Journal of Pain Research (Aug 2023)
Electroacupuncture Exerts Chondroprotective Effect in Knee Osteoarthritis of Rabbits Through the Mitophagy Pathway
Abstract
Longfei Xing,1,* Xilin Chen,2,3,* Changqing Guo,1 Wenting Zhu,4 Tingyao Hu,1 Weiwei Ma,1 Mei Du,1 Yue Xu,1 Changqing Guo5 1School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, People’s of Republic of China; 2Department of Acupuncture and Rehabilitation, The Fifth College of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine, Guangzhou, People’s Republic of China; 3Department of Acupuncture and Rehabilitation, Guangdong Second Hospital of Traditional Chinese Medicine, Guangzhou, People’s Republic of China; 4The Third Affiliated Hospital of Beijing University of Chinese Medicine, Beijing, 100029, People’s Republic of China; 5Department of Medical Technology, Shijiazhuang Medical College, Shijiazhuang, Hebei Province, People’s of Republic of China*These authors contributed equally to this workCorrespondence: Changqing Guo, Shijiazhuang Medical College, Shijiazhuang, Hebei Province, 050599, People’s of Republic of China, Tel +86-13081033381, Fax +86-82517626, Email [email protected]: Mitochondrial dysfunction of chondrocytes has become an area of focus in Knee Osteoarthritis (KOA) in recent years. Activation of mitophagy could promote the survival of chondrocytes and alleviate cartilage degeneration. The aim of this study was to explore whether mitophagy was involved in the cartilage protection of KOA rabbits after electroacupuncture (EA) intervention.Methods: The rabbits were divided into 3 groups, Control group, KOA group, EA group, with 6 rabbits in each group. KOA model rabbits were established by modified Videman’s extended immobilization method for 6 weeks and randomly divided into KOA group and EA group. The rabbits in EA group were treated every other day for 3 weeks. The degree of cartilage degeneration was detected by Safranine O-Fast Green staining and immunofluorescence. The morphological changes of chondrocytes mitochondria were detected by transmission electron microscope. ATP concentration in cartilage was measured by ATP Assay Kit. The changes of Pink1-Parkin signal pathway were detected by immunofluorescence, Western blot, and Real-time PCR.Results: The morphology showed that EA could reduce the degeneration of KOA cartilage and increase the distribution of collagen II. We also found that EA could activate mitophagy in KOA rabbit chondrocytes to remove damaged mitochondria and restore mitochondrial homeostasis, which was manifested as increasing the expression of LC3 II/I, promoting the colocalization of TOM20 and LC3B, reducing the accumulation of mitochondrial markers outer mitochondrial membrane 20 (TOM20) and inner mitochondrial membrane 23 (TIM23), and increasing ATP production in chondrocytes. This regulation might be achieved by upregulating the Pink1-Parkin signal pathway.Conclusion: EA may play a role in protecting KOA cartilage by activating mitophagy mediated through Pink1-Parkin pathway.Keywords: osteoarthritis, electroacupuncture, mitophagy, mitochondria, Pink1-Parkin
