MiRNA-34c-5p protects against cerebral ischemia/reperfusion injury: involvement of anti-apoptotic and anti-inflammatory activities.

MicroRNAs (miRNAs) are known as important regulators of gene expression and play important roles in diverse biological activities. However, the involvement of miRNAs in cerebral ischemia remains elusive. In the present study, using the middle cerebral artery occlusion (MCAO) model and oxygen-glucose deprivation/reperfusion (OGD/RP)-induced cell injury model, we found that the expression levels of miR-34c-5p were significantly reduced in MCAO rats and OGD/RP cells. Overexpression of miR-34c-5p could improve the increased brain infarction, brain water content and neurological scores in MCAO rats, as well as the abnormal expression of inflammatory cytokines (TNF-α, IL-6, COX-2, iNOS, IL-10) in OGD/RP cells. Moreover, overexpression of miR-34c-5p was found to inhibit the activity of nuclear factor-kappa B (NF-κB) by regulating the expression of nuclear receptor coactivator 1 (NCOA1), and increase the apoptotic rate of cortical neurons by inhibiting the expression of Caspase-3 and Bax and upregulating the expression of Bcl-2. Taken together, our findings demonstrated that miR-34c-5p plays an important role in cerebral ischemia/reperfusion injury, which may be mediated through inflammatory and apoptotic signaling pathways.