Research On The Kartogenin Induces Synovial Mesenchymal Stem Cells Differentiation Into Cartilage And Repairs Of Cartilage Defect

Objectives: To explore the effect of Kartogenin(KGN)on inducing synovial mesenchymal stem cells(SMSCs)differentiating into cartilage,compared with the combination of TGF-beta 3,BMP-2 and DXM.Based on this,we explored preliminarily the effect of KGN combined with SMSCs to repair rabbit’s cartilage defects for the foundation of further experiments.Methods: 1.SMSCs were extracted from the knee joints of synovial tissue of New Zealand white rabbit.SMSCs were identified by morphological observation and the ability of differentiation to adipocyte osteocyte and chondrocyte.2.SMSCs were divided into three groups.Each group was accordingly added KGN,compound of transforming growth factor-β3(TGF-β3),bone morphogenetic protein-2(BMP-2),and dexamethasone(DXM)and DMSO for blank control.The PELLET cultivation system were used for cell culture..By compared the expression of cartilage marker gene and protein of cell pellets from each group,we evaluated the ability of KGN inducing differentiation from SMSCs to cartilage.3.After building New Zealand white rabbit cartilage defect model,we divided these rabbits into three groups and rabbits in each group were injected accordingly into KGN combined with SMSCs,SMSCs and DMSO for blank control.All rabbits were killed after 12 weeks.We evaluated the difference of ability of cartilage repair in each group by comparingtheir morphological observation,histomorphology score,hematoxylin-eosin staining and safranin O staining in new tissue.Results: 1.Results from flow cytometry revealed that the specific surface antigen CD44,CD105 and CD90 are positively expressed in SMSCs,and CD45 negatively.The isolated stem cells have the specific phenotype of mesenchymal stem cells and have potential of proliferation and multidirectional differentiation.2.In the study of the effect of KGN on inducing the differentiation from SMSCs to chondrocyte,we found KGN group presented larger diameter and heaviest weight of cell pellets,and higher synthesis of proteoglycan and collagen type II.QRT-PCR results showed that higher expression of cartilage marker gene and protein in KGN group..3.In the study of contribution of KGN to SMSCs’ ability of reparing the cartilage defect,after 12 weeks,hyaline cartilage were appered in the postion of cartilage defect in KGN combined with SMSCs group,with highest scores and largest red area of safranin O staining than other groups.Conclusion: 1.The stem cells isolated have the specific phenotype of mesenchymal stem cells and have the potential of proliferation and multidirectional differentiation.2.KGN could enhance the capacity of chondrogenic differentiation of SMSCs.3.KGN could promote the capacity of the cartilage repair of SMSC.