Co-localization of cholesterol, apolipoprotein E and fibrillar Aβ in amyloid plaques

Recent evidence strongly suggests a role for cholesterol and apolipoprotein E in the etiology of Alzheimer's disease. We have demonstrated the co-localization of cholesterol and apolipoprotein E with P-amyloid immunoreactivity and thioflavin S immunofluorescence in AD type plaques of a transgenic mouse model. Cholesterol and apolipoprotein E co-localized to the core of thioflavin S-positive (fibrillar) plaques, but not thioflavin S-negative (diffuse) plaques from an early age. By 18 months of age, there was extensive coverage of fibrillar plaques immunopositive for apolipoprotein E and cholesterol oxidase. These findings support evidence that cholesterol and apolipoprotein E are involved in fibrillar plaque formation or maintenance, and suggest that cholesterol may impact amyloid formation extracellularly, as well as through an intracellular effect. (C) 2002 Elsevier Science B.V. All rights reserved.