Fig. 6

a Cumulative sGAG loss as a percent of total initial tissue GAG versus time, from representative donor #11, was significantly higher on day 14 in CBS (+) and CBS+INJ (#) groups versus CB. Data are mean ± SD of 5–6 technical replicates at each time point. b Tissue GAG (sGAG remaining in cartilage) for all donors for each treatment condition showed significantly higher loss in the presence of synovium explants (i.e., CBS or CBS+INJ) versus their absence (C or CB). Average values were first obtained for the 5–6 technical replicates at each time point for each donor; data are the mean cross all donors ± 95% C.I. Significant differences were observed in GAG content of C vs CBS (green+) and C vs CBS+INJ (blue+) from day 2. Tissue GAG was significantly lower starting day 2 in CBS vs CB (green#) and CBS+INJ vs CB group (blue#). Refer to Supplementary Table S4 for pairwise p values. c Release of ARGS-aggrecan fragments from representative donor #11 tissues on days 2, 7, and 14 to assess aggrecanase-mediated aggrecan degradation. Each bar represents the mean of pooled spent media samples obtained from n = 5–6 technical replicates. d Concentrations of ARGS-aggrecan fragments released to the medium from all donors on days 2, 7, and 14. Compared to CB, significantly higher levels of ARGS-aggrecan fragments were released in CBS and CBS+INJ groups in the early phase of culture (i.e., days 2 and 7; marked by horizontal lines). Each circle represents the mean of pooled spent media samples obtained from 5–6 technical replicates for a given donor; the bar is the median value for all donors assessed for each treatment condition at days 2, 7, and 14 (see Table S1-Biochemistry). C, cartilage monocultures, N = 5; CB, CB cocultures, N = 10; CBS, CBS cocultures, N = 5; CBS + INJ, disease group, N = 6