MicroRNA miR-505-5p Promotes Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury via Negative Regulation of CREG1 in Cultured Neuron-Like Cells

Cerebral ischemia/reperfusion (I/R) injury is associated with various cardiovascular and cerebrovascular diseases with high disability, morbidity, and mortality rates. MicroRNAs (miRNAs) are related to the pathogenesis of the above diseases. MiR-505-5p, a kind of such miRNAs, was found to be highly expressed in cerebral I/R injuries, but the mechanism of action of this miRNA in cerebral I/R injury was unclear. In our study, up-regulation of miR-505-5p was detected in cultured oxygen-glucose deprivation/reoxygenation (OGD/R)-subjected PC12 and HEC293 cells. Silencing of miR-505-5p in OGD/R-affected neuron-like cells not only decreased the OGD/R-injury (according to cell viability, SOD increase, and LDH and MDA decreases), but also reduced apoptosis (decreasing the cleaved caspase-3 and PARP protein levels). Interestingly, expression of CREG1 (Cellular Repressor of E1Astimulated Genes 1) was low in OGD/R-subjected neurons; it was verified as a possible target gene of miR-505-5p. CREG1 knockdown can reverse the effect of miR-505-5p silencing in OGD/R-induced neural injury. Taken together, the data obtained provide a new target for cerebral I/R injury treatment.