Exosomes Derived from Human Umbilical Vein Endothelial Cells Promote Proliferation and Migration of Endothelial Cells In Vitro

Chronic limb-threatening ischemia (CLTI), which is characterized by blockages in peripheral arteries, is becoming more common, but recent therapy results in high rate of amputation and mortality. As a potential novel therapy, exosomes derived from human umbilical vein endothelial cells (HUVECs) may enhance angiogenesis process as a counter for CLTI pathogenesis that is indicated by amplified endothelial proliferation and migration rates in vitro. Exosomes from HUVEC were isolated and characterized. The effect of exosomes in different particle numbers (1, 0.5, and 0.1%) on proliferation was studied by MTT assay, and the effect on migration was studied by wound healing assay. The exosomes had ranged in size from approximately 30 to 150 nm with a total yield 5 × 106 particles/mL. They expressed CD63+ and CD81 + . Both 1 and 0.5% exosomes HUVECs could enhance the proliferation of endothelial cells significantly compared with control group (p < 0.05) at 24 hours. At 72 hours, all groups treated with exosomes exhibited significantly heightened endothelial proliferation in contrast to the control group (p < 0.05). Yet, no substantial variances were observed among the diverse exosome treatment groups (p > 0.05). A total of 1% exosomes HUVECs could significantly promote the migration of endothelial cells compared with controls (p < 0.05) at 24 and 48 hours. Exosomes from HUVECs enhance the proliferation and migration of endothelial cells, suggesting they might stimulate angiogenesis even at relatively low concentrations (5 × 105 particles/mL). Additional research is crucial to understand the precise mechanisms through which HUVEC-derived exosomes facilitate angiogenesis to develop effective exosome-based therapies for vascular conditions, especially CLTI.