To explore the action mechanism of electroacupuncture (EA) for knee osteoarthritis (KOA) based on Wnt/beta-catenin (Wnt/β-catenin) signaling pathway.
Ten rats were randomly selected into a sham-operation group among 50 male 2-month-old SD rats, and the KOA model was established in the remaining 40 rats by modified Hulth method. Four weeks after the model establishment, the rats were randomly divided into a model group, an experimental A group, an experimental B group and an experimental C group, 10 rats in each group. The rats in the sham-operation group and model group did not receive any intervention. The rats in the experimental A group were treated with EA at "Neixiyan" (EX-LE 4) and "Dubi"(ST 35) for 15 min. The rats in the experimental B group were treated with EA at "Neixiyan" (EX-LE 4) and "Dubi"(ST 35) for 30 min. The rats in the experimental C group were treated with EA at non-acupoint for 15 min. EA intervention was given once a day, five times a week, and totally 12-week treatment was given. After 12 weeks, the knee cartilage tissues were stained and the morphological changes were observed under light microscopy; the severity of cartilage degeneration was evaluated by modified Mankin's score; the content of interleukin-1β (IL-1β) in synovium tissues was detected by ELISA method; the content of Wnt-4, β-catenin and matrix metalloprotein-13 (MMP-13) in cartilage tissues was detected by Western blot method.
Compared with the sham-operation group, in the model group the morphology and structure of cartilage were disordered, the number of cells was significantly reduced, the matrix was decontaminated and tidal line was incomplete; the Mankin's score was significantly increased (
EA at "Neixiyan" (EX-LE 4) and "Dubi"(ST 35) may reduce the expression of MMP-13 and the production of inflammatory factor IL-1β through Wnt/β-catenin signaling pathway, thus inhibit the degradation of cartilage matrix and the apoptosis of chondrocyte, and improve the morphology and structure of cartilage.