Electroacupuncture Ameliorates Cerebral Ischemia-reperfusion Injury by Inhibiting Pyroptosis through the Sirtuin-1 Pathway

NOD-like receptor protein 3 (NLRP3)-mediated pyroptosis is pivotal in the pathological development of cerebral ischemia/reperfusion injury (CIRI). Although previous research has shown that electroacupuncture (EA) can alleviate CIRI through sirtuin-1 (SIRT1), the mechanism has not been well elucidated. Our study aimed to clarify whether the neuroprotective functions of EA are related to the reduction in NLRP3-mediated pyroptosis through the SIRT1 pathway. Rats received daily pretreatment with EA for 5 consecutive days before undergoing middle cerebral artery occlusion surgery. The Longa score was used to assess neurologic function. Infarct volume and morphological alterations were analyzed using 2,3,5-triphenyltetrazolium chloride and hematoxylin and eosin staining. In addition, neuronal pyroptosis was identified by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling/caspase-1 and neuronal nuclear antigen/caspase-1 immunofluorescence double staining. Levels of expression of pyroptosis markers were assessed by Western blotting and enzyme-linked immunosorbent assay. EA improved deficits in neurologic function and minimized cerebral infarct volume. Mechanistically, a number of neuronal pyroptotic cells and protein levels of NLRP3, apoptosis-associated speck-like protein containing a CARD, and gasdermin D in the cerebral cortex were markedly reduced by EA treatment, and conversely, SIRT1 levels were increased. Notably, the specific SIRT1 inhibitor, EX527, reversed the effects of EA. EA potentially exerts a neuroprotective effect against CIRI through the SIRT1 pathway in NLRP3-mediated pyroptosis.