Gene expression profile of microglia and border-associated macrophages carrying hDNMT3A mutation
Ontology highlight
ABSTRACT: To probe for the impact of a age-related clonal hematopoiesis associated somatic mutation on monocyte-derived microglia and macrophages in the CNS, we took advantage of a mouse model that harbors a replacement of the murin Dnmt3a gene with a cDNA cassette encoding the human DNMT3A R882H variant. To seed the CNS with monocyte-derived cells from hDNMT3A mut hematopoietic stem cells, we engrafted Cx3cr1-gfp mice with bone marrow of 10-month-old Vav-Cre: hDNMT3A fl/fl mice. After 4 months following irradiation, endogenous microglia and leptomeningeal macrophages, and engrafted cells were isolated from both mutation and wild type groups for bulk RNAseq analysis.
Project description:After irradiation and bone-marrow transplantation, most of microglia and boarder-associated macrophages in the central nervous system is replaced by engranft cells. Taking advantages of Ms4a3-Cre: R26-TdTomato: Cx3cr1-gfp mice, we discriminated cells from monocyte precursors and hematopoietic stem cells with colors at 32 weeks following irradiation and bone-marrow transplantation. We sorted HSC-derived, monocyte-derived, and endogenouse microglia and leptomeningeal macrophages, and analyzed gene expression level between different cell populations using a bulk RNAseq method.
Project description:Ms4a3-Cre: R26-TdTomato: Cx3cr1-gfp mice allow discrimination between YS-derivd and monocyte-derived macrophages in the brain parenchyma and leptomeninges by color. We used single cell RNAseq for RNA profiling to compare YS-derived micrglia, monocyte-derived microglia, YS-derived leptomeningeal macrophages, and monocyte-derived leptomeningeal macrophages.
Project description:Microglia are the resident macrophages of the central nervous system (CNS). Gene profiling identified the transcriptional regulator Sall1 as a microglia signature gene. Given the high expression of Sall1 in microglia, we sought to identify its function in vivo. The Sall1CreER allele has been targeted into the Sall1 locus, therefore Sall1CreER/fl mice (heterozygous for both alleles) allow inducible ablation of Sall1 expression in microglia after tamoxifen treatment. We performed RNA-seq to examine gene expression profiles of microglia sorted from tamoxifen treated adult Sall1CreER/fl mice and Sall1fl/fl control littermates. Microglia were obtained with > 98% purity and the absence of Sall1 was confirmed in Sall1CreER/fl microglia. We could show that deletion of Sall1 in microglia in vivo resulted in the conversion of these cells from resting tissue macrophages into inflammatory phagocytes leading to altered neurogenesis and disturbed tissue homeostasis. Similar changes in gene expression profiles were found in Sall1-deficient microglia isolated from tamoxifen-treated Cx3cr1CreERSall1fl/fl mice. In these mice, deletion of Sall1 is targeted to CX3CR1+ myeloid cells including microglia and CNS-associated macrophages but not to any other CNS-resident cells. This indicated that Sall1 transcriptional regulation maintains microglia identity and physiological properties in the CNS.
Project description:Gene profiling of CNS-derived microglia vs splenic CD11b+Ly6C+ monocyte subsets deom adult mice Gene array identified 1572 genes that were enriched in microglia vs. 611 monocyte enriched genes with a greater than 5-fold difference (P<0.001). Gene profiling of CD11b+CD45Low microglia isolated from the CNS and CD11b+Ly6C+ monocyte subsets isolated from the spleen of naM-CM-/ve adult mice.
Project description:DNA methyltransferase 3A (DNMT3A) is frequently mutated in hematological cancers; however, the underlying oncogenic mechanism remains elusive. Here, we report that DNMT3A mutational hotspot at Arg882 (DNMT3A R882H) cooperates with NRAS mutation to transform hematopoietic stem/progenitor cells and induce acute leukemia development. Mechanistically, DNMT3A R882H directly binds to and potentiates transactivation of stemness genes critical for leukemogenicity including Meis1, Mn1 and Hoxa gene cluster. DNMT3A R882H induces focal epigenetic alterations, including CpG hypomethylation and concurrent gain of active histone modifications, at cis-regulatory elements such as enhancers to facilitate gene transcription. CRISPR/Cas9-mediated ablation of a putative Meis1 enhancer carrying DNMT3A R882H-induced DNA hypomethylation impairs Meis1 expression. Importantly, DNMT3A R882H-induced gene expression programs can be repressed through Dot1l inhibition, providing an attractive therapeutic strategy for DNMT3A-mutated leukemias. This SuperSeries is composed of the SubSeries listed below.
Project description:DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies. We report that DNMT3A mutational ‘hotspot’ at Arg882 (i.e., DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. Mechanistically, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation. In this dataset, we provided microarray data showing effect of BRD4 inhibitor I-BET151 on gene expression in leukemic stem cells transformed by DNMT3A R882H and NRAS G12D.
Project description:Multiple Sclerosis (MS) is a neuroinflammatory disease characterized by demyelinated lesions in the CNS. Remyelination in MS is variable between individuals and tends to become less efficient with aging. Microglia and astrocytes are known to have critical roles in MS pathogenesis, but to what extent their activity is altered by remyelination failure remains unclear. To determine the effects of demyelination on neuroinflammation, we use two mouse models that genetically ablate myelinating oligodendrocytes. We use the Plp1-CreERT mouse line crossed with the Myrf fl/fl mouse line to induce genetic demyelination throughout the CNS following adult tamoxifen administration. Subsequent remyelination is mediated by the proliferation and differentiation of oligodendrocyte precursor cells (OPCs) to newly formed oligodendrocytes. To assess the consequences of remyelination failure, we deleted Myrf from both mature oligodendrocytes and OPCs using Myrf fl/fl; Sox10-CreERT mice, which both induces demyelination and impairs subsequent remyelination. To characterize the glial cells in these demyelinated mice, we performed single-nucleus RNA-sequencing (snRNAseq) of optic nerves at peak demyelination, generating an atlas of non-neuronal cells including oligodendrocyte lineage cells, astrocytes, microglia, endothelial cells, pericytes, arachnoid barrier cells, vascular and leptomeningeal cells.
Project description:DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we report that DNMT3A mutational âhotspotâ at Arg882 (DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. DNMT3A-R882H potentiates aberrant transactivation of âstemnessâ gene expression programs, notably transcription factors Meis1, Hox-A, Mn1 and Mycn. Mechanistically, R882-mutated DNMT3A directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Inactivation of Dot1l represses DNMT3AR882H-mediated stem cell gene dysregulation and acute leukemogenicity. In this dataset, we provided enhanced Reduced Representation Bisulfite Sequencing (eRRBS) DNA methylome profiling data showing effect of DNMT3A R882H mutation or WT expression on hematopoietic stem/progenitor cells with NRAS G12D co-transduction. eRRBBs DNA methylome analysis of Lin- enriched hematopoietic stem/progenitor cells with retroviral infection of NRAS G12D alone (EV-RAS), DNMT3A R882H with NRAS G12D (RH-RAS) or DNMT3A WT with NRAS G12D (WT-RAS) at day 16 post-transduction.
Project description:DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we report that DNMT3A mutational âhotspotâ at Arg882 (DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. DNMT3A-R882H potentiates aberrant transactivation of âstemnessâ gene expression programs, notably transcription factors Meis1, Hox-A, Mn1 and Mycn. Mechanistically, R882-mutated DNMT3A directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Inactivation of Dot1l represses DNMT3AR882H-mediated stem cell gene dysregulation and acute leukemogenicity. In this dataset, we provided H3K4me1, H3K27ac and H3K79me2 ChIP-seq profiling data showing effect of DNMT3A R882H mutation or WT expression on epigenetic landscapes of hematopoietic stem/progenitor cells with NRAS G12D co-transduction. ChIP-seq analysis of Lin- enriched hematopoietic stem/progenitor cells with retroviral infection of NRAS G12D alone (EV-RAS), DNMT3A R882H with NRAS G12D (RH-RAS) or DNMT3A WT with NRAS G12D (WT-RAS) 3 weeks post-transduction. Antibodies of H3K4me1, H3K27ac and H3K79me2 were used.
Project description:DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we report that DNMT3A mutational â??hotspotâ?? at Arg882 (i.e., DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. DNMT3A-R882H potentiates aberrant transactivation of â??stemnessâ?? gene expression programs, notably transcription factors Meis1, Hox-A, Mn1 and Mycn. Mechanistically, R882-mutated DNMT3A directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Inactivation of Dot1l represses DNMT3AR882H-mediated stem cell gene dysregulation and acute leukemogenicity. In this dataset, we provided microarray data showing effect of R882H-mutated or WT DNMT3A on gene expression among HSPCs with NRAS G12D co-transduction. Microarray analysis of Lin- enriched hematopoietic stem/progenitor cells with retroviral infection of NRAS G12D alone (EV-RAS), DNMT3A R882H with NRAS G12D (RH-RAS) or DNMT3A WT with NRAS G12D (WT-RAS) at day 12 or day 16 post-transduction.