Experimental Study Of Synovial Mesenchymal Stem Cell Exosomes Transfected With MiR-145 On Osteoarthritis

Objective:To research the result of mi R-145 transfected exosomes originate from synovial mesenchymal stem cells in the treatment of osteoarthritis.Methods:Synovial tissue of patients undergoing knee arthroscopy,separate and culture of synovial mesenchymal stem cells.mi R-145 was transfected into synovial mesenchymal stem cells with lentivirus as vector.Empty virus was used as control to extract exosomes.They were divided into empty virus group（SMSC-Exos group）and infection group（SMSC-145-Exos group）.The expression of mi R-145 was detected by q PCR.Twenty male SD rats,they were randomly divided into four groups,five rats in each group,bilateral knee joint modeling was performed,normal group（n=10）,OA group（n=10）,OA+SMSC-Exos group（n=10）and OA+SMSC-145-Exos group（n=10）.The osteoarthritis model was established by cutting off the medial collateral ligament,posterior cruciate ligament,anterior cruciate ligament and medial meniscus of both knees in rats.Fifty rats in OA+SMSC-Exos group were injected into the knee joint cavityμL(10¹¹particles/ml)empty viral exosomes.OA+SMSC-145-Exos group was injected with the same dose of mi R-145 exosomes of lentivirus infected synovial mesenchymal stem cells.Rats in normal group and OA group were break in the same amount of physiological saline each time for 30 days,once every 3 days.Cartilage damage was measured by HE dyeing and Mankin score.The expressions of collagenⅡ、aggrecan and SOX9 in rat cartilage were detected by Western blot.Results:According to the results of fluorescence quantitative experiment,compared with the control group,the expression of mi R-145m RNA in SMSC-145-Exos group was obviously increased（P<0.05）.Contrasted with the normal group,the Mankin score in OA group was higher（P<0.05）.Compared with OA group,Mankin scores in OA+SMSC-Exos group and OA+SMSC-145-Exos group were lower（P<0.05）.Compared with OA+SMSC-Exos group,the Mankin score of OA+SMSC-145-Exos group was lower（P<0.05）.The expression levels of cartilage differentiation marker genes collagenⅡ、aggrecan and SOX9in OA group were significantly lower（P<0.05）,compared with the normal group,and the expression levels of collagenⅡ、aggrecan and SOX9 in SMSC-Exos group and SMSC-145-Exos group were obviously greater than those in OA group（P<0.05）.Conclusion:Intraarticular injection of SMSC-145-Exos can significantly inhibit cartilage degeneration and improve cartilage repair function in osteoarthritis rats.SMSC-145-Exos can play a cartilage therapeutic role by up regulating the expression of collagenⅡ、aggrecan and SOX9 in the cartilage of OA rats.