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.
Bone Marrow Cells/*cytology ; Cell Differentiation ; Down-Regulation ; Electromagnetic Fields ; Gene Expression Profiling ; Gene Expression Regulation ; Mesenchymal Stem Cells/*cytology ; Nucleic Acid Hybridization ; Oligonucleotide Probes/chemistry ; Osteogenesis/*genetics ; RNA, Complementary/metabolism ; Reverse Transcriptase Polymerase Chain Reaction

Objective To study the influence of pulsed electromagnetic fields on the expression of type I collagen by bone marrow mesenchymal stem cells and it's mechanism. Methods The bone marrow mesenchymal stem cells of SD rats were isolated and cultured in vitro.The third passage cells were harvested and exposed to pulsed electromagnetic fields(PEMFs)at 15 Hz and 1 mT 8 h/d for 3 days.A semi-quantitative RT-PCR technique was used to measure the type I collagen mRNA expression;ELISA and immunohistochemitistry techniques were used to measure type I collagen expression.Inhibitors and promoters of the cAMP-dependent protein kinase A(cAMP-PKA)pathway were added.After the cAMP-PKA pathway had been inhibited or promoted,the effects of the PEMF on type I collagen expression were measured again using ELISA and immunohistoehemistry.Results PEMFs at 15 Hz and 1 mT induced significant promotion of the expression of type I collagen(P≤0.01)in comparison with the controls. The type I collagen expression was reduced when the cAMP-PKA pathway inhibitor H-89 was added,and raised when the promoter 8-Br-cAMP was added.Conclusion PEMFs at 15 Hz 1 mT can promote type I collagen expression of bone marrow mesenchymal stem cells.and the effect is correlated with the cAMP-PKA pathway.

Objective To investigate the effects of an electromagnetic field on the extra-cellularly regulated kinase(ERK)signalling pathway and to determine the impact of electromagnetic activation on osteogenic proliferation and differentiation in rat bone marrow mesenchymal stem cells.Methods Rat bone marrow mesenchymal stem cells were isolated and cultured in vitro.The third-passage cells were divided into 4 groups(Control,PD98059,EMF and EMF+PD98059).Western blotting Was used to detect the activation of the ERK signal pathway after exposure to an electromagnetic field.MTT assay Was used to determine the activation of proliferation in the celb in the different groups.The cells' alkaline phosphatase activities were also detected. Results (1)The ERK signal pathway in these rat bone marrow mesenchymal stem cells was activated after exposure to a 15 Hz.1 mT,sine wave form electromagnetic field for 5 min.Activation remained high for at least 1 h.PD98059 can effectively block the activation of the ERK signal pathway.(2)Cell proliferation was promoted after exposure to the electromagnetic field,and this effect could be significantly inhibited by PD98059.(3)Alkaline phosphatase was significantly elevated in these bone marrow mesenchymal stem cells after exposure to the electromagnetic field.The activation in the EMF+PD98059 group Was slightly greater than in the EMF group.Conclusion Electromagnetic fields of 15 Hz and 1 mT can activate the ERK signal pathway and alter proliferation and osteogenic differentiation in the bone marrow mesenchymal stem cells of rats.

Background Researches indicated that etiology and epidemiology of pertussis toxin (PTX)dependent experimental autoimmune uveoretinitis(EAU)model are very different with human uveoretinitis owing to the influence of PTX on immune.Our previous study has established lipopolysaccharide (LPS),an endotoxin,which instesad of PTX,mediated EAU model.However,the exact roles of LPS and PTX in EAU still remained unclear.Objective This study was to investigate the roles of LPS and PTX in EAU model.Methods Twenty SPF C57BL/6(H-2b) mice were assigned to 0 d-PTX-EAU group,7 d-PTX-EAU group,0 d-LPS-EAU group and 7 d-LPS-EAU group using random number table method.The mice were immunized with interphotoreceptor retinoid-binding protein 1-20(IRBP 1-20) emulsified in complete Freund adjuvant (CFA),and concurrently with or on day 7 postimmunization,LPS or PTX was injected in the footpad or intraperitoneally respectively.Delayed-type hypersensitivity (DTH) of the mice was evaluated by measuring the ear thickness 48 hours after IRBP was injected into the ear pinna,and lymphocyte proliferation was assessed by tritiated thymidine uptake.Retinal histopathological examination was performed and scored based on criteria of Caspi.The use and care of experimental animals complied with Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results Serious infiltration of inflammatory cells,disorder of entire retinal structure and retinal folds were seen in the mice of the 0 d-PTX-EAU group and 7 d-LPS-EAU group on 21 days after injection of PTX or 14 days after injection of LPS,and severe vitritis and a few granuloma-like lesions were found in the 0 d-PTX-EAU group.However,only mild vasodilatation or less retinal folds were found in the 7 d-PTX-EAU group and 0 d-LPS-EAU group.The pathological scores in the mice of the 0 d-PTX-EAU group and 7 d-LPS-EAU group were higher than those of the 7 d-PTX-EAU group and 0 d-LPS-EAU group (all at P ＜ 0.05).The ear thickness was (62.600 ± 3.362) μm,(60.000±2.345) μm,(30.400± 1.817) μm and (32.800 ± 1.643) μm in the 0 d-PTX-EAU group,7 d-PTX-EAU group,0 d-LPS-EAU group and 7 d-LPS-EAU group,showing a significantly difference among the 4 groups (Fgroup =259.751,P=0.000),and the ear thicknesses of 0 d-PTX-EAU group and 7 d-PTX-EAU group were significantly higher than those of the 0 d-LPS-EAU group and 7 d-LPS-EAU group (all at P＜0.05).The lymphocyte proliferation was strongly enhanced in PTX-EAU groups,and the radiation count per minute (cpm) was (16 150.000±799.218)/min and (16 120.000±729.383)/min in the 0 d-PTX EAU group and 7 d-PTX EAU group,and (8 348.000±258.979)/min and (8 540.000±81.548)/min in the 0 d-LPS EAU group and 7 d-LPS EAU group respectively,with a significant difference among the PTX-EAU groups and LPS-EAU groups (Fgroup =316.978,P=0.000).Conclusions LPS and PTX play different roles during the EAU formation.LPS may be involved in the breakdown of blood-retina barriers (BRB).

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.