Caspase Cleaved Tau in Alzheimer's Disease: A Therapeutic Target Realized.

Abstract

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by an array of symptoms affecting memory and cognition. Some common symptoms of AD include memory loss that disrupts daily life, challenges in planning or solving problems, confusion with time or place, and changes in mood and personality [1]. Central dogma to the etiology of AD is the beta-amyloid cascade, which stipulates that beta-amyloid in oligomeric forms represents the earliest step in a cascade eventually leading to the formation of senile plaques and neurofibrillary tangles (NFTs) and neurodegeneration [2]. For many years the connection between plaques and tangles was unknown, however, in 2002 we reported that caspase activation and the cleavage of tau might link these two molecular entities in AD [3]. Our evidence was based on the synthesis and application of a caspase-cleavage site directed antibody to a known caspase-cleavage site within tau located at the amino-terminus (position 25). Figure 1 depicts the first experiment ever performed with affinity-purified tau caspase-cleavage antibody that revealed widespread labeling predominantly within NFTs, neuropil threads, and dystrophic neurites (Figure 1A) that was absent in age-matched control sections (Figure 1B).