Department of Biochemistry and Molecular &Cellular Biology and Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, USA.
Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, Jeddah, Saudi Arabia.
Sci Rep. 2016 Aug 25;6:31853. doi: 10.1038/srep31853.
Travel into outer space is fraught with risk of exposure to energetic heavy ion radiation such as (56)Fe ions, which due to its high linear energy transfer (high-LET) characteristics deposits higher energy per unit volume of tissue traversed and thus more damaging to cells relative to low-LET radiation such as γ rays. However, estimates of human health risk from energetic heavy ion exposure are hampered due to lack of tissue specific in vivo molecular data. We investigated long-term effects of (56)Fe radiation on adipokines and insulin-like growth factor 1 (IGF1) signaling axis in mouse intestine and colon. Six- to eight-week-old C57BL/6J mice were exposed to 1.6 Gy of (56)Fe ions. Serum and tissues were collected up to twelve months post-irradiation. Serum was analyzed for leptin, adiponectin, IGF1, and IGF binding protein 3. Receptor expressions and downstream signaling pathway alterations were studied in tissues. Irradiation increased leptin and IGF1 levels in serum, and IGF1R and leptin receptor expression in tissues. When considered along with upregulated Jak2/Stat3 pathways and cell proliferation, our data supports the notion that space radiation exposure is a risk to endocrine alterations with implications for chronic pathophysiologic changes in gastrointestinal tract.
进入外太空充满了暴露于高能重离子辐射（如 56Fe 离子）的风险，由于其具有高线性能量转移（高 LET）特性，因此在穿过组织时每单位体积沉积的能量更高，相对于低 LET 辐射（如 γ 射线）对细胞的损伤更大。然而，由于缺乏组织特异性的体内分子数据，高能重离子暴露对人类健康风险的估计受到阻碍。我们研究了（56）Fe 辐射对小鼠肠道和结肠中脂肪因子和胰岛素样生长因子 1（IGF1）信号轴的长期影响。6 至 8 周龄的 C57BL/6J 小鼠接受 1.6 Gy 的（56）Fe 离子照射。在照射后长达 12 个月收集血清和组织。分析血清中的瘦素、脂联素、IGF1 和 IGF 结合蛋白 3。研究了组织中受体表达和下游信号通路改变。照射增加了血清中的瘦素和 IGF1 水平，以及组织中的 IGF1R 和瘦素受体表达。当与上调的 Jak2/Stat3 途径和细胞增殖一起考虑时，我们的数据支持这样一种观点，即太空辐射暴露是内分泌改变的风险，这对胃肠道的慢性病理生理变化有影响。
