Telomerase and telomeres in aging theory and chronographic aging theory (Review)

Abstract

The current review focuses on the connection of telomerase and telomeres with aging. In this review, we describe the changes in telomerase and telomere length (TEL) during development, their role in carcinogenesis processes, and the consequences of reduced telomerase activity. More specifically, the connection of TEL in peripheral blood cells with the development of aging‑associated diseases is discussed. The review provides systematic data on the role of telomerase in mitochondria, the biology of telomeres in stem cells, as well as the consequences of the forced expression of telomerase (telomerization) in human cells. Additionally, it presents the effects of chronic stress exposure on telomerase activity, the effect of TEL on fertility, and the effect of nutraceutical supplements on TEL. Finally, a comparative review of the chronographic theory of aging, presented by Olovnikov is provided based on currently available scientific research on telomere, telomerase activity, and the nature of aging by multicellular organisms.

Keywords: chronomere; stem cells; telomerase; telomere; theory of aging.

Figure 1.

Schematic representation of the interaction of the telomeric complex (comprised of TRF1, TRF2) with a part of telomeric DNA. Protein components include p95, p23 and ТР1 proteins, as well as the catalytic subunit hTERT, which performs the synthesis of telomeric repeats. Moreover, tankyrase PARP is depicted to also interact with the telomeric complex. TRF, telomeric repeat binding factor; hTERT, human telomerase reverse transcriptase; PARP, poly (ADP)-ribose polymerase.