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

S.-W. Wang, L.-X. Deng, H.-Y. Chen, Z.-Q. Su, S.-L. Ye, W.-Y. Xu

Department of Neurology, the Third Hospital of Xiamen, Xiamen, Fujian, China. wenyongxuee@126.com

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• Neurology

OBJECTIVE: 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.

MATERIALS AND METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.

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