-mediated release of proMMP-2 sequestered in cirrhotic liver tissue. (A) Cryostat sections of cirrhotic human liver tissue were fixed, stained with Sirius red for collagens and counterstained with Haemalaun. (B-D) Serial sections of the same liver tissue sample were incubated with 60 ng of Cy2-proMMP-2 in the dark for 24 h before unbound Cy2-proMMP-2 was removed by washing. (B) Slides were treated with Cy2-proMMP-2 alone. (C) Cy2-proMMP-2 was mixed with a 10-fold molar excess of (GPO)10 before being added to the slides. (D) Cy2-proMMP-2 was allowed to bind before a 10-fold molar excess of (GPO)10 was applied. Original magnification, ×40; scale bars, 200 μm.