Institute of Computing Medicine, Third Military Medical University, Chongqing, 400038, China; Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.
Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.
Toxicol Lett. 2014 Aug 4;228(3):216-24. doi: 10.1016/j.toxlet.2014.05.004. Epub 2014 May 9.
The increasing exposure to radiofrequency (RF) radiation emitted from mobile phone use has raised public concern regarding the biological effects of RF exposure on the male reproductive system. Autophagy contributes to maintaining intracellular homeostasis under environmental stress. To clarify whether RF exposure could induce autophagy in the spermatocyte, mouse spermatocyte-derived cells (GC-2) were exposed to 1800MHz Global System for Mobile Communication (GSM) signals in GSM-Talk mode at specific absorption rate (SAR) values of 1w/kg, 2w/kg or 4w/kg for 24h, respectively. The results indicated that the expression of LC3-II increased in a dose- and time-dependent manner with RF exposure, and showed a significant change at the SAR value of 4w/kg. The autophagosome formation and the occurrence of autophagy were further confirmed by GFP-LC3 transient transfection assay and transmission electron microscopy (TEM) analysis. Furthermore, the conversion of LC3-I to LC3-II was enhanced by co-treatment with Chloroquine (CQ), indicating autophagic flux could be enhanced by RF exposure. Intracellular ROS levels significantly increased in a dose- and time-dependent manner after cells were exposed to RF. Pretreatment with anti-oxidative NAC obviously decreased the conversion of LC3-I to LC3-II and attenuated the degradation of p62 induced by RF exposure. Meanwhile, phosphorylated extracellular-signal-regulated kinase (ERK) significantly increased after RF exposure at the SAR value of 2w/kg and 4w/kg. Moreover, we observed that RF exposure did not increase the percentage of apoptotic cells, but inhibition of autophagy could increase the percentage of apoptotic cells. These findings suggested that autophagy flux could be enhanced by 1800MHz GSM exposure (4w/kg), which is mediated by ROS generation. Autophagy may play an important role in preventing cells from apoptotic cell death under RF exposure stress.
手机使用产生的射频（RF）辐射日益增加，引起了公众对 RF 辐射暴露对男性生殖系统的生物学影响的关注。自噬有助于在环境压力下维持细胞内的稳态。为了阐明 RF 暴露是否会诱导精母细胞发生自噬，将小鼠精母细胞源性细胞（GC-2）分别置于特定吸收率（SAR）值为 1w/kg、2w/kg 或 4w/kg 的 1800MHz 全球移动通信系统（GSM）信号下的 GSM-Talk 模式中，暴露 24 小时。结果表明，RF 暴露可使 LC3-II 的表达呈剂量和时间依赖性增加，在 SAR 值为 4w/kg 时变化显著。通过 GFP-LC3 瞬时转染实验和透射电子显微镜（TEM）分析进一步证实了自噬体的形成和自噬的发生。此外，用氯喹（CQ）共同处理增强了 LC3-I 向 LC3-II 的转化，表明 RF 暴露可以增强自噬流。细胞暴露于 RF 后，细胞内 ROS 水平呈剂量和时间依赖性显著增加。用抗氧化剂 NAC 预处理可明显降低 LC3-I 向 LC3-II 的转化，并减弱 RF 暴露引起的 p62 降解。同时，在 SAR 值为 2w/kg 和 4w/kg 时，RF 暴露后磷酸化细胞外信号调节激酶（ERK）明显增加。此外，我们观察到 RF 暴露不会增加凋亡细胞的百分比，但抑制自噬会增加凋亡细胞的百分比。这些发现表明，1800MHz GSM 暴露（4w/kg）可通过 ROS 生成增强自噬流。自噬可能在 RF 暴露应激下防止细胞发生凋亡性细胞死亡中发挥重要作用。
