Fig. 6.

Heat map summary of the gene expression profile for the antioxidant signaling pathway following the treatment of keratinocytes by novel derivatives of vitamin D₃ or lumisterol. Keratinocytes were pretreated with the indicated hydroxy-derivatives of vitamin D₃ or lumisterol (100 nM), or ethanol vehicle, for 24 h before UVB irradiation (50 mJ/cm²) then further incubated with the same hydroxy-derivative for an additional 24 h. Cells were lysed after treatment and total RNA extracted. Gene expression measurements were confirmed using quantitative real time PCR methods and expression levels normalized the relative to β-actin, cyclopilin, and GAPDH RNA. (A), Heat-maps of log2 transformed expression ratios for non-irradiated compared with UVB-irradiated (50 mJ/cm²) cells. (B), Irradiated cells pretreated with the hydroxyderivatives (or the ethanol vehicle). Each vertical row represents the same gene product and each horizontal row each sample. The fluorescence range from high (red) to low (blue) is indicated by the colored bar and reflects the degree of fluorescence intensity/gene expression. Data are presented as mean of fold-change (mean ± SD) calculated from the SYBR fluorescence intensities. The statistical significance of differences was evaluated by the student t-test, * P < 0.05, ** P < 0.01, *** P < 0.001 for all conditions.