Ischemic postconditioning alleviates ischemia/reperfusion-induced injury in SH-SY5Y cells: development of an in vitro model of ischemic postconditioning

Objective: Ischemic postconditioning (IPC) is shown to reduce ischemia/reperfusion-induced injury. However, the neuroprotective mechanisms of IPC are largely unclear, and animals or cultured neurons are being used to model the process of IPC, which is costly and unstable. This study was conducted to develop an in vitro IPC model of human neuroblastoma cells (SH-SY5Y cells) for studying the IPC mechanism. Methods: The SH-SY5Y cells were divided into 5 groups: the control group, the ischemia/reperfusion group, and the IPC1, 2, and 3 groups. The ischemia/reperfusion group was subjected to 12-h of oxygen glucose deprivation (OGD). After a 12-h OGD, the cells were cultured in 1 (IPC1) to 3 (IPC3) cycles of normal and OGD conditions, respectively. The changes in the SH-SY5Y cells were then evaluated using an inverted microscope, cell counting, Hoechst staining, flow cytometry, and Western blot analysis. Results: IPC ameliorated the morphology of the SH-SY5Y cells, increased the survival rate (P < 0.05) and the activity of superoxide dismutase activity (P < 0.05), and decreased the apoptosis rate and the expression of Bcl-2 associated protein X (Bax). The differences were significant between the control and the ischemia/reperfusion groups, and the ischemia/reperfusion group and the IPostC2 and 3 groups. 2 to 3 cycles of alternative normal and OGD cultures of 12 h-OGD treated SH-SY5Y cells could mimic the protection of IPC. The protective mechanisms of IPC in the cell models are likely achieved via anti-apoptotic and anti-oxidant mechanisms. Conclusions: This work demonstrates that an in vitro model of neuroblastoma cells can mimic the neuroprotection mechanisms observed in vivo and would facilitate the mechanistic research on IPC.