FIGURE 3.

Stat3 activation is required for TGF-β-mediated CTGF production. A, CFSC-2G (CFSC) cells were transfected with Stat3 or control siRNA for 48 h, followed by exposure to 5 ng/ml TGF-β1 as indicated. Lack of Stat3 resulted in reduced CTGF production. Knockdown was verified at protein level by measurement of total Stat3 and p-Stat3. B, Stattic, a chemical inhibitor, was added to CFSC-2G cells and hTERT HSCs 30 min prior to TGF-β1 treatment to blunt Stat3 phosphorylation. CTGF expression was analyzed by Western blot. Stattic interfered with TGF-β-induced CTGF in a dosage-dependent manner in both cell lines. Data are expressed as a ratio of CTGF to GAPDH and are means ± S.E., p < 0.01 and p < 0.001 indicate the statistical significance. DMSO, dimethyl sulfoxide. ut, untreated; siCo, siControl.