Fig. 9
A simplified scheme of p53 activity and chromatin modifiers in the aging lung. p53 plays a central role in cellular senescence and reactive oxygen species (ROS) induced cellular stress. This stimulates p53 dependent activation of antioxidant defense genes. Telomere shortening leads to replicative senescence, DNA damage response (DDR) and cellular aging. Telomerase reverse transcriptase (Tert) restores telomere length following end capping. Senescent cells secrete a range of pro-inflammatory molecules subsumed under the so-called senescence-associated secretory phenotype (SASP)