Influence of Exogenous TGFβ_1 on the Expression of Smad2 and Smad3 in Rat Bone Marrow-derived Mesenchymal Stem Cells

Bone marrow derived mesenchymal stem cells(MSCs) have multipotential to differentiate intoosteogenic, myogenic, and adipogenic cell linea ges, depending on signals derived from the cellularenvironment. At present, MSCs have been regar ded to be one kind of preferred seed cells in the re generation of bone defects. The TGFβ1 protein ismultifunctional peptide and has a broad range ofcellular activities including the control of cell pro liferation and differentiation …     

Dynamic Expression of Tumor Necrosis Factor-α and Vascular Endothelial Growth Factor in Rat Model of Pulmonary Emphysema Induced by Smoke Exposure

In order to explore the roles of tumor necrosis factor-α(TNF-α) and vascular endothelial growth factor(VEGF) in the pathogenesis of pulmonary emphysema,male Wistar rats were randomized into group A1,group A2.5 and group A4,each with smoke exposure for 1 month,2.5 months or 4 months,respectively.Group B1,group B2.5 and group B4 were used as non smoking controls at corresponding time points.TNF-α in bronchoalveolar lavage fluid(BALF) and expression of VEGF in lung tissue was determined by ELISA or by SABC immunohistochemistry assay either.Lung slices were stained with hematoxylin and eosin(HE).Results showed that in animal with smoke exposure the mean linear interceptor(Lm),an index of pulmonary emphysema and the content of TNF-α in BALF increased gradually,on contrary,the expression of VEGF in lung tissue decreased(P<0.05).This phenomenon was not obvious in animals without smoke exposure.Lm was negatively correlated to the VEGF expression(γ=-0.81,P<0.01) and positively correlated to TNF-α concentration(γ = 0.52,P<0.004),which implies that smoke exposure decreased the expression of VEGF and increased the expression of TNF-α.It is plausible to speculate that the imbalance of TNF-α and VEGF may play an important role in the pathogenesis of smoke-induced pulmonary emphysema.     

Construction of Antisense Transforming Growth Factorβ_1 Gene and Its Effect on the Proliferation by Expression in Osteosarcoma Cells

Summary:To construct the antisense transforming growth factorβ1(TGFβ1)gene and investigatethe effect of TGFβ1 autocrine loop blockage on the proliferation of osteosarcoma cells.TGFβ1 cDNAwas cloned by RT-PCR from human osteosarcoma cells(MG-63)and inserted into pcDNA_3 to con-struct an antisense expression vector,which was dubbed pcDNA_3-TGFβ1(-).MTT was used to de-tect the proliferation of osteosarcoma cells transfected by antisense TGFβ1 gene.Our results showedthat the proliferation of the transfected osteosarcoma cells was suppressed markedly.It is concludedthat TGFβ1 autocrine loop blockage in osteosarcoma cells could inhibit cell proliferation,which mightbe helpful for gene therapy of osteosarcoma.     

Modulation of Matrix Metalloproteinase and TIMP-1 Expression by TGF-β1 in Cultured Human RPE Cells

Matrix metalloproteinases(MMPs)are a familyof zinc binding,calcium-dependent endopeptidases thatfunction by degrading extracellular matrix(ECM)components.The functional effects of these enzymesare in part controlled byinteractions withtissueinhibi-tors of metalloproteinases(TI MPs)acting as naturalMMPinhibitors.Aprecise balance between MMPandTI MPactivities may be i mportant for the integrity ofECMcomponents[1].It shows that the expression andactivity of MMPs could be regulated by va…