工频磁场辐照导致细胞连接蛋白Cx43的异常移位

Abnormal shift of connexin 43 gap-junction protein induced by 50 Hz electromagnetic fields in Chinese hamster lung cells

目的 研究 5 0Hz正弦磁场对细胞连接蛋白Cx4 3移位的影响 ,以探索极低频磁场 (ELFMF)抑制细胞间隙连接通讯 (GJIC)的机制。方法 用 5 0Hz、0 .8mT的正弦磁场和 (或 )十四酰基咐哌醇酯 (TPA ,5ng/ml)对培养的中国仓鼠肺成纤维细胞 (CHL)处理 2 4h(其中TPA处理 1h)。采用间接免疫荧光细胞化学法和激光共聚焦显微镜进行连接蛋白Cx4 3定位的测定 ;采用Westernblot方法检测胞浆和核内Cx4 3蛋白的含量。结果 正常组细胞间连接处有明亮的点状标记 ,连接成线 ;TPA处理组、0 .8mT正弦磁场单独作用组及 0 .8mT正弦磁场联合TPA处理组细胞的连接处标记斑点均较正常组减少 ,大量Cx4 3蛋白标记斑点出现在胞浆内 ,且在核附近聚集。各组核内Cx4 3蛋白条带很淡 ,而胞浆内Cx4 3蛋白含量ELF组 (2 .0 3± 0 .89)和TPA组 (2 .4 3± 0 .82 )明显增加 ,与正常组 (1.0 4± 0 .17)相比 ,差异有显著性 (P <0 .0 1)。结论 5 0Hz正弦磁场直接和 (或 )协同TPA抑制体外培养细胞GJIC功能与细胞连接蛋白Cx4

Objective To study the effects of extremely low frequency magnetic fields(ELF MF) on the amount and localization of connexin 43(Cx43) gap junction protein in the Chinese hamster lung(CHL) cells,and to explore the mechanism of ELF MF suppression on gap junctional intercellular communication(GJIC). Methods The cells were irradiated for 24 h with 50 Hz sinusoidal magnetic field at 0.8 mT without or with 12 O tetradecanoylphorbol 3 acetate(TPA),5 ng/ml for 1 h.The localization of Cx43 proteins were performed by indirect immunofluorescence histochemical analysis and detected by confocal microscopy.The second experiment was conducted to examine the quantity of Cx43 proteins level in nuclei or cytoplasm and detected by Western blotting analysis. Results The cells exposed to TPA for 1 h displayed less bright labelled spots in the regions of intercellular junction than the normal cells.Most of Cx43 labelled spots occurred in the cytoplasm and aggregated near the nuclei.At the same time,the amount of Cx43 protein in cytoplasm were increased[(2.03±0.89) in ELF group,(2.43± 0.82) in TPA group] as compared to normal control(1.04±0.17)(P<0.01). Conclusion Inhibition on GJIC function by ELF MF alone or combined with TPA may be related with the shift of Cx43 from the regions of intercellular junction to the cytoplasm.