电离辐射对小鼠胸腺细胞蛋白质表达的影响

Effect of ionizing radiation on protein expression in murine thymocytes

目的 :观察低剂量 X射线全身照射诱导小鼠胸腺细胞蛋白质表达变化及对细胞内外蛋白质交换的影响。方法 :采用双向电泳方法。结果 :75m Gy X射线全身照射小鼠后 4h,细胞浆出现 5个新蛋白点、4个增强蛋白点及 3个减弱蛋白点。正常细胞浆中的 5个蛋白点在照射后消失。照射后细胞外液出现 1个新蛋白点、1个增强蛋白点及 1个减弱蛋白点。正常细胞外液中的 3个蛋白点在照射后消失。正常细胞浆中的 2个蛋白点在照射后分别减弱和消失 ,而在细胞外液中出现和增强。正常细胞外液中的 2个蛋白点在照射后消失 ,而出现在细胞浆中。结论 :低剂量辐射诱导小鼠胸腺细胞蛋白质表达变化 。

Objective\ Alterations of protein expression in cytosol and extracellular fluid and exchanges between intracellular and extracellular proteins of thymocytes in mice 4 hours after whole body irradiation with 75 mGy X rays were investigated.Methods\ Two dimensional electrophoresis was used.Results\ It was found that Alterations of 12 proteins ranging in size from 10 to 53 kD with their pI distribution from 5.0 to 8.2 were displayed in the cytoplasmic fraction of thymocytes in irradiated mice,of which there were 5 novel proteins,4 upregulated proteins and 3 down regulated proteins,and 5 proteins ranging in size from 32 to 67 kD with their pI distribution from 5.8 to 7.7 disappeared after irradiation.Alterations of 3 proteins ranging in size from 15 to 67 kD with their pI distribution from 5.1 to 8.2 were displayed in the extracellular fluid of thymocytes in irradiated mice,of which there were one novel protein,one up regulated protein and one down regulated protein and 3 proteins ranging in size from 13 to 69 kD with their pI distribution from 5.0 to 8.0 disappeared after irradiation.It was shown that a protein molecule in the sham irradiated cytosol of thymocytes appeared in the extracellular fluid after irradiation and a protein molecule in the sham irradiated cytosol was decreased after irradiation and increased in the extracellular fluid.Two proteins in sham irradiated extracellular fluid appeared in the thymocyte cytosol after irradiation.Conclusion\ The results suggest that alterations of protein expression and exchanges of protein molecules occurred between intracellular and extracellular compartments after irradiation.These findings may have implications in the mechanism of immunoenhancement and adaptive response induced by low dose radiation.The elucidation of the nature and mode of action of these protein molecules remains to be clarified in future studies.