A Study On The Mechanism Of Action Of Needle Knife Therapy On The Apoptosis Of Chondrocytes In Rabbits With Knee Osteoarthritis Via Regulating The IRE1-JNK-Caspase-9 Signaling Pathway

ObjectiveTo investigate the effect of needle knife therapy on the apoptosis of chondrocytes in rabbits with knee osteoarthritis(KOA)and its mechanism of action.MethodsAccording to the random number table method,thirty-five New Zealand rabbits were divided into normal group,model group,needle knife group,and medicine group,with 8 rabbits in each group.The KOA model was established by Vidman method.Knee joint chondrocytes ultrastructure was observed under transmission electron microscopy(TEM);Apoptosis of articular cartilage was compared by terminal deoxynucleotidyl transferase d UTP nick end labeling(TUNEL);The expression levels of the inositol-requiring protein 1(IRE1)and the endoplasmic reticulum stress(ERS)marker molecules X-box binding protein 1(XBP1)and c-Jun N-terminal kinase(p-JNK)and cysteinyl aspartate specific proteinase-9(Caspase-9)in the endoplasmic reticulum between groups were detected by real-time quantitative PCR(q RT-PCR)and Western blot(WB).These techniques were used to investigate the effects of needle knife therapy and diclofenac diethylamine emulgel on the apoptosis of knee articular chondrocytes and the m RNA and protein expression of the IRE1–JNK–Caspase-9 signaling pathway in the rabbit model of KOA and its mechanism of action.Results1 Effect of needle knife therapy on knee joint activity evaluated by Lequesne MG score: The model group had a significantly higher total score than the normal group,while the needle knife group and the medicine group had significantly lower total scores than the model group(P<0.05).2 Effect of Needle Knife Therapy on Knee Joint Chondrocytes Ultrastructure:Some nuclear membranes of chondrocytes disappeared in the model group,the chromatin in chondrocyte nucleus was accumulative and the edge set was obvious;The nucleus was slightly condensed;The rough endoplasmic reticulum in the cytoplasm was broken and reduced and the mitochondria have vacuolar degeneration;The nuclear membrane structures in the needle knife groups and medicine groups were essentially complete and the nucleus chromatin was less pronounced,rough endoplasmic reticulum fracture and vacuolar degeneration of mitochondria were observed in cytoplasm.3 Comparison of apoptosis of knee articular chondrocytes between groups:The apoptosis of chondrocytes was significantly increased in the model group than in the normal group,while the apoptosis of chondrocytes in needle knife group was significantly reduced compared with that in the model group and the medicine group(P<0.05).4 Expression levels of IRE1,XBP1,JNK,Caspase-9m RNA and protein in each group: The m RNA and protein expression levels of IRE1,XBP1,JNK and Caspase-9 in the knee cartilage of rabbits in the model group were significantly higher than those in the normal group,while the m RNA and protein expression levels of IRE1,XBP1,JNK and Caspase-9 in the needle knife group were significantly reduced compared with those in the model group and the medicine group(P<0.05).Conclusion1 Needle knife therapy can relieve pain,improve joint mobility,correct gait,and restore joint function.2 Needle knife therapy can promote cartilage cell repair and interfere with chondrocyte apoptosis by ERS.It can reduce IRE1,XBP1,JNK,Caspase-9 gene and protein expression related to cell apoptosis.The effects of needle knife therapy on the apoptosis of knee articular chondrocytes may be related to its inhibition of ERS and regulation of the IRE1–JNK–Caspase-9 signaling pathway.