The effects of low-dose irradiation on inflammatory response proteins in a 3D reconstituted human skin tissue model

Skin responses to moderate and high doses of ionizing radiation include the induction of DNA repair, apoptosis and stress response pathways. Additionally, numerous studies indicate that radiation exposure leads to inflammatory responses in skin cells and tissue. However, the inflammatory response of skin tissue to low-dose radiation (≤10 cGy) is poorly understood. To address this, we have utilized a reconstituted human skin tissue model (MatTek EpiDermFT™) and assessed changes in 23 cytokines, 24 and 48 h after treatment of skin with either 3 or 10 cGy low dose of radiation. Three cytokines, IFN-γ, IL-2, MIP-1α, were significantly altered in response to low-dose radiation. In contrast, seven cytokines were significantly altered in response to a high radiation dose of 200 cGy (IL-2, IL-10, IL-13, IFN-γ, MIP-1α, TNFα and VEGF) or the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (G-CSF, GM-CSF, IL-1α, IL-8, MIP-1α, MIP-1β and RANTES). Additionally, radiation induced inflammation appears to have a distinct cytokine response relative to the nonradiation induced stressor, TPA. Overall, these results indicate that there are subtle changes in the inflammatory protein levels after exposure to low-dose radiation and this response is a subset of what is seen after a high dose in a human skin tissue model.