Epigenetic Alterations

Definition

Epigenetic alterations are age-associated changes in the chemical and structural systems that help regulate gene activity without changing the underlying DNA sequence. These include changes in DNA methylation, histone modifications, chromatin organisation, and other mechanisms that influence which genes are accessible or active in a cell. [1] [2] [3]

Why It Matters in Ageing Research

Epigenetic alterations are considered one of the hallmarks of ageing because disrupted gene regulation can affect genome stability, cell identity, inflammation, metabolism, and tissue repair. They are also central to biological-age research, since many epigenetic clocks estimate ageing-related risk from patterns of DNA methylation. [4] [5] [6]

Common Confusion

• Epigenetic alterations do not usually mean mutations in the DNA sequence itself.
• DNA methylation is an important epigenetic mechanism, but it is not the only form of epigenetic regulation.
• Epigenetic clocks use selected methylation patterns as biomarkers; they do not capture every epigenetic change that occurs with ageing.

Related Reading

• Hallmarks of Ageing
• Epigenetics
• Epigenetic Drift
• DNA Methylation
• Epigenetic Clock
• Biological Age

References

1. Pal, S., & Tyler, J. K. (2016). Epigenetics and aging. https://doi.org/10.1126/sciadv.1600584
2. Sen, P., Shah, P. P., Nativio, R., & Berger, S. L. (2016). Epigenetic Mechanisms of Longevity and Aging. https://doi.org/10.1016/j.cell.2016.07.050
3. Booth, L. N., & Brunet, A. (2016). The Aging Epigenome. https://doi.org/10.1016/j.molcel.2016.05.013
4. Lopez-Otin, C., et al. (2013). The Hallmarks of Aging. https://doi.org/10.1016/j.cell.2013.05.039
5. Lopez-Otin, C., et al. (2023). Hallmarks of aging: An expanding universe. https://doi.org/10.1016/j.cell.2022.11.001
6. Horvath, S. (2013). DNA methylation age of human tissues and cell types. https://doi.org/10.1186/gb-2013-14-10-r115