| Previous studies have found that Wide-band electromagnetic pulse(WEMP)causes apoptosis in heart,liver,testis and other tissues of rats.To further explore the damage regulation and apoptosis mechanism of WEMP irradiation parameters on apoptosis,we studied the relationship between the two main irradiation parameters(field strength,pulse number)and the role of calcium signaling related to apoptosis in isolated cells using human amniotic epithelial cells(AECs).It is proposed to lay a preliminary foundation for establishing biophysical models of WEMP caused cell damage.In this experiment,XFdtd 7.3.2 was used to calculate the electromagnetic exposure dose of the cell irradiation system model under WEMP irradiation.The apoptosis of the cells was determined by Annexin V-FITC/PI staining and flow cytometry detection.Fluo-4 AM and other fluorescent staining were used to detect the changes of intracellular calcium distribution and concentration.The cell membrane fluidity was detected using DPH fluorescence polarization method.The level of related proteins in cells was detected using Western blotting.The experimental data were statistically analyzed by SPSS 23.0 software,and the relationship between different WEMP parameters and apoptosis was obtained.The experimental results show that:1.Under the WEMP irradiation conditions used in the experiment,the field strength acting on the culture dish is about 7% of the external field strength,and the maximum temperature rise of the cell layer under the experimental conditions can be predicted as 7.04×10-3?,indicating that WEMP caused mainly nonthermal effect.2.After WEMP irradiation,the effect of field strength(E)towards apoptosis shows a logistic manner while the effect of pulse number(N)shows an exponential manner.E is the major cause of apoptosis and N is the minor,while there is crossinteraction between the two factors.3.WEMP irradiation can change the intracellular calcium concentration.When the extracellular calcium concentration is high,WEMP can increase the calcium concentration in the cytoplasm,and the larger the field strength,the more number of pulses,resulting in higher calcium concentration in cell cytoplasm in a short time.There is a significant correlation with apoptosis.When the extracellular calcium concentration is low,WEMP can reduce the calcium concentration in the cytoplasm,and the field strength is larger,the more the number of pulses,the more obvious decrease calcium concentration in cytoplasm in a short time.4.WEMP irradiation has no significant effect on the membrane fluidity of AECs.The increase of intracellular calcium ion concentration may be due to the effect of WEMP that open the ion channels on the cell membrane.5.WEMP irradiation caused an increase in intracellular calcium,and calcium ions played an important role in complex apoptosis.In this experiment,caspase 9 was spliced and activated,suggesting that calcium is likely to participate in the activation of endogenous apoptosis pathway. |
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