电子线照射对小鼠胰岛素生长因子相关蛋白表达的影响

目的:探讨电子线对胰岛素生长因子-1家族蛋白表达的影响,为研究辐射对肝脏的早期损伤提供依据。方法:采用电子线照射小鼠,照射剂量为1、2、4 Gy,用Western blot法检测照射后12、48和72 h小鼠肝脏中胰岛素生长因子1受体(IGF-1R)、胰岛素生长因子结合蛋白1(IGFBP1)、胰岛素生长因子结合蛋白4(IGFBP4)和胰岛素生长因子1(IGF-1)蛋白表达水平的改变。结果:照射剂量为1 Gy时,与对照组相比,IGF-1蛋白在照射后48 h时表达增加,IGFBP1、IGFBP4和IGF1R蛋白的表达在照射后12、48和72 h均表达减少。照射剂量为2 Gy时,IGF-1和IGFBP4蛋白在照射后48 h时表达增加,其余时间点表达减少。IGFBP1蛋白在照射后12 h时表达增加,48和72 h时表达减少。IGF1R蛋白在照射后3个时间点均呈现为表达减少。照射剂量4 Gy时,肝脏中IGF-1、IGFBP1和IGFBP4蛋白均表达减少,IGF1R蛋白在照射后12 h时表达增加,48、72 h时均表达减少(均为P<0.05)。结论:电子线照射后小鼠肝脏中胰岛素生长因子-1家族蛋白多以下调表达为主,与前期基因表达的结果相一致,有可能作为反映放射性工作人员早期肝脏损伤的生物标志物之一。

Effect of electron beam irradiation on expression of insulin growth factor-related protein in mice

OBJECTIVE: To investigate the influence of electronic beams on protein expression of the insulin growth factor system and to provide evidence for radiation-induced early damage in livers of mice. METHODS: Mice were irradiated with electron beam at of 0,1,2 and 4 Gy. At 12,48 and 72 h after irradiation,their livers were removed and used for analyses. Western blot was used to detect changes of protein expressions in insulin growth factor 1 receptor (IGF-1R),insulin growth factor binding protein 1 (IGFBP1),insulin growth factor binding protein 4 (IGFBP4),and insulin growth factor 1 (IGF-1). RESULTS: When the irradiation dose was 1 Gy,IGF-1 protein was highly expressed at 48 h after irradiation,and that for IGFBP1,IGFBP4 and IGF1R protein were at 12,48 and 72 h. When the irradiation dose was 2 Gy,IGF-1 and IGFBP4 proteins were up regulated at 48 h after irradiation,and they were down regulated for the rest of the time. IGFBP1 protein was up regulated at 12 h after irradiation,and it was down regulated at 48 h and 72 h. IGF1R protein was down regulated at three time points after irradiation. When the irradiation dose was 4 Gy,the expressions of IGF-1,IGFBP1,and IGFBP4 proteins was down regulated. IGF1R protein was up regulated at 12 h after irradiation,and it was down regulated at 48 and 72 h. CONCLUSION: Our results show that electron beam irradiation caused down-regulation on protein expression of the insulin growth factor-1 system in the liver of mice. Our results are consistent with those performed using PCR. Based on the study,expression of the insulin growth factor-1 system may be useful as a biomarker for radiation-induced liver injury.