Nuclear Factor Erythroid 2 Related Factor 2 Alleviates Seawater Exposure-Induced Lung Injury By Inhibition Of Ferroptosis

Drowning-induced accidental injuries and deaths are important public health issues and one of the leading causes of accidental deaths worldwide.Acute lung injury is a common complication of drowning.Oxidative stress injury plays a key role in the process of acute lung injury.Nuclear factor erythroid 2 related factor 2(Nrf2)is an important oxidative stressrelated transcription factor that mediates the expression of more than 100 oxidative stressrelated genes.Ferroptosis is a new type of cell death characterized by accumulation of ROS and iron-dependent lipid peroxidation.Numerous studies have shown that Nrf2 has a regulatory effect on ferroptosis.Previous studies have shown that up-regulation of Nrf2 expression in lung injury caused by drowning has protective effects,but the mechanism of Nrf2 in lung injury caused by drowning is unclear.The purpose of this study was to investigate whether ferroptosis is involved in drowning-induced lung injury and the role of ferroptosis in the relief of lung injury by Nrf2.In this study,a mouse lung epithelial cell line MLE-12 was used to establish a cell injury model by seawater stimulation.After seawater treatment,the expression of Nrf2 mRNA and protein in MLE-12 cells increased,and the expression of ferroptosis marker Ptgs2 mRNA increased.After treatment with ferroptosis inhibitor Fer-1,cell damage was alleviated,ROS production was reduced,and lipid peroxide accumulation was reduced.The results of glutathione(GSH),malondialdehyde(MDA)and superoxide dismutase(SOD)also showed that Fer-1 inhibited ferroptosis and reduced cell damage,and ferroptosis participated in the process of cell damage caused by seawater.MLE-12 cells were further treated with Nrf2 agonist dimethyl fumarate(DMF)and inhibitor ML385.DMF up-regulates Nrf2 expression,alleviates cell damage,reduces ROS production and lipid peroxide accumulation,and reduces mitochondrial damage.In addition,the Nrf2 inhibitor ML385 reversed the effect of DMF,indicating that Nrf2 inhibited ferroptosis and reduced cell damage caused by seawater stimulation.This study applied seawater drowning mouse lung injury model.Fer-1 was treated with ferroptosis inhibitor Fer-1.The lung morphology,wet / dry ratio,GSH and MDA showed that ferroptosis participates in the lung injury process of mice and inhibits ferroptosis reduction.Lung injury in mice caused by drowning.Lung morphology,lung injury score,lung wet / dry ratio,GSH,and MDA showed that DMF promotes Nrf2 expression reduced lung injury in mice.Moreover,the decrease of Ptgs2 mRNA level indicates that the DMF promotes Nrf2 expression,inhibits ferroptosis,and reduces drowning lung injury.In order to clarify the role of Nrf2 in drowning lung injury in mice,this study was validated using Nrf2 gene knockout mice.Lung morphology,pathological injury score,wet/dry ratio,GSH and MDA results showed that knockout of Nrf2 exacerbated lung injury in mice caused by seawater drowning.Ptgs2 mRNA results showed that ferroptosis levels in the Nrf2 knockout group were significantly higher than those in the control group.Taken together,this study confirms that ferroptosis participates in the process of lung injury caused by seawater drowning at the cellular and in vivo levels.DMF promotes Nrf2 expression can inhibit ferroptosis and reduce lung damage caused by seawater drowning.