Figure 7.

Serpine2 deficiency results in increased lung thrombin activity. A, B) Total lung protein and BAL fluid collected from CTL or SE2^−/− (KO) mice were tested for serine protease activity. A) Total lung protein from 2-mo-old KO mice showed an 8-fold increase in thrombin-specific proteolytic activity, whereas BAL fluid from similar aged mice had less profound increases. B) Total lung protein from KO mice showed a modest nonsignificant increase in uPA activity. C) Expression of plasmin/plasminogen pathway genes was assessed in whole-lung RNA from CTL or KO mice at 2 mo of age by qPCR. SE2^−/− mice showed decreased expression of both uPA and tissue plasminogen activator mRNA (n ≥ 5). Data are presented as means ± sem. ^#P < 0.05 by Mann–Whitney U test; *P < 0.05; **P < 0.09 by Student’s t test.