Objective: To observe the effect of moxibustion on AMP-activated protein kinase (AMPK)/UNC-51-like kinase 1 (ULK1) signaling pathway in the synovial tissue of toes in rheumatoid arthritis rats, so as to explore the mechanism of mo-xibustion in the treatment of rheumatoid arthritis (RA).
Methods: A total of 45 SD rats were randomly divided into blank, model， moxibustion, methotrexate and rapamycin groups, with 9 rats in each group. RA rat model was established by injection of Freund's complete adjuvant. Moxibustion was applied to "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, once a day for 3 weeks. Methotrexate group was given methotrexate (0.35 mg/kg) by gavage, twice a week for 3 weeks. Rapamycin group was intraperitoneally injected with rapamycin (1 mg/kg)，once every other day for 3 weeks. The toe volume of the left hind limb of rats was measured by the toe volume measuring instrument. The content of AMP in toe synovium was detected by ELISA. The expression of AMPK and VPS34 protein in toe synovium was detected by Western blot.The expression of ULK1 and Atg13 mRNA in toe synovium was detected by RT-PCR.
Results: Compared with the blank group, the volume of toe in the model group was increased (P<0.01)，while the content of AMP, the expression of AMPK and VPS34 proteins, the expression of ULK1 and Atg13 mRNAs were significantly decreased(P<0.01).Compared with the model group, the volume of toe in the moxibustion，methotre-xate and rapamycin groups was decreased (P<0.05); the content of AMP, the expression of AMPK and VPS34 proteins, the expression of ULK1 and Atg13 mRNAs were significantly increased(P<0.05) in the moxibustion group; the content of AMP, the expression of VPS34 protein, the expression of Atg13 mRNA were significantly increased(P<0.05) in the methotrexate group; the expression of AMPK and VPS34 proteins, the expression of ULK1 and Atg13 mRNAs were significantly increased (P<0.05, P<0.01) in the rapamycin group. Compared with the moxibustion group, the expression of AMPK protein in the methotrexate group and the content of AMP in the rapamycin group were significantly decreased (P<0.05).
Conclusion: Moxibustion can improve joint swelling in RA rats, and the mechanism may be related to promoting the activity of AMPK/ULK1 signaling pathway.
目的：观察艾灸对类风湿关节炎(RA)大鼠足趾关节滑膜组织中环磷酸腺苷(AMP)依赖的腺苷酸活化蛋白激酶(AMPK)/UNC-51样激酶1(ULK1)信号通路的影响，探索艾灸治疗RA的作用机制。方法：SD大鼠按照随机数字表法分为空白组、模型组、艾灸组、甲氨蝶呤组、雷帕霉素组，每组9只。采用弗氏完全佐剂注射法制备RA大鼠模型。艾灸组艾灸“足三里”“关元”，20 min/次，每日1次。甲氨蝶呤组予甲氨蝶呤灌胃(0.35 mg/kg)，每周2次。雷帕霉素组予腹腔内注射雷帕霉素(1 mg/kg)，隔日1次。各组均干预3周。足趾容积测量仪检测大鼠左后肢足趾容积;ELISA法检测大鼠足趾关节滑膜组织中AMP含量；Western blot法检测大鼠足趾关节滑膜组织中AMPK、液泡分选蛋白34（VPS34）蛋白表达量；real-time PCR法检测足趾关节滑膜组织中Atg13、ULK1 mRNA的表达水平。结果：与空白组比较，模型组足趾容积增大(P<0.01)，足趾关节滑膜组织AMP含量、AMPK和VPS34蛋白表达量、ULK1和Atg13 mRNA表达水平显著降低(P<0.01)。与模型组比较，艾灸组、甲氨蝶呤组、雷帕霉素组足趾容积减小(P<0.05)；艾灸组足趾关节滑膜组织AMP含量、AMPK和VPS34蛋白表达量、ULK1和Atg13 mRNA表达水平明显升高(P<0.05)；甲氨蝶呤组AMP含量、VPS34蛋白表达量、Atg13 mRNA表达水平明显升高(P<0.05)；雷帕霉素组AMPK和VPS34蛋白表达量、ULK1和Atg13 mRNA表达水平明显升高(P<0.05，P<0.01)。与艾灸组比较，甲氨蝶呤组足趾关节滑膜组织AMPK蛋白表达量明显降低(P<0.05)；雷帕霉素组AMP含量明显降低(P<0.05)。结论：艾灸能改善RA大鼠关节肿胀，其作用机制可能与激活AMPK/ULK1信号通路有关。.
Keywords: AMPK/ULK1 signaling pathway; Moxibustion; Rheumatoid arthritis; Synovial cells of toes.