Aging is the inevitable fate of life. It is a natural process characterized by progressive functional impairment and reduced capacity to respond adaptively to environmental stimuli. The aging process, among other factors, determines the life span of an organism, whereas age-associated abnormalities account for the health status of a given individual. Aging is associated with increased susceptibility to a variety of chronic diseases, including type 2 diabetes mellitus, cancer, and neurological diseases. Lung pathologies are no exception, and the incidence and prevalence of chronic lung diseases has been found to increase considerably with age. Aging has various faces, and most importantly, it has no purpose. Age-related pathologies are believed to result from the accumulation of molecular and cellular damage that cannot be repaired by aged cells due to limited performance of somatic maintenance and repair mechanisms. Two major hypotheses provide a conceptual framework for aging. According to the antagonistic pleiotropy hypothesis by Williams (Evolution, 1957), natural selection favors genes that are beneficial early in life for the cost that they may promote aging later in life. The disposable soma theory put forward by Kirkwood (Nature, 1977) proposes that the organism optimally allocates its metabolic resources, chiefly energy, to maximize reproduction, fitness, and survival. This comes at the cost of limited resources for somatic maintenance and repair causing accumulation of molecular and cellular damage. This concept supports the observation that the aging process is stochastic in nature and that there is individual plasticity.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)