Figure 6

Effect of rheumatoid arthritis and osteoarthritis synovial fluid on the chondrogenic differentiation of CSP. Differential expression of maker genes in CSP treated with synovial fluid from ND, OA and RA donors. To assess the effect of rheumatoid arthritis and osteoarthritis on the "normal" chondrogenic differentiation of subchondral progenitors, the expression profile of the typical chondrogenic marker genes aggrecan, cartilage oligomeric matrix protein (COMP), link-protein type II and type IX collagen was evaluated. Matrix remodelling was assessed by gene expression analysis of the matrix metalloproteinases (MMP)-1, -2 and -13 as well as their inhibitors (TIMP)-1 and -2 and is given as fold change compared to the expression level in CSP treated with normal synovial fluid. The mean of each triplicate well is plotted and the error bars represent SD.