Figure 5.

Time course of MMP-13 induced -degradation of lumican. Human articular cartilage extracts were incubated with APMA-activated MMP-13 for the indicated times (0–16 hours). Panels are for extracts from (a) normal (nonfibrillated) cartilage and from (b) slightly, (c) moderately and (d) severely fibrillated OA cartilage. The bottom panel (e) relates to the extract from moderately fibrillated OA cartilage incubated for 16 hours with APMA-activated MMP-13 in the absence or presence of 50 or 1 nmol/l RS 110–2481 (a preferential MMP-13 inhibitor). APMA, aminophenylmercuric acetate; MMP, matrix metalloprotease; OA, osteoarthritis; rh, human recombinant.