Age-Related Alterations in Macrophage Distribution and Function Are Associated With Delayed Cutaneous Wound Healing

Area of Science:

• Immunology
• Gerontology
• Wound Healing Research

Background:

• Ageing is associated with delayed wound healing and chronic inflammation.
• The cellular and molecular mechanisms behind impaired healing in aged individuals are not fully understood.

Purpose of the Study:

• To characterize ageing-associated changes in macrophages within wounds.
• To investigate transcriptomic differences in macrophages from young and aged mouse wounds.

Main Methods:

• Full-thickness wounds were created in young and aged C57BL/6J mice.
• Wound tissues were analyzed on Days 3 and 7 post-wounding using immunohistochemistry, flow cytometry, and RNA sequencing.

Main Results:

• Aged wounds had significantly fewer macrophages compared to young wounds.
• Macrophages from aged wounds showed reduced expression of cell cycle, DNA replication, and repair genes.
• Aged macrophages exhibited an elevated pro-inflammatory gene expression profile, linked to poor inflammation resolution and increased tissue damage.

Conclusions:

• Impaired wound healing in aged individuals is characterized by macrophages with diminished proliferative capacity and heightened inflammatory responses.
• These macrophage-associated pathways represent potential therapeutic targets for enhancing wound healing in the elderly.