MiR-29b参与大鼠膝骨关节炎引起的软骨退变和股四头肌萎缩

Mi R-29b is involvement in cartilage autophagy and muscle atrophy resulting from knee osteoarthritis in rats*

目的:探讨mi R-29b在膝骨关节炎(knee osteoarthritis,KOA)大鼠软骨自噬和肌肉萎缩中的作用及机制。方法:SD大鼠按随机数字表法分为对照组、KOA组、KOA+miR-NC antagomir组、KOA+mi R-29b antagomir组。前交叉韧带离断术诱导KOA,术前1周膝关节注射mi R-NC antagomir或mi R-29b antagomir。30天后取材,验证造模是否成功;检测肌肉和软骨中miR-29b含量及miR-29b antagomir对软骨退变、自噬、凋亡和肌肉萎缩的影响;检测萎缩相关蛋白MuRF1和Atrigon-1的表达,以及肌肉中PI3K、p-AKT、P70的表达。结果:q PCR显示antagomir可下调关节和肌肉中的mi R-29b;负重实验表明,抑制mi R-29b改善关节功能;HE、PAS染色和WB显示下调mi R-29b抑制肌肉萎缩;免疫组化显示抑制mi R-29b可通过激活软骨中LC3和beclin-1增加自噬;免疫荧光和WB显示mi R-29b下调影响IGF/PI3K/AKT信号。结论:mi R-29b antagomir对KOA后软骨自噬和肌肉萎缩具有治疗作用,mi R-29b可作为KOA潜在治疗靶点。

Objective:To investigate the role and mechanism of miR-29b in cartilage autophagy and muscle atrophy in rats with knee osteoarthritis(KOA).Methods:SD rats were randomly divided into control group,KOA group,KOA+miRNC antagomir group,and KOA+miR-29b antagomir group.KOA was induced by anterior cruciate ligament amputation,and miR-NC antagomir or miR-29b antagomir was injected into the knee one week before surgery.After 30 days,the materials were collected to verify the success of the modeling;the content of miR-29b in muscle and cartilage and the effect of miR-29b antagomir on cartilage degeneration,autophagy,apoptosis and muscle atrophy were detected;the expression of atrophy-related proteins MuRF1 and Atrigon-1 was detected.expression,and expression of PI3K,p-AKT,P70 in muscle.Results:q PCR showed that antagomir could down-regulate miR-29b in joints and muscles;weight-bearing experiments showed that inhibition of miR-29b improved joint function;HE,PAS staining and WB showed that down-regulation of miR-29b inhibited muscle atrophy;immunohistochemistry showed inhibition of miR-29b can increase autophagy by activating LC3 and beclin-1 in cartilage;immunofluorescence and WB showed that downregulation of miR-29b affects IGF/PI3K/AKT signaling.Conclusion:mi R-29b antagomir has therapeutic effects on cartilage autophagy and muscle atrophy in KOA,and miR-29b can be a potential therapeutic target for KOA.