RESUMO
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.
RESUMO
Objective To study the mechanism by which a high-intensity pulsed electromagnetic field (HIPEMF) (0.1 Hz,4 T,8 pulses) facilitates the proliferation of neural stem cells by detecting the expression of β-catenin genes and protein.Methods Neural stem cells (NSCs) were isolated from the sub-ventricular zone (SVZ) of neonatal rats and cultured in supplemented,serum-free medium for two weeks.The NSCs were then divided into an experimental group exposed to a HIPEMF for 8 pulses and a control group given sham stimulation.The gene and prorein expression of β-catenin in the NSCs were assayed by RT-PCR and Western blotting on the 1st,3rd,5th and 7th day after the stimulation.Results The NSCs' cloned spheres were round and translucent,and showed red fluorescence after staining with anti-nestin (cy3).The RT-PCR results showed β-catenin genes were highly expressed in the exposed group (significantly more than in the controls).The Western blotting showed that expression of β-catenin protein was also higher in the experimental group,especially at the 7th day after stimulation,a difference which was also statistically significant Conclusion HIPEMF at 0.1 Hz,4 T,in 8 pulse trains can promote NSC proliferation,perhaps through the Wnt/β-catenin signaling pathways.