Expression of endothelial cell marker—VWF. (A) IHC analysis of VWF 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 μm, inset scale bar 25 μ m. (B) IHC analysis of VWF expression by cocultured cells in different conditions at day 2 and day 9, scale bar 50 μ m. (C) Relative gene expression of VWF shown by qPCR (n = 3, ∗ p ≤ 0.0228, ∗∗ p ≤ 0.0057, ∗∗∗ p = 0.0006). (D) Quantification of VWF released to the medium performed by the ELISA method. The cells were incubated in media Complete EGM2, CTR and OM in the presence/absence of COCl2 or DMOG for 24 h followed by another 24 h in the medium containing 0.1% FBS only (n = 3, p > 0.05).