CD36 does not play a direct role in HDL or LDL metabolism

CD36 and scavenger receptor class B, type I (SR-Bl) are both class B scaven ger receptors that recognize a broad variety of ligands, including oxidized low density lipoprotein (oxLDL), HDL, anionic phospholipids, and apoptotic cells. In this study we investigated the role of mouse CD36 (mCD36) as a p hysiological lipoprotein receptor. We compared the association of various l ipoprotein particles with mCD36 and mSR-BI expressed in COS cells by adenov irus-mediated gene transfer. mCD36 bound human oxLDL and mouse HDL with hig h affinity. Human LDL bound poorly to mCD36, indicating that mCD36 is unlik ely to play a significant role in LDL metabolism. The ability of mCD36 to m ediate the selective uptake of cholesteryl esters (CE) from receptor-bound HDL was assessed. In comparison with mSR-BI, mCD36 inefficiently mediated t he selective uptake of CE. Hepatic overexpression of mCD36 in C57BL/6 mice by adenovirus-mediated gene transfer did not result in significant alterati ons in plasma LDL and HDL levels.ie We conclude that mCD36, while able to b ind HDL with high affinity, does not contribute significantly to HDL or LDL metabolism.