Sirtuins as Possible Predictors of Aging and Alzheimer's Disease Development: Verification in the Hippocampus and Saliva.

Verification of signaling molecules in the saliva is a non-invasive method of diagnosis and evaluation of treatment effectiveness in different pathologies. Sirtuins (SIRT), proteins from NAD-dependent histone deacetylases, are supposed to be involved in the pathogenesis of Alzheimerэs disease. Age-related decrease in sirtuins expression induces many pathophysiological processes that could lead to neurodegeneration. We studied the expression of SIRT1, SIRT3, SIRT5, and SIRT6 in the hippocampus and saliva of humans without neurological pathologies and in patients with Alzheimer's disease of elderly and senile age. In elderly and senile patients, the expression of SIRT1, SIRT3, and SIRT6 in the hippocampus and saliva was 1.5-4.9-fold reduced in comparison with healthy individuals of the corresponding age. In healthy senile persons, the expression of SIRT6 in the hippocampus and saliva was 2.5-4.5-fold lower than in healthy elderly individuals. Measurement of SIRT1, SIRT3, and SIRT6 concentration in the saliva can be used as an additional method for intravital non-invasive diagnosis of Alzheimer's disease in patients of advanced age. SIRT6 concentration in the saliva can be recommended as a marker for assessment of the rate of aging.