Effects of aspirin-triggered lipoxin A4 on lipopolysaccharide-induced acute lung injury in mice

Abstract

Objective To evaluate the effects of aspirin-triggered lipoxin A4 (ATL) on lipopolysaccharide (LPS)-induced acute lung injury in mice.Methods Thirty male SPF BALB/C mice,aged 10-12 weeks,weighing 25-30 g,were randomly assigned into 3 groups (n =10 each):normal saline group (group NS),LPS group and ATL groups.ATL 0.1 ml was injected via the tail vein 1 h after intra-tracheal instillation of 3 mg/kg LPS in LPS group.In ATL group,ATL 0.2 mg/kg was injected via the tail vein 1 h after intra-tracheal instillation of 3 mg/kg LPS.At 24 h after instillation,the mice were sacrificed.Bronchoalveolar lavage fluid was collected for determination of the total cell count,proportion of the polymorphonuclear leukocytes,proportion of the mononuclear leukocytes,and concentrations of the total protein,TNF-αt,IL-6,monocyte chemoattractant protein-1 (MCP-1) and IL-10.Lungs were removed for determination of myeloperoxidase (MPO) activity,phosphorylation of p38 mitogenactivated protein kinase (p38 MAPK),c-Jun N-terminal kinase (JNK),and extracellular signal-regulated kinase 1/2 (ERK1/2) in lung tissues and for microscopic examination.The pathological changes of lungs were scored.Results Compared with NS group,the lung injury scores,total cell counts,proportion of polymorphonuclear leukocytes,and concentrations of TNF-α,IL-6 and MCP-1 were significantly increased,and the proportion of mononuclear leukocytes was decreased in LPS and ATL groups,and IL-10 concentrations were decreased,and the concentrations of the total protein,MPO activity,and phosphorylation of p38 MAPK,JNK and ERK1/2 were significantly increased in group LPS (P ＜ 0.05),and no significant change in the concentrations of the total protein,MPO activity,phosphorylation of p38 MAPK,JNK and ERK1/2 was found in group ATL (P ＞ 0.05).Compared with LPS group,the lung injury scores,total cell counts,proportion of polymorphonuclear leukocytes and the concentrations of the total protein,TNF-α,IL-6 and MCP-1 were significandy decreased,the proportion of mononuclear leukocytes and IL-10 concentration were increased,and MPO activity and phosphorylation of p38 MAPK and JNK were decreased (P ＜ 0.05),and no significant change in the phosphorylation of ERK1/2 was found in group ATL (P ＞ 0.05).Conclusion ATL can ameliorate LPS-induced acute lung injury by inhibiting activations of p38MAPK and JNK signal pathways in mice. Key words: Lipoxins ; Aspinrin; Respiratory distress syndrome, adult