Plasma Lipid Profiles of Transgenic mice expressing the Human ApoB100XCETP are altered differentially by Diets enriched with defined Fatty Acids

Abstract

Dietary fat is known to modulate plasma lipid profiles. Synthesis of high density lipoproteins (HDL), which has protective effects on vascular disease is also influenced by dietary fats, but the mechanisms are unclear. The hapoB100XCETP transgenic mouse was used to investigate the effects of fatty acids on the metabolism of plasma lipoproteins, including the pathway leading to synthesis HDL. Male transgenic mice were fed with diets formulated to provide TG (33% energy) as tripalmitin (TP), triolein (TO), tristearin (TS) or equicaloric substitution of fat with carbohydrate (sucrose) for 4 weeks. Analysis of plasma profile showed that HDL-cholesterol were 53.7+14; 64.6+8.6; 50.2+3.3; 47.0+9.2 and 45.2+4.9 mg/dL for control, oleate, palmitate, stearate and sucrose based diets, respectively. LDL-cholesterol levels were 51.7+7.0; 23.1+7.0; 38.9+2.2; 75.1+1.8 and 46.8.1.0 mg/dl, for control, TO, TP, TS and sucrose, respectively. Hepatic Lecithin-cholesterol acyltransferase (LCAT) protein levels increased by 2-fold in mice fed TS or TO diets, compared to TP, while sucrose had no effect. The scavenger receptor class B type I (SR-B1) which plays an important role in meditating the uptake of HDL-derived cholesterol and cholesteryl ester in the liver and steroidogenic tissues increased in livers of animals fed TP and TO, while TS and sucrose did not have a similar effects. These results suggests that fatty acids can uniquely impact HDL, in addition, the ApoB100XCETP mouse is a useful model for the evaluation of how dietary components affect the risk of developing atherosclerosis and heart disease.