Role of exosomal miR-205-5p in angiogenesis and migration

Abstract

Purpose : Small extracellular vesicles (sEVs) represent a pivotal component in intercellular communication, carrying a diverse array of biomolecules. The dynamics of sEVs release are significantly influenced by the cellular microenvironment such as high glucose (HG). This phenomenon has been associated with the promotion of pathological processes. This study aims to understand the role of miR-205-5p in extracellular vesicles under hyperglycemic conditions and its effect on angiogenesis and cell migration.

Methods : ARPE-19 cells were cultured during 5 days with 35 mM glucose and then transfected with miR-205-5p mimic after 48 h cell culture medium was collected for sEVs isolation. The expression of miR-205-5p was detected with RT-qPCR. ARPE-19 and HUVEC cells were treated with sEVs to observe migration and angiogenesis processes. The sEVs were characterized using Nanosight, Western Blot, transmission electron microscopy (TEM), and stained with PKH26 for fluorescence internalization.

Results : After 35 mM glucose treatment for 5 days, ARPE-19 cells released a significantly higher number of sEVs (3.74e 008 ± 1.30e 008 particles/ml). HUVEC cells treated with control sEVs exhibited lower uptake compared to cells treated with sEVs from 35 mM glucose conditions at 8 hours (p 0.045) and 12 hours (p 0.003). Exposure to HG downregulated miR-205-5p expression in extracellular vesicles compared to control. Mimic transfection of this miRNA restores the values in HG conditions. HUVEC tube-formation was significantly increased by HG-sEVs from ARPE-19 (139.90 ± 7.09). This effect was attenuated by miR-205-5p mimic in sEVs 35 mM glucose+ mimic miR-205-5p (97.41 ± 6.70). In the wound healing assay, ARPE-19 cells with HG-induced sEVs (49.33 ± 15.88) showed faster wound closure compared to cells treated with control sEVs (31.75 ± 13.88), this effect was normalized by ectopic addition of miR-205-5p resulting in less migration in both conditions.

Conclusions : Our results demonstrate how ARPE-19 cells respond to high glucose challenges by increasing sEVs with low miR-205-5p content. The presence of this miRNA in sEVs can inhibit angiogenesis and migration opening new doors in cell-to-cell communication mediated by extracellular vesicles.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.