Alterations in expression of TLR2 and TLR4 during successful and pathological aging

The generally accepted theory of aging is the theory of inflammaging. The leading role in its development is played by the mechanisms of innate immunity. Key receptors of innate immunity are TLRs. The patterns of age-related changes in the functioning of the TLR system remain the subject of study. The purpose of the work is to study the expression of TLR2 and TLR4 receptors in peripheral blood cells of centenarians and elderly people at the level of genes and surface molecules. The study analyzed the expression of genes and molecules TLR2 and TLR4 in young donors (n = 50), elderly people (n = 50) and centenarians (n = 100). Analysis of TLR2 and TLR4 gene expression was carried out using RT-PCR. Determination of surface expression of TLR2 and TLR4 was carried out using flow cytofluorimetry. This study is the first to analyze the age-related dynamics of expression of genes and molecules TLR2 and TLR4. It was revealed that in groups of elderly patients and long-livers, TLR2 expression is increased both at the gene and on the cell surface, compared to young donors. In contrast, TLR4 expression decreased with age. Studied groups of patients were divided depending on the aging phenotype into two subgroups: successful and pathological aging. In elderly individuals, TLR2 is increased in both phenotypes, while TLR4 is decreased in the pathological aging. In the group of centenarians with a pathological aging, a decrease in both TLR2 and TLR4 is observed, compared with young. In long-livers with successful aging, an increase in TLR2 expression was observed at the gene and protein level and TLR4 expression was comparable to the group of young individuals. Identified changes in the expression of TLR2 and TLR4, observed in different age groups, can be considered as markers of various aging phenotypes.