MicroRNA-146a protects against intracerebral hemorrhage by inhibiting inflammation and oxidative stress.

The present study aimed to investigate the role of microRNA-146a (miR-146a) in intracerebral hemorrhage (ICH), and to further assess its underlying mechanism. An ICH rat model was established in the current study and 1 h following ICH induction, rats were treated with or without an miR-146a mimic. A total of 3 days following ICH induction, rat neurological score, brain water content and neuronal apoptosis were measured via flow cytometry. Levels of pro-inflammatory cytokines tumor necrosis factor-alpha and interleukin-1 beta were detected via ELISA and certain biomarkers of oxidative stress, including malondialdehyde, superoxide dismutase and glutathione peroxidase, were also determined in current study. The expression of genes and proteins were detected in current study via reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. MicroRNA.org software and a dual luciferase reporter assay were used to confirm the association between miR-146a and TRAF6. The results of the current study revealed that miR-146a was significantly downregulated in ICH rats, and its overexpression reduced neurological damage and brain edema, as evidenced by decreased neurological scores and brain water content. Results from further analyses demonstrated that the overexpression of miR-146a inhibited neuronal apoptosis, reduced pro-inflammatory cytokine production and prevented oxidative stress in ICH rats. In addition, it was revealed that the upregulation of miR-146a repressed the TRAF6/NF-kappa B pathway in the brain tissue of ICH rats. TRAF6 was also determined to be a target of miR-146a. In conclusion, these data indicated that miR-146a protects against ICH by inhibiting inflammation and oxidative stress.