Role of TNFalpha in pulmonary pathophysiology

The Restoring Effect of Human Umbilical Cord-Derived Mesenchymal Cell-Conditioned Medium (hMSC-CM) against Carbon Tetrachloride-Induced Pulmonary Fibrosis in Male Wistar Rats

Objective

Pulmonary toxicity induced by CCl₄, a model of idiopathic pulmonary fibrosis (IPF), leads to tissue remodeling and inflammation. Human umbilical cord mesenchymal cell-conditioned medium (hMSC-CM) is a potent anti-inflammatory, antioxidative, and antifibrotic agent.

Methods

Forty male Wistar rats were assigned to the control (C), olive oil control (C.O) (hMSC-CM), control (C.Ms), fibrosis (fb), and fibrosis with hMSC-CM (f.Ms) treatment groups. The groups C, C.O, and C.Ms received PBS (200 µl), olive oil (1 ml/kg), and hMSC-CM (100 μg protein/kg), respectively. The fibrosis group was administered with only CCl4 (1 ml/kg). The last group, f.Ms was treated with CCl₄ (1 ml/kg) and 100 μg protein/kg IV hMSC-CM. While the treatment with olive oil and CCl₄ was performed for 2 days/week from the first week for 12 weeks, the treatment with PBS and hMSC-CM was carried out 2 days/week from week 4^th to week 12^th. The effect of the UC-MSC culture medium treatment on the lung was evaluated by assessing lysyl oxidase (LOX), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-β1 (TGF-β1) genes, and proteins expression by real-time RCR and western blotting, respectively.

Results

Lysyl oxidase (LOX), tumor necrosis factor-alpha (TNF-α), transforming growth factor-b1 (TGF-β1), malondialdehyde (MDA), and oxidative stress levels were markedly higher in the fibrosis group than in the control groups (p ≤ 0.001). Additionally, glutathione (GSH) in the fibrosis group was markedly lower than those in the control groups (p ≤ 0.001). Fibrosis in the UC-MSC treatment group had milder histopathological injuries than in the fibrosis group.

Conclusion

hMSC-MSC as a strong anti-inflammatory, antioxidative, and antifibrotic decreases the level of oxidative stress, proinflammatory cytokines, and MDA causing a restoring effect against CCl₄-induced pulmonary fibrosis.

Specific S100 Proteins Bind Tumor Necrosis Factor and Inhibit Its Activity

Tumor necrosis factor (TNF) inhibitors (anti-TNFs) represent a cornerstone of the treatment of various immune-mediated inflammatory diseases and are among the most commercially successful therapeutic agents. Knowledge of TNF binding partners is critical for identification of the factors able to affect clinical efficacy of the anti-TNFs. Here, we report that among eighteen representatives of the multifunctional S100 protein family, only S100A11, S100A12 and S100A13 interact with the soluble form of TNF (sTNF) in vitro. The lowest equilibrium dissociation constants (K_d) for the complexes with monomeric sTNF determined using surface plasmon resonance spectroscopy range from 2 nM to 28 nM. The apparent K_d values for the complexes of multimeric sTNF with S100A11/A12 estimated from fluorimetric titrations are 0.1-0.3 µM. S100A12/A13 suppress the cytotoxic activity of sTNF against Huh-7 cells, as evidenced by the MTT assay. Structural modeling indicates that the sTNF-S100 interactions may interfere with the sTNF recognition by the therapeutic anti-TNFs. Bioinformatics analysis reveals dysregulation of TNF and S100A11/A12/A13 in numerous disorders. Overall, we have shown a novel potential regulatory role of the extracellular forms of specific S100 proteins that may affect the efficacy of anti-TNF treatment in various diseases.

An artificial neural network classification method employing longitudinally monitored immune biomarkers to predict the clinical outcome of critically ill COVID-19 patients

Background

The severe form of COVID-19 can cause a dysregulated host immune syndrome that might lead patients to death. To understand the underlying immune mechanisms that contribute to COVID-19 disease we have examined 28 different biomarkers in two cohorts of COVID-19 patients, aiming to systematically capture, quantify, and algorithmize how immune signals might be associated to the clinical outcome of COVID-19 patients.

Methods

The longitudinal concentration of 28 biomarkers of 95 COVID-19 patients was measured. We performed a dimensionality reduction analysis to determine meaningful biomarkers for explaining the data variability. The biomarkers were used as input of artificial neural network, random forest, classification and regression trees, k-nearest neighbors and support vector machines. Two different clinical cohorts were used to grant validity to the findings.

Results

We benchmarked the classification capacity of two COVID-19 clinicals studies with different models and found that artificial neural networks was the best classifier. From it, we could employ different sets of biomarkers to predict the clinical outcome of COVID-19 patients. First, all the biomarkers available yielded a satisfactory classification. Next, we assessed the prediction capacity of each protein separated. With a reduced set of biomarkers, our model presented 94% accuracy, 96.6% precision, 91.6% recall, and 95% of specificity upon the testing data. We used the same model to predict 83% and 87% (recovered and deceased) of unseen data, granting validity to the results obtained.

Conclusions

In this work, using state-of-the-art computational techniques, we systematically identified an optimal set of biomarkers that are related to a prediction capacity of COVID-19 patients. The screening of such biomarkers might assist in understanding the underlying immune response towards inflammatory diseases.

Mid-childhood fat mass and airflow limitation at 15 years: The mediating role of insulin resistance and C-reactive protein

BACKGROUND

We previously reported an association of high fat mass levels from age 9 to 15 years with lower forced expiratory flow in 1 s (FEV₁ )/forced vital capacity (FVC) ratio (i.e., increased risk of airflow limitation) at 15 years. Here, we aimed to assess whether insulin resistance and C-reactive protein (CRP) at 15 years partially mediate this association.

METHODS

We included 2263 children from the UK Avon Longitudinal Study of Parents and Children population-based cohort (ALSPAC). Four fat mass index (FMI) trajectories ("low," "medium-low," "medium-high," "high") from 9 to 15 years were previously identified using Group-Based Trajectory Modeling. Data on CRP, glucose, insulin, and post-bronchodilator FEV₁ /FVC were available at 15 years. We defined insulin resistance by the homeostasis model assessment-estimated insulin resistance index (HOMA-IR). We used adjusted linear regression models and a causal mediation analysis to assess the mediating role of HOMA-IR and CRP.

RESULTS

Compared to children in the "low" FMI trajectory, children in the "medium-high" and "high" FMI trajectories had lower FEV₁ /FVC at 15 years. The percentage of the total effect explained by HOMA-IR was 19.8% [-114.1 to 170.0] and 20.4% [1.6 to 69.0] for the "medium-high" and "high" trajectories, respectively. In contrast, there was little evidence for a mediating role of CRP.

CONCLUSION

The association between mid-childhood fat mass and FEV₁ /FVC ratio at 15 years may be partially mediated by insulin resistance.

Lung injury following cardiopulmonary bypass: a clinical update

INTRODUCTION

Cardiopulmonary bypass (CPB) is an integral component of cardiac surgery; however, one of its most critical complications is acute lung injury induced by multiple factors including systemic inflammatory response.

AREAS COVERED

The objective of this review is to investigate the multiple factors that can lead to CPB-induced lung injury. These include contact of blood components with the artificial surface of the CPB circuit, local and systemic inflammatory response syndrome (SIRS), lung ischemia/re-perfusion injury, arrest of ventilation, and circulating endotoxins. We also focus on possible interventions to curtail the negative impact of CPB, such as off-pump surgery, impregnation of the circuit with less biologically active substances, leukocyte depletion filters and ultrafiltration, and pharmacological agents such as steroids and aprotinin.

EXPERT OPINION

Although many aspects of CPB are proposed to contribute to lung injury, its overall role is still not clear. Multiple interventions have been introduced to reduce the risk of pulmonary dysfunction, with many of these interventions having shown promising results, significantly attenuating inflammatory mediators and improving post-operative outcome. However, since lung injury is multifactorial and affected by inextricably linked components, multiple interventions tackling each of them is required.

Pharmacologic therapies of ARDS: From natural herb to nanomedicine

Acute respiratory distress syndrome (ARDS) is a common critical illness in respiratory care units with a huge public health burden. Despite tremendous advances in the prevention and treatment of ARDS, it remains the main cause of intensive care unit (ICU) management, and the mortality rate of ARDS remains unacceptably high. The poor performance of ARDS is closely related to its heterogeneous clinical syndrome caused by complicated pathophysiology. Based on the different pathophysiology phases, drugs, protective mechanical ventilation, conservative fluid therapy, and other treatment have been developed to serve as the ARDS therapeutic methods. In recent years, there has been a rapid development in nanomedicine, in which nanoparticles as drug delivery vehicles have been extensively studied in the treatment of ARDS. This study provides an overview of pharmacologic therapies for ARDS, including conventional drugs, natural medicine therapy, and nanomedicine. Particularly, we discuss the unique mechanism and strength of nanomedicine which may provide great promises in treating ARDS in the future.

Ferret acute lung injury model induced by repeated nebulized lipopolysaccharide administration

Inflammatory lung diseases affect millions of people worldwide. These diseases are caused by a number of factors such as pneumonia, sepsis, trauma, and inhalation of toxins. Pulmonary function testing (PFT) is a valuable functional methodology for better understanding mechanisms of lung disease, measuring disease progression, clinical diagnosis, and evaluating therapeutic interventions. Animal models of inflammatory lung diseases are needed that accurately recapitulate disease manifestations observed in human patients and provide an accurate prediction of clinical outcomes using clinically relevant pulmonary disease parameters. In this study, we evaluated a ferret lung inflammation model that closely represents multiple clinical manifestations of acute lung inflammation and injury observed in human patients. Lipopolysaccharide (LPS) from Pseudomonas aeruginosa was nebulized into ferrets for 7 repeated daily doses. Repeated exposure to nebulized LPS resulted in a restrictive pulmonary injury characterized using Buxco forced maneuver PFT system custom developed for ferrets. This is the first study to report repeated forced maneuver PFT in ferrets, establishing lung function measurements pre- and post-injury in live animals. Bronchoalveolar lavage and histological analysis confirmed that LPS exposure elicited pulmonary neutrophilic inflammation and structural damage to the alveoli. We believe this ferret model of lung inflammation, with clinically relevant disease manifestations and parameters for functional evaluation, is a useful pre-clinical model for understanding human inflammatory lung disease and for the evaluation of potential therapies.

Expression of Major Lipid Raft Protein Raftlin in Chronic Rhinosinusitis with Nasal Polyps in Smoking and Non-Smoking Patients Correlated with Interleukin-17 and Tumor Necrosis Factor-α Levels

Raftlin, as an inflammatory biomarker, has been previously reported in chronic inflammatory diseases. This study investigates the expression of Raftlin in cigarette smokers and in chronic rhinosinusitis with nasal polyps (CRSwNP), as well as evaluating its correlation with interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) levels. A total of 30 CRSwNP non-smoking and 16 CRSwNP + SK (smoking) patients undergoing endoscopic sinus surgery were enrolled, while 20 middle turbinate tissue pieces were examined and performed as the control group. In nasal mucosa epithelial staining, Raftlin levels were elevated in the columnar cells and were stained much more intensely in the CRSwNP and CRSwNP + SK groups. Raftlin was located more closely to the apical region of the epithelium in the CRSwNP + SK group; however, the Raftlin levels from whole nasal tissue pieces, according to ELISA data, showed that there was no significant difference between the three different study groups. A positive relationship by Pearson correlation was found between IL-17 or TNF-α levels and Raftlin levels. Taken together, these data indicate that increasing Raftlin expression in columnar cells might involve nasal epithelial remodeling in smokers with CRSwNP.

The effects of asthma on the oxidative stress, inflammation, and endothelial dysfunction in children with pneumonia

BACKGROUND

In community-acquired pneumonia (CAP), pulmonary vascular endothelial dysfunction, inflammation, and oxidative stress (OS) are prominent and interesting as the unfavorable clinical outcomes of it. Asthma as a common chronic respiratory disease may affect the clinical outcomes of pneumonia, but the exact mechanism of this effect remains unclear. The present study aimed to assess the effects of asthma on the OS, inflammation, and endothelial dysfunction biomarkers in the children pneumonia.

METHODS

A cross-sectional study designed with a total of 75 children including both severe CAP and asthma (as group I), severe CAP alone (as group II), and healthy children (as group III) was conducted. Fasting blood samples were taken to the assay of serum malondialdehyde (MDA), total antioxidant capacity (TAC), tumor necrosis factor-alpha (TNF-α), soluble vascular cell adhesion molecule-1 (sVCAM-1), and plasminogen activator inhibitor-1 (PAI-1). The mean of anthropometric and biochemical parameters was compared by ANOVA and Tukey post-hoc test between groups.

RESULTS

We observed TAC levels in groups I and II (0.997 ± 0.22 and 1.23 ± 0.21 mmol/l, respectively) were significantly lower compared with group III (1.46 ± 0.19 mmol/l, P value < 0.001). It was significantly higher in group II than in group I (P value < 0.001). Also, we observed MDA and TNF-α levels in groups I (6.94 ± 1.61 μmol/l, 7.34 ± 2.23 pg/ml, respectively) and II (2.57 ± 0.40 μmol/l, 5.54 ± 1.84 pg/ml, respectively) were significantly higher compared with group III (1.89 ± 0.27 μmol/l, 3.42 ± 1.32 pg/ml, P value < 0.001, P value < 0.001, respectively). VCAM-1 and PAI-1 levels as the endothelial dysfunction biomarkers were significantly higher in group I (1.5 ± 0.62 mmol/l, 10.52 ± 3.2 AU/ml, respectively) compared with groups II (1.06 ± 0.53 mmol/l and 8.23 ± 3.4 AU/ml; P value < 0.001, P value < 0.001, respectively) and III (0.6 ± 0.35 mmol/l and 2.39 ± 0.83 AU/ml; P value < 0.001, P value < 0.001, respectively). Also, VCAM-1 and PAI-1 levels were significantly higher in group II compared with groups III (P value < 0.001, P value < 0.001).

CONCLUSIONS

Asthma can exacerbate the vascular dysfunction of pneumonia in children by increasing oxidative stress, inflammation, and endothelial dysfunction.

Phenotypic and Transcriptional Changes of Pulmonary Immune Responses in Dogs Following Canine Distemper Virus Infection

Canine distemper virus (CDV), a morbillivirus within the family Paramyxoviridae, is a highly contagious infectious agent causing a multisystemic, devastating disease in a broad range of host species, characterized by severe immunosuppression, encephalitis and pneumonia. The present study aimed at investigating pulmonary immune responses of CDV-infected dogs in situ using immunohistochemistry and whole transcriptome analyses by bulk RNA sequencing. Spatiotemporal analysis of phenotypic changes revealed pulmonary immune responses primarily driven by MHC-II⁺, Iba-1⁺ and CD204⁺ innate immune cells during acute and subacute infection phases, which paralleled pathologic lesion development and coincided with high viral loads in CDV-infected lungs. CD20⁺ B cell numbers initially declined, followed by lymphoid repopulation in the advanced disease phase. Transcriptome analysis demonstrated an increased expression of transcripts related to innate immunity, antiviral defense mechanisms, type I interferon responses and regulation of cell death in the lung of CDV-infected dogs. Molecular analyses also revealed disturbed cytokine responses with a pro-inflammatory M1 macrophage polarization and impaired mucociliary defense in CDV-infected lungs. The exploratory study provides detailed data on CDV-related pulmonary immune responses, expanding the list of immunologic parameters potentially leading to viral elimination and virus-induced pulmonary immunopathology in canine distemper.

Inflammatory Biomarkers in Exhaled Breath Condensate: A Systematic Review

Inflammation is a comprehensive set of physiological processes that an organism undertakes in response to a wide variety of foreign stimuli, such as viruses, bacteria, and inorganic particles. A key role is played by cytokines, protein-based chemical mediators produced by a broad range of cells, including the immune cells recruited in the inflammation site. The aim of this systematic review is to compare baseline values of pro/anti-inflammatory biomarkers measured in Exhaled Breath Condensate (EBC) in healthy, non-smoking adults to provide a summary of the concentrations reported in the literature. We focused on: interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-α), and C reactive protein (CRP). Eligible articles were identified in PubMed, Embase, and Cochrane CENTRAL. Due to the wide differences in methodologies employed in the included articles concerning EBC sampling, storage, and analyses, research protocols were assessed specifically to test their adherence to the ATS/ERS Task Force guidelines on EBC. The development of reference intervals for these biomarkers can result in their introduction and use in both research and clinical settings, not only for monitoring purposes but also, in the perspective of future longitudinal studies, as predictive parameters for the onset and development of chronic diseases with inflammatory aetiology.

Caveolin-1 identified as a key mediator of acute lung injury using bioinformatics and functional research

Acute lung injury (ALI) is a potentially life-threatening, devastating disease with an extremely high rate of mortality. The underlying mechanism of ALI is currently unclear. In this study, we aimed to confirm the hub genes associated with ALI and explore their functions and molecular mechanisms using bioinformatics methods. Five microarray datasets available in GEO were used to perform Robust Rank Aggregation (RRA) to identify differentially expressed genes (DEGs) and the key genes were identified via the protein-protein interaction (PPI) network. Lipopolysaccharide intraperitoneal injection was administered to establish an ALI model. Overall, 40 robust DEGs, which are mainly involved in the inflammatory response, protein catabolic process, and NF-κB signaling pathway were identified. Among these DEGs, we identified two genes associated with ALI, of which the CAV-1/NF-κB axis was significantly upregulated in ALI, and was identified as one of the most effective targets for ALI prevention. Subsequently, the expression of CAV-1 was knocked down using AAV-shCAV-1 or CAV-1-siRNA to study its effect on the pathogenesis of ALI in vivo and in vitro. The results of this study indicated that CAV-1/NF-κB axis levels were elevated in vivo and in vitro, accompanied by an increase in lung inflammation and autophagy. The knockdown of CAV-1 may improve ALI. Mechanistically, inflammation was reduced mainly by decreasing the expression levels of CD3 and F4/80, and activating autophagy by inhibiting AKT/mTOR and promoting the AMPK signaling pathway. Taken together, this study provides crucial evidence that CAV-1 knockdown inhibits the occurrence of ALI, suggesting that the CAV-1/NF-κB axis may be a promising therapeutic target for ALI treatment.

The exogenous surfactant pre-treatment attenuates ventilator-induced lung injury in adult rats

Mechanical ventilation is an essential supportive therapy in the treatment of critical patients, and it aims to maintain adequate gas exchange; however, it can also contribute to inflammation and oxidative stress, thus leading to lung injury. We tested the hypothesis that exogenous surfactant administration will be protective against ventilator-induced lung injury in adult healthy Wistar rats both because of its anti-inflammatory properties as well as its role in preventing alveolar collapse at end-expiration. Thus, the effect of intranasal instillation of a bovine exogenous surfactant was tested in Wistar rats submitted to mechanical ventilation. The animals were divided into four groups: (1) CONTROL; (2) SURFACTANT; (3) Mechanical ventilation (MV); (4) MV with pre-treatment with surfactant (MVSURFACTANT). The MV and MVSURFACTANT were submitted to MV with high tidal volume (12 mL/kg) for 1 h. After the experimental protocol, all animals were euthanized and the arterial blood, bronchoalveolar lavage fluid and lungs were collected for biochemical, immunoenzymatic assay, arterial blood gases, and morphometric analyzes. The Wistar rats that received exogenous surfactant (Survanta®) by intranasal instillation before MV demonstrated reduced levels of leukocytes, inflammatory biomarkers such as CCL2, IL-1, IL-6 and TNF-α. Furthermore, it prevented oxidative damage by reducing lipid peroxidation and protein carbonylation as well as histological pattern changes of pulmonary parenchyma. Our data indicate that exogenous surfactant attenuated lung inflammation and redox imbalance induced by mechanical ventilation in healthy adult rats suggesting a preventive effect on ventilator-induced lung injury.

Comprehensive overview of COVID-19-related respiratory failure: focus on cellular interactions

The pandemic outbreak of coronavirus disease 2019 (COVID-19) has created health challenges in all parts of the world. Understanding the entry mechanism of this virus into host cells is essential for effective treatment of COVID-19 disease. This virus can bind to various cell surface molecules or receptors, such as angiotensin-converting enzyme 2 (ACE2), to gain cell entry. Respiratory failure and pulmonary edema are the most important causes of mortality from COVID-19 infections. Cytokines, especially proinflammatory cytokines, are the main mediators of these complications. For normal respiratory function, a healthy air-blood barrier and sufficient blood flow to the lungs are required. In this review, we first discuss airway epithelial cells, airway stem cells, and the expression of COVID-19 receptors in the airway epithelium. Then, we discuss the suggested molecular mechanisms of endothelial dysfunction and blood vessel damage in COVID-19. Coagulopathy can be caused by platelet activation leading to clots, which restrict blood flow to the lungs and lead to respiratory failure. Finally, we present an overview of the effects of immune and non-immune cells and cytokines in COVID-19-related respiratory failure.

Human surfactant protein D facilitates SARS-CoV-2 pseudotype binding and entry in DC-SIGN expressing cells, and downregulates spike protein induced inflammation

Lung surfactant protein D (SP-D) and Dendritic cell-specific intercellular adhesion molecules-3 grabbing non-integrin (DC-SIGN) are pathogen recognising C-type lectin receptors. SP-D has a crucial immune function in detecting and clearing pulmonary pathogens; DC-SIGN is involved in facilitating dendritic cell interaction with naïve T cells to mount an anti-viral immune response. SP-D and DC-SIGN have been shown to interact with various viruses, including SARS-CoV-2, an enveloped RNA virus that causes COVID-19. A recombinant fragment of human SP-D (rfhSP-D) comprising of α-helical neck region, carbohydrate recognition domain, and eight N-terminal Gly-X-Y repeats has been shown to bind SARS-CoV-2 Spike protein and inhibit SARS-CoV-2 replication by preventing viral entry in Vero cells and HEK293T cells expressing ACE2. DC-SIGN has also been shown to act as a cell surface receptor for SARS-CoV-2 independent of ACE2. Since rfhSP-D is known to interact with SARS-CoV-2 Spike protein and DC-SIGN, this study was aimed at investigating the potential of rfhSP-D in modulating SARS-CoV-2 infection. Coincubation of rfhSP-D with Spike protein improved the Spike Protein: DC-SIGN interaction. Molecular dynamic studies revealed that rfhSP-D stabilised the interaction between DC-SIGN and Spike protein. Cell binding analysis with DC-SIGN expressing HEK 293T and THP- 1 cells and rfhSP-D treated SARS-CoV-2 Spike pseudotypes confirmed the increased binding. Furthermore, infection assays using the pseudotypes revealed their increased uptake by DC-SIGN expressing cells. The immunomodulatory effect of rfhSP-D on the DC-SIGN: Spike protein interaction on DC-SIGN expressing epithelial and macrophage-like cell lines was also assessed by measuring the mRNA expression of cytokines and chemokines. RT-qPCR analysis showed that rfhSP-D treatment downregulated the mRNA expression levels of pro-inflammatory cytokines and chemokines such as TNF-α, IFN-α, IL-1β, IL- 6, IL-8, and RANTES (as well as NF-κB) in DC-SIGN expressing cells challenged by Spike protein. Furthermore, rfhSP-D treatment was found to downregulate the mRNA levels of MHC class II in DC expressing THP-1 when compared to the untreated controls. We conclude that rfhSP-D helps stabilise the interaction between SARS- CoV-2 Spike protein and DC-SIGN and increases viral uptake by macrophages via DC-SIGN, suggesting an additional role for rfhSP-D in SARS-CoV-2 infection.

Identifying Active Compounds and Mechanisms of Citrus changshan-Huyou Y. B. Chang against URTIs-Associated Inflammation by Network Pharmacology in Combination with Molecular Docking

Purpose. The ripe fruits of Citrus changshan-huyou, known as Quzhou Fructus Aurantii (QFA), have been commonly used for respiratory diseases. The purpose of this study was to investigate their active compounds and demonstrate their mechanism in the treatment of upper respiratory tract infections (URTIs) through network pharmacology and molecular docking. Methods. The prominent compounds of QFA were acquired from TCMSP database. Their targets were retrieved from SwissTargetPrediction database, and target genes associated with URTIs were collected from DisGeNET and GeneCards databases. The target protein-protein interaction (PPI) network was constructed by using STRING database and Cytoscape. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were enriched. Visual compound-target-pathway network was established with Cytoscape. The effects of compounds were verified on the inhibitory activities against phosphoinositide 3-kinases (PI3Ks). Finally, the molecular docking was carried out to confirm the binding affinity of the bioactive compounds and target proteins. Results. Five important active compounds, naringenin (NAR), tangeretin (TAN), luteolin (LUT), hesperetin (HES), and auraptene (AUR), were obtained. The enrichment analysis demonstrated that the pathways associated with inflammation mainly contained PI3K/Akt signalling pathway, TNF signalling pathway, and so on. The most important targets covering inflammation-related proteins might be PI3Ks. In vitro assays and molecular docking exhibited that TAN, LUT, and AUR acted as PI3Kγ inhibitors. Conclusion. The results revealed that QFA could treat URTIs through a multi-compound, multi-target, multi-pathway network, in which TAN, LUT, and AUR acted as PI3Kγ inhibitors, probably contributing to a crucial role in treatment of URTIs.

Increased Abundance of Achromobacter xylosoxidans and Bacillus cereus in Upper Airway Transcriptionally Active Microbiome of COVID-19 Mortality Patients Indicates Role of Co-Infections in Disease Severity and Outcome

The modulators of severe COVID-19 have emerged as the most intriguing features of SARS-CoV-2 pathogenesis. This is especially true as we are encountering variants of concern (VOC) with increased transmissibility and vaccination breakthroughs. Microbial co-infections are being investigated as one of the crucial factors for exacerbation of disease severity and complications of COVID-19. A key question remains whether early transcriptionally active microbial signature/s in COVID-19 patients can provide a window for future disease severity susceptibility and outcome? Using complementary metagenomics sequencing approaches, respiratory virus oligo panel (RVOP) and Holo-seq, our study highlights the possible functional role of nasopharyngeal early resident transcriptionally active microbes in modulating disease severity, within recovered patients with sub-phenotypes (mild, moderate, severe) and mortality. The integrative analysis combines patients' clinical parameters, SARS-CoV-2 phylogenetic analysis, microbial differential composition, and their functional role. The clinical sub-phenotypes analysis led to the identification of transcriptionally active bacterial species associated with disease severity. We found significant transcript abundance of Achromobacter xylosoxidans and Bacillus cereus in the mortality, Leptotrichia buccalis in the severe, Veillonella parvula in the moderate, and Actinomyces meyeri and Halomonas sp. in the mild COVID-19 patients. Additionally, the metabolic pathways, distinguishing the microbial functional signatures between the clinical sub-phenotypes, were also identified. We report a plausible mechanism wherein the increased transcriptionally active bacterial isolates might contribute to enhanced inflammatory response and co-infections that could modulate the disease severity in these groups. Current study provides an opportunity for potentially using these bacterial species for screening and identifying COVID-19 patient sub-groups with severe disease outcome and priority medical care. IMPORTANCE COVID-19 is invariably a disease of diverse clinical manifestation, with multiple facets involved in modulating the progression and outcome. In this regard, we investigated the role of transcriptionally active microbial co-infections as possible modulators of disease pathology in hospital admitted SARS-CoV-2 infected patients. Specifically, can there be early nasopharyngeal microbial signatures indicative of prospective disease severity? Based on disease severity symptoms, the patients were segregated into clinical sub-phenotypes: mild, moderate, severe (recovered), and mortality. We identified significant presence of transcriptionally active isolates, Achromobacter xylosoxidans and Bacillus cereus in the mortality patients. Importantly, the bacterial species might contribute toward enhancing the inflammatory responses as well as reported to be resistant to common antibiotic therapy, which together hold potential to alter the disease severity and outcome.

Lung Inflammation Is Associated with Preeclampsia Development in the Rat

Preeclampsia (PE) is an obstetric complication associated with significant health implications for the fetus and mother. Studies have shown a correlation between lung disease development and PE. Gas6 protein is expressed in the lung and placenta, and binds to the AXL Tyrosine kinase receptor. Recently, our laboratory utilized Gas6 to induce preeclamptic-like conditions in rats. Our objective was to determine the role of Gas6/AXL signaling in the maternal lung during PE development. Briefly, pregnant rats were divided into control, Gas6, or Gas6 + R428 (an AXL inhibitor). Immunofluorescence was performed to determine AXL expression. Bronchoalveolar lavage fluid (BALF) was procured for the assessment of inflammatory cell secretion. Western blot was performed to detect signaling molecules and ELISA determined inflammatory cytokines. We observed increased proteinuria and increased blood pressure in Gas6-treated animals. AXL was increased in the lungs of the treated animals and BALF fluid revealed elevated total protein abundance in Gas6 animals. Extracellular-signal regulated kinase (ERK) and protein kinase B (AKT) signaling in the lung appeared to be mediated by Gas6 as well as the secretion of inflammatory cytokines. We conclude that Gas6 signaling is capable of inducing PE and that this is associated with increased lung inflammation.

Lung-adapted Staphylococcus aureus isolates with dysfunctional agr system trigger a proinflammatory response

BACKGROUND

Staphylococcus aureus (Sa) dominates the lung microbiota of Cystic Fibrosis (CF) children and persistent clones are able to establish chronic infection for years, having a direct deleterious impact on lung function. However, in this context, the exact contribution of Sa to the decline in respiratory function in CF children is not elucidated.

METHODS

To investigate the contribution of persistent S. aureus clones in CF disease, we undertook the analysis of sequential isogenic isolates recovered from 15 young CF patients.

RESULTS

Using an Air-Liquid infection model, we observed a strong correlation between Sa adaption in the lung (late isolates), low toxicity and pro-inflammatory cytokine secretion. Conversely, early isolates appeared to be highly cytotoxic but did not promote cytokine secretion. We found that cytokine secretion was dependent on Staphylococcal protein A (Spa), which was selectively expressed in late compared to early isolates as a consequence of dysfunctional agr quorum-sensing system. Finally, we demonstrated the involvement of TNF-α receptor 1 signaling in the inflammatory response of airway epithelial cells to these lung-adapted Sa isolates.

CONCLUSION

Our results suggest an unexpected direct role of bacterial lung adaptation in the progression of chronic lung disease by promoting a pro-inflammatory response through acquired agr dysfunction.

Verapamil attenuates oxidative stress and inflammatory responses in cigarette smoke (CS)-induced murine models of acute lung injury and CSE-stimulated RAW 264.7 macrophages via inhibiting the NF-κB pathway

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), severe form of ALI, are characterized by overwhelming of lung inflammation, and no treatment is currently available to treat ALI/ARDS. Cigarette smoke (CS) is one of the prime causes to induce ALI/ARDS via oxidative stress. Despite extensive research, no appropriate therapy is currently available to treat ALI/ARDS. Hence, new potential approaches are needed to treat ALI/ARDS. Consequently, this project was designed to explore the protective effects of verapamil against CS-induced ALI by in vivo and in vitro method. In vivo data obtained from respiratory mechanics, pulmonary morphometric analyses and lung histopathology revealed that verapamil dose-dependently and strikingly decreased the lung weight coefficient, attenuated the albumin exudation into lungs, minimized the infiltration of macrophages and neutrophils into lungs, reduced the pro-inflammatory cytokines (tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and keratinocyte chemoattractant (KC)) production, and improved the hypoxemia and lung histopathological changes. Similarly, verapamil also reduced the production of TNF-α, IL-6 and KC from cigarette smoke extract (CSE)-stimulated RAW 264.7 macrophage. Importantly, verapamil dose-dependently and remarkably suppressed the CS-induced oxidative stress via not only reducing the myeloperoxidase (MPO) activity of lungs, total oxidative stress (TOS) and malondialdehyde (MDA) content in the lungs and supernatant of RAW 264.7 macrophage but also improving total antioxidant capacity (TAC) and superoxide dismutase (SOD) production. Finally, verapamil strikingly decreased the NF-κB expression both in in vivo and in vitro models. Hence, verapamil has positive therapeutic effects against CS-induced ALI via suppressing uncontrolled inflammatory response, oxidative stress and NF-κB p65 signaling.

Isoflurane attenuates sepsis-associated lung injury

Acute lung injury is one of major complications associated with sepsis, responsible for morbidity and mortality. Patients who suffer from acute lung injury often require respiratory support under sedations, and it would be important to know the role of sedatives in lung injury. We examined volatile anesthetic isoflurane, which is commonly used in surgical setting, but also used as an alternative sedative in intensive care settings in European countries and Canada. We found that isoflurane exposure attenuated neutrophil recruitment to the lungs in mice suffering from experimental polymicrobial abdominal sepsis. We found that isoflurane attenuated one of major neutrophil chemoattractants LTB4 mediated response via its receptor BLT1 in neutrophils. Furthermore, we have shown that isoflurane directly bound to BLT1 by a competition assay using newly developed labeled BLT1 antagonist, suggesting that isoflurane would be a BLT1 antagonist.

Evaluation of a Novel Adjuvanted Vaccine for Ultrashort Regimen Therapy of Artemisia Pollen-Induced Allergic Bronchial Asthma in a Mouse Model

Wormwood (Artemisia) pollen is among the top 10 aeroallergens globally that cause allergic rhinitis and bronchial asthma. Allergen-specific immunotherapy (ASIT) is the gold standard for treating patients with allergic rhinitis, conjunctivitis, and asthma. A significant disadvantage of today's ASIT methods is the long duration of therapy and multiplicity of allergen administrations. The goal of this study was to undertake a pilot study in mice of a novel ultrashort vaccine immunotherapy regimen incorporating various adjuvants to assess its ability to treat allergic bronchial asthma caused by wormwood pollen. We evaluated in a mouse model of wormwood pollen allergy candidates comprising recombinant Art v 1 wormwood pollen protein formulated with either newer (Advax, Advax-CpG, ISA-51) or more traditional [aluminum hydroxide, squalene water emulsion (SWE)] adjuvants administered by the intramuscular or subcutaneous route vs. intranasal administration of a mucosal vaccine formulation using chitosan-mannose nanoparticle entrapped with Art v 1 protein. The vaccine formulations were administered to previously wormwood pollen-sensitized animals, four times at weekly intervals. Desensitization was determined by measuring decreases in immunoglobulin E (IgE), cellular immunity, ear swelling test, and pathological changes in the lungs of animals after aeroallergen challenge. Art v 1 protein formulation with Advax, Advax-CpG, SWE, or ISA-51 adjuvants induced a significant decrease in both total and Art v 1-specific IgE with a concurrent increase in Art v 1-specific IgG compared to the positive control group. There was a shift in T-cell cytokine secretion toward a Th1 (Advax-CpG, ISA-51, and Advax) or a balanced Th1/Th2 (SWE) pattern. Protection against lung inflammatory reaction after challenge was seen with ISA-51, Advax, and SWE Art v 1 formulations. Overall, the ISA-51-adjuvanted vaccine group induced the largest reduction of allergic ear swelling and protection against type 2 and non-type 2 lung inflammation in challenged animals. This pilot study shows the potential to develop an ultrashort ASIT regimen for wormwood pollen-induced bronchial asthma using appropriately adjuvanted recombinant Art v 1 protein. The data support further preclinical studies with the ultimate goal of advancing this therapy to human clinical trials.

Innate but Not Adaptive Immunity Regulates Lung Recovery from Chronic Exposure to Graphene Oxide Nanosheets

Graphene has drawn a lot of interest in the material community due to unique physicochemical properties. Owing to a high surface area to volume ratio and free oxygen groups, the oxidized derivative, graphene oxide (GO) has promising potential as a drug delivery system. Here, the lung tolerability of two distinct GO varying in lateral dimensions is investigated, to reveal the most suitable candidate platform for pulmonary drug delivery. Following repeated chronic pulmonary exposure of mice to GO sheet suspensions, the innate and adaptive immune responses are studied. An acute and transient influx of neutrophils and eosinophils in the alveolar space, together with the replacement of alveolar macrophages by interstitial ones and a significant activation toward anti-inflammatory subsets, are found for both GO materials. Micrometric GO give rise to persistent multinucleated macrophages and granulomas. However, neither adaptive immune response nor lung tissue remodeling are induced after exposure to micrometric GO. Concurrently, milder effects and faster tissue recovery, both associated to a faster clearance from the respiratory tract, are found for nanometric GO, suggesting a greater lung tolerability. Taken together, these results highlight the importance of dimensions in the design of biocompatible 2D materials for pulmonary drug delivery system.

Amelioration of Ovalbumin-Induced Allergic Asthma by Juglans regia via Downregulation of Inflammatory Cytokines and Upregulation of Aquaporin-1 and Aquaporin-5 in Mice

Juglans regia (J. regia) has been used traditionally to treat cough and asthma. The present study evaluates the immunomodulatory and anti-inflammatory potential of J. regia against ovalbumin (OVA)-induced allergic asthma. Intraperitoneal sensitization proceeded by intranasal challenge with OVA was used to induce allergic asthma. BALB/c mice were treated with methanol, n-hexane, and ethyl acetate extracts of J. regia and methylprednisolone one week after 2^nd sensitization with OVA and continued for 7 days. mRNA expression levels of IL-4, IL-5, IL-13, AQP-1, AQP-5 TNF-α, TGF-β, and NF-kB were determined using reverse transcription polymerase chain reaction. Hematoxylin and eosin, and periodic acidic-Schiff stains were used for histopathological studies of lung tissues. The data presented all three extracts of J. regia significantly ameliorated airway inflammation by reducing expression levels of IL-4, IL-5, and IL-13 and TNF-α in OVA-treated mice. The suppression of goblet cells hyperplasia and inflammatory cells infiltration by J. regia involved low TGF-β and NF-kB levels. Pretreatment with J. regia also increased the AQP-1 and AQP-5 expression levels in mice treated with OVA. This study supported the traditional use of J. regia and proposed that J. regia ameliorated allergic asthma by suppression of proinflammatory cytokines and elevation of AQP-1 and AQP-5 expression levels.

Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance

Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.

Integrated Network Pharmacology and Experimental Validation Approach to Investigate the Therapeutic Effects of Capsaicin on Lipopolysaccharide-Induced Acute Lung Injury

An integrated method combining network pharmacology and in vivo experiment was performed to investigate the therapeutic mechanism of capsaicin (Cap) against acute lung injury. The potential key genes and signaling pathways involved in the therapeutic effect of Cap were predicted by the network pharmacology analyses. Additionally, the histological assessment, ELISA, and RT-qPCR were performed to confirm the therapeutic effect and the potential mechanism action involved. Our findings showed that TNF, IL-6, CXCL1, CXCL2, and CXCL10 were part of the top 50 genes. Enrichment analysis revealed that those potential genes were enriched in the TNF signaling pathway and IL-17 signaling pathway. In vivo experiment results showed that Cap alleviated histopathological changes, decreased inflammatory infiltrated cells and inflammatory cytokines, and improved antioxidative enzyme activities in the bronchoalveolar lavage fluid (BALF). Furthermore, Cap treatment effectively downregulated TNF, IL-6, NF-κB, CXCL1, CXCL2, and CXCL10 in lung tissue. Thus, our findings demonstrated that Cap has the therapeutic effect on LPS-induced acute lung injury in neonatal rats via suppression of the TNF signaling pathway and IL-17 signaling pathway.

Blocking TNF signaling may save lives in COVID-19 infection

Global vaccination effort and better understanding of treatment strategies provided a ray of hope for improvement in COVID-19 pandemic, however, in many countries, the disease continues to collect its death toll. The major pathogenic mechanism behind severe cases associated with high mortality is the burst of pro-inflammatory cytokines TNF, IL-6, IFNγ and others, resulting in multiple organ failure. Although the exact contribution of each cytokine is not clear, we provide an evidence that the central mediator of cytokine storm and its devastating consequences may be TNF. This cytokine is known to be involved in activated blood clotting, lung damage, insulin resistance, heart failure, and other conditions. A number of currently available pharmaceutical agents such as monoclonal antibodies and soluble TNF receptors can effectively prevent TNF from binding to its receptor(s). Other drugs are known to block NFkB, the major signal transducer molecule used in TNF signaling, or to block kinases involved in downstream activation cascades. Some of these medicines have already been selected for clinical trials, but more work is needed. A simple, rapid, and inexpensive method of directly monitoring TNF levels may be a valuable tool for a timely selection of COVID-19 patients for anti-TNF therapy.

Optimization of long-term cold storage of rat precision-cut lung slices with a tissue preservation solution

Precision-cut lung slices (PCLS) are used as ex vivo model of the lung to fill the gap between in vitro and in vivo experiments. To allow optimal utilization of PCLS, possibilities to prolong slice viability via cold storage using optimized storage solutions were evaluated. Rat PCLS were cold stored in DMEM/F-12 or two different preservation solutions for up to 28 days at 4°C. After rewarming in DMEM/F-12, metabolic activity, live/dead staining, and mitochondrial membrane potential was assessed to analyze overall tissue viability. Single-cell suspensions were prepared and proportions of CD45⁺, EpCAM⁺, CD31⁺, and CD90⁺ cells were analyzed. As functional parameters, TNF-α expression was analyzed to detect inflammatory activity and bronchoconstriction was evaluated after acetylcholine stimulus. After 14 days of cold storage, viability and mitochondrial membrane potential were significantly better preserved after storage in solution 1 (potassium chloride rich) and solution 2 (potassium- and lactobionate-rich analog) compared with DMEM/F-12. Analysis of cell populations revealed efficient preservation of EpCAM⁺, CD31⁺, and CD90⁺ cells. Proportion of CD45⁺ cells decreased during cold storage but was better preserved by both modified solutions than by DMEM/F-12. PCLS stored in solution 1 responded substantially longer to inflammatory stimulation than those stored in DMEM/F-12 or solution 2. Analysis of bronchoconstriction revealed total loss of function after 14 days of storage in DMEM/F-12 but, in contrast, a good response in PCLS stored in the optimized solutions. An improved base solution with a high potassium chloride concentration optimizes cold storage of PCLS and allows shipment between laboratories and stockpiling of tissue samples.

Attomolar analyte sensing techniques (AttoSens): a review on a decade of progress on chemical and biosensing nanoplatforms

Detecting the ultra-low abundance of analytes in real-life samples, such as biological fluids, water, soil, and food, requires the design and development of high-performance biosensing modalities. The breakthrough efforts from the scientific community have led to the realization of sensing technologies that measure the analyte's ultra-trace level, with relevant sensitivity, selectivity, response time, and sampling efficiency, referred to as Attomolar Analyte Sensing Techniques (AttoSens) in this review. In an AttoSens platform, 1 aM detection corresponds to the quantification of 60 target analyte molecules in 100 μL of sample volume. Herein, we review the approaches listed for various sensor probe design, and their sensing strategies that paved the way for the detection of attomolar (aM: 10^-18 M) concentration of analytes. A summary of the technological advances made by the diverse AttoSens trends from the past decade is presented.

Targeting Molecular Inflammatory Pathways in Granuloma as Host-Directed Therapies for Tuberculosis

Globally, more than 10 million people developed active tuberculosis (TB), with 1.4 million deaths in 2020. In addition, the emergence of drug-resistant strains in many regions of the world threatens national TB control programs. This requires an understanding of host-pathogen interactions and finding novel treatments including host-directed therapies (HDTs) is of utter importance to tackle the TB epidemic. Mycobacterium tuberculosis (Mtb), the causative agent for TB, mainly infects the lungs causing inflammatory processes leading to immune activation and the development and formation of granulomas. During TB disease progression, the mononuclear inflammatory cell infiltrates which form the central structure of granulomas undergo cellular changes to form epithelioid cells, multinucleated giant cells and foamy macrophages. Granulomas further contain neutrophils, NK cells, dendritic cells and an outer layer composed of T and B lymphocytes and fibroblasts. This complex granulomatous host response can be modulated by Mtb to induce pathological changes damaging host lung tissues ultimately benefiting the persistence and survival of Mtb within host macrophages. The development of cavities is likely to enhance inter-host transmission and caseum could facilitate the dissemination of Mtb to other organs inducing disease progression. This review explores host targets and molecular pathways in the inflammatory granuloma host immune response that may be beneficial as target candidates for HDTs against TB.

Anti-Gastritis and Anti-Lung Injury Effects of Pine Tree Ethanol Extract Targeting Both NF-κB and AP-1 Pathways

An ethanol extract (Pd-EE) of Pinus densiflora Siebold and Zucc was derived from the branches of pine trees. According to the Donguibogam, pine resin has the effects of lowering the fever, reducing pain, and killing worms. The purpose of this study is to investigate whether Pd-EE has anti-inflammatory effects. During in vitro trials, NO production, as well as changes in the mRNA levels of inflammation-related genes and the phosphorylation levels of related proteins, were confirmed in RAW264.7 cells activated with lipopolysaccharide depending on the presence or absence of Pd-EE treatment. The activities of transcription factors were checked in HEK293T cells transfected with adapter molecules in the inflammatory pathway. The anti-inflammatory efficacy of Pd-EE was also estimated in vivo with acute gastritis and acute lung injury models. LC-MS analysis was conducted to identify the components of Pd-EE. This extract reduced the production of NO and the mRNA expression levels of iNOS, COX-2, and IL-6 in RAW264.7 cells. In addition, protein expression levels of p50 and p65 and phosphorylation levels of FRA1 were decreased. In the luciferase assay, the activities of NF-κB and AP-1 were lowered. In acute gastritis and acute lung injury models, Pd-EE suppressed inflammation, resulting in alleviated damage.

Chaiqin Qingning Capsule Inhibits Influenza Virus Infection and Inflammation In Vitro and In Vivo

Background

Chaiqin Qingning Capsule (CQ-C) is a traditional Chinese medicine (TCM) formula commonly used to treat respiratory infectious diseases in China. The aim of this study was to detect the effect and mechanism of CQ-C treated with influenza virus in vitro and vivo.

Methods

The cytotoxicity and antiviral activity of CQ-C in vitro was determined by methyl thiazolyl tetrazolium (MTT) assay. The regulation of CQ-C on cytokine/chemokine expression was evaluated using RT-qPCR. In addition, the effect of CQ-C on the pathway protein, NF-κB, and its phosphorylation level was verified by western blotting. After virus inoculation, BALB/c mice were administered with CQ-C of different concentrations for 7 days. Body weight, viral titer, lung pathology, and mortality of the mice were measured, and the level of inflammatory cytokines was also examined using real-time RT-qPCR.

Results

CQ-C inhibited the proliferation of influenza virus of various strains in vitro, with the 50% inhibitory concentration (IC50) ranging from 49 to 59 µg/mL. CQ-C downregulated virus-induced gene expression of IL-6, TNF-α, CXCL8, CXCL10, CCL5, and COX-2 in a dose-dependent manner in A549 cells. Also, CQ-C inhibited the expression of NF-κB protein of the signaling pathway. Moreover, a decrease of the lung index and mortality of mice was observed in the CQ-C (1 g/kg/d) group. The related cytokine/chemokine expression was also decreased in the early stages of infection in the mRNA level.

Conclusion

As a clinically applied Chinese prescription, our study shows that CQ-C has a wide range of effects on several influenza viruses. Moreover, CQ-C could play an important role in anti-influenza activity and anti-inflammation in vitro and in vivo. Thus, CQ-C may be a promising treatment option for influenza.

Influence of rosuvastatin treatment on cerebral inflammation and nitro-oxidative stress in experimental lung injury in pigs

BACKGROUND

Many patients with acute respiratory distress syndrome (ARDS) suffer from cognitive impairment after hospital discharge. Different mechanisms have been implicated as potential causes for this impairment, inter alia cerebral inflammation. A class of drugs with antioxidant and anti-inflammatory properties are β-HMG-CoA-reductase inhibitors ("statins"). We hypothesized that treatment with rosuvastatin attenuates cerebral cytokine mRNA expression and nitro-oxidative stress in an animal model of acute lung injury.

METHODS

After approval of the institutional and state animal care committee, we performed this prospective randomized controlled animal study in accordance with the international guidelines for the care and use of laboratory animals. Thirty-two healthy male pigs were randomized to one of four groups: lung injury by central venous injection of oleic acid (n = 8), statin treatment before and directly after lung injury (n = 8), statin treatment after lung injury (n = 8), or ventilation-only controls (n = 8). About 18 h after lung injury and standardized treatment, the animals were euthanised, and the brains and lungs were collected for further examinations. We determined histologic lung injury and cerebral and pulmonal cytokine and 3-nitrotyrosine production.

RESULTS

We found a significant increase in hippocampal IL-6 mRNA after lung injury (p < 0.05). Treatment with rosuvastatin before and after induction of lung injury led to a significant reduction of hippocampal IL-6 mRNA (p < 0.05). Cerebral 3-nitrotyrosine was significantly higher in lung-injured animals compared with all other groups (p < 0.05 vs. animals treated with rosuvastatin after lung injury induction; p < 0.001 vs. all other groups). 3-Nitrotyrosine was also increased in the lungs of the lung-injured pigs compared to all other groups (p < 0.05 each).

CONCLUSIONS

Our findings highlight cerebral cytokine production and nitro-oxidative stress within the first day after induction of lung injury. The treatment with rosuvastatin reduced IL-6 mRNA and 3-nitrotyrosine concentration in the brains of the animals. In earlier trials, statin treatment did not reduce mortality in ARDS patients but seemed to improve quality of life in ARDS survivors. Whether this is attributable to better cognitive function because of reduced nitro-oxidative stress and inflammation remains to be elucidated.

The immunological link between neonatal lung and eye disease

Bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP) are two neonatal diseases of major clinical importance, arising in large part as a consequence of supplemental oxygen therapy used to promote the survival of preterm infants. The presence of coincident inflammation in the lungs and eyes of neonates receiving oxygen therapy indicates that a dysregulated immune response serves as a potential common pathogenic factor for both diseases. This review examines the current state of knowledge of immunological dysregulation in BPD and ROP, identifying similarities in the cellular subsets and inflammatory cytokines that are found in the alveoli and retina during the active phase of these diseases, indicating possible mechanistic overlap. In addition, we highlight gaps in the understanding of whether these responses emerge independently in the lung and retina as a consequence of oxygen exposure or arise because of inflammatory spill-over from the lung. As BPD and ROP are anatomically distinct, they are often considered discreet disease entities and are therefore treated separately. We propose that an improved understanding of the relationship between BPD and ROP is key to the identification of novel therapeutic targets to treat or prevent both conditions simultaneously.

Alpha-1 antitrypsin deficiency research and emerging treatment strategies: what's down the road?

Intravenous infusion of alpha-1 antitrypsin (AAT) was approved by the United States Food and Drug Administration (FDA) to treat emphysema associated with AAT deficiency (AATD) in 1987 and there are now several FDA-approved therapy products on the market, all of which are derived from pooled human plasma. Intravenous AAT therapy has proven clinical efficacy in slowing the decline of lung function associated with AATD progression; however, it is only recommended for individuals with the most severe forms of AATD as there is a lack of evidence that this treatment is effective in treating wild-type heterozygotes (e.g., PI*MS and PI*MZ genotypes), for which the prevalence may be much higher than previously thought. There are large numbers of individuals that are currently left untreated despite displaying symptoms of AATD. Furthermore, not all countries offer AAT augmentation therapy due to its expense and inconvenience for patients. More cost-effective treatments are now being sought that show efficacy for less severe forms of AATD and many new therapeutic technologies are being investigated, such as gene repair and other interference strategies, as well as the use of chemical chaperones. New sources of AAT are also being investigated to ensure there are enough supplies to meet future demand, and new methods of assessing response to treatment are being evaluated. There is currently extensive research into AATD and its treatment, and this chapter aims to highlight important emerging treatment strategies that aim to improve the lives of patients with AATD.

Differences of TNF-α, IL-6 and Gal-3 in lobar pneumonia and bronchial pneumonia caused by mycoplasma pneumoniae

OBJECTIVE

To investigate the differences of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and galectin-3 concentrations in lobar pneumonia and bronchopneumonia induced by mycoplasma pneumoniae (MP) in children and to explore these related factors predicting the severity of MP.

METHODS

A total of 148 children with mycoplasma pneumoniae pneumonia (MPP) and 32 healthy controls were analyzed from March 2017 to August 2018 in our province. Clinical information was collected from the hospitalized MP patients. The 148 patients with MPP were divided into two groups: lobar pneumonia group and bronchial pneumonia group. The 32 healthy children were considered the control group. The concentrations of TNF-α, IL-6 and Gal-3 were examined in the serum of 148 children patients with MPP and 32 healthy children by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

The TNF-α, IL-6 and Gal-3 levels were obviously higher in both the lobar pneumonia and bronchial pneumonia groups, compared to those in the control group. Furthermore, these levels were significantly higher in the lobar pneumonia group, compared to the bronchial pneumonia group. After treatment, the levels of TNF-α, IL-6 and Gal-3 totally descended during the recovery period.

CONCLUSION

There are differences in serum TNF-α, IL-6 and Gal-3 concentrations in lobar pneumonia and bronchial pneumonia caused by MP in children. In general, the TNF-α, IL-6 and Gal-3 levels were significantly higher in the lobar pneumonia group, when compared to the bronchial pneumonia group. This was because most lobar pneumonia cases are much more serious than bronchial pneumonia. Moreover, it has been proven that TNF-α, IL-6 and Gal-3 may play an important role in the pathogenesis development of MPP. At the same time, these are important issues in diagnosing MPP.

Pulmonary injury and oxidative stress in rats induced by inhaled sulfur mustard is ameliorated by anti-tumor necrosis factor-α antibody

Sulfur mustard (SM) is a bifunctional alkylating agent that causes severe injury to the respiratory tract. This is accompanied by an accumulation of macrophages in the lung and the release of the proinflammatory cytokine, tumor necrosis factor (TNF)α. In these studies, we analyzed the effects of blocking TNFα on lung injury, inflammation and oxidative stress induced by inhaled SM. Rats were treated with SM vapor (0.4 mg/kg) or air control by intratracheal inhalation. This was followed 15-30 min later by anti-TNFα antibody (15mg/kg, i.v.) or PBS control. Animals were euthanized 3 days later. Anti-TNFα antibody was found to blunt SM-induced peribronchial edema, perivascular inflammation and alveolar plasma protein and inflammatory cell accumulation in the lung; this was associated with reduced expression of PCNA in histologic sections and decreases in BAL levels of fibrinogen. SM-induced increases in inflammatory proteins including soluble receptor for glycation end products, its ligand, high mobility group box-1, and matrix metalloproteinase-9 were also reduced by anti-TNFα antibody administration, along with increases in numbers of lung macrophages expressing TNFα, cyclooxygenase-2 and inducible nitric oxide synthase. This was correlated with reduced oxidative stress as measured by expression of heme oxygenase-1 and Ym-1. Together, these data suggest that inhibiting TNFα may represent an efficacious approach to mitigating acute lung injury, inflammatory macrophage activation, and oxidative stress induced by inhaled sulfur mustard.

A cross-linked anti-TNF-α aptamer for neutralization of TNF-α-induced cutaneous Shwartzman phenomenon: A simple and novel approach for improving aptamers' affinity and efficiency

To increase the efficiency of aptamers to their targets, a simple and novel method has been developed based on aptamer oligomerization. To this purpose, previously anti-human TNF-α aptamer named T1-T4 was trimerized through a trimethyl aconitate core for neutralization of in vitro and in vivo of TNF-α. At first, 54 mer T1-T4 aptamers with 5'-NH₂ groups were covalently coupled to three ester residues in the trimethyl aconitate. In vitro activity of novel anti-TNF-α aptamer and its dissociation constant (K_d ) was done using the L929 cell cytotoxicity assay. In vivo anti-TNF-α activity of new oligomerized aptamer was assessed in a mouse model of cutaneous Shwartzman. Anchoring of three T1-T4 aptamers to trimethyl aconitate substituent results in formation of the 162 mer fragment, which was well revealed by gel electrophoresis. In vitro study indicated that the trimerization of T1-T4 aptamer significantly improved its anti-TNF-α activity compared to non-modified aptamers (P < 0.0001) from 40% to 60%. The determination of K_d showed that trimerization could effectively enhance K_d of aptamer from 67 nM to 36 nM. In vivo study showed that trimer aptamer markedly reduced mean scar size from 15.2 ± 1.2 mm to 1.6 ± 0.1 mm (P < 0.0001), which prevent the formation of skin lesions. In vitro and in vivo studies indicate that trimerization of anti-TNF-α aptamer with a novel approach could improve the anti-TNF-α activity and therapeutic efficacy. According to our findings, a new anti-TNF-α aptamer described here could be considered an appropriate therapeutic agent in treating several inflammatory diseases.

Effects of tumor necrosis factor (TNF) gene polymorphisms on the association between smoking and lung function among workers in swine operations

Workers in swine operations may be at increased risk of developing respiratory problems. These respiratory conditions are more prevalent among workers who are smokers. Tumor necrosis factor (TNF) genes play an important role in human immune responses to various respiratory hazards. This study aimed to investigate whether polymorphisms in TNF genes might alter the effects of smoking on lung function among workers in swine operations. Three hundred and seventy-four full-time workers from large swine operations and 411 non-farming rural dwellers in Saskatchewan were included in this study. Information on demographic and lifestyle characteristics, pulmonary function, and blood samples were obtained. Multiple linear regression analyses were used in the statistical analysis. Three promoter polymorphisms (rs1799724, rs361525, and rs1800629) in the TNF gene were investigated. Only the interaction term between smoking status and rs1799724 was significant in the multiple regression models. Among workers with the rs1799724 polymorphism (TT+TC), current smokers exhibited significantly lower lung function than nonsmokers. These associations were not observed among workers with the wild-type (CC). These findings were not observed among non-farming rural dwellers. Data demonstrated the possible involvement of TNF gene in (1) development of adverse respiratory conditions among workers who are smokers, (2) importance of smoking cessation among workers, especially those with polymorphisms in the TNF gene, and (3) potential implications in treatment, screening, and prevention.

Knockout of PKC θ gene attenuates oleic acid-induced acute lung injury via reduction of inflammation and oxidative stress

OBJECTIVES

Acute respiratory distress syndrome resulting from acute lung injury has become a momentous clinical concern because of high morbidity and mortality in discharged patients with pulmonary and nonpulmonary diseases. This study aimed to explore the effect of protein kinase C (PKC) θ gene knockout on acute lung injury.

MATERIALS AND METHODS

Wt and PKC θ gene knockout mice were intravenously injected with oleic acid to induce acute lung injury. Pulmonary capillary permeability was assessed via measuring lung wet/dry weight ratio and level of protein in bronchoalveolar lavage fluid (BALF). Histological changes were used to examine acute lung injury. Malondialdehyde (MDA) level, superoxide dismutase (SOD) activity in serum, together with inflammatory cytokines including interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α), were determined. Furthermore, the expressions of heme oxygenase (HO)-1, nuclear factor kappa B (NF κB), and inhibitor of NF-κB alpha (IκB α) were detected in the lungs.

RESULTS

PKC θ gene knockout decreased lung wet/dry weight ratio, reduced levels of MDA, IL-6, and TNF-α in serum together with level of protein in BALF. Furthermore, PKC θ gene knockout increased the activities of SOD. Knockout of PKC θ was also observed to increase expression of HO-1 and reduce levels of p-NF κB and p-IKB α in the lungs.

CONCLUSION

These results suggest that PKC θ gene knockout attenuates oleic acid-induced acute lung injury via improving oxidative stress and inflammation.

Interplay of Inflammatory, Antigen and Tissue-Derived Signals in the Development of Resident CD8 Memory T Cells

CD8 positive, tissue resident memory T cells (TRM) are a specialized subset of CD8 memory T cells that surveil tissues and provide critical first-line protection against tumors and pathogen re-infection. Recently, much effort has been dedicated to understanding the function, phenotype and development of TRM. A myriad of signals is involved in the development and maintenance of resident memory T cells in tissue. Much of the initial research focused on the roles tissue-derived signals play in the development of TRM, including TGFß and IL-33 which are critical for the upregulation of CD69 and CD103. However, more recent data suggest further roles for antigenic and pro-inflammatory cytokines. This review will focus on the interplay of pro-inflammatory, tissue and antigenic signals in the establishment of resident memory T cells.

TNF-mediated alveolar macrophage necroptosis drives disease pathogenesis during respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the major cause of acute bronchiolitis in infants under 2 years old. Necroptosis has been implicated in the outcomes of respiratory virus infections. We report that RSV infection triggers necroptosis in primary mouse macrophages and human monocytes in a RIPK1-, RIPK3- and MLKL-dependent manner. Moreover, necroptosis pathways are harmful to RSV clearance from alveolar macrophages. Additionally, Ripk3^-/- mice were protected from RSV-induced weight loss and presented with reduced viral loads in the lungs.Alveolar macrophage depletion also protected mice from weight loss and decreased lung RSV virus load. Importantly, alveolar macrophage depletion abolished the upregulation of Ripk3 and Mlkl gene expression induced by RSV infection in the lung tissue.Autocrine tumor necrosis factor (TNF)-mediated RSV-triggered macrophage necroptosis and necroptosis pathways were also involved in TNF secretion even when macrophages were committed to cell death, which can worsen lung injury during RSV infection. In line, Tnfr1^-/- mice had a marked decrease in Ripk3 and Mlkl gene expression and a sharp reduction in the numbers of necrotic alveolar macrophages in the lungs. Finally, we provide evidence that elevated nasal levels of TNF are associated with disease severity in infants with RSV bronchiolitis.We propose that targeting TNF and/or the necroptotic machinery may be valuable therapeutic approaches to reduce the respiratory morbidity caused by RSV infection in young children.

Multilevel systems biology analysis of lung transcriptomics data identifies key miRNAs and potential miRNA target genes for SARS-CoV-2 infection

Background

The spread of a novel severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) has affected both the public health and the global economy. The current study was aimed at analysing the genetic sequence of this highly contagious corona virus from an evolutionary perspective, comparing the genetic variation features of different geographic strains, and identifying the key miRNAs as well as their gene targets from the transcriptome data of infected lung tissues.

Methods

A multilevel robust computational analysis was undertaken for viral genetic sequence alignment, phylogram construction, genome-wide transcriptome data interpretation of virus-infected lung tissues, miRNA mapping, and functional biology networking.

Results

Our findings show both genetic similarities as well as notable differences in the S protein length among SARS-CoV-1, SARS-CoV-2 and MERS viruses. All SARS-CoV-2 strains showed a high genetic similarity with the parent Wuhan strain, but Saudi Arabian, South African, USA, Russia and New Zealand strains carry 3 additional genetic variations like P333L (RNA -dependant RNA polymerase), D614G (spike), and P4715L (ORF1ab). The infected lung tissues demonstrated the upregulation of 282 (56.51%) antiviral defensive response pathway genes and downregulation of 217 (43.48%) genes involved in autophagy and lung repair pathways. By miRNA mapping, 4 key miRNAs (hsa-miR-342-5p, hsa-miR-432-5p, hsa-miR-98-5p and hsa-miR-17-5p), targeting multiple host genes (MYC, IL6, ICAM1 and VEGFA) as well as SARS-CoV2 gene (ORF1ab) were identified.

Conclusion

Systems biology methods offer a new perspective in understanding the molecular basis for the faster spread of SARS-CoV-2 infection. The antiviral miRNAs identified in this study may aid in the ongoing search for novel personalized therapeutic avenues for COVID patients.

Anti-VEGF treatment suppresses remodeling factors and restores epithelial barrier function through the E-cadherin/β-catenin signaling axis in experimental asthma models

Besides maintaining a physical barrier with adherens junctional (AJ) and tight junctional proteins, airway epithelial cells have important roles in modulating the inflammatory processes of allergic asthma. E-cadherin and β-catenin are the key AJ proteins that are involved in airway remodeling. Various mediators such as transforming growth factor-β (TGF-β), epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet derived growth factor (PDGF), insulin-like growth factor (IGF), tumor necrosis factor-α (TNF-α) and angiogenic factors, such as vascular endothelial growth factor (VEGF), are released by the airway epithelium in allergic asthma. The signaling pathways activated by these growth factors trigger epithelial-mesenchymal transition (EMT), which contributes to fibrosis and subsequent downregulation of E-cadherin. The present study used a mouse asthma model to investigate the effects of anti-VEGF, anti-TNF and corticosteroid therapies on growth factor and E-cadherin/β-catenin expression. The study used 38 male BALB/c mice, divided into 5 groups. A chronic mouse asthma model was created by treating 4 of the groups with inhaled and intraperitoneal ovalbumin (n= 8 per group). Saline, anti-TNF-α (etanercept), anti-VEGF (bevacizumab) or a corticosteroid (dexamethasone) were applied to each group by intraperitoneal injection. No medication was administered to the control group (n=6). Immunohistochemistry for E-cadherin, β-catenin and growth factors was performed on lung tissues and protein expression levels assessed using H-scores. Statistically significant differences were observed in E-cadherin, β-catenin, EGF, FG, and PFGF (P<0.001 for all) as well as the IGF H-scores between the five groups (P<0.005). Only anti-VEGF treatment caused E-cadherin and β-catenin levels to increase to the level of non-asthmatic control groups (P>0.005). All treatment groups had reduced TGF-β, PDGF and FGF H-scores in comparison with the untreated asthma group (P=0.001). The EGF and IGF levels were not significantly different between the untreated asthmatic and non-asthmatic controls. The results suggested that anti-VEGF and TNF-α inhibition treatments are effective in decreasing growth factors, in a similar manner to conventional corticosteroid treatments. Anti-VEGF and TNF inhibition therapy may be an effective treatment for remodeling in asthma while offering an alternative therapeutic option to steroid protective agents. The data suggested that anti-VEGF treatment offered greater restoration of the epithelial barrier than both anti-TNF-α and corticosteroid treatment.

Targeting Runt-Related Transcription Factor 1 Prevents Pulmonary Fibrosis and Reduces Expression of Severe Acute Respiratory Syndrome Coronavirus 2 Host Mediators

Pulmonary fibrosis (PF) can arise from unknown causes, as in idiopathic PF, or as a consequence of infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current treatments for PF slow, but do not stop, disease progression. We report that treatment with a runt-related transcription factor 1 (RUNX1) inhibitor (Ro24-7429), previously found to be safe, although ineffective, as a Tat inhibitor in patients with HIV, robustly ameliorates lung fibrosis and inflammation in the bleomycin-induced PF mouse model. RUNX1 inhibition blunted fundamental mechanisms downstream pathologic mediators of fibrosis and inflammation, including transforming growth factor-β1 and tumor necrosis factor-α, in cultured lung epithelial cells, fibroblasts, and vascular endothelial cells, indicating pleiotropic effects. RUNX1 inhibition also reduced the expression of angiotensin-converting enzyme 2 and FES Upstream Region (FURIN), host proteins critical for SARS-CoV-2 infection, in mice and in vitro. A subset of human lungs with SARS-CoV-2 infection overexpress RUNX1. These data suggest that RUNX1 inhibition via repurposing of Ro24-7429 may be beneficial for PF and to battle SARS-CoV-2, by reducing expression of viral mediators and by preventing respiratory complications.

Myeloid cell dynamics in bleomycin-induced pulmonary injury in mice; effects of anti-TNFα antibody

Bleomycin is a cancer therapeutic known to cause lung injury which progresses to fibrosis. Evidence suggests that macrophages contribute to this pathological response. Tumor necrosis factor (TNF)α is a macrophage-derived pro-inflammatory cytokine implicated in lung injury. Herein, we investigated the role of TNFα in macrophage responses to bleomycin. Treatment of mice with bleomycin (3 U/kg, i.t.) caused histopathological changes in the lung within 3 d which culminated in fibrosis at 21 d. This was accompanied by an early (3-7 d) influx of CD11b+ and iNOS+ macrophages into the lung, and Arg-1+ macrophages at 21 d. At this time, epithelial cell dysfunction, defined by increases in total phospholipids and SP-B was evident. Treatment of mice with anti-TNFα antibody (7.5 mg/kg, i.v.) beginning 15-30 min after bleomycin, and every 5 d thereafter reduced the number and size of fibrotic foci and restored epithelial cell function. Flow cytometric analysis of F4/80+ alveolar macrophages (AM) isolated by bronchoalveolar lavage and interstitial macrophages (IM) by tissue digestion identified resident (CD11b-CD11c+) and immature infiltrating (CD11b+CD11c-) AM, and mature (CD11b+CD11c+) and immature (CD11b+CD11c-) IM subsets in bleomycin treated mice. Greater numbers of mature (CD11c+) infiltrating (CD11b+) AM expressing the anti-inflammatory marker, mannose receptor (CD206) were observed at 21 d when compared to 7 d post bleomycin. Mature proinflammatory (Ly6C+) IM were greater at 7 d relative to 21 d. These cells transitioned into mature anti-inflammatory/pro-fibrotic (CD206+) IM between 7 and 21 d. Anti-TNFα antibody heightened the number of CD11b+ AM in the lung without altering their activation state. Conversely, it reduced the abundance of mature proinflammatory (Ly6C+) IM in the tissue at 7 d and immature pro-fibrotic IM at 21 d. Taken together, these data suggest that TNFα inhibition has beneficial effects in bleomycin induced injury, restoring epithelial function and reducing numbers of profibrotic IM and the extent of pulmonary fibrosis.

[Role of prostacyclin and thromboxane A2 in pulmonary hyper-permeability induced by mechanical ventilation in rabbits]

OBJECTIVE

To explore the role of prostacyclin (PGI2) and thromboxane A2 (TXA2) in lung hyper-permeability induced by mechanical ventilation (MV) in rabbits.

OBJECTIVE

Forty-eight healthy Japanese white rabbits were randomly allocated to vehicle treatment group (group V), tranylcypromine (a PGI2 synthase inhibitor) treatment group (group T), dazoxiben (a TXA2 synthase inhibitor) treatment group (group D), vehicle-treated MV group (group VM), tranylcyprominetreated MV group (group TM) and dazoxiben-treated MV group (group DM). The contents of PGI2 and TXA2 in the lung tissues and TNF-α level in BALF and lung tissues were measured by ELISA. The lung wet/dry weight (W/D) ratio, lung permeability index and pulmonary expressions of myosin light chain kinase (MLCK) protein and mRNA were detected to evaluate the pulmonary permeability. The severities of lung injury were assessed by lung histological scores.

OBJECTIVE

The measured parameters did not differ significantly among the rabbits receiving different treatments without MV. In rabbits in group VM, the contents of PGI2 and TXA2 in the lungs, TNF-α in BALF and lung tissues, PGI2/TXA2 ratio, lung W/D ratio, lung permeability index, pulmonary expressions of MLCK protein and mRNA and histological scores of the lungs all increased significantly (P < 0.05) as compared with those in group V, group T and group D. In rabbits undergoing MV, inhibition of PGI2 production by tranylcypromine significantly decreased the PGI2/TXA2 ratio (P < 0.05), further enhanced the production of TNF-α in the BALF and lung tissue (P < 0.05), and worsened lung hyper-permeability and lung injury (P < 0.05), while treatment with dazoxiben significantly reduced TXA2 production in the lung tissue (P < 0.05), increased the PGI2/TXA2 ratio (P < 0.05) and decreased TNF-α production in the BALF and lung tissue (P < 0.05), thus resulting in alleviated lung hyperpermeability and lung injury (P < 0.05).

OBJECTIVE

PGI2 plays a protective role against MV-induced lung hyper-permeability and lung injury by downregulating TNF-α/MLCK signaling pathway, while TXA2 can exacerbate MV-induced lung hyperpermeability in rabbits by up-regulating TNF-α/ MLCK signaling pathway.