Figure 3.

Mitogenic effect of tPA is independent of its protease activity. A: After treatment with nonenzymatic mutant tPA (NE-tPA, 10 nmol/L) for one hour, NRK-49F cells were subjected to Western blot with anti-phospho GSK3β and α-tubulin antibodies. B: NRK-49F cells were treated with NE-tPA (10 nmol/L) for 48 hours, and cell growth was assessed by WST-8 assay. **P < 0.01 (n = 4). C: MMP-9 did not affect fibroblast proliferation. NRK-49F cells were incubated with MMP-9 (10 nmol/L) for 48 hours and then subjected to WST-8 assay.