Exosome-encapsulated miR-505 from ox-LDL-treated vascular endothelial cells aggravates atherosclerosis by inducing NET formation

Exosome-encapsulated miR-505 from ox-LDL-treated vascular endothelial cells aggravates atherosclerosis by inducing NET formation:

Abstract

Neutrophil extracellular traps (NETs) play an important role in the pathological process of atherosclerosis (AS). This study aims to evaluate whether exosomes from oxidized low-density lipoprotein (ox-LDL)-treated vascular endothelial cells (VECs) aggravate AS by inducing NET formation. Exosomes from the peripheral blood of healthy donors and AS patients (namely NC-EXO and AS-EXO, respectively) and exosomes from human umbilical vein endothelial cells (HUVECs) treated without or with ox-LDL (namely normal EXO and ox-LDL-EXO, respectively) were isolated, identified, and co-cultured with neutrophils from peripheral blood of healthy donors. NET formation was evaluated by immunofluorescence staining and determining the content of cell-free DNA and myeloperoxidase-DNA complex. Dual-luciferase reporter assay, chromatin immunoprecipitation assay, quantitative reverse transcription polymerase chain reaction, and western blot analysis were performed to explore the underlying mechanisms. We found that AS-EXO and ox-LDL-EXO induced NET release from neutrophils. Mechanistically, ox-LDL treatment in HUVECs might activate the NF-κB pathway, which transcriptionally activates miR-505, and then the exosome-encapsulated high miR-505 expression targeted and inhibited SIRT3 in neutrophils, thereby inducing reactive oxygen species (ROS) level increase and NET release by neutrophils. Further in vivo experiments showed that ox-LDL-EXO accelerated AS progression in AS mice. In summary, exosome-encapsulated miR-505 from ox-LDL-treated VECs aggravates AS by inducing NET formation.