RESUMEN
OBJECTIVE: To explore the effect of acupotomy intervention on autophagy of chondrocytes in rabbits with knee osteoarthritis (KOA), and to determine the possible mechanisms of acupotomy to alleviate cartilage degeneration. METHODS: The modified Videman method was used to construct a KOA rabbit model. After modeling, 40 rabbits were randomly divided into 4 groups by a random number table: control; KOA (model); KOA + acupotomy (acupotomy), and KOA + sham acupotomy (sham), 10 in each group. After a 3-week treatment course, the knee joint activity was determined by the modified Lequesne MG index. Hematoxylin-eosin staining staining was used to examine the morphological changes of chondrocytes. Autophagy of chondrocytes was observed by transmission electron microscopy. The surface morphology of cartilage tissue was observed by scanning electron microscope. The mRNA and protein levels of AMP kinase/mammalian target of rapamycin/Unc-51 (AMPK/mTOR/ULK1) signal pathway key proteins, autophagy-related factor Beclin-1 and microtubule-associated protein 1A/1B light chain 3 (LC3) in rabbit knee cartilage were assessed by real-time fluorescence quantitative polymerase chain reaction and Western blot, respectively. RESULTS: The modified Lequesne MG score of acupotomy group was significantly lower than that of model group (P<0.05). Pathological results showed that chondrocyte autophagy decreased and cartilage surface was rough in the model group, which recovered after acupotomy treatment. The mRNA expressions of AMPK, ULK1, Beclin-1 and the protein levels of p-AMPK, p-ULK1, Beclin-1, and LC3 II/LC3 I were decreased in the model group, while the mRNA and protein expressions of mTOR were increased (P<0.01). However, acupotomy treatment reversed these abnormal changes (P<0.05). CONCLUSIONS: Acupotomy could effectively up-regulate the expressions of AMPK, ULK1 and Beclin1, reduce the expression of mTOR, promote autophagy, and alleviate joint degeneration. Acupotomy is a promising complementary and alternative therapy for KOA.
RESUMEN
OBJECTIVE: To observe the effect of needle knife on chondrocyte autophagy and expressions of autophagy-related protein and mammalian target of rapamycin (mTOR) in rats with knee osteoarthritis (KOA), and to explore the possible mechanism of needle knife for KOA. METHODS: A total of 42 SD rats were randomly divided into a normal group, a model group and a needle knife group, 14 rats in each group. Except for the normal group, the other two groups were injected with the mixture of papain and L-cysteine into the left hind knee joint to establish the KOA model. After modeling, the rats in the needle knife group were treated with needle knife at strip or nodule around the quadriceps femoris and medial and lateral collateral ligament on the affected side, once a week for 3 times (3 weeks). The changes of left knee circumference in each group were observed; the chondrocytes and ultrastructure of left knee joint were observed by HE staining and electron microscope; the mRNA and protein expressions of autophagy-related genes (Atg5, Atg12, Atg4a), Unc-51 like autophagy activated kinase 1 (ULK1), autophagy gene Beclin-1 and mTOR in left knee cartilage were detected by real-time fluorescence quantitative PCR and Western blot. RESULTS: After modeling, the left knee circumferences in the model group and the needle knife group were increased compared with those before modeling and in the normal group (P<0.05); after intervention, the left knee circumference in the needle knife group was smaller than that in the model group and after modeling (P<0.05). Compared with the normal group, the number of chondrocytes was decreased, and a few cells swelled, nuclei shrank, mitochondria swelled and autophagosomes decreased in the model group; compared with the model group, the number of chondrocytes was increased , and most cell structures returned to normal, and autophagosomes was increased. Compared with the normal group, the mRNA and protein expressions of Atg5, Atg12, Atg4a, Beclin-1 and ULK1 in the knee cartilage in the model group were decreased (P<0.05); compared with the model group, the expressions of the above indexes in the needle knife group were increased (P<0.05). Compared with the normal group, the mRNA and protein expressions of mTOR in the knee cartilage in the model group were increased (P<0.05); compared with the model group, the expressions of the above indexes in the needle knife group were decreased (P<0.05). CONCLUSION: The needle knife intervention could improve knee cartilage injury in rats with KOA, and its mechanism may be related to reducing the expression of mTOR and up-regulating the expressions of Atg5, Atg12, Atg4a, ULK1 and Beclin-1, so as to promote chondrocyte autophagy and delay the aging and degeneration of chondrocytes.