Figure 3.

Curcumin induces SS-mediated expression of uPA and tPA. RGC-5 cells were left untreated or treated with the indicated concentrations of curcumin in the absence (top) or presence (bottom) of SS. Forty-eight hours after the treatment, conditioned medium was collected and proteolytic activities of tPA and uPA were determined by zymography assays. Zymography assays indicate that untreated RGC-5 cells expressed low levels of uPA (but not tPA; top), whereas SS-treated cells expressed increased levels of both tPA and uPA (bottom). In addition, whereas higher concentrations of curcumin (>25 μM) decreased the expression of uPA and tPA, lower concentrations (<25 μM) increased their expression.