Activation of lineage competence in hemogenic endothelium precedes the formation of hematopoietic stem cell heterogeneity [Zebrafish.Cut&Tag]
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ABSTRACT: Using a combination of single-cell multi-omics, lineage tracing and functional assays, we show that embryonic HSPCs are originated from heterogeneous hemogenic endothelial cells (HECs) during zebrafish embryogenesis.
Project description:Using a combination of single-cell multi-omics, lineage tracing and functional assays, we show that embryonic HSPCs are originated from heterogeneous hemogenic endothelial cells (HECs) during zebrafish embryogenesis.
Project description:Using a combination of single-cell multi-omics, lineage tracing and functional assays, we show that embryonic HSPCs are originated from heterogeneous hemogenic endothelial cells (HECs) during zebrafish embryogenesis.
Project description:Using a combination of single-cell multi-omics, lineage tracing and functional assays, we show that embryonic HSPCs are originated from heterogeneous hemogenic endothelial cells (HECs) during zebrafish embryogenesis.
Project description:Using a combination of single-cell multi-omics, lineage tracing and functional assays, we show that embryonic HSPCs are originated from heterogeneous hemogenic endothelial cells (HECs) during zebrafish embryogenesis.
Project description:CD49f has been used to define human hematopoietic stem cells (HSCs). Tracing the origin of CD49f+ HSCs shall enhance our understanding of the regulatory mechanisms and improve in vitro generation of HSCs. Here, we employed the hematopoietic differentiation system from human pluripotent stem cells and performed a computational trajectory analysis of the cells throughout this process based on integrated calculating the levels of 10 HSC markers. We observed two clades of cell populations in the trajectory tree, one of which represents the phenotypic CD49fHigh HSCs, and the other diverges only by low CD49f level. Live cell imaging revealed that CD49f expression is persistent during endothelial-to-hematopoietic transition, suggesting that the phenotypic CD49fHigh HSCs are pre-defined in hemogenic endothelial cells (HECs), while the concurrently emerged CD49fLow cells represent HSC-independent progenitors. Colony forming assays showed that the CD49fHigh cells have multilineage potential, whereas the CD49fLow cells lack lymphoid potential but show a strong erythroid preference. The aim of the experiment was to compare newly defined CD49fHigh and CD49fLow populations from hESCs-derived HSPCs and Hemogenic Endothelium.
Project description:By tracing the VE-cadherin expression in the newborn bone marrow hematopoietic LSK (lineage minus/Sca-positive/Kit-positive) cells, we demonstrated that the late foetal/newborn BM hemogenic endothelial cells produce a small cohort of hematopoietic stem and progenitor cells (HSPCs) capable of circulating and colonizing the secondary haematopoietic organs. Phenotypic and functional analyses disclosed that BM endothelium-derived HSPCs are mainly Multipotent Progenitors (MPPs) and a few Hematopoietic Stem Cells. We used microarrays to detail the global programme of gene expression underlying the endothelial origin of LSK cells in the newborn bone marrow.
Project description:We profile the transcriptional landscape of mouse fetal placenta and identify four distinct types of haematopoietic stem/progenitor cells (HSPCs) during mid-gestation using single-cell RNA sequencing. We experimentally validate and uncover that a subpopulation of placental endothelial cells exhibits hemogenic endothelial (HE) potential and shares transcriptional features with HE cells in the aorta-gonad-mesonephros (AGM) region.
Project description:Using loss-of- and restoration-of-function approaches, we found that GATA2 function is mainly focused on enthothelial-to-hematopoietic transition (EHT) other than formation of hemogenic endothelial cells (HECs) in hematopoietic development of human ESCs. In addition, our study found that small portion of hematopoietic progenitors (HPs) can be generated even in the absence of GATA, which was proved to have similar character to that of GATA2-independent HPs lacking CFU-G and CFU-GM potential but retaining lymphoid potential.
Project description:During embryonic development, blood cells emerge from a subset of specialized endothelial cells, named hemogenic endothelial cells (HECs), via a process known as endothelial-to-hematopoietic transition (EHT). A thorough characterization of HECs and their EHT is essential to guide the efforts to derive this population from human pluripotent stem cells (hPSCs), a critical step to generate therapeutic blood products in vitro. However, current known markers used to isolate HECs are insufficient as they also enrich for arterial endothelial cells that are associated with HECs. To identify specific human HEC markers, we performed transcriptomic analysis of 28-32-day human embryos, a developmental stage characterized by active EHT. We observed that the expression of FCGR2B, encoding for the Fc receptor CD32 previously associated with other specialized endothelia, is highly enriched in the ACE+CD34+ endothelial cell population that contains HECs. Functional ex vivo analyses confirmed that multilineage hematopoietic potential is highly enriched in CD32+ endothelial cells isolated from the aorta-gonad-mesonephros region and yolk sac of human embryos. In addition, CD32 emerged as selective marker for hPSC-derived HECs across different hematopoietic programs. Remarkably, our analyses showed that CD32 expression identifies HECs that are irreversibly bound to undergo EHT. As such, CD32 expression enriches for cells with hemogenic potential with a higher specificity for hPSC-derived HECs than other known HEC markers. These findings provide a simple method for isolating HECs from human embryos and hPSC cultures, allowing the efficient generation of hematopoietic cells in vitro.
Project description:During embryonic development, blood cells emerge from a subset of specialized endothelial cells, named hemogenic endothelial cells (HECs), via a process known as endothelial-to-hematopoietic transition (EHT). A thorough characterization of HECs and their EHT is essential to guide the efforts to derive this population from human pluripotent stem cells (hPSCs), a critical step to generate therapeutic blood products in vitro. However, current known markers used to isolate HECs are insufficient as they also enrich for arterial endothelial cells that are associated with HECs. To identify specific human HEC markers, we performed transcriptomic analysis of 28-32-day human embryos, a developmental stage characterized by active EHT. We observed that the expression of FCGR2B, encoding for the Fc receptor CD32 previously associated with other specialized endothelia, is highly enriched in the ACE+CD34+ endothelial cell population that contains HECs. Functional ex vivo analyses confirmed that multilineage hematopoietic potential is highly enriched in CD32+ endothelial cells isolated from the aorta-gonad-mesonephros region and yolk sac of human embryos. In addition, CD32 emerged as selective marker for hPSC-derived HECs across different hematopoietic programs. Remarkably, our analyses showed that CD32 expression identifies HECs that are irreversibly bound to undergo EHT. As such, CD32 expression enriches for cells with hemogenic potential with a higher specificity for hPSC-derived HECs than other known HEC markers. These findings provide a simple method for isolating HECs from human embryos and hPSC cultures, allowing the efficient generation of hematopoietic cells in vitro.