The detailed summary of this article is not available in your language or incomplete. Would you like to see a complete translation of the summary?
Then please contact us →
研究目的（著者による）
The effects of exposure of human amniotic cells to a 50 Hz magnetic field on apoptosis and mitochondrial reactive oxygen species and the role of mitochondrial permeability transition (MPT) should be investigated.
詳細情報
MPT is defined as an increase in the permeability of the mitochondrial membranes for small molecules via opening of so called MPT pores. In a previous study by the authors (Feng et al. 2016), it was found that exposing human amniotic cells to a 50 Hz magnetic field induced an increase in intracellular reactive oxygen species (ROS) that in turn caused MPT. The study investigated the biological implications of this result, suspecting an anti-apoptotic effect. Cells were exposed to a 0.4 mT magnetic field for up to 2 hours and were cultivated for up to 36 hours afterwards. In some approaches, cells were pretreated Bongkrekic acid, SB216763, cyclosporine A (inhibitors of MPT), acetylcysteine (ROS scavenger) or LY294002 (inhibitor of the PI3K/Akt signaling pathway) and/or treated with staurosporine (0,1 µM for 4 h) afterwards, to induce early apoptosis. Moreover, cells were exposed to a 0.2, 1 or 2 mT magnetic field for 60 min and treated with staurosporine afterwards. For each exposure, a separate sham exposure was used. Positive controls were used.
影響評価項目
apoptosis and mitochondrial reactive oxygen species and the role of mitochondrial permeability transition
two exposure chambers in incubator with 95% air humidity and 5% CO2; the temperature was kept at 37.0 ± 0.1°C
ばく露装置の詳細
each chamber contained a set of square Helmholtz coils (20 cm Π20 cm), which were double-wrapped with two lines of copper wire and encased by mu-metal to shield cells from stray fields; a fan in the wall made air and temperature uniform between chambers and incubator; cell dishes were put in the center of the coils; the magnetic field was perpendicular to the dishes
Sham exposure
A sham exposure was conducted.
Additional information
one chamber was used for sham exposure with opposite direction currents fed into the coils; exposure and the corresponding sham exposure was conducted simultaneously
分子生合成: total protein concentration (BCA protein assay), protein expression of phosphorylated protein kinase B (marker for activation of the anti-apoptotic PI3K/Akt pathway, Western blot)
Exposure to a magnetic field alone had no significant effect on cell viability or early apoptosis compared to the sham exposure conditions. However, exposure to a magnetic field of 0.4 mT or 1 mT for 1 hour significantly reduced early apoptosis induced by staurosporine compared to sham exposed cells. As other magnetic flux densities or exposure durations did not show such an effect, the authors assumed an window effect for exposure duration (1 h) and intensity (0.4 mT to 1 mT). In cells treated with the MPT inhibitor cyclosporine A and exposed to a 0.4 mT magnetic field for 1 hour, the mitochondrial reactive oxygen species level was significantly increased in comparison to cells only treated with the inhibitor, indicating that magnetic field-induced ROS are released into the cytoplasm via MPT. Treatment with MPT inhibitors Bongkrekic acid, SB216763, cyclosporine A or the ROS scavenger acetylcysteine significantly decreased the anti-apoptotic effect of the magnetic field, suggesting a relation between ROS release and the anti-apoptotic effect of the magnetic field. Finally, the protein expression of phosphorylated protein kinase B was found to be significantly increased after exposure to the 0.4 mT magnetic field for 60 minutes compared to the sham exposure, but not when combined with MPT inhibitors orROS scavengers. The authors conclude that exposure of human amniotic cells to a 50 Hz magnetic field might have an anti-apoptotic effect via mitochondrial reactive oxygen species release through mitochondrial permeability transition and subsequent activation of the PI3K/Akt pathway.
