Figure 3.

Cholesterol depletion inhibits production and secretion of Aβ. Hippocampal neurons were grown for 4 days in the presence (+) or absence (−) of lovastatin/mevalonate and after infection with SFV/APP were treated with 5 mM methyl-β-cyclodextrin for the indicated times (min) and metabolically labeled for 2.5 hr. Cholesterol was added back for the indicated times (min) as a cholesterol-methyl-β-cyclodextrin inclusion complex (CD-cholesterol). (A) Aβ secreted from control and cholesterol-depleted cells (immunoprecipitated using antibody B7/6). (B) Aβ secreted from cholesterol-depleted/repleted cells. (C) Aβ secretion in cholesterol-depleted cells as compared with untreated control cells (mean of 3–11 experiments). (D) Immunoprecipitation of APP and its proteolytic fragments from cell homogenates using antibody B12/4. Fragments generated by α- and β-cleavage are indicated.