Mus musculus
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ABSTRACT:
PROVIDER: PRJNA171355 | ENA |
REPOSITORIES: ENA
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Project description:Tet2 is an enzyme that hydroxylates methylated cytosines and has been implicated in hematopoietic differentiation and the formation of myeloid malignancies when mutated. An ideal system to study the role of Tet2 in myelopoeisis is C/EBPa induced transdifferentiation of pre-B cells into macrophages, where many myeloid genes become rapidly upregulated. Here we found that C/EBPa binds to upstream regions of Tet2 and that the gene becomes activated. Tet2 knockdowns impaired the upregulation of macrophage markers as well as phagocytic capacity, suggesting that the enzyme is required for both early and late stages of myeloid differentiation. A slightly weaker effect was seen in primary cells with a Tet2 ablation. Expression arrays of transdifferentiating cells with Tet2 knockdowns permitted the identification of a small subset of myeloid genes whose upregulation was blunted. Activation of these target genes was accompanied by a rapid increase of promoter hydroxy-methylation. Our observations indicate that Tet2 helps C/EBPa to rapidly de-repress myeloid genes during the conversion of pre-B cells into macrophages. Gene expression was measured in a control and Tet2kd mouse preB cell line (called Haftl) harboring an inducible form of C/EBPa. Expression was measured in starting cells and cells induced to transdifferentiate into macrophage-like cells for 24 hours. Technical duplicates for each treatment and time were assayed.
2012-07-26 | E-GEOD-39666 | biostudies-arrayexpress
Project description:Tet2 is an enzyme that hydroxylates methylated cytosines and has been implicated in hematopoietic differentiation and the formation of myeloid malignancies when mutated. An ideal system to study the role of Tet2 in myelopoeisis is C/EBPa induced transdifferentiation of pre-B cells into macrophages, where many myeloid genes become rapidly upregulated. Here we found that C/EBPa binds to upstream regions of Tet2 and that the gene becomes activated. Tet2 knockdowns impaired the upregulation of macrophage markers as well as phagocytic capacity, suggesting that the enzyme is required for both early and late stages of myeloid differentiation. A slightly weaker effect was seen in primary cells with a Tet2 ablation. Expression arrays of transdifferentiating cells with Tet2 knockdowns permitted the identification of a small subset of myeloid genes whose upregulation was blunted. Activation of these target genes was accompanied by a rapid increase of promoter hydroxy-methylation. Our observations indicate that Tet2 helps C/EBPa to rapidly de-repress myeloid genes during the conversion of pre-B cells into macrophages.
2012-07-27 | GSE39666 | GEO
Project description:In blood, the transcription factor C/EBPa is essential for myeloid differentiation and has been implicated in regulating self-renewal of fetal liver hematopoietic stem cells (HSCs). However, its function in adult HSCs is unknown. Here, using an inducible knockout model, we found that C/EBPa deficient adult HSCs underwent a pronounced expansion with enhanced proliferation, characteristics resembling fetal liver HSCs. Consistently, transcription profiling of C/EBPa deficient HSCs revealed a gene expression program similar to fetal liver HSCs. Moreover we observed that age-specific C/EBPa expression correlated with its inhibitory effect on the HSC cell cycle. Mechanistically, we identified N-Myc as a C/EBPa downstream target. C/EBPa upregulation during HSC transition from an active fetal state to a quiescent adult state was accompanied by down-regulation of N-Myc, and loss of C/EBPa resulted in de-repression of NMyc. Our data establish that C/EBPa acts as a molecular switch between fetal and adult states of HSC in part via transcriptional repression of the proto-oncogene N-Myc.
2012-11-14 | GSE42234 | GEO
Project description:In blood, the transcription factor C/EBPa is essential for myeloid differentiation and has been implicated in regulating self-renewal of fetal liver hematopoietic stem cells (HSCs). However, its function in adult HSCs is unknown. Here, using an inducible knockout model, we found that C/EBPa deficient adult HSCs underwent a pronounced expansion with enhanced proliferation, characteristics resembling fetal liver HSCs. Consistently, transcription profiling of C/EBPa deficient HSCs revealed a gene expression program similar to fetal liver HSCs. Moreover we observed that age-specific C/EBPa expression correlated with its inhibitory effect on the HSC cell cycle. Mechanistically, we identified N-Myc as a C/EBPa downstream target. C/EBPa upregulation during HSC transition from an active fetal state to a quiescent adult state was accompanied by down-regulation of N-Myc, and loss of C/EBPa resulted in de-repression of NMyc. Our data establish that C/EBPa acts as a molecular switch between fetal and adult states of HSC in part via transcriptional repression of the proto-oncogene N-Myc. HSCs of Pu.1 knock-in (PU.1ki/ki) mice were used for RNA extraction and hybridization on Affymetrix microarrays. We compared these microarray samples with the corresponding wild type.
2012-11-14 | E-GEOD-42234 | biostudies-arrayexpress
Project description:Collombet2016 - Lymphoid and myeloid cell
specification and transdifferentiation
This model is described in the article:
Logical modeling of lymphoid
and myeloid cell specification and transdifferentiation
Samuel Collombet, Chris van Oevelen,
Jose Luis Sardina Ortega, Wassim Abou-Jaoudé, Bruno Di
Stefano, Morgane Thomas-Chollier, Thomas Graf, and Denis
Thieffry
Proceedings of the National Academy of
Sciences of the United States of America
Abstract:
Blood cells are derived from a common set of hematopoietic
stem cells, which differentiate into more specific progenitors
of the myeloid and lymphoid lineages, ultimately leading to
differentiated cells. This developmental process is controlled
by a complex regulatory network involving cytokines and their
receptors, transcription factors, and chromatin remodelers.
Using public data and data from our own molecular genetic
experiments (quantitative PCR, Western blot, EMSA) or
genome-wide assays (RNA-sequencing, ChIP-sequencing), we have
assembled a comprehensive regulatory network encompassing the
main transcription factors and signaling components involved in
myeloid and lymphoid development. Focusing on B-cell and
macrophage development, we defined a qualitative dynamical
model recapitulating cytokine-induced differentiation of common
progenitors, the effect of various reported gene knockdowns,
and the reprogramming of pre-B cells into macrophages induced
by the ectopic expression of specific transcription factors.
The resulting network model can be used as a template for the
integration of new hematopoietic differentiation and
transdifferentiation data to foster our understanding of
lymphoid/myeloid cell-fate decisions.
This model is hosted on
BioModels Database
and identified by:
MODEL1610240000.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
2017-06-08 | MODEL1610240000 | BioModels
Project description:C/EBPα induces transdifferentiation of B cells into macrophages at high efficiencies and enhances reprogramming into induced pluripotent stem cells (iPSCs) when co-expressed with Oct4, Sox2, Klf4 and Myc (OSKM). However, how C/EBPα accomplishes these effects is unclear. We now found that transient C/EBPα expression followed by OSKM activation induces a 100 fold increase in iPSC reprogramming efficiency, involving 95% of the cells. During this conversion pluripotency and epithelial-mesenchymal transition genes become dramatically up-regulated and 60% of the cells express Oct4 within 2 days. C/EBPα acts as a pathbreaker since it transiently makes the chromatin of pluripotency genes more accessible to DNase I. It also induces the expression of the dioxygenase Tet2 and promotes its translocation to the nucleus where it binds to regulatory regions of pluripotency genes that become demethylated following OSKM induction. In line with these findings, overexpression of Tet2 enhances OSKM‐induced B cell reprogramming. Since the enzyme is also required for efficient C/EBPα-induced immune cell conversion, our data suggest that Tet2 provides a mechanistic link between iPSC reprogramming and B cell transdifferentiation. The rapid iPS reprogramming approach described should help to fully elucidate the process and has potential clinical applications. Change in Cebpa genome binding/occupancy, comparing primary B-cells treated with estradiol for 18h to induce C/EBPa to untreated cells.
2013-11-17 | E-GEOD-52373 | biostudies-arrayexpress
Project description:C/EBP? induces transdifferentiation of B cells into macrophages at high efficiencies and enhances reprogramming into induced pluripotent stem cells (iPSCs) when co-expressed with Oct4, Sox2, Klf4 and Myc (OSKM). However, how C/EBP? accomplishes these effects is unclear. We now found that transient C/EBP? expression followed by OSKM activation induces a 100 fold increase in iPSC reprogramming efficiency, involving 95% of the cells. During this conversion pluripotency and epithelial-mesenchymal transition genes become dramatically up-regulated and 60% of the cells express Oct4 within 2 days. C/EBP? acts as a pathbreaker since it transiently makes the chromatin of pluripotency genes more accessible to DNase I. It also induces the expression of the dioxygenase Tet2 and promotes its translocation to the nucleus where it binds to regulatory regions of pluripotency genes that become demethylated following OSKM induction. In line with these findings, overexpression of Tet2 enhances OSKM?induced B cell reprogramming. Since the enzyme is also required for efficient C/EBP?-induced immune cell conversion, our data suggest that Tet2 provides a mechanistic link between iPSC reprogramming and B cell transdifferentiation. The rapid iPS reprogramming approach described should help to fully elucidate the process and has potential clinical applications. Change in gene expression, comparing primary B-cells treated with estradiol for 18h to induce C/EBPa to untreated cells.
2013-11-17 | E-GEOD-52396 | biostudies-arrayexpress
Project description:Earlier work has shown that pre-B cells can be converted into macrophages by the transcription factor C/EBP? at very high frequencies. Using this system we have now performed a systematic analysis of the question whether during transdifferentiation the cells transiently reactivate progenitor restricted genes or even retrodifferentiate. A transcriptome analysis of transdifferentiating cells showed that most genes are continuously up or downregulated, acquiring a macrophage phenotype within 5 days. In addition, we observed the transient reactivation of a subset of immature myeloid markers, as well as low levels of the progenitor markers Kit and Flt3 and a few lineage inappropriate genes. However, we were unable to observe the re-expression of cell surface marker combinations that characterize hematopoietic stem and progenitor cells (HSPCs), including c-Kit and Flt3. This was the case even when C/EBPalpha was activated in pre-B cells under culture conditions that favor HSPC growth or when the transcription factor was activated in a time limited fashion. Together, our findings are consistent with the notion that the conversion from pre-B cells to macrophages is mostly direct and does not involve overt retrodifferentiation. Our microarray data indicate that most expression changes are direct, and that transdifferentiation does not involve retrodifferentiation. Our data also show that there is a low level transient activation of selected progenitor genes, as well as myeloid precursor genes. Primary mouse pre-B cells were infected with an inducible form of C/EBPa and cells induced to transdifferentiate with beta Estradiol (b-Est) harvested at different time points to analyze expression profiles, using Affymetrix 430.2 arrays.
2011-11-30 | E-GEOD-32330 | biostudies-arrayexpress
Project description:Loss-of-function TET2 mutations (TET2MT) are common in myeloid neoplasia. TET2, a DNA dioxygenase, requires 2-oxoglutarate and Fe(II) to oxidize 5-methylcytosine. TET2MT thus result in hypermethylation and transcriptional repression. Ascorbic acid (AA) increases dioxygenase activity by facilitating Fe(III)/Fe(II) redox reaction and may alleviate some biological consequences of TET2MT by restoring dioxygenase activity. Here, we report the utility of AA in the prevention of TET2MT MN, clarify the mechanistic underpinning of the TET2-AA interactions, and demonstrate that the ability of AA to restore TET2 activity in cells depends on N- and C-terminal lysine acetylation and nature of TET2MT. Consequently, pharmacologic modulation of acetyltransferases and histone deacetylases may regulate TET dioxygenase-dependent AA effects. Thus, our study highlights the contribution of factors that may enhance or attenuate AA effects on TET2 and provides a rationale for novel therapeutic approaches including combinations of AA with class I/II HDAC inhibitor or sirtuin activators in TET2MT leukemia.
2020-09-09 | PXD020550 | Pride
Project description:TET2 is one of the most frequently mutated genes in hematological malignancies. TET2 mutations are also frequently observed in healthy individuals with clonal hematopoiesis. Additional factors, such as inflammatory stress, might promote the expansion and initiate the pre-leukemic condition of Tet2 deficient hematopoietic stem cells. Antibiotics treatment is frequently used in normal individuals and patients with hematological malignancies treatment to suppress infection-induced inflammation. However, prolonged antibiotics treatment resulted in bone marrow suppression and gut microbiota alteration. In our study, we observed that the expansion of Tet2 deficient myeloid cells are positively correlated with serum cytokine levels at pre-malignant stages. We then evaluated the effect of antibiotic treatment in Tet2 deficient myeloid and lymphoid tumors in vivo. We found that antibiotics treatment suppressed the growth of Tet2 deficient malignant cells in vivo. RNA-seq analysis revealed significant changes in immune related signaling pathways (e.g., Tnf-α signaling) in antibiotics treated Tet2 deficient myeloid and lymphoid tumor cells. Suppression of Tnf-α signaling using pharmacological inhibitors partially suppressed Tet2 deficient tumor cell growth in vivo. In summary, our results suggest that the expansion of Tet2 deficient blood cells are positively associated with a pre-inflammatory condition and suppression of inflammatory pathways may attenuate the progression of TET2 inactivation-associated hematological malignancies.
2021-04-01 | GSE129886 | GEO