Accumulation of senescent cells in mitotic tissue of aging primates

• Published in: Mechanisms of ageing and development Vol. 128; no. 1; pp. 36 - 44
• Main Authors: Jeyapalan, Jessie C., Ferreira, Mark, Sedivy, John M., Herbig, Utz
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-01-2007; Elsevier Science
• Subjects: Aging; Aging - physiology; Animals; Biological and medical sciences; Cells, Cultured; Cellular Senescence - physiology; Development. Metamorphosis. Moult. Ageing; DNA damage; Fibroblasts - cytology; Fibroblasts - physiology; Fundamental and applied biological sciences. Psychology; Mitosis - physiology; p16; p21; Papio; Senescence; Telomeres; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Aging; Telomeres; Senescence; p16; DNA damage; p21; Ageing; Telomere; Tissue; Vertebrata; Mammalia; DNA; Primates; Biological accumulation
• ISSN: 0047-6374; 1872-6216
• DOI: 10.1016/j.mad.2006.11.008

Cellular senescence, a stress induced growth arrest of somatic cells, was first documented in cell cultures over 40 years ago, however its physiological significance has only recently been demonstrated. Using novel biomarkers of cellular senescence we examined whether senescent cells accumulate in tissues from baboons of ages encompassing the entire lifespan of this species. We show that dermal fibroblasts, displaying markers of senescence such as telomere damage, active checkpoint kinase ATM, high levels of heterochromatin proteins and elevated levels of p16, accumulate in skin biopsies from baboons with advancing age. The number of dermal fibroblasts containing damaged telomeres reaches a value of over 15% of total fibroblasts, whereas 80% of cells contain high levels of the heterochromatin protein HIRA. In skeletal muscle, a postmitotic tissue, only a small percentage of myonuclei containing damaged telomeres were detected regardless of animal age. The presence of senescent cells in mitotic tissues might therefore be a contributing factor to aging and age related pathology and provides further evidence that cellular senescence is a physiological event.