The Effects Of50Hz Magnetic Field Exposure On Mitochoadrial Related Apoptosis Pathways In FL Cells

Objective:To explore the effects of50Hz magnetic field (MF) exposure on mitochondrial membrane, related proteins and apoptosis in human amnion (FL) cells.Methods:FL cells were cultured in12plates for24h, loaded with calcein and cobalt (Co2+) for20min, then exposed to50Hz,0.4mT MF for different durations (5min,15min,30min,60min and120min). After that, cells were collected and analyzed the calcein fluorescence for mitochondrial permeability transition pore (MPTP) by flow cytometry. In order to investigate the relationship between reactive oxygen species (ROS) and MPTP, FL cells were pretreated with N-acetylcysteine (NAC), a ROS scavenger. FL cells were cultured in035mm petri dish for24h, exposed to50Hz,0.4mT MF for different durations (5min,15min,30min and60min), then cells were loaded with JC-1and analyzed for mitochondrial membrane potential (MMP) by flow cytometry. Western blot was used to detect the level of cytochrome c in cytoplasm when cells were expose to MF for60min, and apoptosis of FL cells were analyzed by flow cytometry after exposure to MF for60min and sequentially cultured for different durations (Oh,3h,6h,12h,24h,36h).Results:The results showed that compared with sham group, exposure to MF for30min or60min could increase the mitochondrial membrane permeability of FL cells. Especially, the difference in the60min group was statistically significant (P<0.05). The increase of mitochondrial membrane permeability induced by MF could be inhibited completely by pretreatment with NAC. Mitochondrial membrane potential had no obvious change after exposure to MF for different durations. The results showed that the level of cytochrome c in cytoplasm was increased after exposure to MF for60min, and the difference was statistically significant (P<0.05). However, the flow cytometry results indicated that apoptosis of FL cells was no significant change when cells were exposed to MF for60min and sequentially cultured up to36h.Conclusions:1. Exposure FL cells to50Hz0.4mT MF could increase mitochondrial membrane permeability which possibly mediated by ROS.2.50Hz0.4mT MF exposure had no effect on mitochondrial membrane potential in FL cells.3. Exposure to MF could increase the level of cytochrome c in cytoplasm, however, MF did not induce apoptosis of FL cells.