Figure 4

Matrix metalloprotease and aggrecanase gene expression and MMP-9 activity in mice immunized for collagen-induced arthritis. (a) Matrix metalloprotease (MMP)-3, MMP-9, MMP-13, ADAMTS-4 and ADAMTS-5 gene expression levels in joints following collagen-induced arthritis (CIA) (n = 6 for each group). C57 → u-PA^-/- mice, P < 0.01, MMP-9; P < 0.001, MMP-3, ADAMTS-4; and P < 0.0001, MMP-13. C57 → u-PA^-/- vs. u-PA^-/- mice, P < 0.05, MMP-9, MMP-13, and ADAMTS-4; P < 0.0001, MMP-3. Expression levels were normalized to an endogenous control (TATA-binding protein (TBP)) and calibrated relative to expression in C57BL/6 mice. Values expressed as mean level ± standard error of the mean. (b) MMP-9 levels in joint washouts, measured by zymography, from C57BL/6 and u-PA^-/- mice with no arthritis (-), mild arthritis (+) or severe arthritis (+++). Joint washouts were pooled (n = 3).