What this means
Researchers studied how radiation causes skin to stiffen and scar. They found a loop between aging cells and immune cells that seems to drive it. The drug ABT-263 reduced scarring in these mice, but this does not show it works in people.
Plain-English summary written by an AI model from the abstract. The original is below.
- Who it was tested in
- Mice, plus cells grown in a lab dish
- Kind of research
- A study
The science
- Original title
- A senescence-driven fibroblast-macrophage feed-forward circuit promotes radiation induced cutaneous fibrosis.
- Authors
- Chung EJ, Kc S, Kwon S et al.
- Journal
- International journal of radiation oncology, biology, physics
- Published
- Oct 24, 2026
- Study type
- Study
- PMID
- 42925940 ↗
Abstract
Background
Therapeutic radiation for superficial tumors may cause cutaneous fibrosis, a late side effect with limited treatment options. Here, we investigated the underlying mechanisms driving radiation-induced cutaneous fibrosis.
What they did
C3H/HeN mice received 35 Gy unilateral hind limb irradiation. Cutaneous tissues from irradiated and contralateral unirradiated legs were analyzed by spatial whole transcriptome profiling using the GeoMx Digital Spatial Profiler platform. Beginning at 5 weeks after irradiation, mice received the senolytic agent ABT-263 (50 mg/kg/day) or vehicle (n ≥ 10/group) by oral gavage (5 consecutive days followed by 2-week rest for 3 cycles). Hind limb contracture was assessed at 150 days after irradiation. Senescence and macrophage markers were evaluated by immunohistochemistry and quantitative PCR. Cellular senescence and senescence-associated secretory phenotype (SASP) factors were evaluated in irradiated fibroblasts and their culture media using senescence-associated β-galactosidase activity assays and multiplex immunoassays. The senolytic activity of ABT-263 in irradiated primary fibroblasts and effects of ABT-263 on primary macrophage cultures were evaluated in vitro.
What they found
Spatial whole-transcriptomic analysis of irradiated murine dermis identified expression patterns consistent with macrophage activation, extracellular matrix remodeling, and a senescence-associated secretory phenotype (SASP)-rich environment. In vitro studies identified that the irradiated fibroblast-derived SASP induced a senescent phenotype in unirradiated fibroblasts and macrophages. SASP-induced senescent-like macrophages acquired a CD206+ profibrotic phenotype and in concert with activated fibroblasts, initiated a feed-forward loop amplifying IL-6 and collagen production. SASP exposure increased expression of Bcl-2 family proteins in macrophages and fibroblasts, rendering both populations susceptible to clearance by the senolytic agent ABT-263. In vivo, ABT-263 effectively mitigated radiation-induced dermal fibrosis, depleted senescent fibroblasts and CD206⁺ macrophages, and reduced IL-6 expression Our findings identify senescence-driven reciprocal macrophage-fibroblast interactions as key mediators of cutaneous fibrosis and demonstrate the therapeutic potential of senolytic interventions for treating late radiation-induced skin injury.
The authors' abstract, grouped under plain headings from its own section labels.
Chung EJ, Kc S, Kwon S et al. A senescence-driven fibroblast-macrophage feed-forward circuit promotes radiation induced cutaneous fibrosis. International journal of radiation oncology, biology, physics. 2026. doi:10.1016/j.ijrobp.2026.10.013. PMID: 42925940. https://pubmed.ncbi.nlm.nih.gov/42925940/
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