Fig. 1.

TGF-β1 induces proMMP-9 expression. (A) HSC-3 cells were stimulated with TGF-β1 at indicated concentrations for 24 h. CM were analyzed by gelatin zymography and immunoblotted with anti-MMP-9 antibody. (B) HSC-3 cells were stimulated with TGF-β1 (10 ng/mL) in Opti-MEM for 24 h. QRT-PCR was performed to detect the expression of MMP-9. The error bars are SD of the mean values obtained from three independent experiments. *p < 0.01. (C) HSC-3 cells were treated with proMMP-2 and TGF-β1 (10 ng/mL) for 24 h. After that, Con A (50 ng/mL) was added and incubated for 24 h. Cell-associated MMP-2 and MMP-9 were analyzed by gelatin zymography (Cell). (D) HSC-3 cells were transfected with siRNA against negative control (NC), MMP-9-1, or MMP-9-2 for 48 h. Then, cells were treated with Con A, proMMP-2, and TGF-β1 (10 ng/mL) as described above. Cell-associated MMP-2 and MMP-9 were analyzed by gelatin zymography.