Accelerated Senescence in Skin in a Murine Model of Radiation-Induced Multi-Organ Injury
February 2017
in “
Journal of radiation research
”
radiation-induced skin injury C57BL/6 mice high-dose radiation inflammation erythema dry desquamation ulceration mast cell infiltration fibrosis collagen deposition human keratinocyte cultures p21/waf1 senescence marker apoptosis activated caspase-3 immunohistochemistry epithelial stem cells hair follicles radiation skin injury redness skin peeling skin ulcers mast cells skin fibrosis collagen skin cell cultures p21 cell aging marker cell death caspase-3 stem cells hair roots
TLDR High-dose radiation speeds up aging in skin stem cells.
The study investigated the cellular mechanisms of radiation-induced skin injury using C57BL/6 mice exposed to high-dose radiation (14, 16, or 17 Gy). It was found that while 14 Gy caused mild inflammation without visible hair loss or erythema, 16 or 17 Gy led to dry desquamation, erythema, and mild ulceration within 14 days. Histological analysis showed inflammation with mast cell infiltration and, after 80 days post-17 Gy irradiation, fibrosis with collagen deposition. In human keratinocyte cultures, 17.9 Gy irradiation upregulated p21/waf1, a senescence marker. In mice, this marker was detected 7 days post-irradiation, and a marker of apoptosis (activated caspase-3) was found at 30 days. Immunohistochemistry showed a reduction in epithelial stem cells from hair follicles between 14-30 days post-irradiation, with increased p21/waf1 expression in the stem cell region at 14 days post 17 Gy irradiation. The results suggest that radiation causes accelerated senescence in skin stem cell regions.
