The Pparαhep−/− model was used to determine whether PPARα could drive hepatic regulations both in fasting-induced fatty acid catabolism as well as fatty acid anabolism during refeeding. The fasting–refeeding experimental design was validated by measuring glycaemia (figure 3A) and expression of fatty acid synthase (Fasn), which encodes the rate-limiting enzyme in lipogenesis (figure 3B). Both were low during fasting, intermediary in ad libitum-fed animals, and high in refed animals. Cyp4a14 (a well-known PPARα target) expression was low or undetectable in Pparαhep−/− animals, and strongly upregulated with fasting in WT mice (figure 3C).
