Long Non-Coding KCNQ1OT1 Promotes Oxygen-Glucose-Deprivation/Reoxygenation-Induced Neurons Injury Through Regulating MIR-153-3p/FOXO3 Axis.

BACKGROUND: Long non-coding RNAs (LncRNAs) have been reported to play important roles in the pathogenesis and development of many diseases, including cerebral ischemia and reperfusion (I/R) injury. In this study, we aimed to investigate the role of LncRNA-Potassium Voltage-Gated Channel Subfamily Q Member 1 opposite strand/antisense transcript 1 (KCNQ1OT1) in cerebral I/R induced neuronal injury, and its underlying mechanisms. METHODS: Primary mouse cerebral cortical neurons treated with oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro and mice subjected to middle cerebral artery occlusion (MCAO) and reperfusion were used to mimic cerebral I/R injury. Small inference RNA (siRNA) was used to knockdown KCNQ1OT1 or microRNA-153-3p (miR-153-3p). Dual-luciferase assay was performed to detect the interaction between KCNQ1OT1 and miR-153-3p and interaction between miR-153-3p and Fork head box O3a (Foxo3). Flow cytometry analysis was performed to detect neuronal apoptosis. qRT-PCR and Western blotting were performed to detect RNA and protein expressions. RESULTS: KCNQ1OT1 and Foxo3 expressions were significantly increased in neurons subjected to I/R injury in vitro and in vivo, and miR-153-3p expression were significantly decreased. Knockdown of KCNQ1OT1 or overexpression of miR-153-3p weakened OGD/R-induced neuronal injury and regulated Foxo3 expressions. Dual-luciferase analysis showed that KCNQ1OT1 directly interacted with miR-153-3p and Foxo3 is a direct target of miR-153-3p. CONCLUSIONS: Our results indicate that LncRNA-KCNQ1OT1 promotes OGD/R-induced neuronal injury at least partially through acting as a competing endogenous RNA (ceRNA) for miR-153-3p to regulate Foxo3a expression, suggesting LncRNA-KCNQ1OT1 as a potential therapeutic target for cerebral I/R injury.

YY1/LncRNA GAS5 complex aggravates cerebral ischemia/reperfusion injury through enhancing neuronal glycolysis.

Yin-Yang 1 (YY1) has been identified as playing critical roles in multiple diseases. However, little is known regarding its roles and mechanisms in cerebral ischemia/reperfusion (I/R) injury. This study is aimed to explore the roles of YY1 in regulating neuronal apoptosis in cerebral I/R injury and its underlying mechanisms. Primary mouse cerebral cortical neurons were isolated and subjected to OGD/R to mimic cerebral I/R injury in vitro. The roles of YY1 on OGD/R-induced neuronal injury were investigated by performing western blotting, quantitative real-time polymerase chain reaction, TUNEL, RNA-binding protein immunoprecipitation, chromatin immunoprecipitation, chromatin isolation by RNA purification assay, glucose uptake assay, lactate production assay, and extracellular acidification rate assay. YY1-binding long non-coding RNAs (LncRNAs) in neurons subjected to OGD/R were identified by RIP and RNA sequencing. The roles of YY1 on cerebral I/R in vivo were detected by assessing neuronbehaviour, infarct size, and neuronal apoptosis. We found that YY1 expression is downregulated, and LncRNA GAS5 is upregulated in neurons subjected to OGD/R. OGD/R treatment promotes YY1 interacting with GAS5 in neurons, and YY1 negatively regulates GAS5 expression by binding to GAS5 promoter to repress its transcription. Besides, YY1 and GAS5 bind to the same region of PFKFB3 promoter to promote PFKFB3 expression and strengthen neuronal glycolysis, resulting in aggravating OGD/R-induced neuronal apoptosis. Knockdown of YY1 or GAS5 protects against I/R-induced ischemic brain damage and improves overall neurological functions in vivo. Overall, YY1 interacts with LncRNA GAS5 to promote PFKFB3 transcription to enhance neuronal glycolysis, resulting in aggravating cerebral I/R injury.