Cellular Senescence in Age-Related Macular Degeneration: Can Autophagy and DNA Damage Response Play a Role?

Figure 3

Senescent cells and senescence-associated secretory phenotype (SASP). A cell undergoing senescence is permanently arrested in the G1 or G2 phase of the cell cycle and has changed morphology. It is featured by an increased activity of senescence-associated-β-galactosidase (SA-β-gal) and can be targeted by the immunological system, with natural killer (NK) cells, macrophages (MS), and T-lymphocytes involved. Released various soluble agents, including cytokines, chemokines, growth factors, and extracellular vesicles, are main determinants of SASP. A senescent cell is characterized by an elevated level of DNA damage and chromosomes aberrations, which are also signs of genomic and chromosomal instability, typical for cancer cells. Chemokine signaling through the CXCR2 protein increases senescence.