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Objective To study the effect of high mobility group box B1(HMGB1)gene knockout on alleviating a-cute lung injury and inhibiting toll-like receptor 4(TLR4)/nuclear factor-KB(NF-κB)pathway of sepsis mice.Methods Wild-type(WT)mice were divided into WT-Sham group and WT-model group,and HMGB1 knockout(KO)mice were divided into KO-sham group and KO-model group.Sepsis ALI model was established by cecal ligation and perforation in WT-model group and KO-model group.Sham operation was performed in WT-Sham group and KO-Sham group.24 h after modeling,the partial pressure of arterial oxygen(PaO2)was detected,oxy-genation index(OI)was calculated,pathological changes of lung tissue were detected and lung injury score was calculated,the concentrations of tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1 β),interleukin-6(IL-6),reactive oxygen species(ROS),malondialdehyde(MDA),superoxide dismutase(SOD),in serum and lung tissues and the expression of HMGB1,TLR4 and nuclear NF-κB in lung tissues were detected.Results The PaO2,OI and the concentration of SOD in serum and lung tissue of WT-model group were lower than those of WT-Sham group,the lung injury scores,the concentrations of TNF-α,IL-1 β,IL-6,ROS and MDA in serum and lung tissue,and the expression levels of HMGB1,TLR4 and nuclear NF-κB in lung tissue were higher than those in WT-Sham group(P＜0.05).HMGB1 was not expressed in lung tissue of KO-model group,and the concentrations of PaO2,OI and the concentration of SOD in serum and lung tissue of KO-model group were higher than those of WT-model group,the lung injury scores,the concentrations of TNF-α,IL-1β,IL-6,ROS and MDA in serum and lung tissue,and the expression levels of TLR4 and nuclear NF-κB in lung tissue were lower than those of the WT-model group(P＜0.05).Conclusion HMGB1 gene knockout alleviates acute lung injury of sepsis mice,the re-lated molecular mechanism may be the inhibition of TLR4/NF-κB pathway mediated inflammation and oxidative stress.
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BACKGROUND:It is of great significance to find new diagnostic markers of the disease and molecular targets for the treatment of the disease and the alleviation of organ injury.Ferroptosis is a newly discovered form of cell death.Overactivation of ferroptosis in animal models of sepsis is associated with the activation of inflammatory response and the injury of the liver,heart,kidney and other important organs,but the relationship between ferroptosis and bloodstream infection is not very clear. OBJECTIVE:To study the changes and biological significance of ferroptosis in a mouse model of blood stream infection induced by different bacteria. METHODS:Blood stream infection models induced by gram negative bacteria Escherichia coli,Klebsiella pneumoniae and gram positive bacteria Staphylococcus aureus and Enterococcus faecalis were established in SPF-grade ICR male mice,with 42 mice in each group.The mRNA expression levels of ferroptosis marker genes transferrin receptor 1 and glutathione peroxidase 4 in the liver,myocardium and kidney were detected at 0.5,1,3,6,12,24 and 48 hours after modeling.Another 18 SPF-grade ICR male mice were selected and randomly divided into dimethyl sulfoxide(DMSO)control group,DMSO+Klebsiella pneumoniae group,and Ferrostatin-1+Klebsiella pneumoniae group,with 6 mice in each group.In the latter two groups,animal models of Klebsiella pneumoniae bloodstream infection were established by tail vein injection of Klebsiella pneumoniae suspension,and 5 mg/kg Ferrostatin-1 and an equal dose of DMSO were given intraperitoneally 1 hour prior to the modeling of bloodstream infection,respectively.Serum levels of alanine aminotransferase,aspartate aminotransferase,blood creatinine,blood urea nitrogen,phosphocreatine kinase isoenzyme,lactate dehydrogenase,and mRNA expression levels of ferroptosis marker genes in various tissues were assayed at 6 hours after modeling. RESULTS AND CONCLUSION:After bloodstream infection modeling,the mRNA expression levels of transferrin receptor 1 in the liver,myocardium and kidney of bloodstream infection mice with different bacteria increased first and then decreased;and the mRNA expression level of glutathione peroxidase 4 decreased first,then increased,and reached the peak at 6 hours after modeling.The changes in transferrin receptor 1 and glutathione peroxidase 4 mRNA levels in bloodstream infection mice induced by gram-negative bacteria were more significant than those in blood stream infection mice induced by gram-positive bacteria,especially in bloodstream infection mice induced by Klebsiella pneumoniae.At 6 hours after bloodstream infection induced by Klebsiella pneumoniae,the levels of alanine aminotransferase,aspartate aminotransferase,serum creatinine,blood urea nitrogen,creatine phosphate kinase isoenzyme,lactate dehydrogenase in mice were significantly increased.Before modeling,Ferrostatin-1 intervention significantly reduced the levels of alanine aminotransferase,aspartate aminotransferase,serum creatinine,blood urea nitrogen,creatine phosphate kinase isoenzyme,and lactate dehydrogenase.All these findings indicate that the activation of ferroptosis in bloodstream infection mice induced by different bacteria is obvious,and the activation of ferroptosis in bloodstream infection mice induced by gram-negative bacteria is more obvious.Inhibition of iron death significantly attenuates liver,myocardial,and kidney injury in the mouse model of bloodstream infection induced by Klebsiella pneumoniae.
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Objective:To construct a prognostic model for severe acute pancreatitis (SAP) based on CT scores and inflammatory factors, and to evaluate its efficacy.Methods:128 patients with SAP diagnosed admitted to the First Hospital Affiliated to Hebei North College from March 2019 to December 2021 were enrolled and given Ulinastatin combined with continuous blood purification therapy. The levels of C-reactive protein (CRP), procalcitonin (PCT), interleukins (IL-6, IL-8), tumor necrosis factor-α (TNF-α), and D-dimer were measured before and on the third day of treatment. An abdominal CT was performed on the third day of treatment to assess the modified CT severity index (MCTSI) and extra-pancreatic inflammatory CT score (EPIC). Patients were divided into the survival group ( n = 94) and the death group ( n = 34) according to the 28-day survival prognosis after admission. The risk factors for the SAP prognosis were analyzed using Logistic regression, which was then used to build nomogram regression models. The value of the model was evaluated using the concordance index (C-index), calibration curves and decision curve analysis (DCA). Results:Before treatment, the levels of CRP, PCT, IL-6, IL-8 and D-dimer in the death group were higher than those in the survival group. After treatment, the levels of IL-6, IL-8 and TNF-α in the death group were higher than those in the survival group. MCTSI and EPIC scores in the survival group were lower than those in the death group. Logistic regression analysis shows that, pre-treatment CRP > 140.70 mg/L, D-dimer > 2.00 mg/L, and post-treatment IL-6 > 31.28 ng/L, IL-8 > 31.04 ng/L, TNF-α > 31.04 ng/L, and MCTSI > 8 points were all independent risk factors for SAP prognosis [odds ratios ( OR) and 95% confidence intervals (95% CI) were 8.939 (1.792-44.575), 6.369 (1.368-29.640), 8.546 (1.664-43.896), 5.239 (1.108-24.769), 4.808 (1.126-20.525), 18.569 (3.931-87.725), all P < 0.05]. Model 1 (consisting of pre-treatment CRP, D-dimer, and post-treatment IL-6, IL-8 and TNF-α) had a lower C-index than that model 2 (consisting of pre-treatment CRP, D-dimer, and post-treatment IL-6, IL-8 and TNF-α, and MCTSI; 0.988 vs. 0.995). The mean absolute error (MAE) and mean square error (MSE) of model 1 (0.034, 0.003) were higher than those of model 2 (0.017, 0.001). When the threshold probability was in the range of 0-0.66 or 0.72-1.00, the net benefit of model 1 was lower than that of model 2. When the threshold probability was in the range of 0.66-0.72, the net benefit of model 1 was higher than that of model 2. In addition, model 2 had a higher C-index than acute physiology and chronic health evaluationⅡ (APACHE Ⅱ) and bedside index of acute pancreatitis severity (BISAP, 0.995 vs. 0.833, 0.751). Model 2 had a lower MAE (0.017) and MSE (0.001) than APACHEⅡ (0.041, 0.002). Model 2 had a lower MAE than BISAP (0.025). Model 2 had a higher net benefit than both APACHEⅡ and BISAP. Conclusion:The prognostic assessment model of SAP consisting of pre-treatment CRP, D-dimer, and post-treatment IL-6, IL-8 and TNF-α, and MCTSI has high discrimination, precision and clinical application value, and is superior to APACHEⅡ and BISAP.