Our single 48 hour treatment with Wy-14,643 produced fewer responses than the standard two week multi-treatment protocol or a 6 hour acute stimulation [57–58]. However, 23 genes responded to Wy-14,643 in the opposing direction as the differential expression between Cyp1b1-ko and WT mice (Table 3). This includes 5 genes that were suppressed by Wy-14,643 treatment, but exhibited elevated expression in Cyp1b1-ko mice. Remarkably, the WT Wy-14,643 responses were highly correlated with suppression of constitutive expression in Cyp1b1-ko mice (r2=0.72) (Figure 6C). In addition, 8 genes that exhibited a large suppression response to Cyp1b1 deletion responded to chronic PPARα activation in the opposite direction [44], even though unresponsive to our 48 hour Wy-14,643 exposure. Accordingly, Cidec, G0s2, Pdk4 and Igfbp1 are stimulated by Wy-14,643 with these alternative protocols [57], wherein the single oral gavage of Wy-14,643 is more effective after 6 hours than after the 48 hours used here. Conversely, Cyp4a and CD36 gene stimulations are greater under our 48 hour treatment strategy.
