Biological Age Can Be Moved in Both Directions

There is a dynamic equilibrium between agingAging and rejuvenationRejuvenation factors. In agingAging organism, agingAging/rejuvenationRejuvenation ratio (rar) is > 1, whereas in rejuvenating organism rar < 1. The cell has remarkable potential of immortalityImmortality, unfortunately, not fully used in metazoans and humans. Stimulation of rejuvenationRejuvenation factors together with a gradual suppression of agingAging can be a robust strategy for rejuvenationRejuvenation (rar ≤ 1). Rejuvenology is a science with growing methodology and models. Biological clocks are one of them, allowing quantitatively assessing the efficiency of rejuvenationRejuvenation factors. There are at least a half-dozen agingAging clocks, of them, epigenetic clocks are the best known and most reliable. Methylation in selected sequences of DNA, known as epigenetic or biological aging clocksBiological aging clocks, can be used for estimation of biological ageBiological age and agingAging rate. This was shown in both human and animal studies. Epigenetic methylation clock is more sensitive to longevityLongevity and mortality, i.e. to biological ageBiological age, whereas transcriptomic, proteomic and metabolomic clocks show higher sensitivity to disease phenotypes.