High-Fat Diets and LXRs Expression in Rat Liver and Hypothalamus

Disturbances on lipid metabolism are associated with health disorders. High-fat diets (HFDs) consumption promotes cardiovascular and neurodegenerative diseases where cholesterol plays an important role. Among regulators of this steroid homeostasis, the liver X receptors (LXRs) induce genes that protect cells from cholesterol overload. We previously described how both hypothalamic LXRα and LXRβ are sensitive to a high-fructose diet, suggesting that these receptors trigger responses related to control of energy and food intake. The present work's main objective was to study the effect of different HFDs on LXRs expression (in hypothalamus and liver), and lipid profile. Male rats received control diet (CD), HFD₁ (CD + bovine fat (BF)), HFD₂ (CD + BF + cholic acid (CA)), HFD₃ (CD + BF + cholesterol), or HFD₄ (CD + BF + CA + cholesterol) for different time periods. Hypothalamic LXRβ, both hepatic LXRs subtypes, and total cholesterol (TC) raised after 2 weeks of HFDs. Four and 8 weeks of HFD₃ and HFD₄ increased the LXRs subtypes in both tissues and TC levels. Only HFD₄ reduced triglycerides (TG) levels after 2 and 8 weeks. The TC and TG values correlated significantly with LXRs expression only in rats fed with HFD₄. These data add relevant information about how diet composition can produce different scales of hypercholesterolemia states accompanied with central and peripheral changes in the LXRs expression.