Engagement of the scavenger receptor is not responsible for β-amyloid stimulation of monocytes to a neurocytopathic state

Experiments were performed to determine if scavenger receptors (SRs) play a role in amyloid beta (AP) stimulation of peripheral blood monocyte (PBM) neurotoxicity. Results indicate that AP does not block binding of the SR ligand DiI-acetylated low density lipoprotein to PBM, nor does another SR ligand, fucoidin, inhibit AP-PBM binding. Moreover, neither of three SR ligands alone stimulates neurotoxicity in PBM, nor antagonizes the ability of AP to activate PBM to a neurocytopathic state. Such findings suggest that Ap's action is not dependent upon engagement of the SR ligand binding domain and raise doubts about the role of SR in AP neurotoxicity. (C) 2000 Academic Press.