[Effect of different acupuncture and moxibustion methods on muscle inflammation and muscle atrophy related proteins in the gastrocnemius of rats with knee osteoarthritis].

Abstract

Objectives: To compare the effects of filiform acupuncture, electroacupuncture (EA) and moxibustion on gastrocnemius inflammation and muscle atrophy related proteins in rats with knee osteoarthritis (KOA).

Methods: A total of 40 Wistar rats were randomly divided into blank control, model, filiform acupuncture, EA and moxibustion groups, with 8 rats in each group. The KOA model was established by intra-articular injection of sodium iodate into the right knee joint in the model group and treatment groups (filiform acupuncture, EA and moxibustion groups). Treatment groups received filiform acupuncture, EA and moxibustion on the right "Futu" (ST32) and "Housanli"(ST36) for 15 min each time, once every other day, for 4 weeks. The diameter of the right knee joint of rats in each group were measured and the structure of knee joint was observed by X-ray before modeling, after modeling, and after treatment. After treatment, the Pinnate angle, muscle thickness and cross-sectional area of right rectus femoris were measured by ultrasound, the ultrastructure of right gastrocnemius muscle was observed by transmission electron microscope, the contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-10 in right gastrocnemius muscle were detected by enzyme-linked immunosorbent assay (ELISA), and the expression levels of sirtuin1(SIRT1), muscle-specific ringfinger protein 1(MuRF1), nuclear factor erythroid 2-related factor 2(NRF2) and recombinant transcription factor A(TFAM) in right gastrocnemius muscle were detected by Western blot in each group.

Results: Compared with the blank control group, the diameter of the right knee joint increased (P<0.01), the knee joint space of the model group was obviously narrowed, accompanied by osteophyte formation at the joint edge and subchondral bone reactive hyperplasia, the Pinnate angle, muscle thickness and cross-sectional area of rectus femoris decreased (P<0.01), the mitochondria of gastrocnemius muscle cells swelled, the muscle fibers arranged disorderly, the sarcomere structures were destroyed, the Z-line fractures were discontinuous, the contents of TNF-α and IL-6 in gastrocnemius muscle were increased (P<0.01), and IL-10 was decreased (P<0.01), the protein expression of MuRF1 was increased (P<0.01), whereas the expressions of SIRT1, NRF2, and TFAM proteins decreased (P<0.01) in the model group. Compared with the model group, all these indicators were reversed in the treatment groups (P<0.01, P<0.05). In the moxibustion group, the muscle thickness of rectus femoris was higher (P<0.01) than those in the filiform acupuncture and EA groups, the Pinnate angle was higher (P<0.01) than that in the EA group, and the cross-sectional area was lower (P<0.05) than that in the EA group. The content of IL-10 in gastrocnemius muscle in the EA group was higher (P<0.01) than those in the moxibustion and filiform acupuncture groups. The expressions of MuRF1 protein in the gastrocnemius muscle were lower (P<0.01) in the EA and moxibustion groups compared to the filiform acupuncture group.

Conclusions: Filiform acupuncture, EA and moxibustion can improve knee joint swelling, ameliorate muscle ultrastructure and muscle fiber, regulate inflammatory cytokine level, improve KOA by modulating muscle atrophy related proteins SIRT1/MuRF1 and NRF2/TFAM. There was no significant difference in the efficacy among the three methods of acupuncture and moxibustion.