Iron Overload-Dependent Ferroptosis Aggravates LPS-Induced Acute Lung Injury by Impairing Mitochondrial Function.

Ferroptosis is a newly proposed form of programmed cell death that is iron-dependent and closely linked to oxidative stress. Its specific morphological changes include shrunken mitochondria, increased density of mitochondrial membrane, and rupture or disappearance of mitochondrial cristae. The main mechanism of ferroptosis involves excessive free iron reacting with membrane phospholipids, known as the Fenton reaction, resulting in lipid peroxidation. However, the role of iron in acute lung injury (ALI) remains largely unknown. In this study, LPS was instilled into the airway to induce ALI in mice. We observed a significant increase in iron concentration during ALI, accompanied by elevated levels of lipid peroxidation markers such as malonaldehyde (MDA) and 4-hydroxynonenal (4-HNE). Treatment with the iron chelator deferoxamine (DFO) or ferroptosis inhibitor ferrostatin-1 (Fer-1) reversed lipid peroxidation and significantly attenuates lung injury. Similarly, DFO or Fer-1 treatment improved the cell survival significantly in vitro. These results demonstrated that ferroptosis occurs during ALI and that targeting ferroptosis is an effective treatment strategy. Interestingly, we found that the increased iron was primarily concentrated in mitochondria and DFO treatment effectively restored normal mitochondria morphology. To further confirm the damaging effect of iron on mitochondria, we performed mitochondrial stress tests in vitro, which revealed that iron stimulation led to mitochondrial dysfunction, characterized by impaired basal respiratory capacity, ATP production capacity, and maximum respiratory capacity. MitoTEMPO, an antioxidant targeting mitochondria, exhibited superior efficacy in improving iron-induced mitochondrial dysfunction compared to the broad-spectrum antioxidant NAC. Treatment with MitoTEMPO more effectively alleviated ALI. In conclusion, ferroptosis contributes to the pathogenesis of ALI and aggravates ALI by impairing mitochondrial function.

Edaravone alleviated allergic airway inflammation by inhibiting oxidative stress and endoplasmic reticulum stress.

Oxidative stress and endoplasmic reticulum stress (ERS) was associated with the development of asthma. Edaravone (EDA) plays a classical role to prevent the occurrence and development of oxidative stress-related diseases. Herein, we investigated the involvement and signaling pathway of EDA in asthma, with particular emphasis on its impact on type 2 innate lymphoid cells (ILC2) and CD4+T cells, and then further elucidated whether EDA could inhibit house dust mite (HDM)-induced allergic asthma by affecting oxidative stress and ERS. Mice received intraperitoneally injection of EDA (10 mg/kg, 30 mg/kg), dexamethasone (DEX) and N-acetylcysteine (NAC), with the latter two used as positive control drugs. DEX and high dose of EDA showed better therapeutic effects in alleviating airway inflammation and mucus secretion in mice, along with decreasing eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) than NAC. Further, the protein levels of IL-33 in lung tissues were inhibited by EDA, leading to reduced activation of ILC2s in the lung. EDA treatment alleviated the activation of CD4+ T cells in lung tissues of HDM-induced asthmatic mice and reduced Th2 cytokine secretion in BALF. ERS-related markers (p-eIF2α, IRE1α, CHOP, GRP78) were decreased after treatment of EDA compared to HDM group. Malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) were detected to evaluate the oxidant stress in lung tissues. EDA showed a protective effect against oxidant stress. In conclusion, our findings demonstrated that EDA could suppress allergic airway inflammation by inhibiting oxidative stress and ERS, suggesting to serve as an adjunct medication for asthma in the future.

FGF10 attenuates allergic airway inflammation in asthma by inhibiting PI3K/AKT/NF-κB pathway.

BACKGROUND: The effect of fibroblast growth factor 10 (Fgf10) against allergic asthma has remained unclear, despite its importance in lung development and homeostasis maintenance. The purpose of this study was to investigate the protective effect and potential mechanism of Fgf10 on asthma. METHOD: House Dust Mite (HDM)-induced asthma mice were administered recombinant Fgf10 intranasally during activation. Flow cytometry and ELISA were performed to determine type of inflammatory cells and type 2 cytokines levels in bronchoalveolar lavage fluid (BALF). Hematoxylin and eosin (H&E) and periodic acid - Schiff (PAS) staining of lung sections were conducted to evaluate histopathological assessment. Transcriptome profiling was analyzed using RNA-seq, followed by bioinformatics and network analyses to investigate the potential mechanisms of Fgf10 in asthma. RT-qPCR was also used to search for and validate differentially expressed genes in human Peripheral Blood Mononuclear Cells (PBMCs). RESULTS: Exogenous administration of Fgf10 alleviated HDM-induced inflammation and mucus secretion in lung tissues of mice. Fgf10 also significantly inhibited the accumulation of eosinophils and type 2 cytokines (IL-4, IL-5, and IL-13) in BALF. The PI3K/AKT/NF-κB pathway may mediate the suppressive impact of Fgf10 on the asthma inflammation. Through RNA-seq analysis, the intersection of 71 differentially expressed genes (DEGs) was found between HDM challenge and Fgf10 treatment. GO and KEGG enrichment analyses indicated a strong correlation between the DEGs and different immune response. Immune infiltration analysis predicted the differential infiltration of five types of immune cells, such as NK cells, dendritic cells, monocytes and M1 macrophages. PPI analysis determined hub genes such as Irf7, Rsad2, Isg15 and Rtp4. Interestingly, above genes were consistently altered in human PBMCs in asthmatic patients. CONCLUSION: Asthma airway inflammation could be attenuated by Fgf10 in this study, suggesting that it could be a potential therapeutic target.

Atomization efficacy of a novel micro-dose mesh nebulizer (CVS-100) versus the traditional mesh nebulizer (M102) in adults with chronic obstructive pulmonary disease: A randomized non-inferiority clinical trial.

OBJECTIVE: To compare the atomization efficacy of a novel micro-dose mesh nebulizer (CVS-100) versus the traditional mesh nebulizer (M102) in nebulizing a combination of ipratropium bromide and salbutamol for treatment of stable moderate-to-severe chronic obstructive pulmonary disease (COPD). METHODS: A randomized, parallel, non-inferiority study was conducted. A total of 64 stable COPD patients were randomly assigned to either the experimental group or the control group in a 1:1 ratio. Each the experimental group received nebulized Combivent (Compound Ipratropium Bromide Solution) with CVS-100, while the control group received Combivent with M102. Lung ventilation function was measured before and 30 min after nebulization, and the difference in percentage of forced expiratory volume in the first second (FEV1) of predicted value (FEV1%pred), the forced expiratory flow at 50% (FEF50%), the forced expiratory flow at 75% (FEF75%), the mid-expiratory flow (FEF25-75%), and maximal voluntary ventilation (MVV) was evaluated. The non-inferiority margin for the lower 95% confidence limit was set at 3.5%. RESULTS: The lower limit of the 95% confidence interval for the difference in FEV1%pred between the two groups was -1.83357, which was greater than -3.5. No significant differences were found in FEF50%, FEF75%, FEF25∼75%, MVV before and after nebulization between the two groups. CONCLUSION: The novel micro-dose mesh nebulizer (CVS-100) was found to be non-inferior to the traditional mesh nebulizer (M102) in terms of the change in FEV1%pred from baseline after nebulization. Similar results were observed for all other measures of efficacy.

Identification and validation of ferroptosis-related genes in lipopolysaccharide-induced acute lung injury.

BACKGROUND: Emerging evidence reveals the important role of ferroptosis in the pathophysiological process of acute lung injury (ALI). We aimed to identify and validate the potential ferroptosis-related genes of ALI through bioinformatics analysis and experimental validation. METHODS: Murine ALI model was established via intratracheal instillation with LPS and confirmed by H&E staining and transmission electronic microscopy (TEM). RNA sequencing (RNA-seq) was used to screen differentially expressed genes (DEGs) between control and ALI model mice. The potential differentially expressed ferroptosis-related genes of ALI were identified using the limma R package. Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, gene set enrichment analysis (GSEA), and protein-protein interactions (PPI) were applied for the differentially expressed ferroptosis-related genes. CIBERSORT tool was used to conduct immune cell infiltration analysis. Finally, protein expressions and RNA expression of ferroptosis DEGs were validated in vivo and in vitro by western blots and RT-qPCR. RESULTS: Among 5009 DEGs, a total of 86 differentially expressed ferroptosis-related genes (45 up-regulated genes and 41 down-regulated genes) were identified in the lungs between control and ALI. GSEA analysis showed that the genes enriched were mainly involved in response to molecule of bacterial origin and fatty acid metabolic process. The GO and KEGG enrichment analysis indicated that the top 40 ferroptosis DEGs were mainly enriched in reactive oxygen species metabolic process, HIF-1signaling pathway, lipid and atherosclerosis, and ferroptosis. The PPI results and Spearman correlation analysis suggested that these ferroptosis-related genes interacted with each other. Immune infiltration analysis confirmed that ferroptosis DEGs were closely related to immune response. Consistent with the RNA-seq data, the western blot and RT-qPCR unveiled increased mRNA expressions of Cxcl2, Il-6, Il-1ß, and Tnfα, and protein expressions of FTH1, TLR4 as well as decreased ACSL3 in LPS-induced ALI. In vitro, the upregulated mRNA levels of CXCL2, IL-6, SLC2A1, FTH1, TNFAIP3, and downregulated NQO1 and CAV1 in LPS-stimulated BEAS-2B and A549 cells were verified. CONCLUSION: We identified 86 potential ferroptosis-related genes of LPS-induced ALI through RNA-seq. Several pivotal ferroptosis-related genes involved in lipid metabolism and iron metabolism were implicated in ALI. This study may be helpful to expand our understanding of ALI and provide some potential targets to counteract ferroptosis in ALI.

Development and Validation of a Nomogram for Predicting 28-Day Mortality on Admission in Elderly Patients with Severe Community-Acquired Pneumonia.

Introduction: There were few studies on the mortality of severe community-acquired pneumonia (SCAP) in elderly people. Early prediction of 28-day mortality of hospitalized patients will help in the clinical management of elderly patients (age ≥65 years) with SCAP, but a prediction model that is reliable and valid is still lacking. Methods: The 292 elderly patients with SCAP met the criteria defined by the American Thoracic Society from 33 hospitals in China. Clinical parameters were analyzed by the use of univariable and multivariable logistic regression analysis. A nomogram to predict the 28-day mortality in elderly patients with SCAP was constructed and evaluated using the area under the receiver operating characteristic curve (AUC) and internally verified using the Bootstrap method. Results: A total of 292 elderly patients (227 surviving and 65 died within 28 days) were included in the analysis. Age, Glasgow score, blood platelet, and blood urea nitrogen values were found to be significantly associated with 28-day mortality in elderly patients with SCAP. The AUC of the nomogram was 0.713 and the calibration curve for 28-day mortality also showed high coherence between the predicted and actual probability of mortality. Conclusion: This study provides a nomogram containing age, Glasgow score, blood platelet, and blood urea nitrogen values that can be conveniently used to predict 28-day mortality in elderly patients with SCAP. This model has the potential to assist clinicians in evaluating prognosis of patients with SCAP.

Weaker Response to XueBiJing Treatment in Severe Community-Acquired Pneumonia Patients With Higher Body Mass Index or Hyperglycemia: A Post Hoc Analysis of a Randomized Controlled Trial.

Background: Overweight and hyperglycemia might result in poor prognosis in patients with severe community-acquired pneumonia (SCAP). XueBiJing treatment could significantly improve the outcomes of patients with SCAP. We investigated the efficacy of XueBiJing injection in patients with SCAP stratified by body mass index (BMI) and fasting blood glucose (FBG). Methods: This is a post hoc analysis of XueBiJing trial, a large prospective, randomized, controlled study conducted in 33 hospitals in China. We compared data from non-overweight (BMI <24 kg/m2, n = 425) vs. overweight (BMI ≥24 kg/m2, n = 250) patients as well as non-hyperglycemia (FBG <7 mmol/L, n = 315) vs. hyperglycemia (FBG ≥7 mmol/L, n = 360) patients with XueBiJing, 100 ml, q12 h, or a visually indistinguishable placebo treatment for 5-7 days. Results: Among patients with BMI <24 kg/m2 (n = 425), 33 (15.3%), XueBiJing recipients and 52 (24.9%) placebo recipients (p = 0.0186) died within 28 days. Among patients with BMI ≥24 kg/m2 (n = 250), XueBiJing recipients still had lower mortality (XueBiJing 16.9% vs. placebo 24.2%; p = 0.2068) but without significantly statistical difference. For the FBG group, patients with FBG <7 mmol/L (n = 315), 18 (11.2%) XueBiJing recipients and 32 (20.8%) placebo recipients (p = 0.030) died within 28 days. Among patients with FBG ≥7 mmol/L (n = 360), XueBiJing recipients still had lower mortality (XueBiJing 20.2% vs. placebo 27.8%; p = 0.120) but without significantly statistical difference. The total duration of the ICU stay and the duration of mechanical ventilation were similar in both groups (p > 0.05). Conclusion: Overweight or hyperglycemia might weaken the efficacy of XueBiJing injection in the treatment of SCAP as indicated by the significant elevated risk of 28-day mortality. Additional studies are needed to validate our findings and to further understand the underlying mechanisms.

Low Eosinophil Phenotype Predicts Noninvasive Mechanical Ventilation Use in Patients with Hospitalized Exacerbations of COPD.

RATIONALE: Eosinophilic inflammation is related to the progression and outcomes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Till now, few studies have focused on low EOS in AECOPD. OBJECTIVE: To reveal the clinical characteristics, therapeutic responses and prognosis of patients hospitalized of AECOPD with low EOS. METHODS: The electronic database of Zhongshan Hospital, Fudan University was used. Cohort 1 included 608 patients with hospitalized AECOPD. Study population 2 consisted of 166 patients with AECOPD admission at least twice. Impact of low EOS on NIMV treatment, length of hospital stays and 12-month AECOPD-related readmission were analyzed with multivariable logistic regression model. Thirty-five hospitalized AECOPD patients were prospectively recruited as cohort 3 to explore the association between EOS and other immune cells using Spearman correlation coefficient for ranked data. RESULTS: EOS level was suppressed on admission in AECOPD patients, and significantly improved after hospitalized treatment (P < 0.05). For inflammatory markers, leucocytes, neutrophils and lactate dehydrogenase levels were higher, while lymphocytes, monocytes and interleukin-6 levels were lower in the low-EOS group than those in the non-low EOS group (P < 0.05). Low EOS (EOS < 50 cells/µL) was an independent risk factor of NIMV use (OR = 1.86, 95% CI = 1.26 ~ 2.73). The EOS percentage was positively correlated with the T cell percentage (r = 0.46, P < 0.05) and negatively correlated with the natural killer cell percentage (r = -0.39, P < 0.05). The patients with low EOS had lower level of CD4+ T cell (P < 0.05) than that of patients with non-low EOS. CONCLUSION: Low EOS might be a stable phenotype in patients with hospitalized AECOPD and could be used to inform NIMV management, hyperinflammatory state and impaired immunity situation.

Concomitant preoperative airflow obstruction confers worse prognosis after trans-thoracic surgery for esophageal cancer.

Background: Airflow obstruction is a critical element of chronic airway diseases. This study aimed to evaluate the impact of preoperative airflow obstruction on the prognosis of patients following surgery for esophageal carcinoma. Methods: A total of 821 esophageal cancer patients were included and classified into two groups based on whether or not they had preoperative airflow obstruction. Airflow obstruction was defined as a forced expiration volume in the first second (FEV1)/forced vital capacity (FVC) ratio below the lower limit of normal (LLN). A retrospective analysis of the impact of airflow obstruction on the survival of patients with esophageal carcinoma undergoing esophagectomy was performed. Results: Patients with airflow obstruction (102/821, 12.4%) had lower three-year overall (42/102, 58.8%) and progression-free survival rate (47/102, 53.9%) than those without airflow obstruction (P < 0.001). Multivariate analyses showed that airflow obstruction was an independent risk factor for overall survival (Hazard Ratio = 1.66; 95% CI: 1.17-2.35, P = 0.004) and disease progression (Hazard Ratio = 1.51; 95% CI: 1.1-2.08; P = 0.01). A subgroup analysis revealed that the above results were more significant in male patients, BMI < 23 kg/m2 patients or late-stage cancer (stage III-IVA) (P = 0.001) patients and those undergoing open esophagectomy (P < 0.001). Conclusion: Preoperative airflow obstruction defined by FEV1/FVC ratio below LLN was an independent risk factor for mortality in esophageal cancer patients after trans-thoracic esophagectomy. Comprehensive management of airflow obstruction and more personalized surgical decision-making are necessary to improve survival outcomes in esophageal cancer patients.