Effect of Needle-Warming Moxibustion on Transcription Level of Caspase-3 and Caspase-9 in Cartilage Tissue of Rats with Knee Osteoarthritis
Objective:To analyze the effect of needle-warming moxibustion on transcription levels of Caspase-3 and Caspase-9 in cartilage tissue of knee osteoarthritis(KOA)model rats,so that to explore the possible mechanism of needle-warming moxibustion(NWM)in the treatment of KOA.Methods:A total of 24 SPF male SD rats aged 8 weeks were randomly divided into the blank group,model group and NWM group,with 8 in each group.Establishing KOA models using 4%papain injection in the model and NWM groups,while the blank group received no treatment.The knee joint of rats enlarged and showed pain response to local stimula-tion,with Lequesne MG behavioral score ≥3,which indicated that the KOA models were successfully established.Then the NWM group acuputured bilateral Xiyan and Dubi acupoints,the depth was about 5 mm.Placing a small section of moxa stick onto the han-dle of an inserted needle and igniting it.The moxibustion was carried out for twice,and the retention of needle was for 20 minutes.The blank and model groups were equally captured and fixed for 20 minutes without any treatment once a day.All the three groups were intervened for 6 days a week and rested for 1 day for 2 weeks.The Lequesne MG score was used to evaluate the behavioral per-formance of rats,the HE staining and the safranin-fast green staining methods were used to observe the morphological changes of knee cartilage,the Mankin's scoring system was used to evaluate the degree of cartilage degeneration,and the TUNEL staining was used to observe the apoptosis rate of cartilage cells from knee joints of rats in the three groups.The transcription level of Caspase-3 and Caspase-9 mRNA in knee cartilage were detected by qPCR.Results:Compared with the blank group,the Lequesne MG score in the model group significantly increased(P<0.05).The result of HE staining showed that the structure of all layers of the knee cartilage tissue was unclear,surface defects and cracks appeared,the number of chondrocyte diffuse increased or locally decreased,and the arrangement of chondrocytes was disordered.The result of safranin-fast green staining showed uneven saffranin staining of cartilage matrix,increased staining range of solid green,unclear tide line;the Mankin's score and the apoptosis rate of knee cartilage tissue cells increased(P<0.05),and no significant increase in Caspase-3 transcription level(P>0.05).The transcription level of Caspase-9 mRNA increased(P<0.05).Compared with the model group,the Lequesne MG score of the NWM group was lower(P<0.05),the HE stain-ing result showed the surface layer of knee cartilage tissue was relatively flat,the number of chondrocytes increased diffusely and arranged irregularly,but it was better than the model group,the safranin-fast green staining showed that no obvious abnormality was found in matrix staining and the tide line was clear;and the Mankin's score decreased(P<0.05).The apoptosis rate of knee cartilage cells was decreased(P<0.05),the transcription level of Caspase-3 mRNA didn't significantly decrease(P>0.05),while the transcrip-tion level of Caspase-9 mRNA decreased(P<0.05).Conclusion:Needle-warming moxibustion can effectively protect the function of knee joint,inhibit the apoptosis of chondrocytes and delay the degeneration of KOA cartilage,the mechanism of which may be related to the regulation of transcription level of Caspase-9 mRNA.