Effects of hyperbaric oxygen on the blood-brain barrier via the SIRT1/FoxO1 signaling pathway after cerebral ischemia and reperfusion / 中华物理医学与康复杂志

ABSTRACT

Objective:To explore the effect of hyperbaric oxygen (HBO) on the blood-brain barrier via the silent information regulator 1 (SIRT1)/Forkhead box O1(FoxO1) signaling pathway after cerebral ischemia and reperfusion using a rat model.Methods:Forty Wistar rats were randomly assigned into sham, cerebral ischemia-reperfusion (CIR), CIR+ HBO and CIR+ HBO+ EX527 groups, each of 10. The cerebral ischemia-reperfusion model was established in all groups except the sham group by right middle cerebral artery occlusion using the modified thread-occlusion method. The sham group was not ligated. Both the CIR+ HBO and CIR+ HBO+ EX527 groups were given HBO 1, 9, 21, 45 and 69 hours after the reperfusion. The CIR+ HBO+ EX527 group was additionally injected with 5mg/kg of EX527(a SIRT1inhibitor) peritoneally 4, 12, 24, 48 and 72 hours after the reperfusion. Then 2% Evens blue (EB) was injected into the tail vein an hour before the rats were sacrificed. The content of EB and the expression of SIRT1, FoxO1, ZO-1, Occludin, Claudin-5 mRNA and their proteins were determined using spectrophotometry, reverse transcription-polymerase chain reactions and Western blotting.Results:The average EB content of the hippocampal brain tissue from the CIR, CIR+ HBO and CIR+ HBO+ EX527 rats was significantly greater than the Sham group′s average 72h after reperfusion. The average expression of SIRT1, FoxO1, ZO-1, Occludin and Claudin-5 mRNA and their proteins was significantly lower, with the CIR + HBO + EX 527 group′s average significantly lower than that of the CIR+ HBO group.Conclusions:HBO can increase the expression of tight junction protein via the SIRT1/FoxO1 pathway. It helps to protect the blood-brain barrier in CIR injury situations.