454. The Surface Marker Expression Changes in Monolayer Cultured Human Chondrocytes by TGF-β1

Abstract

Due to avascular environment, damaged or defective cartilage cannot be recovered voluntarily without intervention of a medical treatment. Among the treatments, autologous or allogenic chondrocyte transplantation is considered as one of promising methods. However, because the cell number that can be driven from a patient or a donor is limited, isolated chondrocytes should be in vitro cultured for amplification before being applied to a patient. This strategy was hindered again with dedifferentiation of monolayer cultured chondrocytes. Dedifferentiated chondrocytes change the phenotype and ECM profiles toward fibroblast-like ones, eventually resulting in insufficient recovery of cartilage. Previously, we showed that chondrocytes supplemented with TGF-β1 could be redifferentiated similar to articular chondrocytes. In this study, we investigated surface markers expressed on dedifferentiated chondrocytes utilizing flow cytometry analyses. The investigated markers include integrins and adhesion molecules like CD44, CD49a, CD49c, CD54, CD106, CD166, tetraspnins like CD9 and CD151, receptors like CD14 and CD105, and ectoenzyme, CD10. When compared to their expression pattern on chondrocytes cultured in TGF-β1 supplemented media, several markers showed differences in their expression levels, for example, such as up -regulation of CD49a and down-regulation of CD105 with TGF-β1 supplemented culture. The result seems supporting our previous study that showed chondrocyte redifferentiation by TGF-β1 and we speculate that the surface marker analysis would be applicable as a testing method to determine the potency and the comparability of chondrocytes originated from different donors and/ or from different manufacturing batches.