RESUMO
The use of electromagnetic fields (EMFs) to treat nonunion fractures developed from observations in the mid-1900s. Whether EMF directly regulates the bone marrow mesenchymal stem cells (MSCs), differentiating into osteoblasts or adipocytes, remains unknown. In the present study, we investigated the roles of sinusoidal EMF of 15 Hz, 1 mT in differentiation along these separate lineages using rat bone marrow MSCs. Our results showed that EMF promoted osteogenic differentiation of the stem cells and concurrently inhibited adipocyte formation. EMF increased alkaline phosphatase (ALP) activity and mineralized nodule formation, and stimulated osteoblast-specific mRNA expression of RUNX2, ALP, BMP2, DLX5, and BSP. In contrast, EMF decreased adipogenesis and inhibited adipocyte-specific mRNA expression of adipsin, AP-2, and PPARgamma2, and also inhibited protein expression of PPARgamma2. These observations suggest that commitment of MSCs into osteogenic or adipogenic lineages is influenced by EMF.
Assuntos
Diferenciação Celular/efeitos da radiação , Campos Eletromagnéticos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos da radiação , Osteoblastos/citologia , Osteogênese/efeitos da radiação , Adipócitos/citologia , Adipogenia/efeitos da radiação , Animais , Células da Medula Óssea/citologia , Diferenciação Celular/fisiologia , Células Cultivadas , Regulação para Baixo , Feminino , Expressão Gênica/efeitos da radiação , Masculino , PPAR gama/biossíntese , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
In order to identify the differentially expressing gene of bone marrow mesenchymal stem cells (MSCs) stimulated by electromagnetic field (EMF) with osteogenesis microarray analysis, the bone marrow MSCs of SD rats were isolated and cultured in vitro. The third-passage cells were stimulated by EMFs and total RNA was extracted, purified and then used for the synthesis of cDNA and cRNA. The cRNA of stimulated group and the control group was hybridized with the rat oligo osteogenesis microarray respectively. The hybridization signals were acquired by using X-ray film after chemiluminescent detection and the data obtained were analyzed by employing the web-based completely integrated GEArray Expression Analysis Suite. RT-PCR was used to identify the target genes: Bmp1, Bmp7, Egf and Egfr. The results showed that 19 differentially expressing genes were found between the stimulated group and the control group. There were 6 up-regulated genes and 13 down-regulated genes in the stimulated group. Semi-quantitative RT-PCR confirmed that the expressions of Bmp1, Bmp7 mRNA of the stimulated group were up-regulated (P<0.05) and those of Egf, Egfr were down-regulated (P<0.05). It was suggested that the gene expression profiles of osteogenesis of the bone marrow MSCs were changed after EMF treatment. It is concluded that the genes are involved in skeletal development, bone mineral metabolism, cell growth and differentiation, cell adhesion etc.
Assuntos
Células da Medula Óssea/citologia , Regulação da Expressão Gênica , Células-Tronco Mesenquimais/citologia , Osteogênese/genética , Animais , Diferenciação Celular , Regulação para Baixo , Campos Eletromagnéticos , Perfilação da Expressão Gênica , Camundongos , Hibridização de Ácido Nucleico , Sondas de Oligonucleotídeos/química , RNA Complementar/metabolismo , Ratos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In order to identify the differentially expressing gene of bone marrow mesenchymal stem cells (MSCs) stimulated by electromagnetic field (EMF) with osteogenesis microarray analysis, the bone marrow MSCs of SD rats were isolated and cultured in vitro. The third-passage cells were stimulated by EMFs and total RNA was extracted, purified and then used for the synthesis of cDNA and cRNA. The cRNA of stimulated group and the control group was hybridized with the rat oligo osteogenesis microarray respectively. The hybridization signals were acquired by using X-my film after chemiluminescent detection and the data obtained were analyzed by employing the web-based completely integrated GEArray Expression Analysis Suite. RT-PCR was used to identify the target genes: Bmpl, BmpT, Egf and Egfr. The results showed that 19 differentially expressing genes were found between the stimulated group and the control group. There were 6 up-regulated genes and 13 down-regulated genes in the stimulated group. Semi-quantitative RT-PCR confirmed that the expres- sions of Bmpl, Bmp7 mRNA of the stimulated group were up-regulated (P<0.05) and those of Egf, Egfr were down-regulated (P<0.05). It was suggested that the gene expression profiles of osteogene- sis of the bone marrow MSCs were changed after EMF treatment. It is concluded that the genes are involved in skeletal development, bone mineral metabolism, cell growth and differentiation, cell ad- hesion etc.
