Glycogen synthase kinase-3β mediates toll-like receptors 4/nuclear factor kappa-B-activated cerebral ischemia-reperfusion injury through regulation of fat mass and obesity-associated protein

Abstract

BACKGROUND: Glycogen synthase kinase-3β (GSK3β), fat mass and obesity-associated protein (FTO), and toll-like receptors 4 (TLR4) take on critical significance in different biological processes, whereas their interactions remain unclear. The objective was the investigation of the interaction effect in cerebral ischemia-reperfusion (I/R) injury. METHODS: The function of the cerebral cortex in the mouse middle cerebral artery occlusion (MCAO) model (each group n = 6) and P12 cells oxygen-glucose deprivation/reoxygenation (OGD/R) model was analyzed using short hairpin GSK3β lentivirus and overexpression of FTO lentivirus (in vitro), TLR4 inhibitor (TAK242), and LiCl to regulate GSK3β, FTO, TLR4 expression, and GSK3β activity, respectively. RESULTS: After GSK3β knockdown in the OGD/R model of PC12 cells, the levels of TLR4 and p-p65 were lower than in the control, and the level of FTO was higher than in the control. Knockdown GSK3β reversed the OGD/R-induced nuclear factor kappa-B transfer to the intranuclear nuclei. As indicated by the result, TLR4 expression was down-regulated by overexpressed FTO, and TLR4 expression was up-regulated notably after inhibition of FTO with the use of R-2HG. After the inhibition of the activity of GSK3β in vivo, the reduction of FTO in mice suffering from MCAO was reversed. CONCLUSIONS: Our research shows that GSK3β/FTO/TLR4 pathway contributes to cerebral I/R injury.

Keywords

• cerebral ischemia-reperfusion injury
• fat mass and obesity-associated protein
• glucose-oxygen deprivation/reoxygenation
• glycogen synthase kinase-3β
• middle cerebral artery occlusion
• n6-methyladenosine
• nuclear factor kappa-b
• stroke
• toll-like receptors 4