Electroacupuncture Protects Against Cerebral Ischemia-Reperfusion Injury: Reducing Inflammatory Response and Cell Pyroptosis by Inhibiting P2X7/NLRP3/GSDMD Pathway

Abstract

Purpose To investigate the mechanism underlying the effects of Tongdu Tiaoshen electroacupuncture in the treatment of cerebral ischemia-reperfusion (I/R) injury. Methods Sixty adult male Sprague-Dawley (SD) rats were randomly allocated to five groups (n=12): Sham, I/R, electroacupuncture (EA), BBG (P2X7R inhibitor), and MCC950 (NLRP3 inhibitor). The EA group received acupuncture at Shenting (GV24), Baihui (GV20), and Dazhui (GV14) points with a stimulation frequency of 2/5 Hz, intensity of 2 mA, and a duration of 40 min. Neurologic deficit scoring was then performed, and cerebral infarction volume was determined using triphenyl tetrazolium chloride (TTC) staining. Morphological changes in neurons in cortical areas were observed using an electron microscope, interleukin-18 (IL-18) and interleukin-1β (IL-1β) levels were assessed via the enzyme-linked immunosorbent assay (ELISA). Moreover, the expression of P2X7R/NLRP3/GSDMD pathway-related proteins and mRNAs was quantified by immunofluorescence staining, Western blot assay, and real-time fluorescence quantitative (RT-PCR) analysis. Results Electroacupuncture improved neurologic deficit scores, cerebral infarct size, and cell pyroptosis, and reduced IL-1β and IL-18 levels. Furthermore, electroacupuncture and inhibitor treatment significantly downregulated the expression of P2X7R, ASC, Caspase-1, NLRP3, and GSDMD involved in the P2X7/NLRP3/GSDMD signaling pathway. Conclusion Tongdu Tiaoshen electroacupuncture may exert cerebral protection by inhibiting neuroinflammation through the P2X7/NLRP3/GSDMD pathway and reducing cellular pyroptosis.