This SuperSeries is composed of the SubSeries listed below.
Polycomb repressive complex 2 is required for MLL-AF9 leukemia.
Specimen part, Disease, Disease stage
View SamplesWe evaluated gene expression changes in murine leukemia caused by retroviral overexpression of MLL-AF9. We compared wild-type (WT) leukemia cells with mutant leukemia cells after cre-mediated inactivation of homozygous conditional alleles for Ezh2 or Eed, both of which are components of the Polycomb Repressive Complex2.
Polycomb repressive complex 2 is required for MLL-AF9 leukemia.
Specimen part, Disease, Disease stage
View SamplesWe evaluated gene expression changes in secondary recipient murine leukemia caused by retroviral overexpression of MLL-AF9. We compared wild-type (WT) leukemia cells with mutant leukemia cells after cre-mediated inactivation of a homozygous conditional allele for Ezh2, a component of the Polycomb Repressive Complex2.
Polycomb repressive complex 2 is required for MLL-AF9 leukemia.
Specimen part, Disease, Disease stage
View SamplesTo identify a cohort of rhythmically expressed genes in the murine Distal Colon,microarrays were used to measure gene expression over a 24-hour light/dark cycle.The rhythmic transcripts were classified according to expression patterns, functions and association with physiological and pathophysiological processes of the colon including motility, colorectal cancer formation and inflammatory bowel disease.
Transcriptional profiling of mRNA expression in the mouse distal colon.
No sample metadata fields
View SamplesMLL-fusions may induce leukemogenic gene expression programs by recruiting the histone H3K79 methyltransferase to MLL-target promoters. We evaluated gene expression changes after cre-mediated loss of Dot1l in leukemia cells obtained from mice injected with MLL-9 transformed lineage negative bone marrow cells.
MLL-rearranged leukemia is dependent on aberrant H3K79 methylation by DOT1L.
Specimen part
View SamplesWe investigated the role of mTORC1 in murine hematopoiesis by conditionally deleting the Raptor gene in murine hematopoietic stem cells. We observed mutliple alterations evoked by Raptor loss in hematopoiesis and profiled gene-expression alterations induced by raptor loss in Flt3-Lin-Sca1+cKit+ hematopoietic stem and progenitor enriched cell populations, 5 weeks post Raptor deletion.
mTOR complex 1 plays critical roles in hematopoiesis and Pten-loss-evoked leukemogenesis.
Specimen part
View SamplesFetal and adult -globin gene expression is tightly regulated during human development. Fetal globin genes are transcriptionally silenced during embryogenesis through the process of hemoglobin switching. Efforts to understand the transcriptional mechanism(s) behind fetal globin silencing have led to novel strategies to derepress fetal globin expression in the adult, which could alleviate symptoms in hereditary b-globin disorders including sickle cell disease (SCD) and -thalassemia. We identified a novel zinc finger protein, pogo transposable element with zinc finger domain (Pogz), expressed in mouse and human hematopoietic stem and progenitor cells, which represses embryonic b-like globin gene expression in mice. Ablation of Pogz expression in adult hematopoietic cells in vivo results in persistence of embryonic b-like globin expression without significantly affecting erythroid development or mouse survival. Elevated embryonic -like globin expression correlates with reduced expression of Bcl11a, a known repressor of embryonic -like globin expression, in Pogz-/- fetal liver cells. Pogz binds to the Bcl11a promoter, and, to erythroid specific intragenic regulatory regions. Importantly, Pogz+/- mice develop normally, but show elevated embryonic b-like globin expression in peripheral blood cells, demonstrating that reducing Pogz levels results in persistence of embryonic b-like globin expression. Finally, knockdown of POGZ in primary human CD34+ hematopoietic stem and progenitor cell derived erythroblasts, reduces BCL11A expression and increases fetal hemoglobin expression. These findings are significant since new therapeutic targets and strategies are needed to treat the increasing global burden of b-globin disorders.
POGZ Is Required for Silencing Mouse Embryonic β-like Hemoglobin and Human Fetal Hemoglobin Expression.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
IRF-8 extinguishes neutrophil production and promotes dendritic cell lineage commitment in both myeloid and lymphoid mouse progenitors.
Specimen part
View SamplesWhile most blood lineages are assumed to mature through a single cellular and developmental route downstream of hematopoietic stem cells (HSCs), dendritic cells (DCs) can be derived from both myeloid and lymphoid progenitors in vivo. To determine how distinct progenitors can generate similar downstream lineages, we examined the transcriptional changes that accompany loss of in vivo myeloid potential as common myeloid progenitors (CMPs) differentiate into common dendritic cell progenitors (CDPs), and as lymphoid-primed multipotent progenitors (LMPPs) differentiate into all lymphoid progenitors (ALPs). Microarray studies revealed that Interferon regulatory factor 8 (IRF-8) expression increased during each of these transitions. Competitive reconstitutions using Irf8-/- bone marrow demonstrated cell-intrinsic defects in the formation of CDPs and all splenic dendritic cell subsets. Irf8-/- CMPs and, unexpectedly, Irf8-/- ALPs produced more neutrophils in vivo than their wild type counterparts at the expense of DCs. Retroviral expression of IRF-8 in multiple progenitors led to reduced neutrophil production and increased numbers of DCs, even in the granulocyte-macrophage progenitor (GMP), which does not normally possess conventional DC potential. These data suggest that IRF-8 represses a neutrophil module of development and promotes convergent DC development from multiple lymphoid and myeloid progenitors autonomously of cellular context.
IRF-8 extinguishes neutrophil production and promotes dendritic cell lineage commitment in both myeloid and lymphoid mouse progenitors.
Specimen part
View SamplesProductive rearrangement of the immunoglobulin heavy chain locus triggers a major developmental checkpoint that promotes limited clonal expansion of pre-B cells, culminating in cell cycle arrest and rearrangement of the kappa () or lambda () light-chain loci. B lineage cells lacking the related transcription factors IRF-4 and IRF-8 undergo a developmental arrest at the cycling pre-B cell stage and are blocked for light-chain recombination. Using Irf-4,8-/- pre-B cells we demonstrate that two pathways converge to synergistically drive light-chain rearrangement, a process that is not simply activated by cell cycle exit. One pathway is directly dependent on IRF-4, whose expression is elevated by pre-BCR signaling. IRF-4 targets the 3 and enhancers to increase locus accessibility and positions a kappa allele away from pericentromeric heterochromatin. The other pathway is triggered by attenuation of IL-7 signaling and results in activation of the intronic enhancer via binding of the transcription factor, E2A. Intriguingly, IRF-4 regulates the expression of CXCR4 and promotes the migration of pre-B cells in response to the chemokine CXCL12. We propose that IRF-4 coordinates the two pathways regulating light-chain recombination by positioning pre-B cells away from IL-7 expressing stromal cells.
Regulation of immunoglobulin light-chain recombination by the transcription factor IRF-4 and the attenuation of interleukin-7 signaling.
No sample metadata fields
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