In vitro angiogenesis. (A) IHC analysis of vascular endothelial growth factor (VEGF) (brown) expressed by BMSC and HUVEC in monoculture at day 0 in medium Complete EGM2 and at day 2 in media CTR, OM, OM supplemented with COCl2 or DMOG and OM in 1% O2, scale bar 50 μ m. (B) IHC result of VEGF expression by the cocultured cells, scale bar 50 μm. (C) qPCR presents relative gene expression of VEGF and HIF 1α of the cells cocultured in media OM, OM supplemented with COCl2 or DMOG and OM in 1% O2 over time (n = 3, ∗∗ p ≤ 0.0029, ∗∗∗ p = 0.0004, ∗∗∗∗ p < 0.0001). (D) ELISA data shows the concentration of VEGF released in the supernatant by the cocultured cells in three groups: Complete EGM2, CTR, and OM. In each group, the cells were incubated with or without COCl2 or DMOG and in 1% O2 for 24 h then in the medium supplemented with 0.1% FBS only for another 24 h (n = 3, ∗ p < 0.05, ∗∗ p < 0.01).