The link between low PPARα-activity in Cyp1b1-ko mice and lipid droplet depletion is further established by several gene expression decreases that are conserved in male and female mice. These include CD36 (membrane transfer of fatty acids) [43], Vldlr (triglyceride uptake) [47], Cidec (lipid droplet stabilization) [48] and G0s2 (Pnpla triglyceride lipase inhibitor) [51] (Table 2). The decline of Igfbp1 in Cyp1b1-ko mice releases of sequestered IGF1, which then stimulates glucose uptake [63]. The conserved stimulation of adropin mRNA, when reproduced by a transgene, recapitulates many of the changes seen in Cyp1b1-ko mice [66] and also targets endothelial functions [80]. The strong correlation between the increased adropin and Cyp7b1 expression across treatment groups for both males and females (Figure 7A) may reflect their shared suppression by LXR activity, which could also be suppressed in Cyp1b1-ko mice.
