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 circulating FFA, cholesterol and TG concentrations were not different between H-apoD Tg and WT mice [15] . The mRNA expression of two enzymes implicated in lipoprotein metabolism, lipoprotein lipase (LPL) and hepatic lipase (HL) remained also unaffected in Tg mice (Data not shown). In contrast, the expression of CD36, a target of PPARγ and the main transporter of hepatic FFA in cells, was significantly increased (1.2-fold) in the liver of Tg mice (Fig 3A) . To evaluate the effect of elevated CD36 expression on hepatic FA uptake in Tg mice, we prepared primary hepatocytes from both WT and Tg animals. Incubation of cells with 3 H-oleate showed a 30% increase in oleate uptake in Tg mice (Fig 3B) . This confirmed that the upregulation of CD36 provides a functional role in those mice.