50-Hz magnetic field induces EGF-receptor clustering and activates RAS
50-Hz magnetic field induces EGF-receptor clustering and activates RAS
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DOI：
10.1080/09553000801998875
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发表时间：
2008-01
影响因子：
2.6
通讯作者：
X. Ke;Wenjun Sun;D. Lu;Yi-ti Fu;H. Chiang
中科院分区：
文献类型：
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作者：
X. Ke;Wenjun Sun;D. Lu;Yi-ti Fu;H. Chiang
目的：在以前的研究中，我们发现暴露于50 Hz磁场（MF）可以激活应激激活蛋白激酶（SAPK）和P38丝裂原激活蛋白激酶（MAP）在中国仓鼠肺（CHL）成纤维细胞（P38 MAPK），和同时暴露于相同强度的“噪声”MF抑制这些作用。为了探索SAPK和P38 MAPK可能的作用靶点和上游信号转导分子，进一步验证“噪声”MF对50 Hz MF的干扰作用，研究了MF暴露对表皮生长因子（EGF）受体聚集和Ras蛋白活化的影响。材料与方法：将CHL细胞暴露于0.4 mT的50 Hz正弦磁场中不同时间，采用免疫荧光共聚焦显微镜和共沉淀技术分析细胞膜上EGF受体的聚集和Ras蛋白的活化。EGF治疗作为阳性对照。结果如下：结果表明，与假暴露细胞相比，暴露于50 Hz，0.4 mT的MF 5 min轻微诱导EGF受体聚集，而暴露15 min显著增强受体聚集。与受体聚集相对应，Ras蛋白在暴露于50 Hz MF后也被激活。暴露于“噪声”MF（频率范围从30 - 90 Hz）在相同的强度和持续时间，没有显着影响EGF受体的聚类和Ras蛋白。然而，通过叠加的“噪音”MF，受体聚集和Ras激活所诱导的50 Hz MF的抑制。结论：结果提示，细胞膜受体可能是极低频（ELF）MF与细胞相互作用的重要靶点之一，Ras可能参与了50 Hz MF的信号转导过程。此外，“噪声”MF可以抑制由ELF-MF引起的这些影响。
Purpose: In a previous study, we found that exposure to a 50 Hz magnetic field (MF) could activate stress-activated protein kinase (SAPK) and P38 mitogen-activated protein (MAP) kinase (P38 MAPK) in Chinese hamster lung (CHL) fibroblast cells, and simultaneous exposure to a ‘noise’ MF of the same intensity inhibited these effects. In order to explore the possible target sites and upstream signal transduction molecules of SAPK and P38 MAPK, and further validate the interference effects of ‘noise’ MF on 50 Hz MF, the effects of MF exposure on clustering of epidermal growth factor (EGF) receptors and Ras protein activation were investigated. Materials and methods: CHL cells were exposed to a 50 Hz sinusoidal MF at 0.4 mT for different durations, and clustering of EGF receptors on cellular membrane and Ras protein activation were analyzed using immunofluorescence confocal microscopy and co-precipitation technology. EGF treatment served as the positive control. Results: The results showed that, compared with sham-exposed cells, exposure to a 50 Hz MF at 0.4 mT for 5 min slightly induced EGF receptor clustering, whereas exposure for 15 min enhanced receptor clustering significantly. Corresponding to receptor clustering, Ras protein was also activated after exposure to the 50 Hz MF. Exposure to a ‘noise’ MF (with frequency ranges from 30 – 90 Hz) at the same intensity and durations, did not significantly affect EGF receptor clustering and Ras protein. However, by superimposing the ‘noise’ MF, receptor clustering and Ras activation induced by 50 Hz MF were inhibited. Conclusion: The results suggested that membrane receptors could be one of the most important targets where extremely low frequency (ELF) MF interacts with cells, and Ras may participate in the signal transduction process of 50 Hz MF. Furthermore, a ‘noise’ MF could inhibit these effects caused by ELF-MF.