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Abstract
Epigenetics has enriched human disease studies by adding new interpretations to disease features that cannot be explained by genetic and environmental factors. However, identifying causal mechanisms of epigenetic origin has been challenging. New opportunities have risen from recent findings in intra-individual and cyclical epigenetic variation, which includes circadian epigenetic oscillations. Cytosine modifications display deterministic temporal rhythms, which may drive ageing and complex disease. Temporality in the epigenome, or the 'chrono' dimension, may help the integration of epigenetic, environmental and genetic disease studies, and reconcile several disparities stemming from the arbitrarily delimited research fields. The ultimate goal of chrono-epigenetics is to predict disease risk, age of onset and disease dynamics from within individual-specific temporal dynamics of epigenomes.
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52
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Lim JY, Duttke SH, Baker TS, Lee J, Gambino KJ, Venturini NJ, Ho JSY, Zheng S, Fstkchyan YS, Pillai V, Fajgenbaum DC, Marazzi I, Benner C, Byun M. DNMT3A haploinsufficiency causes dichotomous DNA methylation defects at enhancers in mature human immune cells. J Exp Med 2021; 218:212086. [PMID: 33970190 PMCID: PMC8111463 DOI: 10.1084/jem.20202733] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/04/2021] [Accepted: 04/02/2021] [Indexed: 01/04/2023] Open
Abstract
DNMT3A encodes an enzyme that carries out de novo DNA methylation, which is essential for the acquisition of cellular identity and specialized functions during cellular differentiation. DNMT3A is the most frequently mutated gene in age-related clonal hematopoiesis. As such, mature immune cells harboring DNMT3A mutations can be readily detected in elderly persons. Most DNMT3A mutations associated with clonal hematopoiesis are heterozygous and predicted to cause loss of function, indicating that haploinsufficiency is the predominant pathogenic mechanism. Yet, the impact of DNMT3A haploinsufficiency on the function of mature immune cells is poorly understood. Here, we demonstrate that DNMT3A haploinsufficiency impairs the gain of DNA methylation at decommissioned enhancers, while simultaneously and unexpectedly impairing DNA demethylation of newly activated enhancers in mature human myeloid cells. The DNA methylation defects alter the activity of affected enhancers, leading to abnormal gene expression and impaired immune response. These findings provide insights into the mechanism of immune dysfunction associated with clonal hematopoiesis and acquired DNMT3A mutations.
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Affiliation(s)
- Jung-Yeon Lim
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Sascha H Duttke
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Turner S Baker
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Jihye Lee
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Kristyne J Gambino
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Nicholas J Venturini
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Jessica Sook Yuin Ho
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Simin Zheng
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Yesai S Fstkchyan
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Vinodh Pillai
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA
| | | | - Ivan Marazzi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Christopher Benner
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Minji Byun
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
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53
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Pfeifer GP. DNA repair in neurons and its possible link to the epigenetic machinery at enhancers. Epigenomics 2021; 13:913-917. [PMID: 33942660 DOI: 10.2217/epi-2021-0129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Gerd P Pfeifer
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI 49503, USA
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54
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Mahajan VS, Mattoo H, Sun N, Viswanadham V, Yuen GJ, Allard-Chamard H, Ahmad M, Murphy SJH, Cariappa A, Tuncay Y, Pillai S. B1a and B2 cells are characterized by distinct CpG modification states at DNMT3A-maintained enhancers. Nat Commun 2021; 12:2208. [PMID: 33850140 PMCID: PMC8044213 DOI: 10.1038/s41467-021-22458-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 03/07/2021] [Indexed: 01/29/2023] Open
Abstract
The B1 and B2 lineages of B cells contribute to protection from pathogens in distinct ways. The role of the DNA CpG methylome in specifying these two B-cell fates is still unclear. Here we profile the CpG modifications and transcriptomes of peritoneal B1a and follicular B2 cells, as well as their respective proB cell precursors in the fetal liver and adult bone marrow from wild-type and CD19-Cre Dnmt3a floxed mice lacking DNMT3A in the B lineage. We show that an underlying foundational CpG methylome is stably established during B lineage commitment and is overlaid with a DNMT3A-maintained dynamic methylome that is sculpted in distinct ways in B1a and B2 cells. This dynamic DNMT3A-maintained methylome is composed of novel enhancers that are closely linked to lineage-specific genes. While DNMT3A maintains the methylation state of these enhancers in both B1a and B2 cells, the dynamic methylome undergoes a prominent programmed demethylation event during B1a but not B2 cell development. We propose that the methylation pattern of DNMT3A-maintained enhancers is determined by the coincident recruitment of DNMT3A and TET enzymes, which regulate the developmental expression of B1a and B2 lineage-specific genes.
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Affiliation(s)
- Vinay S Mahajan
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
- Brigham and Women's Hospital, Boston, MA, USA
| | - Hamid Mattoo
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
- Immunology and Inflammation Therapeutic Area, Sanofi, Cambridge, MA, USA
| | - Na Sun
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
- Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, USA
| | - Vinayak Viswanadham
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Grace J Yuen
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
| | | | - Maimuna Ahmad
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
| | | | | | - Yesim Tuncay
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
| | - Shiv Pillai
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA.
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55
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Petryk N, Bultmann S, Bartke T, Defossez PA. Staying true to yourself: mechanisms of DNA methylation maintenance in mammals. Nucleic Acids Res 2021; 49:3020-3032. [PMID: 33300031 PMCID: PMC8034647 DOI: 10.1093/nar/gkaa1154] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/06/2020] [Accepted: 11/11/2020] [Indexed: 12/16/2022] Open
Abstract
DNA methylation is essential to development and cellular physiology in mammals. Faulty DNA methylation is frequently observed in human diseases like cancer and neurological disorders. Molecularly, this epigenetic mark is linked to other chromatin modifications and it regulates key genomic processes, including transcription and splicing. Each round of DNA replication generates two hemi-methylated copies of the genome. These must be converted back to symmetrically methylated DNA before the next S-phase, or the mark will fade away; therefore the maintenance of DNA methylation is essential. Mechanistically, the maintenance of this epigenetic modification takes place during and after DNA replication, and occurs within the very dynamic context of chromatin re-assembly. Here, we review recent discoveries and unresolved questions regarding the mechanisms, dynamics and fidelity of DNA methylation maintenance in mammals. We also discuss how it could be regulated in normal development and misregulated in disease.
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Affiliation(s)
- Nataliya Petryk
- Epigenetics and Cell Fate Centre, UMR7216 CNRS, Université de Paris, F-75013 Paris, France
| | - Sebastian Bultmann
- Department of Biology II, Human Biology and BioImaging, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Till Bartke
- Institute of Functional Epigenetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
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56
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Sun J, Yang J, Miao X, Loh HH, Pei D, Zheng H. Proteins in DNA methylation and their role in neural stem cell proliferation and differentiation. CELL REGENERATION (LONDON, ENGLAND) 2021; 10:7. [PMID: 33649938 PMCID: PMC7921253 DOI: 10.1186/s13619-020-00070-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 11/25/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND Epigenetic modifications, namely non-coding RNAs, DNA methylation, and histone modifications such as methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation play a significant role in brain development. DNA methyltransferases, methyl-CpG binding proteins, and ten-eleven translocation proteins facilitate the maintenance, interpretation, and removal of DNA methylation, respectively. Different forms of methylation, including 5-methylcytosine, 5-hydroxymethylcytosine, and other oxidized forms, have been detected by recently developed sequencing technologies. Emerging evidence suggests that the diversity of DNA methylation patterns in the brain plays a key role in fine-tuning and coordinating gene expression in the development, plasticity, and disorders of the mammalian central nervous system. Neural stem cells (NSCs), originating from the neuroepithelium, generate neurons and glial cells in the central nervous system and contribute to brain plasticity in the adult mammalian brain. MAIN BODY Here, we summarized recent research in proteins responsible for the establishment, maintenance, interpretation, and removal of DNA methylation and those involved in the regulation of the proliferation and differentiation of NSCs. In addition, we discussed the interactions of chemicals with epigenetic pathways to regulate NSCs as well as the connections between proteins involved in DNA methylation and human diseases. CONCLUSION Understanding the interplay between DNA methylation and NSCs in a broad biological context can facilitate the related studies and reduce potential misunderstanding.
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Affiliation(s)
- Jiaqi Sun
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China.
| | - Junzheng Yang
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China
| | - Xiaoli Miao
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China
| | - Horace H Loh
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China
| | - Duanqing Pei
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China.,CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou, 510530, China.,Institutes for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.,School of Life Science, Westlake University, Hangzhou, 310024, China
| | - Hui Zheng
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China. .,CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. .,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou, 510530, China. .,Institutes for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
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57
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FoxA-dependent demethylation of DNA initiates epigenetic memory of cellular identity. Dev Cell 2021; 56:602-612.e4. [PMID: 33636105 DOI: 10.1016/j.devcel.2021.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/03/2020] [Accepted: 02/02/2021] [Indexed: 12/12/2022]
Abstract
Tissue-specific DNA methylation patterns are created by transcription factors that recruit methylation and demethylation enzymes to cis-regulatory elements. To date, it is not known whether transcription factors are needed to continuously maintain methylation profiles in development and mature tissues or whether they only establish these marks during organ development. We queried the role of the pioneer factor FoxA in generating hypomethylated DNA at liver enhancers. We discovered a set of FoxA-binding sites that undergo regional, FoxA-dependent demethylation during organ development. Conditional ablation of FoxA genes in the adult liver demonstrated that continued FoxA presence was not required to maintain the hypomethylated state, even when massive cell proliferation was induced. This study provides strong evidence for the stable, epigenetic nature of tissue-specific DNA methylation patterns directed by lineage-determining transcription factors during organ development.
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58
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Ming X, Zhu B, Li Y. Mitotic inheritance of DNA methylation: more than just copy and paste. J Genet Genomics 2021; 48:1-13. [PMID: 33771455 DOI: 10.1016/j.jgg.2021.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/13/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
Decades of investigation on DNA methylation have led to deeper insights into its metabolic mechanisms and biological functions. This understanding was fueled by the recent development of genome editing tools and our improved capacity for analyzing the global DNA methylome in mammalian cells. This review focuses on the maintenance of DNA methylation patterns during mitotic cell division. We discuss the latest discoveries of the mechanisms for the inheritance of DNA methylation as a stable epigenetic memory. We also highlight recent evidence showing the rapid turnover of DNA methylation as a dynamic gene regulatory mechanism. A body of work has shown that altered DNA methylomes are common features in aging and disease. We discuss the potential links between methylation maintenance mechanisms and disease-associated methylation changes.
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Affiliation(s)
- Xuan Ming
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Bing Zhu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yingfeng Li
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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59
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Garcia-Outeiral V, de la Parte C, Fidalgo M, Guallar D. The Complexity of TET2 Functions in Pluripotency and Development. Front Cell Dev Biol 2021; 8:630754. [PMID: 33537318 PMCID: PMC7848104 DOI: 10.3389/fcell.2020.630754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 12/22/2020] [Indexed: 12/14/2022] Open
Abstract
Ten-eleven translocation-2 (TET2) is a crucial driver of cell fate outcomes in a myriad of biological processes, including embryonic development and tissue homeostasis. TET2 catalyzes the demethylation of 5-methylcytosine on DNA, affecting transcriptional regulation. New exciting research has provided evidence for TET2 catalytic activity in post-transcriptional regulation through RNA hydroxymethylation. Here we review the current understanding of TET2 functions on both DNA and RNA, and the influence of these chemical modifications in normal development and pluripotency contexts, highlighting TET2 versatility in influencing genome regulation and cellular phenotypes.
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Affiliation(s)
- Vera Garcia-Outeiral
- Stem Cells and Human Diseases Group, Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Cristina de la Parte
- Epitranscriptomics and Ageing Group, Department of Biochemistry and Molecular Biology, Center for Research in Molecular Medicine and Chronic Diseases, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Miguel Fidalgo
- Stem Cells and Human Diseases Group, Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Diana Guallar
- Epitranscriptomics and Ageing Group, Department of Biochemistry and Molecular Biology, Center for Research in Molecular Medicine and Chronic Diseases, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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60
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Tsiouplis NJ, Bailey DW, Chiou LF, Wissink FJ, Tsagaratou A. TET-Mediated Epigenetic Regulation in Immune Cell Development and Disease. Front Cell Dev Biol 2021; 8:623948. [PMID: 33520997 PMCID: PMC7843795 DOI: 10.3389/fcell.2020.623948] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/21/2020] [Indexed: 12/19/2022] Open
Abstract
TET proteins oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) and further oxidation products in DNA. The oxidized methylcytosines (oxi-mCs) facilitate DNA demethylation and are also novel epigenetic marks. TET loss-of-function is strongly associated with cancer; TET2 loss-of-function mutations are frequently observed in hematological malignancies that are resistant to conventional therapies. Importantly, TET proteins govern cell fate decisions during development of various cell types by activating a cell-specific gene expression program. In this review, we seek to provide a conceptual framework of the mechanisms that fine tune TET activity. Then, we specifically focus on the multifaceted roles of TET proteins in regulating gene expression in immune cell development, function, and disease.
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Affiliation(s)
- Nikolas James Tsiouplis
- University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill, NC, United States
| | - David Wesley Bailey
- University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill, NC, United States.,University of North Carolina Center of Translational Immunology, Chapel Hill, NC, United States.,University of North Carolina Institute of Inflammatory Disease, Chapel Hill, NC, United States
| | - Lilly Felicia Chiou
- University of North Carolina Curriculum in Genetics and Molecular Biology, Chapel Hill, NC, United States
| | - Fiona Jane Wissink
- University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill, NC, United States
| | - Ageliki Tsagaratou
- University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill, NC, United States.,University of North Carolina Center of Translational Immunology, Chapel Hill, NC, United States.,University of North Carolina Institute of Inflammatory Disease, Chapel Hill, NC, United States.,University of North Carolina Curriculum in Genetics and Molecular Biology, Chapel Hill, NC, United States.,University of North Carolina Department of Genetics, Chapel Hill, NC, United States.,University of North Carolina Department of Microbiology and Immunology, Chapel Hill, NC, United States
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61
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Takamura N, Seo H, Ohta K. TET3 dioxygenase modulates gene conversion at the avian immunoglobulin variable region via demethylation of non-CpG sites in pseudogene templates. Genes Cells 2021; 26:121-135. [PMID: 33421268 PMCID: PMC7986818 DOI: 10.1111/gtc.12828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 12/20/2022]
Abstract
Diversification of the avian primary immunoglobulin (Ig) repertoire is achieved in developing B cells by somatic hypermutation (SHM) and gene conversion (GCV). GCV is a type of homologous recombination that unidirectionally transfers segments of Ig pseudogenes to Ig variable domains. It is regulated by epigenetic mechanisms like histone modifications, but the role of DNA methylation remains unclear. Here, we demonstrate that the chicken B‐cell line DT40 lacking TET3, a member of the TET (Ten‐eleven translocation) family dioxygenases that facilitate DNA demethylation, exhibited a marked reduction in GCV activity in Ig variable regions. This was accompanied by a drop in the bulk levels of 5‐hydroxymethylcytosine, an oxidized derivative of 5‐methylcytosine, whereas TET1‐deficient or TET2‐deficient DT40 strains did not exhibit such effects. Deletion of TET3 caused little effects on the expression of proteins required for SHM and GCV, but induced hypermethylation in some Ig pseudogene templates. Notably, the enhanced methylation occurred preferably on non‐CpG cytosines. Disruption of both TET1 and TET3 significantly inhibited the expression of activation‐induced cytidine deaminase (AID), an essential player in Ig diversification. These results uncover unique roles of TET proteins in avian Ig diversification, highlighting the potential importance of TET3 in maintaining hypomethylation In Ig pseudogenes.
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Affiliation(s)
- Natsuki Takamura
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Japan
| | - Hidetaka Seo
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Japan
| | - Kunihiro Ohta
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Japan.,Universal Biology Institute, The University of Tokyo, Bunkyo-ku, Japan
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62
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TET1 Interacts Directly with NANOG via Independent Domains Containing Hydrophobic and Aromatic Residues. J Mol Biol 2020; 432:6075-6091. [PMID: 33058869 PMCID: PMC7763487 DOI: 10.1016/j.jmb.2020.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/27/2020] [Accepted: 10/07/2020] [Indexed: 11/29/2022]
Abstract
TET1 and NANOG interact via multiple independent binding regions. TET1 and NANOG interactions are mediated by aromatic and hydrophobic residues. TET1 residues that bind NANOG are highly conserved in mammals. Co-localisation of TET1 and NANOG on chromatin is enriched at NANOG target genes. NANOG and TET1 have regulatory roles in maintaining and reprogramming pluripotency.
The DNA demethylase TET1 is highly expressed in embryonic stem cells and is important both for lineage commitment, and reprogramming to naïve pluripotency. TET1 interacts with the pluripotency transcription factor NANOG which may contribute to its biological activity in pluripotent cells. However, how TET1 interacts with other proteins is largely unknown. Here, we characterise the physical interaction between TET1 and NANOG using embryonic stem cells and bacterial expression systems. TET1 and NANOG interact through multiple binding sites that act independently. Critically, mutating conserved hydrophobic and aromatic residues within TET1 and NANOG abolishes the interaction. On chromatin, NANOG is predominantly localised at ESC enhancers. While TET1 binds to CpG dinucleotides in promoters using its CXXC domain, TET1 also binds to enhancers, though the mechanism involved is unknown. Comparative ChIP-seq analysis identifies genomic loci bound by both TET1 and NANOG, that correspond predominantly to pluripotency enhancers. Importantly, around half of NANOG transcriptional target genes are associated with TET1-NANOG co-bound sites. These results indicate a mechanism by which TET1 protein may be targeted to specific sites of action at enhancers by direct interaction with a transcription factor.
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63
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Epigenetic Regulation of Dental Pulp Stem Cell Fate. Stem Cells Int 2020; 2020:8876265. [PMID: 33149742 PMCID: PMC7603635 DOI: 10.1155/2020/8876265] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 02/05/2023] Open
Abstract
Epigenetic regulation, mainly involving DNA methylation, histone modification, and noncoding RNAs, affects gene expression without modifying the primary DNA sequence and modulates cell fate. Mesenchymal stem cells derived from dental pulp, also called dental pulp stem cells (DPSCs), exhibit multipotent differentiation capacity and can promote various biological processes, including odontogenesis, osteogenesis, angiogenesis, myogenesis, and chondrogenesis. Over the past decades, increased attention has been attracted by the use of DPSCs in the field of regenerative medicine. According to a series of studies, epigenetic regulation is essential for DPSCs to differentiate into specialized cells. In this review, we summarize the mechanisms involved in the epigenetic regulation of the fate of DPSCs.
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64
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Rodrigues CP, Shvedunova M, Akhtar A. Epigenetic Regulators as the Gatekeepers of Hematopoiesis. Trends Genet 2020; 37:S0168-9525(20)30251-1. [PMID: 34756331 DOI: 10.1016/j.tig.2020.09.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 02/06/2023]
Abstract
Hematopoiesis is the process by which both fetal and adult organisms derive the full repertoire of blood cells from a single multipotent progenitor cell type, the hematopoietic stem cells (HSCs). Correct enactment of this process relies on a synergistic interplay between genetically encoded differentiation programs and a host of cell-intrinsic and cell-extrinsic factors. These include the influence of the HSC niche microenvironment, action of specific transcription factors, and alterations in intracellular metabolic state. The consolidation of these inputs with the genetically encoded program into a coherent differentiation program for each lineage is thought to rely on epigenetic modifiers. Recent work has delineated the precise contributions of different classes of epigenetic modifiers to HSC self-renewal as well as lineage specification and differentiation into various cell types. Here, we bring together what is currently known about chromatin status and the development of cells in the hematopoietic system under normal and abnormal conditions.
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Affiliation(s)
- Cecilia Pessoa Rodrigues
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; University of Freiburg, Faculty of Biology, Schaenzlestrasse 1, 79104 Freiburg, Germany; International Max Planck Research School for Molecular and Cellular Biology (IMPRS-MCB), Freiburg, Germany
| | - Maria Shvedunova
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Asifa Akhtar
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany.
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65
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Abstract
DNA methylation is a key layer of epigenetic regulation. The deposition of methylation marks relies on the catalytic activity of DNA methyltransferases (DNMTs), and their active removal relies on the activity of ten-eleven translocation (TET) enzymes. Paradoxically, in important biological contexts these antagonistic factors are co-expressed and target overlapping genomic regions. The ensuing cyclic biochemistry of cytosine modifications gives rise to a continuous, out-of-thermal equilibrium transition through different methylation states. But what is the purpose of this intriguing turnover of DNA methylation? Recent evidence demonstrates that methylation turnover is enriched at gene distal regulatory elements, including enhancers, and can give rise to large-scale oscillatory dynamics. We discuss this phenomenon and propose that DNA methylation turnover might facilitate key lineage decisions.
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66
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Li T, Ortiz-Fernández L, Andrés-León E, Ciudad L, Javierre BM, López-Isac E, Guillén-Del-Castillo A, Simeón-Aznar CP, Ballestar E, Martin J. Epigenomics and transcriptomics of systemic sclerosis CD4+ T cells reveal long-range dysregulation of key inflammatory pathways mediated by disease-associated susceptibility loci. Genome Med 2020; 12:81. [PMID: 32977850 PMCID: PMC7519528 DOI: 10.1186/s13073-020-00779-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 09/08/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Systemic sclerosis (SSc) is a genetically complex autoimmune disease mediated by the interplay between genetic and epigenetic factors in a multitude of immune cells, with CD4+ T lymphocytes as one of the principle drivers of pathogenesis. METHODS DNA samples exacted from CD4+ T cells of 48 SSc patients and 16 healthy controls were hybridized on MethylationEPIC BeadChip array. In parallel, gene expression was interrogated by hybridizing total RNA on Clariom™ S array. Downstream bioinformatics analyses were performed to identify correlating differentially methylated CpG positions (DMPs) and differentially expressed genes (DEGs), which were then confirmed utilizing previously published promoter capture Hi-C (PCHi-C) data. RESULTS We identified 9112 and 3929 DMPs and DEGs, respectively. These DMPs and DEGs are enriched in functional categories related to inflammation and T cell biology. Furthermore, correlation analysis identified 17,500 possible DMP-DEG interaction pairs within a window of 5 Mb, and utilizing PCHi-C data, we observed that 212 CD4+ T cell-specific pairs of DMP-DEG also formed part of three-dimensional promoter-enhancer networks, potentially involving CTCF. Finally, combining PCHi-C data with SSc GWAS data, we identified four important SSc-associated susceptibility loci, TNIP1 (rs3792783), GSDMB (rs9303277), IL12RB1 (rs2305743), and CSK (rs1378942), that could potentially interact with DMP-DEG pairs cg17239269-ANXA6, cg19458020-CCR7, cg10808810-JUND, and cg11062629-ULK3, respectively. CONCLUSION Our study unveils a potential link between genetic, epigenetic, and transcriptional deregulation in CD4+ T cells of SSc patients, providing a novel integrated view of molecular components driving SSc pathogenesis.
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Affiliation(s)
- Tianlu Li
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916, Badalona, Barcelona, Spain
| | - Lourdes Ortiz-Fernández
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), Granada, Spain
| | - Eduardo Andrés-León
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), Granada, Spain
| | - Laura Ciudad
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916, Badalona, Barcelona, Spain
| | - Biola M Javierre
- 3D Chromatin Organization, Josep Carreras Research Institute (IJC), 08916, Badalona, Barcelona, Spain
| | - Elena López-Isac
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), Granada, Spain
| | - Alfredo Guillén-Del-Castillo
- Unit of Systemic Autoimmunity Diseases, Department of Internal Medicine, Vall d'Hebron Hospital, Barcelona, Spain
| | - Carmen Pilar Simeón-Aznar
- Unit of Systemic Autoimmunity Diseases, Department of Internal Medicine, Vall d'Hebron Hospital, Barcelona, Spain
| | - Esteban Ballestar
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916, Badalona, Barcelona, Spain.
| | - Javier Martin
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), Granada, Spain.
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Williams BP, Gehring M. Principles of Epigenetic Homeostasis Shared Between Flowering Plants and Mammals. Trends Genet 2020; 36:751-763. [PMID: 32711945 DOI: 10.1016/j.tig.2020.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/30/2020] [Accepted: 06/30/2020] [Indexed: 12/18/2022]
Abstract
In diverse eukaryotes, epigenetic information such as DNA methylation is stably propagated over many cell divisions and generations, and can remain the same over thousands or millions of years. However, this stability is the product of dynamic processes that add and remove DNA methylation by specialized enzymatic pathways. The activities of these dynamic pathways must therefore be finely orchestrated in order to ensure that the DNA methylation landscape is maintained with high fidelity - a concept we term epigenetic homeostasis. In this review, we summarize recent insights into epigenetic homeostasis mechanisms in flowering plants and mammals, highlighting analogous mechanisms that have independently evolved to achieve the same goal of stabilizing the epigenetic landscape.
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Affiliation(s)
- Ben P Williams
- Whitehead Institute for Biomedical Research, 455 Main St, Cambridge, MA 02142, USA.
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, 455 Main St, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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