Figure 1: Influence of b-EVs and FGF-EVs on angiogenic properties of HMEC. A, B, C: representative images of HMEC in vitro vessel-like structure formation on Matrigel, (A) without stimulation (control), (B) with b-EV stimulation, or (C) with FGF-EV stimulation; D, E, F : representative in vivo vessel formation by HMEC within Matrigel (sections stained by trichrome method; arrows indicate red blood cell containing vessels); insert shows staining for human CD31 (green) and for mouse smooth muscle actin (red, white arrows); (D) non-stimulated HMEC (control); (E) HMEC stimulated with b-EVs; (F) HMEC stimulated with FGF-EVs. (G) diagram of number and size of in vitro formed vessel-like structures in control and in response to b-EVs or FGF-EVs stimulation (mean ± SEM, * - p<0,05 vs. “control”, ^ p<0,05 vs. “+b-EVs”, n=15); (H) diagram of quantity and size of vessels formed within Matrigel by stimulated or non-stimulated HMEC (mean±SEM, * - p<0.05 vs. “control”, ^ p<0.05 vs. “+b-EVs”, n=10).