Sirtuins Expression in the Hippocampus and Buccal Epithelium of Elderly and Senile Individuals with Alzheimer’s Disease

Sirtuins (SIRT) are a class of NAD-dependent proteins with deacetylase activity that are involved in the regulation of transcription, metabolic pathways, and cell aging via the deacetylation of histone and nonhistone targets. It was hypothesized that sirtuins play important role in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD). An age-related decrease in sirtuin expression leads to oxidative stress, which can cause neurodegeneration. This article examines the age-related dynamics of SIRT1, 3, 5, and 6 expression in patients with AD and in healthy individuals with immunohistochemistry and immunocytochemistry methods via immunofluorescent confocal microscopy. In elderly and senile health individuals, the SIRT1, 3, 5, and 6 expression in the hippocampus and buccal epithelium did not differ significantly. In AD patients, the SIRT1, 3, 5, and 6 expression in the hippocampus and buccal epithelium decrease by 1.5–5 times as compared with healthy elderly and senile individuals. The SIRT5 expression in the hippocampus and buccal epithelium does not depend on the age or AD diagnosis. Thus, the SIRT 1, 3, and 6 expression in the buccal epithelium can be a marker for intravital, noninvasive AD diagnosis in elderly and senile individuals.