Objective To investigate the effect of 14,15-epoxyeicosatrienoic acid(14,15-EET)in attenuating lipopolysaccharide(LPS)-induced acute lung injury(ALI)in mice and its mechanism.Methods Thirty-two male C57BL/6J mice aged 6-8 weeks were divid-ed into four groups according to the random number table method:control group,LPS group,LPS+ferroptosis inhibi ferrostatin-1(Fer-1)group,and LPS+14,15-EET group,each group with 8 mice.The sterile phosphate buffer solution(PBS)50 μL was used for intratracheal in-stillation in control group and 0.2 mg/mL LPS 50 μL were used for intratracheal instillation in another 3 groups,respectively.After 6 hours of in-tratracheal stimulation with LPS,Fer-1(0.8 mg/kg)was injected into the tail vein of the LPS+Fer-1 group,and 14,15-EET(100 nmol/L)was injected into the tail vein of the LPS+14,15-EET group for 16 hours,respectively.After successful modeling,lung tissues and bron-choalveolar lavage fluid(BALF)were collected from each group.The pathological changes in lung tissue of each group of mice were observed u-sing hematoxylin-eosin staining,and the wet/dry(W/D)density of the lungs was measured.The total protein concentration and total cell count in BALF of each group of mice were recorded.The expression levels of interleukin(IL)-1(3 and monocyte chemotactic protein-1(MCP-1)mRNA in mouse lung tissue were detected using real-time fluorescence quantitative polymerase chain reaction(RT-qPCR).The generation of reactive oxygen species(ROS)in lung tissue was observed by ROS staining in frozen sections.The levels of malondialdehyde and iron content in lung tissue were detected using reagent kits,respectively.The expression levels of iron death related molecules glutathione peroxidase 4(GPX4)and epoxidase 2(COX2)were detected using Western blotting.Results Compared with the control group,the lung injury score and W/D value in the LPS group were significantly increased,and the differences were statistically significant(P＜0.05);compared with the LPS group,the lung injury score and W/D value in the LPS+Fer-1 group and the LPS+14,15-EET group were significant decreased,the differences were statistically significant(P＜0.05).Compared with the control group,the total protein concentration and cell number in BALF of LPS group were significantly increased,and the expression levels of IL-1β and MCP-1 mRNA in lung tissue were significantly increased,the differences were statistically significant(P＜0.05);compared with the LPS group,the total protein concentration and cell number in BALF,and the expression levels of IL-1β and MCP-1 mRNA in lung tissue of the LPS+Fer-1 group and the LPS+14,15-EET group were significant decreased,the differences were statistically significant(P＜0.05).Compared with control group,the red fluorescence signal of ROS in the LPS group was sig-nificantly enhanced,and the levels of malondialdehyde,iron ions,and COX2 were significantly increased,while the level of GPX4 was decreased,the differences were statistically significant(P＜0.05);compared with the LPS group,the ROS red fluorescence signal in the lung tissue of the LPS+Fer-1 group and LPS+14,15-EET group was significantly reduced,and the levels of malondialdehyde,iron ions,and COX2 were signif-icantly decreased,while the levels of GPX4 were increased,the differences were statistically significant(P＜0.05).There were no statistically significant differences in the above indicators between the LPS+Fer-1 group and the LPS+14,15-EET group(P＞0.05).Conclusion 14,15-EET may alleviate LPS induced ALI in mice and exert pulmonary protective effects by inhibiting ferroptosis.
维普
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