In Vitro Study On Differentiation Potential Of Synovium-derived Mesenchymals Stem Cells And Bone Marrow Mesenchymal Stem Cells

Mesenchymal stem cells are applied in tissue engineering as seed cells due to theself-renewal capacity and the ability to differentiate into mesenchymal lineagesincluding bone，cartilage，fat，muscle and nerve. Bone marrow mesenchymal stemcells have been considered to be the progenitor cells for bone tissue engineering, andsynovium-derived mesenchymal stem cells, as a new member of the family of stemcells, have been described as promising seed cells owing to the greater chondrogenicpotential. Hence, it is of important clinical significance to explore how to utilize thedifferentiation potential of these two cell types in tissue engineering efficiently.Objective:BMSCs and SMSCs were isolated and their osteogenesis and chondrogenesis assaywere performed. The multilineage potential of SMSCs was verified by cell staining.Their osteogenic and chondrogenic ability was compared by quantitative analysis ofthe gene expression level with real-time PCR, in order to determine the favorableseeding cells for bone or cartilage regeneration respectively.Methods:The whole bone marrow adherent culture method was carried out to isolate BMSCs.Random biopsies were isolated from the knee joints of New Zealand white rabbit, andSMSCs were obtained by enzyme digestion. Cellular morphology and growth ratewere observed in the process of culture in monolayer. At passage3,osteogenesis，adipogenesis and chondrogenesis assay were performed. MSCs were cultured inDMEM as negative control. After inducing completed alizarin red staining, oil red Ostaining, alcian blue staining and Immunohistochemistry were carried out. On theother hand, gene expression level was tested to compare the osteogenic andchondrogenic ability of MSCs from two resources by RT-PCR.Results:1.The primary BMSCs morphology performed spindle shaped or polygonal and cellswere arranged serried. The growth rate was originally slow, however, cells reached80%confluence at day7.As to SMSCs, the primary cells appeared to befibroblast-like cells, arranged serried and had a greater growth rate, at day5cellsreached80%confluence.2. The osteogenesis and adipogenesis were observed after cell staining. Besides, collagen Ⅱ, Collagen Ⅹ and GAG were detected byimmunohistochemical staining.3.The expression of osteogenetic genes (collagenⅠ,osteocalcin and Runx-2) in BMSCs was significantly higher than that in SMSCs(P＜0.05), however, the expression of chondrogenetic genes (collagenⅡ, Sox-9) wassignificantly upregulated in SMSCs compared with that in BMSCs (P＜0.05).CollagenⅩin two groups had no statistically significant differences.Conclusion:1. SMSCs possess typical biological characteristics of MSCs including highself-renewal ability and the capacity of differentiating into mesenchymal lineagesincluding bone，cartilage and fat.2. SMSCs have a greater chondrongenetic potentialthan BMSCs. On the contrary, BMSCs have a greater osteogenetic capacity thanSMSCs. Therefore, SMSCs could be the optimal seed cell for cartilage regenerationand BMSCs perform better in bone engineering.3. This article compared theosteogenetic and chondrongenetic ability which are applied in tissue engineering ofBMSCs and SMSCs and the results provide theoretical criterion for the selection ofseed cells in tissue engineering.