Project description:We describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major mye
Project description:The leptomeninges envelop the central nervous system and contribute to brain homeostasis by producing trophic factors and regulating entrance of cells, factors and agents, immune responses and cerebrospinal fluid production. We report that leptomeninges from adult mice are regionally patterned. Leptomeninges dissected from anterior or posterior aspects of the forebrain grown in hetero- or homo-typic culture with anterior and posterior cortical cells demonstrate differences in ability to support survival of neuronal subsets and proliferation of progenitors for astrocytes and oligodendrocytes. Meningeal support changes with age: co-culture with 18-month old leptomeninges reduced numbers of cortical progenitor cells and neurons but increased astrocyte expansion. Analysis of cytokine secretion and single cell RNA-sequencing revealed differences in anterior versus posterior, young versus old meningeal factors and composition. These data demonstrate that adult leptomeninges are regionally patterned in cell composition and functional properties, and suggest that meningeal deficits may contribute to brain aging and disease.
Project description:6-plex TMT LC-MSMS quantification of proteins in myeloid progenitors (Lineage- Sca1- Kit+ cells) isolated from the bone marrow of 8-12 week old male and female control and Elp3-deficient (Elp3fl/fl vav-iCreT/+) mice. Biological triplicates of each genotype were analyzed, each consisting of 1.10e6 cells from pools of 12-14 control (Elp3fl/fl) or 26-38 (Elp3-deficient) male and female mice.
Project description:Ly6Clo monocytes are a myeloid subset that specializes in the surveillance of vascular endothelium. Ly6Clo monocytes have been shown to derive from Ly6Chi monocytes. Notch2 signaling has been implicated as a trigger for Ly6Clo monocyte development, but the basis for this effect is unclear. Here, we examined the impact of Notch2 signaling of myeloid progenitors on the development of Ly6Clo monocytes in vitro. Notch2 signaling induced by delta-like ligand 1 (DLL1) efficiently induced the transition of Ly6Chi TremL4– monocytes into Ly6Clo TremL4+ monocytes. We further discovered two additional transcriptional requirements for development of Ly6Clo monocytes. Deletion of Bcl6 from myeloid progenitors abrogated development of Ly6Clo monocyte development. IRF2 was also required for Ly6Clo monocyte development in a cell-intrinsic manner. DLL1-induced in vitro transition into Ly6Clo TremL4+ monocytes required IRF2 but unexpectedly could occur in the absence of Nur77 or Bcl6. These results imply a transcriptional hierarchy for these factors in controlling Ly6Clo monocyte development. This experiment compare RNA expression profiles between nonclassical monocytes and various cell types involved in their development.
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:The TLR9-/- mice had more myeloid cells and progenitors and fewer B cells in the bone marrow. Activity of Fos and Cebpb, important mediator of myelopoiesis, in the cluster of HSPCs were increased. PU.1 and Fos, critical transcription factors mediating osteoclastogenesis, were upregulated in monocyte progenitors. In addition to myeloid biased hematopoiesis in TLR9-/- mice, there were upregulated levels of inflammatory cytokines in the TLR9-/- bone marrow.
Project description:To investigate the role of FoxO transcription factors as mediators of hematopoietic stem cell resistance to oxidative stress. Experiment Overall Design: Study the effect of the deficiency of FoxO1, FoxO3, and FoxO4 in murine bone marrow hematopoietic stem cells and myeloid progenitors on expression of genes involved in reactive oxygen species (ROS) metabolism.