Gelatinolytic activities in IPF versus donor (control) lungs.

<div><p>A–C: Representative zymogram of gelatin substrate zymography of homogenates of control and IPF lungs (A); lytic zones of MMP-2 and MMP-9 activity appear white over the dark background. Densitometric analysis of pro- and active-MMP-2 activity (B); and of pro- and active MMP-9 activity (C). **<i>p < 0.01</i> IPF compared with controls.</p> <p>D–G: Representative photomicrograph of H&E stain of cryo-sectioned IPF lung tissue (D) and (F), and gelatinase in situ zymography combined with immunohistochemistry for MMP-2 and MMP-9. MMP-2 antigen signal was dot-like in pattern, localized mostly to alveolar and luminal cells and co-localized with gelatinase activity in hyperplastic epithelia (E, G). MMP-9 antigen also showed a dot-like pattern of expression, localized both to the airways and lung parenchyma, and but with limited co-localization with gelatinase activity (g) (Blue = nuclei, green = gelatinolytic activity, red = MMP-2 antigen in (E) or MMP-9 antigen in (G). Original magnification = 10X, scale = 100µm.</p>