Electroacupuncture reduces microglial pyroptosis via P2X7R/NLRP3 axis in the rat model of asphyxial cardiac arrest and cardiopulmonary resuscitation

Abstract

Asphyxial cardiac arrest and cardiopulmonary resuscitation (ACA/CPR) can severely damage the brain, but electroacupuncture may help reduce this damage through its anti-inflammatory effects. This study explored whether EA could mitigate microglial pyroptosis via the P2X7R/NLRP3 pathway in a rat ACA/CPR model, given that P2X7R activates the NLRP3 inflammasome, leading to pyroptosis and the release of inflammatory factors. Rats underwent an 8-minute ACA/CPR model, with EA stimulation at Baihui (GV 20), Shuigou (DU 26), and bilateral Neiguan (PC 6) every 12 h for three days. P2X7R was modulated using the inhibitor AZ10606120 and the agonist BzATP. Protein expression changes were analyzed using western blotting, ELISA, flow cytometry, and immunofluorescence. ACA/CPR outcomes assessed included survival rate, neurological deficits, brain injury serum markers, and hippocampal ATP levels. The data indicated that microglia activation and co-localization with P2X7R/GSDMD occurred in the hippocampus of the ACA/CPR model, while EA reduced pyroptosis and P2X7R expression 24 h after the restoration of spontaneous circulation (ROSC). In the primary microglial oxygen and glucose deprivation-reoxygenation (OGD/R) model, P2X7R expression increased and then gradually decreased as reoxygenation time progressed. P2X7R and GSDMD levels were high 6 h post-reoxygenation, but AZ10606120 reduced their expression. BzATP counteracted EA's suppression of P2X7R, NLRP3, caspase-1, cleaved caspase-1, GSDMD-FL, and GSDMD-N. Comparable assessments were conducted within the ACA/CPR + AZ10606120 and ACA/CPR cohorts. Consequently, it was deduced that EA exerts a neuroprotective effect following ACA/CPR by modulating P2X7R expression and suppressing microglial pyroptosis.

Keywords: Asphyxial cardiac arrest and cardiopulmonary resuscitation; Electroacupuncture; Microglia; NLRP3; P2X7R; Pyroptosis.