LncRNA GAS5 Silencing Attenuates Oxygen-Glucose Deprivation/Reperfusion-Induced Injury in Brain Microvascular Endothelial Cells via miR-34b-3p-Dependent Regulation of EPHA4.

Background: The aim of our study was to explore the role of long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) in ischemic stroke using oxygen-glucose deprivation/reperfusion (OGD/R)-induced bEnd.3 cells as in vitro cell model.

Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were adopted to analyze RNA and protein expression. Cell viability and apoptosis were analyzed by Cell Counting Kit-8 (CCK8) assay and flow cytometry. The levels of nitric oxide (NO) and endothelin-1 (ET-1) in culture supernatant were examined by their matching commercial kits. The intermolecular target interaction was predicted by starBase software and tested by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

Results: OGD/R-induced apoptosis and dysregulation in vascular endocrine system were largely alleviated by the knockdown of GAS5. GAS5 interacted with microRNA-34b-3p (miR-34b-3p), and GAS5 silencing protected bEnd.3 cells from OGD/R-induced injury partly through up-regulating miR-34b-3p. EPH receptor A4 (EPHA4) was a target of miR-34b-3p. GAS5 acted as the molecular sponge of miR-34b-3p to up-regulate EPHA4 in bEnd.3 cells. GAS5 interference protected against OGD/R-induced damage in bEnd.3 cells partly through down-regulating EPHA4.

Conclusion: LncRNA GAS5 knockdown protected brain microvascular endothelial cells bEnd.3 from OGD/R-induced injury depending on the regulation of miR-34b-3p/EPHA4 axis.