MMP activity in each experimental group.

<p><b>A</b>: MMP-8 increased after bleomycin instillation. As expected, no MMP-8 was detected in knockout mice (n≥7 per group). <b>B–C</b>: Collagenolytic activity of lung tissue homogenates from wildtype and knockout mice 3 days (B) and 3 weeks (C) after bleomycin instillation (n = 3 per group). There are no significant differences between genotypes. <b>D</b>: MMP-9 has an acute increase after bleomycin instillation only in knockout mice (n≥7 per group). <b>E</b>: MMP-2 increases in both wildtype and knockout mice 3 weeks after injury (n≥7 per group). <b>F</b>: Representative western blotting and gelatin zymography used to quantify these MMPs. G–H: Immunohistochemical staining of MMP-8 (G) and MMP-9 (H) after bleomycin instillation. ^1,2,3p<0.05 in post-hoc test when compared against 3 days (1), 3 weeks (2), 6 weeks (3) within the same genotype and treatment; *p<0.05 when compared against wildtype within the same time and treatment; ^#p<0.05 when compared against saline within the same time and genotype.