MiR-1224 downregulation inhibits OGD/R-induced hippocampal neuron apoptosis through targeting Ku protein.

Ischemic cerebrovascular disease is the main cause of disability due to stroke. This study aimed to investigate the function of miR-1224 in OGD/R-induced hippocampal neuron apoptosis, as well as the regulatory mechanism of miR-1224 in ischemic cerebrovascular disease. The oxygen-glucose deprivation/reperfusion (OGD/R) model of primary mouse hippocampal neurons was established. RT-qPCR detected miR-1224, Ku70 and Ku86 levels. Western blotting was applied to measure the expression of Ku70/86 and apoptosis related proteins. Flow cytometry was used to assess apoptosis. JC-1 fluorescence was performed to test the mitochondrial membrane potential (MMP) in neurons. The double luciferase reporter assay was performed to investigate the relationship between miR-1224 and Ku70/86. OGD/R induced the apoptosis and mitochondrial injury in neuronal cells, while miR-1224 downregulation or Ku70/86 upregulation reversed this phenomenon. Meanwhile, miR-1224 negatively regulated the expression of Ku70/86 in neuronal cells through directly targeting Ku70/86. Furthermore, knockdown of Ku70/86 significantly reversed the inhibitory effect of miR-1224 silencing on apoptosis and mitochondrial injury in OGD/R-treated neuronal cells. Our findings indicated that miR-1224 downregulation suppressed OGD/R-induced hippocampal neuron apoptosis by targeting Ku protein, suggesting that miR-1224 could serve as a new target for ischemic cerebrovascular disease treatment.