低剂量辐射诱导小鼠脾细胞蛋白表达及生物活性

Expression of proteins in mouse splenic cells after low dose radiation and their biological activity\

目的 为了探讨低剂量辐射兴奋效应的分子机理 ,本文作者对昆明小鼠接受 75mGyX射线全身照射后 4h的脾细胞进行了蛋白分子表达的研究。方法 用凝胶过滤和高效液相色谱法 (HPLC)分析蛋白分子表达 ,通过3H TdR掺入的淋巴细胞转化和人外周血淋巴细胞染色体畸变率观察蛋白分子表达的生物活性。结果 发现相对分子质量为 170 0 0、185 0 0和 5 0 0 0 0 3种蛋白质的表达在照射后发生改变 ,这 3种蛋白质分别在脾细胞浆、全脾细胞和脾细胞核中发现 ,其中 170 0 0和 185 0 0的蛋白分子表达下调 ,5 0 0 0 0的蛋白分子表达上调。并且照射后 170 0 0和 185 0 0蛋白质分子表达下调的组分对正常脾细胞的增殖反应具有促进作用 ,185 0 0蛋白质分子表达下调的组分和 5 0 0 0 0蛋白分子表达上调的组分对人外周血淋巴细胞染色体辐射损伤具有保护作用。

Objective\ In order to investigate the mechanisms of the hormetic effect of low dose ionizing radiation,the induction of protein expression in mouse splenic cells after whole\|body irradiation was studied. Methods\ Expression of proteins and their biological activity was detected using gel filtration and high performance liquid chromatography (HPLC) as well as mouse splenic lymphocyte transformation with 3H TdR incorporation and chromosome aberrations of human lymphocytes were observed. Results The changes in expression of three polypeptides with MW 18 500,17 000 and 50 000 were respectively detected in the crude extracts of the whole cell,cytoplasm and nucleus using HPLC.The 17 kD and 18\^5 kD molecules were down\|regulated,while the 50 kD molecule was up\|regulated by low dose X\|irradiation.The proliferative response of splenic lymphocytes from normal mice to ConA was significantly enhanced after the addition of protein fractions containing the reduced amount of 17 kD and 18\^5 kD molecules,but not after the addition of the fraction containing increased amount of 50 kD molecules.The fractions with down\|regulated expression of 18\^5 kD protein and with up\|regulated expression of 50 kD protein showed a protective effect on the chromosome damage caused by radiation. Conclusion\ The changes in expression of protein molecules might play an important role in the mechanism of radiation hormesis.\;