Electroacupuncture combined with exercise training promotes functional recovery of spinal cord injury by regulating AIM2 inflammasome-mediated cell pyroptosis

ZHANG Lili; GAO Mingming; WU Maojuan

doi:10.3969/j.issn.1002-7386.2025.05.006

Abstract：Objective To explore the mechanism of electroacupuncture(EA)combined with treadmill exercise training in promoting functional recovery of spinal cord injury(SCI)by regulating absent in melanoma 2(AIM2)inflammasome-mediated cell pyroptosis.Methods Seventy Sprague-Dawley(SD)rats were selected as the research subjects.Fifty rats were randomly divided into 5 groups with 10 rats per group:sham operation group(Sham,n=10),SCI group(SCI,n=10),EA group(EA,n=10),treadmill training group(Treadmill,n=10),and EA combined with treadmill training group(EA+Treadmill,n=10).The experimental period was 8 weeks,and the recovery of SCI was analyzed using the Basso,Beattie and Bresnahan(BBB)scale.The hematoxylin and eosin(H&E)staining was used to analyze the pathological morphology of the spinal cord in each group of rats.Enzyme-linked immunosorbent assay(ELISA)was conducted to detect inflammatory factors(interleukin-1 beta[IL-1β],tumor necrosis factor-alpha[TNF-α],interleukin-6[IL-6],interleukin-18[IL-18])levels in spinal cord tissue of rats in each group.Western blot was performed to detect protein levels of AIM2,and pyroptosis-associated proteins pro-caspase-1,pro-IL-1β and GSDMD.In addition,20 rats were randomly divided into Ac-YVADcmk(AIM2 inhibitor,n=10)group,and EA+Treadmill+Ac-YVADcmk(n=10)group.Inflammatory factors(IL-1β,TNF-α,IL-6,IL-18)were detected by ELISA,and protein levels of AIM2,pro-caspase-1,pro-IL-1β and GSDMD in spinal cord tissue were compared by Western blot among the EA+Treadmill,Ac-YVADcmk and EA+Treadmill+Ac-YVADcmk groups.Results Before treatment,the BBB scores of SCI rats were significantly lower than the Sham group(P＜0.05),which were significantly elevated in SCI rats after treatment(P＜0.05).Compared with the SCI group,the BBB scores of rats in the EA and Treadmill groups were significantly improved(P＜0.05).Compared with EA group and Treadmill group rats,the BBB score of EA+Treadmill group rats further increased(P＜0.05).SCI rats showed pyknosis,nuclear lysis,cell necrosis,increased infiltration of vacuolar and inflammatory cells,and significantly improved Markin score(P＜0.05).Both EA and treadmill exercise training significantly improved the pathological morphology of spinal cord tissue in SCI rats,reduced the Markin score,and the outcome was more pronounced by their combination(P＜0.05).Compared with the Sham group,SCI rats had significantly higher level of inflammatory factors(IL-1β,TNF-α,IL-6,IL-18),and protein levels of AIM2,pro-caspase-1,pro-IL-1β and GSDMD(P＜0.05).Compared with the SCI group,rats in the EA group and the Treadmill group showed significantly lower levels of inflammatory factors(IL-1β,TNF-α,IL-6,IL-18),and protein levels of AIM2,pro-caspase-1,pro-IL-1β and GSDMD(P＜0.05).The combination of EA and Treadmill showed the lowest levels of inflammatory factors(IL-1β,TNF-α,IL-6,IL-18),and protein levels of AIM2,pro-caspase-1,pro-IL-1β and GSDMD(P＜0.05).Compared with the SCI group,rats in the EA+Treadmill group and Ac-YVADcmk group showed significantly lower IL-18,AIM2,pro-caspase-1,pro-IL-1β and GSDMD(P＜0.05).The combination of EA,treadmill exercise and Ac-YVADcmk resulted in the lowest levels of IL-18,AIM2,pro-caspase-1,pro-IL-1β and GSDMD(P＜0.05).Conclusion The combination of EA and treadmill exercise training mediates cell apoptosis and inflammatory response in SCI rats by inhibiting the activation of AIM2 inflammasome,ultimately promoting SCI recovery and body motor performance.The combination of the two shows the best effect and is worthy of further clinical research.