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Objective To study the effects of pulsed electromagnetic fields(PEMFs)of 15Hz and lmT on osteoblast differentiation of bone marrow mesenchymal stem cells.Methods The bone marrow mesenchymal stem cells were isolated and cultured in vitro,the third passage cells were harvested and half of them was exposed to PEMFs,another half exposed to sham PEMFs served as the control.The activity of ALP was measured.And the ex- pression of osteoblast and adipogenesis was measured with the semi-quantitative RT-PCR,adipogenic differentiation was observed with the Oil Red O Staining.Results When compared with the control,PEMFs of 15 Hz and 1 mT significantly increased the activity of ALP(P
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Objective To study the effects of 50 Hz magnetic fields on the in vitro proliferation of human osteosareoma cell line MG-63 with different cell densities.Methods Four different magnetic intensities(1 mT, 2 mT,3 roT,4 mT)were used to stimulate the cells,and the experiment was repeated with different cell densities. The method of MTT was employed to evaluate the level of proliferation.Results Fifty Hz magnetic fields signifi- cantly affected the level of proliferation of human osteosareoma cell line MG-63,and the 2 mT intensity exerted the greatest influence on it.The effects of the magnetic field differed with different cell densities.Conclusion The effect of 50 Hz magnetic fields on the in vitro proliferation of human osteosarcoma cell line MG-63 was not only relat- ed to the magnetic intensity,but also the cell density,
ABSTRACT
Objective To screen for differential expression of genes in bone marrow mesenchymal stem ceils (MSCs) stimulated by electromagnetic fields (EMFs) and to study the mechanism of differentiation of the bone mar- row MSCs induced by EMFs.Methods Mouse bone marrow MSCs were isolated and cultured in vitro.The third- passage cells were stimulated by EMFs,then the total RNA was extracted,purified to cDNA and reversely transcribed to yield a cRNA probe.The cRNA probes from stimulated and control cells were labelled with Cy5 and Cy3,respec- tively.The two samples were hybridized with a mouse oligo microarray,and the hybridization signals were scanned. The reverse transcriptase polymerase chain reaction (RT-PCR) was used to identify the interesting genes:Duspl and Rabl.Results A total of 153 differentially expressed genes were found comparing the stimulated group and the control group.There were 74 up-regulated genes and 79 down-regulated genes in the stimulated group.Semi-quantita- tive RT-PCR confirmed that the Duspl and Rabl mRNA expression levels of the stimulated group were up-regulated. Conclusion The gene expression profiles of the bone marrow MSCs were altered after EMF exposure.The genes are involved in cell proliferation and differentiation,transcription control,metabolism and response to stress.These re- sults provide deeper insight into the mechanism of differentiation of the bone marrow MSCs.