FIGURE 5.

TGF-β stimulated Stat3 activation requires de novo protein synthesis. A, CFSC-2G cells and hTERT HSCs were pre-incubated with 1 μg/ml actinomycin D (ActD) or 10 μg/ml cycloheximide (CHX) for 30 min prior to TGF-β1 (5 ng/ml) treatment. TGF-β-induced Stat3 phosphorylation was blocked by both inhibitors. B, CFSC-2G cells were treated with or without TGF-β1 (5 ng/ml) for 1 h, and conditioned media were collected and added into new cell cultures (after overnight starvation). Western blot analysis did not detect earlier Stat3 activation and CTGF expression in conditioned (cond.) media-treated cells. DMSO, dimethyl sulfoxide.