低剂量辐射激活小鼠脾细胞CREB及NF-κB

Activation of Transcription Factors CREB and NFκB in Mouse Spleen by Low Dose Radiation.

采用凝胶电泳迁移率变化分析和寡核苷酸竞争抑制方法检测低剂量Ｘ射线整体照射对小鼠脾细胞基因转录调控的影响．７５ｍＧｙＸ射线全身照射小鼠后４ｈ，脾细胞核蛋白提取物的ＣＲＥＢ及ＮＦκＢ与其基因启动部位增强子控制序列的结合活性较相同浓度的对照核蛋白提取物分别增强７倍及５倍．竞争抑制试验证实ＣＲＥＢ及ＮＦκＢ与其控制序列特异地结合．提示低剂量Ｘ射线全身照射选择性地激活脾细胞ＣＲＥＢ及ＮＦκＢ，通过与增强子控制序列位点的结合，特异地诱导基因转录，从而引起功能激活．

The effect of wholebody irradiation (WBI) on transcriptional regulation in mouse spleen was studied using gel electrophoresis mobility shift assay (EMSA) and oligonucleotide competitive inhibition analysis. Binding of nuclear protein extract from splenic cells to [γ32P] ATP labeled CREB and NFκB consensus sequences was found to be increased 4 h after WBI with 75 mGy Xrays, being 7 and 5 times higher, respectively, than that of the shamirradiated control. Competitive inhibition analysis with excessive amount of unlabeled consensus sequences completely blocked the binding in corresponding EMSA, demonstrating the specificity of the reaction. The results suggest that low dose WBI could selectively activate the transcription factors CREB and NFκB, which would induce specific gene transcription in the splenic cells leading to their functional activation.