Effects of acute lung injury on apoptosis in rat splenic T cells and the interventional effect of Yifei Jianpi formula
Objective To observe splenic T cell apoptosis and XIAP-associated factor 1(XAF1),FAS,and tumor necrosis factor(TNF)-α protein expression levels in rats with acute lung injury(ALI),and to determine their roles in the protective effect of Yifei Jianpi formula.Methods Sixty male specific pathogen-free SD rats were divided randomly into blank,model,positive control,and high-,medium-,and low-dose Yifei Jianpi formula groups.Rats in the positive control group were given 0.5 g/kg dexamethasone by gavage,and rats in the high-,medium-,and low-dose Yifei Jianpi formula groups were given 12,6,and 3 g/kg Yifei Jianpi formula by gavage,respectively.Rats in the model and blank groups were given equal amounts of saline by gavage.All medications were administered once a day for 14 days.Lung function testing was carried out in all rats.We observed the imaging characteristics of the lungs and changes in the organ index and lung tissue wet/dry weight(W/D)in each group,and detected the pathological changes in lung tissues by hematoxylin-eosin staining.Splenic T-cell subpopulations(CD4+/CD8+)and apoptosis of splenic T-cells were detected by flow cytometry and XAF1,FAS,and TNF-α protein expression levels in the spleen were detected by Western Blot.Results Rats in the model group showed reduced lung function,decreased spleen and thymus organ indexes,and significantly higher W/D of lung tissue(P<0.01).In addition,they had inflammatory exudation and alveolar rupture in the lung tissue,accompanied by thickening of the lung texture and large areas of ground-glass shadows,with a significant decrease in T-cell subsets(CD4+/CD8+)and significant increases in XAF1,FAS,and TNF-α proteins,and in the rate of T-cell apoptosis(P<0.01).Yifei Jianpi formula significantly reduced the W/D spleen of rat lung tissues,significantly increased the thymus organ index(P<0.05,P<0.01)and the T-cell subpopulation(CD4+/CD8+),and significantly decreased the protein expression levels of XAF1,FAS,and TNF-α,and the T-cell apoptosis rate(P<0.05,P<0.01).Conclusions ALI induced up-regulation of XAF1,FAS,and TNF-α protein expression and T-cell apoptosis in the spleen of rats,and Yifei Jianpi formula may protect against ALI by down-regulating these factors.