[HTML][HTML] Macrophage scavenger receptor CD36 is the major receptor for LDL modified by monocyte-generated reactive nitrogen species

EA Podrez, M Febbraio, N Sheibani… - The Journal of …, 2000 - Am Soc Clin Investig
EA Podrez, M Febbraio, N Sheibani, D Schmitt, RL Silverstein, DP Hajjar, PA Cohen…
The Journal of clinical investigation, 2000Am Soc Clin Investig
The oxidative conversion of LDL into an atherogenic form is considered a pivotal event in
the development of cardiovascular disease. Recent studies have identified reactive nitrogen
species generated by monocytes by way of the myeloperoxidase-hydrogen peroxide-nitrite
(MPO-H2O2-NO2–) system as a novel mechanism for converting LDL into a high-uptake
form (NO2-LDL) for macrophages. We now identify the scavenger receptor CD36 as the
major receptor responsible for high-affinity and saturable cellular recognition of NO2-LDL by …
The oxidative conversion of LDL into an atherogenic form is considered a pivotal event in the development of cardiovascular disease. Recent studies have identified reactive nitrogen species generated by monocytes by way of the myeloperoxidase-hydrogen peroxide-nitrite (MPO-H2O2-NO2) system as a novel mechanism for converting LDL into a high-uptake form (NO2-LDL) for macrophages. We now identify the scavenger receptor CD36 as the major receptor responsible for high-affinity and saturable cellular recognition of NO2-LDL by murine and human macrophages. Using cells stably transfected with CD36, CD36-specific blocking mAbs, and CD36-null macrophages, we demonstrated CD36-dependent binding, cholesterol loading, and macrophage foam cell formation after exposure to NO2-LDL. Modification of LDL by the MPO-H2O2-NO2 system in the presence of up to 80% lipoprotein-deficient serum (LPDS) still resulted in the conversion of the lipoprotein into a high-uptake form for macrophages, whereas addition of less than 5% LPDS totally blocked Cu2+-catalyzed LDL oxidation and conversion into a ligand for CD36. Competition studies demonstrated that lipid oxidation products derived from 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphocholine can serve as essential moieties on NO2-LDL recognized by CD36. Collectively, these results suggest that MPO-dependent conversion of LDL into a ligand for CD36 is a likely pathway for generating foam cells in vivo. MPO secreted from activated phagocytes may also tag phospholipid-containing targets for removal by CD36-positive cells.
The Journal of Clinical Investigation