BioProject

Human embryonic stem cells (hESCs) are a powerful tool for modeling regenerative therapy. To search for the genes that promote hematopoietic development from human pluripotent stem cell, we overexpressed a list of hematopoietic regulator genes in human pluripotent stem cell-derived CD34+CD43- endothelial cells (ECs) enriched in hemogenic endothelium. Among genes tested, only SOX17, a gene encoding a transcription factor of the SOX family, promoted cell growth and supported expansion of CD34+CD43+CD45-/low cells expressing a hemogenic endothelial maker VE-cadherin. SOX17 was highly expressed in CD34+CD43- ECs but at a low level in CD34+CD43+CD45- pre-hematopoietic progenitor cells (pre-HPCs) and CD34+CD43+CD45+ HPCs. SOX17-overexpressing cells formed sphere-like colonies and generated few hematopoietic progenies. More...

Human embryonic stem cells (hESCs) are a powerful tool for modeling regenerative therapy. To search for the genes that promote hematopoietic development from human pluripotent stem cell, we overexpressed a list of hematopoietic regulator genes in human pluripotent stem cell-derived CD34+CD43- endothelial cells (ECs) enriched in hemogenic endothelium. Among genes tested, only SOX17, a gene encoding a transcription factor of the SOX family, promoted cell growth and supported expansion of CD34+CD43+CD45-/low cells expressing a hemogenic endothelial maker VE-cadherin. SOX17 was highly expressed in CD34+CD43- ECs but at a low level in CD34+CD43+CD45- pre-hematopoietic progenitor cells (pre-HPCs) and CD34+CD43+CD45+ HPCs. SOX17-overexpressing cells formed sphere-like colonies and generated few hematopoietic progenies. However, they retained hemogenic potential and gave rise to hematopoietic progenies upon inactivation of SOX17. Global gene expression analyses revealed that the CD34+CD43+CD45-/low cells expanded upon overexpression of SOX17 are hemogenic endothelium-like cells developmentally placed between ECs and pre-HPCs. Of interest, SOX17 also reprogrammed both pre-HPCs and HPCs into hemogenic endothelium-like cells. Genome-wide mapping of SOX17 revealed that SOX17 directly activates transcription of key regulator genes for vasculogenesis, hematopoiesis, and erythrocyte differentiation. Depletion of SOX17 in CD34+CD43- ECs severely compromised their hemogenic activity. These findings suggest that SOX17 plays a critical role in priming hemogenic potential in ECs, thereby regulates hematopoietic development from hESCs. This SuperSeries is composed of the SubSeries listed below. Overall design: ChIP on chip analysis was carried out using the Mouse Promoter ChIP-on-chip Microarray Set (G4490A, Agilent, Palo Alto, Calif., USA). MEFs were subjected to ChIP assay using a Ring1B antibody. Purified immunoprecipitated and input DNA was subjected to T7 RNA polymerase-based amplification. Labeling, hybridization and washing were carried out according to the Agilent mammalian ChIP-on-chip protocol (ver.9.0). Scanned images were quantified with Agilent Feature Extraction software under standard conditions. Human ES cells were differentiated for 6 days in EBs, then CD34+CD43-CD45- endothelial cells were isolated, plated onto OP9 cells, and transduced with the 4OH-tamoxifen (4OHT)-inducible 3×FLAG-tagged Sox17-ERT retrovirus. The cells were seeded on OP9 stromal cells and cultured in the presence of 4OH-tamoxifen. At day 27 of the co-culture with OP9 cells, CD34+CD43+CD45low hemogenic endothelium-like cells overexpressing Sox17-ERT were collected by CD34 magnetic-activated cell sorting (MACS) and subjected to a ChIP-chip analysis. ChIP on chip analysis was carried out using the Mouse Promoter ChIP-on-chip Microarray Set (G4490A, Agilent, Palo Alto, Calif., USA). MEFs were subjected to ChIP assay using a Ring1B antibody. Purified immunoprecipitated and input DNA was subjected to T7 RNA polymerase-based amplification. Labeling, hybridization and washing were carried out according to the Agilent mammalian ChIP-on-chip protocol (ver.9.0). Scanned images were quantified with Agilent Feature Extraction software under standard conditions. Human ES cells were differentiated for 6 days in EBs, then CD34+CD43-CD45- endothelial cells were isolated, plated onto OP9 cells, and transduced with the 4OH-tamoxifen (4OHT)-inducible 3×FLAG-tagged Sox17-ERT retrovirus. The cells were seeded on OP9 stromal cells and cultured in the presence of 4OH-tamoxifen. At day 27 of the co-culture with OP9 cells, CD34+CD43+CD45low hemogenic endothelium-like cells overexpressing Sox17-ERT were collected by CD34 magnetic-activated cell sorting (MACS) and subjected to a ChIP-chip analysis. Less...