In Vivo Labeling by CD73 Marks Multipotent Stromal Cells and Highlights Endothelial Heterogeneity in the Bone Marrow Niche

Cell Stem Cell. 2018 Feb 1;22(2):262-276.e7. doi: 10.1016/j.stem.2018.01.008.


Despite much work studying ex vivo multipotent stromal cells (MSCs), the identity and characteristics of MSCs in vivo are not well defined. Here, we generated a CD73-EGFP reporter mouse to address these questions and found EGFP+ MSCs in various organs. In vivo, EGFP+ mesenchymal cells were observed in fetal and adult bones at proliferative ossification sites, while in solid organs EGFP+ cells exhibited a perivascular distribution pattern. EGFP+ cells from the bone compartment could be clonally expanded ex vivo from single cells and displayed trilineage differentiation potential. Moreover, in the central bone marrow CD73-EGFP+ specifically labeled sinusoidal endothelial cells, thought to be a critical component of the hematopoietic stem cell niche. Purification and molecular characterization of this CD73-EGFP+ population revealed an endothelial subtype that also displays a mesenchymal signature, highlighting endothelial cell heterogeneity in the marrow. Thus, the CD73-EGFP mouse is a powerful tool for studying MSCs and sinusoidal endothelium.

Keywords: bone marrow; endothelial cell heterogeneity; multipotent stromal cells; sinusoidal endothelial cells; stem cell niche.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5'-Nucleotidase / metabolism*
  • Animals
  • Bone Marrow / metabolism
  • Bone Marrow Cells / cytology
  • Bone Marrow Cells / metabolism*
  • Chondrogenesis
  • Endothelial Cells / cytology
  • Endothelial Cells / metabolism*
  • Female
  • Genes, Reporter
  • Green Fluorescent Proteins / metabolism
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Multipotent Stem Cells / cytology
  • Multipotent Stem Cells / metabolism*
  • Organ Specificity
  • Staining and Labeling*
  • Stem Cell Niche*
  • Stromal Cells / cytology
  • Stromal Cells / metabolism


  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • 5'-Nucleotidase