Role of Exosomal miR-205-5p Cargo in Angiogenesis and Cell Migration.

Exosomes or small extracellular vesicles (sEVs) represent a pivotal component in intercellular communication, carrying a diverse array of biomolecules. Several factors can affect sEVs release dynamics, as occurs in hyperglycemia or inflammation. In fact, sEVs release has been associated with the promotion of physio-pathological processes. Among the sEVs cargo, microRNAs play an essential role in cell-to-cell regulation. More concretely, miR-205-5p is related to angiogenesis and cell proliferation. The aim of this study is to understand the specific role of sEVs containing miR-205-5p under high glucose conditions. ARPE-19 cells were cultured with high glucose (HG) for 5 days. sEVs were isolated and characterized. sEVs from ARPE-19 were used for angiogenesis and cell proliferation. HG increased sEVs release but downregulated miR-205-5p cargo expression compared to the control. sEVs from HG-treated ARPE-19 cells promoted tube formation and migration processes. In contrast, miR-205-5p overexpression (by mimic transfection) decreased angiogenesis and cell migration. Our results demonstrate how ARPE-19 cells respond to HG challenge by increasing sEVs with weak miR-205-5p cargo. The absence of this miRNA in sEVs is enough to promote angiogenesis. In contrast, restoring sEVs-miR-205-5p levels decreased it. These findings open new possibilities in sEVs-based therapies containing miR-205-5p against angiogenesis.

Oxidative-Induced Angiogenesis Is Modulated by Small Extracellular Vesicle miR-302a-3p Cargo in Retinal Pigment Epithelium Cells.

Extracellular vesicles are released from cells under diverse conditions. Widely studied in cancer, they are associated with different diseases playing major roles. Recent reports indicate that oxidative damage promotes the release of small extracellular vesicle (sEVs) from the retinal pigment epithelium (RPE), with an angiogenic outcome and changes in micro-RNA (miRNA) levels. The aim of this study was to determine the role of the miRNA miR-302a-3p, included within RPE-released sEVs, as an angiogenic regulator in cultures of endothelial cells (HUVEC). ARPE-19 cell cultures, treated with H2O2 to cause an oxidative insult, were transfected with a miR-302a-3p mimic. Later, sEVs from the medium were isolated and added into HUVEC or ARPE-19 cultures. sEVs from ARPE-19 cells under oxidative damage presented a decrease of miR-302a-3p levels and exhibited proangiogenic properties. In contrast, sEVs from miR-302a-3p-mimic transfected cells resulted in control angiogenic levels. The results herein indicate that miR-302a-3p contained in sEVs can modify VEGFA mRNA expression levels as part of its antiangiogenic features.