Knockdown of XIST Attenuates Cerebral Ischemia/Reperfusion Injury Through Regulation of miR-362/ROCK2 Axis

Long non-coding RNAs (lncRNAs) are considered as critical regulators in the pathogenesis of cerebral ischemia. In this present study, we aimed to investigate the impact and underlying mechanism of lncRNA X-inactive specific transcript (XIST) in cerebral ischemia/reperfusion (I/R) injury. An oxygen-glucose deprivation/reperfusion (OGD/R) model in PC12 cells was applied to mimic cerebral I/R injury in vitro and middle cerebral artery occlusion/reperfusion (MCAO/R) model was performed in mice to mimic cerebral I/R injury in vivo. Real-time PCR, fluorescence in situ hybridization (FISH) assay, and western blotting assay were carried out to detect the expression levels of XIST, miR-362, and Rho-related coiled-coil containing protein kinase 2 (ROCK2). The functional experiments were measured by CCK-8 assay, immumofluorescence assay, ELISA assay, TUNEL, and TTC staining. Results displayed that XIST was elevated in PC12 cells with OGD/R, as well as in the ischemic penumbra of mice with MCAO/R. In vitro, knockdown of XIST facilitated cell survival, inhibited apoptosis, and alleviated inflammation injury in OGDR PC12 cells. In vivo, inhibition of XIST remarkably reduced the neurological impairments, promoted neuron proliferation, and suppressed apoptosis in MCAO mice. Mechanistically, XIST acted as a competing endogenous RNA of miR-362 to regulate the downstream gene ROCK2. In conclusion, depletion of XIST attenuated I/R-induced neurological impairment and inflammatory response via the miR-362/ROCK2 axis. These findings offer a potential novel strategy for ischemic stroke therapy.