ABSTRACT
Objective To Investigate the influence of high-intensity pulsed electromagnetic field (HIPEMF) on neural differentiation of neonatal rats neural stem cells in vitro.Methods Neural stem cells (NSCs) were isolated from the subventricular zone of 3-day-old neonatal rats and cultured with serum-free condition medium for 14 days.All the NSCs were then randomly classified into an experimental group which received the stimulation of HIPEMF (0.1 Hz,4 T,8 pulses) and a control group which received no special intervention.Differentiation of the culture was induced by addition of 10％ fetal bovine serum on the first day after intervention,the morphological changes of cells were observed under the microscope at different time points.The NSCs adhered to the wall and differentiated for seven days,the immunofluorescence was employed to observed and calculate the ratio of differentiated cells with astrocyte marker GFAP or neuronal markers TUJ1.RT-PCR and western blotting were used to measure the expression levels of the differentiated cells based on gene and protein levels,respectively.Results Immunofluorescence staining showed the number of TUJI positive cells in the experimental group(33.4％ ± 5.1％)was significantly more than the control group (26.5％ ± 7.0％),while the number of GFAP positive cells was decreased(23.9％ ± 5.0％) as compared with the control group(36.2％ ± 2.2％).RT-PCR showed that the TUJ1 mRNA expression levels in the experimental group was (1.682 ± 0.086) times of the control group.Western blot showed that the expression of TUJ1 (0.729 ±0.061) in the experimental group was higher than in the control group (0.590 ± 0.157),while the expression of GFAP in the experimental group (0.566 ± 0.056) was less than in the control group(1.034 ± 0.051).Conclusions HIPEMF facilitates differentiation of neural stem cells to neurons,at the cost of reducing astrocytic differentiation.
ABSTRACT
The effects of high-intensity pulsed electromagnetic stimulation (HIPEMS) on proliferation and differentiation of neonatal rat neural stem cells in vitro were investigated. Neural stem cells derived from neonatal rats were exposed to 0.1 Hz,0.5-10 Tesla (T) [8 groups of B-I,respectively],5 stimuli of HIPEMF. The sham exposure controls were correspondingly established. Inverted phase contrast microscope was used to observe the cultured cells,MTT assay to detect the viability of the cells as expressed by absorhance (A) value,and flow cytometry to measure differentiation of neural stem cells. The results showed that A values of neural stem cells in both 3.0 T and 4.0 T groups were significantly higher than the other groups 24 to 168 h post HPEMS,indicating a strong promotion of the growth of neural stem cells (P＜0.05). The A values of neural stem cells in the 6.0 T,8.0 T,and 10.0 T groups were lower than the sham exposure control group,indicating a restraint of the growth of neural stem cells. The rate of neuron-specific enolase-positive neurons revealed by flow cytometry in HPEMS groups was the same as that in control group (P＞0.05). It was suggested that 0.1 Hz,5 pulses stimulation of HPEMS within certain scale of intensity (0.5-10.0 T),significantly promoted the growth of neural stem cells with the rational intensity being 4.0 T.