Impairment of IGF-1 Signaling and Antioxidant Response Are Associated with Radiation Sensitivity and Mortality.
Following exposure to high doses of ionizing radiation, diverse strains of vertebrate species will manifest varying levels of radiation sensitivity. To understand the inter-strain cellular and molecular mechanisms of radiation sensitivity, two mouse strains with varying radiosensitivity (C3H/HeN, and CD2F1), were exposed to total body irradiation (TBI). Since Insulin-like Growth Factor-1 (IGF-1) signaling pathway is associated with radiosensitivity, we investigated the link between systemic or tissue-specific IGF-1 signaling and radiosensitivity. Adult male C3H/HeN and CD2F1 mice were irradiated using gamma photons at Lethal Dose-70/30 (LD70/30), 7.8 and 9.35 Gy doses, respectively. Those mice that survived up to 30 days post-irradiation, were termed the survivors. Mice that were euthanized prior to 30 days post-irradiation due to deteriorated health were termed decedents. The analysis of non-irradiated and irradiated survivor and decedent mice showed that inter-strain radiosensitivity and post-irradiation survival outcomes are associated with activation status of tissue and systemic IGF-1 signaling, nuclear factor erythroid 2-related factor 2 (Nrf2) activation, and the gene expression profile of cardiac mitochondrial energy metabolism pathways. Our findings link radiosensitivity with dysregulation of IGF-1 signaling, and highlight the role of antioxidant gene response and mitochondrial function in radiation sensitivity.
['Y Aghdam|Saeed|S|', 'Kenchegowda|Doreswamy|D|', 'Holmes-Hampton|Gregory P|GP|', 'Moroni|Maria|M|', 'P Ghosh|Sanchita|S|']
D000818:Animals D000975:Antioxidants D004307:Dose-Response Relationship, Radiation D005720:Gamma Rays D015870:Gene Expression D007334:Insulin-Like Growth Factor I D008297:Male D051379:Mice D008809:Mice, Inbred C3H D008928:Mitochondria D051267:NF-E2-Related Factor 2 D011836:Radiation Tolerance D011839:Radiation, Ionizing D015398:Signal Transduction D014916:Whole-Body Irradiation
IGF-1 Nrf2 mitochondria oxidative stress radiation injury