Journal of Pain Research (Jan 2022)
Imaging Study on Acupuncture Inhibiting Inflammation and Bone Destruction in Knee Osteoarthritis Induced by Monosodium Iodoacetate in Rat Model
Abstract
Qian Tan,1,* Zhengkun Cai,2,* Jia Li,3 Jing Li,1 Hongchun Xiang,1 Bocun Li,1 Guowei Cai1 1Department of Acupuncture, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China; 2Department of Public Administration, Huazhong University of Science and Technology, Wuhan, People’s Republic of China; 3College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, People’s Republic of China*These authors contributed equally to this workCorrespondence: Guowei CaiDepartment of Acupuncture, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of ChinaEmail [email protected]: We aim to explore whether acupuncture inhibits inflammation and bone destruction in rat model monosodium iodoacetate (MIA)-induced knee osteoarthritis (KOA) by 18F-fluorodeoxyglucose (18F-FDG) small-animal positron emission tomography (PET) and micro-computed tomography (CT) imaging.Methods: KOA was induced in rats by intra-articular injection MIA (2 mg/50 μL) through the right knee of the rats. Forty male Sprague Dawley rats weighing 280 to 340 g (12 weeks old) were randomly divided into four groups including Control group, KOA group, KOA plus manual acupuncture group (KOA+MA), KOA plus sham acupuncture group (KOA+SA). The acupuncture treatment lasted for three weeks (one-day rest after six days of treatment). Paw withdrawal threshold test and open-field test were used to assess mechanical allodynia and locomotor activity respectively for once a week. Hematoxylin and eosin (H&E) staining was used to assess the damage of the cartilage, synovium and infrapatellar fat pad (IFP). 18F-FDG PET was performed to quantify joint inflammation. The influence on the subchondral bone in these rats was confirmed by micro-CT.Results: Mechanical hyperalgesia, joint inflammation, and obvious bone destruction were observed in the KOA group. H&E staining of the knee joint found that manual acupuncture played a protective effect in cartilage, synovium and IFP destruction. However, compared with KOA group, the results in sham acupuncture had no significant difference. After manual acupuncture treatment in KOA rats, inflammation was significantly suppressed shown by 18F-FDG PET imaging. Micro-CT analysis of the knee joint revealed that manual acupuncture protected bone by inhibiting osteophyte development and subchondral bone remodeling.Conclusion: The results of 18F-FDG PET and micro-CT showed that manual acupuncture inhibited inflammation and bone destruction, which provides reliable evidence for the effectiveness of acupuncture in hindering development of KOA, and provides reliable evidence for clinical application of acupuncture.Keywords: osteoarthritis, acupuncture, PET, micro-CT, inflammation, bone destruction
