[Acupotomy relieves pain and improves motor function by regulating autophagy and apoptosis of cartilage in rabbits with knee osteoarthritis apoptosis].

OBJECTIVE

To observe the effect of acupotomy on the expression of Beclin-1, Bcl-2 and Caspase-3 in the cartilage tissue in rabbits with knee osteoarthritis (KOA), so as to explore its mechanism underling improvement of KOA.

METHODS

Twenty-four healthy male New Zealand rabbits were randomly and equally divided into blank control, model and acupotomy groups, with 8 rabbits in each group. By using the modified Videman's methods, the KOA model was established by left hind limb immobilization with a plaster cast for 6 weeks. The severity of KOA (knee pain, swelling and motor function) was assessed using Lequesne score, and the rabbits with a score below 4 were excluded. The acupotomy was applied to "Hedingci" (the attachment of the quadriceps tendon to the patella at the upper edge), "Binneixia" (the medial patellar supporting band attachment of medial inferior patellar margin), "Binwaixia" (the lateral patellar supporting band attachment of the lower lateral patellar margin), "Chengfeijian" (the lateral collateral ligament of the knee passes over the lateral joint space), "Weiyangci" (the medial margin of biceps femoris at the lateral end of popliteus), "Yinlingci" (the medial tibial attachment of anserinus tendon) on the left hind limb once a week for 4 weeks. One week after the last intervention, the left knee joint dysfunction severity(pain, maximum walking distance, and some activities of daily living) was evaluated by using modified Lequesne score. Histopathological changes of the cartilage were observed under light microscope after H.E. staining. The apoptosis of chondrocytes was observed after terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick-end labeling (TUNEL) staining. The autophagolysosomes of chondrocytes were observed using transmission electron microscopy. The expression levels of Beclin-1, Bcl-2 and Caspase-3 (related factors of autophagy and apoptosis) were detected using Real-time PCR and Western blot separately.

RESULTS

In comparison with the blank control group, the Lequesne score, apoptosis rate, expression levels of Caspase-3 mRNA and protein were significantly increased (<0.001), and the number of autophagolysosomes, expression levels of Beclin-1 and Bcl-2 mRNAs and proteins considerably decreased (<0.001) in the model group. Relevant to the model group, the acupotomy group had an obvious decrease in Lequesne score, rate of apoptosis, and expression levels of Caspase-3 mRNA and protein (<0.001) and an apparent increase in the number of autophagolysosomes and expression levels of Beclin-1 and Bcl-2 mRNAs and proteins (<0.001). Findings of H.E. staining showed severe damaged cartilage surface, with a large number of exfoliation defects, few chondrocytes on the surface and disordered arrangement of transitional cells in the model group, which was relatively milder in the acupotomy group.

CONCLUSION

Acupotomy can mitigate knee-joint pain and improve functional activity in KOA rabbits, which may be associated with its functions in promoting autophagy and suppressing apoptosis by up-regulating expressions of Beclin-1 and Bcl-2 mRNAs and proteins and down-regulation of Caspase-3 mRNA and protein.