Background & Aims
Knee osteoarthritis (KOA) is an age-related disease that causes pain and limited joint range of motion due to degeneration of articular cartilage, leading to a decline in quality of life [1][2]. Aggrecanase (ADAMTS5), which degrades aggrecan necessary for healthy articular cartilage, is involved in the development of KOA [3]. Electroacupuncture (EA) therapy is a treatment that applies a mild current at acupoints through acupuncture needles. EA has shown to have potential benefit for KOA; however, its effect on articular cartilage is still unclear [4][5]. In this study, we investigate the analgesic effects of EA on knee joint pain and the inhibitory effect of EA on the expression of ADAMTS5 in the synovium of the knee joint using KOA model rats [6].
Methods
Rats were divided into four groups: control group, sham surgery group, OA group, and EA treatment group for ST36 (Zusanli) and Ex-LE2 (Heiding) acupoints after OA induction (OA + EA) group. OA was induced by cutting the medial tibial meniscal ligament of the right knee of a rat and destabilizing the medial meniscus [6]. EA with parameters (1.5 mA, 2 Hz) was administered three times a week, for 30 minutes each time, for four weeks after surgery. The rotarod test was carried out before surgery and on days 28 after surgery to measure a loss of motor coordination [7]. In addition, to evaluate knee joint pain, the expression level of c-fos in the dorsal horn of the spinal cord was examined using immunofluorescence four weeks after the surgery. Moreover, histological assessment and western blot analysis were performed to investigate degenerative changes in articular cartilage and the expression of ADAMTS5 in synovium of the right knee joint at the same time.
Results
Rats in the OA group exhibited a marked decrease in the time spent on the rod on days 28 compared to the control group; however, the reduction was significantly inhibited in the OA + EA group. The number of c-fos-positive cells was significantly higher in the OA group in the dorsal horn of the spinal cord compared to the control group. However, this increase was significantly suppressed in the OA + EA group. Furthermore, the progression of articular cartilage degeneration and the increased expression of ADAMTS5 in the synovium were observed in the OA group. These changes were significantly suppressed in the OA + EA group.
Conclusions
These results suggest that EA attenuates the knee joint pain induced by KOA, and inhibits the progression of articular cartilage degeneration by suppressing the secretion of ADAMTS5 in the joint synovium.
References
[1] Kolasinski SL, et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis Rheumatol. 2020; 72:220-33.
[2] Liew JW, et al; OARSI Early Osteoarthritis Classification Criteria Task Force. A scoping review of how early-stage knee osteoarthritis has been defined. Osteoarthritis Cartilage. 2023; 31:1234-41.
[3] Zhao SS, et al. ADAMTS5 as a therapeutic target for osteoarthritis: Mendelian randomisation study. Ann Rheum Dis. 2022; 81:903-4.
[4] [No authors listed] Evidence review for the clinical and cost-effectiveness of acupuncture for people with osteoarthritis: Osteoarthritis in over 16s: diagnosis and management: Evidence review F. London: National Institute for Health and Care Excellence (NICE); 2022 Oct.
[5] Ma Y, et al. A rat model of knee osteoarthritis suitable for electroacupuncture study. Exp Anim. 2018; 67:271-80.
[6] Glasson SS, et al. The surgical destabilization of the medial meniscus (DMM) model of osteoarthritis in the 129/SvEv mouse. Osteoarthritis Cartilage. 2007; 15:1061-9.
[7] Oike J, et al. Preventive Effect of the Japanese Traditional Herbal Medicine Boiogito on Posttraumatic Osteoarthritis in Rats. Medicines (Basel). 2020; 7:74.
Presenting Author
Hideshi Ikemoto
Poster Authors
Hideshi Ikemoto
PhD
Showa University Graduate School of Medicine
Lead Author
Oyunchimeg Chuluunbat
Showa university
Lead Author
Takayuki Okumo
Ph.D.
Showa university
Lead Author
Naoki Adachi
Ph.D.
Showa university
Lead Author
Tadashi Hisamitsu
Ph.D.
Showa University, Tokyo, Japan
Lead Author
Masataka Sunsgawa
Showa University, Japan
Lead Author
Topics
- Treatment/Management: Complementary and Alternative therapies