EXPRESSION OF APOLIPOPROTEIN-E INHIBITS AGGREGATION OF THE C-TERMINALFRAGMENTS OF BETA-AMYLOID PRECURSOR PROTEIN

An important role of apolipoprotein E in the amyloidogenesis of Alzhei mer's disease is suggested by an accumulation of apolipoprotein E in b eta-amyloid plaques and a genetic association between Alzheimer's dise ase and one of the allelic variants (APOE4) of apolipoprotein E. Overe xpression of a C-terminal region of beta-amyloid precursor protein bri ngs about aggregation of the C-terminal fragments in COS cells. This C OS cell culture system was used to study effects of apolipoprotein E o n aggregation of the C-terminal fragments. When both apolipoprotein E and the C-terminal fragments were overexpressed in COS cells, Western blot analyses revealed significant inhibition of aggregation of the C- terminal fragments. No significant differences between apolipoprotein E3 and E4 in the inhibitory activities were found by this method. Apol ipoprotein E may inhibit formation of amyloid fibrils.