Towards Identifying Proteins in the Synovium Promoting Articular-cartilage Differentiation

Abstract: Skeletal development begins when mesenchymal stem cells migrate, condensate and differentiate into chondrocytes. The chondrocytes differentiate in one of two ways. Either the cells form the cartilaginous template for endochondral ossification or they form the articular cartilage which express proteoglycan 4. The underlying mechanisms for articular cartilage formation are poorly understood. The purpose of this study was to assess the effect of different fractions of synoviocyte-conditioned medium on chondrocyte differentiation. We show evidence that Synovial-like fluid contains a protein which promotes chondrocytes to express proteoglycan 4, thus promoting articular cartilage formation. The synovial-like fluid was fractionized by size exclusion chromatography and reversed phase chromatography and thus, with that method, this manuscript lays the foundations for further research to identify the putative factor. Because of this study, we are now closer in identifying the proteins that promote articular cartilage formation.