Ascorbic acid enhances Tet-mediated 5-methylcytosine oxidation and promotes DNA demethylation in mammals.
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Zechen Chong
PROVIDER: E-GEOD-43262 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:DNA demethylation occurs in multiple cellular processes but its regulation is poorly understood. Here we report that a vital nutrient factor ascorbic acid (AA), or vitamin C (Vc), induces DNA demethylation in mammalian cells. The levels of active 5mC oxidation products, 5-formylcytosine and 5-carboxylcytosine, increase by more than one magnitude of order in mouse ES cells when cultured in the presence of AA. In cells deleted of Tet1 and Tet2 dioxygenase genes, AA does not facilitate 5mC oxidation. The AA effect is however restored when Tet2 was re-expressed in the mutant cells. The enhancing effect of AA on 5mC oxidation and DNA demethylation was also observed in a mouse model deficient in AA synthesis. Our results thus reveal a role of AA in the regulation of DNA modification, which might mediate a plethora of functions of AA.
2015-01-01 | GSE43262 | GEO
Project description:Ten-eleven translocation (Tet) family of DNA dioxygenases converts 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- carboxylcytosine (5caC) through iterative oxidation reactions. While 5mC and 5hmC are relatively abundant, 5fC and 5caC are at very low levels in the mammalian genome. Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place. Here, we have performed high-throughput sequencing analysis of 5mC/5hmC/5fC/5caC- enriched DNA using modification-specific antibodies and generated genome-wide distribution maps of these cytosine modifications in wild-type and Tdg-deficient mouse embryonic stem cells (ESCs). We observe that the steady state 5fC and 5caC are preferentially detected at repetitive sequences in wild-type mouse ESCs. Depletion of TDG causes marked accumulation of 5fC and 5caC at a large number of distal gene regulatory elements and transcriptionally repressed/poised gene promoters, suggesting that Tet/TDG-dependent dynamic cycling of 5mC oxidation states may be involved in regulating the function of these regions. Thus, comprehensive mapping of 5mC oxidation and BER pathway activity in the mammalian genome provides a promising approach for better understanding of biological roles of DNA methylation and demethylation dynamics in development and diseases. In this dataset, we include the DIP-seq data of 5mC, 5hmC, 5fC and 5caC in both control and Tdg knockdown mouse embryonic stem cells.
2013-04-18 | E-GEOD-46111 | biostudies-arrayexpress
Project description:TET1/2/3 are methylcytosine dioxygenases regulating cytosine hydroxymethylation in the genome. Tet1 and Tet2 are abundantly expressed in HSC/HPCs and implicated in the pathogenesis of hematological malignancies. Tet2-deletion in mice causes myeloid malignancies, while Tet1-null mice develop B-cell lymphoma after an extended period of latency. Interestingly, TET1 and TET2 were often concomitantly down-regulated in acute B-lymphocytic leukemia. Here, we investigated the overlapping and non-redundant functions of Tet1/Tet2 in HSC maintenance and development of hematological malignancies using Tet1/2 double knockout (DKO) mice. DKO and Tet2-/- HSC/HPCs had overlapping and unique 5hmC and 5mC profiles and behaved differently. DKO mice exhibited strikingly decreased incidence and delayed onset of myeloid malignancies compared to Tet2-/- mice and in contrast developed lethal B-cell malignancies. Transcriptome analysis of DKO tumors revealed expression changes in many genes dysregulated in human B-cell malignancies, such as LMO2, BCL6 and MYC. These results highlight the critical roles of TET1 or TET2 individually and their cross-talks in the pathogenesis of hematological malignancies. Given the role of Tet proteins in 5mC oxidation, we employed a previously established chemical labeling and affinity purification method coupled with high-throughput sequencing (hMe-Seal) to profile the genome-wide distribution of 5hmC, as well as methylated DNA immunoprecipitation (MeDIP) coupled with high-throughput sequencing (MeDIP-seq) to profile 5mC using BM LK cells purified from young WT, Tet2-/- and DKO mice (6-10 wks old).
2015-11-12 | E-GEOD-73611 | biostudies-arrayexpress
Project description:Ten-eleven translocation (TET) proteins oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytsosine (5fC), and 5-carboxylcytosine (5caC). 5fC/5caC can be excised and repaired by the base excision repair (BER) pathway, implicating 5mC oxidation in active DNA demethylation. Genome-wide DNA methylation is erased in the transition from metastable states to ground state of embryonic stem cells (ESCs) and in migrating primordial germ cells (PGCs), while some resistant regions become demethylated only in gonadal PGCs. Understanding the mechanisms underlying global hypomethylation in naïve ESCs and developing PGCs will be useful for realizing cellular pluripotency and totipotency. In this study, we found that PRDM14, the PR-domain-containing transcriptional regulator, accelerates the TET-BER cycle, resulting in the promotion of active DNA demethylation in ESCs. Induction of PRDM14 expression rapidly removed the 5mC associated with transient elevation of 5hmC at pluripotency-associated genes, germline-specific genes, and imprinted loci but not across the entire genome, which resemble second wave of DNA demethylation in gonadal PGCs. PRDM14 physically interacts with TET1/TET2 and enhances the recruitment of TET1/TET2 at target loci. Knockdown of Tet1/Tet2 impaired transcriptional regulation and DNA demethylation by PRDM14. The repression of the BER pathway by administration of pharmacological inhibitors against APE1 and PARP1 and the knockdown of thymine DNA glycosylase (TDG) also impaired DNA demethylation by PRDM14. Furthermore, DNA demethylation induced by PRDM14 normally takes place in the presence of aphidicolin, which is an inhibitor of G1/S progression. Together, our analysis provides mechanistic insight into DNA demethylation in naive pluripotent stem cells and developing PGCs. To investigate the function of TET1/TET2 in transcriptional regulation by PRDM14 in ESCs, we exploited microarray analysis using total mRNA derived from Scramble, Scramble + PRDM14, Tet1/Tet2 KD, Tet1/Tet2 KD + PRDM14 mouse ESC.
2013-12-31 | E-GEOD-52598 | biostudies-arrayexpress
Project description:Cytosine DNA bases can be methylated by DNA methyltransferases and subsequently oxidized by TET proteins. The resulting 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) are considered demethylation intermediates as well as stable epigenetic marks. To dissect the contribution of these cytosine modifying enzymes, we generated combinations of Tet knockout (KO) embryonic stem cells (ESCs) and systematically measured protein and DNA modification levels at the transition from naive to primed pluripotency. Whereas the increase of genomic 5-methylcytosine (5mC) levels during exit from pluripotency correlated with an upregulation of the de novo DNA methyltransferases DNMT3A and DNMT3B, the subsequent oxidation steps turned out to be far more complex. The strong increase of oxidized cytosine bases (5hmC, 5fC, and 5caC) was accompanied by a drop in TET2 levels, yet the analysis of KO cells suggested that TET2 is responsible for most 5fC formation. The comparison of modified cytosine and enzyme levels in Tet KO cells revealed distinct and differentiation-dependent contributions of TET1 and TET2 to 5hmC and 5fC formation arguing against a processive mechanism of 5mC oxidation. The apparent independent steps of 5hmC and 5fC formation suggest yet to be identified mechanisms regulating TET activity and may constitute another layer of epigenetic regulation.
2020-07-24 | PXD019514 | Pride
Project description:With the exception of imprinted genes and certain repeats, DNA methylation is globally erased during pre-implantation development. Recent studies have suggested that Tet3-mediated oxidation of 5-methylcytosine (5mC) and DNA replication-dependent dilution both contribute to global paternal DNA demethylation, but demethylation of the maternal genome occurs via replication. Here we present genome-scale DNA methylation maps for both the paternal and maternal genomes of Tet3-depleted and/or DNA replication-inhibited zygotes. In both genomes, we found that inhibition of DNA replication blocks DNA demethylation independently from Tet3 function, and that Tet3 facilitates DNA demethylation by coupling with DNA replication. For both, our data indicate that replication-dependent dilution is the major contributor to demethylation, but Tet3 plays an important role, particularly at certain loci. Our study therefore both defines the respective functions of Tet3 and DNA replication in paternal DNA demethylation and reveals an unexpected contribution of Tet3 to demethylation of the maternal genome. In this data set, we include RNA-Seq data of mouse 2-cell embryos and blastocysts derived from both wildtype and Tet3-null oocytes
2014-10-21 | E-GEOD-61329 | biostudies-arrayexpress
Project description:We proposed that besides TET family dioxygenase oxidizing 5mC to 5hmC, there is a non-enzyme pathway which is due to hydroxyl radica l(OH) or OH-like species also involvement in demethylation of 5mC forming 5hmC. This pathway includes classical fenton reagents such as H2O2 and Fe2+, and more important redox-activity quinoid compounds, especially, tetrachloro-1,4-benzoquinone (TCBQ), which was reported producing hydroxyl radicals independent of transition metal Examination of 5hmC and transcriptome levels with TCBQ and DMSO in human MRC-5 cell lines
2013-12-05 | E-GEOD-44457 | biostudies-arrayexpress
Project description:TET protein-catalyzed 5mC oxidation not only creates novel DNA modifications such as 5hmC, but also initiates active or passive DNA demethylation. However, the TETsâ function in crosstalk with specific histone modifications is largely elusive. Here, we show that TET2-mediated DNA demethylation plays a primary role in the de novo establishment and maintenance of H3K4me3/H3K27me3 bivalent domain underlying the methylated DNA CpG islands (CGIs). Overexpression of wild type (WT) but not catalytic inactive mutant (Mut) TET2 in TET-low-expressing cells results in increase of 5hmC level and accompanying DNA demethylation at a subset of CGIs. Importantly, this is sufficient to create de novo bivalent domains at these loci. Genome-wide analysis reveals that these de novo synthesized bivalent domains are largely associated with a subset of key developmental gene promoters, which are often located within CpG islands that are previously hyper-methylated and silenced. On the other hand, depletion of Tet1 and Tet2 in mouse ES cells results in an apparent loss of H3K27me3 at bivalent domains, which are located within CGIs and associated with a particular set of key developmental gene promoters. Collectively, these data suggest that TET proteins have a primary role in charge of regulating the crosstalk between two key epigenetic mechanisms, DNA methylation and histone methylation (H3K4me3 and H3K27me3), particularly at a subset of CpG islands associated with developmental genes. We examined H3K4me3,H3K27me3,5mC and 5hmC in 293T and mES cell types,using Illumina Hiseq2500.
2016-07-25 | E-GEOD-72481 | biostudies-arrayexpress
Project description:The TET proteins TET1, TET2 and TET3 constitute a new family of dioxygenases that utilize molecular oxygen and the cofactors Fe(II) and 2-oxoglutarate to convert 5-methylcytosine (5mC) to 5-hydroxy-methylcytosine (5hmC) and further oxidation products in DNA1-5. Here we show that Tet1 and Tet2 have distinct roles in regulating 5hmC deposition and gene expression in mouse embryonic stem cells (mESC). Tet1 depletion in mESC primarily diminishes 5hmC levels at transcription start sites (TSS), whereas Tet2 depletion is mostly associated with decreased 5hmC in gene bodies relative to TSS. 5hmC is enriched at exon start and end sites, especially in exons that are highly expressed, and is significantly decreased upon Tet2 knockdown at the boundaries of high-expressed exons that are selectively regulated by Tet2. In differentiating murine B cells, Tet2 deficiency is associated with selective exon exclusion in the gene encoding the transmembrane phosphatase CD45. Tet2 depletion is associated with increased 5hmC and decreased 5mC at promoters/ TSS regions, possibly because of the redundant activity of Tet1. Together, these data indicate a complex interplay between Tet1 and Tet2 in mESC, and show that loss-of-function of a single TET protein does not necessarily lead to loss of 5hmC and a corresponding gain of 5mC, as generally assumed. The relation between Tet2 loss-of-function and selective changes in exon expression could potentially explain the frequent occurrence of both TET2 loss-of-function mutations and mutations in proteins involved in pre-mRNA splicing in myeloid malignancies in humans. Gene and exon expression analysis in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by RNA-sequencing. Mapping of 5-hydroxymethylcytosine in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by anti-CMS-seq. Mapping of methylcytosine in mESC, and Tet2 kd mESC by MeDIP-seq.
2014-01-16 | E-GEOD-50200 | biostudies-arrayexpress
Project description:Ten-eleven translocation (TET) proteins oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytsosine (5fC), and 5-carboxylcytosine (5caC). 5fC/5caC can be excised and repaired by the base excision repair (BER) pathway, implicating 5mC oxidation in active DNA demethylation. Genome-wide DNA methylation is erased in the transition from metastable states to ground state of embryonic stem cells (ESCs) and in migrating primordial germ cells (PGCs), while some resistant regions become demethylated only in gonadal PGCs. Understanding the mechanisms underlying global hypomethylation in naïve ESCs and developing PGCs will be useful for realizing cellular pluripotency and totipotency. In this study, we found that PRDM14, the PR-domain-containing transcriptional regulator, accelerates the TET-BER cycle, resulting in the promotion of active DNA demethylation in ESCs. Induction of PRDM14 expression rapidly removed the 5mC associated with transient elevation of 5hmC at pluripotency-associated genes, germline-specific genes, and imprinted loci but not across the entire genome, which resemble second wave of DNA demethylation in gonadal PGCs. PRDM14 physically interacts with TET1/TET2 and enhances the recruitment of TET1/TET2 at target loci. Knockdown of Tet1/Tet2 impaired transcriptional regulation and DNA demethylation by PRDM14. The repression of the BER pathway by administration of pharmacological inhibitors against APE1 and PARP1 and the knockdown of thymine DNA glycosylase (TDG) also impaired DNA demethylation by PRDM14. Furthermore, DNA demethylation induced by PRDM14 normally takes place in the presence of aphidicolin, which is an inhibitor of G1/S progression. Together, our analysis provides mechanistic insight into DNA demethylation in naive pluripotent stem cells and developing PGCs.
2013-12-31 | GSE52598 | GEO