Influence of Apolipoprotein E3 on the Production of Paired Helical Filament in Guamanian Parkinsonism‐dementia Complex/Amyotrophic Lateral Sclerosis and Alzheimer's Disease

Abstract

Background: Neuropathologically, Guamanian parkinsonism‐dementia complex (PDC) and amyotrophic lateral sclerosis (ALS) are characterized by neuronal loss and neurofibrillary tangles (NFTs). The NFTs are principally composed of paired helical filaments (PHFs) consisting of hyperphosphorylated tau and have been shown to be histopathologically similar to those in Alzheimer's disease (AD). Recent biochemical studies have suggested that the binding of apolipoprotein E3 (ApoE3) to tau may interfere with the hyperphosphorylation of tau, thus resulting in neuroprotective effects. Methods: In order to clarify the influence of ApoE3 on the production of PHFs in various pathological conditions, the ɛ3 allele frequency in patients with Guamanian PDC and ALS, as well as AD, was examined. Results: The results obtained in this study showed no significant differences between these affected groups and each of the controls in terms of the frequency of the ApoE3 allele. Conclusion: Although ApoE3 has been implicated in the production of PHFs, the present study suggests that ApoE3 may not have a strong inhibitory effect on the production of NFTs in these affected patients.