Fig. 3

UCMSCs-exo/eNOS counteract oxidative damage and restore biological functions in fibroblasts and vascular endothelial cells treated with high glucose. HG: complete medium containing 50 mM glucose. UCMSCs-exo: supplemented with 20 μg of UCMSCs-exo in complete medium containing 50 mM glucose. UCMSCs-exo/eNOS: supplemented with 20 μg of UCMSCs-exo/eNOS in complete medium containing 50 mM glucose. a Proliferation of HUVECs incubated with HG, UCMSCs-exo, and UCMSCs-exo/eNOS for 12, 24, 36 and 48 h (n = 3, two-tailed Student’s t-test). b Proliferation of fibroblasts incubated with HG, UCMSCs-exo, and UCMSCs-exo/eNOS for 12, 24, 36, and 48 h (n = 3, two-tailed Student’s t-test). c Representative micrographs showing the effect of UCMSCs-exo versus UCMSCs-exo/eNOS on Transwell migration of fibroblasts and HUVECs in high-glucose culture conditions. Scale bar: 200 μm. d Quantitative analysis of Transwell assay of fibroblasts (n = 3, two-tailed Student’s t-test). e Quantitative analysis of Transwell assay of HUVECs (n = 3, two-tailed Student’s t-test). f, g Histograms showing malondialdehyde (MDA) contents of HUVECs and fibroblasts in the Control, HG, UCMSCs-exo, and UCMSCs-exo/eNOS groups (n = 3, two-tailed Student’s t-test). h, i Histograms showing superoxide dismutase (SOD) activities in HUVECs and fibroblasts in the Control group, HG group, UCMSCs-exo group, and UCMSCs-exo/eNOS group (n = 3, two-tailed Student’s t-test). j, k Histograms showing the glutathione (GSH) contents of HUVECs and fibroblasts in the Control group, HG group, UCMSCs-exo group, and UCMSCs-exo/eNOS group (n = 3, two-tailed Student’s t-test). l Representative images of tube formation assays of HUVECs treated with HG, UCMSCs-exo, or UCMSCs-exo/eNOS on Matrigel. Scale bar: 200 μm. m Quantitative analysis of tube lengths and branching points in tube formation assays. (Each group was set up with three replicates, and no fewer than six outcomes per group were included in the statistics. Mann–Whitney U test). Data represent means ± SD. *p < 0.05, **p < 0.01, ***p < 0.001 vs. HG group; #p < 0.05, ##p < 0.01, ###p < 0.001 vs. UCMSCs-exo group