Pathobiology of aging: An introduction to age-related diseases

Abstract The aging process is considered a universal and inevitable process of physiological decline associated with a greater vulnerability to disease and death. Efforts to understand aging have suggested the need to distinguish aging from age-related diseases. However, in our opinion, we do not need to distinguish between aging and age-related diseases because, in protected environment, humans and animals die from age-related diseases, which are manifestations of aging. A series of critical questions have arisen in the field of aging regarding the physiological sources of aging-causing damage, the compensatory responses that try to re-establish homeostasis, the interconnection between the different types of damage and compensatory responses, and the possibilities to intervene exogenously to delay aging. So, we discuss the so-called cellular and molecular hallmarks of aging. The hallmarks and their interconnectivity should serve as an evaluation tool to assess and prioritize interventions that can be deemed effective in slowing aging and preventing age-related diseases. At the end of the paragraphs on hallmarks of aging, cancer will be treated as a model of age-related disease, since it is a paradigmatic example of the convergent or divergent role of hallmarks in disease and aging. Addressing the various mechanisms of aging and age-related diseases, we have discussed possible therapeutic interventions.