Impaired uPA activity and fibrin clearance in uPAR−/− nerves after damage.

<p>(A) western blot analysis of fibrin and fibronectin in Wt and uPAR null sciatic nerve homogenate at 15, 21 and 45 dpc. Calnexin was used to normalize loading. Quantification of western blot is reported as an average of 3 independent experiments, and represented as ratio fibrin/calnexin, vitronectin/calnexin and fibronectin/calnexin, assigning Wt 0dpc as 1±SEM). At each time point uPAR null homogenate showed increased levels of fibrin and vitronectin as compared to Wt, whereas fibronectin levels were higher at 15 and 21 dpc, but lower at 45 dpc. (B) Zymography of sciatic nerve homogenate from Wt and uPAR null mice measuring tPA and uPA activity 0, 7 and 15dpc. Bands were stained with Coomassie blue as loading control. Quantification of zymography is reported as an average of 3 independent experiments, and represented as ratio uPA/coomassie blue and tPA/coomassie blue, assigning Wt 0dpc as 1±SEM. Note the reduced increase of uPA in uPAR null homogenate as compared to Wt 7 and 15dpc, whereas there are no differences in the tPA activity between mutant and Wt mice. Fg = fibrin; Fn = fibronectin; Vn = vitronectin; Cln = calnexin.