April 02, 2026
New research demonstrates that skin cells can retain a lifelong memory of inflammatory events through heritable epigenetic modifications, providing a mechanistic explanation for recurrent flare-ups in conditions such as psoriasis. Published in Science, the study used mouse models to reveal how successive generations of skin stem cells inherit chemical marks on DNA that regulate gene expression, effectively “remembering” prior tissue damage or inflammation.
The researchers found that, in addition to maintaining DNA sequence information, skin stem cells preserve epigenetic modifications—chemical tags that can activate or repress specific genes. These marks are passed down as stem cells regenerate, enabling the tissue to respond more efficiently to repeated injuries. While this cellular memory can accelerate healing after minor injuries, it also contributes to disease persistence, as cells that “remember” previous inflammatory episodes are more prone to overreacting to environmental triggers, sustaining chronic inflammation.
Experts, including immunologist Shruti Naik of Icahn School of Medicine at Mount Sinai, note that the study provides definitive evidence linking stem cell behavior to epigenetic memory, clarifying a mechanism long suspected but not previously demonstrated at this scale.
These findings highlight the dual nature of skin stem cell memory: while it enhances tissue repair, it also underlies the chronicity of inflammatory skin disorders. Understanding this epigenetic memory offers a pathway toward targeted interventions that could modulate cellular memory, reduce disease recurrence, and improve long-term skin health.
SOURCE: https://www.scientificamerican.com/article/why-your-psoriasis-flares-up-in-the-same-spots/
CREDITS: SCIENTIFIC AMERICAN