Accumulation of LOX-1 ligand in plasma and atherosclerotic lesions of Watanabe heritable hyperlipidemic rabbits: Identification by a novel enzyme immunoassay

LOX-1 (lectin-like oxidized LDL receptor) is a newly identified cell surfac e receptor for oxidized LDL mainly expressed in endothelial cells. Recombin ant soluble LOX-1(LOX-Fc) was generated by fusing the extracellular domain of LOX-1 with the Fc portion of IgG. A novel sandwich enzyme immunoassay sp ecific for LOX-1 ligand is designed, using LOX-Fc and anti-apoB antibody. T his immunoassay was used to determine LOX-1 ligand activity in normal and W atanabe heritable hyperlipidemic (WHHL) rabbit plasma. LOX-Fc was further a pplied for staining of atherosclerotic lesions of WHHL rabbits. LOX-I ligan d levels were significantly elevated in the plasma of hyperlipidemic rabbit s compared with controls. Furthermore, LOX-1 ligand activity was detected i n the atherosclerotic lesions in situ. These results support the potential roles of LOX-1 interacting with its ligand in the pathogenesis of atheroscl erosis, which is enhanced in hyperlipidemia. (C) 2001 Academic Press.