(A, B) In SH-SY5Y cells expressing wild-type AβPP, LDL (50 μg/ml for 3 days) treatment significantly increased secreted levels Aβ1–40 and Aβ1–42, as well as, intraneuronal levels of Aβ1–40 and Aβ1–42 (*p<0.05; **p<0.01; ***p<0.001 vs control; n=5). HDL (50 μg/ml for 3 days) treatment did not significantly increase secreted or intraneuronal levels of Aβ (n=5). (C) Neither LDL nor HDL affected protein levels of full-length AβPP. (D) LDL treatment, but not HDL, increased significantly protein levels of BACE1 (*p<0.05; n=4).