(A) PF-derived exosomes (10 μg/ml) stained using carboxyfluorescein succinimidyl ester (CFSE, in green) were incubated with ECs for 24 hr. Next, cells were stained with phalloidin (red) and DAPI (blue) (the scale bar represents 25 μm). (B and C) Column graphs show (B) EC apoptosis (measured by caspase-3 activity assay) and (C) EC proliferation (measured by BrdU incorporation) after treatment with 10 μg/ml of either PF- exosomes (black columns) or exosome-depleted PF (gray columns). PBS was used as an additional control (open columns); n = 7. (D) Photomicrographs show endothelial network formation on Matrigel (the scale bar represents 200 μm); 2.5× magnification. (E) Bar graphs show Matrigel assay quantification (total length of EC tube-like structures). All values are mean + SEM. *p ≤ 0.05 and ***p ≤ 0.001 versus PBS, # # #p ≤ 0.001 versus PF exosome-free (one-way ANOVA, Dunnett’s post hoc test); n = 6.