Apoptosis-induced exosomes from human exfoliated deciduous teeth enhance angiogenesis in human umbilical vein endothelial cells.

Exosomes derived from the stem cells of human exfoliated deciduous teeth (SHED) hold promise for tissue regeneration. Apoptotic cells release a variety of extracellular vesicles that affect intercellular communication. This study aimed to investigate the angiogenic effects of SHED-derived exosomes modified via apoptosis induction on human umbilical vein endothelial cells (HUVECs). Apoptosis was induced in SHED via serum starvation for 3 weeks and confirmed by the upregulation of the apoptotic genes, caspase 3 and 9, and via annexin V staining. The apoptotic SHED-derived exosomes were isolated, characterized, and subjected to proteomic analysis. In vitro experiments were performed to assess the effects of apoptotic SHED exosomes on the proliferation, migration, and tube formation of HUVECs. The apoptosis-induced SHED showed increased cell viability and decreased numbers of dead cells compared with those of conventional cultures while retaining their identity as mesenchymal stem cells positive for CD44, CD73, and CD90. The apoptotic SHED-derived exosomes exhibited characteristic features, such as standard size, cup-shaped morphology, and positive staining, for exosomal markers CD9, CD63, and CD81. Proteins associated with apoptosis, programmed cell death, and cellular senescence were downregulated in the apoptotic SHED exosomes, whereas those associated with extracellular matrix organization were upregulated, indicating positive angiogenesis. HUVECs treated with apoptotic SHED exosomes exhibited significantly enhanced proliferation and migration compared with those treated with normal SHED exosomes. The mesh-like structures in the apoptotic SHED exosomes exhibited significantly increased signs of angiogenesis. The findings of this study provide new insights into the potential use of apoptotic SHED-derived exosomes in regenerative medicine.