Effect of phytoceramide on PPAR activity in the Gal4/PPAR chimera system. The expression vector for PPAR LBD/Gal4 DBD and Gal4 UAS luciferase reporter were transfected into NIH/3T3 cells. After 24 h, cells were treated with phytoceramide at the indicated concentrations. The luciferase assay was performed as described in the legend to Figure 2A. All results are shown as means ± S.D. (n = 3). *P < 0.05, ***P < 0.001, significantly different from the level of vehicle control.