MicroRNA-25-3p suppresses epileptiform discharges through inhibiting oxidative stress and apoptosis via targeting OXSR1 in neurons.

MicroRNA-25-3p (miR-25-3p) has been reported to be closely related with oxidative stress and apoptosis. Here, we aimed to detect the effects of miR-25-3p in the primarily cultured hippocampal neurons. Kainic acid (KA) was used to induce epileptic seizures in the rats. We predicted that oxidative stress responsive 1 (OXSR1) might be a potential target of miR-25-3p with TargetScan prediction and luciferase assays, and the primarily cultured hippocampal neurons were exposed to Mg2+-free solution for 3 h to induce spontaneous recurrent epileptiform discharges (SREDs). Then, the expression of miR-25-3p and OXSR1 in the rats hippocampi and primarily cultured hippocampal neurons were detected. Those SREDs neurons were treated with miR-25-3p mimic, miR-25-3p inhibitor or/and OXSR1 over-expression vector, and SREDs, oxidative stress and apoptosis were observed. We found down-regulation of miRNA-25-3p and up-regulation of OXSR1 in hippocampi of KA-treated rats and Mg2+-free-treated neurons. MiRNA-25-3p mimic could down-regulate OXSR1 expression, inhibit SREDs, reduce oxidative stress and decrease apoptosis. Additionally, over-expression of OXSR1 weakened those effects of miR-25-3p mimic. Those data indicated that miR-25-3p had anti-epileptic, anti-oxidant and anti-apoptosis effects on the primarily cultured neurons through targeting OXSR1, which provided a novel target for the treatment of epilepsy.