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What is Senescence?
- Terminal decrepitude: what happens if we remain healthy throughout life. Nothing works like it used to. Nothing.
- Cells: loss of reversible quiescence, regenerative & reparative capability (gene de-repression p16INK4a) promotes either cell involution or growth (sometimes leading to cancer)
- Embryonic cells: tissues required for development senesce, die when done (tadpole's tail, umbilical cord); trigger of tissue remodeling
- Damaged cells: death, clearance, & regeneration from specific quiescent stem cells
- Cancer: pro-senescence cell changes invoked, arrest proliferation, & recruit their own engulfment by immune cells – unless tumor-suppressor pathways malfunction.
- “age-related pathologies generally rise with approximately exponential kinetics beginning at approximately the mid-point of the species-specific life span (e.g., 50–60 years of age for humans)” - Dr. Judith Campisi