Cellular aging

Senescence is defined as cellular ageing resulting in an irreversible cell cycle arrest. Primary cells divide about 50 times and then are arrested due to senescence. Senescence is associated with shortening of telomeres. 

The events which occur prior to the death of short-term cultures have been referred to as the process of cellular aging, or apoptosis. Whether in vitro cellular aging is due to an inherited genetic program, or whether in vitro aging is simply a consequence of an imperfect cell culture environment is a matter of controversy. The possibility that the cellular aging which occurs in vitro resembles cellular aging in vivo is unresolved. 

E. A. Ross, N. Anderson, and H. S. Micklem, Serial depletion and regeneration of the murine hematopoietic system. Implications for hematopoietic organization and the study of cellular aging, J.Exp.Med. 155(2), 432-444 (1982). 

Boveris A, Costa LE, Cadenas E. 1999. The mitochondrial production of oxygen radicals and cellular aging. In Cadenas E, Packer L, Eds. Understanding the Process of Aging—The Role of Mitochondria, Free Radicals and Antioxidants. New York Marcel Dekker, Inc pp. 1-16. 

Bosnian GJ, Bartholomeus IG, de Man AJ, van Kalmthout PJ, de Grip WJ. Erythrocyte membrane characteristics indicate abnormal cellular aging in patients with Alzheimer s disease. Neurobiol Aging 1991 12(1) 13 18. 

B30. Brunk, U. T., Jones, C. B., and Sohal, R. S., A novel hypothesis of lipofuscinogenesis and cellular aging based on interactions between oxidative stress and autophagocytosis. Mutat. Res. 275, 395 103 (1992). 

Riabowol K, Schiff J, Gilman MZ. Transcription factor AP-1 activity is required for initiation of DNA synthesis and is lost during cellular aging. Proc. Natl. Acad. Sci. U.S.A. 1992 89 157-161. 

Flood MT, Haley JE, Gouras P. 1984. Cellular aging of human retinal epithelium in vivo and in vitro. Monogr Dev Biol 17 80-93. 

In smears, the nuclear chromatin appears to be clumped and the nucleus exhibits two, three, or four segments. A higher number of segments is considered to he a sign of cellular aging or of a congenital anomaly. Nucleoli are absent (D4). 

Finally, we discuss the use of metal ions In probing cellular age changes, whether or not these changes were Induced by metal Ions. 

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