Mechanism Of Regulates NETs To Inhibit Pyrodeath And Relieve Lung Injury In Sepsis

Objective: Neutrophil Extracellular Traps(NETs)are a network structure formed by neutrophils activated under specific stimulation,which plays a crucial role in the inflammatory response of sepsis-induced lung injury.NETs have a strong elimination effect on pathogens within a specific range.Still,studies have shown that sustained high levels of HMGB1 released by NETs can up-regulate GSDMD(Gasdermin D)protein through the RAGE-Cat B-ASC-Caspase1 signaling pathway.However,GSDMD protein can lead to pyroptosis,resulting in a strong inflammatory response that aggravates septic lung injury.Studies have found that glabridin can be anti-inflammatory by inhibiting the phosphorylation of p38 mitogen-activated protein kinase(p38MAPK),reducing the production of inflammatory cytokines IL-1β and IL-18,thereby reducing the occurrence of tissue damage,and the p38 MAPK pathway is also an important generation signal of NETs.However,there is no relevant study on whether glabridin has a regulatory effect on NETs formation and pyroptosis in patients with sepsis-induced lung injury.Therefore,this study aimed to investigate the changes in NETs and pyroptosis in acute lung injury under the intervention of glabridin,to provide a theoretical basis for treating sepsis-induced lung injury.Methods: Twenty-four male Wistar rats were divided into three groups according to the method of random number table,eight in each group: control group(Ctrl),sepsis group(CLP),glabridin group(CLP+GLA).The sepsis group established a sepsis rat model by cecal ligation and puncture(CLP);after CLP in the glabridin group,glabridin(30 mg/kg)was administered by gavage.The control group underwent cecal exploration and only closed the abdomen after cecal turnover.After 12 hours,plasma、alveolar lavage fluid and lung tissue samples were taken for detection.Then,protein content of the alveolar lavage fluid was determined;The wet / dry weight(W / D)ratio of the lung tissue was determined;The pathological changes in lung tissue were observed after hematoxylin-eosin(H & E)staining.The levels of NETs marker MPO-DNA complex and related inflammatory factors IL-18 and IL-1β in plasma were detected by enzyme-linked immunosorbent assay(ELISA).Western blot detected the changes of pyroptosis protein Caspase-1and Cleaved-caspase-1 in rats’ lung tissue.Results: 1.The total protein concentration of alveolar lavage fluid was significantly higher in the sepsis group compared with the control group(P<0.05),and it was decreased in the glabridin group compared with the sepsis group(P<0.05).2.Significant aggravation of pulmonary edema in the sepsis group,and the glabridin group reduced pulmonary edema compared with the sepsis group.3.The pathological results of lung tissue under the light microscope showed that:In the control group,the lung tissue structure was normal,and the alveoli were clear;in the sepsis group,the alveolar wall was widely thickened,and inflammatory cells were significantly infiltrated;the lung tissue injury in glabridin group was significantly reduced compared with sepsis group.4.The results of the ELISA assay showed that: The levels of NETs marker MPO-DNA complex and related inflammatory factors IL-18 and IL-1 β of the sepsis group were significantly higher than those in the control group(P <0.05),The level of NETs marker MPO-DNA complex and related inflammatory factors IL-18 and IL-1 β in glabridin group were lower than those in sepsis group(P < 0.05)5.Western blot Technical results showed that the expression of Caspase-1 and Cleaved-caspase-1 protein positive signal was significantly enhanced in the lung tissue of the rats in the sepsis group compared with the control group;the distribution of Caspase-1 positive cells in the lung tissue of the glabridin group was similar to that of the control group,and the expression of Cleaved-caspase-1 positive signal was higher than that of the control group.Conclusions: During sepsis-induced lung injury,NETs and pyroptosis in the lung tissue of rats increased,resulting in a storm of inflammatory factors,which aggravated inflammatory lung injury.The anti-inflammatory drug glabridin can inhibit the production of NETs and effectively reduce the production of pyroptosis in lung tissue,thereby reducing inflammatory injury in lung tissue.