Biological aspects of longevity and ageing
Kappeler, L.; Epelbaum, J.
Revue d'Epidemiologie et de Sante Publique 53(3): 235-241
2005
ISSN/ISBN: 0398-7620 PMID: 16227910 Document Number: 589093
This paper summarizes 3 types of recent developments on aging research: (1) A consensus on evolutionist theory of aging is developing. This theory is based on the fact that long-lived species usually arise from protected ecological niches. It implies that phenotypes which are expressed late in "aged survivors" are beyond natural selection. Alleles underlying this late expression being adoptive or not ("good" or "bad"), contribute only slightly to the pool of genes of the following generation; (2) Study of laboratory models like the nematode C. elegans or fly D. melanogaster have enabled the observation that single-gene invalidation can increase lifespan. Interestingly, some of these changes seem to imply a common process through insulin/insulin-like growth factor 1 (IGF-1) orthologue, energy metabolism and growth implicated hormones, as well as protection against free radicals; (3) In the mouse, several genes mutation increase lifespan and are associated with a decrease in growth hormone secretion, as well as its main effector IGF-1. The study of such transgenic mutants, in parallel with the well-known effect of the caloric restriction on aging, open several tracks which should allow determining common mechanisms which regulate the mammalian lifespan.