Scavenger receptor-mediated adhesion of microglia to beta-amyloid fibrils.

A pathological hallmark of Alzheimer's disease is the senile plaque, containing beta-amyloid fibrils, microglia and astrocytes. Beta-amyloid fibrils exert a cytotoxic effect on neurons, and stimulate microglia to produce neurotoxins, such as reactive oxygen species. Mononuclear phagocytes, including microglia, express scavenger receptors that mediate endocytosis of oxidized low-density lipoproteins, and adhesion to glucose-modified extra-cellular matrix proteins. Here we report that class A scavenger receptors mediate adhesion of rodent microglia and human monocytes to beta-amyloid fibril-coated surfaces leading to secretion of reactive oxygen species and cell immobilization. Thus, class A scavenger receptors are potential therapeutic targets in Alzheimer's disease.