Cellular senescence as a quality parameter in chronological aging

Abstract

Chronological aging and its difference with biological aging have been the subject of study for many years, trying to define within biological aging the causes or pathways by which this process of homeostatic deterioration occurs. Until the beginning of this year, 13 "Hallmarks of aging" have been defined, which describe the aging process from a molecular, cellular and systemic point of view, which are DNA instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, disabled macroautophagy, chronic inflammation, and dysbiosis. When conducting research on each of them, our attention was drawn to the close relationship between all of them and cellular senescence as a result of most of these processes. Cellular senescence refers to an irreversible form of long-term arrest of the cell cycle, which causes a loss of the ability to participate in tissue repair, in addition to damage caused through the secretion of senescence-associated secretory phenotype (SASP), which is closely linked to all known processes of biological aging. In this article we describe what cellular senescence is, what are the different processes or "Hallmarks" of aging currently defined, and their close relationship with cellular senescence. In addition, we took different approach to senescence to use it as a quality metric in chronological aging, instead of using it to define a biological age as it has been approached in the past.