Figure 4.

Retinoic acid receptor (RAR)α transactivation response to retinoic acid (RA) and apocarotenoids in monkey kidney fibroblasts. Cells transfected with RARα receptor vector were treated for 22–24 h with an apocarotenoid concentration of 10⁻⁵ mol/L; the bars from left to right indicate the effects on RARα of RA, apo-14′-CA, apo-8′-CA, β-ionone, β-cyclocitral, β-ionylideneacetic acid and C13 ketone, respectively. At concentrations of 10⁻⁶ mol/L, the effects on RARα of RA, apo-8′-CA, apo-14′-CA and C13 ketone were shown by the bars from left to right, respectively. Luciferase activities were measured by dual-luciferase reporter system and were expressed as fold induction in treated cells (see Materials and methods). Data are expressed as the mean ± SD or range from multiple experiments as indicated (n) with three independent observations per experiment. If no ‘n’ is indicated the experiment was conducted once in triplicate