Nitric Oxide System and Bronchial Epithelium: More Than a Barrier

Deficiency of inducible nitric oxide synthase (iNOS) enhances MC903-induced atopic dermatitis-like inflammation in mice

The production and secretion of inflammatory mediators contribute to the development of atopic dermatitis (AD). The production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) is essential for inflammation. Because of the association of iNOS with type 2 inflammation, upregulated iNOS expression in patients with AD suggests a potential pathogenic role of iNOS in AD. In addition, NO regulates keratinocyte and immune cell functions in various inflammatory dermatoses, contributing to the triggering and amplification of inflammation. To ascertain the role of iNOS in inflammation, we utilized a calcipotriol (CPT, MC903)-induced AD-like inflammation in C57BL/6J wildtype mice and iNOS knockout (iNOS KO) mice to investigate the role of iNOS in inflammation. The results showed that iNOS deficiency aggravated dermatitis in MC903-induced inflammation. The expression levels of pro-inflammatory cytokines and chemokines were dramatically elevated, accompanied by the activation of several pro-inflammatory signaling pathways. Moreover, immunofluorescence staining showed that iNOS was mainly expressed in the epidermis and iNOS deficiency significantly promoted the expression of inflammatory factors in keratinocytes. Additionally, topical application of NO donors ameliorated dermatitis symptoms in the iNOS KO mice. These results indicated that epidermal iNOS is important for the occurrence and development of AD. Our results also underscore the therapeutic potential of NO donors in the treatment of AD.

Topical application of insulin encapsulated by chitosan-modified PLGA nanoparticles to alleviate alkali burn-induced corneal neovascularization

Corneal neovascularization (CRNV) severely impairs corneal transparency and is one of the leading causes of vision loss worldwide. Drug therapy is the main approach to inhibit CRNV. Insulin (INS) has been reported to facilitate the healing of corneal injuries and suppress inflammation. However, but due to the unique physiological barriers of the eye, its bioavailability is low, limiting its therapeutic effect. In this study, we developed a chitosan-poly(lactic-co-glycolic acid)-INS nanoparticles (CPI NPs) system for INS delivery. The characterization of CPI NPs was satisfactory. Experimental results demonstrated that CPI NPs effectively inhibited the migration of vascular endothelial cells and the formation of tubular structures. Furthermore, CPI NPs markedly suppressed the neovascularization in a CRNV model without any observable side effects. Quantitative proteomics analysis indicated that INS treatment led to a reduction in FTO levels within the neovascularized cornea. Both in vitro and in vivo experiments substantiated the impact of CPI NPs on FTO protein expression and the N6-methyladenosine modification. In conclusion, this study successfully developed an effective ocular drug delivery system for the treatment of CRNV induced by alkali burns, thereby offering a novel therapeutic option for this condition.

Constructing a Prognostic Model for Non-Small-Cell Lung Cancer Risk Based on Genes Characterising the Differentiation of Myeloid-Derived Suppressor Cells

Cancer is the most common malignancy, with over 2 million new cases and nearly 1.8 million deaths worldwide annually. Non-small-cell lung cancer (NSCLC) is the predominant subtype, accounting for the majority of cases. Myeloid-derived suppressor cells (MDSCs), which originate from monocytes and typically differentiate into macrophages and granulocytes, possess potent immunosuppressive capabilities. MDSCs regulate immune responses in various pathological conditions and are strongly associated with poor prognosis in cancer patients. This study aims to elucidate the complex interplay between MDSCs, immune cells, and tumours in the NSCLC tumour microenvironment (TME). By integrating single-cell RNA sequencing (scRNA-seq) data with bulk RNA sequencing (Bulk RNA-seq) data, we identified MDSCs as the target cell population and used Monocle software (v2.22.0) to infer their developmental trajectories. We identified key genes associated with MDSCs differentiation processes and classified MDSCs into seven distinct states based on their functional roles. Furthermore, we constructed a prognostic risk model based on the impact of MDSCs differentiation on NSCLC prognosis, utilizing Elastic Net regression and multivariate Cox regression analysis of Bulk RNA-seq data. The model's performance and accuracy were validated using both internal and external validation sets. Additionally, we compared risk scores with clinical pathological features and the relationship between risk scores and key immune cells in the immune microenvironment, demonstrating the model's clinical predictive value. We also explored how prognostic genes contribute to poor prognosis in NSCLC. Moreover, small molecule compounds targeting these prognostic genes were screened, and their anti-tumour effects were evaluated as potential therapeutic strategies for NSCLC treatment. This study not only reveals the complex regulatory mechanisms of MDSCs in the NSCLC immune microenvironment but also successfully constructs a prognostic risk model based on MDSCs differentiation states. The model demonstrates excellent clinical performance in predicting patient prognosis, effectively identifying high-risk patients and providing robust support for individualized treatment and immunotherapy decisions. Through association analyses with key immune cells in the immune microenvironment and clinical pathological features, our model can assist clinicians in formulating more precise treatment plans based on patients' immune status and tumour characteristics. Furthermore, we identified small molecule compounds targeting these prognostic genes, providing novel and promising therapeutic targets for NSCLC, which could further enhance treatment efficacy and improve patients' survival quality.

Exploring the link between nutritional status and total antioxidant status in patients with severe asthma: a cross-sectional study

BACKGROUND AND OBJECTIVE

This study aimed to assess the nutritional status of individuals with severe asthma and to determine how dietary antioxidant (AO) intake influences the disease prognosis and plasma total antioxidant status (TAS).

METHODS

The study included 44 patients with severe asthma and 45 healthy participants. Anthropometric measurements, asthma control levels, scores from a validated antioxidant food consumption frequency questionnaire, 3-day food records, and demographic information were gathered from each participant. Blood samples obtained after overnight fasting were analyzed for plasma TAS and total oxidant status (TOS).

RESULTS

The mean antioxidant intake measured by the FFQ and food records, as well as plasma TAS levels, were significantly lower in the asthma group compared to the control group (p < 0.05). In the asthma group, negative correlations were found between the duration of asthma and both plasma TAS and antioxidant intake from the FFQ and food records, indicating that longer asthma duration was associated with lower antioxidant status (p < 0.05). Additionally, a positive correlation was observed between the asthma control level and the antioxidant intake from the FFQ in the case group, suggesting that better asthma control was associated with higher antioxidant intake (p < 0.05).

CONCLUSION

Plasma TAS levels in patients with severe asthma were significantly lower than in healthy individuals. Higher dietary antioxidant intake was positively associated with plasma TAS and may contribute to improved asthma control. These findings suggest that increasing dietary antioxidant intake could be beneficial in the management of severe asthma.

CLINICAL TRIAL NUMBER

Not applicable.

The Direct and Indirect Role of IgE on Airway Epithelium in Asthma

Asthma is a chronic airway inflammatory disorder, affecting over 350 million people worldwide, with allergic asthma being the most common form of the disease. Allergic asthma is characterized by a type 2 (T2) inflammatory response triggered by numerous allergens beginning in the airway epithelium, which acts as a physical barrier to allergens as well as other external irritants including infectious agents, and atmospheric pollutants. T2 inflammation is propagated by several key cell types including T helper 2 (Th2) cells, eosinophils, mast cells, and B cells. Immunoglobulin E (IgE), produced by B cells, is a key molecule in allergic airway disease and plays an important role in T2 inflammation, as well as being central to remodeling processes within the airway epithelium. Blocking IgE with omalizumab has been shown to be efficacious in treating allergic asthma however, the role of IgE on airway epithelial cells is less communicated. Developing a deeper explanation of the complex network of interactions between IgE and the airway epithelium will facilitate an improved understanding of asthma pathophysiology. This review discusses the indirect and direct roles of IgE on airway epithelial cells, with a focus on allergic asthma disease.

Endogenous production of nitric oxide by iNOS in human cells restricts inflammatory activation and cholesterol/fatty acid biosynthesis

Nitric oxide (NO) is a bioactive gas that is known to control many physiological processes. In human parenchymal cells, the function of iNOS-derived NO is incompletely understood. Here, we used RNA-seq to examine the role of iNOS-derived NO in the control of gene expression in a human lung epithelial cell line treated with inflammatory cytokines. iNOS-derived NO restricted the expression of genes involved in immune signaling, including the immune-related genes CXCL9 and E-selectin that were not previously known to be inhibited by iNOS. We also determined that iNOS-derived NO inhibits the expression of genes needed for cholesterol/fatty acid biosynthesis in response to cytokine stimulation, a process not previously known to be affected by NO. These findings establish the regulation of immune activation and cholesterol/fatty acid biosynthesis as main functions of iNOS in human parenchymal cells.

Targeting Non-Eosinophilic Immunological Pathways in COPD and AECOPD: Current Insights and Therapeutic Strategies

COPD is a multifactorial illness characterized by a long-term restriction of airflow and an inflammatory reaction in the lungs. The associated emphysema leads to the breakdown of alveolar proteins and abnormal expansion of the lung air spaces. Chronic bronchitis caused by the same disease can result in increased deposition of structural proteins, narrowing of the airways, and excessive mucus secretion leading to acute exacerbation of COPD (AECOPD). The most commonly prescribed medications for it, such as glucocorticoids and bronchodilators, provide important therapeutic benefits, but they also have negative side effects, including immunosuppression and infection. Therefore, it is necessary to develop medications for the treatment of COPD that specifically target the immune system and molecular components. This review focuses on non-eosinophilic aspects of immunological modulation in COPD management. Since, existing literature extensively covers eosinophilic inflammation, this review aims to fill the gap by examining alternative immunological pathways and their therapeutic implications. The findings suggest that targeting specific immune responses may enhance treatment efficacy while minimizing adverse effects associated with traditional therapies. In summary, this review emphasizes the importance of advancing research into non-eosinophilic immunological mechanisms in COPD, prescribing for the development of novel therapies that can more effectively manage this disease.

Repeated-Dose Toxicity of Lauric Acid and Its Preventive Effect Against Tracheal Hyper-Responsiveness in Wistar Rats with Possible In Silico Molecular Targets

BACKGROUND/OBJECTIVES

Lauric acid (LA), a medium-chain fatty acid, is a promising drug for asthma treatment. This study evaluated the toxicity of repeated doses and the effect of LA on pulmonary ventilation and tracheal reactivity in asthmatic Wistar rats and identified possible molecular targets of LA action in silico.

METHODS

The rats were divided into control (CG) and LA-treated groups at 100 mg/kg (AL100G) for toxicity analysis. Pulmonary ventilation and tracheal reactivity were assessed in the control (CG), asthmatic (AG), asthmatic treated with LA at 25, 50, or 100 mg/kg (AAL25G, AAL50G, and AAL100G), and dexamethasone-treated groups (ADEXAG).

RESULTS

The results showed that LA at a dose of 100 mg/kg did not cause death or toxicity. A pulmonary ventilation analysis indicated that AG had reduced minute volume, which was prevented in AAL25G. LA at all doses prevented carbachol-induced tracheal hyper-responsiveness and reduced the relaxing effect of aminophylline, as observed in AG. An in silico analysis revealed that LA had a good affinity for nine proteins (β2-adrenergic receptor, CaV, BKCa, KATP, adenylyl cyclase, PKG, eNOS, iNOS, and COX-2).

CONCLUSIONS

LA at 100 mg/kg has low toxicity, prevents hyper-responsiveness in an asthma model in rats, and acts as a multitarget compound with a good affinity for proteins related to airway hyper-responsiveness.

Nitric oxide synthase inhibitors reduce the formation of neutrophil extracellular traps and alleviate airway inflammation in the mice model of asthma

Asthma, a widespread chronic inflammatory disease can contribute to different degrees of lung function damage. The objective of this study is to explore the potential effects of nitric oxide synthase (NOS) inhibitors in asthma using mice model induced by ovalbumin (OVA). BALB/c mice were treated with OVA to establish an asthma model. Mice were intranasally challenged with different NOS inhibitors and analyzed the impact of NOS inhibitors on the lung tissues and bronchoalveolar lavage fluid (BALF). Histopathological analysis was performed by Periodic Acid-Schiff (PAS) staining. Airway reactivity was assessed using methacholine challenge testing. The concentrations of nitric oxide (NO), Neutrophil extracellular traps (NETs), and cytokines were determined by enzyme-linked immunosorbent assay (ELISA) assay. NOS inhibitors effectively improved airway inflammation and reduced airway hyperresponsiveness. In addition, NOS inhibitors decreased the concentrations of NO, NETs, and inflammation in the airway and BALF. The decreased NO production and reduced NET formation in the lung indicate that NOS inhibitors inhibit the process of NET release to alleviate asthma.

Inhalable Mucociliary-On-Chip System Revealing Pulmonary Clearance Dynamics in Nanodrug Delivery

The development of a inhaled nanodrug delivery assessment platform is crucial for advancing treatments for chronic lung diseases. Traditional in vitro models and commercial aerosol systems fail to accurately simulate the complex human respiratory patterns and mucosal barriers. To address this, we have developed the breathing mucociliary-on-a-chip (BMC) platform, which replicates mucociliary clearance and respiratory dynamics in vitro. This platform allows for precise analysis of drug deposition and penetration, providing critical insights into how liposomes and other nanocarriers interact with lung tissues under various airflow conditions. Our results reveal that liposomes penetrate deeper into the cellular layer under high shear stress, with both static and dynamic airflows distinctly affecting their drug release rates. The BMC platform integrates dynamic inhalation systems with mucociliary clearance functionality, enabling a comprehensive evaluation of drug delivery efficacy. This approach highlights the importance of airflow dynamics in optimizing inhalable nanodrug delivery systems, improving nanocarrier design, and tailoring drug dosages and release strategies. The BMC platform represents a significant advancement in the field of inhaled nanodrug delivery, offering a more accurate and reliable method for assessing the performance of therapies. By providing a detailed understanding of drug interactions with lung tissues, this platform supports the development of personalized inhaled therapies and offers promising strategies for treating pulmonary diseases and advancing nanodrug development.

Nitric Oxide Signaling and Sensing in Age-Related Diseases

Nitric oxide (NO) is a key signaling molecule involved in numerous physiological and pathological processes within the human body. This review specifically examines the involvement of NO in age-related diseases, focusing on the cardiovascular, nervous, and immune systems. The discussion delves into the mechanisms of NO signaling in these diseases, emphasizing the post-translational modifications of involved proteins, such as S-nitrosation and nitration. The review also covers the dual nature of NO, highlighting both its protective and harmful effects, determined by concentration, location, and timing. Additionally, potential therapies that modulate NO signaling, including the use of NO donors and nitric oxide synthases (NOSs) inhibitors in the treatment of cardiovascular, neurodegenerative, and oncological diseases, are analyzed. Particular attention is paid to the methods for the determination of NO and its derivatives in the context of illness diagnosis and monitoring. The review underscores the complexity and dual role of NO in maintaining cellular balance and suggests areas for future research in developing new therapeutic strategies.

Bacterial extracellular vesicles as intranasal postbiotics: Detailed characterization and interaction with airway cells

Escherichia coli A0 34/86 (EcO83) is a probiotic strain used in newborns to prevent nosocomial infections and diarrhoea. This bacterium stimulates both pro- and anti-inflammatory cytokine production and its intranasal administration reduces allergic airway inflammation in mice. Despite its benefits, there are concerns about the use of live probiotic bacteria due to potential systemic infections and gene transfer. Extracellular vesicles (EVs) derived from EcO83 (EcO83-EVs) might offer a safer alternative to live bacteria. This study characterizes EcO83-EVs and investigates their interaction with host cells, highlighting their potential as postbiotic therapeutics. EcO83-EVs were isolated, purified, and characterised following the Minimal Information of Studies of Extracellular Vesicles (MISEV) guidelines. Ex vivo studies conducted in human nasal epithelial cells showed that EcO83-EVs increased the expression of proteins linked to oxidative stress and inflammation, indicating an effective interaction between EVs and the host cells. Further in vivo studies in mice demonstrated that EcO83-EVs interact with nasal-associated lymphoid tissue, are internalised by airway macrophages, and stimulate neutrophil recruitment in the lung. Mechanistically, EcO83-EVs activate the NF-κΒ signalling pathway, resulting in the nitric oxide production. EcO83-EVs demonstrate significant potential as a postbiotic alternative to live bacteria, offering a safer option for therapeutic applications. Further research is required to explore their clinical use, particularly in mucosal vaccination and targeted immunotherapy strategies.

Curcumin nanoparticles in heat stroke management

OBJECTIVE

The exacerbation of extreme high-temperature events due to global climate change poses a significant challenge to public health, particularly impacting the central nervous system through heat stroke. This study aims to develop Poly(amidoamine) (PAMAM) nanoparticles loaded with curcumin (PAMAM@Cur) to enhance its therapeutic efficacy in hypothalamic neural damage in a heat stroke model and explore its potential mechanisms.

METHODS

Curcumin (Cur) was encapsulated into PAMAM nanoparticles through a hydrophobic interaction method, and various techniques were employed to characterize their physicochemical properties. A heat stroke mouse model was established to monitor body temperature and serum biochemical parameters, conduct behavioral assessments, histological examinations, and biochemical analyses. Transcriptomic and proteomic analyses were performed to investigate the therapeutic mechanisms of PAMAM@Cur, validated in an N2a cell model.

RESULTS

PAMAM@Cur demonstrated good stability, photostability, cell compatibility, significant blood-brain barrier (BBB) penetration capability, and effective accumulation in the brain. PAMAM@Cur markedly improved behavioral performance and neural cell structural integrity in heat stroke mice, alleviated inflammatory responses, with superior therapeutic effects compared to Cur or PAMAM alone. Multi-omics analysis revealed that PAMAM@Cur regulated antioxidant defense genes and iron death-related genes, particularly upregulating the PCBP2 protein, stabilizing SLC7A11 and GPX4 mRNA, and reducing iron-dependent cell death.

CONCLUSION

By enhancing the drug delivery properties of Cur and modulating molecular pathways relevant to disease treatment, PAMAM@Cur significantly enhances the therapeutic effects against hypothalamic neural damage induced by heat stroke, showcasing the potential of nanotechnology in improving traditional drug efficacy and providing new strategies for future clinical applications.

SIGNIFICANCE

This study highlights the outlook of nanotechnology in treating neurological disorders caused by heat stroke, offering a novel therapeutic approach with potential clinical applications.

Polylactic acid nanoplastics (PLA-NPLs) induce adverse effects on an in vitro model of the human lung epithelium: The Calu-3 air-liquid interface (ALI) barrier

The expected increments in the production/use of bioplastics, as an alternative to petroleum-based plastics, require a deep understanding of their potential environmental and health hazards, mainly as nanoplastics (NPLs). Since one important exposure route to NPLs is through inhalation, this study aims to determine the fate and effects of true-to-life polylactic acid nanoplastics (PLA-NPLs), using the in vitro Calu-3 model of bronchial epithelium, under air-liquid interphase exposure conditions. To determine the harmful effects of PLA-NPLs in a more realistic scenario, both acute (24 h) and long-term (1 and 2 weeks) exposures were used. Flow cytometry results indicated that PLA-NPLs internalized easily in the barrier (∼10 % at 24 h and ∼40 % after 2 weeks), which affected the expression of tight-junctions formation (∼50 % less vs control) and the mucus secretion (∼50 % more vs control), both measured by immunostaining. Interestingly, significant genotoxic effects (DNA breaks) were detected by using the comet assay, with long-term effects being more marked than acute ones (7.01 vs 4.54 % of DNA damage). When an array of cellular proteins including cytokines, chemokines, and growth factors were used, a significant over-expression was mainly found in long-term exposures (∼20 proteins vs 5 proteins after acute exposure). Overall, these results described the potential hazards posed by PLA-NPLs, under relevant long-term exposure scenarios, highlighting the advantages of the model used to study bronchial epithelium tissue damage, and signaling endpoints related to inflammation.

Dietary Beetroot Juice - Effects in Patients with COPD: A Review

Chronic Obstructive Pulmonary Disease (COPD) exerts a severe toll on human health and the economy, with high prevalence and mortality rates. The search for bioactive components effective in the treatment of COPD has become a focal point of research. Beetroot juice, readily accessible and cost-effective, is noted for its ability to enhance athletic performance and for its preventive and therapeutic impact on hypertension. Beetroot juice is a rich source of dietary nitrates and modulates physiological processes via the nitrate-nitrite- nitric oxide pathway, exerting multiple beneficial effects such as antihypertensive, bronchodilatory, anti-inflammatory, antioxidant, hypoglycemic, and lipid-lowering actions. This paper provides a review of the existing research on the effects of beetroot juice on COPD, summarizing its potential in enhancing exercise capacity, lowering blood pressure, improving vascular function, and ameliorating sleep quality among patients with COPD. The review serves as a reference for the prospective use of beetroot juice in the symptomatic improvement of COPD, as well as in the prevention of exacerbations and associated comorbidities.

Association between PRKG1 gene and gene-environment interactions with pediatric asthma

OBJECTIVE

To investigate the relationship between single nucleotide polymorphisms (SNPs) of cGMP-dependent protein kinase I (PRKG1) gene and gene-environment interactions with bronchial asthma in children.

METHODS

109 asthma patients and 158 healthy controls from the General Hospital of Northern Theater Command were enrolled, based case-control study. The iMLDR® multiple SNP typing technique was applied to detect the genotypes of rs7903366, rs7081864, rs7070958 and rs7897633 in PRKG1 gene. The percentage of eosinophils (EOS%) in peripheral blood and serum immunoglobulin E (IgE) in the case group were also measured. Gene-environment interactions were examined using the generalized multi-factor dimensionality reduction (GMDR) method.

RESULTS

There were polymorphisms in four SNPs of PRKG1 gene in the case and control groups. The genotype and allele frequencies distribution of rs7897633 demonstrated statistical significance (p < 0.05). There were no statistically significant differences in EOS% and IgE among genotypes at the four SNPs of PRKG1 gene (p > 0.05). The haplotypes CAGA and TGAC presented significant association with asthma risk (p < 0.05). The four-factor model indicated a potential gene-environment interaction in rs7897633, allergen exposure, residence, and environmental tobacco smoke (ETS) exposure (p < 0.05).

CONCLUSIONS

The rs7897633 in PRKG1 gene was associated with susceptibility to childhood asthma, and C allele is a protective factor. The haplotype CAGA had a protective effect against asthma risk and TGAC was linked to the high risk of developing asthma. Moreover, the interaction of rs7897633, allergen exposure, residence, and ETS exposure conferred susceptibility to childhood asthma.

Inhaled NO at a crossroads in cardiac surgery: current need to improve mechanistic understanding, clinical trial design and scientific evidence

Inhaled nitric oxide (NO) has been used in pediatric and adult perioperative cardiac intensive care for over three decades. NO is a cellular signaling molecule that induces smooth muscle relaxation in the mammalian vasculature. Inhaled NO has the unique ability to exert its vasodilatory effects in the pulmonary vasculature without any hypotensive side-effects in the systemic circulation. In patients undergoing cardiac surgery, NO has been reported in numerous studies to exert beneficial effects on acutely lowering pulmonary artery pressure and reversing right ventricular dysfunction and/or failure. Yet, various investigations failed to demonstrate significant differences in long-term clinical outcomes. The authors, serving as an advisory board of international experts in the field of inhaled NO within pediatric and adult cardiac surgery, will discuss how the existing scientific evidence can be further improved. We will summarize the basic mechanisms underlying the clinical applications of inhaled NO and how this translates into the mandate for inhaled NO in cardiac surgery. We will move on to the popular use of inhaled NO and will talk about the evidence base of the use of this selective pulmonary vasodilator. This review will elucidate what kind of clinical and biological barriers and gaps in knowledge need to be solved and how this has impacted in the development of clinical trials. The authors will elaborate on how the optimization of inhaled NO therapy, the development of biomarkers to identify the target population and the definition of response can improve the design of future large clinical trials. We will explain why it is mandatory to gain an international consensus for the state of the art of NO therapy far beyond this expert advisory board by including the different major players in the field, such as the different medical societies and the pharma industry to improve our understanding of the real-life effects of inhaled NO in large scale observational studies. The design for future innovative randomized controlled trials on inhaled NO therapy in cardiac surgery, adequately powered and based on enhanced biological phenotyping, will be crucial to eventually provide scientific evidence of its clinical efficacy beyond its beneficial hemodynamic properties.

Calcium Signaling in Airway Epithelial Cells: Current Understanding and Implications for Inflammatory Airway Disease

Airway epithelial cells play an indispensable role in protecting the lung from inhaled pathogens and allergens by releasing an array of mediators that orchestrate inflammatory and immune responses when confronted with harmful environmental triggers. While this process is undoubtedly important for containing the effects of various harmful insults, dysregulation of the inflammatory response can cause lung diseases including asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. A key cellular mechanism that underlies the inflammatory responses in the airway is calcium signaling, which stimulates the production and release of chemokines, cytokines, and prostaglandins from the airway epithelium. In this review, we discuss the role of major Ca2+ signaling pathways found in airway epithelial cells and their contributions to airway inflammation, mucociliary clearance, and surfactant production. We highlight the importance of store-operated Ca2+ entry as a major signaling hub in these processes and discuss therapeutic implications of targeting Ca2+ signaling for airway inflammation.

Airway remodelling in asthma and the epithelium: on the edge of a new era

Asthma is a chronic, heterogeneous disease of the airways, often characterised by structural changes known collectively as airway remodelling. In response to environmental insults, including pathogens, allergens and pollutants, the epithelium can initiate remodelling via an inflammatory cascade involving a variety of mediators that have downstream effects on both structural and immune cells. These mediators include the epithelial cytokines thymic stromal lymphopoietin, interleukin (IL)-33 and IL-25, which facilitate airway remodelling through cross-talk between epithelial cells and fibroblasts, and between mast cells and airway smooth muscle cells, as well as through signalling with immune cells such as macrophages. The epithelium can also initiate airway remodelling independently of inflammation in response to the mechanical stress present during bronchoconstriction. Furthermore, genetic and epigenetic alterations to epithelial components are believed to influence remodelling. Here, we review recent advances in our understanding of the roles of the epithelium and epithelial cytokines in driving airway remodelling, facilitated by developments in genetic sequencing and imaging techniques. We also explore how new and existing therapeutics that target the epithelium and epithelial cytokines could modify airway remodelling.

IL-1β and iNOS can drive the asthmatic comorbidities and decrease of lung function in perennial allergic rhinitis children

BACKGROUND

Allergic asthma and rhinitis (AR) are closely linked, with a significant proportion of AR patients developing asthma. Identification of the early signs of comorbidity of AR and asthma can enable prompt treatment and prevent asthma progression.

OBJECTIVES AND METHODS

This study investigated the role of interleukin-1β (IL-1β), a pro-inflammatory cytokine, and inducible nitric oxide synthase (iNOS) in the comorbidity of AR and asthma and lung function in Korean children with perennial AR (PAR). A cohort of 240 subjects (6 to 10 years old) with PAR (PAR alone: 113 children, PAR and asthma: 127 children) was analyzed for various biomarkers, including IL-1β, iNOS, and epithelial-mesenchymal transition (EMT) markers in serum. The blood levels of eosinophils and immunoglobulin E (IgE) were examined. IL-1β, CCL-24, E-cadherin, and vimentin were measured by enzyme-linked immunosorbent assay (ELISA). Epithelial iNOS was measured by the NOS kit.

RESULTS

Elevated levels of IL-1β, iNOS, and vimentin in the serum were identified as significant indicators of the likelihood of comorbidity of PAR and asthma in children. Furthermore, higher concentrations of IL-1β, iNOS, and vimentin have been linked to reduced lung function in PAR children. Notably, IL-1β expression shows a relationship with the levels of E-cadherin, vimentin, and CCL-24. However, no correlation was found between IL-1β and iNOS expressions.

CONCLUSIONS

This study suggests that IL-1β and iNOS can be biomarkers in the progression of PAR and asthma and decreased lung function, suggesting potential targets for early intervention and treatment.

An oral commensal attenuates Pseudomonas aeruginosa-induced airway inflammation and modulates nitrite flux in respiratory epithelium

IMPORTANCE

Respiratory infections are a leading cause of morbidity and mortality in people with cystic fibrosis (CF). These infections are polymicrobial in nature with overt pathogens and other colonizing microbes present. Microbiome data have indicated that the presence of oral commensal bacteria in the lungs is correlated with improved outcomes. We hypothesize that one oral commensal, Streptococcus parasanguinis, inhibits CF pathogens and modulates the host immune response. One major CF pathogen is Pseudomonas aeruginosa, a Gram-negative, opportunistic bacterium with intrinsic drug resistance and an arsenal of virulence factors. We have previously shown that S. parasanguinis inhibits P. aeruginosa in vitro in a nitrite-dependent manner through the production of reactive nitrogen intermediates. In this study, we demonstrate that while this mechanism is evident in a cell culture model of the CF airway, an alternative mechanism by which S. parasanguinis may improve outcomes for people with CF is through immunomodulation.

Beyond epithelial damage: vascular and endothelial contributions to idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive scarring disease of the lung with poor survival. The incidence and mortality of IPF are rising, but treatment remains limited. Currently, two drugs can slow the scarring process but often at the expense of intolerable side effects, and without substantially changing overall survival. A better understanding of mechanisms underlying IPF is likely to lead to improved therapies. The current paradigm proposes that repetitive alveolar epithelial injury from noxious stimuli in a genetically primed individual is followed by abnormal wound healing, including aberrant activity of extracellular matrix-secreting cells, with resultant tissue fibrosis and parenchymal damage. However, this may underplay the importance of the vascular contribution to fibrogenesis. The lungs receive 100% of the cardiac output, and vascular abnormalities in IPF include (a) heterogeneous vessel formation throughout fibrotic lung, including the development of abnormal dilated vessels and anastomoses; (b) abnormal spatially distributed populations of endothelial cells (ECs); (c) dysregulation of endothelial protective pathways such as prostacyclin signaling; and (d) an increased frequency of common vascular and metabolic comorbidities. Here, we propose that vascular and EC abnormalities are both causal and consequential in the pathobiology of IPF and that fuller evaluation of dysregulated pathways may lead to effective therapies and a cure for this devastating disease.

Arginine, Transsulfuration, and Folic Acid Pathway Metabolomics in Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

There is an increasing interest in biomarkers of nitric oxide dysregulation and oxidative stress to guide management and identify new therapeutic targets in patients with chronic obstructive pulmonary disease (COPD). We conducted a systematic review and meta-analysis of the association between circulating metabolites within the arginine (arginine, citrulline, ornithine, asymmetric, ADMA, and symmetric, SDMA dimethylarginine), transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B6, and vitamin B12) metabolic pathways and COPD. We searched electronic databases from inception to 30 June 2023 and assessed the risk of bias and the certainty of evidence. In 21 eligible studies, compared to healthy controls, patients with stable COPD had significantly lower methionine (standardized mean difference, SMD = -0.50, 95% CI -0.95 to -0.05, p = 0.029) and folic acid (SMD = -0.37, 95% CI -0.65 to -0.09, p = 0.009), and higher homocysteine (SMD = 0.78, 95% CI 0.48 to 1.07, p < 0.001) and cysteine concentrations (SMD = 0.34, 95% CI 0.02 to 0.66, p = 0.038). Additionally, COPD was associated with significantly higher ADMA (SMD = 1.27, 95% CI 0.08 to 2.46, p = 0.037), SDMA (SMD = 3.94, 95% CI 0.79 to 7.08, p = 0.014), and ornithine concentrations (SMD = 0.67, 95% CI 0.13 to 1.22, p = 0.015). In subgroup analysis, the SMD of homocysteine was significantly associated with the biological matrix assessed and the forced expiratory volume in the first second to forced vital capacity ratio, but not with age, study location, or analytical method used. Our study suggests that the presence of significant alterations in metabolites within the arginine, transsulfuration, and folic acid pathways can be useful for assessing nitric oxide dysregulation and oxidative stress and identifying novel treatment targets in COPD. (PROSPERO registration number: CRD42023448036.).

Endothelial MICU1 alleviates diabetic cardiomyopathy by attenuating nitrative stress-mediated cardiac microvascular injury

BACKGROUND

Myocardial microvascular injury is the key event in early diabetic heart disease. The injury of myocardial microvascular endothelial cells (CMECs) is the main cause and trigger of myocardial microvascular disease. Mitochondrial calcium homeostasis plays an important role in maintaining the normal function, survival and death of endothelial cells. Considering that mitochondrial calcium uptake 1 (MICU1) is a key molecule in mitochondrial calcium regulation, this study aimed to investigate the role of MICU1 in CMECs and explore its underlying mechanisms.

METHODS

To examine the role of endothelial MICU1 in diabetic cardiomyopathy (DCM), we used endothelial-specific MICU1ecKO mice to establish a diabetic mouse model and evaluate the cardiac function. In addition, MICU1 overexpression was conducted by injecting adeno-associated virus 9 carrying MICU1 (AAV9-MICU1). Transcriptome sequencing technology was used to explore underlying molecular mechanisms.

RESULTS

Here, we found that MICU1 expression is decreased in CMECs of diabetic mice. Moreover, we demonstrated that endothelial cell MICU1 knockout exacerbated the levels of cardiac hypertrophy and interstitial myocardial fibrosis and led to a further reduction in left ventricular function in diabetic mice. Notably, we found that AAV9-MICU1 specifically upregulated the expression of MICU1 in CMECs of diabetic mice, which inhibited nitrification stress, inflammatory reaction, and apoptosis of the CMECs, ameliorated myocardial hypertrophy and fibrosis, and promoted cardiac function. Further mechanistic analysis suggested that MICU1 deficiency result in excessive mitochondrial calcium uptake and homeostasis imbalance which caused nitrification stress-induced endothelial damage and inflammation that disrupted myocardial microvascular endothelial barrier function and ultimately promoted DCM progression.

CONCLUSIONS

Our findings demonstrate that MICU1 expression was downregulated in the CMECs of diabetic mice. Overexpression of endothelial MICU1 reduced nitrification stress induced apoptosis and inflammation by inhibiting mitochondrial calcium uptake, which improved myocardial microvascular function and inhibited DCM progression. Our findings suggest that endothelial MICU1 is a molecular intervention target for the potential treatment of DCM.

Autophagy/Mitophagy in Airway Diseases: Impact of Oxidative Stress on Epithelial Cells

Autophagy is the key process by which the cell degrades parts of itself within the lysosomes. It maintains cell survival and homeostasis by removing molecules (particularly proteins), subcellular organelles, damaged cytoplasmic macromolecules, and by recycling the degradation products. The selective removal or degradation of mitochondria is a particular type of autophagy called mitophagy. Various forms of cellular stress (oxidative stress (OS), hypoxia, pathogen infections) affect autophagy by inducing free radicals and reactive oxygen species (ROS) formation to promote the antioxidant response. Dysfunctional mechanisms of autophagy have been found in different respiratory diseases such as chronic obstructive lung disease (COPD) and asthma, involving epithelial cells. Several existing clinically approved drugs may modulate autophagy to varying extents. However, these drugs are nonspecific and not currently utilized to manipulate autophagy in airway diseases. In this review, we provide an overview of different autophagic pathways with particular attention on the dysfunctional mechanisms of autophagy in the epithelial cells during asthma and COPD. Our aim is to further deepen and disclose the research in this direction to stimulate the develop of new and selective drugs to regulate autophagy for asthma and COPD treatment.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Nitric oxide hinders club cell proliferation through Gdpd2 during allergic airway inflammation

Excessive nitric oxide (NO) is often observed in the airways of patients with severe asthma. Here, we show that the NO donor diethylamine NONOate impairs the proliferative capacity of mouse club cells and induces club cell apoptosis, cell cycle arrest, and alterations in lipid metabolism. Our data suggest that NO inhibits club cell proliferation via upregulation of Gdpd2 (glycerophosphodiester phosphodiesterase domain containing 2). During ovalbumin (OVA) challenge, apoptotic club cells are observed, but surviving club cells continue to proliferate. OVA exposure induces Gdpd2 expression; Gdpd2 knockout promotes the proliferation of club cells but inhibits goblet cell differentiation. Elimination of airway NO was found to inhibit goblet cell differentiation from club cells during OVA challenge. Our data reveal that excessive NO might be related to airway epithelial damage in severe asthma and suggest that blockade of the NO-Gdpd2 pathway may be beneficial for airway epithelial restoration.

Azithromycin ameliorated cigarette smoke-induced airway epithelial barrier dysfunction by activating Nrf2/GCL/GSH signaling pathway

BACKGROUND

Airway epithelium is the first barrier against environmental insults, and epithelial barrier dysfunction caused by cigarette smoke (CS) is particularly relevant to chronic obstructive pulmonary disease (COPD) progression. Our study was to determine whether Azithromycin (AZI) ameliorates CS-induced airway epithelial barrier dysfunction and the underlying mechanisms.

METHODS

Primary bronchial epithelial cells (PBECs), human bronchial epithelial cells (HBECs), Sprague Dawley rats and nuclear factor erythroid 2-related factor 2 (Nrf2)-/- mice were pretreated with AZI and subsequently exposed to CS. Transepithelial electronic resistance (TEER), junction proteins as well as pro-inflammatory cytokines and apoptosis markers were examined to assess epithelial barrier dysfunction. Metabolomics study was applied to explore the underlying mechanism of AZI.

RESULTS

CS-induced TEER decline and intercellular junction destruction, accompanied with inflammatory response and cell apoptosis in PBECs were restored by AZI dose-dependently, which were also observed in CS-exposed rats. Mechanistically, GSH metabolism pathway was identified as the top differentially impacted pathway and AZI treatment upregulated the activities of glutamate cysteine ligase (GCL) and the contents of metabolites in GSH metabolic pathway. Furthermore, AZI apparently reversed CS-induced Nrf2 suppression, and similar effects on airway epithelial barrier dysfunction were also found for Nrf2 agonist tert-butylhydroquinone and vitamin C. Finally, deletion of Nrf2 in both HBECs and C57BL/6N mice aggravated CS-induced GSH metabolism imbalance to disrupt airway epithelial barrier and partially deprived the effects of AZI.

CONCLUSION

These findings suggest that the clinical benefits of AZI for COPD management are related with the protection of CS-induced airway epithelial barrier dysfunction via activating Nrf2/GCL/GSH pathway, providing potential therapeutic strategies for COPD.

Female-biased association of NOS2-c.1823C>T (rs2297518) with co-susceptibility to metabolic syndrome and asthma

The nitric oxide (NO) pathway contributes to the pathogeneses of metabolic syndrome (MetS) and asthma. NOS2 encodes inducible-NO synthase, which is an important enzyme of the pathway, and its variations could affect the risk of asthma and MetS and thereby co-susceptibility to them. This study aims to estimate the association of NOS2-c.1823C>T with risk of asthma, MetS, and asthma with MetS condition (ASMetS), and with asthma stages: intermittent, mild, moderate, and severe asthma. The study included asthmatics (n = 555), MetS (n = 334), and ASMetS cases (n = 232) and 351 controls, which were genotyped by the PCR-RFLP method. The T allele was significantly associated with an increased risk of asthma and MetS in the sample population and females. CT genotype and CT+TT model were significantly associated with increased risk of ASMetS in females. A significant association between CT genotype and increased risk of ASMetS in the sample population and females was found in ASMetS versus MetS. In the sample population and among females, the T allele was significantly associated with severe asthma. The rs2297518 single nucleotide polymorphism of NOS2 contributes to the risk of MetS, asthma, and co-susceptibility to them, and this contribution may be stronger in females compared to males.

S-Nitrosoglutathione Reduces the Density of Staphylococcus aureus Biofilms Established on Human Airway Epithelial Cells

Patients with chronic rhinosinusitis (CRS) often show persistent colonization by bacteria in the form of biofilms which are resistant to antibiotic treatment. One of the most commonly isolated bacteria in CRS is Staphylococcus aureus (S. aureus). Nitric oxide (NO) is a potent antimicrobial agent and disperses biofilms efficiently. We hypothesized that S-nitrosoglutathione (GSNO), an endogenous NO carrier/donor, synergizes with gentamicin to disperse and reduce the bacterial biofilm density. We prepared GSNO formulations which are stable up to 12 months at room temperature and show the maximum amount of NO release within 1 h. We examined the effects of this GSNO formulation on the S. aureus biofilm established on the apical surface of the mucociliary-differentiated airway epithelial cell cultures regenerated from airway basal (stem) cells from cystic fibrosis (CF) and CRS patients. We demonstrate that for CF cells, which are defective in producing NO, treatment with GSNO at 100 μM increased the NO levels on the apical surface and reduced the biofilm bacterial density by 2 log units without stimulating pro-inflammatory effects or inducing epithelial cell death. In combination with gentamicin, GSNO further enhanced the killing of biofilm bacteria. Compared to placebo, GSNO significantly increased the ciliary beat frequency (CBF) in both infected and uninfected CF cell cultures. The combination of GSNO and gentamicin also reduced the bacterial density of biofilms grown on sinonasal epithelial cells from CRS patients and improved the CBF. These findings demonstrate that GSNO in combination with gentamicin may effectively reduce the density of biofilm bacteria in CRS patients. GSNO treatment may also enhance the mucociliary clearance by improving the CBF.

Halotherapy relieves chronic obstructive pulmonary disease by alleviating NLRP3 inflammasome-mediated pyroptosis

Background

Airway remodeling and inflammation are considered the main characteristics of chronic obstructive pulmonary disease (COPD). Cigarette smoke promotes the occurrence of inflammation, oxidative stress, and pyroptosis. Halotherapy has been shown to dilute secretions in the airways and promote drainage, but the mechanism remains unclear. In this study, we evaluated the anti-inflammatory and antioxidant effects of halotherapy in COPD rats and investigated the underlying mechanism.

Methods

A COPD rat model was constructed by cigarette smoke and lipopolysaccharide tracheal instillation. A total of 120 male Sprague-Dawley (SD) rats were randomly divided into control, model, halotherapy, terbutaline, halotherapy + terbutaline, and Ac-YVAD-CMK (Caspase-1 inhibitor) groups. After modeling and treatment, the pulmonary function of the rats was measured. Pathological changes in the lungs were measured by hematoxylin-eosin (H&E) staining. Serum interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), and nitric oxide (NO) levels were determined using enzyme-linked immunosorbent assay (ELISA) kits. Malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity in the lungs were determined by biochemical tests. The levels of cluster of differentiation 4 (CD4⁺) and CD8⁺ T cells in the blood were determined by flow cytometry. The expression levels of Toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), gasdermin-D (GSDMD), nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), Caspase-1, and IL-1β in lung tissues were detected by immunohistochemistry, Western blotting, or quantitative polymerase chain reaction (qPCR).

Results

Halotherapy recovered the clinical symptoms of COPD rats, and reduced lung inflammatory cell infiltration and air wall attenuation. It also relieved oxidative stress in the lung tissue of COPD rats, reduced CD4⁺ and CD8⁺ T cell accumulation in lung tissue, and decreased inflammatory factor production in the serum of COPD rats. Furthermore, it inhibited the TLR4/NF-κB/GSDMD and NLRP3/ASC/Caspase-1 signaling pathways. Ac-YVAD-CMK could not completely inhibit the therapeutic effect of halotherapy on COPD rats.

Conclusions

Halotherapy improves lung function by inhibiting the NLRP3/ASC/Caspase-1 signaling pathway to reduce inflammation and pyroptosis in COPD rats, and may be a new option for the prevention and treatment of COPD.

Overview of the Mechanisms of Oxidative Stress: Impact in Inflammation of the Airway Diseases

Inflammation of the human lung is mediated in response to different stimuli (e.g., physical, radioactive, infective, pro-allergenic or toxic) such as cigarette smoke and environmental pollutants. They often promote an increase in inflammatory activities in the airways that manifest themselves as chronic diseases (e.g., allergic airway diseases, asthma, chronic bronchitis/chronic obstructive pulmonary disease (COPD) or even lung cancer). Increased levels of oxidative stress (OS) reduce the antioxidant defenses, affect the autophagy/mitophagy processes, and the regulatory mechanisms of cell survival, promoting inflammation in the lung. In fact, OS potentiate the inflammatory activities in the lung, favoring the progression of chronic airway diseases. OS increases the production of reactive oxygen species (ROS), including superoxide anions (O₂^-), hydroxyl radicals (OH) and hydrogen peroxide (H₂O₂), by the transformation of oxygen through enzymatic and non-enzymatic reactions. In this manner, OS reduces endogenous antioxidant defenses in both nucleated and non-nucleated cells. The production of ROS in the lung can derive from both exogenous insults (cigarette smoke or environmental pollution) and endogenous sources such as cell injury and/or activated inflammatory and structural cells. In this review, we describe the most relevant knowledge concerning the functional interrelation between the mechanisms of OS and inflammation in airway diseases.

The role of sulfur compounds in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease that brings about great social and economic burden, with oxidative stress and inflammation affecting the whole disease progress. Sulfur compounds such as hydrogen sulfide (H₂S), thiols, and persulfides/polysulfides have intrinsic antioxidant and anti-inflammatory ability, which is engaged in the pathophysiological process of COPD. Hydrogen sulfide mainly exhibits its function by S-sulfidation of the cysteine residue of the targeted proteins. It also interacts with nitric oxide and acts as a potential biomarker for the COPD phenotype. Thiols’ redox buffer such as the glutathione redox couple is a major non-enzymatic redox buffer reflecting the oxidative stress in the organism. The disturbance of redox buffers was often detected in patients with COPD, and redressing the balance could delay COPD exacerbation. Sulfane sulfur refers to a divalent sulfur atom bonded with another sulfur atom. Among them, persulfides and polysulfides have an evolutionarily conserved modification with antiaging effects. Sulfur compounds and their relative signaling pathways are also associated with the development of comorbidities in COPD. Synthetic compounds which can release H₂S and persulfides in the organism have gradually been developed. Naturally extracted sulfur compounds with pharmacological effects also aroused great interest. This study discussed the biological functions and mechanisms of sulfur compounds in regulating COPD and its comorbidities.

Inflammation resolution in environmental pulmonary health and morbidity

Inflammation and resolution are dynamic processes comprised of inflammatory activation and neutrophil influx, followed by mediator catabolism and efferocytosis. These critical pathways ensure a return to homeostasis and promote repair. Over the past decade research has shown that diverse mediators play a role in the active process of resolution. Specialized pro-resolving mediators (SPMs), biosynthesized from fatty acids, are released during inflammation to facilitate resolution and are deficient in a variety of lung disorders. Failed resolution results in remodeling and cellular deposition through pro-fibrotic myofibroblast expansion that irreversibly narrows the airways and worsens lung function. Recent studies indicate environmental exposures may perturb and deregulate critical resolution pathways. Environmental xenobiotics induce lung inflammation and generate reactive metabolites that promote oxidative stress, injuring the respiratory mucosa and impairing gas-exchange. This warrants recognition of xenobiotic associated molecular patterns (XAMPs) as new signals in the field of inflammation biology, as many environmental chemicals generate free radicals capable of initiating the inflammatory response. Recent studies suggest that unresolved, persistent inflammation impacts both resolution pathways and endogenous regulatory mediators, compromising lung function, which over time can progress to chronic lung disease. Chronic ozone (O3) exposure overwhelms successful resolution, and in susceptible individuals promotes asthma onset. The industrial contaminant cadmium (Cd) bioaccumulates in the lung to impair resolution, and recurrent inflammation can result in chronic obstructive pulmonary disease (COPD). Persistent particulate matter (PM) exposure increases systemic cardiopulmonary inflammation, which reduces lung function and can exacerbate asthma, COPD, and idiopathic pulmonary fibrosis (IPF). While recurrent inflammation underlies environmentally induced pulmonary morbidity and may drive the disease process, our understanding of inflammation resolution in this context is limited. This review aims to explore inflammation resolution biology and its role in chronic environmental lung disease(s).

The Specific microRNA Profile and Functional Networks for Children with Allergic Asthma

Background

Allergic asthma is the most common type of asthma and often occurs in early life with increasing comorbidities, including atopic dermatitis and allergic rhinitis. MicroRNAs (miRNAs) are involved in the pathogenesis of numerous immune and inflammatory disorders, particularly allergic inflammation. The specific miRNA profiles of children with allergic asthma have not been fully delineated and still require in-depth study.

Objective

This study aimed to identify the expression profile of miRNAs and constructed a network of the interactions between differentially expressed miRNAs and target mRNAs to provide novel insights into understanding the pathogenesis of allergic asthma.

Materials and Methods

In this study, we performed high-throughput sequencing of peripheral blood mononuclear cells (PBMCs) from children in the acute phase of asthma. Bioinformatics approaches, including miRanda, Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, were employed to predict novel therapeutic and diagnostic targets for allergic asthma. Real-time quantitative PCR was conducted to detect the expression of aberrantly expressed miRNAs.

Results

One hundred and sixty-one differentially expressed miRNAs were identified in children with allergic asthma, including 140 conserved miRNAs and 21 novel miRNAs. A total of 8929 targeted mRNAs (44,186 transcripts) associated with differentially expressed miRNAs were predicted and significantly enriched in the cGMP-PKG signalling pathway, cholinergic synapse, and salivary secretion. We also found that miRNA-370-3p targeted PKG and MLCP molecules in the cGMP-PKG signalling pathway and was involved in the pathogenesis of allergic asthma.

Conclusion

We identified the miRNA profile of PBMCs in children with allergic asthma and also found that miRNA-370-3p targeted PKG and MLCP molecules in the cGMP-PKG signalling pathway, which provides a novel insight into understanding the pathogenesis of allergic asthma and investigating new targets for the treatment of allergic asthma in children.

Complete Genome Sequence and Cosmetic Potential of Viridibacillus sp. JNUCC6 Isolated from Baengnokdam, the Summit Crater of Mt. Halla

Novel microbe-derived products are gaining increasing attention for their ability to modulate skin conditions. The use of microbial metabolites to improve skin health outcomes is of particular interest because growing evidence points to the importance of natural products without side effects on human health. This study aimed to sequence the genome of Viridibacillus sp. JNUCC6 isolated from Baengnokdam, the summit crater of Mt. Halla. We further investigated the potential use of its extract as a cosmetic ingredient in controlling melanogenesis and inflammation. The genome of this strain was sequenced using both Illumina Novaseq 6000 and third-generation sequencing technology (PacBio RSII) to obtain trustworthy assembly and annotation. Different concentrations of the Viridibacillus sp. JNUCC6 extract were tested for its anti-melanogenic and anti-inflammatory effects in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma and lipopolysaccharide (LPS)-activated RAW 264.7 cells, respectively. The whole genome sequence of the strain contained 4,526,142 bp with 35.61% GC content, one contig, and 4364 protein-coding sequences. Furthermore, antiSMASH analysis of the whole genome revealed three putative biosynthetic gene clusters that are responsible for the production of various secondary metabolites. Our study found that the Viridibacillus sp. JNUCC6 extract inhibited the α-MSH-induced melanin production and tyrosinase activity in B16F10 melanoma cells. In addition, it decreased the LPS-induced nitric oxide (NO) production caused by LPS stimulation in a concentration-dependent manner. Therefore, Viridibacillus sp. JNUCC6 has potential applications as an ingredient in skin-whitening and anti-inflammatory products and can be used in the cosmetic and medical industries.

Clinical Characteristics and Management Strategies for Adult Obese Asthma Patients

The rates of asthma and obesity are increasing concurrently in the United States. Epidemiologic studies demonstrate that the incidence of asthma increases with obesity. Furthermore, obese individuals have asthma that is more severe, harder to control, and resistant to standard medications. In fact, specific asthma-obesity phenotypes have been identified. Various pathophysiologic mechanisms, including mechanical, inflammatory, metabolic and microbiome-associated, are at play in promulgating the obese-asthma phenotypes. While standard asthma medications, such as inhaled corticosteroids and biologics, are currently used to treat obese asthmatics, they may have limited effectiveness. Targeting the underlying aberrant processes, such as addressing steroid resistance, microbiome, metabolic and weight loss approaches, may be helpful.

The Role of Defective Epithelial Barriers in Allergic Lung Disease and Asthma Development

The respiratory epithelium constitutes the physical barrier between the human body and the environment, thus providing functional and immunological protection. It is often exposed to allergens, microbial substances, pathogens, pollutants, and environmental toxins, which lead to dysregulation of the epithelial barrier and result in the chronic inflammation seen in allergic diseases and asthma. This epithelial barrier dysfunction results from the disturbed tight junction formation, which are multi-protein subunits that promote cell-cell adhesion and barrier integrity. The increasing interest and evidence of the role of impaired epithelial barrier function in allergy and asthma highlight the need for innovative approaches that can provide new knowledge in this area. Here, we review and discuss the current role and mechanism of epithelial barrier dysfunction in developing allergic diseases and the effect of current allergy therapies on epithelial barrier restoration.

NO in Viral Infections: Role and Development of Antiviral Therapies

Nitric oxide is a ubiquitous signaling radical that influences critical body functions. Its importance in the cardiovascular system and the innate immune response to bacterial and viral infections has been extensively investigated. The overproduction of NO is an early component of viral infections, including those affecting the respiratory tract. The production of high levels of NO is due to the overexpression of NO biosynthesis by inducible NO synthase (iNOS), which is involved in viral clearance. The development of NO-based antiviral therapies, particularly gaseous NO inhalation and NO-donors, has proven to be an excellent antiviral therapeutic strategy. The aim of this review is to systematically examine the multiple research studies that have been carried out to elucidate the role of NO in viral infections and to comprehensively describe the NO-based antiviral strategies that have been developed thus far. Particular attention has been paid to the potential mechanisms of NO and its clinical use in the prevention and therapy of COVID-19.

Involvement of the Innate Immune System in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common, socially significant disease characterized by progressive airflow limitation due to chronic inflammation in the bronchi. Although the causes of COPD are considered to be known, the pathogenesis of the disease continues to be a relevant topic of study. Mechanisms of the innate immune system are involved in various links in the pathogenesis of COPD, leading to persistence of chronic inflammation in the bronchi, their bacterial colonization and disruption of lung structure and function. Bronchial epithelial cells, neutrophils, macrophages and other cells are involved in the development and progression of the disease, demonstrating multiple compromised immune mechanisms.

Nationwide survey of refractory asthma with bronchiectasis by inflammatory subtypes

RATIONALE

Bronchiectasis and bronchiolitis are differential diagnoses of asthma; moreover, they are factors associated with worse asthma control.

OBJECTIVE

We determined clinical courses of bronchiectasis/bronchiolitis-complicated asthma by inflammatory subtypes as well as factors affecting them.

METHODS

We conducted a survey of refractory asthma with non-cystic fibrosis bronchiectasis/bronchiolitis in Japan. Cases were classified into three groups, based on the latest fractional exhaled NO (FeNO) level (32 ppb for the threshold) and blood eosinophil counts (320/µL for the threshold): high (type 2-high) or low (type 2-low) FeNO and eosinophil and high FeNO or eosinophil (type 2-intermediate). Clinical courses in groups and factors affecting them were analysed.

RESULTS

In total, 216 cases from 81 facilities were reported, and 142 were stratified: 34, 40 and 68 into the type 2-high, -intermediate and -low groups, respectively. The frequency of bronchopneumonia and exacerbations requiring antibiotics and gram-negative bacteria detection rates were highest in the type 2-low group. Eighty-seven cases had paired latest and oldest available data of FeNO and eosinophil counts; they were analysed for inflammatory transition patterns. Among former type 2-high and -intermediate groups, 32% had recently transitioned to the -low group, to which relatively low FeNO in the past and oral corticosteroid use contributed. Lastly, in cases treated with moderate to high doses of inhaled corticosteroids, the frequencies of exacerbations requiring antibiotics were found to be higher in cases with more severe airway lesions and lower FeNO.

CONCLUSIONS

Bronchiectasis/bronchiolitis-complicated refractory asthma is heterogeneous. In patients with sputum symptoms and low FeNO, airway colonisation of pathogenic bacteria and infectious episodes are common; thus, corticosteroids should be carefully used.