Cellular senescence and tissue aging in vivo.
A long-standing controversy concerns the relevance of cellular senescence, defined and observed as a cell culture phenomenon, to tissue aging in vivo. Here the evidence on this topic is reviewed. The main conclusions are as follows. First, telomere shortening, the principal known mediator of cellular senescence, occurs in many human tissues in aging. Second, it is not clear whether this results in cellular senescence or in some other cell fate (e.g., crisis). Third, rodents probably are not appropriate experimental models for these questions, because of important differences in telomere biology between rodent cells and cells from long-lived mammals (e.g., human or bovine cells). Fourth, better and more comprehensive observations on aging human tissues are needed to answer the question of the occurrence of senescent cells in tissues, and new experimental approaches are needed to elucidate the consequences of telomere shortening in tissues in aging.
Hornsby
Peter J
PJ
Department of Physiology and the Sam and Ann Barshop Center for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio 78245, USA. hornsby@uthscsa.edu
D000818:Animals; D018929:Cell Culture Techniques; D002455:Cell Division; D016922:Cellular Senescence; D004268:DNA-Binding Proteins; D006801:Humans; D051379:Mice; D019098:Telomerase / Q000378:metabolism; D016615:Telomere
D004268:DNA-Binding Proteins; D019098:Telomerase