Effects of protein kinase inhibitors and vWF on a number of endothelial cells in adhesion wells. HUVECs were pre-incubated with p38 MAPK inhibitor SB203580 (10 μM), its inactive analog SB202474 (10 μM) or the inhibitors of ERK-1,2 phosphorylation, PD98059 (10 μM) or U0126 (10 μM), for 45 minutes and treated with 4 μg/ml vWF for four hours in the presence of the protein kinase inhibitors. The mock adhesion assay was conducted without addition of hMSCs. The number of cells in the wells was assayed using Quanti-iT PicoGreen dsDNA reagent as described in the Materials and Methods. Data are shown as mean ± SD of eight independent measurements. Treatment of HUVECs with protein kinase inhibitors and vWF had no significant effect on a number of endothelial cells in adhesion wells (t-test, P-value >0.05).