Abstract: Objective To explore the role of miR-378 in oxygen-glucose deprivation (OGD)-induced N2A cell ischemic injury and its possible molecular mechanism. Methods 3h OGD/24h reoxygenation of N2A cells was established to mimic ischemia/reperfusion in vitro, and the N2A cell survival rate was determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The caspase-3 protein levels, and the expression levels of miR-378 and caspase-3 mRNA were determined by using the techniques of Western blot and real time RT-PCR, respectively. Luciferase reporter assay was performed to identify the direct binding of miR-378 with 3＇-UTR of caspase-3 mRNA. Results The miR-378 expression levels decreased significantly (p<0.05, n=5 group) in response to reoxygenation time following 3h OGD treatment in N2A cells. Under the condition of 3h OGD/24h reoxygenation not non-OGD, up- and down-regulation of miR-378 expression level by transfection with pri-miR-378 or anti-miR-378 could enhance and reduce N2A cell survival rate (p<0.05, n=6), respectively. Similarly, miR-378 could negatively regulate caspase-3 protein expression levels, but no significant affection on caspase-3 mRNA expression levels was observed in N2A cells after 3h OGD/24h reoxygenation treatment. In addition, overexpression of miR-378 by co-transfection with pri-miR-378 could significantly decrease the luciferase activities which were expressed by plasmid containing 3＇-UTR of caspase-3 mRNA in N2A cells (p<0.05, n=6). Conclusions miR-378 attenuates OGD-induced N2A cell ischemic injuries by negatively regulating caspase-3 protein expression, which may provide a potential therapeutic target for ischemic stroke in miRNAs levels.

Key words: Keywords: Oxygen-glucose deprivation (OGD), Ischemic injury, miR-378, Caspase-3, N2A cells