Figure 2
tPA promotes myofibroblast activation by a mechanism independent of its protease activity.
(A) Plasmin inhibitor aprotinin (50 U/ml) did not affect the synergistic effect of tPA with TGF-β1 (0.5 ng/ml) on α-SMA induction in NRK-49F cells. (B) Zymographic analysis demonstrates that aprotinin (50 U/ml) was able to block the proteolytic activity of plasmin. (C) Non-enzymatic mutant tPA retained the ability to synergistically promote α-SMA expression induced by TGF-β1. NRK-49F cells were incubated with mouse recombinant non-enzymatic tPA in the absence or presence of TGF-β1, as indicated.
