Effect Of Tranfoming Growth Factor Beta-1 On Human Alveolar Epithelial Type II Cell Line A549 In Vitro

Objective:This experiment was designed to investigate the role of the recombinal human tranfoming growth factor beta-1(rhTGF-β1)on human an alveolar epithelial typeⅡcell line A549,to understand more about the possible pathogenesy of idiopathic pulmonary fibrosis.Methods:cultured A549 cells were treated at different concentration,the morphology change observed under phase-contrast microscopy;the expression of epithelial phenotypic markers including E-Cadherin(E-Cad) and the expression of mesenchymal phenotypic markers including fibronectin EDA(Fn-EDA)were analysised of cell lysates by Western blotting and inmmunofluorescene assay after 48h.the expression of markers of fibrogenesi collegens typeⅠalso evaluated by RT-PCR and inmmunofluorescene assay.Results:1 The data showed that TGF-β1-treated cells morphological shape became from pebble-like shape and cell-cell adhesion to decrease in cell-cell contacts and adopt a more elongated,with TGF-β1 consentrions increased.when the consentrations was 5ng/ml of TGF-β1,this change became sharply.2 A549 cells were incubeted with different concentrations of TGF-β1,the effect about cells proliferation was detected after 24h and 48h by MTT.The results was TGF-β1 no effect about A549 cells proliferation(p＞0.05).3 TGF-β1 decreased the epithelial phenotype marker E-Cad,as each different concentrations groups compared with the model(p＜0.01).the 5ng/ml groups compared with the 1ng/ml,the protein expression of E-cad was lower(p＜0.05).4 TGF-β1 enhanced significantly the expression of mesenchymal phenotypic marker Fn-EDA,as each different concentrations groups compared with the model(p＜0.01),the 5ng/ml groups compared with the 1ng/ml,the protein expression of Fn-EDA was higher(p＜0.01).5 TGF-β1 significantly(P＜0.01)stimulated the expression of collagens typeⅠwhen 5ng/ml TGF-β1groups compared with the model groups,as detected by RT-PCR and inmmunofluorescene assay of the cell layer.concolusion:our studys shows that TGF-β1 induced A549 alveolar epithelial typeⅡcells to undergo EMT,support the concept of EMT in lung epithelial cells.