The Protective Mechanism Of SIRT1 On Cartilage Through Regulation Of LEF-1

Objective To expl ore the mutual regul ation of Silent Inforrmation Regul ator 1(SI RT-1)and related factors in different degrees of osteoarthritis(OA).Method First,randomly select 10 fresh tibial plateau specimens from patients with knee osteoarthritis after total knee arthroplasty.According to the results of safranin O fast green stai ni ng and hematoxyl i n-eosi n stai ni ng,the speci mens were di vi ded into mild,moderate and severe groups,and the cartilage destructi on was assessed accordi ng to the OARSI score established by the International Association for the Study of Osteoarthritis;Immunization was used Histocherrical analysis of the expression of Silent Information Regulator 1(SIRT-1)and Lyrrphocyte Enhancer Factor 1(LEF-1)in cartilage specimens,and then select 72 C57BL/6J mice,using the medial meniscus Destabilization of the medial meniscus(DMM)caused knee osteoarthritis in mice.Randomly divide them into normal group(sham),model(model)and spraying group(srt),and each group was further divided into 2 weeks(2w)after modeling and 8 weeks(8w)after model i ng accordi ng to the time after modeling.Using Safranin O fast green staining OARSI score to assess the degree of degenerati on of mouse knee cartilage specimens;Assessing the expression of SI RT-1,β-catenin,MMP-13 and Collagen Ⅱ in cartilage specimens according to immunohi stochemi cal techniques;The expression of β-catenin,LEF-1 and MMP-13 in the specimen was evaluated according to the immunohi st of luorescence technique;Use Quantitative Real-time PCR(qPCR)to evaluate the mRNA expression ofβ-catenin and LEF-1 in mouse cartilage specimens.Results Human cartilage specimens:According to the results of Safranin O fast green staining,the cartilage layer structure of the moderate and severe groups was destroyed,the nurrber of cartilage cells was reduced and the cell hypertrophy,and the cartilage surface was di sconti nuous.The OARSI score was I n the severe group,the cartilage specimens have severe cartilage damage,and the OARSI score is the highest;according to the analysis of immunohistochemical techniques,compared with the sham 2w group and the sham 8w group,β-catenin in the cartilage specimens of the model 2w group and the model 8w group,the expression of LEF-1 and MMP-13 increased significantly,and the expression of SIRT-1 and Collegan Ⅱ decreased significantly(P<0.05).The results of the srt 2w and srt 8w groups were between the sham group and the model group;accordi ng to immunofluorescence technol ogy The analysis showed that compared with the sham2w group and the sham8w group,the expressions of β-catenin,LEF-1 and MMP-13 in the model 2w group and the model 8w group were significantly increased,while the expressions of the srt 2w group and the srt 8w group The result is between the sham group and the model group;according to the real-time qPCR results:Compared with the sham2w group and the sham8w group,the mRNA expression of β-catenin in the model 2w group and the model 8w group was significantly reduced,the LEF-1 The mRNA expression of srt 2w group and srt 8w group was significantly higher than that of srt 2w group and model group.Conclusion:SIRT-1 may regulate the expression of LEF-1 and related inflammatory factors in OA to play a chondroprotective effect.