Genome-wide mapping of 5-hydroxymethylcytosine enrichment in a novel model of 'NAFLD in a Dish'
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE144955 | GEO | 2020/12/03
REPOSITORIES: GEO
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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:The TET family of dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), but their involvement in establishing normal 5mC patterns during mammalian development and their contributions to aberrant control of 5mC during cellular transformation remains largely unknown. We depleted TET1, TET2, and TET3 by siRNA in a pluripotent embryonic carcinoma cell model and examined the impact on genome-wide 5mC and 5hmC patterns. TET1 depletion yielded widespread reduction of 5hmC, while depletion of TET2 and TET3 reduced 5hmC at a subset of TET1 targets suggesting functional co-dependence. TET2 or TET3-depletion also caused increased 5hmC, suggesting they play a major role in 5hmC removal. All TETs prevent hypermethylation throughout the genome, a finding dramatically illustrated in CpG island shores, where TET depletion resulted in prolific hypermethylation. Surprisingly, TETs also promote methylation, as hypomethylation was associated with 5hmC reduction. TET function was highly specific to chromatin environment: 5hmC maintenance by all TETs occurred at polycomb-marked chromatin and genes expressed at moderate levels; 5hmC removal by TET2 is associated with highly transcribed genes enriched for H3K4me3 and H3K36me3. Importantly, genes prone to hypermethylation in cancer become depleted of 5hmC with TET deficiency, suggesting the TETs normally promote 5hmC at these loci, and all three TETs are required for 5hmC enrichment at enhancers, a condition necessary for expression of adjacent genes. These results provide novel insight into the division of labor among TET proteins and reveal an important connection of TET activity with chromatin landscape and gene expression. Methylation and hydroxymethylation profiling by affinity-based high throughput sequencing
2014-06-14 | E-GEOD-51902 | biostudies-arrayexpress
Project description:The TET family of dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), but their involvement in establishing normal 5mC patterns during mammalian development and their contributions to aberrant control of 5mC during cellular transformation remains largely unknown. We depleted TET1, TET2, and TET3 by siRNA in a pluripotent embryonic carcinoma cell model and examined the impact on genome-wide 5mC and 5hmC patterns. TET1 depletion yielded widespread reduction of 5hmC, while depletion of TET2 and TET3 reduced 5hmC at a subset of TET1 targets suggesting functional co-dependence. TET2 or TET3-depletion also caused increased 5hmC, suggesting they play a major role in 5hmC removal. All TETs prevent hypermethylation throughout the genome, a finding dramatically illustrated in CpG island shores, where TET depletion resulted in prolific hypermethylation. Surprisingly, TETs also promote methylation, as hypomethylation was associated with 5hmC reduction. TET function was highly specific to chromatin environment: 5hmC maintenance by all TETs occurred at polycomb-marked chromatin and genes expressed at moderate levels; 5hmC removal by TET2 is associated with highly transcribed genes enriched for H3K4me3 and H3K36me3. Importantly, genes prone to hypermethylation in cancer become depleted of 5hmC with TET deficiency, suggesting the TETs normally promote 5hmC at these loci, and all three TETs are required for 5hmC enrichment at enhancers, a condition necessary for expression of adjacent genes. These results provide novel insight into the division of labor among TET proteins and reveal an important connection of TET activity with chromatin landscape and gene expression. Affymetrix gene expression Human ST1.0 microarray of NCCIT human embryonic carcinoma cells (4 samples in duplicate).
2014-06-14 | E-GEOD-51901 | biostudies-arrayexpress
Project description:Ten-eleven translocation (Tet) hydroxylases (Tet1-3) oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). In neurons increased 5hmC levels within gene bodies correlate positively with gene expression. The mechanisms controlling Tet activity and 5hmC levels are poorly understood. In particular, it is not known how the neuronal Tet3 isoform lacking a DNA binding domain is targeted to the DNA. To identify factors binding to Tet3 we screened for proteins that co-precipitate with Tet3 from mouse retina and identified the transcriptional repressor Rest as a highly enriched Tet3-specific interactor. Rest was able to enhance Tet3 hydroxylase activity after co-expression and overexpression of Tet3 activated transcription of Rest-target genes. Moreover, we found that Tet3 also interacts with Nsd3 and two other H3K36 methyltransferases and is able to induce H3K36 trimethylation. We propose a mechanism for transcriptional activation in neurons that involves Rest-guided targeting of Tet3 to the DNA for directed 5hmC-generation and Nsd3-mediated H3K36 trimethylation.
2015-04-02 | PXD001857 | Pride
Project description:The TET family of dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), but their involvement in establishing normal 5mC patterns during mammalian development and their contributions to aberrant control of 5mC during cellular transformation remains largely unknown. We depleted TET1, TET2, and TET3 by siRNA in a pluripotent embryonic carcinoma cell model and examined the impact on genome-wide 5mC and 5hmC patterns. TET1 depletion yielded widespread reduction of 5hmC, while depletion of TET2 and TET3 reduced 5hmC at a subset of TET1 targets suggesting functional co-dependence. TET2 or TET3-depletion also caused increased 5hmC, suggesting they play a major role in 5hmC removal. All TETs prevent hypermethylation throughout the genome, a finding dramatically illustrated in CpG island shores, where TET depletion resulted in prolific hypermethylation. Surprisingly, TETs also promote methylation, as hypomethylation was associated with 5hmC reduction. TET function was highly specific to chromatin environment: 5hmC maintenance by all TETs occurred at polycomb-marked chromatin and genes expressed at moderate levels; 5hmC removal by TET2 is associated with highly transcribed genes enriched for H3K4me3 and H3K36me3. Importantly, genes prone to hypermethylation in cancer become depleted of 5hmC with TET deficiency, suggesting the TETs normally promote 5hmC at these loci, and all three TETs are required for 5hmC enrichment at enhancers, a condition necessary for expression of adjacent genes. These results provide novel insight into the division of labor among TET proteins and reveal an important connection of TET activity with chromatin landscape and gene expression.
2014-06-14 | GSE51902 | GEO
Project description:The TET family of dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), but their involvement in establishing normal 5mC patterns during mammalian development and their contributions to aberrant control of 5mC during cellular transformation remains largely unknown. We depleted TET1, TET2, and TET3 by siRNA in a pluripotent embryonic carcinoma cell model and examined the impact on genome-wide 5mC and 5hmC patterns. TET1 depletion yielded widespread reduction of 5hmC, while depletion of TET2 and TET3 reduced 5hmC at a subset of TET1 targets suggesting functional co-dependence. TET2 or TET3-depletion also caused increased 5hmC, suggesting they play a major role in 5hmC removal. All TETs prevent hypermethylation throughout the genome, a finding dramatically illustrated in CpG island shores, where TET depletion resulted in prolific hypermethylation. Surprisingly, TETs also promote methylation, as hypomethylation was associated with 5hmC reduction. TET function was highly specific to chromatin environment: 5hmC maintenance by all TETs occurred at polycomb-marked chromatin and genes expressed at moderate levels; 5hmC removal by TET2 is associated with highly transcribed genes enriched for H3K4me3 and H3K36me3. Importantly, genes prone to hypermethylation in cancer become depleted of 5hmC with TET deficiency, suggesting the TETs normally promote 5hmC at these loci, and all three TETs are required for 5hmC enrichment at enhancers, a condition necessary for expression of adjacent genes. These results provide novel insight into the division of labor among TET proteins and reveal an important connection of TET activity with chromatin landscape and gene expression.
2014-06-14 | GSE51901 | GEO
Project description:Although clear cell renal cell carcinoma (ccRCC) has been shown to result in widespread aberrant cytosine methylation and loss of 5-hydroxymethylcytosine (5hmC), the prognostic impact and therapeutic targeting of tis epigenetic aberrancy has not been fully explored. Analysis of 576 primary ccRCC samples demonstrated that loss of 5hmC was significantly associated with aggressive clinicopathologic features and was an independent adverse prognostic factor. Loss of 5hmC alsopredicted reduced progression-free survival after resection of nonmetastatic disease. The loss of 5hmC in ccRCC was not due to mutational or transcriptional inactivation of ten eleven translocation (TET) (4. AUTHOR: TET also appears as Tet. If these mean the same thing, choose one style to use throughout.) enzymes, but to their functional inactivation by l -2-hydroxyglutarate (L2HG), which was overexpressed due to the deletion and underexpression of L2HG dehydrogenase(L2HGDH). Ascorbic acid (AA) reduced methylation and restored genome-wide 5hmC levels via TET activation. Fluorescence quenching of the recombinant TET-2 protein was unaffected by L2HG in the presence of AA. Pharmacologic AA treatment led to reduced growth of ccRCC in vitro and reduced tumor growth in vivo, with increased intratumoral 5hmC. These data demonstrate that reduced 5hmC is associated with reduced survival in ccRCC and provide a preclinical rationale for exploring the therapeutic potential of high-dose AA in ccRCC.
2019-04-03 | GSE126823 | GEO
Project description:5-hydroxymethylcytosine (5hmC) is a recently discovered epigenetic modification that is lost in human cancers. Formation of 5hmC is catalysed by the Ten eleven translocation (TET) proteins that mediate the sequential oxidation of 5-methylcytosine (5mC) to 5hmC, leading to eventual DNA demethylation. Several mechanisms can lead to loss of 5hmC in cancers, including mutations in IDH or TET2 genes. However, little is known about the role of TET proteins and 5hmC in adult cells. Here, we report that TET1 downmodulation is required to permit adult cells to proliferate. TET1 is rapidly downmodulated in proliferating primary cells and in regenerating liver. TET1 silencing accelerates cell cycle progression while its constitutive expression inhibits cell growth. TET1 is a negative regulator of cell proliferation and it is regulated during development in tissue specific manner. These findings enlarge our knowledge on how one epigenetic modification such as the DNA hydroxymethylation mediated by TET1 is a key player on the control of cell proliferation. Examination of 5hmC in MEF at passage 0 and at passage 5.
2015-08-04 | E-GEOD-57250 | biostudies-arrayexpress
Project description:5-hydroxymethylcytosine (5hmC) is a recently discovered epigenetic modification that is lost in human cancers. Formation of 5hmC is catalysed by the Ten eleven translocation (TET) proteins that mediate the sequential oxidation of 5-methylcytosine (5mC) to 5hmC, leading to eventual DNA demethylation. Several mechanisms can lead to loss of 5hmC in cancers, including mutations in IDH or TET2 genes. However, little is known about the role of TET proteins and 5hmC in adult cells. Here, we report that TET1 downmodulation is required to permit adult cells to proliferate. TET1 is rapidly downmodulated in proliferating primary cells and in regenerating liver. TET1 silencing accelerates cell cycle progression while its constitutive expression inhibits cell growth. TET1 is a negative regulator of cell proliferation and it is regulated during development in tissue specific manner. These findings enlarge our knowledge on how one epigenetic modification such as the DNA hydroxymethylation mediated by TET1 is a key player on the control of cell proliferation.
2015-08-04 | GSE57250 | GEO
Project description:TET enzymes are dioxygenases that promote DNA demethylation by oxidizing the methyl group of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). Here we report a close correspondence between 5hmC-marked regions, chromatin accessibility and enhancer activity in B cells, and a strong enrichment for consensus binding motifs for basic region-leucine zipper (bZIP) transcription factors at TET-responsive genomic regions. Functionally, Tet2 and Tet3 regulate class switch recombination (CSR) in murine B cells by enhancing expression of Aicda, encoding the cytidine deaminase AID essential for CSR. TET enzymes deposit 5hmC, demethylate and maintain chromatin accessibility at two TET-responsive elements, TetE1 and TetE2, located within a superenhancer in the Aicda locus. Transcriptional profiling identified BATF as the bZIP transcription factor involved in TET-dependent Aicda expression. 5hmC is not deposited at TetE1 in activated Batf-deficient B cells, indicating that BATF recruits TET proteins to the Aicda enhancer. Our data emphasize the importance of TET enzymes for bolstering AID expression, and highlight 5hmC as an epigenetic mark that captures enhancer dynamics during cell activation.
2019-04-29 | GSE116204 | GEO