Figure 7

Platelet-activating factor (PAF)-mediated hydrolysis of cholesterol esters stabilizes amyloid-beta (Aβ)-containing lipid rafts. Schematic demonstrating the putative mechanism regulating the formation of Aβ-containing rafts. In this theory, Aβ₄₂ activates cPLA₂, resulting in the production of PAF. PAF activates cholesterol ester hydrolase (CEH) and the release of cholesterol from stores of cholesterol esters, which stabilizes Aβ₄₂ in rafts. Inhibition of cPLA₂ (arachidonyl trifluoromethyl ketone, or AACOCF₃), antagonism of the PAF receptors (Hexa-PAF), or inhibition of CEH (diethylumbelliferyl phosphate, is DEUP) reduces the cholesterol concentrations in the endoplasmic reticulum (ER). cPLA₂, cPLA2 is cytoplasmic phospholipase A₂; Hexa-PAF, 1-O-hexadecyl-2-acetyl-sn-glycerol-3-phospho-(N,N,N-trimethyl)-hexanolamine.