Glutathione attenuates diesel exhaust-induced lung epithelial injury via NF-κB/Nrf2/GPX4-mediated ferroptosis

Diesel exhaust (DE) emissions pose a significant threat to public health. This study linked DE-mediated reactive oxygen species (ROS) and ferroptosis with lung epithelial disruption, also the protective potential of exogenous glutathione (GSH) administration was investigated. C57BL/6 mice were divided into three groups: filtered air (control), DE exposed, and DE+GSH (administered intranasally on alternate days). Airway hyperresponsiveness (AHR), lung tissues, and bronchoalveolar lavage fluid (BALF) were used for analysis. DE exposure significantly impaired lung function parameters as shown by AHR. Elevated ROS depleted the GSH/GSSG ratio and suppressed Nrf2 activity, disrupting antioxidant defense mechanisms, which were restored by GSH administration. DE-induced ROS acted as a key driver of ferroptosis, characterized by suppressed SLC7411 expression thereby decreased GSH synthesis and GPX-4 activity, inducing lipid peroxidation. Ferroptosis was significantly mitigated by increased GSH pool, which restored GPX-4 levels and reduced lipid peroxidation. Concurrently, DE induced ROS promoted DNA damage and apoptosis in lung epithelial cells wherein GSH treatment preserved cell survival in DE exposed mice. The heightened DE-associated ROS further amplified inflammation, as shown by increased cytokines (TNF-α, IL-6, TSLP, IL-33) and P-NF-κB activation. Activated inflammatory cascade disrupted tight junction proteins (claudins, occludin), resulted in weakened epithelial barrier and increased permeability. Lung barrier disruption was evidenced by transmission electron microscopy and immunohistochemistry, corroborated with elevated albumin levels. GSH effectively restored tight junction integrity and preserved barrier function in DE+GSH mice lungs. In conclusion, DE-induced oxidative stress and ferroptosis-triggered inflammation compromised epithelial barrier promoting lung injury. Exogenous GSH administration showed potential in restoring DE-associated lung damage.

Molecular mechanism of rapamycin-induced autophagy activation to attenuate smoking-induced COPD

Chronic obstructive pulmonary disease (COPD) is one of the severe lung and respiratory airway disorders, with high prevalence rate in China. In this paper, we employed network pharmacology predictions to identify autophagy as a signaling pathway associated with COPD. To explore the protective effect of autophagy against COPD and its specific mechanism, we established a mouse model of COPD and administered 3-methyladenine (3-MA) and rapamycin (RAPA) to intervene in autophagy. The lung function of the mice was assessed using an animal pulmonary function analysis system, and lung tissue structure was evaluated through hematoxylin and eosin (HE) staining. The TUNEL staining method was employed to determine the level of apoptosis in lung tissue. Western blot analysis was conducted to measure the expression of autophagy and apoptosis-related proteins, while RT-qPCR was used to assess the expression of apoptosis-related mRNA. The results showed that RAPA effectively improved lung function, attenuated pathological lung injury and increased autophagy level in COPD mice. Apoptosis analysis showed that the apoptosis rate was elevated in COPD and 3- MA mice, whereas it was significantly reduced in RAPA mice. Our findings suggest that stimulation of autophagy may be a potential therapy for the future treatment of COPD.

Acacetin Attenuates Cigarette Smoke Extract-Induced Human Bronchial Epithelial Cell Injury by Activating NRF2/SLC7A11/GPX4 Signaling to Inhibit Ferroptosis

Chronic obstructive pulmonary disease (COPD) stands as a major contributor to mortality worldwide, with cigarette smoke being a primary causative factor. Acacetin has been reported to possess lung protective effects. However, the precise role and mechanism of Acacetin in COPD remains elusive. In this study, human bronchial epithelial cell line HBE135-E6E7 was treated with Acacetin under cigarette smoke extract (CSE) conditions. Cellular viability was assessed using CCK-8 and LDH kits. Reactive oxygen species (ROS) generation was tested with DCFH-DA staining. JC-1 staining was employed to examine the mitochondrial membrane potential (MMP). Additionally, hydroxynonenal (4-HNE) level was tested using immunofluorescence staining and mitochondrial lipid peroxidation was evaluated using MitoPeDPP staining. MitoSOX staining was used to detect mitochondrial (mito)-ROS. Fe2+ level was measured using FerroOrange staining and the expression of ferroptosis-related proteins was detected with western blot. Besides, the binding between Acacetin and NRF2 was analyzed by molecular docking. The sequent NRF2 overexpression or knockdown was used to explore the regulation of Acacetin on NRF2/SLC7A11/GPX4 signaling. Results indicated that CSE significantly reduced the viability, augmented ROS generation and decreased MMP in HBE135-E6E7 cells, which were blocked by Acacetin addition. Moreover, Acacetin inhibited lipid peroxidation and ferroptosis in CSE-treated HBE135-E6E7 cells. Specifically, Acacetin targeted NRF2 and activated the NRF2/SLC7A11/GPX4 signaling in CSE-induced HBE135-E6E7 cells. Furthermore, NRF2 deficiency or ML-385 treatment notably restored the influences of Acacetin on oxidative stress and ferroptosis in HBE135-E6E7 cells challenged with CSE. In conclusion, Acacetin alleviated CSE-induced injury in HBE135-E6E7 cells by activating The NRF2/SLC7A11/GPX4 signaling to inhibit ferroptosis.

COPD susceptibility gene HHIP regulates repair genes in airway epithelial cells and repair within the epithelial-mesenchymal trophic unit

The role of the chronic obstructive pulmonary disease (COPD) susceptibility gene hedgehog (Hh) interacting protein (HHIP) in lung tissue damage and abnormal repair in COPD is incompletely understood. We hypothesized that dysregulated HHIP expression affects cigarette smoke-induced epithelial damage and repair within the epithelial-mesenchymal trophic unit. HHIP expression was assessed in lung tissue and airway epithelial cells (AECs) from patients with COPD and non-COPD controls. The effect of HHIP overexpression was assessed on cigarette smoke extract (CSE)-induced changes in epithelial plasticity genes, for example, cadherin 1 (CDH1, encoding E-cadherin) in human bronchial epithelial cells (16HBE) cells, and on epithelial-mesenchymal interactions during alveolar repair as modeled by organoid formation using distal lung-derived mesenchymal stromal cells (LMSCs) and EpCAM+ epithelial cells. We observed no abnormalities in HHIP protein levels in the lung tissue of patients with COPD, whereas the expression of HHIP was significantly lower in COPD-derived AECs compared with the control. HHIP overexpression in 16HBE cells attenuated the CSE-induced reduction in CDH1 expression. Furthermore, overexpression of HHIP significantly suppressed Sonic hedgehog-induced GLI1 expression in control but not COPD-derived LMSCs and resulted in the formation of more and larger organoids, which was not observed for COPD-derived LMSCs. This defect was accompanied by lower expression of the growth factor FGF10 upon HHIP overexpression in COPD compared with control-derived LMSCs. Together, our data suggest a protective role of HHIP in CSE-induced airway epithelial responses and a supportive role in alveolar epithelial regeneration, which may be impaired in COPD.NEW & NOTEWORTHY We show that overexpression of HHIP protected from cigarette smoke-induced epithelial-to-mesenchymal transition and promoted epithelial regeneration via epithelial-mesenchymal cross talk in non-COPD controls. Thus, the lower expression of HHIP in airway epithelial cells from patients with COPD may contribute to abnormal epithelial repair in both proximal and distal parts of the lungs of patients with COPD.

Chronic Obstructive Pulmonary Disease (COPD): Developments in Pharmacological Treatments

The immediate goals of pharmacological management in chronic obstructive pulmonary disease (COPD) are to minimise symptoms and improve exercise performance. The longer-term goals are to reduce the future risk of exacerbations, lung function decline and mortality. It is now recognised that a subset of COPD patients have type 2 inflammation, which is identified by the presence of higher blood eosinophil counts (BEC). Individuals with higher BEC show a greater response to pharmacological interventions targeting type 2 inflammation, including inhaled corticosteroids and the monoclonal antibody, dupilumab. The use of BEC as a biomarker to guide pharmacological treatment has enabled a precision medicine approach in COPD. This article reviews recent advances in the pharmacological treatment of COPD, encompassing the optimum use of inhaled combination treatments and the evidence to support the use of the novel inhaled phosphodiesterase inhibitor ensifentrine and monoclonal antibodies in patients with COPD.

Disulfiram alleviates epithelial barrier disruption in ozone-induced chronic obstructive pulmonary disease mouse models via inhibiting Gasdermin D-mediated pyroptosis

BACKGROUND

Gasdermin D (GSDMD)-mediated pyroptosis drives inflammatory cytokine release in response to environmental triggers. Disulfiram (DSF), an FDA-approved anti-alcoholism drug, has been demonstrated to inhibit GSDMD pore formation. Although airway epithelial barrier dysfunction contributes to chronic obstructive pulmonary disease (COPD) progression, the role of GSDMD-dependent pyroptosis in ozone-induced pathogenesis, and the potential of DSF to inhibit this process, remain unexplored.

METHODS

We analyzed the expression levels of pyroptosis-related molecules in airway epithelial cells from COPD patients' samples obtained from the Gene Expression Omnibus (GEO) database and evaluated the potential therapeutic effects of DSF in a mouse model of COPD induced by chronic ozone exposure.

RESULTS

GSDMD was significantly upregulated in the airway epithelial cells of COPD patients. Chronic ozone exposure in mice elevated the cleaved form of GSDMD and reduced the expression of epithelial junctional proteins. DSF treatment effectively inhibited GSDMD-mediated pyroptosis and attenuated epithelial barrier disruption, leading to significant improvements in airway inflammation and lung function in both large and small airways. Furthermore, Gsdmd expression was negatively correlated with the tight junction protein Occludin and pulmonary function indices, including the ratio of FEV25 to FVC and MMEF.

CONCLUSION

Collectively, these findings revealed the role of GSDMD-mediated pyroptosis in epithelial barrier disruption of COPD and the potential application of DSF in the treatment of COPD.

Mechanisms and potential roles of active ingredients of traditional Chinese medicine in the treatment of chronic obstructive pulmonary disease

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is a respiratory condition with high rates of morbidity and mortality. Recent studies have shown that the increasing research on Traditional Chinese Medicine (TCM) also plays an important role in COPD. The purpose of this review is to categorize TCM and its active ingredients and to summarize their pharmacological effects.

METHODS

Articles published up to December 2024 were searched through PubMed, X-MOL, and the China National Knowledge Infrastructure. The keywords included TCM and its combination with COPD, pharmacologic activity, anti-inflammatory effects, pharmacology, as well as in vivo and in vitro studies.

KEY FINDINGS

Thus far, we have summarized the progress of research on the mechanisms of action of TCM and its active ingredients, such as flavonoids, terpenoids, and phenols, in the treatment of COPD. These mechanisms encompass the reduction of inflammatory responses and lung injury, regulation of the oxidation-antioxidation balance, and modulation of cellular apoptosis and aging, among other effects.

CONCLUSION

TCM and its active ingredients demonstrate strong anti-COPD properties. This provides a reference for accelerating the development of herbal components for the treatment of COPD and for exploring new potential multi-target therapeutic mechanisms. This will mitigate the geographical limitations of using TCM and enhance its application in future management strategies.

Where There is Smoke: An Updated Review of Environmental Contributions to Chronic Rhinosinusitis

PURPOSE

The pathogenesis of chronic rhinosinusitis (CRS) is thought to include a complex interaction between environmental exposures and host immune responses that generates a self-perpetuating inflammatory process. As molecular pathways continue to be explored, the impact of environmental exposures on CRS pathogenesis and exacerbation must not be overlooked. This review will explore the association between environmental exposures and CRS, specifically focusing on tobacco smoke, occupational inhalational exposures, air pollution, particulate matter, and wildfire smoke.

MAJOR FINDINGS

Tobacco smoke is associated with increased prevalence of CRS symptoms and formal diagnosis with worse surgical outcomes observed in both adults and children exposed to tobacco smoke. Numerous occupational exposures have been associated with increased sinonasal symptoms, though exposures and disease definitions are often poorly characterized. Pollution and microparticle exposure has been associated with an increased likelihood of CRS diagnosis, as well as increased need for surgery. Last, while wildfire smoke has been attributed to increased hospital and emergency room visits for respiratory-related complaints, no primary research has yet been performed regarding CRS and wildfire smoke, though in-vitro studies support an association.

CONCLUSIONS

Population-based studies bolstered by in-vitro mechanistic data support an association between numerous environmental exposures and the onset and severity of CRS.

Protective effect of aqueous extract of Reineckea carnea (Andrews) Kunth against cigarette smoke-induced chronic obstructive pulmonary disease in mice and its impact on gut microbiota

Reineckea carnea (Andrews) Kunth (RCK) is known for its anti-inflammatory and antioxidant effects. But, its effects and underlying mechanisms on chronic obstructive pulmonary disease (COPD) are not well understood. This study aimed to evaluate the effects of RCK on COPD and to elucidate the mechanisms by which it modulates gut microbiota. A COPD mouse model was established through exposure to cigarette smoke (CS). Mice were then treated with oral administration of RCK aqueous extract. The anti-inflammatory effects and efficacy of RCK aqueous extract on COPD, as well as changes in microbiota composition, were evaluated. RCK aqueous extract ameliorated gut dysbiosis in CS-induced COPD mice by increasing the abundance of beneficial bacterial phyla and reducing the proliferation of pathogenic bacteria. Importantly, RCK treatment inhibited the expression of inflammatory mediators, such as IL-6, IL-8, and TNF-α at both mRNA levels and protein levels, attenuated oxidative stress in vivo in mice, and suppressed CS-induced activation of the NF-κB signaling pathway, thereby attenuating lung inflammation and restoring lung tissue structure. In conclusion, the beneficial effects of RCK aqueous extract on CS-induced COPD may be attributed to its anti-inflammatory and antioxidant properties as well as its ability to modulate gut microbial composition.

FSP1 Acts in Parallel with GPX4 to Inhibit Ferroptosis in Chronic Obstructive Pulmonary Disease

GPX4 (glutathione peroxidase 4) has recently been reported to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). FSP1 (ferroptosis suppressor protein-1) is a protein that defends against ferroptosis in parallel with GPX4, but its role in the pathogenesis of COPD remains unexplored, and further research is needed. Normal and COPD lung tissues were obtained from lobectomy and lung transplant specimens, respectively. FSP1-overexpressing mice were established by monthly transfection with adenoassociated virus 9-FSP1 through modified intranasal administration. The expression of FSP1, GPX4, and PTGS2 (prostaglandin-endoperoxide synthase 2) was measured by Western blotting, immunohistochemistry and other methods. The correlation between FSP1 and ferroptosis and the role of FSP1 in COPD were explored by screening the expression of ferroptosis-related genes in a COPD cell model after the inhibition and overexpression of FSP1. We then explored the underlying mechanism of low FSP1 expression in patients with COPD in vitro by methylated RNA immunoprecipitation quantitative qPCR. We found that cigarette smoke exposure can lead to an increase in lipid peroxide production and ultimately ferroptosis, which is negatively regulated by FSP1 activity. FSP1 overexpression can prevent ferroptosis and alleviate emphysema. Next, we found that decreased FSP1 expression was caused by increased N6-methyladenosine modification of FSP1 mRNA. Moreover, the level of FSP1 decreased in a YTHDF2-dependent manner. These results indicate that METTL3-induced FSP1 mRNA methylation leading to low FSP1 expression is a potential therapeutic target for COPD.

A predictive model for early postoperative hypoxemia after mitral valve replacement combined with pulmonary arterial hypertension

BACKGROUND

To establish and validate a novel scoring system on the basis of a nomogram for preoperative prediction of early hypoxemia after mitral valve replacement combined with pulmonary arterial hypertension.

METHODS

For this retrospective cohort study, clinical data from 430 patients with mitral valve disease combined with pulmonary arterial hypertension were collected. Early postoperative hypoxemia was defined as hypoxemia that occurred within 24 hours after operation. Clinical data from 430 patients were subjected to univariate logistic regression analysis (P < .05), and the results were then included in a stepwise multivariate logistic regression analysis (P < .05) to derive independent risk factors for postoperative hypoxemia. All the data from 430 patients were randomly divided into the training and validation cohorts. Nomogram prediction models for postoperative hypoxemia were established using the training cohorts and validated with the validation cohorts.

RESULTS

Univariate and stepwise multivariate logistic regression analyses suggested that the systolic pulmonary artery pressure, smoking, age, left atrial end-systolic dimension, and whether patients with accompanying atrial fibrillation underwent maze surgery (we replaced this factor with "atrial fibrillation-maze category" in the article that follows) were independent risk factors. A nomogram prediction model was developed accordingly. The area under the curve values of the training and validation cohorts were 0.838 (95% confidence interval, 0.783-0.892) and 0.799 (95% confidence interval, 0.730-0.869), respectively. The calibration curves were close to the ideal diagonal, and the decision curve analysis indicated a significant net benefit.

CONCLUSION

The risk prediction model developed in this study is a desirable predictor of early postoperative hypoxemia after mitral valve replacement combined with pulmonary arterial hypertension.

Spatiotemporal Clusters of Extracellular Signal-Regulated Kinase Activity Coordinate Cytokine-induced Inflammatory Responses in Human Airway Epithelial Cells

Spatially coordinated extracellular signal-regulated kinase (ERK) signaling events (SPREADs) transmit radially from a central point to adjacent cells via secreted ligands for EGFR (epidermal growth factor receptor) and other receptors. SPREADs maintain homeostasis in nonpulmonary epithelia, but it is unknown whether they play a role in the airway epithelium or are dysregulated in inflammatory disease. To address these questions, we measured SPREAD activity with live-cell ERK biosensors in human bronchial epithelial cell lines (HBE1 and 16HBE) and primary human bronchial epithelial cells, in both submerged and biphasic air-liquid interface culture conditions (i.e., differentiated cells). Airway epithelial cells were exposed to proinflammatory cytokines relevant to asthma and chronic obstructive pulmonary disease. Type 1 proinflammatory cytokines significantly increased the frequency of SPREADs, which coincided with epithelial barrier breakdown in differentiated primary human bronchial epithelial cells. Furthermore, SPREADs correlated with IL-6 peptide secretion and the appearance of localized clusters of phospho-STAT3 immunofluorescence. To probe the mechanism of SPREADs, cells were cotreated with pharmacological treatments (gefitinib, tocilizumab, hydrocortisone) or metabolic modulators (insulin, 2-deoxyglucose). Hydrocortisone, inhibitors of receptor signaling, and suppression of metabolic function decreased SPREAD occurrence, implying that proinflammatory cytokines and glucose metabolism modulate SPREADs in human airway epithelial cells via secreted EGFR and IL6R ligands. We conclude that spatiotemporal ERK signaling plays a role in barrier homeostasis and dysfunction during inflammation of the airway epithelium. This novel signaling mechanism could be exploited clinically to supplement corticosteroid treatment for asthma and chronic obstructive pulmonary disease.

Air pollutants and lung regeneration: impact on the fate of lung stem cells

Inhalable airborne pollutants, including particulate matter, ozone, cigarette smoke, and emerging microparticles and nanoparticles can initiate or exacerbate various lung diseases. Their toxicological impact depends not only on their chemical composition, but also on the host's capacity for clearance and post-injury repair mechanisms. Studies have identified region-specific stem cells within the lung epithelial-mucosal barrier, which are pivotal for mucosal repair after damage. This review delineates the roles of airway and alveolar key stem cells in lung epithelial mucosal repair, details how traditional and emerging airborne pollutants affect their regenerative capabilities. Additionally, it discusses the transformative contributions of organoids and single-cell sequencing technologies to advance our understanding of how inhaled pollutants affect lung tissue toxicity. A tissue regeneration perspective on the interplay between inhaled pollutants and lung stem cells is crucial for developing comprehensive strategies to prevent and control lung diseases associated with exposure to airborne pollutants.

Effect of age, COPD severity, and cigarette smoke exposure on bronchial epithelial barrier function

We investigated the effect of age, cigarette smoke, and chronic obstructive pulmonary disease (COPD) severity on epithelial barrier function. Primary bronchial epithelial cells (PBECs) were obtained from bronchial brushings in eight younger and eight older never-smokers; seven older ex-smokers without COPD, eight patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) I-III and six patients with COPD GOLD IV, and cultured in the absence/presence of cigarette smoke extract (CSE). Epithelial barrier function was assessed by electric resistance sensing and expression of junctional and antioxidant genes/proteins quantified by qPCR/immunodetection. Epithelial barrier function was comparable between PBECs from younger and older never-smokers. PBECs from ex-smokers had significantly lower barrier function compared with never-smokers, with a further decrease in COPD GOLD IV. CSE decreased epithelial barrier function from which PBECs from never-smokers, but not ex-smokers with and without COPD, recovered. Restoration of barrier function was accompanied by increased expression of barrier and antioxidant genes. At baseline, PBECs from ex-smokers with and without COPD had higher expression of junctional and antioxidant genes compared with never-smokers. However, exposure to CSE increased antioxidant (SOD1-3, CAT) gene expression only in PBECs from never-smokers and ex-smokers without COPD. In conclusion, our data indicate that cigarette smoking and COPD severity are associated with reduced epithelial barrier function, which is potentially driven by an imbalance in the antioxidant response.NEW & NOTEWORTHY Cigarette smoking and chronic obstructive pulmonary disease (COPD) severity are associated with reduced epithelial barrier function that is potentially driven by an imbalance in the antioxidant response.

SNAI2, a potential crossing point between cancer and cardiovascular disease

Cancer and cardiovascular disease remain the leading causes of morbidity and mortality worldwide, and the two separate disease entities share several similarities and possible interactions. Patients with cancer may have underlying cardiovascular disease, which is often exacerbated by the stress of tumor growth or treatment. At the same time, cardiotoxicity induced by anti-cancer therapies or the malignant process itself can lead to new cardiovascular diseases. Efforts have been made to find a rational explanation for this phenomenon. As a classical tumor-promoting factor, we notice that SNAI2 simultaneously plays an important pathogenic role in cardiovascular diseases. Moreover, there are several striking parallels in the mechanisms of cancer and CVD, such as shared risk factors (e.g., smoking and diabetes), cellular phenotypic switching, and metabolic remodeling, all of which are mediated by SNAI2. This review aims to summarize SNAI2's role in the core mechanisms linking cancer and CVD, as well as explore therapeutic approaches targeting SNAI2 and also seeks to provide insights into the common mechanisms underlying both cancer and CVD.

The Non-Antibacterial Effects of Azithromycin and Other Macrolides on the Bronchial Epithelial Barrier and Cellular Differentiation

The respiratory epithelium maintains the barrier against inhaled harmful agents. When barrier failure occurs, as in several respiratory diseases, acute or chronic inflammation leading to destructive effects and exacerbations can occur. Macrolides are used to treat a spectrum of infections but are also known for off-label use. Some macrolides, particularly azithromycin (AZM), reduce exacerbations in chronic obstructive pulmonary disease (COPD), whereby its efficacy is thought to be due to its effects on inflammation and oxidative stress. In vitro data indicate that AZM reduces epithelial barrier failure, evidenced by increased transepithelial electrical resistance (TEER). Here, we compared the effects of macrolides on differentiation and barrier integrity in VA10 cells, a bronchial epithelial cell line for 14 and 21 days. Erythromycin, clarithromycin, roxithromycin, AZM, solithromycin, and tobramycin (an aminoglycoside) were analyzed using RNA sequencing, barrier integrity assays, and immunostaining to evaluate effects on the epithelium. All macrolides affected the gene expression of pathways involved in epithelial-to-mesenchymal transition, metabolism, and immunomodulation. Treatment with AZM, clarithromycin, and erythromycin raised TEER and induced phospholipid retention. AZM treatment was distinct in terms of enhancement of the epithelial barrier, retention of phospholipids, vesicle build-up, and its effect on gene sets related to keratinocyte differentiation and establishment of skin barrier.

The PAR6B-PRKCI-PAR3 complex influences alveolar regeneration in patients with the emphysema subtype of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is gaining increasing attention, with different subtypes being distinguished for separate research and treatment. The emphysema subtype is characterized by widespread alveolar destruction, which may be associated with aggravated alveolar damage and abnormal repair. Type II alveolar epithelial cells (AEC2s), known for their stem cell potential, have recently emerged as a promising target for COPD treatment. However, to date, few studies have elucidated the specific mechanisms by which AEC2s induce alveolar regeneration.

METHODS

Lung tissue samples from COPD patients were collected, and bioinformatics analysis was used to identify expression profiles affecting the emphysema phenotype and target genes regulating AEC2 proliferation. In vitro models of smoke-induced injury and viral transfection were established to clarify the role of the target gene PARD6B in regulating AEC2s proliferation and transdifferentiation potential. Co-immunoprecipitation and mass spectrometry were employed to elucidate the specific regulatory mechanisms. Primary mouse AEC2s were isolated for 3D spheroid formation experiments to further validate the role of the target gene.

RESULTS

We observed impaired self-proliferation and enhanced transdifferentiation of AEC2s into AEC1s in lung tissues from COPD patients with emphysema subtype, which was associated with reduced expression of PARD6B. Interestingly, PARD6B primarily functioned as part of a complex in AEC2s. Mechanistically, we found that reduced levels of the PAR3-PARD6B-PRKCI complex could arrest the cell cycle of AEC2s in the G0-G1 phase, thereby impairing their self-proliferation.

CONCLUSIONS

Our findings reveal a novel regulatory mechanism for alveolar regeneration, highlighting a potential therapeutic target for managing the emphysema subtype of COPD.

The impact of health literacy on smoking patterns among male residents: insights from Ningbo City

Background

This study examined the associations between health literacy and smoking behaviors among residents in Ningbo City, Zhejiang Province, China, investigating both the impact of health literacy on smoking prevalence and intensity, and its potential role in smoking cessation interventions.

Methods

This cross-sectional study analyzed data from 2,948 male participants in the 2023 Health Literacy and Tobacco Use Surveillance Survey. We applied logistic regression models and restricted cubic spline analyses to assess the association between health literacy and smoking behaviors, adjusting for demographic characteristics, socioeconomic factors, and self-reported health status.

Results

Our findings indicate that higher levels of health literacy are associated with significantly lower rates of smoking (OR = 0.643, 95%CI = 0.528, 0.783) and daily cigarette consumption (β = -1.938, 95%CI = -3.649, -0.228). Non-smokers with higher health literacy were more likely to discourage others from smoking (OR = 1.464, 95%CI = 1.096, 1.955), underscoring health literacy's crucial role in smoking prevention and control. A nonlinear relationship between health literacy and smoking behavior was identified.

Conclusion

Health literacy significantly influences smoking behavior, with higher literacy levels associated with reduced smoking prevalence and intensity. These findings support incorporating health literacy enhancement into comprehensive smoking cessation strategies.

Development of a Widely Accessible, Advanced Large-Scale Microfluidic Airway-on-Chip

On-chip microfluidics are advanced in vitro models that simulate lung tissue's native 3D environment more closely than static 2D models to investigate the complex lung architecture and multifactorial processes that lead to pulmonary disease. Current microfluidic systems can be restrictive in the quantities of biological sample that can be retrieved from a single micro-channel, such as RNA, protein, and supernatant. Here, we describe a newly developed large-scale airway-on-chip model that employs a surface area for a cell culture wider than that in currently available systems. This enables the collection of samples comparable in volume to traditional cell culture systems, making the device applicable to any workflow utilizing these static systems (RNA isolation, ELISA, etc.). With our construction method, this larger culture area allows for easier handling, the potential for a wide range of exposures, as well as the collection of low-quantity samples (e.g., volatiles or mitochondrial RNA). The model consists of two large polydimethylsiloxane (PDMS) cell culture chambers under an independent flow of medium or air, separated by a semi-permeable polyethylene (PET) cell culture membrane (23 μm thick, 0.4 μm pore size). Each chamber carries a 5 × 18 mm, 90 mm2 (92 mm2 with tapered chamber inlets) surface area that can contain up to 1-2 × 104 adherent structural lung cells and can be utilized for close contact co-culture studies of different lung cell types, including airway epithelial cells, fibroblasts, smooth muscle cells, and endothelial cells. The parallel bi-chambered design of the chip allows for epithelial cells to be cultured at the air-liquid interface (ALI) and differentiation into a dense, multi-layered, pseudostratified epithelium under biological flow rates. This millifluidic airway-on-chip advances the field by providing a readily reproducible, easily adjustable, and cost-effective large-scale fluidic 3D airway cell culture platform.

Licorice and dried ginger decoction inhibits inflammation and alleviates mitochondrial dysfunction in chronic obstructive pulmonary disease by targeting siglec-1

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease. Licorice and dried ginger decoction (LGD) is traditional Chinese medicine prescription with multiple effects. Glycyrrhetinic acid (GA) is the main bioactive components of LGD, which has been proven to have a relieving effect on various inflammatory diseases. Siglec-1 is a cell surface sialoadhesin and has been confirmed to be overexpressed in COPD and facilitate inflammatory reaction. This study is aimed to probe the interaction between LGD, GA, and siglec-1.

METHODS

Cigarette smoke (CS) combined with lipopolysaccharide (LPS) treatment was utilized to construct a COPD rat model. Cigarette smoke extract (CSE) was utilized to induce alveolar macrophage NR8383 to construct a COPD cell model. HE staining was applied for measuring histopathological changes of COPD rats. Enzyme-linked immunosorbent assay (ELISA), reverse transcription real-time polymerase chain reaction (RT-qPCR), and western blot were applied for testing the concentrations and expressions of proinflammatory factors. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS) analysis was utilized to determine the combination between siglec-1 and GA. JC-1 assay was utilized to evaluate mitochondrial function. Reactive oxygen species (ROS) production was tested by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining.

RESULTS

LGD treatment notably alleviated lung injury and inflammatory response in COPD rats. In CSE-induced cells, LGD treatment suppressed the contents of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8. Sialic-acid-binding Ig-like lectin 1 (Siglec-1) expression induced by CS was decreased after LGD treatment. Furthermore, we proved that GA could target siglec-1 to regulate the inflammatory response in COPD rats and cells. Additionally, GA could reduce ROS production and alleviate mitochondrial dysfunction to suppress COPD progression.

CONCLUSION

LGD inhibits inflammation and alleviates mitochondrial dysfunction in COPD by targeting siglec-1.

Optimization of chemical transfection in airway epithelial cell lines

BACKGROUND

Chemical transfection is a widely employed technique in airway epithelium research, enabling the study of gene expression changes and effects. Additionally, it has been explored for its potential application in delivering gene therapies. Here, we characterize the transfection efficiency of EX-EGFP-Lv105, an EGFP-expressing plasmid into three cell lines commonly used to model the airway epithelium (1HAEo-, 16HBE14o-, and NCI-H292).

RESULTS

We used six common and/or commercially available reagents with varying chemical compositions: Lipofectamine 3000 (L3000), FuGENE HD, ViaFect, jetOPTIMUS, EndoFectin, and calcium phosphate. Using L3000, 1HAEo- exhibited the highest transfection efficiency compared to 16HBE14o- and NCI-H292 (1HAEo-: 76.1 ± 3.2%, 16HBE14o-: 35.5 ± 1.2%, NCI-H292: 28.9 ± 2.23%). L3000 yielded the greatest transfection efficiency with the lowest impact on cellular viability, normalized to control, with a 11.3 ± 0.16% reduction in 1HAEo-, 16.3 ± 0.08% reduction in 16HBE14o-, and 17.5 ± 0.09% reduction in NCI-H292 at 48-hour post-transfection. However, jetOPTIMUS had a similar transfection efficiency in 1HAEo- (90.7 ± 4.2%, p = 0.94), but had significantly reduced cellular viability of 37.4 ± 0.11% (p < 0.0001) compared to L3000. In 16HBE14o-, jetOPTIMUS yielded a significantly higher transfection efficiency compared to L3000 (64.6 ± 3.2%, p < 0.0001) but significantly reduced viability of 33.4 ± 0.09% (p < 0.0001) compared to L3000. In NCI-H292, jetOPTIMUS yielded a lower transfection efficiency (22.6 ± 1.2%) with a significant reduction in viability (28.3 ± 0.9%, p < 0.0001). Other reagents varied significantly in their efficiency and impact on cellular viability in other cell lines. Changing the transfection mixture-containing medium at 6-hour post-transfection did not improve transfection efficiency or viability. However, pre-treatment of cell cultures with two rinses of 0.25% trypsin-EDTA improved transfection efficiency in 1HAEo- (85.2 ± 1.1% vs. 71.3 ± 1.0%, p = 0.004) and 16HBE14o- (62.6 ± 4.3 vs. 35.5 ± 1.2, p = 0.003).

CONCLUSIONS

Transfection efficiencies can differ based on airway epithelial cell line, reagents, and optimization techniques used. Consideration and optimization of cell line and transfection conditions may be useful for improving nonviral genetic techniques in vitro.

Airway microbiota dysbiosis and metabolic disorder in ozone and PM2.5 co-exposure induced lung inflammatory injury in mice

Co-exposure to ground-level ozone (O3) and fine particles (PM2.5, ≤ 2.5 µm in diameter) has become a primary scenario for air pollution exposure of urbanites in China. Recent studies have suggested a synergistic effect of PM2.5 and O3 on induction of lung inflammatory injury. However, the underlying mechanisms for respiratory toxicity induced by this co-exposure have not been adequately elucidated. In this study, a realistic exposure was based to set up the co-exposure condition of an animal model. Specifically, eighty male C57BL/6 mice (10 months old) were randomly divided into four groups: control, O3, PM2.5 and co-exposure (O3 + PM2.5). Mice in the co-exposure group breathed O3 and orally inhaled PM2.5 suspension. The scenario for O3 exposure was 0.6 ppm, 4 h/d, for 30 consecutive days while that for PM2.5 exposure was oral inhalation of PM2.5 suspension (5.6 mg/kg bw) once every other day and 4 h prior to O3 exposure. After last exposure, bronchoalveolar lavage fluids (BALF) were collected for inflammatory biomarker measurement, 16S rRNA sequencing and metabolite profiling. Lung tissues were processed for histological examination. The results demonstrated that co-exposure to O3 and PM2.5 exacerbated the pathological changes and inflammatory response induced by O3 or PM2.5. Further studies revealed that co-exposure to O3 and PM2.5 increased the abundance of Prevotella in the airways and caused more severe metabolic disorders compared to O3 or PM2.5 exposure. Spearman correlation analysis demonstrated correlations among airway microbiota dysbiosis, metabolic disorder, inflammation, and pathological alterations induced by co-exposure to O3 and PM2.5. In summary, co-exposure to O3 and PM2.5 worsens airway inflammatory injury, possibly through interrelated airway microbiota dysbiosis and metabolic disorder.

The epithelial barrier theory and its associated diseases

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide. It attributes their onset to a functionally impaired epithelial barrier triggered by the toxicity of the exposed substances, associated with microbial dysbiosis, immune system activation, and inflammation. Diseases encompassed by the epithelial barrier theory share common features such as an increased prevalence after the 1960s or 2000s that cannot (solely) be accounted for by the emergence of improved diagnostic methods. Other common traits include epithelial barrier defects, microbial dysbiosis with loss of commensals and colonization of opportunistic pathogens, and circulating inflammatory cells and cytokines. In addition, practically unrelated diseases that fulfill these criteria have started to emerge as multimorbidities during the last decades. Here, we provide a comprehensive overview of diseases encompassed by the epithelial barrier theory and discuss evidence and similarities for their epidemiology, genetic susceptibility, epithelial barrier dysfunction, microbial dysbiosis, and tissue inflammation.

Plasma nicotine and its metabolite as biomarkers of tobacco exposure and their relevance to pulmonary nodule

Aim: Explore the optimal cut-off values for plasma nicotine and its metabolites in assessing smoking status and quantify the association between individual tobacco exposure and pulmonary nodules (PNs).Materials & methods: A total of 2245 plasma samples were included for the determination of nicotine (Nic), cotinine (Cot) and trans-3'-hydroxycotinine (OHCot) concentrations. The receiver operating characteristic curve was used to determine the optimal biomarkers reflecting smoking status. Binary logistic regression, restricted cubic spline and generalized linear model were used to analyze the association of nicotine and its metabolites with PNs. Quantile g-computation was used to investigate the mixed effects between them.Results: Cot was found to be the best biomarker of self-reported active-passive smoking, with optimal thresholds of 9.06 and 1.26 ng/ml, respectively. Except for OHCot, increased concentrations of Cot, Nic, total nicotine equivalent (TNE2) and TNE3 were significantly positively associated with the risk of PNs, whereas nicotine metabolite ratio presented a negative association. The mixed effects of OHCot, Cot and Nic were associated with PNs, with an odds ratio of 1.17 and a 95% CI of 1.05-1.30.Conclusion: Nicotine and its metabolites as potential biomarkers of tobacco exposure were significantly associated with PNs.

Association between frailty status and risk of chronic lung disease: an analysis based on two national prospective cohorts

BACKGROUND

The association between the frailty index (FI) and the risk of chronic lung diseases (CLDs) remains unexplored, warranting further research.

METHODS AND MATERIALS

This study investigated the relationship between FI and CLD risk using data from the China Health and Retirement Longitudinal Study (CHARLS) and English Longitudinal Study of Ageing (ELSA), comprising a combined sample of 9642 individuals. Propensity score weighting was used to ensure similar distribution of covariates across FI groups. The Wilcoxon rank-sum test was used to analyze differences in FI scores between groups with and without CLD. Kaplan-Meier curves and Cox regression analysis were employed to explore the association between frailty status and CLD incidence, with sensitivity analyses conducted for validation.

RESULTS

Higher FI scores were significantly associated with increased CLD risk in both cohorts (p < .05). Kaplan-Meier survival and Cox regression analyses indicated that frail individuals have a significantly elevated risk of CLD compared to robust individuals, particularly in certain subgroups (e.g., female) within the CHARLS cohort (p < .05). The ELSA cohort yielded similar results (p < .05), affirming FI as a strong predictor of CLD. Additional risk factors identified included age, smoking, and unmarried status (p < .05). Frail individuals consistently exhibited the highest risk in both cohorts (CHARLS HR = 1.54, p = .003; ELSA HR = 6.64, p < .001). The sensitivity analysis did not substantially alter the significant associations.

CONCLUSION

These findings emphasize the critical role of frailty in the development of CLD, suggesting that targeted interventions could reduce CLD risk.

Modulation of the Respiratory Epithelium Physiology by Flavonoids-Insights from 16HBEσcell Model

Extensive evidence indicates that the compromise of airway epithelial barrier function is closely linked to the development of various diseases, posing a significant concern for global mortality and morbidity. Flavonoids, natural bioactive compounds, renowned for their antioxidant and anti-inflammatory properties, have been used for centuries to prevent and treat numerous ailments. Lately, a growing body of evidence suggests that flavonoids can enhance the integrity of the airway epithelial barrier. The objective of this study was to investigate the impact of selected flavonoids representing different subclasses, such as kaempferol (flavonol), luteolin (flavone), and naringenin (flavanone), on transepithelial electrical resistance (TEER), ionic currents, cells migration, and proliferation of a human bronchial epithelial cell line (16HBE14σ). To investigate the effect of selected flavonoids, MTT assay, trypan blue staining, and wound healing were assessed. Additionally, transepithelial resistance and Ussing chamber measurements were applied to investigate the impact of the flavonoids on the electrical properties of the epithelial barrier. This study showed that kaempferol, luteolin, and naringenin at micromolar concentrations were not cytotoxic to 16HBE14σ cells. Indeed, in MTT tests, a statistically significant change in cell metabolic activity for luteolin and naringenin was observed. However, our experiments showed that naringenin did not affect the proliferation of 16HBE14σ cells, while the effect of kaempferol and luteolin was inhibitory. Moreover, transepithelial electrical resistance measurements have shown that all of the flavonoids used in this study improved the epithelial integrity with the slightest effect of kaempferol and the significant impact of naringenin and luteolin. Finally, our observations suggest that luteolin increases the Cl- transport through cystic fibrosis transmembrane conductance regulator (CFTR) channel. Our findings reveal that flavonoids representing different subclasses exert distinct effects in the employed cellular model despite their similar chemical structures. In summary, our study sheds new light on the diverse effects of selected flavonoids on airway epithelial barrier function, underscoring the importance of further exploration into their potential therapeutic applications in respiratory health.

Alterations in the molecular regulation of mitochondrial metabolism in human alveolar epithelial cells in response to cigarette- and heated tobacco product emissions

Mitochondrial abnormalities in lung epithelial cells have been associated with chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke (CS) can induce alterations in the molecular pathways regulating mitochondrial function in lung epithelial cells. Recently, heated tobacco products (HTPs) have been marketed as harm reduction products compared with regular cigarettes. However, the effects of HTP emissions on human alveolar epithelial cell metabolism and on the molecular mechanisms regulating mitochondrial content and function are unclear. In this study, human alveolar epithelial cells (A549) were exposed to cigarette or HTP emissions in the form of liquid extracts. The oxygen consumption rate of differently exposed cells was measured, and mRNA and protein abundancy of key molecules involved in the molecular regulation of mitochondrial metabolism were assessed. Furthermore, we used a mitophagy detection probe to visualize mitochondrial breakdown over time in response to the extracts. Both types of extracts induced increases in basal-, maximal- and spare respiratory capacity, as well as in cellular ATP production. Moreover, we observed alterations in the abundancy of regulatory molecules controlling mitochondrial biogenesis and mitophagy. Mitophagy was not significantly altered in response to the extracts, as no significant differences compared to vehicle-treated cells were observed.

Exosomal miR-129-2-3p promotes airway epithelial barrier disruption in PM2.5-aggravated asthma

Particulate matter 2.5 (PM2.5) exposure is intricately linked to asthma exacerbations. Damage to the airway epithelial barrier function serves as an initiating factor for asthma attacks and worsening symptoms. In recent years, numerous exosomal microRNAs (miRNAs) have emerged as potential biomarkers for diagnosing asthma. However, the mechanisms by which PM2.5-induced exosomes exacerbate asthma remain unclear. This study aims to investigate the role of exosomal miR-129-2-3p in regulating airway epithelial cell barrier function, its potential targets, and signaling pathways involved in PM2.5-induced aggravation of asthma. In this study, miR-129-2-3p is highly expressed in plasma exosomes from patients with asthma, mouse lung tissue and plasma exosomes, and exosomes produced by PM2.5-stimulated 16HBE cells. Moreover, the exposure level of PM2.5 is positively correlated with exosomal miR-129-2-3p in plasma in patients with asthma. As the concentration of PM2.5 increases, the synthesis of connexin (ZO-1, occludin, and E-cadherin) is gradually weakened, while the content of inflammatory factors (IL-6, IL-8, and TNF-α) is notably upregulated in PM2.5 exacerbated asthmatic mice. PM2.5-induced exosomes can decrease the level of connexin, enhance cell permeability and promote the secretion of inflammatory factors in 16HBE cells. TIAM1, a specific target gene for miR-129-2-3p, regulates the synthesis of connexin. Exosomal miR-129-2-3p exacerbates airway epithelial barrier dysfunction by targeted inhibition of the TIAM1/RAC1/PAK1 signaling pathway in PM2.5 aggravated asthma. In contrast, blocking miR-129-2-3p may be an alternative approach to therapeutic intervention in asthma.

Epithelial barrier theory in the context of nutrition and environmental exposure in athletes

Exposure to toxic substances, introduced into our daily lives during industrialization and modernization, can disrupt the epithelial barriers in the skin, respiratory, and gastrointestinal systems, leading to microbial dysbiosis and inflammation. Athletes and physically active individuals are at increased risk of exposure to agents that damage the epithelial barriers and microbiome, and their extreme physical exercise exerts stress on many organs, resulting in tissue damage and inflammation. Epithelial barrier-damaging substances include surfactants and enzymes in cleaning products, laundry and dishwasher detergents, chlorine in swimming pools, microplastics, air pollutants such as ozone, particulate matter, and diesel exhaust. Athletes' high-calorie diet often relies on processed foods that may contain food emulsifiers and other additives that may cause epithelial barrier dysfunction and microbial dysbiosis. The type of the material used in the sport equipment and clothing and their extensive exposure may increase the inflammatory effects. Excessive travel-related stress, sleep disturbances and different food and microbe exposure may represent additional factors. Here, we review the detrimental impact of toxic agents on epithelial barriers and microbiome; bring a new perspective on the factors affecting the health and performance of athletes and physically active individuals.

Mitochondrial dynamics in pulmonary disease: Implications for the potential therapeutics

Mitochondria are dynamic organelles that continuously undergo fusion/fission to maintain normal cell physiological activities and energy metabolism. When mitochondrial dynamics is unbalanced, mitochondrial homeostasis is broken, thus damaging mitochondrial function. Accumulating evidence demonstrates that impairment in mitochondrial dynamics leads to lung tissue injury and pulmonary disease progression in a variety of disease models, including inflammatory responses, apoptosis, and barrier breakdown, and that the role of mitochondrial dynamics varies among pulmonary diseases. These findings suggest that modulation of mitochondrial dynamics may be considered as a valid therapeutic strategy in pulmonary diseases. In this review, we discuss the current evidence on the role of mitochondrial dynamics in pulmonary diseases, with a particular focus on its underlying mechanisms in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), lung cancer and bronchopulmonary dysplasia (BPD), and outline effective drugs targeting mitochondrial dynamics-related proteins, highlighting the great potential of targeting mitochondrial dynamics in the treatment of pulmonary disease.

Oridonin alleviates cigarette smoke-induced nasal polyp formation by promoting autophagy

Previous studies have indicated that oridonin is a promising candidate for therapeutic intervention in a range of inflammatory diseases. The objective of this study was to investigate the protective mechanism of oridonin in chronic rhinosinusitis with nasal polyp (CRSwNP). In nasal polyp (NP) mice model, cigarette smoke (CS) induced polypoid changes compared to previous modeling methods. Compared with CS-treated mice, oridonin reduced polypoid changes, goblet cell count, and promoted the expression of tight junction proteins (ZO-1, occludin, claudin-1) and production of autophagosomes. Following treatment with oridonin, the levels of OVA-specific IgE, IL-6, IFN-γ, IL-5, IL-13 and IL-17A in serum were observed to decrease; the levels of TGF-β1, matrix metalloproteinase 2 (MMP2), MMP7, MMP9 and MMP12 levels in nasal lavage fluid were reduced, while tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were increased. Furthermore, the aforementioned alterations in the mouse model were reversed by 3-methyladenine (3-MA), an autophagy inhibitor. In vitro, cigarette smoke extract (CSE) was observed to decrease the expression of tight junction proteins, the production of autophagosomes, and to reduce the expression of LC3-II and Beclin-1, accompanied by an increase in P62 expression. In addition, oridonin was observed to reverse CSE-induced epithelial barrier damage, and was associated with autophagy and the PI3K/AKT/mTOR pathway. In conclusion, oridonin was demonstrated to improve the damage of the nasal epithelial barrier induced by CS through the promotion of autophagy, which may represent a novel therapeutic option for the treatment of CRSwNP.

Immune system benefits of pulmonary rehabilitation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by pulmonary and systemic inflammation. Inflammatory mediators show relationships with shortness of breath, exercise intolerance and health related quality of life. Pulmonary rehabilitation (PR), a comprehensive education and exercise training programme, is the most effective therapy for COPD and is associated with reduced exacerbation and hospitalization rates and increased survival. Exercise training, the primary physiological intervention within PR, is known to exert a beneficial anti-inflammatory effect in health and chronic diseases. The question of this review article is whether exercise training can also make such a beneficial anti-inflammatory effect in COPD. Experimental studies using smoke exposure mice models suggest that the response of the immune system to exercise training is favourably anti-inflammatory. However, the evidence about the response of most known inflammatory mediators (C-reactive protein, tumour necrosis factor α, interleukin 6, interleukin 10) to exercise training in COPD patients is inconsistent, making it difficult to conclude whether regular exercise training has an anti-inflammatory effect in COPD. It is also unclear whether COPD patients with more persistent inflammation are a subgroup that would benefit more from hypothesized immunomodulatory effects of exercise training (i.e., personalized treatment). Nevertheless, it seems that PR combined with maintenance exercise training (i.e., lifestyle change) might be more beneficial in controlling inflammation and slowing disease progress in COPD patients, specifically in those with early stages of disease.

LncRNA MALAT1 regulates cigarette smoke induced airway inflammation by modulating miR-30a-5p/JNK signaling pathway

Chronic airway inflammation induced by cigarette smoke (CS) plays an essential role in the pathogenesis of chronic obstructive pulmonary disease (COPD). MALAT1 is involved in a variety of inflammatory disorders. However, studies focusing on the interaction between MALAT1 and CS-induced airway inflammation remain unknown. The present study investigated the effects and mechanisms of MALAT1 in CS-induced airway inflammation in the pathogenesis of COPD. RT-qPCR was employed to determine the mRNA levels of MALAT1, miR-30a-5p and inflammatory cytokines. Protein concentrations of IL-1β and IL-6 in cell culture supernatant and mouse bronchoalveolar lavage fluid (BALF) were assessed by ELISA assay kits. Dual-luciferase reporter assay was conducted to verify the interaction between MALAT1 and miR-30a-5p. The protein expression of JNK and p-JNK was determined by western blot (WB). MALAT1 was highly expressed in cigarette smoke extract (CSE)-treated human bronchial epithelial cells (HBECs) and COPD mice lung tissues. Knockdown of MALAT1 significantly alleviate CS-induced inflammatory response. MALAT1 directly interacted with miR-30a-5p and knockdown of miR-30a-5p significantly inhibit the protective effects of MALAT1 silencing after CS exposure. Additionally, our results showed that miR-30a-5p could regulate inflammation via modulating the activation of JNK signaling pathway. Moreover, our results demonstrated MALAT1 could activate JNK signaling pathway by sponging miR-30a-5p. Our results demonstrated MALAT1 promotes CS-induced airway inflammation by inhibiting the activation of JNK signaling pathway via sponging miR-30a-5p.

Air-Pollution-Mediated Microbial Dysbiosis in Health and Disease: Lung-Gut Axis and Beyond

Growing evidence suggests physiological and pathological functions of lung and gut microbiomes in various pathologies. Epidemiological and experimental data associate air pollution exposure with host microbial dysbiosis in the lungs and gut. Air pollution through increased reactive oxygen species generation, the disruption of epithelial barrier integrity, and systemic inflammation modulates microbial imbalance. Microbiome balance is crucial in regulating inflammation and metabolic pathways to maintain health. Microbiome dysbiosis is proposed as a potential mechanism for the air-pollution-induced modulation of pulmonary and systemic disorders. Microbiome-based therapeutic approaches are increasingly gaining attention and could have added value in promoting lung health. This review summarizes and discusses air-pollution-mediated microbiome alterations in the lungs and gut in humans and mice and elaborates on their role in health and disease. We discuss and summarize the current literature, highlight important mechanisms that lead to microbial dysbiosis, and elaborate on pathways that potentially link lung and lung microbiomes in the context of environmental exposures. Finally, we discuss the lung-liver-gut axis and its potential pathophysiological implications in air-pollution-mediated pathologies through microbial dysbiosis.

REV-ERBα agonist SR10067 attenuates Th2 cytokine-mediated barrier dysfunction in human bronchial epithelial cells

Allergens and Th2 cytokines affect the homeostatic environment in the airways, leading to increased mucus production by goblet cells associated with altered adherens junctional complex (AJC) and tight junction (TJ) proteins responsible for maintaining epithelial barrier function. Circadian clock-dependent regulatory mechanisms such as inflammation and epithelial barrier function are gaining more attention due to their therapeutic potential against allergic inflammatory lung diseases. Currently, there are no studies to support whether REV-ERBα activation can attenuate Th2 cytokine-induced epithelial barrier dysfunction in human bronchial epithelial cells. We hypothesized that Th2 cytokine-induced epithelial barrier dysfunction may be protected by activating REV-ERBα. Treatment with Th2 cytokines or HDM significantly reduced the cell impedance, as confirmed by transepithelial electrical resistance (TEER). However, pre-treatment with SR10067 attenuated Th2 cytokine-induced barrier dysfunction, such as decreased permeability, improved TEER, localization of AJC and TJ proteins, and mRNA and protein levels of selected epithelial barrier and circadian clock targets. Overall, we showed for the first time that REV-ERBα activation regulates altered epithelial barrier function that may have direct implications for the treatment of asthma and other allergic diseases.

Understanding how methyltransferase-like 3 functions in lung diseases: From pathogenesis to clinical application

Lung diseases have complex pathogenesis and treatment challenges, showing an obvious increase in the rate of diagnosis and death every year. Therefore, elucidating the mechanism for their pathogenesis and treatment ineffective from novel views is essential and urgent. Methyltransferase-like 3 (METTL3) is a novel post-transcriptional regulator for gene expression that has been implicated in regulating lung diseases, including that observed in chronic conditions such as pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), and chronic obstructive pulmonary disease (COPD), as well as acute conditions such as pneumonia, severe acute respiratory syndrome coronavirus 2 infection, and sepsis-induced acute respiratory distress syndrome. Notably, a comprehensive summary and analysis of findings from these studies might help understand lung diseases from the novel view of METTL3-regulated mechanism, however, such a review is still lacking. Therefore, this review aims to bridge such shortage by summarising the roles of METTL3 in lung diseases, establishing their interrelationships, and elucidating the potential applications of METTL3 regarding diagnosis, treatment, and prognosis. The analysis collectively suggests METTL3 is contributable to the onset and progression of these lung diseases, thereby prospecting METTL3 as a valuable biomarker for their diagnosis, treatment, and prognosis. In conclusion, this review offers elucidation into the correlation between METTL3 and lung diseases in both research and clinical settings and highlights potential avenues for exploring the roles of METTL3 in the respiratory system.

Release of IL-1β and IL-18 in human primary bronchial epithelial cells exposed to cigarette smoke is independent of NLRP3

Cigarette smoke (CS) is a major risk factor for chronic lung diseases and promotes activation of pattern recognition receptors in the bronchial epithelium. NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a pattern recognition receptor whose activation leads to caspase-1 cleavage, maturation/release of IL-1β and IL-18, and eventually pyroptosis. Whether the NLRP3 inflammasome participates in CS-induced inflammation in bronchial epithelial cells is still unclear. Herein, we evaluated the involvement of NLRP3 in CS-induced inflammatory responses in human primary bronchial epithelial cells. To this purpose, human primary bronchial epithelial cells were stimulated with CS extracts (CSE) and lytic cell death, caspase activation (-1, -8, -3/7), cytokine release (IL-1β, IL-18, and IL-8), NLRP3, pro-IL-1β/pro-IL-18 mRNA, and protein expression were measured. The impact of inhibitors of NLRP3 (MCC950), caspases, and the effect of the antioxidant N-acetyl cysteine were evaluated. We found that CSE increased pro-IL-1β expression and induced activation of caspase-1 and release of IL-1β and IL-18. These events were independent of NLRP3 and we found that NLRP3 was not expressed. N-acetyl cysteine reverted CSE-induced caspase-1 activation. Overall, our findings support that the bronchial epithelium may play a central role in the release of IL-1 family cytokines independently of NLRP3 in the lungs of smokers.

Diagnostic Challenges and Pathogenetic Differences in Biomass-Smoke-Induced versus Tobacco-Smoke-Induced COPD: A Comparative Review

Background: Chronic Obstructive Pulmonary Disease (COPD) is a major global health challenge, primarily driven by exposures to tobacco smoke and biomass smoke. While Tobacco-Smoke-Induced COPD (TSCOPD) has been extensively studied, the diagnostic challenges and distinct pathogenesis of Biomass-Smoke-Induced COPD (BSCOPD), particularly in low- and middle-income countries, remain underexplored. Objective: To explore the differences in clinical manifestations, pulmonary function, and inflammatory profiles between BSCOPD and TSCOPD and highlight the diagnostic complexities of BSCOPD. Methods: This review analyzes the current literature comparing BSCOPD with TSCOPD, focusing on distinctive pathophysiological mechanisms, inflammatory markers, and oxidative stress processes. Results: BSCOPD presents differences in clinical presentation, with less emphysema, smaller airway damage, and higher rates of pulmonary hypertension compared to TSCOPD. BSCOPD is also characterized by bronchial hyperresponsiveness and significant hypoxemia, unlike TSCOPD, which exhibits severe airflow obstruction and emphysema. Additionally, the inflammatory profile of BSCOPD includes distinct mucous hypersecretion and airway remodeling. Conclusions: The unique genetic, epigenetic, and oxidative stress mechanisms involved in BSCOPD complicate its diagnosis and management. Biomass smoke's underrecognized impact on accelerated lung aging and exacerbation mechanisms emphasizes the need for targeted research to refine diagnostic criteria and management strategies for BSCOPD. Future directions: Further research should focus on identifying specific biomarkers and molecular pathways to enhance early diagnosis and improve clinical outcomes in populations exposed to biomass smoke.

Developmental PFOS exposure alters lung inflammation and barrier integrity in juvenile mice

Emerging epidemiological evidence indicates perfluorooctane sulfonic acid (PFOS) is increasingly associated with asthma and respiratory viral infections. Animal studies suggest PFOS disrupts lung development and immuno-inflammatory responses, but little is known about the potential consequences on respiratory health and disease risk. Importantly, PFOS exposure during the critical stages of lung development may increase disease risk later in life. Thus, we hypothesized that developmental PFOS exposure will affect lung inflammation and alveolar/airway development in a sex-dependent manner. To address this knowledge gap, timed pregnant Balb/cJ dams were orally dosed with a PFOS (1.0 or 2.0 mg/kg/d) injected mealworm or a vehicle control daily from gestational day (GD) 0.5 to postnatal day (PND) 21, and offspring were sacrificed at PND 22-23. PFOS-exposed male offspring displayed increased alveolar septa thickness. Occludin was also downregulated in the lungs after PFOS exposure in mice, indicative of barrier dysfunction. BALF macrophages were significantly elevated at 2.0 mg/kg/d PFOS in both sexes compared with vehicles, whereas BALF cytokines (TNF-α, IL-6, KC, MIP-1α, MIP-1β, and MCP-1) were suppressed in PFOS-exposed male offspring compared with vehicle controls. Multiplex nucleic acid hybridization assay showed male-specific downregulation of cytokine gene expression in PFOS-exposed mice compared with vehicle mice. Overall, these results demonstrate PFOS exposure exhibits male-specific adverse effects on lung development and inflammation in juvenile offspring, possibly predisposing them to later-in-life respiratory disease. Further research is required to elucidate the mechanisms underlying the sex-differentiated pulmonary toxicity of PFOS.

A novel in vitro high-content imaging assay for the prediction of drug-induced lung toxicity

The development of inhaled drugs for respiratory diseases is frequently impacted by lung pathology in non-clinical safety studies. To enable design of novel candidate drugs with the right safety profile, predictive in vitro lung toxicity assays are required that can be applied during drug discovery for early hazard identification and mitigation. Here, we describe a novel high-content imaging-based screening assay that allows for quantification of the tight junction protein occludin in A549 cells, as a model for lung epithelial barrier integrity. We assessed a set of compounds with a known lung safety profile, defined by clinical safety or non-clinical in vivo toxicology data, and were able to correctly identify 9 of 10 compounds with a respiratory safety risk and 9 of 9 compounds without a respiratory safety risk (90% sensitivity, 100% specificity). The assay was sensitive at relevant compound concentrations to influence medicinal chemistry optimization programs and, with an accessible cell model in a 96-well plate format, short protocol and application of automated imaging analysis algorithms, this assay can be readily integrated in routine discovery safety screening to identify and mitigate respiratory toxicity early during drug discovery. Interestingly, when we applied physiologically-based pharmacokinetic (PBPK) modelling to predict epithelial lining fluid exposures of the respiratory tract after inhalation, we found a robust correlation between in vitro occludin assay data and lung pathology in vivo, suggesting the assay can inform translational risk assessment for inhaled small molecules.

In vitro evidence of antioxidant and anti-inflammatory effects of a new nutraceutical formulation explains benefits in a clinical setting of COPD patients

Background and Aim: Increased oxidative stress within the airways is associated to epithelial damage and amplification of inflammatory responses that in turn contribute to Chronic Obstructive Pulmonary Disease (COPD) progression. This study was aimed to identify whether a new formulation of N-acetylcisteine (NAC), carnitine, curcumin and B2 vitamin could counteract oxidative stress and downstream pro-inflammatory events promoted by cigarette smoke extract (CSE) exposure in primary bronchial epithelial cells (PBEC), both submerged/undifferentiated (S-PBEC) and cultured at the air-liquid interface (ALI-PBEC). Methods: PBEC were exposed to CSE with/without the new formulation or NAC alone and ROS production, IL-8 and IL-6 gene expression and protein release were evaluated. Results: CSE increased ROS, IL-8 and IL-6 gene expression and protein release and the new formulation counteracted these effects. NAC alone was not effective on IL-8 and IL-6 release. The effects of a similar nutraceutical formulation were evaluated in COPD patients treated for six months. The results showed that the treatment reduced the concentration of IL-8 in nasal wash and improved quality of life. Conclusion: The tested formulation, exerting antioxidant and anti-inflammatory effects, can preserve airway epithelial homeostasis and improve clinical symptoms in COPD.

Dynamics for High-Sensitivity Detection of Free Radicals in Primary Bronchial Epithelial Cells upon Stimulation with Cigarette Smoke Extract

Chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide, is caused by chronic exposure to toxic particles and gases, such as cigarette smoke. Free radicals, which are produced during a stress response to toxic particles, play a crucial role in disease progression. Measuring these radicals is difficult since the complex mixture of chemicals within cigarette smoke interferes with radical detection. We used a new quantum sensing technique called relaxometry to measure free radicals with nanoscale resolution on cells from COPD patients and healthy controls exposed to cigarette smoke extract (CSE) or control medium. Epithelial cells from COPD patients display a higher free radical load than those from healthy donors and are more vulnerable to CSE. We show that epithelial cells of COPD patients are more susceptible to the damaging effects of cigarette smoke, leading to increased release of free radicals.

Pre-frailty after blood or marrow transplantation and the risk of subsequent mortality

We examined the prevalence, risk factors, and association between pre-frailty and subsequent mortality after blood or marrow transplantation (BMT). Study participants were drawn from the BMT Survivor Study (BMTSS) and included 3346 individuals who underwent BMT between 1974 and 2014 at one of three transplant centers and survived ≥2 years post-BMT. Participants completed the BMTSS survey at a median of 9 years from BMT and were followed for subsequent mortality for a median of 5 years after survey completion. Closest-age and same-sex biological siblings also completed the survey. Previously published self-reported indices (exhaustion, weakness, low energy expenditure, slowness, unintentional weight loss) classified participants as non-frail (0-1 indices) or pre-frail (2 indices). National Death Index was used to determine vital status and cause of death. Overall, 626 (18.7%) BMT survivors were pre-frail. BMT survivors had a 3.2-fold higher odds of being pre-frail (95% CI = 1.9-5.3) compared to siblings. Compared to non-frail survivors, pre-frail survivors had higher hazards of all-cause mortality (adjusted hazard ratio [aHR] = 1.6, 95% CI = 1.4-2.0). Female sex, pre-BMT radiation, smoking, lack of exercise, anxiety, and severe/life-threatening chronic health conditions were associated with pre-frailty. The novel association between pre-frailty and subsequent mortality provides evidence for interventions as pre-frail individuals may transition back to their robust state.

Overexpression of USP8 inhibits inflammation and ferroptosis in chronic obstructive pulmonary disease by regulating the OTUB1/SLC7A11 signaling pathway

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a familiar disease, and owns high morbidity and mortality, which critically damages the health of patients. Ubiquitin-specific peptidase 8 (USP8) is a pivotal protein to join in the regulation of some diseases. In a previous report, it was determined that USP8 expression is down-regulated in LPS-treated BEAS-2B cells, and USP8 restrains inflammatory response and accelerates cell viability. However, the regulatory roles of USP8 on ferroptosis in COPD are rarely reported, and the associated molecular mechanisms keep vague.

OBJECTIVE

To investigate the regulatory functions of USP8 in COPD progression.

MATERIAL AND METHODS

The lung functions were measured through the Buxco Fine Pointe Series Whole Body Plethysmography (WBP). The Fe level was tested through the Fe assay kit. The protein expressions were assessed through western blot. The levels of tumor necrosis -factor-α, interleukin 6, and interleukin 8 were evaluated through enzyme-linked immunosorbent serologic assay. Cell viability was tested through CCK-8 assay.

RESULTS

In this work, it was discovered that overexpression of USP8 improved lung function in COPD mice. In addition, overexpression of USP8 repressed ferroptosis by regulating glutathione peroxidase 4 and acyl-CoA synthetase long-chain family 4 expressions in COPD mice. Overexpression of USP8 suppressed inflammation in COPD mice. Furthermore, overexpression of USP8 suppressed ferroptosis in COPD cell model. At last, it was verified that overexpression of USP8 accelerated ubiquitin aldehyde-binding protein 1 (OTUB1)/solute carrier family 7 member 11 (SLC7A11) pathway.

CONCLUSION

This study manifested that overexpression of USP8 restrained inflammation and ferroptosis in COPD by regulating the OTUB1/SLC7A11 signaling pathway. This discovery hinted that USP8 could be a potential target for COPD treatment.

Propofol modulates Nrf2/NLRP3 signaling to ameliorate cigarette smoke-induced damage in human bronchial epithelial cells

Cigarette smoke extract (CSE) is known as a significant contributor to chronic obstructive pulmonary disease (COPD). Propofol, an anesthetic agent, has been studied for its potential protective effects against lung damage. This study aimed to elucidate the protective mechanisms of propofol against CSE-induced damage in human bronchial epithelial 16HBE cells. In CSE-induced 16HBE cells treated by propofol with or without transfection of nuclear factor erythroid 2-related factor 2 (Nrf2) interference plasmids, CCK-8 assay and lactate dehydrogenase (LDH) assay evaluated cytotoxicity. TUNEL assay and Western blot appraised cell apoptosis. ELISA and relevant assay kits severally measured inflammatory and oxidative stress levels. DCFH-DA fluorescent probe detected intracellular reactive oxygen species (ROS) activity. Immunofluorescence staining and Western blot estimated pyroptosis. Also, Western blot analyzed the expression of Nrf2/NLR family pyrin domain containing 3 (NLRP3) signaling-related proteins. Propofol was found to enhance the viability, reduce LDH release, and alleviate the apoptosis, inflammatory response, oxidative stress and pyroptosis in CSE-induced 16HBE cells in a concentration-dependent manner. Meanwhile, propofol decreased NLRP3 expression while raised Nrf2 expression. Further, after Nrf2 was silenced, the impacts of propofol on Nrf2/NLRP3 signaling, LDH release, apoptosis, inflammatory response, oxidative stress and pyroptosis in CSE-exposed 16HBE cells were eliminated. Conclusively, propofol may exert protective effects against CSE-induced damage in 16HBE cells, partly through the modulation of the Nrf2/NLRP3 signaling pathway, suggesting a potential therapeutic role for propofol in CSE-induced bronchial epithelial cell damage.

Revisiting airway epithelial dysfunction and mechanisms in chronic obstructive pulmonary disease: the role of mitochondrial damage

Chronic exposure to environmental hazards causes airway epithelial dysfunction, primarily impaired physical barriers, immune dysfunction, and repair or regeneration. Impairment of airway epithelial function subsequently leads to exaggerated airway inflammation and remodeling, the main features of chronic obstructive pulmonary disease (COPD). Mitochondrial damage has been identified as one of the mechanisms of airway abnormalities in COPD, which is closely related to airway inflammation and airflow limitation. In this review, we evaluate updated evidence for airway epithelial mitochondrial damage in COPD and focus on the role of mitochondrial damage in airway epithelial dysfunction. In addition, the possible mechanism of airway epithelial dysfunction mediated by mitochondrial damage is discussed in detail, and recent strategies related to airway epithelial-targeted mitochondrial therapy are summarized. Results have shown that dysregulation of mitochondrial quality and oxidative stress may lead to airway epithelial dysfunction in COPD. This may result from mitochondrial damage as a central organelle mediating abnormalities in cellular metabolism. Mitochondrial damage mediates procellular senescence effects due to mitochondrial reactive oxygen species, which effectively exacerbate different types of programmed cell death, participate in lipid metabolism abnormalities, and ultimately promote airway epithelial dysfunction and trigger COPD airway abnormalities. These can be prevented by targeting mitochondrial damage factors and mitochondrial transfer. Thus, because mitochondrial damage is involved in COPD progression as a central factor of homeostatic imbalance in airway epithelial cells, it may be a novel target for therapeutic intervention to restore airway epithelial integrity and function in COPD.

The role of gut-lung axis in COPD: Pathogenesis, immune response, and prospective treatment

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and healthcare burden worldwide. The progression of COPD is a combination of genetic predisposition and environmental factors, primarily cigarette smoking, and the underlying mechanisms are still unknown. Intestinal microecology impacts host immunity, metabolism, and resistance to pathogenic infections, which may be involved in pulmonary disease. Moreover, substantial interaction occurs between the intestinal and respiratory immune niches. After reviewing nearly 500 articles, we found the gut-lung axis plays an important role in the development of COPD. COPD patients often have dysbiosis of the intestinal microenvironment, which can affect host immunity through a series of mechanisms, exacerbating or protecting against COPD progression. This paper summarizes how the gut-lung axis influences COPD, including the alterations of intestinal microecology, the pathological mechanisms, and the involved immune responses. Finally, we summarize the latest research advances in COPD treatment from the perspective of regulating the gut-lung axis and intestinal immunity and evaluate the potential value of the gut-lung axis in improving COPD prognosis.

[Take-home messages from the 2nd COPD 2023 Biennial of the French Society of Respiratory Diseases. Placing the patient at the center of the care pathway]

INTRODUCTION

The second COPD Biennial organized by the COPD working group of the French Society of Respiratory Diseases took place in Paris (Cochin) on 13th December 2023.

STATE OF THE ART

Major trends in 2023 were discussed; they encompassed concepts, definitions, biologics, care pathways, pulmonary rehabilitation and complex situations entailed by respiratory infections, cardiovascular comorbidities and pulmonary hypertension, and modalities of oxygen therapy and ventilation.

PERSPECTIVES

The different talks underlined major changes in COPD including the concepts of pre-COPD, etiotypes, health trajectories and new definitions of exacerbation. Recent results in biologics for COPD open the door to new pharmacological options. Assessment of current care pathways in France highlighted some causes for concern. For example, pulmonary rehabilitation is a key but insufficiently practiced element. Respiratory infections require careful assessment and treatments. Diagnosis and treatment of cardiovascular comorbidities and pulmonary hypertension are of paramount importance. As of late, oxygen therapy and ventilation modalities have evolved, and are beginning to afford more personalized options.

CONCLUSIONS

As regards COPD, a personalized approach is crucial, placing the patient at the center of the care pathway and facilitating coordination between healthcare providers.

Elevated expression of NLRP3 promotes cigarette smoke-induced airway inflammation in chronic obstructive pulmonary disease

Introduction

NOD-like receptor protein 3 (NLRP3) is implicated in chronic obstructive pulmonary disease (COPD) pathogenesis. Here, we explored the role of NLRP3 in cigarette smoke (CS)-induced airway inflammation in COPD.

Material and methods

NLRP3 expression level was assessed with the microarray data in GEO datasets and validated in serum by ELISA from a case-control cohort. Male C57BL/6J mice were randomly divided into: saline, CS, MCC950 (a specific NLRP3 inhibitor, 10 mg/kg) and CS + MCC950 (5 mg/kg and 10 mg/kg) groups (n = 5 per group). All mice were exposed to CS or air for 4 weeks. Then, broncho-alveolar lavage (BAL) fluid and lung tissues were collected for cell counting, ELISA, HE staining and RNA sequencing with validation by real-time qPCR.

Results

Compared to non-smokers, NLRP3 expression was significantly elevated in the lung tissues and sera of COPD smokers. CS remarkably induced airway inflammation in mice, characterized by an increase of inflammatory cells and proinflammatory cytokines in BAL fluid and HE inflammatory score, which were ameliorated by MCC950 treatment dose-dependently. Subsequently, 84 candidate genes were selected following RNA sequencing, and five hub genes (Mmp9, IL-1α, Cxcr2, Cxcl10, Ccr1) were then identified by PPI and MCODE analyses, which were confirmed by real-time qPCR. GO and KEGG analysis suggested that the five genes were enriched in a complicated network of inflammatory processes and signaling pathways.

Conclusions

NLRP3 expression is elevated in lungs and sera of COPD smokers. Inhibition of NLRP3 significantly attenuates CS-induced airway inflammation in mice via inactivation of multiple hub genes and their related inflammatory processes and signaling pathways.