Changes of FLI-1 protein expression in mice with pulmonary endothelial barrier dysfunction following acute lung injury induced by lipopolysaccharide

Abstract

Objective: To observe changes of Friend leukemia virus integration 1 (FLI-1) protein expression of pulmonary tissue in mice with pulmonary endothelial barrier dysfunction following acute lung injury (ALI) induced by lipopolysaccharide (LPS). Methods: The mouse model of ALI was established by injection of LPS (7.5 mg/kg, i.p. ). At 0 h, 12 h, 24 h and 48 h after LPS injection, pulmonary microvascular endothelial permeability and lung wet/dry weight ratio (W/D) were assessed. The contents of TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF) were detected by ELISA method. The protein levels of FLI-1 and Src protein tyrosine kinase (SRC) were analyzed by Western blotting.Results: ①Pulmonary microvascular endothelial permeability at 12 h and 24 h were significantly higher than those of 0 h by 74.3% and 162.4%, respectively, while that of 48 h was lower than that of 24 h by 27.0% (P＜0.05). The W/D at 12 h and 24 h were significantly higher than those of 0 h by 50.1% and 122.9%, respectively, while that of 48 h was lower than that of 24 h by 10.7% (P＜0.05). ②The contents of IL-6 and TNF-α in BALF at 12 h and 24 h were significantly higher than those of 0 h, while those of 48 h were significantly lower than those of 24 h by 28.3% and 21.6% (P＜0.05), respectively. ③The protein level of FLI-1 in lung at 12 h and 24 h were down-regulated than those of 0 h by 20.4% and 56.9%, respectively, while that of 48 h was up-regulated than that of 24 h by 18.2% (P＜0.05). The protein level of SRC in lung at 12 h and 24 h were up-regulated than those of 0 h by 76.8% and 176.7%, respectively, while that of 48 h was down-regulated than that of 24 h by 33.4% (P＜0.05).④Same as the protein level of FLI-1 with the protein level of SRC in lung, pulmonary microvascular endothelial permeability was significantly negative correlated with the protein level of FLI-1 in lung, while it was significantly positive correlated with the protein level of SRC (P＜0.01). Conclusion: FLI-1 participates in the pathological proceeding of pulmonary endothelial barrier dysfunction following ALI induced by LPS.