The Effect Of 50HZ 1mT Pulsed Electromagnetic Filed On The Immunomodulation Of Human Umbilical Cord Mesenchymal Stem Cells And Safety Evaluation

Background Mesenchymal stem cells(MSCs)are multipotential nonhematopoietic progenitor cells,and exist in most adult tissues.Due to the reparative potential through self-renewal and differentiation,MSCs have emerged as a promising therapeutic modality for tissue regeneration.Further,clinical interest has been raised by the observation that MSCs possess a range of immunomodulatory properties.However,the clinic efficacy is proportional with the amount of the MSCs,and a large number of MSCs will induce serious side effect,such as pulmonary embolism,liver embolism,renal embolism,fever and erythra.So it is important to improve the immunomodulatory capability of the single cell.Recently,as a safe,non-invasive and economical physiotherapy,electromagnetic field has been widely used in wound healing,bone fracture and anti-tumor treatment.And also some research reported that electromagnetic fields could accelerate MSCs proliferation and differentiation.Objective To investigate the effect of 50 HZ 1m T pulsed electromagnetic field(PEMF)on the immunomodulation of the human umbilical cord MSCs and the safety of the PEMF.Methods1.PEMF: The human umbilical cord MSCs were cultured under an PEMF at 50 Hz at 1m T in the room temperature and segregated from the air.2.Human umbilical cord MSCs were treated with PEMF for 3h/d,4h/d or 5h/d.After 3 days,MTT was taken to observe the change of viability.3.The human umbilical cord MSCs were treated with IFN-γ,PEMF or the combination of both.We detected the m RNA levels of COX2,IL-10,IDO,HGF and TGF-β by Real-time PCR.To verify the improvement of immunomodulatory effects,the THP-1 was stimulated with LPS,and then cultured with the supernatant of the above.The m RNA levels of IL-1β and NF-κB were detected by Real-time PCR.4.To explore the safety of PEMF,flow cytometry experiment was taken to observe the apoptosis,ROS level;comet assay was used to detect the DNA damage.Results1.The cell viability was higher after treated with PEMF,and the group of 4h/d was the highest(p(27)0.05).For the control,MSCs were cultured in the room temperature and segregated from the air,the differences between the 3h/d and4h/d were not significant,but the cell viability of the 5h/d was decreased significantly.For the PEMF,the group of 4h/d was higher than the 3h/d,and the group of 5h/d was also decreased significantly(p(27)0.05).2.PEMF could up-regulate COX2,IL-10,IDO,HGF and TGF-β m RNA levels,but this was not statistically significant(p(29)0.05).For the human umbilical cord MSCs stimulated with IFN-γ firstly,PEMF could up-regulate COX2,IL-10,IDO,HGF and TGF-βm RNA levels significantly(p(27)0.05).And the supernatant of this group could inhibit the expression of NF-κB(p(27)0.05)and IL-1β,but the decrease of IL-1β was not significantly(p(29)0.05).3.PEMF did not cause cell apoptosis,ROS generate and DNA damage(p(29)0.05).Conclusions1.For the human umbilical cord MSCs stimulated with IFN-γ firstly,50 HZ 1m T PEMF could improve the immunomodulation.2.50 HZ 1m T PEMF may not cause radiation injury.