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. 2012 Oct;82(4):601–613. doi: 10.1124/mol.112.078147

Fig. 3.

Fig. 3.

Differential regulation of mouse Aldh1a1 and human collagenase transcriptional activity by AP-1. A, the Aldh1a1 promoter activity was transactivated by c-Jun proteins. HepG2 cells were transiently cotransfected with p2.0Aldh1a1Luc (spanning −1963 to +27 of the Aldh1a1 promoter), pGL3 Basic or pColTRELuc (containing human collagenase TRE) luciferase constructs, and 40 ng of c-Jun, c-Fos, or both expression plasmids. The normalized luciferase activity was determined, and data are means ± S.D. from at least three independent experiments. *, p < 0.05, significantly different from vector-transfected cells; **, p < 0.05, significant difference compared with c-Jun-transfected cells (one-way ANOVA followed by the Tukey test.) B, induction of Aldh1a1 transcription is mediated by the c-Jun homodimer and not by the c-Jun/c-Fos heterodimer. HepG2 cells were transiently cotransfected with either pColTRE-Luc (TRE control) or p2.0Aldh1a1Luc luciferase construct with a constant concentration of c-Jun (40 ng) and increasing concentrations of c-Fos (0–40 ng) expression plasmid. Luciferase activity was normalized to β-galactosidase activity. The results are expressed as the fold induction from at least three independent experiments compared with that for control vector transfected cells. *, p < 0.05, significantly different compared with c-Jun-transfected cells (one-way ANOVA followed by the Tukey test). C, inhibition of c-Jun-mediated transactivation of Aldh1a1-luciferase activity by c-Jun dominant-negative (TAM67) protein. HepG2 cells were transiently cotransfected with the p2.0Aldh1a1Luc reporter with c-Jun, TAM67, or both expression plasmid and normalized luciferase activity (mean ± S.D. from at least three independent experiments) was measured. *, p < 0.05, significantly different compared with vector-transfected cells; **, p < 0.05, significantly different compared with acrolein-treated cells; ***, p < 0.05, significantly different from c-Jun-transfected and acrolein-treated cells (one-way ANOVA followed by the Tukey test).