Apolipoprotein D Transgenic Mice Develop Hepatic Steatosis through Activation of PPAR? and Fatty Acid Uptake

Labrie, Marilyne; Lalonde, Simon; Najyb, Ouafa; Thiery, Maxime; Daneault, Caroline; Des Rosiers, Chrisitne; Rassart, Eric; Mounier, Catherine

We previously demonstrated that PPARα mRNA was increased in H-apoD Tg mice liver suggesting an elevated hepatic lipid β-oxidation [15] . A similar increase was observed at the protein level (2.73 fold) (Fig 5A) . Since PPARα is known to regulate the expression of genes involved in the β-oxidation pathway, we examined the expression of two key proteins involved in this process. The mRNA of PGC-1α, a co-activator of PPARα remained unchanged ( Fig 5B) . However, the mRNA expression of the carnitine palmitoyltransferase I (CPT-1), the rate limiting enzyme of the mitochondrial lipid transfer was slightly increased (1.26-fold) in the liver of H-apoD Tg mice compared to WT (Fig 5C) . This might be associated to a slight upregulation of lipid β-oxidation in the liver of H-apoD Tg mice.