Although macrophage phagocytoses modified low-density lipoprotein (LDL), excessive accumulation of modified LDL induces macrophage foam cell formation, which is a feature of atherosclerotic plaque. Thus, the identification of scavenger receptor for modified LDL will provide better understanding of an atherosclerotic event. We recently showed that nucleolin expressed on macrophages acts as a scavenger receptor for various endogenous discarded products. Here, we investigated whether or not nucleolin is involved in the uptake of acetylated LDL (AcLDL). In contrast to normal LDL, AcLDL directly bound to immobilized nucleolin. AcLDL exhibited a higher affinity for macrophages than normal LDL. This binding of AcLDL was inhibited by anti-nucleolin antibody and antineoplastic guanine-rich oligonucleotide (AGRO), a nucleolinspecific oligonucleotide aptamer. In addition, AcLDL exhibited a higher affinity for HEK cells transfected with nucleolin than those without. Further, intracellular accumulation of AcLDL was also inhibited by antinucleolin antibody. The results of this study suggest that nucleolin expressed on macrophages is a receptor for AcLDL.Key words nucleolin; macrophage; acetylated low-density lipoprotein (AcLDL); scavenger receptor Low-density lipoprotein (LDL) elevates cholesterol deposits in macrophage foam cells, which are involved in the development of atherosclerotic lesions.1) As the uptake of normal LDL via its receptor is controlled by feedback regulation, excess levels of LDL-derived cholesterol in macrophages might be attributed to modifications of LDL such as oxidation, acetylation, and aggregation.2) Scavenger receptors (SRs) and other unknown receptors account for up to 95% of the uptake of modified LDL.