Distinctive DNA sequence features define epigenetic longevity of inflammatory memory.

Area of Science:

• Immunology
• Epigenetics
• Dermatology

Background:

• Tissues retain memory of inflammation, increasing sensitivity to future insults.
• Mechanisms sustaining these adaptations through time and cell division are unclear.

Purpose of the Study:

• Investigate lifelong epigenetic memory in epidermal stem cells after skin inflammation.
• Identify molecular drivers of memory persistence in chromatin dynamics.

Main Methods:

• Deep learning analysis of chromatin dynamics in mouse models.
• Investigation of CpG dinucleotide density's role in epigenetic memory.

Main Results:

• Epidermal stem cells store functional, lifelong epigenetic records of psoriasis-like flares.
• CpG-enriched sequences are crucial for reinforcing chromatin accessibility across cell divisions.
• Mechanisms include DNA demethylation, methylation-sensitive transcription factors, and H2A.Z.

Conclusions:

• DNA sequences, once activated by inflammation, orchestrate persistent epigenetic poise.
• This imparts long-lasting memory to stress-sensitive genes, affecting tissue fitness upon recall.