Gene expression against DNA methylation: Comparative Analysis of Approaches to the Assessment of Biological Aging

In this paper, a comparative analysis of two fundamentally different methodological approaches to the assessment of biological aging is carried out: epigenetic clocks based on the analysis of DNA methylation, and transcriptomic clocks based on the analysis of gene expression. It is shown that epigenetic clocks, despite their wide use and commercial availability, have fundamental limitations: they measure stable epigenetic modifications that do not reflect the current functional state of the cell, and the results of their use significantly depend on the type of tissue. Transcriptomic clocks, on the contrary, record the real activity of genes at the time of analysis, which provides a direct connection with the functional mechanisms of aging and allows them to be used to assess the effects of preventive and therapeutic interventions. Arguments are given in favor of the fact that it is the transcriptomic approach that is a scientifically grounded tool for subsequent comparison and personalized management of aging processes.