Volatile anesthetic post-treatment induces protection via inhibition of glycogen synthase kinase 3β in human neuron-like cells

摘要

Application of the volatile anesthetic isoflurane during the early phase of reperfusion reduces ischemic heart and brain injury (anesthetic postconditioning). We hypothesize that inhibition of glycogen synthase kinase 3β (GSK3β), a protein whose activation can lead to cell death, participates in anesthetic postconditioning-induced neuroprotection. SH-SY5Y cells, a human neuroblastoma cell line, were induced by retinoic acid to differentiate into terminal neuron-like cells. The cells then were subjected to a 1-h oxygen-glucose deprivation (OGD), a condition to simulate ischemia in vitro, and a 20-h simulated reperfusion. Isoflurane, sevoflurane or desflurane, three commonly used volatile anesthetics, was applied for 1 h during the early phase of simulated reperfusion. Cell injury was quantified by lactate dehydrogenase (LDH) release. Phospho-GSK3β at Ser9 and total GSK3β were quantified at 1 or 3 h after the OGD. OGD increased LDH release, suggesting that OGD induced cell injury. Post-treatment with isoflurane, sevoflurane or desflurane reduced this cell injury. This protection was apparent when 2% isoflurane was applied within 1 h after the onset of reperfusion. Isoflurane post-treatment also significantly increased the phosphorylation of GSK3β at Ser9 at 1 h after the OGD. GSK3β inhibitors reduced OGD and simulated reperfusion-induced LDH release. The combination of GSK3β inhibitors and isoflurane postconditioning did not cause a greater protection than isoflurane postconditioning alone. These results suggest that volatile anesthetic postconditioning reduces OGD and simulated reperfusion-induced cell injury. Since phospho-GSK3β at Ser9 decreases GSK3β activity, our results suggest that volatile anesthetic postconditioning in human neuron-like cells may be mediated by GSK3β inhibition.