Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA149539 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:To guarantee blood supply throughout adult life hematopoietic stem cells (HSCs) need to carefully balance between self-renewing cell divisions and quiescence. Identification of genes controlling HSC self-renewal is of utmost importance given that HSCs are the only stem cells with broad clinical applications. Transcription factor PU.1 is one of the major regulators of myeloid and lymphoid development. Recent reports suggest that PU.1 mediates its functions via gradual expression level changes rather than binary on/off states. So far, this has not been considered in any study of HSCs and thus, PU.1’s role in HSC function has remained largely unclear. Here we demonstrate using hypomorphic mice with an engineered disruption of an autoregulatory feedback loop that decreased PU.1 levels resulted in loss of key HSC functions, all of which could be fully rescued by restoration of proper PU.1 levels via a human PU.1 transgene. Mechanistically, we found excessive HSC cell divisions and altered expression of cell cycle regulators whose promoter regions were bound by PU.1 in normal HSCs. Adequate PU.1 levels were maintained by a mechanism of direct autoregulation restricted to HSCs through a physical interaction of a -14kb enhancer with the proximal promoter. Our findings identify PU.1 as novel regulator controling the switch between cell division and quiescence in order to prevent exhaustion of HSCs. Given that even moderate level changes greatly impact stem cell function, our data suggest important therapeutic implications for leukemic patients with reduced PU.1 levels. Moreover, we provide first proof, that autoregulation of a transcription factor, PU.1, has a crucial function in vivo. We anticipate that our concept of how autoregulation forms an active chromosomal conformation will impact future research on transcription factor networks regulating stem cell fate. 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.
2011-12-01 | E-GEOD-33031 | biostudies-arrayexpress
Project description:To guarantee blood supply throughout adult life hematopoietic stem cells (HSCs) need to carefully balance between self-renewing cell divisions and quiescence. Identification of genes controlling HSC self-renewal is of utmost importance given that HSCs are the only stem cells with broad clinical applications. Transcription factor PU.1 is one of the major regulators of myeloid and lymphoid development. Recent reports suggest that PU.1 mediates its functions via gradual expression level changes rather than binary on/off states. So far, this has not been considered in any study of HSCs and thus, PU.1’s role in HSC function has remained largely unclear. Here we demonstrate using hypomorphic mice with an engineered disruption of an autoregulatory feedback loop that decreased PU.1 levels resulted in loss of key HSC functions, all of which could be fully rescued by restoration of proper PU.1 levels via a human PU.1 transgene. Mechanistically, we found excessive HSC cell divisions and altered expression of cell cycle regulators whose promoter regions were bound by PU.1 in normal HSCs. Adequate PU.1 levels were maintained by a mechanism of direct autoregulation restricted to HSCs through a physical interaction of a -14kb enhancer with the proximal promoter. Our findings identify PU.1 as novel regulator controling the switch between cell division and quiescence in order to prevent exhaustion of HSCs. Given that even moderate level changes greatly impact stem cell function, our data suggest important therapeutic implications for leukemic patients with reduced PU.1 levels. Moreover, we provide first proof, that autoregulation of a transcription factor, PU.1, has a crucial function in vivo. We anticipate that our concept of how autoregulation forms an active chromosomal conformation will impact future research on transcription factor networks regulating stem cell fate.
2011-12-01 | GSE33031 | 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:The transcription factor PU.1 occupies a central role in controlling myeloid and early B cell development and its correct lineage-specific expression is critical for the differentiation choice of hematopoietic progenitors. However, little is known of how this tissue-specific pattern is established. We previously identified an upstream regulatory cis-element (URE) whose targeted deletion in mice decreases PU.1 expression and causes leukemia. We show here that the URE alone is insufficient to confer physiological PU.1 expression, but requires the cooperation with other, previously unidentified elements. Using a combination of transgenic studies, global chromatin assays and detailed molecular analyses we present evidence that Pu.1 is regulated by a novel mechanism involving cross-talk between different cis-elements together with lineage-restricted autoregulation. In this model, PU.1 regulates its expression in B cells and macrophages by differentially associating with cell-type specific transcription factors at one of its cis-regulatory elements to establish differential activity patterns at other elements. Two DNaseI hypersensitivity datasets; bone marrow derived-macrophages and Splenic CD19+IgM+ B cells were used to study PU.1 regulatory elements
2011-02-21 | E-GEOD-26550 | biostudies-arrayexpress
Project description:The H3K9me3-specific histone methyltransferase SETDB1 is critical for proper regulation of developmental processes, but the underlying mechanisms are only partially understood. Here, we show that deletion of Setdb1 in mouse fetal liver hematopoietic stem and progenitor cells (HSPCs) results in compromised stem cell function, enhanced myeloerythroid differentiation, and impaired lymphoid development. Notably, Setdb1-deficient HSPCs exhibit reduced quiescence and increased proliferation, accompanied by the acquisition of a lineage-biased transcriptional program. In Setdb1-deficient HSPCs, we identify genomic regions that are characterized by loss of H3K9me3 and increased chromatin accessibility, suggesting enhanced transcription factor (TF) activity. Interestingly, hematopoietic TFs like PU.1 bind these cryptic enhancers in wild-type HSPCs, despite the H3K9me3 status. Thus, our data indicate that SETDB1 restricts activation of nonphysiological TF binding sites which helps to ensure proper maintenance and differentiation of fetal liver HSPCs.
2024-12-02 | GSE266392 | GEO
Project description:The H3K9me3-specific histone methyltransferase SETDB1 is critical for proper regulation of developmental processes, but the underlying mechanisms are only partially understood. Here, we show that deletion of Setdb1 in mouse fetal liver hematopoietic stem and progenitor cells (HSPCs) results in compromised stem cell function, enhanced myeloerythroid differentiation, and impaired lymphoid development. Notably, Setdb1-deficient HSPCs exhibit reduced quiescence and increased proliferation, accompanied by the acquisition of a lineage-biased transcriptional program. In Setdb1-deficient HSPCs, we identify genomic regions that are characterized by loss of H3K9me3 and increased chromatin accessibility, suggesting enhanced transcription factor (TF) activity. Interestingly, hematopoietic TFs like PU.1 bind these cryptic enhancers in wild-type HSPCs, despite the H3K9me3 status. Thus, our data indicate that SETDB1 restricts activation of nonphysiological TF binding sites which helps to ensure proper maintenance and differentiation of fetal liver HSPCs.
2024-12-02 | GSE266387 | GEO
Project description:The H3K9me3-specific histone methyltransferase SETDB1 is critical for proper regulation of developmental processes, but the underlying mechanisms are only partially understood. Here, we show that deletion of Setdb1 in mouse fetal liver hematopoietic stem and progenitor cells (HSPCs) results in compromised stem cell function, enhanced myeloerythroid differentiation, and impaired lymphoid development. Notably, Setdb1-deficient HSPCs exhibit reduced quiescence and increased proliferation, accompanied by the acquisition of a lineage-biased transcriptional program. In Setdb1-deficient HSPCs, we identify genomic regions that are characterized by loss of H3K9me3 and increased chromatin accessibility, suggesting enhanced transcription factor (TF) activity. Interestingly, hematopoietic TFs like PU.1 bind these cryptic enhancers in wild-type HSPCs, despite the H3K9me3 status. Thus, our data indicate that SETDB1 restricts activation of nonphysiological TF binding sites which helps to ensure proper maintenance and differentiation of fetal liver HSPCs.
2024-12-02 | GSE266388 | GEO
Project description:The transcription factor PU.1 occupies a central role in controlling myeloid and early B cell development and its correct lineage-specific expression is critical for the differentiation choice of hematopoietic progenitors. However, little is known of how this tissue-specific pattern is established. We previously identified an upstream regulatory cis-element (URE) whose targeted deletion in mice decreases PU.1 expression and causes leukemia. We show here that the URE alone is insufficient to confer physiological PU.1 expression, but requires the cooperation with other, previously unidentified elements. Using a combination of transgenic studies, global chromatin assays and detailed molecular analyses we present evidence that Pu.1 is regulated by a novel mechanism involving cross-talk between different cis-elements together with lineage-restricted autoregulation. In this model, PU.1 regulates its expression in B cells and macrophages by differentially associating with cell-type specific transcription factors at one of its cis-regulatory elements to establish differential activity patterns at other elements.
2011-02-21 | GSE26550 | GEO
Project description:Human bone marrow stromal cells (BMSCs) are key elements of the hematopoietic environment and they play a central role in bone and bone marrow physiology. However, how key BMSC functions are regulated is largely unknown. We analyzed the role of the immediate early response transcription factor EGR1 as key BMSC regulator and found that EGR1 was highly expressed in prospectively-isolated primary BMSCs, downregulated upon culture, and lower in non-CFU-F-containing CD45neg BM cells. Furthermore, EGR1 expression was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state BMSCs. Accordingly, EGR1 overexpression markedly decreased BMSC proliferation but considerably improved hematopoietic stroma support function as indicated by an increased production of transplantable CD34+CD90+ hematopoietic stem cells in expansion co-cultures. The improvement of BMSC stroma support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. On the other hand, EGR1 knockdown increased ROS-mediated BMSC proliferation, and clearly reduced BMSC hematopoietic stroma support potential. These findings thus show that EGR1 is a key BMSC transcription factor with a dual role in regulating proliferation and hematopoietic stroma support function that is controlling a genetic program to coordinate the specific functions of BMSC in their different biological contexts.
2019-06-27 | PXD011767 | Pride
Project description:PU.1 is a prototype master transcription factor (TF) of hematopoietic cell differentiation with diverse roles in different lineages. Analysis of its genome-wide binding pattern across PU.1 expressing cell types revealed manifold cell type-specific binding patterns. They are not consistent with the epigenetic and chromatin constraints to PU.1 binding observed in vitro, suggesting that PU.1 requires auxiliary factors to access DNA in vivo. Using a model of transient mRNA expression we show that PU.1 induction leads to the extensive remodeling of chromatin, redistribution of partner transcription factors and rapid initiation of a myeloid gene expression program in heterologous cell types. By probing PU.1 mutants for defects in chromatin access and screening for PU.1 proximal proteins in vivo, we found that its N-terminal acidic domain was required for the recruitment of SWI/SNF remodeling complexes, de novo chromatin access and stable binding as well as the redistribution of partner TFs.
2019-11-20 | PXD013167 | Pride