Inflammatory immune cell groups expand in aging mouse skin
Experiments on skin removed from older mice suggested that substances released by blood immune cells could partly counter age-related changes.
Paper by Melanie Salek, Katharina Klas, Lisa Auer et al.
Limit: Macrophage expansion was assessed as cell proportions, which can rise when other cells decline
Edited by Boris Djordjevic · AgingResearch.News
An animal study compared gene activity in individual back-skin cells from male C57BL/6 mice aged 8, 26 and 52 weeks. Macrophages, immune cells involved in inflammation, made up a larger share of cells in the oldest skin. Three of four macrophage groups expanded or appeared with age.
Analysis predicted increased signaling from macrophages to fibroblasts, cells that make skin’s supporting material. Some fibroblasts had higher activity of genes linked to collagen and scarring. Collagen gene activity increased, but one collagen protein decreased, and collagen fibers appeared disorganized. In experiments on aged skin outside the body, researchers applied substances released by blood immune cells exposed to radiation. These substances shifted the mix of macrophages toward a younger-like composition and reduced the activity of fibroblast genes linked to scarring.
Why it matters
Chronic low-grade inflammation accompanies skin aging. The work addresses which immune-cell changes may be involved as the skin’s supporting material is remodeled.
Caveats
The blood-cell secretions were tested on removed skin, not in living animals. Results in male mice do not establish effects in females or people.
- Peripheral blood mononuclear cell secretome
- Inflammation
- Extracellular matrix remodeling
- Fibrosis
- COL5A3
- Mice
The paper
Melanie Salek, Katharina Klas, Lisa Auer et al.
Frontiers in Cell and Developmental Biology, Oct 30, 2026, CC BY, Accepted, not yet published
