Project description:To gain insight into regulation of B cell development by C/EBPa, we compared gene expression in hCD4- vs hCD4+ subsets of preproB and proB cells from Cebpa-Enh/prom-hCD4 mice, with preB cells and hCD4+ GMP also analyzed for comparison.
Project description:The key myeloid transcription factor (TF) CEBPA is frequently mutated in acute myeloid leukemia (AML), but the molecular ramifications of this leukemic driver mutation remain elusive. To investigate CEBPA mutant AML, we compared gene expression changes in human CEBPA mutant AML and in the corresponding CebpaLp30 mouse model, and identified a conserved cross-species transcriptional program. ChIP-seq revealed aberrantly activated enhancers, exclusively occupied by the leukemia-associated CEBPA-p30 isoform. One leukemic-enhancer upstream of Nt5e, encoding CD73, was physically and functionally linked to this conserved AML gene, and could be activated by CEBPA. Targeting of CD73-adenosine signaling increased AML survival in transplanted mice. Our data indicate a first-in-class link between a TF cancer driver mutation and a druggable, direct transcriptional target.
Project description:Knockouts of the Cebpa gene or its +37kb enhancer in mice show two major findings: (1) neutropenia in bone marrow and blood; (2) decrease in long-term hematopoietic stem cell (LT-HSC) numbers. To study mechanisms linking the two observed events, we applied RNA sequencing on +37kbWT and +37kbHOM bone marrow cells. The analysis of these data revealed that myeloid priming in HSPCs occurs before Cebpa activation and that a neutrophil differentiation block in these progenitors potentially leads to HSC quiescence exit.
Project description:Analysis of global RNA expression of Cebpa knockdown lineage-negative marrow cells reveals known and potentially novel C/EBPa targets. Total RNA from lineage-negative marrow progenitors transduced with vector or Cebpa shRNA and cultured under myeloid differentiation condition for 2 days were compared.
Project description:Analysis of global RNA expression of Cebpa knockdown lineage-negative marrow cells reveals known and potentially novel C/EBPa targets.
Project description:C/EBPalpha is a transcription factor critically involved in myeloid development and indispensable for formation of granulocytes. To track the cellular fate of stem and progenitor (LSK) cells, which express C/EBPalpha, we developed a mouse model expressing Cre recombinase from the Cebpa promoter and an inducible EYFP allele. We show that Cebpa/EYFP+ cells represent a significant subset of LSK cells, which predominantly give rise to myeloid cells in steady state hematopoiesis. C/EBPalpha induced a robust myeloid gene expression signature and downregulated E2A-induced regulators of early lymphoid development. In addition, Cebpa/EYFP+ cells comprise a fraction of early thymic progenitors (ETP) with robust myeloid potential. However, Cebpa/EYFP+ LSK and ETP cells retained the ability to develop into erythroid and T-lymphoid lineages, respectively. These findings support an instructive, but argue against a lineage restrictive role of C/EBPalpha in multipotent hematopoietic and thymic progenitors. We performed global gene expression profiling of double-sorted Cebpa/EYFP+ and Cebpa/EYFP- LSK cells of pooled Cebpa Cre/wt R26 EYFP reporter mice to identify differentially regulated genes in Cebpa+ versus Cebpa- LSK cells. RNA was isolated from three biological replicates of Cebpa/EYFP+ LSK cells and two biological replicates of Cebpa/EYFP- LSK cells. To determine if the identified genes were truly dependent on Cebpa expression, we also performed global gene expression profilling of Cebpa/EYFP+ and Cebpa/EYFP- fetal liver LSK cells of Cebpa Cre/fl R26 EYFP mice. Induction of Cebpa/Cre expression in these mice leads to Cre-mediated recombination of the floxed wt Cebpa allele resulting in a complete Cebpa knock-out. In this case, RNA was isolated from two biological replicates of either Cebpa/EYFP+ and Cebpa/EYFP- LSK cells. In addition, we included one biological replicate of Cebpa/EYFP+ and Cebpa/EYFP- fetal liver LSK cells of Cebpa Cre/wt R26 EYFP mice to determine the correlation of differentially regulated genes in bone marrow and fetal liver LSK cells.
Project description:The study uncovers epigenomic changes associated with dexamethasone response heterogeneity in myeloma cells, revealing rewired promoter-enhancer interactions and DNA loop stabilization
Project description:Enhancers harbor instructions encoded for the interactions between cis-elements and transcription factors to orchestrate lineage specific gene programs. Here we developed a modified method for chromosome conformation capture (3C), named MID Hi-C, to reveal how in mouse embryonic stem cells differential cooperation of enhancers and the chromatin remodeler BAF, as instructed by the underlying transcription factor motifs, modulate enhancer-promoter communication. We show that BAF-dependent enhancers permit genomic interactions beyond enhancer boundaries. BAF-dependent enhancers do not dictate genomic interactions within enhancer-promoter loop domains but rather act to instruct remote enhancer-promoter communication. In contrast, BAF-independent enhancers interact with promoter regions within tightly insulated enhancer-promoter loop domains that are marked by promoter and enhancer boundary elements. In addition, enhancer activeness modulated by BAF enforces compartment segregation. Based on these observations, we propose that enhancer cis elements instruct with great precision BAF-induced enhancer-promoter communication and compartmental segregation.
Project description:To gain insight into regulation of B cell development by C/EBPa, we compared gene expression in preproB cells with or without the +37 kb Cebpa enhancer.