Figure 3.

Plasminogen-dependent elastolysis and processing of MMP zymogens by human MDMs. (A) Human MDMs were cocultured with [³H]elastin in the upper well of a transwell insert with 50 μg/ml plasminogen (plg) in the absence or presence of the indicated inhibitors. Results are shown as μg elastin degraded/10⁶ cells for 5 d (mean ± SEM; n = 3). Western Blots: MDMs and elastin were cocultured without contact in the presence of 50 μg/ml plasminogen and/or 100 μg/ml aprotinin for 5 d. The processing of progelatinase B (B), prometalloelastase (C), and promatrilysin (D) in the presence of plasminogen was assessed by Western blot analysis in samples recovered from conditioned media or the elastin surface. The proforms (open arrowheads) and mature (arrows) forms of enzymes are indicated. The processing of the proforms by 4-aminopherylmercuric acetate or trypsin are shown at the far right of each panel with the proforms (open arrowheads) and mature (arrows) forms depicted. Results are shown from a single representative experiment of three performed.