Increased expression of the amyloid precursor β-secretase in Alzheimer's disease

β-Secretase cleavage represents the first step in the generation of Aβ polypeptides and initiates the amyloid cascade that leads to neurodegeneration in Alzheimer's disease. By comparative Western blot analysis, we show a 2.7-fold increase in protein expression of the β-secretase enzyme BACE in the brain cortex of Alzheimer's disease patients as compared to age-matched controls. Similarly, we found the levels of the amyloid precursor protein C-terminal fragment produced by β-secretase to be increased by nearly twofold in Alzheimer's disease cortex.