A Study In The Effects Of 0.4mT ELF-MF On The Cytoskeleton In PC12 Cell

The non-thermal effects of power frequency magnetic field (PFMF) is one of the important topics in bioelectromagnetics research. In previous studies, we have found that, after exposing to 0.4mT 50Hz magnetic field, there were obvious EGFR clustering effects in FL cells and CHL cells, which suggests that EGFR signal pathway is activated. Besides these, the actin microfilaments in cellsalso tended to reorganize. In cell center, the content of MLC decreased.On the contrary, the content of F-actin in cell edge which participated in the formation of pseudopodium and adhesion structures raised. In addition to the studies of non neuronal cells, many studies about neuronal cell also reported that extremely low frequency magnetic fields (ELF-MF) induced cells to produce specific biological effects. For example, epidemiological surveys found occupational exposure to power frequency magnetic field have a big risk for a variety of neurological disorders, symptoms including feeling anxious, depressive, exhausted in exposed people groups. Besides, several studies indicated that early electromagnetic exposure might be one of important risk factors for Alzheimer’s disease (AD).In order to reveal the electromagnetic biological effects of nerve cells, this study investigated the field-induced cytoskeleton effects of PC 12 cells and its intrinsic mechanism by using various methods such as immunofluorescence, western blot and FRET techniques. Due to the special relationship between the microfilament self-assembly frequency and the frequency of PFMF, there may be a frequency window effect of ELF-MF on the efficiency on the actin-skeleton assembly.The results showed that (1) 0.4mT,30minPFMF irradiation promoted the aggregation of EGFR in PC 12 and FL cell surface; (2) there was an increase in the intracellular concentration of calcium ion, and calcium signaling protein (CaMKII) was activated; (3) The activity of microtubule-associated protein (Tau) changed, and finally promoted the depolymerization of microtubule and microfilament, making parapodium and adhesion structure increased in PC 12 and FL cells; (4) Experiments on both cell and protein levels proved that 50Hz MF exposed group induced the most significant interference effect on actin assembility In conclusion, our studies proved that after exposing PC 12 cells to 0.4mT PFMF for 30min, the dynamic balance of cytoskeleton assembly was broken. The central microtubule tend to deploymerize, however creeping structure in cell edge increased, and all these effects could be a result of abnormal signal pathway activation of EGFR and calcium. In addition to, we propose that 50 Hz is likely to be one of the MF frequency windows for the MF-induced-interference to cytoskeleton.