Cholesterol prevents Alzheimer's

Blood vessels work best when they are clear of cholesterol. But neurons need cholesterol to maintain top form, according to Abad-Rodriguez et al. (page 953). With too little of this membrane lipid, neurons produce more of the Alzheimer's-associated amyloid peptide (Aβ). The results are a warning that the effects of cholesterol-lowering drugs may need to be confined to the liver, where circulating sterols and fatty acids are made.

Aβ production begins when the APP precursor protein is cleaved by the BACE1 β-secretase. The new results show that cholesterol limits this cleavage by keeping BACE1 from its substrate. Most APP was found in cholesterol-free detergent-soluble domains, in which only ∼10% of the total APP was found in contact with BACE1. Much of the BACE1 was instead found in separate cholesterol-rich...