工频磁场对应激活化蛋白激酶及上游激酶磷酸化和活力的影响  

Effects of power-frequency magnetic fields exposure on phosphorylation and enzymatic activity of stress-activated protein kinase and its upstream kinase

作　　者：孙文均[1] 余应年[2] 付一提[1] 姜槐[1] 谢海洋[2] 鲁德强[1] 

机构地区：[1]浙江大学医学院微波研究室,杭州310031 [2]浙江大学医学院病理生理教研室,杭州310031

出　　处：《中华劳动卫生职业病杂志》2002年第4期256-259,共4页Chinese Journal of Industrial Hygiene and Occupational Diseases

基　　金：国家自然科学基金重点资助项目 (3 963 0 10 0 )

摘　　要：目的　研究 5 0Hz工频磁场对细胞内应激活化蛋白激酶 (stress activatedproteinkinase,SAPK/JNK)信号转导途径的影响 ,探索工频磁场生物效应相关的细胞信息转导机制。方法　细胞分别经 0 .4、0 .8mT的工频磁场进行不同时间辐照后 ,利用Western印迹方法 ,比较辐照后细胞与对照细胞胞浆中SAPK及SAPK激酶 (SAPK/ERKkinase 1,SEK1/MKK4 )磷酸化程度。随后以固相激酶分析法(solid phasekinaseassay) ,对经 2个强度分别辐照 15min后的细胞SAPK活力进行测定。结果　 0 .4及0 .8mT工频磁场辐照处理可呈时相性增强SAPK磷酸化 ,并且均在 15min时达到最大值 ,SAPK磷酸化分别提高 2 0 %和 17% ;同时SAPK激酶活力也相应增强 ,分别是对照的 (2 .9± 0 .4 )和 (2 .1± 0 .9)倍。然而 ,0 .8mT诱导SAPK磷酸化的时程长于 0 .4mT ,而脱磷酸化的时程短于 0 .4mT。SAPK上游激酶SEK1/MKK4的磷酸化不受工频磁场的影响。结论　工频磁场可以激活SAPK ,但其激活并非通过SEK1/MKK4激酶途径 ;Objective To study the effects of 50 Hz power frequency magnetic fields on signal transduction pathway of stress activated protein kinase(SAPK),and explore the cellular signal transduction mechanism of the biological effects induced by power frequency magnetic fields. Methods Chinese hamster lung(CHL) cell line was exposed to power frequency magnetic fields with two intensities for different exposure durations.The cytoplasmic protein was extracted and the phosphorylated portion of SAPK and SEK1/MKK4 was measured with Western blotting analysis.The SAPK enzymatic activity was measured by the solid phase kinase assay in cells exposed to power frequency magnetic fields for 15 min. Results Both 0.4 mT and 0.8 mT power frequency magnetic fields could enhance the phosphorylation of SAPK in a time relative course manner,and reached the maximum extent at 15 min,with an increase of 20% and 17% respectively.The solid phase kinase assay showed that the enzymatic activities of SAPK were also increased,which were 2.9±0.4 and 2.1±0.9 times of control respectively.However,the duration of SAPK phosphorylation induced by 0.8 mT was longer than that of 0.4 mT,while the duration and extent of SAPK dephosphorylation was remarkably shorter than that of 0.4 mT.The power frequency magnetic fields under equal conditions could not phosphorylate(activate) the SEK1/MKK4. Conclusion Power frequency magnetic fields could activate the SAPK,but not SEK1/MKK4.It is suggested that power frequency magnetic fields may activate SAPK signal transduction pathway through a kinase other than SEK1/MKK4.The activation mechanism of SAPK of power frequency magnetic fields needs to be identified in more detail.

关 键 词：磷酸化 工频磁场 信号转导 应激活化蛋白激酶 生物学效应 

分 类 号：X591[环境科学与工程—环境工程]