Objective To study the differences in gene expression in A549 cells transfected with Forkhead box protein O1(FOXO1),and provide clues to further exploring the mechanism of FOXO1 in acute lung injury. Methods After using TNF-α to stimulate A549 cells,the eukaryotic expression vector GV230-FOXO1 was transfected into A549 cells by using lipofectamine transfection reagent.The RNA was isolated and differentially expressed genes were screened with high-throughout DNA microarray. Results The eukaryotic expression vector GV230-FOXO1 was successfully constructed and verified.High quality mRNA was isolated and prepared for microarray screening,which passed RNA quality control.The DNA microarray data indicated that 317 genes were up-regulated and 237 genes were down-regulated in A549 cells transfected with FOXO1.The function of these differentially expressed genes involved in many aspects,such as proliferation,apoptosis and differentiation. Conclusions Differentially expressed genes in A549 cells transfected with FOXO1 can be successfully screened by using DNA microarray.FOXO1 may influence the progression of the disease by changing the level of cell proliferation,apoptosis and differentiation in acute lung injury.
ObjectiveTo investigate the mechanism of lung tissue apoptosis in LPS-induced mice ARDS via TNF-α neutralization. MethodsThirty-six mice were randomly divided into a control group,a LPS group,and TNF-α neutralization group.LPS(5 mg/kg) was intratracheally nebulized to induce ARDS in the LPS group and the TNF-α neutralization group.Twenty-four hours before LPS treatment,etanercept (0.4 mg/kg) was abdominal injected to the mice in the TNF-α neutralization group.Mice were sacrificed 2 hours after LPS treatment.PCR were used to detected the expression of NF-κB p65,Bax and Bcl-2 in lung tissue.Western blot were used to detected protein level of NF-κB p65,Erk1/2 and their phosphorylation and Bax,Bcl-2.The lung dry-to-wet ratio was measured.The lung histological changes were evaluated by HE staining. ResultsActivation level of NF-κB p65 and Erk1/2 was elevated,the ratio of Bcl-2 and Bax was decreased in the LPS group(P<0.05).After TNF-α neutralization,the activation level of NF-κB p65 and Erk1/2 were reduced,the ratio of Bcl-2 and Bax was increased (P<0.05).Compared with the LPS group,the lung dry-to-wet ratio and lung injury semi-quantitative score were significantly decreased in the TNF-α neutralization group (P<0.05). ConclusionTNF-α neutralization can suppress lung injury in LPS-induced ARDS mice by inhibiting activation of NF-κB p65 and Erk1/2,increasing the ratio of Bcl-2 and Bax ratio,and eventually reducing apoptosis.