Cellular Senescence

Definition

Cellular senescence is a state in which a cell stops dividing but remains metabolically active. These cells often change their behavior, resist re-entering the cell cycle, and can release signaling molecules that affect nearby tissue. Senescence can be triggered by repeated cell division, DNA damage, oncogene activation, or other forms of cellular stress. [2] [3] [5]

Why It Matters in Ageing Research

Senescence matters because it is both protective and potentially harmful. In some contexts, it helps prevent damaged cells from becoming cancerous and can support wound-healing responses. But when senescent cells accumulate and persist with age, their signaling can contribute to inflammation, tissue dysfunction, and age-related disease processes. [4] [6] [9]

Common Confusion

• Senescence is not the same as quiescence, which is a reversible pause in cell division.
• Senescence is not identical to apoptosis, which is programmed cell death.
• Senescent cells are not always harmful; context and persistence matter.

Related Reading

• What Triggers Cellular Senescence?
• The SASP Explained
• Senescence vs Apoptosis
• Inflammaging

References

1. Serrano, M., et al. (1997). Oncogenic ras provokes premature cell senescence associated with accumulation of p53 and p16INK4a. https://www.cell.com/cell/fulltext/S0092-8674(00)81890-4
2. d’Adda di Fagagna, F. (2008). Living on a break: Cellular senescence as a DNA-damage response. https://www.nature.com/articles/nrc2440
3. Coppé, J. P., et al. (2010). The senescence-associated secretory phenotype: The dark side of tumor suppression. https://www.annualreviews.org/doi/10.1146/annurev-pathol-121808-102144
4. Muñoz-Espín, D., & Serrano, M. (2014). Cellular senescence: From physiology to pathology. https://www.nature.com/articles/nrm3823
5. Demaria, M., et al. (2014). An essential role for senescent cells in optimal wound healing through secretion of PDGF-AA. https://www.sciencedirect.com/science/article/pii/S1534580714007690
6. López-Otín, C., et al. (2013). The hallmarks of aging. https://www.cell.com/cell/fulltext/S0092-8674(13)00645-4
7. Franceschi, C., et al. (2018). Inflammaging: A new immune–metabolic viewpoint for age-related diseases. https://www.nature.com/articles/s41574-018-0059-4
8. Childs, B. G., et al. (2015). Cellular senescence in aging and age-related disease: From mechanisms to therapy. https://www.nature.com/articles/nm.4000