The Notch ligand DLL4 specifically marks human hematoendothelial progenitors and regulates their hematopoietic fate

Leukemia. 2015 Aug;29(8):1741-53. doi: 10.1038/leu.2015.74. Epub 2015 Mar 17.


Notch signaling is essential for definitive hematopoiesis, but its role in human embryonic hematopoiesis is largely unknown. We show that in hESCs the expression of the Notch ligand DLL4 is induced during hematopoietic differentiation. We found that DLL4 is only expressed in a sub-population of bipotent hematoendothelial progenitors (HEPs) and segregates their hematopoietic versus endothelial potential. We demonstrate at the clonal level and through transcriptome analyses that DLL4(high) HEPs are enriched in endothelial potential, whereas DLL4(low/-) HEPs are committed to the hematopoietic lineage, albeit both populations still contain bipotent cells. Moreover, DLL4 stimulation enhances hematopoietic differentiation of HEPs and increases the amount of clonogenic hematopoietic progenitors. Confocal microscopy analysis of whole differentiating embryoid bodies revealed that DLL4(high) HEPs are located close to DLL4(low/-) HEPs, and at the base of clusters of CD45+ cells, resembling intra-aortic hematopoietic clusters found in mouse embryos. We propose a model for human embryonic hematopoiesis in which DLL4(low/-) cells within hemogenic endothelium receive Notch-activating signals from DLL4(high) cells, resulting in an endothelial-to-hematopoietic transition and their differentiation into CD45+ hematopoietic cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / metabolism*
  • Cell Differentiation*
  • Cell Proliferation
  • Cells, Cultured
  • Embryoid Bodies
  • Embryonic Stem Cells / cytology*
  • Embryonic Stem Cells / metabolism
  • Endothelium / cytology*
  • Endothelium / metabolism
  • Female
  • Flow Cytometry
  • Gene Expression Profiling
  • Hematopoiesis / physiology*
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Immunoenzyme Techniques
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction


  • Biomarkers
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • RNA, Messenger
  • delta protein