Impacts of Membrane Biophysics in Alzheimer's Disease: From Amyloid Precursor Protein Processing to AβPeptide-Induced Membrane Changes

Abstract

An increasing amount of evidence supports the notion that cytotoxic effects of amyloid-βpeptide (Aβ), the main constituent of senile plaques in Alzheimer's disease (AD), are strongly associated with its ability to interact with membranes of neurons and other cerebral cells. Aβis derived from amyloidogenic cleavage of amyloid precursor protein (AβPP) byβ- andγ-secretase. In the nonamyloidogenic pathway, AβPP is cleaved byα-secretases. These two pathways compete with each other, and enhancing the non-amyloidogenic pathway has been suggested as a potential pharmacological approach for the treatment of AD. Since AβPP,α-,β-, andγ-secretases are membrane-associated proteins, AβPP processing and Aβproduction can be affected by the membrane composition and properties. There is evidence that membrane composition and properties, in turn, play a critical role in Aβcytotoxicity associated with its conformational changes and aggregation into oligomers and fibrils. Understanding the mechanisms leading to changes in a membrane's biophysical properties and how they affect AβPP processing and Aβtoxicity should prove to provide new therapeutic strategies for prevention and treatment of AD.