Electroacupuncture protects against cerebral ischemia-reperfusion injury via regulating P2X7R expression

Clinically, ischemic stroke is a serious disease hard to cure, therefore it is of great importance to slow down the depletion of ATP to enhance the tolerance of ischemic tissue through aggressive preconditioning. Electroacupuncture (EA) preconditioning has been reported to produce a tolerance for cerebral ischemia, with the underlying mechanism remaining unclear. Given that the P2X7 receptor (P2X7R) mediates the stimulation of microglial cells and is involved in the developmental process of cerebrum ischemia-reperfusion (I/R) damage, we hypothesized that the protective effect of Electroacupuncture preconditioning might be associated with the downregulated P2X7R. In this study, 2 '(3')-O-(4-benzoyl) adenosine triphosphate (BzATP) was utilized as a P2X7R agonist in rats with cerebral ischemia-reperfusion injury (MCAO), from which we found that EA preconditioning ameliorated neurologic scoring, decreased infarction volume, and necrotic neurons, and decreased the release of cytokines, while BzATP exacerbated cerebrum I/R damage and inflammation events compared with the favorable efficacy of EA. In addition, BzATP reversed the positive effects mediated by EA, which was consistent with increased expression of P2X7R. These findings suggest that EA induces cerebral ischemic tolerance to ischemia-reperfusion(I/R) damage by suppressing the expression of P2X7R and the release of inflammatory factors.