Differentiation and expansion of endothelial cells from human bone marrow CD133[sup +] cells.

We report a method of purifying, characterizing and expanding endothelial cells (ECs) derived from CD133[sup +] bone marrow cells, a subset of CD34[sup +] haematopoietic progenitors. Isolated using immunomagnetic sorting (mean purity 90 ± 5%), the CD133[sup +] bone marrow cells were grown on fibronectin-coated flasks in M199 medium supplemented with fetal bovine serum (FBS), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and insulin growth factor (IGF-1). The CD133[sup +] fraction contained 95 ± 4% CD34[sup +] cells, 3 ± 2% cells expressing VEGF receptor (VEGFR-2/KDR), but did not express von Willebrand factor (VWF), VE-cadherin, P1H12 or TE-7. After 3 weeks of culture, the cells formed a monolayer with a typical EC morphology and expanded 11 ± 5 times. The cells were further purified using Ulex europaeus agglutinin-1 (UEA-1)-fluorescein isothiocyanate (FITC) and anti-FITC microbeads, and expanded with VEGF for a further 3 weeks. All of the cells were CD45[sup -] and CD14[sup -], and expressed several endothelial markers (UEA-1, VWF, P1H12, CD105, E-selectin, VCAM-1 and VE-cadherin) and typical Weibel–Palade bodies. They had a high proliferative potential (up to a 2400-fold increase in cell number after 3 weeks of culture) and the capacity to modulate cell surface antigens upon stimulation with inflammatory cytokines. Purified ECs were also co-cultivated with CD34[sup +] cells, in parallel with a purified fibroblastic cell monolayer. CD34[sup +] cells (10 × 10[sup 5]) gave rise to 17 951 ± 2422 CFU-GM colonies when grown on endothelial cells, and to 12 928 ± 4415 CFU-GM colonies on fibroblast monolayers. The ECs also supported erythroid blast-forming unit (BFU-E) colonies better. These results suggest that bone marrow CD133[sup +] progenitor cells can give rise to highly purified ECs, which have a high proliferative capacity, can be activated by inflammatory cytokines and are super... [ABSTRACT FROM AUTHOR]