小鼠血清中对电离辐射敏感的蛋白分子研究

Study on radio-sensitive proteins to ionizing radiation in mice serum

拟寻找血清中对电离辐射敏感的蛋白分子,探讨其作为辐射生物标志物的潜力。利用蛋白抗体芯片检测经不同剂量X射线照射后24 h小鼠血清的蛋白分子表达谱,发现47种表达差异超过1.5倍的蛋白,其中胰岛素样生长因子1和2(IGF-1和IGF-2)、胰岛素样生长因子结合蛋白1和3(IGFBP-1和IGFBP-3)丰度较高,与辐射损伤和修复相关且同属于IGFs-IGFBPs调控通路,利用酶联免疫吸附测定技术进一步研究这4种分子和其上游调控蛋白——生长因子(GH)的剂量效应和时间效应。结果显示,与对照组(0 Gy)相比:GH和IGF-1血清水平在照射(0.5、2、4 Gy)后24 h变化趋势不明显,IGF-2、IGFBP-1和IGFBP-3表达水平都具有上升趋势,特别是IGFBP-3,在照射(0.5、2、4 Gy)后表达水平都显著升高(p<0.01),且有明显的剂量依赖效应;在不同剂量X射线照射后的2~24 h内,GH表达水平波动较大,IGF-1无显著变化,IGF-2、IGFBP-1和IGFBP-3表达水平随时间延长有上升趋势,其中,IGFBP-1和IGFBP-3在照射后2~24 h都有较为稳定的表达上调趋势。以上结果表明,血清IGF-2、IGFBP-1和IGFBP-3在X射线照射后表达水平升高,有较好的剂量依赖效应和随时间变化的稳定性,具有作为电离辐射标志物的巨大潜力。

This study aimed to identify serum protein responses to ionizing radiation and to indicate their capacity for serving as radiation biomarkers.We performed antibody-based protein microarray studies to determine the expression profiles of serum proteins in mice 24 h after varying doses of X-ray irradiation.A set of 47 serum proteins with relative increases in expression of≥1.5 fold was identified.Among them,insulin-like growth factors 1 and 2(IGF-1 and IGF-2),and insulin-like growth factor binding proteins 1 and 3(IGFBP-1 and IGFBP-3)had higher abundance and were reported to be involved in radiation-induced DNA damage and repair through the IGFIGFBP axis.Therefore,these four proteins and their upstream regulatory protein-growth factor(GH)were selected for further validation and assessment of their dose and time dependency by enzyme-linked immune sorbent assay.The results revealed that levels of serum GH and IGF-1 were not significantly different from those in the control group(0 Gy)after 0.5,2,and 4 Gy of X-ray irradiation,while levels of serum IGF-2,IGFBP-1,and IGFBP-3 showed an upward trend.Levels of IGFBP-3 were significantly increased,with an obvious dose-dependence(p<0.01).Moreover,between 2 and 24 h post-irradiation,expression of serum GH fluctuated greatly,while IGF-1 showed no significant changes,and levels of IGF-2,IGFBP-1,and IGFBP-3 increased.The upward trends in IGFBP-1 and IGFBP-3 expression were evident from 2 to 24 h,at least.These results demonstrated that levels of serum IGF-2,IGFBP-1,and IGFBP-3 showed significant increases with good dose and time dependent effects after X-ray irradiation,suggesting that these proteins have great potential as biomarkers of ionizing radiation.