neuronal gene expression induced by synaptic activity. Recent studies underline the importance of nuclear Ca2+ signaling in long-lasting, activity-induced adaptation and maintenance of proper brain function. Diverse forms of neuroadaptation require transient nuclear Ca2+ signaling and cyclic AMP-responsive element-binding protein (CREB1, referred to here as CREB) as its prime target, which works as a tunable switch to drive and modulate specific gene expression profiles associated with memory, pain, addiction and neuroprotection. Furthermore, a reduction of nuclear Ca2+ levels has been shown to be neurotoxic and a causal factor driving the progression of neurodegenerative disorders, as well as affecting neuronal autophagy. Because of its central role in the brain, deficits in nuclear Ca2+ signaling may underlie a continuous loss of neuroprotection in the aging brain, contributing to the pathophysiology of Alzheimer's disease. In this Review, we discuss the principles of the 'nuclear calcium hypothesis' in the context of human brain function and its role in controlling diverse forms of neuroadaptation and neuroprotection. Furthermore, we present the most relevant and promising perspectives for future studies.
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Affiliation(s)
- Pawel Mozolewski
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Maciej Jeziorek
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Christoph M. Schuster
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, INF 345 and INF 366, 69120 Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, INF 345 and INF 366, 69120 Heidelberg, Germany
| | - Bess Frost
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health, San Antonio, San Antonio, TX 78229, USA
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, University of Texas Health, San Antonio, San Antonio, TX 78229, USA
| | - Radek Dobrowolski
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health, San Antonio, San Antonio, TX 78229, USA
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Tillotson R, Cholewa-Waclaw J, Chhatbar K, Connelly JC, Kirschner SA, Webb S, Koerner MV, Selfridge J, Kelly DA, De Sousa D, Brown K, Lyst MJ, Kriaucionis S, Bird A. Neuronal non-CG methylation is an essential target for MeCP2 function. Mol Cell 2021; 81:1260-1275.e12. [PMID: 33561390 PMCID: PMC7980222 DOI: 10.1016/j.molcel.2021.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/17/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
DNA methylation is implicated in neuronal biology via the protein MeCP2, the mutation of which causes Rett syndrome. MeCP2 recruits the NCOR1/2 co-repressor complexes to methylated cytosine in the CG dinucleotide, but also to sites of non-CG methylation, which are abundant in neurons. To test the biological significance of the dual-binding specificity of MeCP2, we replaced its DNA binding domain with an orthologous domain from MBD2, which can only bind mCG motifs. Knockin mice expressing the domain-swap protein displayed severe Rett-syndrome-like phenotypes, indicating that normal brain function requires the interaction of MeCP2 with sites of non-CG methylation, specifically mCAC. The results support the notion that the delayed onset of Rett syndrome is due to the simultaneous post-natal accumulation of mCAC and its reader MeCP2. Intriguingly, genes dysregulated in both Mecp2 null and domain-swap mice are implicated in other neurological disorders, potentially highlighting targets of relevance to the Rett syndrome phenotype.
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Affiliation(s)
- Rebekah Tillotson
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Justyna Cholewa-Waclaw
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kashyap Chhatbar
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - John C Connelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Sophie A Kirschner
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Martha V Koerner
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Jim Selfridge
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - David A Kelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Dina De Sousa
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kyla Brown
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Matthew J Lyst
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Skirmantas Kriaucionis
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK.
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33
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D'Mello SR. MECP2 and the Biology of MECP2 Duplication Syndrome. J Neurochem 2021; 159:29-60. [PMID: 33638179 DOI: 10.1111/jnc.15331] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 02/18/2021] [Indexed: 11/27/2022]
Abstract
MECP2 duplication syndrome (MDS), a rare X-linked genomic disorder affecting predominantly males, is caused by duplication of the chromosomal region containing the methyl CpG binding protein-2 (MECP2) gene, which encodes methyl-CpG-binding protein 2 (MECP2), a multi-functional protein required for proper brain development and maintenance of brain function during adulthood. Disease symptoms include severe motor and cognitive impairment, delayed or absent speech development, autistic features, seizures, ataxia, recurrent respiratory infections and shortened lifespan. The cellular and molecular mechanisms by which a relatively modest increase in MECP2 protein causes such severe disease symptoms are poorly understood and consequently there are no treatments available for this fatal disorder. This review summarizes what is known to date about the structure and complex regulation of MECP2 and its many functions in the developing and adult brain. Additionally, recent experimental findings on the cellular and molecular underpinnings of MDS based on cell culture and mouse models of the disorder are reviewed. The emerging picture from these studies is that MDS is a neurodegenerative disorder in which neurons die in specific parts of the central nervous system, including the cortex, hippocampus, cerebellum and spinal cord. Neuronal death likely results from astrocytic dysfunction, including a breakdown of glutamate homeostatic mechanisms. The role of elevations in the expression of glial acidic fibrillary protein (GFAP) in astrocytes and the microtubule-associated protein, Tau, in neurons to the pathogenesis of MDS is discussed. Lastly, potential therapeutic strategies to potentially treat MDS are discussed.
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34
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An all-to-all approach to the identification of sequence-specific readers for epigenetic DNA modifications on cytosine. Nat Commun 2021; 12:795. [PMID: 33542217 PMCID: PMC7862700 DOI: 10.1038/s41467-021-20950-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/14/2020] [Indexed: 12/31/2022] Open
Abstract
Epigenetic modifications of DNA play important roles in many biological processes. Identifying readers of these epigenetic marks is a critical step towards understanding the underlying mechanisms. Here, we present an all-to-all approach, dubbed digital affinity profiling via proximity ligation (DAPPL), to simultaneously profile human TF-DNA interactions using mixtures of random DNA libraries carrying different epigenetic modifications (i.e., 5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine) on CpG dinucleotides. Many proteins that recognize consensus sequences carrying these modifications in symmetric and/or hemi-modified forms are identified. We further demonstrate that the modifications in different sequence contexts could either enhance or suppress TF binding activity. Moreover, many modifications can affect TF binding specificity. Furthermore, symmetric modifications show a stronger effect in either enhancing or suppressing TF-DNA interactions than hemi-modifications. Finally, in vivo evidence suggests that USF1 and USF2 might regulate transcription via hydroxymethylcytosine-binding activity in weak enhancers in human embryonic stem cells. Identifying readers of epigenetic marks is a critical step for understanding the role of epigenetic marks in biology. Here, the authors applied DAPPL, an all-to-all approach to profile the interactions between TFs and epigenetic modified DNA libraries.
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35
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Marco A, Meharena HS, Dileep V, Raju RM, Davila-Velderrain J, Zhang AL, Adaikkan C, Young JZ, Gao F, Kellis M, Tsai LH. Mapping the epigenomic and transcriptomic interplay during memory formation and recall in the hippocampal engram ensemble. Nat Neurosci 2020; 23:1606-1617. [PMID: 33020654 PMCID: PMC7686266 DOI: 10.1038/s41593-020-00717-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 09/01/2020] [Indexed: 12/22/2022]
Abstract
The epigenome and three-dimensional (3D) genomic architecture are emerging as key factors in the dynamic regulation of different transcriptional programs required for neuronal functions. In this study, we used an activity-dependent tagging system in mice to determine the epigenetic state, 3D genome architecture and transcriptional landscape of engram cells over the lifespan of memory formation and recall. Our findings reveal that memory encoding leads to an epigenetic priming event, marked by increased accessibility of enhancers without the corresponding transcriptional changes. Memory consolidation subsequently results in spatial reorganization of large chromatin segments and promoter-enhancer interactions. Finally, with reactivation, engram neurons use a subset of de novo long-range interactions, where primed enhancers are brought in contact with their respective promoters to upregulate genes involved in local protein translation in synaptic compartments. Collectively, our work elucidates the comprehensive transcriptional and epigenomic landscape across the lifespan of memory formation and recall in the hippocampal engram ensemble.
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Affiliation(s)
- Asaf Marco
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Hiruy S Meharena
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vishnu Dileep
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ravikiran M Raju
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jose Davila-Velderrain
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Amy Letao Zhang
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Chinnakkaruppan Adaikkan
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jennie Z Young
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Fan Gao
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Manolis Kellis
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
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36
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Christian DL, Wu DY, Martin JR, Moore JR, Liu YR, Clemens AW, Nettles SA, Kirkland NM, Papouin T, Hill CA, Wozniak DF, Dougherty JD, Gabel HW. DNMT3A Haploinsufficiency Results in Behavioral Deficits and Global Epigenomic Dysregulation Shared across Neurodevelopmental Disorders. Cell Rep 2020; 33:108416. [PMID: 33238114 PMCID: PMC7716597 DOI: 10.1016/j.celrep.2020.108416] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 09/17/2020] [Accepted: 10/29/2020] [Indexed: 12/19/2022] Open
Abstract
Mutations in DNA methyltransferase 3A (DNMT3A) have been detected in autism and related disorders, but how these mutations disrupt nervous system function is unknown. Here, we define the effects of DNMT3A mutations associated with neurodevelopmental disease. We show that diverse mutations affect different aspects of protein activity but lead to shared deficiencies in neuronal DNA methylation. Heterozygous DNMT3A knockout mice mimicking DNMT3A disruption in disease display growth and behavioral alterations consistent with human phenotypes. Strikingly, in these mice, we detect global disruption of neuron-enriched non-CG DNA methylation, a binding site for the Rett syndrome protein MeCP2. Loss of this methylation leads to enhancer and gene dysregulation that overlaps with models of Rett syndrome and autism. These findings define the effects of DNMT3A haploinsufficiency in the brain and uncover disruption of the non-CG methylation pathway as a convergence point across neurodevelopmental disorders.
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Affiliation(s)
- Diana L Christian
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Dennis Y Wu
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Jenna R Martin
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - J Russell Moore
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Yiran R Liu
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Adam W Clemens
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Sabin A Nettles
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Nicole M Kirkland
- Department of Pathology and Anatomical Science, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Cheryl A Hill
- Department of Pathology and Anatomical Science, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - David F Wozniak
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110-1093, USA; Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110-1093, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Joseph D Dougherty
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110-1093, USA; Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Harrison W Gabel
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA.
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37
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Clemens AW, Gabel HW. Emerging Insights into the Distinctive Neuronal Methylome. Trends Genet 2020; 36:816-832. [PMID: 32839016 PMCID: PMC7572801 DOI: 10.1016/j.tig.2020.07.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 12/20/2022]
Abstract
The genomes of mammalian neurons are enriched for unique forms of DNA methylation, including exceptionally high levels of non-CG methylation. Here, we review recent studies defining how non-CG methylation accumulates in neurons and is read out by the critical regulator of neuronal transcription, MeCP2. We discuss the role of gene expression and genome architecture in establishing non-CG methylation and highlight emerging mechanistic insights into how non-CG methylation and MeCP2 control transcription. Further, we describe the cell type-specific functions of this methylation and explore growing evidence that disruption of this regulatory pathway contributes to neurodevelopmental disorders. These findings uncover how the distinctive epigenome in neurons facilitates the development and function of the complex mammalian brain.
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Affiliation(s)
- Adam W Clemens
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO 63110-1093, USA
| | - Harrison W Gabel
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO 63110-1093, USA.
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38
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Chhatbar K, Cholewa-Waclaw J, Shah R, Bird A, Sanguinetti G. Quantitative analysis questions the role of MeCP2 as a global regulator of alternative splicing. PLoS Genet 2020; 16:e1009087. [PMID: 33048927 PMCID: PMC7584252 DOI: 10.1371/journal.pgen.1009087] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/23/2020] [Accepted: 08/28/2020] [Indexed: 11/19/2022] Open
Abstract
MeCP2 is an abundant protein in mature nerve cells, where it binds to DNA sequences containing methylated cytosine. Mutations in the MECP2 gene cause the severe neurological disorder Rett syndrome (RTT), provoking intensive study of the underlying molecular mechanisms. Multiple functions have been proposed, one of which involves a regulatory role in splicing. Here we leverage the recent availability of high-quality transcriptomic data sets to probe quantitatively the potential influence of MeCP2 on alternative splicing. Using a variety of machine learning approaches that can capture both linear and non-linear associations, we show that widely different levels of MeCP2 have a minimal effect on alternative splicing in three different systems. Alternative splicing was also apparently indifferent to developmental changes in DNA methylation levels. Our results suggest that regulation of splicing is not a major function of MeCP2. They also highlight the importance of multi-variate quantitative analyses in the formulation of biological hypotheses.
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Affiliation(s)
- Kashyap Chhatbar
- School of Informatics, University of Edinburgh, Edinburgh, United Kingdom
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Justyna Cholewa-Waclaw
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Ruth Shah
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Guido Sanguinetti
- School of Informatics, University of Edinburgh, Edinburgh, United Kingdom
- International School for Advanced Studies (SISSA), Trieste, Italy
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39
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Connelly JC, Cholewa-Waclaw J, Webb S, Steccanella V, Waclaw B, Bird A. Absence of MeCP2 binding to non-methylated GT-rich sequences in vivo. Nucleic Acids Res 2020; 48:3542-3552. [PMID: 32064528 PMCID: PMC7144902 DOI: 10.1093/nar/gkaa102] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/18/2020] [Accepted: 02/13/2020] [Indexed: 12/16/2022] Open
Abstract
MeCP2 is a nuclear protein that binds to sites of cytosine methylation in the genome. While most evidence confirms this epigenetic mark as the primary determinant of DNA binding, MeCP2 is also reported to have an affinity for non-methylated DNA sequences. Here we investigated the molecular basis and in vivo significance of its reported affinity for non-methylated GT-rich sequences. We confirmed this interaction with isolated domains of MeCP2 in vitro and defined a minimal target DNA sequence. Binding depends on pyrimidine 5′ methyl groups provided by thymine and requires adjacent guanines and a correctly orientated A/T-rich flanking sequence. Unexpectedly, full-length MeCP2 protein failed to bind GT-rich sequences in vitro. To test for MeCP2 binding to these motifs in vivo, we analysed human neuronal cells using ChIP-seq and ATAC-seq technologies. While both methods robustly detected DNA methylation-dependent binding of MeCP2 to mCG and mCAC, neither showed evidence of MeCP2 binding to GT-rich motifs. The data suggest that GT binding is an in vitro phenomenon without in vivo relevance. Our findings argue that MeCP2 does not read unadorned DNA sequence and therefore support the notion that its primary role is to interpret epigenetic modifications of DNA.
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Affiliation(s)
- John C Connelly
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | | | - Shaun Webb
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | - Verdiana Steccanella
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | - Bartlomiej Waclaw
- School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh, UK
| | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
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40
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Cheema MS, Good KV, Kim B, Soufari H, O’Sullivan C, Freeman ME, Stefanelli G, Casas CR, Zengeler KE, Kennedy AJ, Eirin Lopez JM, Howard PL, Zovkic IB, Shabanowitz J, Dryhurst DD, Hunt DF, Mackereth CD, Ausió J. Deciphering the Enigma of the Histone H2A.Z-1/H2A.Z-2 Isoforms: Novel Insights and Remaining Questions. Cells 2020; 9:cells9051167. [PMID: 32397240 PMCID: PMC7290884 DOI: 10.3390/cells9051167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/20/2022] Open
Abstract
The replication independent (RI) histone H2A.Z is one of the more extensively studied variant members of the core histone H2A family, which consists of many replication dependent (RD) members. The protein has been shown to be indispensable for survival, and involved in multiple roles from DNA damage to chromosome segregation, replication, and transcription. However, its functional involvement in gene expression is controversial. Moreover, the variant in several groups of metazoan organisms consists of two main isoforms (H2A.Z-1 and H2A.Z-2) that differ in a few (3–6) amino acids. They comprise the main topic of this review, starting from the events that led to their identification, what is currently known about them, followed by further experimental, structural, and functional insight into their roles. Despite their structural differences, a direct correlation to their functional variability remains enigmatic. As all of this is being elucidated, it appears that a strong functional involvement of isoform variability may be connected to development.
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Affiliation(s)
- Manjinder S. Cheema
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Katrina V. Good
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Bohyun Kim
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Heddy Soufari
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, 2 rue Robert Escarpit, F-33607 Pessac, France; (H.S.); (C.D.M.)
- Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Connor O’Sullivan
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Melissa E. Freeman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Gilda Stefanelli
- Department of Neurosciences & Mental Health, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (G.S.); (I.B.Z.)
| | - Ciro Rivera Casas
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International UniversityNorth Miami, FL 33181, USA; (C.R.C.); (J.M.E.L.)
| | - Kristine E. Zengeler
- Department of Chemistry and Biochemistry, Bates College, 2 Andrews Road, Lewiston, ME 04240, USA; (K.E.Z.); (A.J.K.)
| | - Andrew J. Kennedy
- Department of Chemistry and Biochemistry, Bates College, 2 Andrews Road, Lewiston, ME 04240, USA; (K.E.Z.); (A.J.K.)
| | - Jose Maria Eirin Lopez
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International UniversityNorth Miami, FL 33181, USA; (C.R.C.); (J.M.E.L.)
| | - Perry L. Howard
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Iva B. Zovkic
- Department of Neurosciences & Mental Health, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (G.S.); (I.B.Z.)
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; (J.S.); (D.F.H.)
| | - Deanna D. Dryhurst
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Donald F. Hunt
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; (J.S.); (D.F.H.)
- Department of Pathology, University of Virginia, Charlottesville, VA 22903, USA
| | - Cameron D. Mackereth
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, 2 rue Robert Escarpit, F-33607 Pessac, France; (H.S.); (C.D.M.)
- Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
- Correspondence: ; Tel.: +1-250-721-8863; Fax: +1-250-721-8855
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41
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Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
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Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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42
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Tillotson R, Bird A. The Molecular Basis of MeCP2 Function in the Brain. J Mol Biol 2020; 432:1602-1623. [PMID: 31629770 DOI: 10.1016/j.jmb.2019.10.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/14/2022]
Abstract
MeCP2 is a reader of the DNA methylome that occupies a large proportion of the genome due to its high abundance and the frequency of its target sites. It has been the subject of extensive study because of its link with 'MECP2-related disorders', of which Rett syndrome is the most prevalent. This review integrates evidence from patient mutation data with results of experimental studies using mouse models, cell lines and in vitro systems to critically evaluate our understanding of MeCP2 protein function. Recent evidence challenges the idea that MeCP2 is a multifunctional hub that integrates diverse processes to underpin neuronal function, suggesting instead that its primary role is to recruit the NCoR1/2 co-repressor complex to methylated sites in the genome, leading to dampening of gene expression.
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Affiliation(s)
- Rebekah Tillotson
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada; Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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43
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Affinity for DNA Contributes to NLS Independent Nuclear Localization of MeCP2. Cell Rep 2020; 24:2213-2220. [PMID: 30157418 PMCID: PMC6130050 DOI: 10.1016/j.celrep.2018.07.099] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 06/22/2018] [Accepted: 07/26/2018] [Indexed: 12/14/2022] Open
Abstract
MeCP2 is a nuclear protein that is mutated in the severe neurological disorder Rett syndrome (RTT). The ability to target β-galactosidase to the nucleus was previously used to identify a conserved nuclear localization signal (NLS) in MeCP2 that interacts with the nuclear import factors KPNA3 and KPNA4. Here, we report that nuclear localization of MeCP2 does not depend on its NLS. Instead, our data reveal that an intact methyl-CpG binding domain (MBD) is sufficient for nuclear localization, suggesting that MeCP2 can be retained in the nucleus by its affinity for DNA. Consistent with these findings, we demonstrate that disease progression in a mouse model of RTT is unaffected by an inactivating mutation in the NLS of MeCP2. Taken together, our work reveals an unexpected redundancy between functional domains of MeCP2 in targeting this protein to the nucleus, potentially explaining why NLS-inactivating mutations are rarely associated with disease. Nuclear localization of MeCP2 does not require its NLS DNA binding by MeCP2 contributes to its NLS-independent nuclear localization MeCP2 NLS mutation does not affect pathology in a mouse model of Rett syndrome
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44
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Clemens AW, Wu DY, Moore JR, Christian DL, Zhao G, Gabel HW. MeCP2 Represses Enhancers through Chromosome Topology-Associated DNA Methylation. Mol Cell 2020; 77:279-293.e8. [PMID: 31784360 PMCID: PMC6980697 DOI: 10.1016/j.molcel.2019.10.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 09/05/2019] [Accepted: 10/23/2019] [Indexed: 01/28/2023]
Abstract
The genomes of mammalian neurons contain uniquely high levels of non-CG DNA methylation that can be bound by the Rett syndrome protein, MeCP2, to regulate gene expression. How patterns of non-CG methylation are established in neurons and the mechanism by which this methylation works with MeCP2 to control gene expression is unclear. Here, we find that genes repressed by MeCP2 are often located within megabase-scale regions of high non-CG methylation that correspond with topologically associating domains of chromatin folding. MeCP2 represses enhancers found in these domains that are enriched for non-CG and CG methylation, with the strongest repression occurring for enhancers located within MeCP2-repressed genes. These alterations in enhancer activity provide a mechanism for how MeCP2 disruption in disease can lead to widespread changes in gene expression. Hence, we find that DNA topology can shape non-CG DNA methylation across the genome to dictate MeCP2-mediated enhancer regulation in the brain.
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Affiliation(s)
- Adam W Clemens
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Dennis Y Wu
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - J Russell Moore
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Diana L Christian
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Guoyan Zhao
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Harrison W Gabel
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA.
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45
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Poon CH, Chan YS, Fung ML, Lim LW. Memory and neuromodulation: A perspective of DNA methylation. Neurosci Biobehav Rev 2019; 111:57-68. [PMID: 31846654 DOI: 10.1016/j.neubiorev.2019.12.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/05/2019] [Accepted: 12/13/2019] [Indexed: 02/07/2023]
Abstract
Neuromodulation techniques have shown promising efficacy on memory function and understanding the epigenetic mechanisms contributing to these processes would shed light on the molecular outcomes essential for cognition. In this review, we highlight some epigenetic mechanisms underlying neuromodulation and regulatory effects of neuronal activity-induced DNA methylation on genes that are highly involved in memory formation. Next, we examine the evidence to support DNA methyltransferase 3a, methyl-CpG binding protein 2, and DNA demethylase as possible memory modulation targets. Finally, we report the recent developments in the field of neuromodulation and explore the potential of these techniques for future neuroepigenetic research.
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Affiliation(s)
- Chi Him Poon
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Man Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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46
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Boxer LD, Renthal W, Greben AW, Whitwam T, Silberfeld A, Stroud H, Li E, Yang MG, Kinde B, Griffith EC, Bonev B, Greenberg ME. MeCP2 Represses the Rate of Transcriptional Initiation of Highly Methylated Long Genes. Mol Cell 2019; 77:294-309.e9. [PMID: 31784358 DOI: 10.1016/j.molcel.2019.10.032] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 09/09/2019] [Accepted: 10/23/2019] [Indexed: 12/14/2022]
Abstract
Mutations in the methyl-DNA-binding repressor protein MeCP2 cause the devastating neurodevelopmental disorder Rett syndrome. It has been challenging to understand how MeCP2 regulates transcription because MeCP2 binds broadly across the genome and MeCP2 mutations are associated with widespread small-magnitude changes in neuronal gene expression. We demonstrate here that MeCP2 represses nascent RNA transcription of highly methylated long genes in the brain through its interaction with the NCoR co-repressor complex. By measuring the rates of transcriptional initiation and elongation directly in the brain, we find that MeCP2 has no measurable effect on transcriptional elongation, but instead represses the rate at which Pol II initiates transcription of highly methylated long genes. These findings suggest a new model of MeCP2 function in which MeCP2 binds broadly across highly methylated regions of DNA, but acts at transcription start sites to attenuate transcriptional initiation.
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Affiliation(s)
- Lisa D Boxer
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - William Renthal
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Alexander W Greben
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Tess Whitwam
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Andrew Silberfeld
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Hume Stroud
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Emmy Li
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Marty G Yang
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Benyam Kinde
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Eric C Griffith
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Boyan Bonev
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Michael E Greenberg
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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47
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Li Z, Tan H, Yu H, Deng Z, Zhou X, Wang M. DNA methylation and gene expression profiles characterize epigenetic regulation of lncRNAs in colon adenocarcinoma. J Cell Biochem 2019; 121:2406-2415. [PMID: 31692079 DOI: 10.1002/jcb.29463] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/08/2019] [Indexed: 02/06/2023]
Abstract
The long noncoding RNAs (lncRNAs) are associated with tumorigenesis and progression of cancer. While DNA methylation is a common epigenetic regulator of gene expression, the methylation of lncRNAs was rarely studied. To address this gap, we integrated DNA methylation and RNA-seq data to characterize the landscape of lncRNA methylation in colon adenocarcinoma (COAD). We collected and analyzed the lncRNA expression and methylation data from The Cancer Genome Atlas and Cancer Cell Line Encyclopedia to identify the epigenetically regulated lncRNAs. We further investigated the biological and clinical relevance of the identified lncRNAs via bioinformatics analysis. We identified 20 epigenetically upregulated lncRNAs in COAD, including several well-studied lncRNAs whose methylation regulation were poorly investigated, such as PVT1 and UCA1. We also revealed several novel tumor-associated lncRNAs in COAD, including GATA2-As1 and CYTOR. Next, we explored their biology function using gene set enrichment analysis and competitive endogenous RNA analysis. We characterized the methylation landscape of lncRNA in COAD and identified 20 epigenetically upregulated lncRNAs. Our findings will shed new light on the epigenetic regulation of lncRNA expression by DNA methylation.
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Affiliation(s)
- Zhijin Li
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Hua Tan
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center, Houston, Texas
| | - Hai Yu
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Zhong Deng
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Xiaobo Zhou
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center, Houston, Texas.,Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center, Houston, Texas.,School of Dentistry, The University of Texas Health Science Center, Houston, Texas
| | - Maode Wang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
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48
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Bird A. The Selfishness of Law-Abiding Genes. Trends Genet 2019; 36:8-13. [PMID: 31662191 DOI: 10.1016/j.tig.2019.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/23/2019] [Accepted: 10/01/2019] [Indexed: 12/31/2022]
Abstract
Selfish genes were once controversial, but it is now accepted that the genome contains parasitic elements in addition to a complement of conventional genes. This opinion article argues that 'law-abiding' genes also indulge in game playing to ensure their propagation, so that initially nonessential processes secure a genetic heritage. A gene-centered view of this kind can help to explain otherwise puzzling aspects of biology, including the complexity and stability of living systems.
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Affiliation(s)
- Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, The King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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49
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Zhang C, Huang C, Sui X, Zhong X, Yang W, Hu X, Li Y. Association between gene methylation and HBV infection in hepatocellular carcinoma: A meta-analysis. J Cancer 2019; 10:6457-6465. [PMID: 31772678 PMCID: PMC6856736 DOI: 10.7150/jca.33005] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 08/28/2019] [Indexed: 12/24/2022] Open
Abstract
Gene methylation is an epigenetic alteration in hepatocellular carcinoma (HCC), and hepatitis B virus (HBV) plays a crucial role in carcinogenesis of HCC. However, the association between gene methylation and HBV infection in HCC remains unclear. In our study, we conducted a comprehensive meta-analysis to evaluate the association. A total of 1,148 studies were initially retrieved from some literature database. After a four-step filtration, we obtained 69 case-control studies in this meta-analysis. Our results showed six genes (p16, RASSF1A, GSTP1, APC, p15 and SFRP1) in HBV-positive carcinoma tissues, one gene (GSTP1) in HBV-positive adjacent tissues and two gene (p16 and APC) in HBV-positive carcinoma serums, which were significantly hypermethylated. Subgroup meta-analysis by geographical populations revealed that GSTP1 methylation was significantly higher in HBV-positive carcinoma tissues in China and Japan. In addition, p16 and RASSF1A methylation was significantly higher in China but not in Japan. Our study indicated that HBV infection could induce DNA methylation in HCC and DNA methylation could lead to the development of HBV-related HCC.
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Affiliation(s)
- Cheng Zhang
- Department of Medical Oncology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Changxin Huang
- Department of Medical Oncology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Xinbing Sui
- Department of Medical Oncology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Xueqing Zhong
- Department of Gastroenterology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Wenjun Yang
- Department of Pathology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Xiangrong Hu
- Department of Pathology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yongqiang Li
- Department of Medical Oncology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China.,Key Laboratory of Elemene Class Anti-cancer Chinese Medicine of Zhejiang Province, Hangzhou, Zhejiang, China
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50
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Schlosberg CE, Wu DY, Gabel HW, Edwards JR. ME-Class2 reveals context dependent regulatory roles for 5-hydroxymethylcytosine. Nucleic Acids Res 2019; 47:e28. [PMID: 30649543 PMCID: PMC6412249 DOI: 10.1093/nar/gkz001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 12/04/2018] [Accepted: 01/03/2019] [Indexed: 12/13/2022] Open
Abstract
Since the discovery of 5-hydroxymethylcytosine (5hmC) as a prominent DNA modification found in mammalian genomes, an emergent question has been what role this mark plays in gene regulation. 5hmC is hypothesized to function as an intermediate in the demethylation of 5-methylcytosine (5mC) and in the reactivation of silenced promoters and enhancers. Further, weak positive correlations are observed between gene body 5hmC and gene expression. We previously demonstrated that ME-Class is an effective tool to understand relationships between whole-genome bisulfite sequencing data and expression. In this work, we present ME-Class2, a machine-learning based tool to perform integrative 5mCG, 5hmCG and expression analysis. Using ME-Class2 we analyze whole-genome single-base resolution 5mCG and 5hmCG datasets from 20 primary tissue and cell samples to reveal relationships between 5hmCG and expression. Our analysis indicates that conversion of 5mCG to 5hmCG within 2 kb of the transcription start site associates with distinct functions depending on the summed level of 5mCG + 5hmCG. Unchanged levels of 5mCG + 5hmCG (conversion from 5mCG to stable 5hmCG) associate with repression. Meanwhile, decreases in 5mCG + 5hmCG (5hmCG-mediated demethylation) associate with gene activation. Our results demonstrate that ME-Class2 will prove invaluable to interpret genome-wide 5mC and 5hmC datasets and guide mechanistic studies into the function of 5hmCG.
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Affiliation(s)
- Christopher E Schlosberg
- Center for Pharmacogenomics, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Dennis Y Wu
- Department of Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Harrison W Gabel
- Department of Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - John R Edwards
- Center for Pharmacogenomics, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
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