[Effects of acupotomy intervention on regional pathological changes and expression of carti- lage-mechanics related proteins in rabbits with knee osteoarthritis].

Objective: To observe the effect of acupotomy (needle-knife) therapy on local pathological changes and cartilage-mechanics related protein expression in rabbits with knee osteoarthritis (KOA) so as to study its mechanisms underlying improving KOA.

Methods: Forty New Zealand rabbits were randomly divided into normal control group, model group, acupotomy group, and electroacupuncture (EA) group (n = 10 in each group). The KOA model was established by immobilization of the left knee-joint (modified Videman method) for 6 weeks. After modeling, acupotomy relaxing was applied to the lateral collateral ligament and patellar ligament of the left knee-joint, once a week for 3 times, and EA (2 Hz/100 Hz, 3 mA) was applied to the left "Yanglingquan" (GB 34), "Yinlingquan" (SP 9), "Neixiyan" (EX-LE 4) and "Waixiyan" (ST 35) for 20 min, 3 times a week for three weeks. The expression levels of Integrin β1, type II collagen (Col-II), matrix metalloproteinase (MMP)-3 and Aggrecan proteins of the cartilage tissue of the left femoral medial and external condyles were observed by Western blot. Pathological changes of the knee-joint by X-ray scanning and those of the femoral condyle tissue were evaluated by Mankin's scores under light microscope after H. E. staining.

Results: X-ray showed successful modeling, and pathological changes of the articular cartilage belonged to the early and moderate lesion of knee osteoarthritis. The Mankin's score was significantly higher in the model group than in the control group (P < 0.01) , and after the treatment, the Mankin's scores were significantly decreased in the acupotomy. group (P < 0.01), rather than in the EA group (P > 0.05). The results of Western blot showed that after modeling, the expression levels of Integrin β 1, Col-II and Aggrecan proteins of the femoral articular cartilage were considerably decreased (P < 0.01), while that of MMP-3 protein was significantly increased (P < 0.01). Compared with the model group, the decreased expression levels of Integrin β 1, Col-II and Aggrecan proteins in the acupotomy group and Integrin β 1 protein in the EA group were notably up-regulated (P < 0.01 , P < 0.05), and MMP-3 expression in the acupotomy group was significantly down-regulated (P < 0.01). No significant changes were found in the EA group in the expression levels of Col-II , Aggrecan and MMP-3 proteins compared with the model group (P > 0.05).

Conclusion: Acupotomy intervention can relieve KOA-induced injury of the knee-joint in KOA rats, which is associated with its actions in raising expression levels of Integrin β 1, Col-II and Aggrecan proteins and in lowering the expression of MMP-3 proteins in the articular cartilage, probably by adjusting the mechanics-related signal pathway of the articular chondrocytes.