Effect of acupotomy on chondrocyte proliferation and expression of CyclinD1, CDK4 and CDK6 in rabbits with knee osteoarthritis

ObjectiveThe aim of this study was to investigate the mechanism of acupotomology (Apo) in the prevention of articular cartilage destruction via the promotion of chondrocyte proliferation and chondrocyte expression of cell cycle regulators, CyclinD1, CDK4 and CDK6 in a rabbit knee osteoarthritis (KOA) model.MethodsTwenty-eight rabbits were randomly divided into a control group, an OA (osteoarthritis) model group, an Apo (acupotomology) group and EA (electro-acupuncture) group (n = 7). Improved Videman's method was used to induce a rabbit model of KOA over 6 weeks. One week later, acupotomy and electro-acupuncture therapy was applied to animals in the respective groups and treatment lasted 4 weeks. Following these treatments, quantitative real-time PCR, immunohistochemical staining and western blotting were performed to assess the mRNA and protein levels of cell cycle regulators CyclinD1 (Cell cycle protein D1), CDK4 (Cyclin-dependent kinase 4) and CDK6 (Cyclin-dependent kinase 6). Ethology measures and knee morphology were also compared among groups.ResultsThe Lequesne MG index score of morphology was increased (P < .01), and the passive range of motion (PROM) and the mRNA and protein levels of CyclinD1, CDK4, and CDK6 were significantly decreased (P < .01) in the OA model compared with the control group. The Lequesne MG index score and the morphology score were decreased in the Apo and EA group compared with the OA model group (P < .05 or P < .01), while the mRNA levels of CyclinD1, CDK4, and CDK6, and the protein levels of CDK4 were increased in the Apo and EA groups compared with the OA model group (P < .05 or P < .01). The PROM, and the protein levels of CyclinD1 and CDK6 were increased (P < .05) in the Apo group compared with the OA model group, while the PROM and the protein levels of CyclinD1 and CDK6 in the EA group were not significantly different (P > .05). Compared with the EA group, the morphology score was decreased in Apo group (P < .05).ConclusionsThe mRNA levels of CyclinD1 and CDK4, and the protein level of CDK4 in chondrocytes are regulate by both Apo and EA. Apo is more effective than EA in regulating the protein levels of CyclinD1 and CDK6. According to the observed changes in morphology and cytokine levels, acupotomy can promote chondrocyte proliferation and can alleviate the destruction of articular cartilage in a model of KOA.