Electroacupuncture Pretreatment Alleviates Cerebral Ischemia-reperfusion Injury by Down-regulating Mir-155-5p

Background: Increasing evidence shows that electroacupuncture pretreatment (EP) plays a crucial role in cerebral ischemia-reperfusion (I/R) injury, and cerebral I/R injury is the most serious complication of ischemic stroke treatment. The role of miR-155-5p in cerebral I/R injury has been studied, but the regulation of EP on miR-155-5p has not been reported. Methods: The middle cerebral artery occlusion (MCAO) mice were used to investigate the role of EP in cerebral I/R injury. Longa and modified neurological severity scores (mNSS) were used to evaluate neurological impairment. HE staining and TUNEL staining were used to evaluate brain injury. The expressions of miR-155-5p, Yin Yang 1 (YY1) and p53 were detected by qRT-PCR. The expressions of related proteins were detected by western blot. The binding of YY1 to miR- 155-5p was verified by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay. Mice brain microvascular endothelial cells (BMECs) were isolated and cultured for in vitro experiments. Oxygen-glucose deprivation/reoxygenation (OGD/R) was used to verify the role of YY1, p53 and miR-155-5p in cerebral I/R injury in vitro. Results: MCAO modeling induced brain injury, apoptosis, and increased levels of miR-155-5p, YY1, and p53. EP markedly alleviated brain injury and reduced levels of miR-155-5p, p53, and YY1. miR-155 agomir markedly increased the expression of miR-155-5p and p53. miR-155 antagomir decreased the levels of miR-155-5p and p53. Dual-luciferase reporter and ChIP assay verified that YY1 regulated miR-155-5p expression. YY1 shNRA greatly decreased miR-155-5p and p53. Inhibition of p53 decreased miR-155-5p expression. Both miR-155-5p inhibitor and YY1 shRNA promoted proliferation, inhibited apoptosis, and decreased levels of ICAM-1 and Eselectin of OGD/R-treated BMECs. Inhibition of p53 strengthened the effect of miR-155-5p inhibitor and YY1 shNRA on BMECs. Conclusion: Electroacupuncture pretreatment alleviates cerebral ischemia-reperfusion injury by regulating the YY1/p53/miR-155-5p axis.