Fig. 2.

Effect of SAM treatment on DUSP1 expression in cultured hepatocytes. Mouse (A, B) or human (C, D) hepatocytes were treated with SAM (2 mM) for 2 or 12 hours. Where indicated, cells were pretreated with actinomycin D (Ac.D, 5 µg/mL) for 5 minutes. (A) Effect of SAM and actinomycin D treatment on DUSP1 mRNA levels in mouse hepatocytes measured by way of real-time PCR. Cells were pretreated with Ac.D for 5 minutes followed by Ac.D alone or with SAM (A+S) for another 2 hours. Results are expressed as fold of T0 cells (mean ± SEM) from three to five independent experiments. *P < 0.01 versus T0; **P < 0.001 versus T0 and UT at 2 or 12 hours; ^†P < 0.05 versus Ac.D alone. (B) Effect of SAM treatment on DUSP1 protein levels in cultured mouse hepatocytes on western blot analysis. Mouse hepatocytes were cultured and treated with SAM (2 mM) for 12 hours. When indicated, cells were pretreated with MG132 (20 µM) for 1 hour. Results are expressed as fold of T0 cells (mean ± SEM) from three independent experiments. *P < 0.001 versus T0; ^†P < 0.002 versus UT at 12 hours. (C) Effect of SAM treatment on DUSP1 mRNA levels in human hepatocytes. Results are expressed as fold of T0 cells (mean ± SEM) from three independent donors. *P < 0.0001 versus T0; ^†P < 0.02 versus UT at 12 hours. (D) Effect of SAM treatment on DUSP1 protein levels in human hepatocytes. Results are expressed as fold of T0 cells (mean ± SEM) from three independent donors. *P < 0.0001 versus T0; ^†P < 0.02 versus UT at 12 hours.