Profiling cathepsin activity in serum and synovial fluid of osteoarthritis (OA) patients.
(A) Non-OA/normal (N), early OA (E) and late OA (L) sera were labeled with GB123, separated by SDS PAGE, scanned for fluorescence and quantified for band intensity, following subtracting gel background (n = 10 per group). (B) non-OA (N) (n = 11), early OA (E) (n = 17), late OA (L) (n = 15) and rheumatoid arthritis (RA) (n = 10) synovial fluid (SF) were labeled with GB123, and analyzed similar to A. Plots of band intensity (imageJ software) show SD surrounding an average data point. Statistical analysis was by non-parametric Mann-Whitney analysis, assuming P <0.05 to be statistically significant. Within each plot a table depicts statistical significance (*P <0.05, **P <0.01, ***P <0.001) for cathepsin B and S activity upon comparison of the different groups.