Fig. 1

Small molecule-treated MSCs (iMDFECs) change cell type-specific marker expression and gain angiogenic ability in vitro. a Immunocytochemical monitoring of MSCs treated with SB (1 μM, every 3 days). CD90 and CD31 were used as representative markers of MSCs and ECs, respectively. Scale bar = 50 μm. Fluorescence intensities are quantified on the upper right side. *P < 0.05. b EC marker gene expression in iMDFECs. mRNA expression levels of CD34, eNOS, VE-cadherin, VCAM-1, and Flk-1 were measured by using reverse transcription-polymerase chain reaction. GAPDH was used for normalization. *P < 0.05. c Flk-1 and Ace-α-tubulin expressions in iMDFECs. *P < 0.05. d After 16 days of treatment, iMDFECs were re-seeded and stimulated with vascular endothelial growth factor (VEGF) (20 nM) for 24 h. The angiogenic ability (tube formation; total tube length) of iMDFECs was compared with that of control MSCs. Scale bar = 400 μm. *P < 0.05. e Cells were stimulated with 5 μM acetylcholine for 60 min, and the media were collected and subjected to an NO release fluorometric assay. Data represent mean ± standard deviation of at least three independent experiments. EC endothelial cell, eNOS endothelial nitric oxide synthase, Flk-1 vascular endothelial growth factor receptor 1, GAPDH glyceraldehyde 3-phosphate dehydrogenase, iMDFEC induced mesenchymal stem cell-derived functional endothelial cell, MSC mesenchymal stem cell, NO nitric oxide, SB SB216763, VCAM-1 vascular cell adhesion molecule 1, VE-cadherin vascular endothelial cadherin