Abstract

Aging is a natural, highly complex, and heterogenous process involving progressive loss of physiological functioning and a deficiency in cellular homeostasis. Aging is the highest risk factor for developing chronic pathologies. Hallmarks of aging include downregulation of metabolic anti-aging or prolongevity pathways—AMP-activated protein kinase and silencing information regulator 2 related enzyme 1—and upregulation of the proaging mammalian target of rapamycin and insulin/IGF-1 pathways; loss of mitochondrial function, proteostasis, and stem cell regenerative capacity; persistent and uncontrolled production of senescence-associated secretory phenotype reactive oxygen species and proinflammatory molecules, telomere erosion, chromatin and epigenetic alterations, and lost RNA quality control. This chapter summarizes how the aforementioned molecular and cellular DNA, RNA, and protein mechanisms contribute to aging.