MiR-124 affects the apoptosis of brain vascular endothelial cells and ROS production through regulating PI3K/AKT signaling pathway.

Abstract

The apoptosis of vascular endothelial cells (VEC) is related to ischemic stroke. Phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT/PKB) signaling pathway can upregulate Bcl-2 expression, reduce reactive oxygen species (ROS) production, and induce apoptosis. The level of miR-124 was significantly increased after cerebral ischemia. This study aimed to investigate the role of miR-124 in regulating PI3K expression, brain VEC apoptosis, and ROS production. The expressions of miR-124, PI3K, p-AKT, and Bcl-2 in brain VEC of rats from the sham group and middle cerebral artery occlusion (MCAO) group were tested. Bioinformatics analysis showed the complementary binding site between miR-124 and PI3K mRNA. ROS content and cell apoptosis were detected by flow cytometry. Rat brain VEC were cultured in vitro and treated by oxygen-glucose deprivation (OGD) for 6 h. VECs were divided into four groups, including miR-NC, miR-124 inhibitor, pIRES2-blank, and pIRES2-PI3K groups, and were further treated by OGD. MiR-124 expression, ROS content, and cell apoptosis were markedly increased, whereas the levels of PI3K, p-AKT, and Bcl-2 were markedly reduced in rat VECs from MCAO group compared with that in the sham group. OGD treatment significantly induced VECs apoptosis, upregulated miR-124 expression and ROS content, and down-regulated the levels of PI3K, p-AKT, and Bcl-2. MiR-124 inhibitor or transfection of pIRES2-PI3K plasmid apparently enhanced PI3K, p-AKT, and Bcl-2 expressions, alleviated cell apoptosis and decreased ROS content in VECs induced by OGD. Our data demonstrated that miR-124 induced the apoptosis of brain vascular endothelial cells via the down-regulation of PI3K/AKT signaling pathway and promotion of ROS production.