Project description:Within the bone marrow, hematopoietic stem cells differentiate and give rise to diverse blood cell types and functions. Currently, hematopoietic progenitors are defined using surface markers combined with functional assays that are not directly linked with the in vivo potential or gene regulatory mechanisms. Here we comprehensively identify myeloid progenitor subpopulations by transcriptional sorting of single cells from the bone marrow. We describe multiple progenitor subgroups showing unexpected transcriptional priming towards seven differentiation fates, but no progenitors with a mixed state. Transcriptional differentiation is correlated with combinations of known and previously undefined transcription factors, suggesting the process is tightly regulated. Histone maps and knockout assays are consistent with the transcriptional states while traditional transplantation experiments are only partially overlapping myeloid transcriptional priming. Our analyses uncover the function of the underlying regulatory mechanisms for several sub groups and establishes a general framework for dissecting hematopoiesis. Bone marrow common myeloid progenitor H3K4me2 profiles were generated by deep sequencing of iChIP libraries on an Illumina NextSeq
Project description:Compared gene expression between Lin-Sca1-cKit+ myeloid progenitors isolated from the bone marrow of 6-8 week old wildtype and Mirc11-/- mice. Previously observed that overexpression of Mirc11 in hematopoietic progenitors increased myeloid differentiation whereas loss of Mirc11 decreased myeloid differentiation. Performed RNA-seq to identify potential genes involved in myeloid differentiation regulated by Mirc11. Gene expression analysis of Mirc11 deficient myeloid progenitors revealed a decrease in Toll like receptor and interferon signaling. This anti-inflammatory phenotype was further observed in mature cells as Mirc11-/- bone marrow derived macrophages (BMDMs) have an attenuated response to inflammatory lip-opolysaccharide (LPS).
Project description:We provide a comprehensive single cell mRNA-seq analyses of mouse bone marrow progenitors revealing early lineage commitment in the bone marrow.
Project description:This study was designed to define erythropoietin (EPO) regulated genes in murine bone marrow erythroid progenitor cells at two stages of development, designated E1, and E2. E1 cells correspond to CFUe- like progenitors, while E2 cells are proerythroblasts.
Project description:SCL/TAL1, a tissue-specific transcription factor of the basic helix-loop-helix (bHLH) family, and c-Kit, a tyrosine kinase receptor, control hematopoietic stem cell survival and quiescence. Here we report that SCL and c-Kit signaling control a common gene expression signature, of which 19 genes are associated with apoptosis. In vivo, SCL levels are limiting for the clonal expansion of Kit+ multipotent and erythroid progenitors. In addition, increased SCL expression specifically enhances the sensitivity of multipotent and megakaryocyte/erythroid progenitors to Steel factor (KIT ligand), whilst a DNA binding mutant antagonizes KIT function and induces apoptosis in progenitors. We conclude that Scl operates downstream of Kit to support the survival of megakaryocyte/erythroid progenitors. Finally, higher SCL expression upregulates Kit in normal bone marrow cells and increases chimerism after bone marrow transplantation, indicating that Scl is also upstream of Kit. We conclude that Scl and Kit establish a positive feedback loop in multipotent and megakaryocyte/erythroid progenitors. c-Kit regulated genes were extrapolated from gene expression profiles of TF-1 erythroid progenitor cells (empty MSCV vector) stimulated with SF (Kit ligand), Epo or GM-CSF. Second, SCL-regulated genes were obtained by expressing a DNA binding-defective SCL mutant (DbSCL) and selecting genes that were differentially expressed in M-oM-^AM-^DbSCL cells versus control cells (MSCV) stimulated with the same cytokines.
Project description:Mesenchymal stem/stromal cells (MSCs) function as skeletal progenitors in bone marrow and regulate hematopoiesis and hemodynamic processes via secretion of paracrine acting factors. Although TWIST1 plays important roles in mesoderm formation and skull and vascular development, its role in MSCs is poorly defined. Therefore, we conducted ChIP-seq analysis to identify genes potentially regulated by TWIST1.