[Electroacupuncture improves motor function of rats with osteoarthritis by alleviating joint inflammation through the Wnt-7B/β-catenin signaling pathway].

Objective: To investigate the effect of electroacupuncture on osteoarthritis in rats and explore the possible mechanism.
Methods: Thirty SD rats were randomly divided into osteoarthritis model group, electro-acupuncture group and control group ( n =10), and in the former two groups, early osteoarthritis was induced using a modified DMM surgical modeling method. After successful modeling, the rats in the electro-acupuncture group were treated with electro-acupuncture at bilateral "Housanli" and "Anterior knee point". Behavioral tests of the rats were performed and scored using the LequesneMG scale. Subchondral bone degeneration was observed in each group, and serum levels of IL-1β, ADAMTS-7, MMP-3 and COMP were measured using ELISA. The mRNA and protein expressions of IL-1β, Wnt-7B, β-catenin, ADAMTS-7, and MMP-3 in the cartilage tissue of the knee joints were detected using RT-PCR and Western blotting.
Results: In behavioral tests, the rats in the model and electroacupuncture groups had significantly higher LequesneMG scores after modeling than those in the control group ( P < 0.05). After 20 days of treatment, LequesneMG scores were significantly lowered in rats in the electroacupuncture as compared with the model rats ( P < 0.05). Imaging examination revealed obvious subchondral bone damage in both the electroacupuncture group and the model group, but the damages were significantly milder with former group. Compared with the model rats, the rats receiving electroacupuncture had significantly lower serum levels of IL-1β, ADAMTS-7, MMP-3 and COMP ( P < 0.05) with also lower expressions of IL-1β, Wnt-7B, β-catenin, ADAMTS-7 and MMP-3 in the cartilage tissues at both the mRNA and protein levels ( P < 0.05).
Conclusion: Electroacupuncture can alleviate joint pain and improve subchondral bone damage in rats with osteoarthritis by reducing IL-1β levels in the joint cartilage tissue and serum to alleviate joint inflammation and by reducing such cytokines as ADAMTS-7 and MMP-3 via regulating the Wnt-7B/β-catenin signaling pathway.