Apoptotic vesicles from endothelial cells promote endothelial progenitor cell differentiation and angiogenesis via miR-30a-5p mediated activation of the EGFR/PI3K/AKT/VEGF pathway.

[BACKGROUND] Endothelial cells (ECs) are crucial for tissue repair and wound healing but are prone to damage and apoptosis. When tissues or blood vessels are injured, endothelial progenitor cells (EPCs) are quickly activated, home to the site, and differentiate into ECs for endothelial integrity restoration. Apoptotic extracellular vesicles (Apo-EVs), released during apoptosis, have been found to regulate the micro environment, mediate intercellular communication, and participate in tissue repair, yet there's a lack of research on how EC-derived Apo-EVs, as intercellular communication media-tors, regulate EPCs' differentiation into ECs and promote angiogenesis and wound re-pair. Therefore, this study aims to explore whether EC-derived Apo-EVs can promote the differentiation of EPCs into ECs, facilitating wound angiogenesis, and to deeply analyze the underlying molecular mechanisms and key signaling pathways.

[METHODS] Human embryonic stem cells were differentiated into endothelial progenitor cells (EPCs) and endothelial cells (ECs), followed by phenotypic characterization. ECs were induced to undergo apoptosis for isolating EC-derived apoptotic extracellular vesicles (EC-Apo-EVs), which were co-cultured with EPCs to evaluate their pro-differentiation capacity. Integrative analysis of EPC transcriptome and EC-Apo-EV miRNA sequencing identified key mediating miRNAs and signaling pathways, validated in vitro. A murine skin wound model was established (randomized into control, EC-Apo-EV, and positive control groups) to assess EC-Apo-EVs' therapeutic efficacy in wound healing.

[RESULTS] In this study, we induced ECs apoptosis, extracted Apo-EVs for promoting angiogenesis and wound repair. The isolated Apo-EVs showed excellent ability to promote EPCs differentiation and angiogenesis in vitro and in vivo. In wound healing, Apo-EVs outperformed the positive control group. Mechanistically, miR-30a-5p in Apo-EVs inhibits Promyelocytic Leukemia (PML), activating the Epidermal Growth Factor Receptor/Phosphatidylinositol 3-Kinase/Protein Kinase B/Vascular Endothelial Growth Factor (EGFR/PI3K/AKT/VEGF) pathway in EPCs and exerting biological effects.

[CONCLUSION] EC-derived Apo-EVs demonstrated excellent capacity to promote EPCs differentiation and angiogenesis both in vitro and in vivo, the mechanism is associated with miR-30a-5p within the vesicles inhibiting PML and activating the EGFR/PI3K/AKT/VEGF signaling pathway. This finding provides a new perspective for revealing the role of EC-derived Apo-EVs in tissue repair and offers potential strategies for the treatment of related diseases.