Transcriptomic characterization of different endothelial and stromal cell populations in the bone marrow using in vivo labelling by a CD73-EGFP reporter mouse model. Characterization of bone marrow sinusoidal cells

CD73 is a well-established marker of multipotent stromal cells. We have generated a CD73-EGFP reporter mouse model, which allowed us to identify and track multipotent stromal cells in vivo. We also observed EGFP-labelling of the sinusoidal endothelial cell population, which is suggested to constitute an important component of the hematopoietic stem cell niche in the bone marrow. At the molecular level these bone marrow sinusoidal cells are poorly characterized, because of the lack of appropriate mouse models. Using FACS-based cell sorting we have isolated EGFP+/PECAM1+/CD45- sinusoidal and EGFP-/PECAM1+/CD45- arteriolar endothelial cells as well as EGFP+/PECAM-/CD45- multipotent stromal cells from the bone marrow in biological triplicates and performed RNA-seq transcriptome analysis. This approach enabled the molecular characterization of bone marrow sinusoidal endothelial cells and to compare this with the other two cell populations. These data deepen our understanding of these different cell populations and provide insight into the endothelial heterogeneity within the BM compartment.