Conditional regulation of TGF-β1 expression in mice. (A) Serum TGF-β1 levels in hydrodynamics-based gene transferred mice. Values are represented as mean ± SD. *, p < 0.01; compared with pPK9a alone (48 h); #, p < 0.05; compared with pPK9a + ZnSO4 (24 h); and, p < 0.05; compared with pPK9a + ZnSO4 (48 h); unpaired t-tests. (B) RT-PCR analysis for TGF-β1 mRNA expression at 48th h in the liver of gene transferred mice after injection with pPK9a. (C) Protein expression of TGF-β1 and α-SMA at 48th h in gene transferred mice after injection with pPK9a. (D) Photomicrographs of immunohistochemical analysis (upper panel) and bright field (lower panel) for TGF-β1 expression at 48 h in liver sections: I. Ringer's solution + pPK9a and ZnSO4free. II. Ringer's solution only. III. Ringer's solution + pPK9a + ZnSO4. Bar = 0.2 mm. (E) TGF-β1 protein expression between 1 to 5 days.