Similar Datasets
Project description:Although hematopoietic stem and progenitor cells (HSPCs) become activated in the cell-cycle status after chemotherapy to supply hematopoietic loss, the detailed mechanisms of activation remain unknown. Here we show that Sca1+ macrophages play a key role for bone marrow (BM) recovery through granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. By analyzing gene expression profiles of HSPCs lodged in 5-fluolouracil (5-FU)-treated mice, we found GM-CSF as a key proliferative signal. Sca1+ macrophages in BM after 5-FU treatment expressed high levels of GM-CSF. GM-CSF-knockout mice treated with 5-FU were lethal because of severe BM suppression. Up-regulation of Csf2 in Sca1+ macrophages by 5-FU was suppressed in MyD88-knockout mice, suggesting that TLR signaling via damage-associated molecular patterns caused by cell death is critical for up-regulation of Csf2. In 5-FU treated BM, majority of Sca1+ macrophages and transplanted HSPCs locate perivascular areas. These findings together indicate that Sca1+ macrophages induce HSPCs to proliferate through GM-CSF signaling in the stressed BM environments.
2021-01-20 | GSE120112 | GEO
Project description:Although hematopoietic stem and progenitor cells (HSPCs) become activated in the cell-cycle status after chemotherapy to supply hematopoietic loss, the detailed mechanisms of activation remain unknown. Here we show that Sca1+ macrophages play a key role for bone marrow (BM) recovery through granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. By analyzing gene expression profiles of HSPCs lodged in 5-fluolouracil (5-FU)-treated mice, we found GM-CSF as a key proliferative signal. Sca1+ macrophages in BM after 5-FU treatment expressed high levels of GM-CSF. GM-CSF-knockout mice treated with 5-FU were lethal because of severe BM suppression. Up-regulation of Csf2 in Sca1+ macrophages by 5-FU was suppressed in MyD88-knockout mice, suggesting that TLR signaling via damage-associated molecular patterns caused by cell death is critical for up-regulation of Csf2. In 5-FU treated BM, majority of Sca1+ macrophages and transplanted HSPCs locate perivascular areas. These findings together indicate that Sca1+ macrophages induce HSPCs to proliferate through GM-CSF signaling in the stressed BM environments.
2021-01-20 | GSE120111 | GEO
Project description:Sca1+ macrophages activate hematopoietic stem/progenitor cells upon bone marrow stress.
| PRJNA492805 | ENA
Project description:Sca1+ macrophages activate hematopoietic stem/progenitor cells upon bone marrow stress. [RNA-Seq]
| PRJNA492808 | ENA
Project description:Sca1+ macrophages activate hematopoietic stem/progenitor cells upon bone marrow stress. [scRNA-Seq]
| PRJNA492809 | ENA
Project description:The interaction between stem cells and their supportive microenvironment is critical for their maintenance, function, and survival. Whereas hematopoietic stem cells (HSCs) are among the best characterized of tissue stem cells, their precise site of residence (referred to as the niche) in the adult bone marrow has not been precisely defined. In this study, we found that a Gata2 promoter directs activity in all HSCs. We show that HSCs can be isolated efficiently from bone marrow cells by following Gata2-directed GFP fluorescence, and that they can also be monitored in vivo. Each individual GFP-positive cell lay in a G0/G1 cell cycle state, in intimate contact with osteoblasts beside the endosteum, at the edge of the bone marrow. We conclude that the HSC niche is composed of solitary cells and that adult bone marrow HSC are not clustered.
| S-EPMC1413708 | biostudies-literature
Project description:A resident population of dendritic cells (DCs) has been identified in murine bone marrow, but its contribution to the regulation of hematopoiesis and establishment of the stem cell niche is largely unknown. Here, we show that murine bone marrow DCs are perivascular and have a type 2 conventional DC (cDC2) immunophenotype. RNA expression analysis of sorted bone marrow DCs shows that expression of many chemokines and chemokine receptors is distinct from that observed in splenic cDC2s, suggesting that bone marrow DCs may represent a unique DC population. A similar population of DCs is present in human bone marrow. Ablation of conventional DCs (cDCs) results in hematopoietic stem/progenitor cell (HSPC) mobilization that is greater than that seen with ablation of bone marrow macrophages, and cDC ablation also synergizes with G-CSF to mobilize HSPCs. Ablation of cDCs is associated with an expansion of bone marrow endothelial cells and increased vascular permeability. CXCR2 expression in sinusoidal endothelial cells and the expression of two CXCR2 ligands, CXCL1 and CXCL2, in the bone marrow are markedly increased following cDC ablation. Treatment of endothelial cells in vitro with CXCL1 induces increased vascular permeability and HSPC transmigration. Finally, we show that HSPC mobilization after cDC ablation is attenuated in mice lacking CXCR2 expression. Collectively, these data suggest that bone marrow DCs play an important role in regulating HSPC trafficking, in part, through regulation of sinusoidal CXCR2 signaling and vascular permeability.
| S-EPMC6597218 | biostudies-literature
Project description:Hematopoietic stem/progenitor cells (HSPCs) are susceptible to benzene-induced genotoxicity. However, little is known about the mechanism of DNA damage response affecting lineage-committed progenitors for myeloid, erythroid, and lymphoid. Here, we investigated the genotoxicity of a benzene metabolite, 1,4-benzoquinone (1,4-BQ), in HSPCs using oxidative stress and lineage-directed approaches. Mouse bone marrow cells (BMCs) were exposed to 1,4-BQ (1.25-12 ?M) for 24 h, followed by oxidative stress and genotoxicity assessments. Then, the genotoxicity of 1,4-BQ in lineage-committed progenitors was evaluated using colony forming cell assay following 7-14 days of culture. 1,4-BQ exposure causes significant decreases (p < 0.05) in glutathione level and superoxide dismutase activity, along with significant increases (p < 0.05) in levels of malondialdehyde and protein carbonyls. 1,4-BQ exposure induces DNA damage in BMCs by significantly (p < 0.05) increased percentages of DNA in tail at 7 and 12 ?M and tail moment at 12 ?M. We found crucial differences in genotoxic susceptibility based on percentages of DNA in tail between lineage-committed progenitors. Myeloid and pre-B lymphoid progenitors appeared to acquire significant DNA damage as compared with the control starting from a low concentration of 1,4-BQ exposure (2.5 µM). In contrast, the erythroid progenitor showed significant damage as compared with the control starting at 5 µM 1,4-BQ. Meanwhile, a significant (p < 0.05) increase in tail moment was only notable at 7 µM and 12 µM 1,4-BQ exposure for all progenitors. Benzene could mediate hematological disorders by promoting bone marrow oxidative stress and lineage-specific genotoxicity targeting HSPCs.
| S-EPMC7459782 | biostudies-literature
Project description:The first step that precedes hematopoietic transplantation is elimination of pathological hematopoiesis by administration of myeloablative doses of radiochemotherapy. This eliminates hematolymphopoietic cells and at the same time damages hematopoietic microenvironment in bone marrow (BM). The damage of BM tissue leads to activation of complement cascade (CC), and bioactive CC cleavage fragments modulate several steps of BM recovery after transplantation of hematopoietic stem progenitor cells (HSPCs). Accordingly, C3 cleavage fragments (soluble C3a/desArgC3a and solid phase iC3b) and generation of soluble form of C5b-C9 also known as membrane attack complex (MAC) as well as release of antimicrobial cationic peptides from stromal cells (cathelicidin or LL-37 and beta-2 defensin) promote homing of HSPCs. To support this, C3 cleavage fragments and antimicrobial cationic peptides increase homing responsiveness of transplanted HSPCs to stroma-derived factor-1 (SDF-1) gradient. Furthermore, damaged BM cells release several other chemoattractants for HSPCs such as bioactive lipids sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) and chemotactic purines (ATP and UTP). In this chapter, we will discuss the current view on homing of transplanted HSPCs into BM that in addition to SDF-1 is orchestrated by CC, antimicrobial cationic peptides, and several other prohoming factors. We also propose modulation of CC as a novel strategy to optimize/accelerate homing of HSPCs.
| S-EPMC5563259 | biostudies-literature
Project description:Lineage (CD3e, CD11b, GR1, B220 and Ly-76) negative hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) infiltrate islet allografts within 24?h posttransplantation. In fact, lineage(negative) Sca-1(+) cKit(+) ("LSK") cells, a classic signature for HSCs, were also detected among these graft infiltrating cells. Lineage negative graft infiltrating cells are functionally multi-potential as determined by a standard competitive bone marrow transplant (BMT) assay. By 3 months post-BMT, both CD45.1 congenic, lineage negative HSCs/HPCs and classic "LSK" HSCs purified from islet allograft infiltrating cells, differentiate and repopulate multiple mature blood cell phenotypes in peripheral blood, lymph nodes, spleen, bone marrow and thymus of CD45.2 hosts. Interestingly, "LSK" HSCs also rapidly infiltrate syngeneic islet transplants as well as allogeneic cardiac transplants and sham surgery sites. It seems likely that an inflammatory response, not an adaptive immune response to allo-antigen, is responsible for the rapid infiltration of islet and cardiac transplants by biologically active HSCs/HPCs. The pattern of hematopoietic differentiation obtained from graft infiltrating HSCs/HPCs, cells that are recovered from inflammatory sites, as noted in the competitive BMT assay, is not precisely the same as that of intramedullary HSCs. This does not refute the obvious multi-lineage potential of graft infiltrating HSCs/HPCs.
| S-EPMC4507420 | biostudies-literature