MicroRNA-210 targets antiapoptotic Bcl-2 expression and mediates hypoxia-induced apoptosis of neuroblastoma cells

MicroRNAs (miRNAs) can regulate cell survival and death by targeting apoptosis-related gene expression. miR-210 is one of the most hypoxia-sensitive miRNAs. In this study, we evaluated the roles of miR-210 in hypoxia-induced insults to neural cells. Treatment of neuro-2a cells with oxygen/glucose deprivation (OGD) induced cell apoptosis in a time-dependent manner. In parallel, OGD time-dependently increased cellular miR-210 levels. Knocking down miR-210 expression using specific antisenses significantly attenuated OGD-induced neural apoptosis. Concurrently, OGD increased hypoxia-inducible factor (HIF)-1 alpha mRNA and protein syntheses. Pretreatment with YC-1, an inhibitor of HIF-1 alpha, reduced OGD-caused cell death. Sequentially, OGD specifically decreased antiapoptotic Bcl-2 mRNA and protein levels in neuro-2a cells. A search by a bioinformatic approach revealed that miR-210-specific binding elements exist in the 3'-untranslated region of Bcl-2 mRNA. Application of miR-210 antisenses simultaneously alleviated OGD-involved inhibition of Bcl-2 mRNA expression. In comparison, overexpression of miR-210 synergistically diminished OGD-caused inhibition of Bcl-2 mRNA expression and consequently induced greater cellular insults. Taken together, this study shows that OGD can induce miR-210 expression through activating HIF-1 alpha. And miR-210 can mediate hypoxia-induced neural apoptosis by targeting Bcl-2.