Locally organised and activated Fth1(hi) neutrophils aggravate inflammation of acute lung injury in an IL-10-dependent manner

Mechanisms of pulmonary fibrosis and lung cancer induced by chronic PM2.5 exposure: Focus on the airway epithelial barrier and epithelial-mesenchymal transition

This study aims to provide new insights into PM2.5-induced lung diseases through a focus on the pulmonary epithelial barrier and epithelial-mesenchymal transition (EMT). Firstly, we analyzed the mechanisms by which PM2.5 damages the airway epithelial barrier, including inflammatory responses, immune imbalance, oxidative stress, apoptosis, and autophagy. Subsequently, we investigated the mechanisms by which PM2.5 induces EMT, which involve the synergistic effect of oxidative stress and inflammation, the activation of key signaling pathways, and the regulatory role of non-coding RNAs. Furthermore, we explored the interaction between the airway epithelial barrier and EMT, especially the induction of EMT by epithelial barrier damage and the impact of EMT on epithelial barrier repair. Regarding lung injury diseases, we focused on the roles of the epithelial barrier and EMT in the development of pulmonary fibrosis and lung cancer, providing evidence from in vitro and in vivo studies. Emphasizing the translational prospects from basic research to clinical applications, and we proposed new ideas for treating PM2.5-related lung diseases from four aspects-anti-inflammatory and antioxidant drugs, signaling pathway inhibitors, non-coding RNA-targeted therapies, and gene editing and cell therapies-by focusing on the two key links of the airway epithelial barrier and EMT.

Targeting neutrophil dysfunction in acute lung injury: Insights from active components of Chinese medicine

BACKGROUNDS

Acute lung injury (ALI) is a lethal condition characterized by uncontrolled pulmonary inflammatory responses, with high morbidity and mortality rates that pose a significant threat to patient health. The persistent retention of neutrophils in lung tissue and subsequent inflammatory damage represents a primary mechanism underlying the early onset of ALI disorders. In recent years, pharmaceutical research targeting these pathological processes has garnered considerable attention. Traditional Chinese medicines (TCM) and their active ingredients, known for their safety and stability, show promising potential in treating ALI through their ability to modulate neutrophil function via multiple pathways.

PURPOSE

This review examines the mechanisms of neutrophil involvement in the pathogenesis of ALI, investigates potential therapeutic targets and pathways through which Chinese medicines and their active ingredients regulate neutrophil function, and provides a theoretical foundation for developing novel clinical treatment strategies.

METHODS

A comprehensive literature search was conducted using multiple databases, including Science Direct, PubMed, Google Scholar, and Web of Science. Search terms included 'lung injury,' 'acute lung injury,' 'inflammatory lung injury,' 'inflammation,' 'active ingredient,' 'herbal,' 'traditional Chinese medicine,' 'mechanism,' 'drug,' and 'neutrophils.' The selected literature was systematically categorized and analyzed.

RESULTS

Our review reveals that TCM and active ingredients influence neutrophil function through four primary mechanisms to impede ALI progression: 1) reduction of neutrophil-mediated uncontrolled inflammatory responses by suppressing neutrophil hyperactivation and inhibiting neutrophil migration and infiltration; 2) attenuation of lung tissue inflammatory damage by inhibiting neutrophil-produced cytotoxic substances, including elastase granules, neutrophil extracellular traps (NETs), and reactive oxygen species (ROS); 3) suppression of inflammatory responses by decreasing the secretion of neutrophil-derived cytokines, such as interleukin (IL) -1β, IL-6 and tumor necrosis factor-alpha (TNF-α); and 4) enhancement of neutrophil phagocytosis and accelerate the removal of apoptotic neutrophils to eliminate harmful pathogens and promote late-stage tissue repair. These findings demonstrate that Chinese medicines and their active ingredients exhibit significant therapeutic potential in ALI disorders through the modulation of neutrophil function, providing a robust theoretical framework for their clinical applications.

CONCLUSION

Traditional Chinese medicines and their active ingredients demonstrate significant anti-inflammatory efficacy through multiple mechanisms of neutrophil function regulation, showing considerable promise for the treatment of ALI with broad clinical applications.

Targeting mitochondrial complex I of CD177+ neutrophils alleviates lung ischemia-reperfusion injury

Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality following lung transplantation, with neutrophils playing a central role in its inflammatory pathology. Here, we employ single-cell RNA sequencing and spatial transcriptomics to investigate neutrophil subtypes in the lung ischemia-reperfusion injury (IRI) model. We identify CD177+ neutrophils as an activated subpopulation that significantly contributes to lung injury and serves as an early biomarker for predicting severe PGD in human lung transplant recipients (area under the curve [AUC] = 0.871). CD177+ neutrophils exhibit elevated oxidative phosphorylation and increased mitochondrial complex I activity, driving inflammation and the formation of neutrophil extracellular traps. Targeting mitochondrial function with the complex I inhibitor IACS-010759 reduces CD177+ neutrophil activation and alleviates lung injury in both mouse IRI and rat left lung transplant models. These findings provide a comprehensive landscape of CD177+ neutrophil-driven inflammation in lung IRI and highlight its potential value for future early diagnosis and therapeutic interventions.

Gastrodia elata Blume extract alleviates sepsis-induced lung injury by suppressing IL-23/IL-17 A axis

The Compendium of Materia Medica recorded that the traditional Chinese medicine Gastrodia elata Blume (G. elata) has applications in antibacterial and antiviral. GE05 was prepared from the rhizome of G. elata and its active ingredients have been proven to alleviate inflammatory response. However, the protective effect and the underlying mechanism of G. elata in sepsis remain unclear. Our study aims to uncover the efficacy and molecular mechanisms of GE05 in ameliorating sepsis-induced lung injury. Here, we have shown that GE05 could inhibit the expression of inflammatory cytokines in peritoneal macrophages. Bioinformatics analysis showed the activation of interleukin (IL)-17 signaling pathway in acute lung injury (ALI) mice. We established septicemia models and showed that GE05 improves survival rates and protects against sepsis-induced lung injury by downregulating the IL-23/IL-17 A axis. Quantitative real- time PCR (qPCR) analysis and immunohistochemistry have indicated that IL-17 A inhibition reduces the release of chemokine ligand (Cxcl) 1, Cxcl2, ‌granulocyte-macrophage colony stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF), mitigating neutrophil infiltration-induced lung tissue damage. Meanwhile, GE05 could inhibit the activation of the IL-17 A-related phosphatidylinositol 3-kinase/ c-Jun N-terminal kinase (PI3K/JNK) signaling pathway, suppressing the expression of tumor necrosis factor-alpha (TNF-α), IL-1β, and IL-6. These results demonstrated that GE05 is a promising agent that targets the IL-23/IL-17 A axis, providing new way for preventing and treating sepsis-induced lung injury.

NANS suppresses NF-κB signaling to promote ferroptosis by perturbing iron homeostasis

Metastatic colorectal cancer (CRC) cells endure survival challenges, including treatment-induced ferroptosis. While adaptation to ferroptosis stress facilitates metastasis, reciprocal regulatory mechanisms remain unclear. Here, a CRISPR-Cas9 screen identifies N-acetylneuraminate synthase (NANS) as a ferroptosis promoter in CRC, regardless of its metabolic function. NANS expression is downregulated and correlates with poor prognosis in patients with CRC. Under ferroptotic stress, cyclin-dependent kinase 1 (CDK1) phosphorylates NANS at serine 275 (S275), triggering its dissociation from TAK1. Phosphorylated NANS is ubiquitinated by UBE2N at K246, leading to degradation, which activates TAK1-NF-κB signaling and upregulates the ferroptosis inhibitor FTH1, enabling metastasis via ferroptosis resistance. NANS pS275 levels are associated with tumor aggressiveness and clinical outcomes in patients with CRC. These findings indicate that NANS suppresses CRC metastasis by enhancing ferroptosis susceptibility, while CDK1-mediated phosphorylation at S275 drives adaptive resistance. Targeting this phosphorylation axis may improve ferroptosis-inducing therapies to restrict metastatic progression in CRC.

MiR-629-5p May serve as a biomarker for pediatric acute respiratory distress syndrome and can regulate the inflammatory response

OBJECTIVE

Circulating microRNAs (miRNAs) are associated with pediatric acute respiratory distress syndromes (PARDS). This study analyzed the clinical significance and potential mechanism of microRNA (miR)-629-5p in PARDS.

METHODS

82 children with PARDS and 82 controls were enrolled. Serum levels of miR-629-5p were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and its diagnostic significance with respect to for PARDS in children was assessed by the receiver operating characteristic (ROC). Kaplan-Meier curve and multivariate Cox regression were utilized to examine the prognostic significance of miR-629-5p. An in vitro cell model was established using lipopolysaccharide (LPS)-induced alveolar epithelial cells A549. The cell proliferation, apoptosis, and inflammatory factors were assessed using cell counting kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA). miR-629-5p target genes were identified in the database and validated using the dual-luciferase report assay.

RESULTS

Serum miR-629-5p levels were significantly higher in children with PARDS than in controls (P < 0.05). miR-629-5p exhibited 86.6% sensitivity and 91.5% specificity in distinguishing children with PARDS. miR-629-5p was an independent risk factor for mortality, and high levels of miR-629-5p have a poor prognosis. LPS promoted apoptosis and overproduction of inflammatory factors in A549 and upregulated miR-629-5p expression (P < 0.05); however, they were partially reversed by the weakened miR-629-5p (P < 0.05). Syndecan-4 (SDC4) is a target of miR-629-5p. The inhibition of SDC4 induced by LPS can be alleviated through the reduction of miR-629-5p.

CONCLUSION

miR-629-5p serves as a diagnostic biomarker for children with PARDS and it is associated with poor prognosis. Diminished miR-629-5p may alleviate PARDS by targeting SDC4 to suppress apoptosis and inflammation of alveolar epithelial cells.

Spatiotemporal Transcriptomic Profiling Reveals the Dynamic Immunological Landscape of Alveolar Echinococcosis

Alveolar echinococcosis (AE) is caused by the chronic infection of E. multilocularis, whose tumor-like growth can lead to high fatality if improperly treated. The early diagnosis of infection and the treatment of advanced AE remain challenging. Herein, bulk RNA-seq, scRNA-seq, and spatial transcriptomics technologies are integrated, to reveal the host immune response mechanism against E. multilocularis both spatially and chronologically, collecting mouse liver samples at multiple timepoints up to 15 months post infection. These results unveil an unprecedented high-resolution spatial atlas of the E. multilocularis infection foci and the functional roles of neutrophils, Spp1+ macrophages, and fibroblasts during disease progression. The heterogeneity of neutrophil and macrophage subpopulations are critical in both parasite-killing and the occurrence of immunosuppression during AE progression. These findings indicate the transition of parasite control strategy from "active killing" to "negative segregation" by the host, providing instructive insights into the treatment strategy for echinococcosis.

Jatrorrhizine alleviates cytokine storm secondary lung injury via regulating CD39-dominant purinergic braking and downstream NLRP3 inflammasome

Cytokine storm secondary lung injury (CSSLI) is a form of acute lung injury (ALI) comparable to that caused by sepsis for which there are no effective therapeutic strategies. Coptis chinensis Franch. and Scutellaria baicalensis Georgi. are two botanical medicines that exhibit anti-inflammatory properties. This study aimed to investigate the underlying therapeutic mechanism of the combination (CCSB) treatment in mice with ALI. A high dosage of lipopolysaccharide (LPS) was administered intraperitoneally to C57BL/6 mice to establish an ALI model. The AMP-Glo™ assay was applied to screen for the component with the most potent CD39-promoting enzyme activity from CCSB constituents migrating to the bloodstream. The PMA-differentiated THP-1 and RAW264.7 macrophage cell lines were stimulated with LPS and adenosine triphosphate, followed by treatment with Jatrorrhizine (JH). The administration of CCSB demonstrated a notable improvement in lung injury through the modulation of the CD39-P2X7 purinergic pathway and subsequent regulation of the NLRP3 inflammasome. The restrained CD39 and A2b were reversed by JH, leading to the suppression of the P2X7-NLRP3 signaling pathway. In addition, the utilization of a CD39 inhibitor (POM-1) attenuated the inhibitory effect of JH on the NLRP3 signaling pathway. CCSB successfully rescued CSSLI, along with its small-molecule component JH, which demonstrated the ability to inhibit the NLRP3 signaling pathway and pyroptosis, at least partially through regulating the CD39 enzyme.

A machine learning model for predicting acute respiratory distress syndrome risk in patients with sepsis using circulating immune cell parameters: a retrospective study

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe complication associated with a high mortality rate in patients with sepsis. Early identification of patients with sepsis at high risk of developing ARDS is crucial for timely intervention, optimization of treatment strategies, and improvement of clinical outcomes. However, traditional risk prediction methods are often insufficient. This study aimed to develop a machine learning (ML) model to predict the risk of ARDS in patients with sepsis using circulating immune cell parameters and other physiological data.

METHODS

Clinical data from 10,559 patients with sepsis were obtained from the MIMIC-IV database. Principal component analysis (PCA) was used for dimensionality reduction and to comprehensively evaluate the models' predictive capabilities, we used several ML algorithms, including decision trees, k-nearest neighbors (KNN), logistic regression, naive Bayes, random forests, neural networks, XGBoost, and support vector machines (SVM) to predict ARDS risk. The model performance was assessed using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, and F1 score. Shapley additive explanations (SHAP) were used to interpret the contribution of individual features to model predictions.

RESULTS

Among all models, XGBoost showed the best performance with an AUC of 0.764. Feature importance analysis revealed that mean arterial pressure, monocyte count, neutrophil count, pH, and platelet count were key predictors of ARDS risk in patients with sepsis. The SHAP analysis provided further information on how these features contributed to the model's predictions, aiding in interpretability and potential clinical applications.

CONCLUSION

The XGBoost model using circulating immune cell parameters accurately predicted the risk of ARDS in patients with sepsis. This model could be a useful tool for the early identification of high-risk patients and timely intervention; however, further validation and integration into clinical practice are required.

OTUD1 Deficiency Alleviates LPS-Induced Acute Lung Injury in Mice by Reducing Inflammatory Response

The ovarian tumor (OTU) family consists of deubiquitinating enzymes thought to play a crucial role in immunity. Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) pose substantial clinical challenges due to severe respiratory complications and high mortality resulting from uncontrolled inflammation. Despite this, no study has explored the potential link between the OTU family and ALI/ARDS. Using publicly available high-throughput data, 14 OTUs were screened in a simulating bacteria- or LPS-induced ALI model. Subsequently, gene knockout mice and transcriptome sequencing were employed to explore the roles and mechanisms of the selected OTUs in ALI. Our screen identified OTUD1 in the OTU family as a deubiquitinase highly related to ALI. In the LPS-induced ALI model, deficiency of OTUD1 significantly ameliorated pulmonary edema, reduced permeability damage, and decreased lung immunocyte infiltration. Furthermore, RNA-seq analysis revealed that OTUD1 deficiency inhibited key pathways, including the IFN-γ/STAT1 and TNF-α/NF-κB axes, ultimately mitigating the severity of immune responses in ALI. In summary, our study highlights OTUD1 as a critical immunomodulatory factor in acute inflammation. These findings suggest that targeting OTUD1 could hold promise for the development of novel treatments against ALI/ARDS.

E3 Ubiquitin Ligase TRIM7 Alleviates Lipopolysaccharide-Induced Acute Lung Injury via Inhibiting NLRP3 Inflammasome Activation

Acute lung injury (ALI) is a common clinical disease with high mortality, characterized by tissue damage caused by excessive activation of inflammation. TRIM7 is an E3 ligase that plays an important role in regulating viral infection, tumor progression, and innate immune response. However, its function in ALI is unclear. In this study, lipopolysaccharide (LPS) was used to stimulate C57BL/6j mice and HULEC-5a cells to establish ALI models in vivo and in vitro. TRIM7 expression was down-regulated during ALI. Furthermore, overexpressing TRIM7 in HULEC-5a cells relieved cell damage and inflammatory activation induced by LPS stimulation. TRIM7 knockdown had the opposite effect. Trim7-overexpressing mice were established by endotracheal injection of adeno-associated virus 6-Trim7 virus in vivo; the ALI model was then induced by LPS stimulation. Overexpression of TRIM7 could alleviate lung tissue injury, pulmonary interstitial hemorrhage, increased alveolar and vascular permeability, inflammatory cell infiltration, and secretion of inflammatory factors induced by LPS stimulation. Mechanistically, TRIM7 inhibited the expression of NOD-, LRR- and pyrin domain-containing 3 (NLRP3) and the activation of the NLRP3 inflammasome. The regulatory effect of TRIM7 on ALI depended on the NLRP3 inflammasome. This investigation, for the first time, showed the inhibitory effect of TRIM7 on ALI and activation of the NLRP3 inflammasome, providing new targets and ideas for the research on the mechanism and treatment of ALI.

FABP4 expression in neutrophils as a predictor of sepsis and SI-ARDS based on BALF transcriptome and peripheral blood validation

BACKGROUND

The objective of this study is to delineate the differential gene expression patterns of neutrophils in bronchoalveolar lavage fluid (BALF) from patients with sepsis and those experiencing progression to sepsis-induced acute respiratory distress syndrome (SI-ARDS). Additionally, we aim to comprehensively profile the transcriptomic landscape of neutrophils in BALF from patients with sepsis and SI-ARDS, particularly focusing on cases caused by specific bacterial pathogens.

METHODS

Patients with confirmed sepsis (n = 14) or SI-ARDS (n = 11) were recruited. Besides, a control group consisting of patients with unrelated diseases (n = 7) who required bronchoscopy was also included (cohort 1). We collected the neutrophils in BALF from participants in cohort 1. To validate the identified differentially expressed genes (DEGs) and evaluate neutrophil apoptosis, an additional cohort (cohort 2) was recruited, consisting of 5 healthy controls, 10 patients with sepsis, and 10 patients with SI-ARDS. Peripheral blood neutrophils were collected from participants in cohort 2 for further analysis. DEGs between SI-ARDS patients and controls, sepsis patients and controls, as well as SI-ARDS patients and sepsis patients were identified. And, publicly available datasets were downloaded to compare with local results. Additionally, the DEGs were also identified between patients infected with drug-resistant Klebsiella pneumoniae and those infected with other bacterial pathogens. Furthermore, a third cohort (cohort 3) consisting of 57 sepsis patients and 46 SI-ARDS patients was recruited for investigating the prognostic significance of neutrophils in SI-ARDS.

RESULTS

In cohort 1, 8/14 of the septic patients and 6/11 of the SI-ARDS patients were affected by drug-resistant Klebsiella pneumonia. There were 9921 DEGs between sepsis patients and controls, 10,252 DEGs between SI-ARDS patients and controls, and 24 DEGs between SI-ARDS and sepsis patients in neutrophils from BALF. Notably, fatty acid-binding pro-tein 4 (FABP4) exhibited significant downregulation in SI-ARDS patients. In cohort 2, peripheral blood analysis confirmed consistent trends, demonstrating that FABP4 expression was decreased, which contributed to the attenuation of neutrophil apoptosis. And FABP4 inhibitor-induced apoptosis resistance was reversed by a phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) inhibitor. Furthermore, survival analysis revealed that SI-ARDS patients with low levels of neutrophil FABP4 expression exhibited poor survival. Additionally, 520 overlapping DEGs were identified between the sepsis and control group comparisons and the SI-ARDS and sepsis group comparisons. Among these overlapping DEGs, 85% were downregulated, predominantly targeting immune-related pathways, whereas a smaller subset was upregulated, mainly associated with metabolism. DEGs in neutrophils in BALF of SI-ARDS and controls notably overlapped with those in neutrophils in peripheral blood. Importantly, DEGs in sepsis/SI-ARDS caused by drug-resistant Klebsiella pneumoniae differed from DEGs in sepsis/SI-ARDS caused by other bacteria. Additionally, FABP4 expression consistently decreased, attenuating neutrophil apoptosis.

CONCLUSIONS

The downregulation of FABP4 in neutrophils was found to inhibit apoptosis through the activation of the PI3K/AKT signaling pathway. Importantly, the expression level of FABP4 in neutrophil emerged as a prognostic indicator for sepsis and SI-ARDS patients, suggesting its potential utility in clinical decision-making to address the challenges posed by this condition.

Neutrophil-derived heparin-binding protein increases endothelial permeability in acute lung injury by promoting TRIM21 and the ubiquitination of P65

Acute lung injury (ALI), which poses a significant public health threat, is commonly caused by sepsis. ALI is associated with permeability and glycolysis changes in pulmonary microvascular endothelial cells. Our study demonstrates that heparin-binding protein (HBP), released from neutrophils during sepsis, exacerbates endothelial permeability and glycolysis, thereby triggering ALI. Through coimmunoprecipitation and mass spectrometry, TRIM21 was identified as a HBP interaction partner. Notably, HBP enhances the protein stability of TRIM21 by inhibiting K48 ubiquitination. TRIM21 binds to and promotes K63-linked ubiquitination of P65, facilitating its nuclear translocation. TRIM21 regulates HPMEC permeability and glycolysis in a manner dependent on P65 nuclear translocation. HBP stabilizes TRIM21 and enhances TRIM21 interactions with P65. Rescue experiments conducted in vivo and in vitro demonstrate that modulation of endothelial permeability and glycolysis by HBP is predominantly mediated through the TRIM21-P65 axis. Our results suggest that targeting the HBP/TRIM21/P65 axis is a novel therapeutic strategy to ameliorate ALI.

Laminarin Alleviates Acute Lung Injury Induced by LPS Through Inhibition of M1 Macrophage Polarisation

The lipopolysaccharide-induced acute lung injury (ALI) mouse model is used to simulate human acute respiratory distress syndrome (ARDS), which has a high mortality rate. An imbalance between M1 and M2 macrophages, characterised by an increase in M1 macrophages, was observed in sepsis-induced ALI. We report that laminarin, an active ingredient found in algae, exhibits exceptional performance in a mouse model of sepsis-induced ALI. It ameliorates lung edema, enhances the survival rate of mice and reduces the levels of the inflammatory factors TNF-α and IL-6. Furthermore, laminarin reduced the expression of CD86, which are markers associated with M1 macrophages. Laminarin treatment reduces the secretion of TNF-α and IL-6 in LPS-stimulated macrophages. Laminarin treatment also decreases glucose uptake in LPS-stimulated macrophages. Transcriptome sequencing reveals that genes downregulated in LPS-stimulated macrophages following laminarin treatment are predominantly enriched in the HIF-1α signalling pathway. Experimental validation confirms that laminarin treatment of LPS-stimulated macrophages reduces the expression of HIF-1α and significantly decreases the expression of related indicators ROS and NLRP3. After using siRNA to knock down HIF-1α in RAW264.7 cells, the inhibitory effect of laminarin on LPS-induced M1 polarisation of macrophages is abolished. This suggests that laminarin may potentially inhibit macrophage polarisation towards the M1 phenotype by downregulating the HIF-1α signal. In conclusion, the data presented in our study demonstrate that laminarin can effectively reduce M1 macrophage polarisation by downregulating HIF-1α signalling. This makes it a novel candidate drug for the treatment of LPS-induced ALI.

Biomimetic fucoidan nanoparticles with regulation of macrophage polarization for targeted therapy of acute lung injury

Acute lung injury (ALI) is a complex acute respiratory illness with a high mortality rate. Reactive oxygen species (ROS) play a pivotal role in ALI, inducing cellular damage, inflammation, and oxidative stress, thereby exacerbating the severity of the injury. In this study, inspired by the "subtractive" strategy, we developed a fucoidan-based macrophage membrane bio-nanosystem, abbreviated as MF@CB, designed as an anti-inflammatory and antioxidant agent to alleviate lipopolysaccharide (LPS)-induced inflammation in ALI. MF@CB coated with macrophage membrane for effective targeting and accumulation in ALI lesions. In addition, MF@CB activates Nrf2 transcriptional activity in macrophages, inhibiting ROS synthesis at its origin while effectively removing ROS already present in the ALI. This dual-pronged approach demonstrates robust antioxidant properties and restores the macrophage antioxidant defense barrier. In the LPS-induced ALI mouse model, MF@CB significantly mitigated lung inflammatory damage by modulating lung macrophage polarization and inhibiting the over-secretion of pro-inflammatory cytokines by activated immune cells. More importantly, unlike most surface modification strategies because it remove the molecule, this approach is easier to apply and potentially safer and may provide useful insights into the development of more effective therapeutic strategies for ALI.

Advancements in omics technologies: Molecular mechanisms of acute lung injury and acute respiratory distress syndrome (Review)

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an inflammatory response arising from lung and systemic injury with diverse causes and associated with high rates of morbidity and mortality. To date, no fully effective pharmacological therapies have been established and the relevant underlying mechanisms warrant elucidation, which may be facilitated by multi‑omics technology. The present review summarizes the application of multi‑omics technology in identifying novel diagnostic markers and therapeutic strategies of ALI/ARDS as well as its pathogenesis.

Pathophysiological mechanisms of ARDS: a narrative review from molecular to organ-level perspectives

BACKGROUND

Acute respiratory distress syndrome (ARDS) remains a life-threatening pulmonary condition with persistently high mortality rates despite significant advancements in supportive care. Its complex pathophysiology involves an intricate interplay of molecular and cellular processes, including cytokine storms, oxidative stress, programmed cell death, and disruption of the alveolar-capillary barrier. These mechanisms drive localized lung injury and contribute to systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Unlike prior reviews that primarily focus on isolated mechanisms, this narrative review synthesizes the key pathophysiological processes of ARDS across molecular, cellular, tissue, and organ levels.

MAIN BODY

By integrating classical theories with recent research advancements, we provide a comprehensive analysis of how inflammatory mediators, metabolic reprogramming, oxidative stress, and immune dysregulation synergistically drive ARDS onset and progression. Furthermore, we critically evaluate current evidence-based therapeutic strategies, such as lung-protective ventilation and prone positioning, while exploring innovative therapies, including stem cell therapy, gene therapy, and immunotherapy. We emphasize the significance of ARDS subtypes and their inherent heterogeneity in guiding the development of personalized treatment strategies.

CONCLUSIONS

This narrative review provides fresh perspectives for future research, ultimately enhancing patient outcomes and optimizing management approaches in ARDS.

Aerosol inhalation of rhIL-10 improves acute lung injury in mice by affecting pulmonary neutrophil phenotypes through neutrophil-platelet aggregates

This study investigates the therapeutic effects of recombinant human IL-10 (rhIL-10) administered via aerosol inhalation in acute lung injury (ALI), with a particular focus on neutrophils. It explores how rhIL-10, in the presence of platelets, modulates neutrophil polarization to ameliorate acute lung injury. Initially, the ALI model established in mice demonstrated that aerosol inhalation of rhIL-10 significantly mitigated the cytokine storm in the lungs, reduced pulmonary edema, and alleviated histopathological damage to lung tissue. Additionally, rhIL-10 administration was found to decrease neutrophil infiltration and platelet activation in the lungs of mice, inhibiting the formation of platelet-neutrophil aggregates (PNAs) and promoting the differentiation of neutrophils toward an anti-inflammatory phenotype in the presence of platelets. Subsequently, primary neutrophils and platelets were isolated from mouse bone marrow and blood to explore the underlying mechanisms. The results indicated that rhIL-10 promotes the expression of the signal transducer and activator of transcription 3 (STAT3) and the suppressor of cytokine signaling 3 (SOCS3) in neutrophils while inhibiting the activation of the nuclear factor kappa B (NF-κB) and the NF-κB inhibitor (IκB), which in turn enhances CD40 expression. This interaction facilitates the formation of PNAs and influences neutrophil phenotype differentiation. Furthermore, the application of the STAT3 phosphorylation inhibitor Stattic and CD40 antibody in vivo provided further validation of this potential mechanism. In conclusion, these results indicate that aerosol inhalation of rhIL-10 effectively ameliorates ALI. The underlying mechanism may involve the modulation of the neutrophil STAT/SOCS-IκB/NF-κB-CD40 signaling pathway, promoting interactions between neutrophils and platelets that facilitate the differentiation of neutrophils toward an anti-inflammatory phenotype.

Fei-yan-qing-hua decoction exerts an anti-inflammatory role during influenza by inhibiting the infiltration of macrophages and neutrophils through NF-κB and p38 MAPK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Fei-Yan-Qing-Hua decoction (FYQHD) is an empirical formula that has shown clinical success in treating community-acquired pneumonia (CAP) for two decades. Influenza viral infection is a significant trigger for severe pneumonia, yet the role of FYQHD in treating influenza remains unclear.

AIM OF THE STUDY

This study aimed to assess the potential efficacy of FYQHD in treating influenza viral infection and to elucidate its underlying mechanisms.

MATERIALS AND METHODS

The protective effects of FYQHD against influenza were evaluated through survival assessments and pathological analyses. Transcriptomic analysis was performed to identify the genes and pathways influenced by FYQHD in influenza. The anti-inflammatory effects and molecular mechanisms of FYQHD were studied in macrophages stimulated by Toll-like receptor (TLR) 7 ligation in vitro. The key constituents of FYQHD absorbed in mouse sera were identified using untargeted metabolomics, and the anti-inflammatory activity of some of these compounds in macrophages was evaluated using ELISA.

RESULTS

Our findings demonstrate that FYQHD enhances survival and reduces lung damage in PR8-infected mice, primarily through its anti-inflammatory properties. Lung indexes and organ damage were significantly lower in the PR8 + OSV + FYQHD group compared to the PR8 + OSV group, indicating a potential complementary therapeutic effect of FYQHD and OSV in treating influenza. FYQHD effectively reduced chemokine expression, thereby decreasing the chemotaxis and infiltration of inflammatory monocytes/macrophages and neutrophils in the lungs. The anti-inflammatory effects of FYQHD in macrophages were achieved through the inhibition of NF-κB activation and p38 phosphorylation. The key constituents of FYQHD absorbed in mouse sera were identified, with some, such as wogonin, luteolin, kaempferol, and isorhamnetin, showing anti-inflammatory effects in primary macrophages.

CONCLUSION

FYQHD demonstrates protective efficacy against influenza and shows promise as an adjuvant therapeutic agent, particularly when used in combination with antiviral drugs like OSV. The potent anti-inflammatory components within FYQHD provide a basis for further exploration in drug research and development aimed at combating influenza.

Eldecalcitol alleviates diabetic periodontitis by regulating macrophage efferocytosis and polarization via SOCE machinery

Diabetes exacerbates the occurrence and severity of periodontitis, the pathogenesis of diabetic periodontitis (DPD) is influenced by the delayed resolution of inflammation. Eldecalcitol (ED-71) has shown promise in preventing bone loss in DPD. We herein aimed to investigate the role of ED-71 in the inflammatory regression phase of DPD and elucidate the underlying mechanisms. Type-2 diabetes was induced by streptozotocin injection in Wistar rats, and to explore the in vivo effect of ED-71 on macrophage efferocytosis, periodontitis was induced by ligation combined with lipopolysaccharide. Alveolar bone destruction was assessed using micro-computed tomography, hematoxylin-eosin, immunohistochemistry, and tartrate-resistant acid phosphatase staining. Immunofluorescence staining and flow cytometry detected neutrophils, apoptotic cells, and macrophage polarization in periodontal tissue. Additionally, flow cytometry, real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were used to examine macrophage efferocytosis and changes in store-operated calcium entry (SOCE). We found that rats with diabetes exhibited more severe alveolar bone destruction and increased neutrophil aggregates in periodontal tissue. Following the ED-71 administration, alveolar bone loss significantly decreased, and the immune microenvironment of periodontal tissue tended to suppress inflammation. Macrophages stimulated with high glucose experienced disruption of SOCE machinery, leading to the inhibition of efferocytosis in vitro. ED-71 demonstrated the ability to restore macrophage efferocytosis by correcting SOCE, and preventing sustained inflammatory damage to periodontal tissue. In conclusion, diabetes impairs macrophage efferocytosis and M2 polarization in periodontitis rats, resulting in the delayed resolution of inflammation. ED-71 could attenuate alveolar bone loss by mitigating macrophage via SOCE machinery in DPD.

Neutrophil extracellular traps (NETs) are increased in rheumatoid arthritis-associated interstitial lung disease

BACKGROUND

Neutrophil extracellular trap (NET) formation has been implicated as a pathogenic mechanism in both rheumatoid arthritis (RA) and interstitial lung disease (ILD). However, the role of NETs in RA-associated ILD (RA-ILD) and the mechanisms driving NET formation remain unclear. This study aimed to assess the involvement of NETs in RA-ILD and elucidate the underlying mechanisms.

METHODS

Single-cell sequencing was used to identify changes in the quantity and function of neutrophils in the lung tissue of a zymosan A (ZYM)-induced interstitial pneumonia arthritis model. Additionally, nuclear receptor 4A3 (NR4A3) interference was performed in HL-60 cells to assess its impact on NET formation and the transformation of MRC-5 cells into myofibroblasts. The clinical relevance of plasma myeloperoxidase-DNA (MPO-DNA), citrullinated histone 3 (Cit-H3), and cell-free DNA was evaluated in RA-ILD patients with different imaging types via a commercial enzyme-linked immunosorbent assay (ELISA).

RESULTS

In the ZYM-treated SKG mouse model, which recapitulates key features of RA-ILD, an increased population of neutrophils in the lung tissue was primarily responsible for NET formation. Mechanistically, we found that interference with NR4A3 expression enhanced NET formation in HL-60 cells, which in turn promoted the differentiation of MRC-5 cells into myofibroblasts. Clinically, plasma MPO-DNA levels are elevated in patients with RA-nonspecific interstitial pneumonia (RA-NSIP), whereas Cit-H3 levels are elevated in RA-usual interstitial pneumonia (RA-UIP) patients compared with healthy subjects. ROC curve analysis further revealed that the combination of plasma MPO-DNA, rheumatoid factor (RF), and anti-citrullinated protein (anti-CCP) and the combination of Cit-H3, RF, and anti-CCP were superior diagnostic panels for NSIP and UIP in RA-ILD patients, respectively. Moreover, compared with those from healthy controls, neutrophils from patients with RA-UIP and RA-NSIP demonstrated a significantly increased ability to form NETs and induce the differentiation of MRC-5 cells into myofibroblasts. Specifically, RA-UIP patients exhibited a greater capacity for NET formation and the differentiation of MRC-5 cells into myofibroblasts than did RA-NSIP patients.

CONCLUSIONS

These findings suggest that targeting NETs may be a novel therapeutic approach for treating ILD in RA patients.

A novel technique of cryodenervation for murine vagus nerve: implications for acute lung inflammation

BACKGROUND

Neuroimmune interaction is an underestimated mechanism for lung diseases, and cryoablation is a competitive advantageous technique than other non-pharmacologic interventions for peripheral nerve innervating the lung. However, a lack of cryodenervation model in laboratory rodents leads to the obscure mechanisms for techniques used in clinic.

METHOD

Herein, we developed a novel practical method for mouse peripheral nerve cryoablation, named visualized and simple cryodenervation (VSCD). We first estimated the feasibility, safety and effectiveness of the technique via haematoxylin-eosin staining, histochemistry or immunofluorescence staining and immunoblotting assay. We then constructed the acute lung injury (ALI) model triggered by lipopolysaccharide (LPS) to verify the effect of VSCD in the resolution of pulmonary inflammation. Besides, the IL-10 knockout mice were also applied to explain the underlying mechanism of the protective activity of VSCD in ALI mice.

RESULT

We demonstrated that VSCD was able to induce a reliable and stable blockade of innervation, but reversible structural damage of mouse vagus nerve without detectable toxicity to lung tissues. Cholinergic parasympathetic nerve in the mouse lung coming from vagus nerve was activated at the initial stage (1 week) after VSCD, and blocked 3 weeks later. By use of the ALI mouse model, we found that VSCD effectively decreased pulmonary inflammation and tissue damage in the ALI mice. Moreover, the activated cholinergic anti-inflammatory pathway (CAP) and elevated IL-10 expression might explain the protective action of VSCD following LPS challenge.

CONCLUSION

This study fills the gap in the cryoablation for mouse vagus nerve, thereby guiding the application of cryodenervation in clinical management of pulmonary diseases. It also offers evidence of anti-inflammatory potential of VSCD in ALI mouse model and opens therapeutic avenues for the intervention of acute lung inflammation.

Nanoscopy reveals integrin clustering reliant on kindlin-3 but not talin-1

BACKGROUND

Neutrophils are the most abundant leukocytes in human blood, and their recruitment is essential for innate immunity and inflammatory responses. The initial and critical step of neutrophil recruitment is their adhesion to vascular endothelium, which depends on G protein-coupled receptor (GPCR) triggered integrin inside-out signaling that induces β2 integrin activation and clustering on neutrophils. Kindlin-3 and talin-1 are essential regulators for the inside-out signaling induced β2 integrin activation. However, their contribution in the inside-out signaling induced β2 integrin clustering is unclear because conventional assays on integrin clustering are usually performed on adhered cells, where integrin-ligand binding concomitantly induces integrin outside-in signaling.

METHODS

We used flow cytometry and quantitative super-resolution stochastic optical reconstruction microscopy (STORM) to quantify β2 integrin activation and clustering, respectively, in kindlin-3 and talin-1 knockout leukocytes. We also tested whether wildtype or Pleckstrin homology (PH) domain deleted kindlin-3 can rescue the kindlin-3 knockout phenotypes.

RESULTS

GPCR-triggered inside-out signaling alone can induce β2 integrin clustering. As expected, both kindlin-3 and talin-1 knockout decreases integrin activation. Interestingly, only kindlin-3 but not talin-1 contributes to integrin clustering in the scenario of inside-out-signaling, wherein a critical role of the PH domain of kindlin-3 was highlighted.

CONCLUSIONS

Since talin was known to facilitate integrin clustering in outside-in-signaling-involved cells, our finding provides a paradigm shift by suggesting that the molecular mechanisms of integrin clustering upon inside-out signaling and outside-in signaling are different. Our data also contradict the conventional assumption that integrin activation and clustering are tightly inter-connected by showing separated regulation of the two during inside-out signaling. Our study provides a new mechanism that shows kindlin-3 regulates β2 integrin clustering and suggests that integrin clustering should be assessed independently, aside from integrin activation, when studying leukocyte adhesion in inflammatory diseases.

Alleviating Acute Lung Injury Induced by Lipopolysaccharide: Dayuan Yin Suppresses Inflammation and Oxidative Stress in Elderly Male Rats

BACKGROUND

The occurrence of acute lung injury (ALI) caused by lipopolysaccharide (LPS) is prevalent and perilous among older individuals. Inflammation and oxidative stress are vital factors in the progression of ALI in this population. Dayuan Yin (DYY) is a classic Chinese herbal formula used for treating pulmonary diseases. Therefore.this situation can be well simulated by selecting suitable aged rats and induced by LPS, which is helpful to evaluate the role of DYY.

OBJECTIVE

The objective of this study is to assess the therapeutic efficacy of DYY in reducing pulmonary inflammation and oxidative stress injury in aged rats induced by LPS.

METHODS

In elderly male Sprague Dawley (SD) rats, the ALI model was induced by injecting LPS into the peritoneal cavity. The therapeutic effect of the DYY group was evaluated after 3 days of oral administration. Lung tissue damage was assessed using hematoxylin-eosin staining and the lung wet/dry (W/D) ratio. Inflammatory reaction in lung tissue was analyzed by counting inflammatory agents, measuring total protein (TP), and examining the concentration of inflammatory components in bronchoalveolar lavage fluid (BALF). Lung oxidative stress was assessed by measuring malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), and superoxide dismutase (SOD) levels in BALF. The impact of DYY on the phosphorylation of PI3K, AKT, and NF-κBp65 protein was analyzed using Western Blot (WB).

RESULTS

The administration of DYY exhibited a dose-dependent reduction in the severity of lung injury caused by LPS, leading to a reversal of the LPS-induced lung W/D ratio. Furthermore, DYY treatment resulted in decreased levels of leukocytes, eosinophils, neutrophils, macrophages, lymphocytes, and total protein in BALF. Additionally, DYY significantly inhibited the upregulation of Interleukin -6, Interleukin -10, and Interleukin -1β (IL-6, IL-10, IL-1β) as well as Tumor necrosis factor-α(TNF-α) induced by LPS (P<0.01). The lungs experienced oxidative stress due to LPS, leading to the production of MDA and iNOS, as well as a decrease in SOD activity. DYY reduced oxidative stress in the lungs and inhibited the activation of p-PI3K, p-Akt, and p-NF-κBp65, with a greater effect at higher doses.

CONCLUSION

In a dose-dependent manner, DYY suppresses the inflammatory response and oxidative stress in the lung tissue of elderly rats, thereby reducing ALI caused by LPS. This effect may be attributed to the inhibition of the PI3K/AKT/NF-κB pathway activation.

Application of Macrophage Subtype Analysis in Acute Lung Injury/Acute Respiratory Distress Syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common critical illness. Supportive therapy is still the main strategy for ALI/ARDS. Macrophages are the predominant immune cells in the lungs and play a pivotal role in maintaining homeostasis, regulating metabolism, and facilitating tissue repair. During ALI/ARDS, these versatile cells undergo polarization into distinct subtypes with significant variations in transcriptional profiles, developmental trajectory, phenotype, and functionality. This review discusses developments in the analysis of alveolar macrophage subtypes in the study of ALI/ARDS, and the potential value of targeting new macrophage subtypes in the diagnosis, prognostic evaluation, and treatment of ALI/ARDS.

Exploring the Effect and Mechanism of DaYuan Yin Against Acute Lung Injury by Network Pharmacology, Molecular Docking, and Experimental Validation

Background

DaYuan Yin (DYY), a traditional Chinese medicine for lung diseases, requires further study to understand how it improves acute lung injury (ALI). This study seeks to elucidate the material basis and molecular mechanisms underlying the treatment of ALI with DYY through network pharmacology, molecular docking, and experimental validation.

Methods

DYY's active components and targets were identified using TCMSP and UHPLC-MS/MS, and a herb-component-target network was created with Cytoscape 3.7.2. ALI target genes were sourced from GeneCards, DisGeNET, and DrugBank. A PPI network was built, with core targets analyzed through GO and KEGG enrichment via Metscape. The therapeutic effects and mechanisms of DYY on LPS-induced ALI in rats were explored, and molecular docking evaluated the interactions between Nrf2, HO-1, TLR4, and the components.

Results

The study identified 95 active compounds, 234 therapeutic targets, and 2529 ALI-related genes, with 111 shared targets between DYY and ALI. KEGG analysis indicates that the PI3K-AKT, MAPK, and oxidative stress pathways are associated with DYY's anti-ALI effects. Network pharmacology and UHPLC-MS/MS analysis revealed active ingredients like quercetin, Magnolol, and Wogonin. Compared with the model group, DYY reduced the lung dry-wet ratio (W/D) of ALI rats from (5.31 ± 0.51) to (4.47 ± 0.73)(P < 0.05). Meanwhile, the contents of IL-6 and TNF-α in bronchoalveolar lavage fluid (BALF) and MDA, NO and ROS in lung tissue were also significantly decreased. Notably, DYY enhances UCP2 mRNA expression, boosts Nrf2 and HO-1 expression, and inhibits TLR4-mediated pro-inflammatory mediators. Molecular docking analysis showed that the main components of DYY had strong binding ability with HO-1.

Conclusion

DYY can alleviate inflammation, oxidative stress, and ALI-related changes by targeting the Nrf2/HO-1 mediated TLR4 pathway, providing insights for developing effective ALI treatments.

Deciphering the therapeutic potential of Myeloid-Specific JAK2 inhibition in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by severe inflammation and pulmonary dysfunction. Despite advancements in critical care, effective pharmacological interventions for ARDS remain elusive. While Janus kinase 2 (JAK2) inhibitors have emerged as an innovative treatment for numerous autoinflammatory diseases, their therapeutic potential in ARDS remains unexplored. In this study, we investigated the contribution of JAK2 and its underlying mechanisms in ARDS utilizing myeloid-specific JAK2 knockout murine models alongside a pharmacological JAK2 inhibitor. Notably, myeloid-specific JAK2 knockout led to a notable attenuation of ARDS induced by intratracheal administration of LPS, accompanied by reduced levels of neutrophils and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and lung tissue. Intriguingly, the ameliorative effects were abolished upon the depletion of monocyte-derived alveolar macrophages (Mo-AMs) rather than tissue-resident alveolar macrophages (TR-AMs). JAK2 deficiency markedly reversed LPS-induced activation of STAT5 in macrophages. Remarkably, pharmacological JAK2 inhibition using baricitinib failed to substantially alleviate neutrophils infiltration, implying that specific inhibition of JAK2 in Mo-AMs is imperative for ARDS amelioration. Collectively, our data suggest that JAK2 may mitigate ARDS progression through the JAK2 pathway in Mo-AMs, underscoring JAK2 in alveolar macrophages, particularly Mo-AMs, as a promising therapeutic target for ARDS treatment.

IL-1β mediated fibroblast-neutrophil crosstalk promotes inflammatory environment in skin lesions of SLE

Systemic lupus erythematosus (SLE) is characterized by immune dysregulation, with neutrophil infiltration in skin lesions contributing to inflammation and disease progression. However, the interaction between fibroblasts and neutrophils in SLE skin lesions has not been fully explored. Using single-cell RNA sequencing, we identified a unique CXCL1+ fibroblast subset in SLE lesions. We found that CXCL1+ fibroblasts recruit and activate neutrophils, increasing the production of inflammatory mediators, reactive oxygen species, and neutrophil extracellular traps. These fibroblasts also facilitated the transition of neutrophils to a low-density phenotype. Notably, these fibroblasts delayed neutrophil apoptosis, extending their survival and amplifying inflammation. Serum amyloid A1, secreted by CXCL1+ fibroblasts, emerged as a key activator of neutrophils. Activated neutrophils, in turn, secreted IL-1β to induce CXCL1+ fibroblasts differentiation via activating the NF-κB pathway. In conclusion, our findings reveal that IL-1β-induced CXCL1+ fibroblasts significantly modulate pro-inflammatory neutrophils, underscoring the critical crosstalk between fibroblasts and neutrophils in SLE pathogenesis.

Conquering dual challenges: A sialic-modified liposome for targeting activated neutrophils to tackle comorbid lung inflammation and cancer metastasis

In clinical settings, cancer frequently coexists with multi-system diseases. Owing to compromised immune systems, patients with cancer exhibit an increased susceptibility to infections and inflammation. Notably, lung inflammation occurs with high incidence among these patients. Furthermore, the inflammatory milieu within the lungs often accelerates the metastasis of cancer, thereby enhancing mortality rates and posing substantial challenges for clinical management. To date, effective strategies addressing both lung inflammation and cancer concurrently are lacking. In this context, we introduce a novel therapeutic approach involving a sialic acid-lipid derivative (SA-PG10-C18) modified doxorubicin-curcumin co-loaded liposome (DOX/CUR-SAL). This formulation effectively targeted activated neutrophils, which are abundantly present in inflammatory and metastatic lung tissues. DOX/CUR-SAL notably inhibited neutrophil-mediated pro-inflammatory and pro-metastatic processes. Utilizing a newly established mouse model of acute lung injury (ALI) and metastasis comorbidity, DOX/CUR-SAL modulated the lung immune microenvironment and arrested the progression of both inflammation and metastasis, without inducing side effects. The treated animals demonstrated favorable survival conditions, persisting beyond 45 days. This innovative therapeutic strategy offers a novel concept and reference for treating comorbid conditions of tumors and inflammation, thus breaking the clinical impasse where lung inflammation and cancer metastasis have been treated separately.

Blockade of the CCR3 receptor reduces neutrophil recruitment to the lung during acute inflammation

Neutrophils represent one of the host's first lines of defense against invading pathogens. However, an aberrant activation can cause damage to the host. In the case of respiratory infections with viral or bacterial pathogens, one of the most common complications is the development of acute respiratory distress syndrome, in which neutrophil infiltration into the lung is a hallmark. Neutrophils gain expression of chemokine receptors under inflammatory conditions, and their activation can amplify the neutrophil responses. Earlier studies showed that neutrophils recruited to the lung mucosa during bacterial infection upregulate expression of CCR3 and ex vivo stimulation of CCR3 results in an increased neutrophil activation. Therefore, the modulation of effector functions or migration of neutrophils to target sites through chemokine receptors constitutes an opportunity for pharmacological intervention. We aimed to determine whether the blockade of the CCR3 using the specific antagonist SB-328437 reduces neutrophil recruitment and inflammation in the lung in the lipopolysaccharide (LPS)-induced lung injury model and influenza infection in mice. We found that neutrophils acquire CCR3 expression in the lung alveolar space. The intraperitoneal administration of SB-328437 reduced neutrophil recruitment to the lung alveolar space and reduced tissue damage in both the LPS-induced lung injury model and influenza infection. Moreover, treatment with SB-328437 reduced the percentage of neutrophils producing TNFα and neutrophil activation in the alveolar space. Together, these data suggest that CCR3 blockade might be a pharmacological strategy to prevent the aberrant neutrophil activation that results detrimental for the host but preserves sufficient effector response to control the pathogen.

Deep Learning and Single-Cell Sequencing Analyses Unveiling Key Molecular Features in the Progression of Carotid Atherosclerotic Plaque

Rupture of advanced carotid atherosclerotic plaques increases the risk of ischaemic stroke, which has significant global morbidity and mortality rates. However, the specific characteristics of immune cells with dysregulated function and proven biomarkers for the diagnosis of atherosclerotic plaque progression remain poorly characterised. Our study elucidated the role of immune cells and explored diagnostic biomarkers in advanced plaque progression using single-cell RNA sequencing and high-dimensional weighted gene co-expression network analysis. We identified a subcluster of monocytes with significantly increased infiltration in the advanced plaques. Based on the monocyte signature and machine-learning approaches, we accurately distinguished advanced plaques from early plaques, with an area under the curve (AUC) of 0.899 in independent external testing. Using microenvironment cell populations (MCP) counter and non-negative matrix factorisation, we determined the association between monocyte signatures and immune cell infiltration as well as the heterogeneity of the patient. Finally, we constructed a convolutional neural network deep learning model based on gene-immune correlation, which achieved an AUC of 0.933, a sensitivity of 92.3%, and a specificity of 87.5% in independent external testing for diagnosing advanced plaques. Our findings on unique subpopulations of monocytes that contribute to carotid plaque progression are crucial for the development of diagnostic tools for clinical diseases.

Progress in cytokine research for ARDS: A comprehensive review

Introduction

Acute respiratory distress syndrome (ARDS) is a critical form of acute respiratory failure characterized by diffuse alveolar damage, refractory hypoxemia, and non-cardiogenic pulmonary edema, resulting in high mortality. Dysregulated inflammation, driven by cytokines, is central to ARDS pathogenesis, progression, and prognosis.

Objective

This review synthesizes current knowledge on the role of cytokines in ARDS and evaluates their potential as therapeutic targets, offering new insights for clinical management.

Methods

A comprehensive analysis of recent studies was conducted to explore the roles of pro-inflammatory cytokines (e.g., IL-1β, IL-6, IL-8) and anti-inflammatory cytokines (e.g., IL-10, IL-22) in ARDS pathogenesis and to assess current and emerging therapies targeting these cytokines.

Results

Pro-inflammatory cytokines are crucial in initiating inflammatory responses and lung injury in early ARDS, while anti-inflammatory cytokines help regulate and resolve inflammation. Targeted therapies, such as IL-1 and IL-6 inhibitors, show potential in managing ARDS, particularly in COVID-19, but their clinical efficacy is still debated. Combination therapy strategies may enhance outcomes, but further large-scale, multicenter randomized controlled trials are required to establish their safety and efficacy.

Conclusion

Understanding cytokine regulation in ARDS could lead to innovative therapeutic approaches. Future research should focus on cytokine roles across ARDS subtypes and stages and develop biomarker-driven, individualized treatments.

Atractylodin modulates ASAH3L to improve galactose metabolism and inflammation to alleviate acute lung injury

Acute lung injury (ALI) is a lung disease characterized by an excessive inflammatory response and damage to lung epithelial cells. Atractylodin (ATL) has good anti-inflammatory activity and protects the integrity of the epithelial cell barrier. However, the efficacy of ATL in the treatment of ALI and its mechanism is unclear. We investigated the efficacy of ATL in treating ALI and explored its targets and mechanisms. The results showed that ATL significantly reduced the wet-dry ratio of lungs of rats with ALI, improved the pathological changes, and lowered the expression of the inflammatory factors. Combined metabolomic and transcriptomic analyses showed that ATL can reduce inflammation by inhibiting and activating the HIF-1 signaling pathway and modulating ASAH3L to improve galactose metabolism, thereby alleviating ALI. In conclusion, ATL may be a potential drug for the treatment of acute lung injury.

Endothelial Cell-Derived Extracellular Vesicles Promote Aberrant Neutrophil Trafficking and Subsequent Remote Lung Injury

The development of acute respiratory distress syndrome (ARDS) in sepsis is associated with substantial morbidity and mortality. However, the molecular pathogenesis underlying sepsis-induced ARDS remains elusive. Neutrophil heterogeneity and dysfunction contribute to uncontrolled inflammation in patients with ARDS. A specific subset of neutrophils undergoing reverse transendothelial migration (rTEM), which is characterized by an activated phenotype, is implicated in the systemic dissemination of inflammation. Using single-cell RNA sequencing (scRNA-seq), it identified functionally activated neutrophils exhibiting the rTEM phenotype in the lung of a sepsis mouse model using cecal ligation and puncture. The prevalence of neutrophils with the rTEM phenotype is elevated in the blood of patients with sepsis-associated ARDS and is positively correlated with disease severity. Mechanically, scRNA-seq and proteomic analys revealed that inflamed endothelial cell (EC) released extracellular vesicles (EVs) enriched in karyopherin subunit beta-1 (KPNB1), promoting abluminal-to-luminal neutrophil rTEM. Additionally, EC-derived EVs are elevated and positively correlated with the proportion of rTEM neutrophils in clinical sepsis. Collectively, EC-derived EV is identified as a critical regulator of neutrophil rTEM, providing insights into the contribution of rTEM neutrophils to sepsis-associated lung injury.

MFSD7C protects hemolysis-induced lung impairments by inhibiting ferroptosis

Hemolysis drives susceptibility to lung injury and predicts poor outcomes in diseases, such as malaria and sickle cell disease (SCD). However, the underlying pathological mechanism remains elusive. Here, we report that major facilitator superfamily domain containing 7 C (MFSD7C) protects the lung from hemolytic-induced damage by preventing ferroptosis. Mechanistically, MFSD7C deficiency in HuLEC-5A cells leads to mitochondrial dysfunction, lipid remodeling and dysregulation of ACSL4 and GPX4, thereby enhancing lipid peroxidation and promoting ferroptosis. Furthermore, systemic administration of MFSD7C mRNA-loaded nanoparticles effectively prevents lung injury in hemolytic mice, such as HbSS-Townes mice and PHZ-challenged 7 C-/- mice. These findings present the detailed link between hemolytic complications and ferroptosis, providing potential therapeutic targets for patients with hemolytic disorders.

Inflammatory response to SARS-CoV 2 and other respiratory viruses

INTRODUCTION

Lower respiratory tract infections (LRTI) remain a significant global cause of mortality and disability. Viruses constitute a substantial proportion of LRTI cases, with their pandemic potential posing a latent threat. After the SARS-CoV-2 pandemic, the resurgence of other respiratory viruses, including Influenza and Respiratory Syncytial Virus responsible for LRTI has been observed especially in susceptible populations.

AREAS COVERED

This review details the inflammatory mechanisms associated with three primary respiratory viruses: SARS-CoV-2, Influenza, and Respiratory Syncytial Virus (RSV). The focus will be on elucidating the activation of inflammatory pathways, understanding cellular contributions to inflammation, exploring the role of interferon and induced cell death in the response to these pathogens and detailing viral evasion mechanisms. Furthermore, the distinctive characteristics of each virus will be explained.

EXPERT OPINION

The study of viral pneumonia, notably concerning SARS-CoV-2, Influenza, and RSV, offers critical insights into infectious and inflammatory mechanisms with wide-ranging implications. Addressing current limitations, such as diagnostic accuracy and understanding host-virus interactions, requires collaborative efforts and investment in technology. Future research holds promise for uncovering novel therapeutic targets, exploring host microbiome roles, and addressing long-term sequelae. Integrating advances in molecular biology and technology will shape the evolving landscape of viral pneumonia research, potentially enhancing global public health outcomes.

Mitochondrial perturbations in low-protein-diet-fed mice are associated with altered neutrophil development and effector functions

Severe malnutrition is associated with infections, namely lower respiratory tract infections (LRTIs), diarrhea, and sepsis, and underlies the high risk of morbidity and mortality in children under 5 years of age. Dysregulations in neutrophil responses in the acute phase of infection are speculated to underlie these severe adverse outcomes; however, very little is known about their biology in this context. Here, in a lipopolysaccharide-challenged low-protein diet (LPD) mouse model, as a model of malnutrition, we show that protein deficiency disrupts neutrophil mitochondrial dynamics and ATP generation to obstruct the neutrophil differentiation cascade. This promotes the accumulation of atypical immature neutrophils that are incapable of optimal antimicrobial response and, in turn, exacerbate systemic pathogen spread and the permeability of the alveolocapillary membrane with the resultant lung damage. Thus, this perturbed response may contribute to higher mortality risk in malnutrition. We also offer a nutritional therapeutic strategy, nicotinamide, to boost neutrophil-mediated immunity in LPD-fed mice.

Hub genes identification and validation of ferroptosis in SARS-CoV-2 induced ARDS: perspective from transcriptome analysis

Introduction

Acute Respiratory Distress Syndrome (ARDS) poses a significant health challenge due to its high incidence and mortality rates. The emergence of SARS-CoV-2 has added complexity, with evidence suggesting a correlation between COVID-19 induced ARDS and post-COVID symptoms. Understanding the underlying mechanisms of ARDS in COVID-19 patients is crucial for effective clinical treatment.

Method

To investigate the potential role of ferroptosis in SARS-CoV-2 induced ARDS, we conducted a comprehensive analysis using bioinformatics methods. Datasets from the Gene Expression Omnibus (GEO) were utilized, focusing on COVID-19 patients with varying ARDS severity. We employed weighted gene co-expression network analysis (WGCNA), differential gene expression analysis, and single-cell sequencing to identify key genes associated with ferroptosis in ARDS. Hub genes were validated using additional GEO datasets and cell experiment.

Result

The analysis discerned 916 differentially expressed genes in moderate/severe ARDS patients compared to non-critical individuals. Weighted Gene Co-expression Network Analysis (WGCNA) unveiled two modules that exhibited a positive correlation with ARDS, subsequently leading to the identification of 15 hub genes associated with ferroptosis. Among the noteworthy hub genes were MTF1, SAT1, and TXN. Protein-protein interaction analysis, and pathway analysis further elucidated their roles. Immune infiltrating analysis highlighted associations between hub genes and immune cells. Validation in additional datasets confirmed the upregulation of MTF1, SAT1, and TXN in SARS-CoV-2-induced ARDS. This was also demonstrated by qRT-PCR results in the BEAS-2B cells vitro model, suggesting their potential as diagnostic indicators.

Discussion

This study identifies MTF1, SAT1, and TXN as hub genes associated with ferroptosis in SARS-CoV-2-induced ARDS. These findings provide novel insights into the molecular mechanisms underlying ARDS in COVID-19 patients and offer potential targets for immune therapy and targeted treatment. Further experimental validation is warranted to solidify these findings and explore therapeutic interventions for ARDS in the context of COVID-19.

Schistosoma japonicum cystatin alleviates paraquat poisoning caused acute lung injury in mice through activating regulatory macrophages

BACKGROUND

Paraquat (PQ) is a widely used herbicide that poisons human by accident or intentional ingestion. PQ poisoning causes systemic inflammatory response syndrome (SIRS) resulting in acute lung injury (ALI) with an extremely high mortality rate. Blood trematode Schistosoma japonicum-produced cystatin (Sj-Cys) is a strong immunomodulatory protein that has been experimentally used to treat inflammation related diseases. In this study, Sj-Cys recombinant protein (rSj-Cys) was used to treat PQ-induced lung injury and the immunological mechanism underlying the therapeutic effect was investigated.

METHODS

PQ-induced acute lung injury mouse model was established by intraperitoneally injection of 20 mg/kg of paraquat. The poisoned mice were treated with rSj-Cys and the survival rate was observed up to 7 days compared with the group without treatment. The pathological changes of PQ-induced lung injury were observed by examining the histochemical sections of affected lung tissue and the wet to dry ratio of lung as a parameter for inflammation and edema. The levels of the inflammation related cytokines IL-6 and TNF-α and regulatory cytokines IL-10 and TGF-β were measured in sera and in affected lung tissue using ELISA and their mRNA levels in lung tissue using RT-PCR. The macrophages expressing iNOS were determined as M1 and those expressing Arg-1 as M2 macrophages. The effect of rSj-Cys on the transformation of inflammatory M1 to regulatory M2 macrophages was measured in affected lung tissue in vivo (EKISA and RT-PCR) and in MH-S cell line in vitro (flow cytometry). The expression levels of TLR2 and MyD88 in affected lung tissue were also measured to determine their role in the therapy of rSj-Cys on PQ-induced lung injury.

RESULT

We identified that treatment with rSj-Cys significantly improved the survival rate of mice with PQ-induced lung injury from 30 % (untreated) to 80 %, reduced the pathological damage of poisoning lung tissue, associated with significantly reduced levels of proinflammatory cytokines (IL-6 from 1490 to 590 pg/ml, TNF-α from 260 to 150 pg/ml) and increased regulatory cytokines (IL-10 from360 to 550 pg/ml, and TGF-β from 220 to 410 pg/ml) in both sera (proteins) and affected lung tissue (proteins and mRNAs). The polarization of macrophages from M1to M2 type was found to be involved in the therapeutic effect of rSj-Cys on the PQ-induced acute lung injury, possibly through inhibiting TLR2/MyD88 signaling pathway.

CONCLUSIONS

Our study demonstrated the therapeutic effect of rSj-Cys on PQ poisoning caused acute lung injury by inducing M2 macrophage polarization through inhibiting TLR2/MyD88 signaling pathway. The finding in this study provides an alternative approach for the treatment of PQ poisoning and other inflammatory diseases.

CPT1A-IL-10-mediated macrophage metabolic and phenotypic alterations ameliorate acute lung injury

BACKGROUND

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common acute respiratory failure due to diffuse pulmonary inflammation and oedema. Elaborate regulation of macrophage activation is essential for managing this inflammatory process and maintaining tissue homeostasis. In the past decades, metabolic reprogramming of macrophages has emerged as a predominant role in modulating their biology and function. Here, we observed reduced expression of carnitine palmitoyltransferase 1A (CPT1A), a key rate-limiting enzyme of fatty acid oxidation (FAO), in macrophages of lipopolysaccharide (LPS)-induced ALI mouse model. We assume that CPT1A and its regulated FAO is involved in the regulation of macrophage polarization, which could be positive regulated by interleukin-10 (IL-10).

METHODS

After nasal inhalation rIL-10 and/or LPS, wild type (WT), IL-10-/-, Cre-CPT1Afl/fl and Cre+CPT1Afl/fl mice were sacrificed to harvest bronchoalveolar lavage fluid, blood serum and lungs to examine cell infiltration, cytokine production, lung injury severity and IHC. Bone marrow-derived macrophages (BMDMs) were extracted from mice and stimulated by exogenous rIL-10 and/or LPS. The qRT-PCR, Seahorse XFe96 and FAO metabolite related kits were used to test the glycolysis and FAO level in BMDMs. Immunoblotting assay, confocal microscopy and fluorescence microplate were used to test macrophage polarization as well as mitochondrial structure and function damage.

RESULTS

In in vivo experiments, we found that mice lacking CPT1A or IL-10 produced an aggravate inflammatory response to LPS stimulation. However, the addition of rIL-10 could alleviate the pulmonary inflammation in mice effectively. IHC results showed that IL-10 expression in lung macrophage decreased dramatically in Cre+CPT1Afl/fl mice. The in vitro experiments showed Cre+CPT1Afl/fl and IL-10-/- BMDMs became more "glycolytic", but less "FAO" when subjected to external attacks. However, the supplementation of rIL-10 into macrophages showed reverse effect. CPT1A and IL-10 can drive the polarization of BMDM from M1 phenotype to M2 phenotype, and CPT1A-IL-10 axis is also involved in the process of maintaining mitochondrial homeostasis.

CONCLUSIONS

CPT1A modulated metabolic reprogramming and polarisation of macrophage under LPS stimulation. The protective effects of CPT1A may be partly attributed to the induction of IL-10/IL-10 receptor expression.

Activated Clec4nhi Neutrophils Aggravate Lung Injury in an Endothelial IGFBP7-Dependent Manner

The role of endothelial cells in acute lung injury (ALI) has been widely elaborated, but little is known about the role of different subtypes of endothelial cells in ALI. ALI models were established by lipopolysaccharide. Single-cell RNA sequencing was used to identify differential molecules in endothelial subtypes and the heterogeneity of lung immune cells. Specific antibodies were used to block insulin-like growth factor binding protein 7 (IGFBP7), and AAVshIGP7 was used to specifically knock down IGFBP7. Here, we found that IGFBP7 was the most differentially expressed molecule in diverse subsets of endothelial cells and that IGFBP7 was strongly associated with inflammatory responses. Elevated IGFBP7 significantly exacerbated barrier dysfunction in ALI, whereas blockade of IGFBP7 partially reversed barrier damage. General capillary cells are the primary source of elevated serum IGFBP7 after ALI. Using single-cell RNA sequencing, we identified significantly increased Clec4nhi neutrophils in mice with ALI, whereas IGFBP7 knockdown significantly reduced infiltration of Clec4nhi cells and mitigated barrier dysfunction in ALI. In addition, we found that IGFBP7 activated the NF-κB signaling axis by promoting phosphorylation and ubiquitination degradation of F-box/WD repeat-containing protein 2 (FBXW2), thereby exacerbating barrier dysfunction in ALI. Taken together, our data indicate that blockade of serum IGFBP7 or IGFBP7 depletion in general capillary cells reversed barrier damage in ALI. Therefore, targeting IGFBP7 depletion could be a novel strategy for treating ALI.

IL-10 Counteracts IFN-γ to Alleviate Acute Lung Injury in a Viral-Bacterial Superinfection Model

Immune activation is essential for lung control of viral and bacterial infection, but an overwhelming inflammatory response often leads to the onset of acute respiratory distress syndrome. IL-10 plays a crucial role in regulating the balance between antimicrobial immunity and immunopathology. In the present study, we investigated the role of IL-10 in acute lung injury induced by influenza A virus and methicillin-resistant Staphylococcus aureus coinfection. This unique coinfection model resembles patients with acute pneumonia undergoing appropriate antibiotic therapies. Using global IL-10 and IL-10 receptor gene-deficient mice, as well as in vivo neutralizing antibodies, we show that IL-10 deficiency promotes IFN-γ-dominant cytokine responses and triggers acute animal death. Interestingly, this extreme susceptibility is fully preventable by IFN-γ neutralization during coinfection. Further studies using mice with Il10ra deletion in selective myeloid subsets reveal that IL-10 primarily acts on mononuclear phagocytes to prevent IFN-γ/TNF-α hyperproduction and acute mortality. Importantly, this antiinflammatory IL-10 signaling is independent of its inhibitory effect on antiviral and antibacterial defense. Collectively, our results demonstrate a key mechanism of IL-10 in preventing hypercytokinemia and acute respiratory distress syndrome pathogenesis by counteracting the IFN-γ response.

Amplifying protection against acute lung injury: Targeting both inflammasome and cGAS-STING pathway by Lonicerae Japonicae Flos-Forsythiae Fructus drug pair

Objective

Acute lung injury (ALI) is characterized by inflammation and currently lacks an efficacious pharmacological intervention. The medicine combination of Lonicerae Japonicae Flos (LJF) and Forsythiae Fructus (FF) demonstrates combined properties in its anti-infective, anti-inflammatory, and therapeutic effects, particularly in alleviating respiratory symptoms. In previous studies, Chinese medicine has shown promising efficacy in lipopolysaccharides (LPS)-induced ALI. However, there have been no reports of LJF and FF pairing for lung injury. The aim of this study is to compare the efficacy of herb pair Lonicerae Japonicae Flos-Forsythiae Fructus (LF) with LJF or FF alone in the treatment of ALI, and to explore whether LJF and FF have a combined effect in the treatment of lung injury, along with the underlying mechanism involved.

Methods

A total of 36 mice were divided into six groups (control, model, LJF, FF, LF, dexamethasone) based on the treatments they received after undergoing sham-operation/LPS tracheal instillation. H&E staining and pulmonary edema indexes were used to evaluate lung injury severity. Alveolar exudate cells (AECs) were counted based on cell count in bronchoalveolar lavage fluid (BALF), and neutrophil percentage in BALF was measured using flow cytometry. Myeloperoxidase (MPO) activity in BALF was measured using enzyme-linked immunosorbent assay (ELISA), while the production of IL-1β, TNF-α, and IL-6 in the lung and secretion level of them in BALF were detected by quantitative polymerase chain reaction (qPCR) and ELISA. The effect of LJF, FF, and LF on the expression of Caspase-1 and IL-1β proteins in bone marrow derived macrophages (BMDMs) supernatant was assessed using Western blot method under various inflammasome activation conditions. In addition, the concentration of IL-1β and changes in lactatedehydrogenase (LDH) release levels in BMDMs supernatant after LJF, FF, and LF administration, respectively, were measured using ELISA. Furthermore, the effects of LJF, FF and LF on STING and IRF3 phosphorylation in BMDMs were detected by Western blot, and the mRNA changes of IFN-β, TNF-α, IL-6 and CXCL10 in BMDMs were detected by qPCR.

Results

LF significantly attenuated the damage to alveolar structures, pulmonary hemorrhage, and infiltration of inflammatory cells induced by LPS. This was evidenced by a decrease in lung index score and wet/dry weight ratio. Treatment with LF significantly reduced the total number of neutrophil infiltration by 75% as well as MPO activity by 88%. The efficacy of LF in reducing inflammatory factors IL-1β, TNF-α, and IL-6 in the lungs surpasses that of LJF or FF, approaching the effectiveness of dexamethasone. In BMDMs, the co-administration of 0.2 mg/mL of LJF and FF demonstrated superior inhibitory effects on the expression of nigericin-stimulated Caspase-1 and IL-1β, as well as the release levels of LDH, compared to individual treatments. Similarly, the combination of 0.5 mg/mL LJF and FF could better inhibit the phosphorylation levels of STING and IRF3 and the production of IFN-β, TNF-α, IL-6, and CXCL10 in response to ISD stimulation.

Conclusion

The combination of LJF and FF increases the therapeutic effect on LPS-induced ALI, which may be mechanistically related to the combined effect inhibition of cyclic-GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) and NOD-like receptor family protein 3 (NLRP3) inflammasomes pathways by LJF and FF. Our study provides new medicine candidates for the clinical treatment of ALI.

Ultrashort wave diathermy inhibits pulmonary inflammation in mice with acute lung injury in a HSP70 independent way: a pilot study

BACKGROUND

Acute lung injury (ALI) is a clinical syndrome characterized by pulmonary inflammation. Ultrashort wave diathermy (USWD) has been shown to be effective at in inhibiting ALI inflammation, although the underlying mechanism remains unclear. Previous studies have demonstrated that USWD generates a therapeutic thermal environment that aligns with the temperature required for heat shock protein 70 (HSP70), an endogenous protective substance. In this study, we examined the correlation between HSP70 and USWD in alleviating lung inflammation in ALI.

METHODS

Forty-eight male C57BL/6 mice were randomly divided into control, model, USWD intervention (LU) 1, 2, and 3, and USWD preintervention (UL) 1, 2, and 3 groups (n = 6 in each group). The mice were pretreated with LPS to induce ALI. The UL1, 2, and 3 groups received USWD treatment before LPS infusion, while the LU1, 2, and 3 groups received USWD treatment after LPS infusion. Lung function and structure, inflammatory factor levels and HSP70 protein expression levels were detected.

RESULTS

USWD effectively improved lung structure and function, and significantly reduced IL-1β, IL-10, TGF-β1, and TNF-α levels in both the USWD preintervention and intervention groups. However, HSP70 expression did not significantly differ across the experimental groups although the expression of TLR4 was significantly decreased, suggesting that USWD may have anti-inflammatory effects through multiple signaling pathways or that the experimental conditions should be restricted.

CONCLUSIONS

Both USWD intervention and preintervention effectively reduced the inflammatory response, alleviated lung injury symptoms, and played a protective role in LPS-pretreated ALI mice. HSP70 was potentially regulated by USWD in this process, but further studies are urgently needed to elucidate the correlation and mechanism.

Bioinformatics analyses and experimental validation of ferroptosis-related genes in bronchopulmonary dysplasia pathogenesis

OBJECTIVE

We aimed to study the involvement of ferroptosis in the pathogenesis of bronchopulmonary dysplasia (BPD) by conducting bioinformatics analyses and identifying and validating the associated ferroptosis-related genes to explore new directions for treating BPD.

METHODS

The dataset GSE32472 on BPD was downloaded from the public genome database. Using R language, differentially expressed genes (DEGs) between the BPD and normal group were screened. In the present study, we adopted weighted gene correlation network analysis (WGCNA) for identifying BPD-related gene modules and ferroptosis-related genes were extracted from FerrDb. Their results were intersected to obtain the hub genes. After that, to explore the hub gene-related signaling pathways, the hub genes were exposed to gene ontology enrichment analysis. With the purpose of verifying the mRNA expression of the hub genes, a single-gene gene set enrichment analysis and quantitative reverse transcription polymerase chain reaction were conducted. Immune cell infiltration in BPD was analyzed using the CIBERSORT inverse fold product algorithm.

RESULTS

A total of 606 DEGs were screened. WGCNA provided the BPD-related gene module darkgreen4. The intersection of DEGs, intramodular genes, and ferroptosis-related genes revealed six ferroptosis-associated hub genes (ACSL1, GALNT14, WIPI1, MAPK14, PROK2, and CREB5). Receiver operating characteristic curve analysis demonstrated that the hub genes screened for BPD were of good diagnostic significance. According to the results of immune infiltration analysis, the proportions of CD8, CD4 naive, and memory resting T cells and M2 macrophage were elevated in the normal group, and the proportions of M0 macrophage, resting mast cell, and neutrophils were increased in the BPD group.

CONCLUSIONS

A total of six ferroptosis-associated hub genes in BPD were identified in this study, and they may be potential new therapeutic targets for BPD.

Xiebai San alleviates acute lung injury by inhibiting the phosphorylation of the ERK/Stat3 pathway and regulating multiple metabolisms

BACKGROUND

Acute lung injury (ALI) often leads to serious respiratory diseases with high incidence rates and mortality. For centuries, Xiebai San (XBS) has been a classical traditional Chinese medicine (TCM) about respiratory illness such as pneumonia in children. However, the related mechanism of XBS against ALI remains indistinct.

PURPOSE

To reveal specific targets of XBS in lipopolysaccharide (LPS)-induced ALI mice using integrated pharmacology.

STUDY DESIGN

The integrated method was to expound mechanism and targets of XBS inhibited ALI.

METHODS

The primary components in XBS were identified by ultra high performance liquid chromatography-quadrupole time of flight-mass spectrometry (UHPLC-QTOF-MS). The potential drug targets were established using network pharmacology. The anti-ALI effect of XBS was evaluated in mice. Additionally, therapeutic targets were screened by integrating metabolome and transcriptome and verified in lung tissue.

RESULTS

In total, 163 chemical components were identified in XBS, and a network of "3 drugs-18 components-86 targets" for XBS against ALI was constructed. In ALI mice, XBS alleviated lung inflammation by decreasing permeation and expression of neutrophils, tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in bronchoalveolar lavage fluid (BALF), serum, and lung tissue. Next, the transcriptome of lung tissue was analyzed and enriched, indicating the importance of mitogen-activated protein kinase (MAPK), Janus kinase-signal transducer and activator of transcription (JAK-STAT), and others, which was consistent with network pharmacology prediction. Also, western blotting and immunohistochemistry results showed that XBS was against ALI mainly by inhibiting extracellular signal regulated kinase (ERK) and signal transducer and activator of transcription 3 (Stat3) phosphorylation. In addition, the metabolome of lung tissue revealed that XBS mainly regulated pathways involved in arachidonic acid, glycerophospholipid, and tryptophan metabolisms. The expression levels of leukotriene, phosphatidylcholine, kynurenine, and others were also verified.

CONCLUSION

XBS alleviated inflammation of ALI by inhibiting the phosphorylation of the ERK/Stat3 pathway and regulating arachidonic acid, glycerophospholipid, and tryptophan metabolisms. This study will guide clinical precision medicine and promote modernization of XBS.

Exploring immune-related pathogenesis in lung injury: Providing new insights Into ALI/ARDS

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a significant global burden of morbidity and mortality, with lung injury being the primary cause of death in affected patients. The pathogenesis of lung injury, however, remains a complex issue. In recent years, the role of the immune system in lung injury has attracted extensive attention worldwide. Despite advancements in our understanding of various lung injury subtypes, significant limitations persist in both prevention and treatment. This review investigates the immunopathogenesis of ALI/ARDS, aiming to elucidate the pathological processes of lung injury mediated by dendritic cells (DCs), natural killer (NK) cells, phagocytes, and neutrophils. Furthermore, the article expounds on the critical contributions of gut microbiota, inflammatory pathways, and cytokine storms in the development of ALI/ARDS.

Endothelial ERG programs neutrophil transcriptome for sustained anti-inflammatory vascular niche

Neutrophils (PMNs) reside as a marginated pool within the vasculature, ready for deployment during infection. However, how endothelial cells (ECs) control PMN extravasation and activation to strengthen tissue homeostasis remains ill-defined. Here, we found that the vascular ETS-related gene (ERG) is a generalized mechanism regulating PMN activity in preclinical tissue injury models and human patients. We show that ERG loss in ECs rewired PMN-transcriptome, enriched for genes associated with the CXCR2-CXCR4 signaling. Rewired PMNs compromise mice survival after pneumonia and induced lung vascular inflammatory injury following adoptive transfer into naïve mice, indicating their longevity and inflammatory activity memory. Mechanistically, EC-ERG restricted PMN extravasation and activation by upregulating the deubiquitinase A20 and downregulating the NFκB-IL8 cascade. Rescuing A20 in EC-Erg -/- endothelium or suppressing PMN-CXCR2 signaling rescued EC control of PMN activation. Findings deepen our understanding of EC control of PMN-mediated inflammation, offering potential avenues for targeting various inflammatory diseases.

Highlights

ERG regulates trans-endothelial neutrophil (PMN) extravasation, retention, and activationLoss of endothelial (EC) ERG rewires PMN-transcriptomeAdopted transfer of rewired PMNs causes inflammation in a naïve mouse ERG transcribes A20 and suppresses CXCR2 function to inactivate PMNs.

In brief/blurb

The authors investigated how vascular endothelial cells (EC) control polymorphonuclear neutrophil (PMN) extravasation, retention, and activation to strengthen tissue homeostasis. They showed that EC-ERG controls PMN transcriptome into an anti-adhesive and anti-inflammatory lineage by synthesizing A20 and suppressing PMNs-CXCR2 signaling, defining EC-ERG as a target for preventing neutrophilic inflammatory injury.

ANALYSIS AND IDENTIFICATION OF FERROPTOSIS-RELATED GENE SIGNATURE FOR ACUTE LUNG INJURY

ABSTRACT

Background: Recent studies have shown that ferroptosis is involved in the evolution of acute lung injury (ALI), a serious respiratory pathological process leading to death. However, the regulatory mechanisms underlying ferroptosis in ALI remain largely unknown. The current study analyzed and identified a ferroptosis-related gene signature for ALI. Methods: Key genes associated with ferroptosis in ALI were identified by bioinformatics analysis. GSE104214, GSE18341, and GSE17355 datasets were downloaded from the Gene Expression Omnibus database. The signature genes were screened by least absolute shrinkage and selection operator regression, and the key genes of ALI were screened by weighted correlation network analysis (WGCNA), followed by immune infiltration analysis and functional enrichment analysis. In addition, mRNA expression of key genes in the lungs of mice with hemorrhagic shock (HS) and sepsis was verified. Results: A total of 2,132 differential genes were identified by various analyses, and 9 characteristic genes were detected using Lasso regression. We intersected nine signature genes with WGCNA module genes and finally determined four key genes ( PROK2 , IL6 , TNF , SLC7A11 ). All four key genes were closely correlated with immune cells and regulatory genes of ALI, and the expression of the four genes was significantly different in the lung tissues of HS and sepsis models. Besides, the ferroptosis-related molecules GPX4 and ACSL4 showed remarkable difference in these models. Conclusion: These results indicate that PROK2 , IL6 , TNF , and SLC7A11 may be key regulatory targets of ferroptosis during ALI. This study proved that ferroptosis is a common pathophysiological process in three ALI models.